freebsd-nq/sys/fs/devfs/devfs_devs.c

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/*-
* Copyright (c) 2000,2004
* Poul-Henning Kamp. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vfsops.c 1.36
*
* $FreeBSD$
*/
#include "opt_mac.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/dirent.h>
#include <sys/kernel.h>
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/proc.h>
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/vnode.h>
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
#include <sys/kdb.h>
#include <fs/devfs/devfs.h>
#include <fs/devfs/devfs_int.h>
#include <security/mac/mac_framework.h>
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
/*
* The one true (but secret) list of active devices in the system.
* Locked by dev_lock()/devmtx
*/
struct cdev_priv_list cdevp_list = TAILQ_HEAD_INITIALIZER(cdevp_list);
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
struct unrhdr *devfs_inos;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
static MALLOC_DEFINE(M_DEVFS2, "DEVFS2", "DEVFS data 2");
static MALLOC_DEFINE(M_DEVFS3, "DEVFS3", "DEVFS data 3");
static MALLOC_DEFINE(M_CDEVP, "DEVFS1", "DEVFS cdev_priv storage");
2000-12-08 15:07:24 +00:00
2005-02-10 12:23:29 +00:00
static SYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "DEVFS filesystem");
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
static unsigned devfs_generation;
SYSCTL_UINT(_vfs_devfs, OID_AUTO, generation, CTLFLAG_RD,
&devfs_generation, 0, "DEVFS generation number");
unsigned devfs_rule_depth = 1;
SYSCTL_UINT(_vfs_devfs, OID_AUTO, rule_depth, CTLFLAG_RW,
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
&devfs_rule_depth, 0, "Max depth of ruleset include");
/*
* Helper sysctl for devname(3). We're given a struct cdev * and return
* the name, if any, registered by the device driver.
*/
static int
sysctl_devname(SYSCTL_HANDLER_ARGS)
{
int error;
dev_t ud;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
struct cdev_priv *cdp;
error = SYSCTL_IN(req, &ud, sizeof (ud));
if (error)
return (error);
if (ud == NODEV)
return(EINVAL);
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
/*
ud ^ devfs_random();
*/
dev_lock();
TAILQ_FOREACH(cdp, &cdevp_list, cdp_list)
if (cdp->cdp_inode == ud)
break;
dev_unlock();
if (cdp == NULL)
return(ENOENT);
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
return(SYSCTL_OUT(req, cdp->cdp_c.si_name, strlen(cdp->cdp_c.si_name) + 1));
return (error);
}
SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY,
NULL, 0, sysctl_devname, "", "devname(3) handler");
SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev, CTLFLAG_RD,
0, sizeof(struct cdev), "sizeof(struct cdev)");
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
SYSCTL_INT(_debug_sizeof, OID_AUTO, cdev_priv, CTLFLAG_RD,
0, sizeof(struct cdev_priv), "sizeof(struct cdev_priv)");
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
struct cdev *
devfs_alloc(void)
{
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
struct cdev_priv *cdp;
struct cdev *cdev;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
cdp = malloc(sizeof *cdp, M_CDEVP, M_USE_RESERVE | M_ZERO | M_WAITOK);
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
cdp->cdp_dirents = &cdp->cdp_dirent0;
cdp->cdp_dirent0 = NULL;
cdp->cdp_maxdirent = 0;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
cdev = &cdp->cdp_c;
cdev->si_priv = cdp;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
cdev->si_name = cdev->__si_namebuf;
LIST_INIT(&cdev->si_children);
return (cdev);
}
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
void
devfs_free(struct cdev *cdev)
{
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
struct cdev_priv *cdp;
cdp = cdev->si_priv;
if (cdev->si_cred != NULL)
crfree(cdev->si_cred);
if (cdp->cdp_inode > 0)
free_unr(devfs_inos, cdp->cdp_inode);
if (cdp->cdp_maxdirent > 0)
free(cdp->cdp_dirents, M_DEVFS2);
free(cdp, M_CDEVP);
}
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
struct devfs_dirent *
devfs_find(struct devfs_dirent *dd, const char *name, int namelen)
{
struct devfs_dirent *de;
TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
if (namelen != de->de_dirent->d_namlen)
continue;
if (bcmp(name, de->de_dirent->d_name, namelen) != 0)
continue;
break;
}
return (de);
}
struct devfs_dirent *
devfs_newdirent(char *name, int namelen)
{
int i;
struct devfs_dirent *de;
struct dirent d;
d.d_namlen = namelen;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
i = sizeof (*de) + GENERIC_DIRSIZ(&d);
de = malloc(i, M_DEVFS3, M_WAITOK | M_ZERO);
de->de_dirent = (struct dirent *)(de + 1);
de->de_dirent->d_namlen = namelen;
de->de_dirent->d_reclen = GENERIC_DIRSIZ(&d);
bcopy(name, de->de_dirent->d_name, namelen);
de->de_dirent->d_name[namelen] = '\0';
vfs_timestamp(&de->de_ctime);
de->de_mtime = de->de_atime = de->de_ctime;
de->de_links = 1;
de->de_holdcnt = 1;
#ifdef MAC
mac_init_devfs(de);
#endif
return (de);
}
struct devfs_dirent *
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
devfs_vmkdir(struct devfs_mount *dmp, char *name, int namelen, struct devfs_dirent *dotdot, u_int inode)
{
struct devfs_dirent *dd;
struct devfs_dirent *de;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
/* Create the new directory */
dd = devfs_newdirent(name, namelen);
TAILQ_INIT(&dd->de_dlist);
dd->de_dirent->d_type = DT_DIR;
dd->de_mode = 0555;
dd->de_links = 2;
dd->de_dir = dd;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
if (inode != 0)
dd->de_inode = inode;
else
dd->de_inode = alloc_unr(devfs_inos);
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
/* Create the "." entry in the new directory */
de = devfs_newdirent(".", 1);
de->de_dirent->d_type = DT_DIR;
de->de_flags |= DE_DOT;
TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
de->de_dir = dd;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
/* Create the ".." entry in the new directory */
de = devfs_newdirent("..", 2);
de->de_dirent->d_type = DT_DIR;
de->de_flags |= DE_DOTDOT;
TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
if (dotdot == NULL) {
de->de_dir = dd;
} else {
de->de_dir = dotdot;
TAILQ_INSERT_TAIL(&dotdot->de_dlist, dd, de_list);
dotdot->de_links++;
}
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
#ifdef MAC
mac_create_devfs_directory(dmp->dm_mount, name, namelen, dd);
#endif
return (dd);
}
void
devfs_dirent_free(struct devfs_dirent *de)
{
free(de, M_DEVFS3);
}
/*
* The caller needs to hold the dm for the duration of the call since
* dm->dm_lock may be temporary dropped.
*/
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
void
devfs_delete(struct devfs_mount *dm, struct devfs_dirent *de, int vp_locked)
{
struct vnode *vp;
struct thread *td;
KASSERT((de->de_flags & DE_DOOMED) == 0,
("devfs_delete doomed dirent"));
td = curthread;
de->de_flags |= DE_DOOMED;
mtx_lock(&devfs_de_interlock);
vp = de->de_vnode;
if (vp != NULL) {
VI_LOCK(vp);
mtx_unlock(&devfs_de_interlock);
vholdl(vp);
sx_unlock(&dm->dm_lock);
if (!vp_locked)
vn_lock(vp, LK_EXCLUSIVE | LK_INTERLOCK | LK_RETRY, td);
else
VI_UNLOCK(vp);
vgone(vp);
if (!vp_locked)
VOP_UNLOCK(vp, 0, td);
vdrop(vp);
sx_xlock(&dm->dm_lock);
} else
mtx_unlock(&devfs_de_interlock);
if (de->de_symlink) {
2005-09-15 10:28:19 +00:00
free(de->de_symlink, M_DEVFS);
de->de_symlink = NULL;
}
#ifdef MAC
mac_destroy_devfs(de);
#endif
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
if (de->de_inode > DEVFS_ROOTINO) {
free_unr(devfs_inos, de->de_inode);
de->de_inode = 0;
}
if (DEVFS_DE_DROP(de))
devfs_dirent_free(de);
}
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
/*
* Called on unmount.
* Recursively removes the entire tree.
* The caller needs to hold the dm for the duration of the call.
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
*/
static void
devfs_purge(struct devfs_mount *dm, struct devfs_dirent *dd)
{
struct devfs_dirent *de;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
sx_assert(&dm->dm_lock, SX_XLOCKED);
for (;;) {
de = TAILQ_FIRST(&dd->de_dlist);
if (de == NULL)
break;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
TAILQ_REMOVE(&dd->de_dlist, de, de_list);
if (de->de_flags & (DE_DOT|DE_DOTDOT))
devfs_delete(dm, de, 0);
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
else if (de->de_dirent->d_type == DT_DIR)
devfs_purge(dm, de);
else
devfs_delete(dm, de, 0);
}
devfs_delete(dm, dd, 0);
}
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
/*
* Each cdev_priv has an array of pointers to devfs_dirent which is indexed
* by the mount points dm_idx.
* This function extends the array when necessary, taking into account that
* the default array is 1 element and not malloc'ed.
*/
static void
devfs_metoo(struct cdev_priv *cdp, struct devfs_mount *dm)
{
struct devfs_dirent **dep;
int siz;
siz = (dm->dm_idx + 1) * sizeof *dep;
dep = malloc(siz, M_DEVFS2, M_WAITOK | M_ZERO);
dev_lock();
if (dm->dm_idx <= cdp->cdp_maxdirent) {
/* We got raced */
dev_unlock();
free(dep, M_DEVFS2);
return;
}
memcpy(dep, cdp->cdp_dirents, (cdp->cdp_maxdirent + 1) * sizeof *dep);
if (cdp->cdp_maxdirent > 0)
free(cdp->cdp_dirents, M_DEVFS2);
cdp->cdp_dirents = dep;
/*
* XXX: if malloc told us how much we actually got this could
* XXX: be optimized.
*/
cdp->cdp_maxdirent = dm->dm_idx;
dev_unlock();
}
/*
* The caller needs to hold the dm for the duration of the call.
*/
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
static int
devfs_populate_loop(struct devfs_mount *dm, int cleanup)
{
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
struct cdev_priv *cdp;
struct devfs_dirent *de;
struct devfs_dirent *dd;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
struct cdev *pdev;
int j;
char *q, *s;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
sx_assert(&dm->dm_lock, SX_XLOCKED);
dev_lock();
TAILQ_FOREACH(cdp, &cdevp_list, cdp_list) {
KASSERT(cdp->cdp_dirents != NULL, ("NULL cdp_dirents"));
/*
* If we are unmounting, or the device has been destroyed,
* clean up our dirent.
*/
if ((cleanup || !(cdp->cdp_flags & CDP_ACTIVE)) &&
dm->dm_idx <= cdp->cdp_maxdirent &&
cdp->cdp_dirents[dm->dm_idx] != NULL) {
de = cdp->cdp_dirents[dm->dm_idx];
cdp->cdp_dirents[dm->dm_idx] = NULL;
KASSERT(cdp == de->de_cdp,
("%s %d %s %p %p", __func__, __LINE__,
cdp->cdp_c.si_name, cdp, de->de_cdp));
KASSERT(de->de_dir != NULL, ("Null de->de_dir"));
dev_unlock();
TAILQ_REMOVE(&de->de_dir->de_dlist, de, de_list);
de->de_cdp = NULL;
de->de_inode = 0;
devfs_delete(dm, de, 0);
dev_lock();
cdp->cdp_inuse--;
dev_unlock();
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
return (1);
}
/*
* GC any lingering devices
*/
if (!(cdp->cdp_flags & CDP_ACTIVE)) {
if (cdp->cdp_inuse > 0)
continue;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
dev_unlock();
dev_rel(&cdp->cdp_c);
return (1);
}
/*
* Don't create any new dirents if we are unmounting
*/
if (cleanup)
continue;
KASSERT((cdp->cdp_flags & CDP_ACTIVE), ("Bogons, I tell ya'!"));
if (dm->dm_idx <= cdp->cdp_maxdirent &&
cdp->cdp_dirents[dm->dm_idx] != NULL) {
de = cdp->cdp_dirents[dm->dm_idx];
KASSERT(cdp == de->de_cdp, ("inconsistent cdp"));
continue;
}
cdp->cdp_inuse++;
dev_unlock();
if (dm->dm_idx > cdp->cdp_maxdirent)
devfs_metoo(cdp, dm);
dd = dm->dm_rootdir;
s = cdp->cdp_c.si_name;
for (;;) {
for (q = s; *q != '/' && *q != '\0'; q++)
continue;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
if (*q != '/')
break;
de = devfs_find(dd, s, q - s);
if (de == NULL)
de = devfs_vmkdir(dm, s, q - s, dd, 0);
s = q + 1;
dd = de;
}
de = devfs_newdirent(s, q - s);
if (cdp->cdp_c.si_flags & SI_ALIAS) {
de->de_uid = 0;
de->de_gid = 0;
de->de_mode = 0755;
de->de_dirent->d_type = DT_LNK;
pdev = cdp->cdp_c.si_parent;
j = strlen(pdev->si_name) + 1;
de->de_symlink = malloc(j, M_DEVFS, M_WAITOK);
bcopy(pdev->si_name, de->de_symlink, j);
} else {
de->de_uid = cdp->cdp_c.si_uid;
de->de_gid = cdp->cdp_c.si_gid;
de->de_mode = cdp->cdp_c.si_mode;
de->de_dirent->d_type = DT_CHR;
}
de->de_inode = cdp->cdp_inode;
de->de_cdp = cdp;
#ifdef MAC
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
mac_create_devfs_device(cdp->cdp_c.si_cred, dm->dm_mount,
&cdp->cdp_c, de);
#endif
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
de->de_dir = dd;
TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
devfs_rules_apply(dm, de);
dev_lock();
/* XXX: could check that cdp is still active here */
KASSERT(cdp->cdp_dirents[dm->dm_idx] == NULL,
("%s %d\n", __func__, __LINE__));
cdp->cdp_dirents[dm->dm_idx] = de;
KASSERT(de->de_cdp != (void *)0xdeadc0de,
("%s %d\n", __func__, __LINE__));
dev_unlock();
return (1);
}
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
dev_unlock();
return (0);
}
/*
* The caller needs to hold the dm for the duration of the call.
*/
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
void
devfs_populate(struct devfs_mount *dm)
{
sx_assert(&dm->dm_lock, SX_XLOCKED);
if (dm->dm_generation == devfs_generation)
return;
while (devfs_populate_loop(dm, 0))
continue;
dm->dm_generation = devfs_generation;
}
/*
* The caller needs to hold the dm for the duration of the call.
*/
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
void
devfs_cleanup(struct devfs_mount *dm)
{
sx_assert(&dm->dm_lock, SX_XLOCKED);
while (devfs_populate_loop(dm, 1))
continue;
devfs_purge(dm, dm->dm_rootdir);
}
/*
* devfs_create() and devfs_destroy() are called from kern_conf.c and
* in both cases the devlock() mutex is held, so no further locking
* is necesary and no sleeping allowed.
*/
void
devfs_create(struct cdev *dev)
{
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
struct cdev_priv *cdp;
mtx_assert(&devmtx, MA_OWNED);
cdp = dev->si_priv;
cdp->cdp_flags |= CDP_ACTIVE;
cdp->cdp_inode = alloc_unrl(devfs_inos);
dev_refl(dev);
TAILQ_INSERT_TAIL(&cdevp_list, cdp, cdp_list);
devfs_generation++;
}
void
devfs_destroy(struct cdev *dev)
{
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
struct cdev_priv *cdp;
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
mtx_assert(&devmtx, MA_OWNED);
cdp = dev->si_priv;
cdp->cdp_flags &= ~CDP_ACTIVE;
devfs_generation++;
}
Rewamp DEVFS internals pretty severely [1]. Give DEVFS a proper inode called struct cdev_priv. It is important to keep in mind that this "inode" is shared between all DEVFS mountpoints, therefore it is protected by the global device mutex. Link the cdev_priv's into a list, protected by the global device mutex. Keep track of each cdev_priv's state with a flag bit and of references from mountpoints with a dedicated usecount. Reap the benefits of much improved kernel memory allocator and the generally better defined device driver APIs to get rid of the tables of pointers + serial numbers, their overflow tables, the atomics to muck about in them and all the trouble that resulted in. This makes RAM the only limit on how many devices we can have. The cdev_priv is actually a super struct containing the normal cdev as the "public" part, and therefore allocation and freeing has moved to devfs_devs.c from kern_conf.c. The overall responsibility is (to be) split such that kern/kern_conf.c is the stuff that deals with drivers and struct cdev and fs/devfs handles filesystems and struct cdev_priv and their private liason exposed only in devfs_int.h. Move the inode number from cdev to cdev_priv and allocate inode numbers properly with unr. Local dirents in the mountpoints (directories, symlinks) allocate inodes from the same pool to guarantee against overlaps. Various other fields are going to migrate from cdev to cdev_priv in the future in order to hide them. A few fields may migrate from devfs_dirent to cdev_priv as well. Protect the DEVFS mountpoint with an sx lock instead of lockmgr, this lock also protects the directory tree of the mountpoint. Give each mountpoint a unique integer index, allocated with unr. Use it into an array of devfs_dirent pointers in each cdev_priv. Initially the array points to a single element also inside cdev_priv, but as more devfs instances are mounted, the array is extended with malloc(9) as necessary when the filesystem populates its directory tree. Retire the cdev alias lists, the cdev_priv now know about all the relevant devfs_dirents (and their vnodes) and devfs_revoke() will pick them up from there. We still spelunk into other mountpoints and fondle their data without 100% good locking. It may make better sense to vector the revoke event into the tty code and there do a destroy_dev/make_dev on the tty's devices, but that's for further study. Lots of shuffling of stuff and churn of bits for no good reason[2]. XXX: There is still nothing preventing the dev_clone EVENTHANDLER from being invoked at the same time in two devfs mountpoints. It is not obvious what the best course of action is here. XXX: comment out an if statement that lost its body, until I can find out what should go there so it doesn't do damage in the meantime. XXX: Leave in a few extra malloc types and KASSERTS to help track down any remaining issues. Much testing provided by: Kris Much confusion caused by (races in): md(4) [1] You are not supposed to understand anything past this point. [2] This line should simplify life for the peanut gallery.
2005-09-19 19:56:48 +00:00
static void
devfs_devs_init(void *junk __unused)
{
devfs_inos = new_unrhdr(DEVFS_ROOTINO + 1, INT_MAX, &devmtx);
}
SYSINIT(devfs_devs, SI_SUB_DEVFS, SI_ORDER_FIRST, devfs_devs_init, NULL);