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216936ca6d
freebsd-skq/sys/miscfs/devfs/devfs_vnops.c
phk 216936ca6d Make bdev userland access work like cdev userland access unless 
the highly non-recommended option ALLOW_BDEV_ACCESS is used.

(bdev access is evil because you don't get write errors reported.)

Kill si_bsize_best before it kills Matt :-)

Use the specfs routines rather having cloned copies in devfs.
1999-08-30 07:56:23 +00:00

2072 lines
50 KiB
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/*
* Copyright 1997,1998 Julian Elischer. All rights reserved.
* julian@freebsd.org
*
* 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. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER ``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 HOLDER 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.
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/buf.h>
#include <sys/namei.h>
#include <sys/kernel.h>
#include <sys/fcntl.h>
#include <sys/conf.h>
#include <sys/disklabel.h>
#include <sys/lock.h>
#include <sys/stat.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/time.h>
#include <sys/vnode.h>
#include <sys/dirent.h>
#include <miscfs/devfs/devfsdefs.h>
#include <sys/vmmeter.h>
#include <vm/vm.h>
#include <vm/vm_prot.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <vm/vnode_pager.h>
#include <vm/vm_extern.h>
/*
* Insert description here
*/
/*
* Convert a component of a pathname into a pointer to a locked node.
* This is a very central and rather complicated routine.
* If the file system is not maintained in a strict tree hierarchy,
* this can result in a deadlock situation (see comments in code below).
*
* The flag argument is LOOKUP, CREATE, RENAME, or DELETE depending on
* whether the name is to be looked up, created, renamed, or deleted.
* When CREATE, RENAME, or DELETE is specified, information usable in
* creating, renaming, or deleting a directory entry may be calculated.
* If flag has LOCKPARENT or'ed into it and the target of the pathname
* exists, lookup returns both the target and its parent directory locked.
* When creating or renaming and LOCKPARENT is specified, the target may
* not be ".". When deleting and LOCKPARENT is specified, the target may
* be "."., but the caller must check to ensure it does an vrele and DNUNLOCK
* instead of two DNUNLOCKs.
*
* Overall outline of devfs_lookup:
*
* check accessibility of directory
* null terminate the component (lookup leaves the whole string alone)
* look for name in cache, if found, then if at end of path
* and deleting or creating, drop it, else return name
* search for name in directory, to found or notfound
* notfound:
* if creating, return locked directory,
* else return error
* found:
* if at end of path and deleting, return information to allow delete
* if at end of path and rewriting (RENAME and LOCKPARENT), lock target
* node and return info to allow rewrite
* if not at end, add name to cache; if at end and neither creating
* nor deleting, add name to cache
* On return to lookup, remove the null termination we put in at the start.
*
* NOTE: (LOOKUP | LOCKPARENT) currently returns the parent node unlocked.
*/
static int
devfs_lookup(struct vop_lookup_args *ap)
/*struct vop_lookup_args {
struct vnode * a_dvp; directory vnode ptr
struct vnode ** a_vpp; where to put the result
struct componentname * a_cnp; the name we want
};*/
{
struct componentname *cnp = ap->a_cnp;
struct vnode *dir_vnode = ap->a_dvp;
struct vnode **result_vnode = ap->a_vpp;
dn_p dir_node; /* the directory we are searching */
dn_p new_node; /* the node we are searching for */
devnm_p new_nodename;
int flags = cnp->cn_flags;
int op = cnp->cn_nameiop; /* LOOKUP, CREATE, RENAME, or DELETE */
int lockparent = flags & LOCKPARENT;
int wantparent = flags & (LOCKPARENT|WANTPARENT);
int error = 0;
struct proc *p = cnp->cn_proc;
char heldchar; /* the char at the end of the name componet */
*result_vnode = NULL; /* safe not sorry */ /*XXX*/
DBPRINT(("lookup\n"));
if (dir_vnode->v_usecount == 0)
printf("dir had no refs ");
if (devfs_vntodn(dir_vnode,&dir_node))
{
printf("vnode has changed?\n");
vprint("=",dir_vnode);
return(EINVAL);
}
/*
* Check accessiblity of directory.
*/
if (dir_node->type != DEV_DIR) /* XXX or symlink? */
{
return (ENOTDIR);
}
if ((error = VOP_ACCESS(dir_vnode, VEXEC, cnp->cn_cred, p)) != 0)
{
return (error);
}
/*
* We now have a segment name to search for, and a directory to search.
*
*/
/***********************************************************************\
* SEARCH FOR NAME *
* while making sure the component is null terminated for the strcmp *
\***********************************************************************/
heldchar = cnp->cn_nameptr[cnp->cn_namelen];
cnp->cn_nameptr[cnp->cn_namelen] = '\0';
new_nodename = dev_findname(dir_node,cnp->cn_nameptr);
cnp->cn_nameptr[cnp->cn_namelen] = heldchar;
if(!new_nodename) {
/*******************************************************\
* Failed to find it.. (That may be good) *
\*******************************************************/
new_node = NULL; /* to be safe */
/*
* If creating, and at end of pathname
* then can consider
* allowing file to be created.
*/
if (!(flags & ISLASTCN) || !(op == CREATE || op == RENAME)) {
return ENOENT;
}
/*
* Access for write is interpreted as allowing
* creation of files in the directory.
*/
if ((error = VOP_ACCESS(dir_vnode, VWRITE,
cnp->cn_cred, p)) != 0)
{
DBPRINT(("MKACCESS "));
return (error);
}
/*
* We return with the directory locked, so that
* the parameters we set up above will still be
* valid if we actually decide to add a new entry.
* We return ni_vp == NULL to indicate that the entry
* does not currently exist; we leave a pointer to
* the (locked) directory vnode in namei_data->ni_dvp.
* The pathname buffer is saved so that the name
* can be obtained later.
*
* NB - if the directory is unlocked, then this
* information cannot be used.
*/
cnp->cn_flags |= SAVENAME; /*XXX why? */
if (!lockparent)
VOP_UNLOCK(dir_vnode, 0, p);
return (EJUSTRETURN);
}
/***************************************************************\
* Found it.. this is not always a good thing.. *
\***************************************************************/
new_node = new_nodename->dnp;
new_node->last_lookup = new_nodename; /* for unlink */
/*
* If deleting, and at end of pathname, return
* parameters which can be used to remove file.
* If the wantparent flag isn't set, we return only
* the directory (in namei_data->ni_dvp), otherwise we go
* on and lock the node, being careful with ".".
*/
if (op == DELETE && (flags & ISLASTCN)) {
/*
* Write access to directory required to delete files.
*/
if ((error = VOP_ACCESS(dir_vnode, VWRITE,
cnp->cn_cred, p)) != 0)
return (error);
/*
* we are trying to delete '.'. What does this mean? XXX
*/
if (dir_node == new_node) {
VREF(dir_vnode);
*result_vnode = dir_vnode;
return (0);
}
/*
* If directory is "sticky", then user must own
* the directory, or the file in it, else she
* may not delete it (unless she's root). This
* implements append-only directories.
*/
devfs_dntovn(new_node,result_vnode);
#ifdef NOTYET
if ((dir_node->mode & ISVTX) &&
cnp->cn_cred->cr_uid != 0 &&
cnp->cn_cred->cr_uid != dir_node->uid &&
cnp->cn_cred->cr_uid != new_node->uid) {
VOP_UNLOCK(*result_vnode, 0, p);
return (EPERM);
}
#endif
if (!lockparent)
VOP_UNLOCK(dir_vnode, 0, p);
return (0);
}
/*
* If rewriting (RENAME), return the vnode and the
* information required to rewrite the present directory
* Must get node of directory entry to verify it's a
* regular file, or empty directory.
*/
if (op == RENAME && wantparent && (flags & ISLASTCN)) {
/*
* Are we allowed to change the holding directory?
*/
if ((error = VOP_ACCESS(dir_vnode, VWRITE,
cnp->cn_cred, p)) != 0)
return (error);
/*
* Careful about locking second node.
* This can only occur if the target is ".".
*/
if (dir_node == new_node)
return (EISDIR);
devfs_dntovn(new_node,result_vnode);
/* hmm save the 'from' name (we need to delete it) */
cnp->cn_flags |= SAVENAME;
if (!lockparent)
VOP_UNLOCK(dir_vnode, 0, p);
return (0);
}
/*
* Step through the translation in the name. We do not unlock the
* directory because we may need it again if a symbolic link
* is relative to the current directory. Instead we save it
* unlocked as "saved_dir_node" XXX. We must get the target
* node before unlocking
* the directory to insure that the node will not be removed
* before we get it. We prevent deadlock by always fetching
* nodes from the root, moving down the directory tree. Thus
* when following backward pointers ".." we must unlock the
* parent directory before getting the requested directory.
* There is a potential race condition here if both the current
* and parent directories are removed before the lock for the
* node associated with ".." returns. We hope that this occurs
* infrequently since we cannot avoid this race condition without
* implementing a sophisticated deadlock detection algorithm.
* Note also that this simple deadlock detection scheme will not
* work if the file system has any hard links other than ".."
* that point backwards in the directory structure.
*/
if (flags & ISDOTDOT) {
VOP_UNLOCK(dir_vnode, 0, p); /* race to get the node */
devfs_dntovn(new_node,result_vnode);
if (lockparent && (flags & ISLASTCN))
vn_lock(dir_vnode, LK_EXCLUSIVE | LK_RETRY, p);
} else if (dir_node == new_node) {
VREF(dir_vnode); /* we want ourself, ie "." */
*result_vnode = dir_vnode;
} else {
devfs_dntovn(new_node,result_vnode);
if (!lockparent || (flags & ISLASTCN))
VOP_UNLOCK(dir_vnode, 0, p);
}
DBPRINT(("GOT\n"));
return (0);
}
/*
*/
static int
devfs_access(struct vop_access_args *ap)
/*struct vop_access_args {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */
{
/*
* mode is filled with a combination of VREAD, VWRITE,
* and/or VEXEC bits turned on. In an octal number these
* are the Y in 0Y00.
*/
struct vnode *vp = ap->a_vp;
int mode = ap->a_mode;
struct ucred *cred = ap->a_cred;
dn_p dnp;
int error;
gid_t *gp;
int i;
DBPRINT(("access\n"));
if ((error = devfs_vntodn(vp,&dnp)) != 0)
{
printf("devfs_vntodn returned %d ",error);
return error;
}
/*
* if we are not running as a process, we are in the
* kernel and we DO have permission
*/
if (ap->a_p == NULL)
return 0;
/*
* Access check is based on only one of owner, group, public.
* If not owner, then check group. If not a member of the
* group, then check public access.
*/
if (cred->cr_uid != dnp->uid)
{
/* failing that.. try groups */
mode >>= 3;
gp = cred->cr_groups;
for (i = 0; i < cred->cr_ngroups; i++, gp++)
{
if (dnp->gid == *gp)
{
goto found;
}
}
/* failing that.. try general access */
mode >>= 3;
found:
;
}
if ((dnp->mode & mode) == mode)
return (0);
/*
* Root gets to do anything.
* but only use suser_xxx prives as a last resort
* (Use of super powers is recorded in ap->a_p->p_acflag)
*/
if( suser_xxx(cred, ap->a_p, 0) == 0) /* XXX what if no proc? */
return 0;
return (EACCES);
}
static int
devfs_getattr(struct vop_getattr_args *ap)
/*struct vop_getattr_args {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */
{
struct vnode *vp = ap->a_vp;
struct vattr *vap = ap->a_vap;
dn_p dnp;
int error;
DBPRINT(("getattr\n"));
if ((error = devfs_vntodn(vp,&dnp)) != 0)
{
printf("devfs_vntodn returned %d ",error);
return error;
}
vap->va_rdev = 0;/* default value only */
vap->va_mode = dnp->mode;
switch (dnp->type)
{
case DEV_DIR:
vap->va_rdev = (udev_t)dnp->dvm;
vap->va_mode |= (S_IFDIR);
break;
case DEV_CDEV:
vap->va_rdev = dev2udev(vp->v_rdev);
vap->va_mode |= (S_IFCHR);
break;
case DEV_BDEV:
vap->va_rdev = dev2budev(vp->v_rdev);
vap->va_mode |= (S_IFBLK);
break;
case DEV_SLNK:
break;
}
vap->va_type = vp->v_type;
vap->va_nlink = dnp->links;
vap->va_uid = dnp->uid;
vap->va_gid = dnp->gid;
vap->va_fsid = (intptr_t)(void *)dnp->dvm;
vap->va_fileid = (intptr_t)(void *)dnp;
vap->va_size = dnp->len; /* now a u_quad_t */
vap->va_blocksize = 512;
/*
* XXX If the node times are in Jan 1, 1970, then
* update them to the boot time.
* When we made the node, the date/time was not yet known.
*/
if(dnp->ctime.tv_sec < (24 * 3600))
{
TIMEVAL_TO_TIMESPEC(&boottime,&(dnp->ctime));
TIMEVAL_TO_TIMESPEC(&boottime,&(dnp->mtime));
TIMEVAL_TO_TIMESPEC(&boottime,&(dnp->atime));
}
if (dnp->flags & IN_ACCESS) {
nanotime(&dnp->atime);
dnp->flags &= ~IN_ACCESS;
}
vap->va_ctime = dnp->ctime;
vap->va_mtime = dnp->mtime;
vap->va_atime = dnp->atime;
vap->va_gen = 0;
vap->va_flags = 0;
vap->va_bytes = dnp->len; /* u_quad_t */
vap->va_filerev = 0; /* XXX */ /* u_quad_t */
vap->va_vaflags = 0; /* XXX */
return 0;
}
static int
devfs_setattr(struct vop_setattr_args *ap)
/*struct vop_setattr_args {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */
{
struct vnode *vp = ap->a_vp;
struct vattr *vap = ap->a_vap;
struct ucred *cred = ap->a_cred;
struct proc *p = ap->a_p;
int error = 0;
gid_t *gp;
int i;
dn_p dnp;
if (vap->va_flags != VNOVAL) /* XXX needs to be implemented */
return (EOPNOTSUPP);
if ((error = devfs_vntodn(vp,&dnp)) != 0)
{
printf("devfs_vntodn returned %d ",error);
return error;
}
DBPRINT(("setattr\n"));
if ((vap->va_type != VNON) ||
(vap->va_nlink != VNOVAL) ||
(vap->va_fsid != VNOVAL) ||
(vap->va_fileid != VNOVAL) ||
(vap->va_blocksize != VNOVAL) ||
(vap->va_rdev != VNOVAL) ||
(vap->va_bytes != VNOVAL) ||
(vap->va_gen != VNOVAL ))
{
return EINVAL;
}
/*
* Anyone can touch the files in such a way that the times are set
* to NOW (e.g. run 'touch') if they have write permissions
* however only the owner or root can set "un-natural times.
* They also don't need write permissions.
*/
if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
#if 0 /*
* This next test is pointless under devfs for now..
* as there is only one devfs hiding under potentially many
* mountpoints and actual device node are really 'mounted' under
* a FAKE mountpoint inside the kernel only, no matter where it
* APPEARS they are mounted to the outside world..
* A readonly devfs doesn't exist anyway.
*/
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return (EROFS);
#endif
if (((vap->va_vaflags & VA_UTIMES_NULL) == 0) &&
(cred->cr_uid != dnp->uid) &&
suser_xxx(cred, p, 0))
return (EPERM);
if(VOP_ACCESS(vp, VWRITE, cred, p))
return (EACCES);
dnp->atime = vap->va_atime;
dnp->mtime = vap->va_mtime;
nanotime(&dnp->ctime);
return (0);
}
/*
* Change the permissions.. must be root or owner to do this.
*/
if (vap->va_mode != (u_short)VNOVAL) {
if ((cred->cr_uid != dnp->uid)
&& suser_xxx(cred, p, 0))
return (EPERM);
/* set drwxwxrwx stuff */
dnp->mode &= ~07777;
dnp->mode |= vap->va_mode & 07777;
}
/*
* Change the owner.. must be root to do this.
*/
if (vap->va_uid != (uid_t)VNOVAL) {
if (suser_xxx(cred, p, 0))
return (EPERM);
dnp->uid = vap->va_uid;
}
/*
* Change the group.. must be root or owner to do this.
* If we are the owner, we must be in the target group too.
* don't use suser_xxx() unless you have to as it reports
* whether you needed suser_xxx powers or not.
*/
if (vap->va_gid != (gid_t)VNOVAL) {
if (cred->cr_uid == dnp->uid){
gp = cred->cr_groups;
for (i = 0; i < cred->cr_ngroups; i++, gp++) {
if (vap->va_gid == *gp)
goto cando;
}
}
/*
* we can't do it with normal privs,
* do we have an ace up our sleeve?
*/
if( suser_xxx(cred, p, 0))
return (EPERM);
cando:
dnp->gid = vap->va_gid;
}
#if 0
/*
* Copied from somewhere else
* but only kept as a marker and reminder of the fact that
* flags should be handled some day
*/
if (vap->va_flags != VNOVAL) {
if (error = suser_xxx(cred, p, 0))
return error;
if (cred->cr_uid == 0)
;
else {
}
}
#endif
return error;
}
static int
devfs_xread(struct vop_read_args *ap)
/*struct vop_read_args {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */
{
int error = 0;
dn_p dnp;
struct vnode *vp = ap->a_vp;
DBPRINT(("read\n"));
if ((error = devfs_vntodn(vp,&dnp)) != 0)
{
printf("devfs_vntodn returned %d ",error);
return error;
}
switch (vp->v_type) {
case VREG:
return(EINVAL);
case VDIR:
return VOP_READDIR(vp,ap->a_uio,ap->a_cred,
NULL,NULL,NULL);
case VCHR:
case VBLK:
panic("devfs: vnode methods");
default:
panic("devfs_read(): bad file type");
break;
}
}
/*
* Write data to a file or directory.
*/
static int
devfs_xwrite(struct vop_write_args *ap)
/*struct vop_write_args {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */
{
struct vnode *vp = ap->a_vp;
switch (vp->v_type) {
case VREG:
return(EINVAL);
case VDIR:
return(EISDIR);
case VCHR:
case VBLK:
panic("devfs: vnode methods");
default:
panic("devfs_xwrite(): bad file type");
}
}
static int
devfs_remove(struct vop_remove_args *ap)
/*struct vop_remove_args {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */
{
struct vnode *vp = ap->a_vp;
struct vnode *dvp = ap->a_dvp;
struct componentname *cnp = ap->a_cnp;
dn_p tp, tdp;
devnm_p tnp;
int doingdirectory = 0;
int error = 0;
uid_t ouruid = cnp->cn_cred->cr_uid;
DBPRINT(("remove\n"));
/*
* Lock our directories and get our name pointers
* assume that the names are null terminated as they
* are the end of the path. Get pointers to all our
* devfs structures.
*/
if ((error = devfs_vntodn(dvp, &tdp)) != 0) {
abortit:
VOP_ABORTOP(dvp, cnp);
return (error);
}
if ((error = devfs_vntodn(vp, &tp)) != 0) goto abortit;
/*
* Assuming we are atomic, dev_lookup left this for us
*/
tnp = tp->last_lookup;
/*
* Check we are doing legal things WRT the new flags
*/
if ((tp->flags & (IMMUTABLE | APPEND))
|| (tdp->flags & APPEND) /*XXX eh?*/ ) {
error = EPERM;
goto abortit;
}
/*
* Make sure that we don't try do something stupid
*/
if ((tp->type) == DEV_DIR) {
/*
* Avoid ".", "..", and aliases of "." for obvious reasons.
*/
if ( (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.')
|| (cnp->cn_flags&ISDOTDOT) ) {
error = EINVAL;
goto abortit;
}
doingdirectory++;
}
/***********************************
* Start actually doing things.... *
***********************************/
getnanotime(&(tdp->mtime));
/*
* own the parent directory, or the destination of the rename,
* otherwise the destination may not be changed (except by
* root). This implements append-only directories.
* XXX shoudn't this be in generic code?
*/
if ((tdp->mode & S_ISTXT)
&& ouruid != 0
&& ouruid != tdp->uid
&& ouruid != tp->uid ) {
error = EPERM;
goto abortit;
}
/*
* Target must be empty if a directory and have no links
* to it. Also, ensure source and target are compatible
* (both directories, or both not directories).
*/
if (( doingdirectory) && (tp->links > 2)) {
printf("nlink = %d\n",tp->links); /*XXX*/
error = ENOTEMPTY;
goto abortit;
}
dev_free_name(tnp);
tp = NULL;
return (error);
}
/*
*/
static int
devfs_link(struct vop_link_args *ap)
/*struct vop_link_args {
struct vnode *a_tdvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */
{
struct vnode *vp = ap->a_vp;
struct vnode *tdvp = ap->a_tdvp;
struct componentname *cnp = ap->a_cnp;
dn_p fp, tdp;
devnm_p tnp;
int error = 0;
DBPRINT(("link\n"));
/*
* First catch an arbitrary restriction for this FS
*/
if(cnp->cn_namelen > DEVMAXNAMESIZE) {
error = ENAMETOOLONG;
goto abortit;
}
/*
* Lock our directories and get our name pointers
* assume that the names are null terminated as they
* are the end of the path. Get pointers to all our
* devfs structures.
*/
if ((error = devfs_vntodn(tdvp,&tdp)) != 0) goto abortit;
if ((error = devfs_vntodn(vp,&fp)) != 0) goto abortit;
/*
* trying to move it out of devfs? (v_tag == VT_DEVFS)
*/
if ( (vp->v_tag != VT_DEVFS)
|| (vp->v_tag != tdvp->v_tag) ) {
error = EXDEV;
abortit:
VOP_ABORTOP(tdvp, cnp);
goto out;
}
/*
* Check we are doing legal things WRT the new flags
*/
if (fp->flags & (IMMUTABLE | APPEND)) {
error = EPERM;
goto abortit;
}
/***********************************
* Start actually doing things.... *
***********************************/
getnanotime(&(tdp->atime));
error = dev_add_name(cnp->cn_nameptr,
tdp,
NULL,
fp,
&tnp);
out:
return (error);
}
/*
* Rename system call. Seems overly complicated to me...
* rename("foo", "bar");
* is essentially
* unlink("bar");
* link("foo", "bar");
* unlink("foo");
* but ``atomically''.
*
* When the target exists, both the directory
* and target vnodes are locked.
* the source and source-parent vnodes are referenced
*
*
* Basic algorithm is:
*
* 1) Bump link count on source while we're linking it to the
* target. This also ensure the inode won't be deleted out
* from underneath us while we work (it may be truncated by
* a concurrent `trunc' or `open' for creation).
* 2) Link source to destination. If destination already exists,
* delete it first.
* 3) Unlink source reference to node if still around. If a
* directory was moved and the parent of the destination
* is different from the source, patch the ".." entry in the
* directory.
*/
static int
devfs_rename(struct vop_rename_args *ap)
/*struct vop_rename_args {
struct vnode *a_fdvp;
struct vnode *a_fvp;
struct componentname *a_fcnp;
struct vnode *a_tdvp;
struct vnode *a_tvp;
struct componentname *a_tcnp;
} */
{
struct vnode *tvp = ap->a_tvp;
struct vnode *tdvp = ap->a_tdvp;
struct vnode *fvp = ap->a_fvp;
struct vnode *fdvp = ap->a_fdvp;
struct componentname *tcnp = ap->a_tcnp;
struct componentname *fcnp = ap->a_fcnp;
struct proc *p = fcnp->cn_proc;
dn_p fp, fdp, tp, tdp;
devnm_p fnp,tnp;
int doingdirectory = 0;
int error = 0;
/*
* First catch an arbitrary restriction for this FS
*/
if(tcnp->cn_namelen > DEVMAXNAMESIZE) {
error = ENAMETOOLONG;
goto abortit;
}
/*
* Lock our directories and get our name pointers
* assume that the names are null terminated as they
* are the end of the path. Get pointers to all our
* devfs structures.
*/
if ((error = devfs_vntodn(tdvp,&tdp)) != 0) goto abortit;
if ((error = devfs_vntodn(fdvp,&fdp)) != 0) goto abortit;
if ((error = devfs_vntodn(fvp,&fp)) != 0) goto abortit;
fnp = fp->last_lookup;
if (tvp) {
if ((error = devfs_vntodn(tvp,&tp)) != 0) goto abortit;
tnp = tp->last_lookup;
} else {
tp = NULL;
tnp = NULL;
}
/*
* trying to move it out of devfs? (v_tag == VT_DEVFS)
* if we move a dir across mnt points. we need to fix all
* the mountpoint pointers! XXX
* so for now keep dirs within the same mount
*/
if ( (fvp->v_tag != VT_DEVFS)
|| (fvp->v_tag != tdvp->v_tag)
|| (tvp && (fvp->v_tag != tvp->v_tag))
|| ((fp->type == DEV_DIR) && (fp->dvm != tdp->dvm ))) {
error = EXDEV;
abortit:
VOP_ABORTOP(tdvp, tcnp);
if (tdvp == tvp) /* eh? */
vrele(tdvp);
else
vput(tdvp);
if (tvp)
vput(tvp);
VOP_ABORTOP(fdvp, fcnp); /* XXX, why not in NFS? */
vrele(fdvp);
vrele(fvp);
return (error);
}
/*
* Check we are doing legal things WRT the new flags
*/
if ((tp && (tp->flags & (IMMUTABLE | APPEND)))
|| (fp->flags & (IMMUTABLE | APPEND))
|| (fdp->flags & APPEND)) {
error = EPERM;
goto abortit;
}
/*
* Make sure that we don't try do something stupid
*/
if ((fp->type) == DEV_DIR) {
/*
* Avoid ".", "..", and aliases of "." for obvious reasons.
*/
if ((fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.')
|| (fcnp->cn_flags&ISDOTDOT)
|| (tcnp->cn_namelen == 1 && tcnp->cn_nameptr[0] == '.')
|| (tcnp->cn_flags&ISDOTDOT)
|| (tdp == fp )) {
error = EINVAL;
goto abortit;
}
doingdirectory++;
}
/*
* If ".." must be changed (ie the directory gets a new
* parent) then the source directory must not be in the
* directory heirarchy above the target, as this would
* orphan everything below the source directory. Also
* the user must have write permission in the source so
* as to be able to change "..".
*/
if (doingdirectory && (tdp != fdp)) {
dn_p tmp,ntmp;
error = VOP_ACCESS(fvp, VWRITE, tcnp->cn_cred, tcnp->cn_proc);
tmp = tdp;
do {
if(tmp == fp) {
/* XXX unlock stuff here probably */
error = EINVAL;
goto out;
}
ntmp = tmp;
} while ((tmp = tmp->by.Dir.parent) != ntmp);
}
/***********************************
* Start actually doing things.... *
***********************************/
getnanotime(&(fp->atime));
/*
* Check if just deleting a link name.
*/
if (fvp == tvp) {
if (fvp->v_type == VDIR) {
error = EINVAL;
goto abortit;
}
/* Release destination completely. */
VOP_ABORTOP(tdvp, tcnp);
vput(tdvp);
vput(tvp);
/* Delete source. */
VOP_ABORTOP(fdvp, fcnp); /*XXX*/
vrele(fdvp);
vrele(fvp);
dev_free_name(fnp);
return 0;
}
/*
* 1) Bump link count while we're moving stuff
* around. If we crash somewhere before
* completing our work, too bad :)
*/
fp->links++;
/*
* If the target exists zap it (unless it's a non-empty directory)
* We could do that as well but won't
*/
if (tp) {
int ouruid = tcnp->cn_cred->cr_uid;
/*
* If the parent directory is "sticky", then the user must
* own the parent directory, or the destination of the rename,
* otherwise the destination may not be changed (except by
* root). This implements append-only directories.
* XXX shoudn't this be in generic code?
*/
if ((tdp->mode & S_ISTXT)
&& ouruid != 0
&& ouruid != tdp->uid
&& ouruid != tp->uid ) {
error = EPERM;
goto bad;
}
/*
* Target must be empty if a directory and have no links
* to it. Also, ensure source and target are compatible
* (both directories, or both not directories).
*/
if (( doingdirectory) && (tp->links > 2)) {
printf("nlink = %d\n",tp->links); /*XXX*/
error = ENOTEMPTY;
goto bad;
}
dev_free_name(tnp);
tp = NULL;
}
dev_add_name(tcnp->cn_nameptr,tdp,fnp->as.front.realthing,fp,&tnp);
fnp->dnp = NULL;
fp->links--; /* one less link to it.. */
dev_free_name(fnp);
fp->links--; /* we added one earlier*/
if (tdp)
vput(tdvp);
if (tp)
vput(fvp);
vrele(ap->a_fvp);
return (error);
bad:
if (tp)
vput(tvp);
vput(tdvp);
out:
if (vn_lock(fvp, LK_EXCLUSIVE | LK_RETRY, p) == 0) {
fp->links--; /* we added one earlier*/
vput(fvp);
} else
vrele(fvp);
return (error);
}
static int
devfs_symlink(struct vop_symlink_args *ap)
/*struct vop_symlink_args {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
char *a_target;
} */
{
struct vnode *vp;
int error;
dn_p dnp;
union typeinfo by;
devnm_p nm_p;
DBPRINT(("symlink\n"));
if((error = devfs_vntodn(ap->a_dvp, &dnp)) != 0) {
return (error);
}
by.Slnk.name = ap->a_target;
by.Slnk.namelen = strlen(ap->a_target);
dev_add_entry(ap->a_cnp->cn_nameptr, dnp, DEV_SLNK, &by,
NULL, NULL, &nm_p);
if((error = devfs_dntovn(nm_p->dnp, &vp)) != 0) {
return (error);
}
VOP_SETATTR(vp, ap->a_vap, ap->a_cnp->cn_cred, ap->a_cnp->cn_proc);
*ap->a_vpp = NULL;
vput(vp);
return 0;
}
/*
* Vnode op for readdir
*/
static int
devfs_readdir(struct vop_readdir_args *ap)
/*struct vop_readdir_args {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
int *eofflag;
int *ncookies;
u_int **cookies;
} */
{
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct dirent dirent;
dn_p dir_node;
devnm_p name_node;
char *name;
int error = 0;
int reclen;
int nodenumber;
int startpos,pos;
DBPRINT(("readdir\n"));
/* set up refs to dir */
if ((error = devfs_vntodn(vp,&dir_node)) != 0)
return error;
if(dir_node->type != DEV_DIR)
return(ENOTDIR);
pos = 0;
startpos = uio->uio_offset;
name_node = dir_node->by.Dir.dirlist;
nodenumber = 0;
getnanotime(&(dir_node->atime));
while ((name_node || (nodenumber < 2)) && (uio->uio_resid > 0))
{
switch(nodenumber)
{
case 0:
dirent.d_fileno = (uintptr_t)(void *)dir_node;
name = ".";
dirent.d_namlen = 1;
dirent.d_type = DT_DIR;
break;
case 1:
if(dir_node->by.Dir.parent)
dirent.d_fileno
= (uintptr_t)(void *)dir_node->by.Dir.parent;
else
dirent.d_fileno = (uintptr_t)(void *)dir_node;
name = "..";
dirent.d_namlen = 2;
dirent.d_type = DT_DIR;
break;
default:
dirent.d_fileno = (uintptr_t)(void *)name_node->dnp;
dirent.d_namlen = strlen(name_node->name);
name = name_node->name;
switch(name_node->dnp->type) {
case DEV_BDEV:
dirent.d_type = DT_BLK;
break;
case DEV_CDEV:
dirent.d_type = DT_CHR;
break;
case DEV_DDEV:
dirent.d_type = DT_SOCK; /*XXX*/
break;
case DEV_DIR:
dirent.d_type = DT_DIR;
break;
case DEV_SLNK:
dirent.d_type = DT_LNK;
break;
default:
dirent.d_type = DT_UNKNOWN;
}
}
reclen = dirent.d_reclen = GENERIC_DIRSIZ(&dirent);
if(pos >= startpos) /* made it to the offset yet? */
{
if (uio->uio_resid < reclen) /* will it fit? */
break;
strcpy( dirent.d_name,name);
if ((error = uiomove ((caddr_t)&dirent,
dirent.d_reclen, uio)) != 0)
break;
}
pos += reclen;
if((nodenumber >1) && name_node)
name_node = name_node->next;
nodenumber++;
}
uio->uio_offset = pos;
return (error);
}
/*
*/
static int
devfs_readlink(struct vop_readlink_args *ap)
/*struct vop_readlink_args {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
} */
{
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
dn_p lnk_node;
int error = 0;
DBPRINT(("readlink\n"));
/* set up refs to dir */
if ((error = devfs_vntodn(vp,&lnk_node)) != 0)
return error;
if(lnk_node->type != DEV_SLNK)
return(EINVAL);
if ((error = VOP_ACCESS(vp, VREAD, ap->a_cred, NULL)) != 0) { /* XXX */
return error;
}
error = uiomove(lnk_node->by.Slnk.name, lnk_node->by.Slnk.namelen, uio);
return error;
}
#ifdef notyet
static int
devfs_abortop(struct vop_abortop_args *ap)
/*struct vop_abortop_args {
struct vnode *a_dvp;
struct componentname *a_cnp;
} */
{
DBPRINT(("abortop\n"));
if ((ap->a_cnp->cn_flags & (HASBUF | SAVESTART)) == HASBUF)
zfree(namei_zone, ap->a_cnp->cn_pnbuf);
return 0;
}
#endif /* notyet */
static int
devfs_reclaim(struct vop_reclaim_args *ap)
/*struct vop_reclaim_args {
struct vnode *a_vp;
} */
{
dn_p dnp = NULL;
int error;
struct vnode *vp = ap->a_vp;
DBPRINT(("reclaim\n"));
if ((error = devfs_vntodn(vp,&dnp)) != 0)
{
printf("devfs_vntodn returned %d ",error);
return error;
}
vp->v_data = NULL;
if (dnp) {
dnp->vn = 0;
dnp->vn_id = 0;
}
return(0);
}
/*
* Print out the contents of a /devfs vnode.
*/
static int
devfs_print(struct vop_print_args *ap)
/*struct vop_print_args {
struct vnode *a_vp;
} */
{
printf("tag VT_DEVFS, devfs vnode\n");
return (0);
}
/**************************************************************************\
* pseudo ops *
\**************************************************************************/
/*proto*/
void
devfs_dropvnode(dn_p dnp)
{
struct vnode *vn_p;
#ifdef PARANOID
if(!dnp)
{
printf("devfs: dn count dropped too early\n");
}
#endif
vn_p = dnp->vn;
/*
* check if we have a vnode.......
*/
if((vn_p) && ( dnp->vn_id == vn_p->v_id) && (dnp == (dn_p)vn_p->v_data))
{
VOP_REVOKE(vn_p, REVOKEALL);
}
dnp->vn = NULL; /* be pedantic about this */
}
/* struct vnode *speclisth[SPECHSZ];*/ /* till specfs goes away */
/*
* Open a special file.
struct vop_open_args {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} *ap;
*/
/* ARGSUSED */
static int
devfs_open( struct vop_open_args *ap)
{
struct proc *p = ap->a_p;
struct vnode *vp = ap->a_vp;
int error;
dn_p dnp;
struct cdevsw *dsw;
dev_t bdev, dev = vp->v_rdev;
struct vnode *bvp;
if ((error = devfs_vntodn(vp,&dnp)) != 0)
return error;
switch (vp->v_type) {
case VCHR:
dsw = devsw(dev);
if ( (dsw == NULL) || (dsw->d_open == NULL))
return ENXIO;
if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) {
/*
* When running in very secure mode, do not allow
* opens for writing of any disk character devices.
*/
if (securelevel >= 2
&& dsw->d_bmaj != -1
&& (dsw->d_flags & D_TYPEMASK) == D_DISK)
return (EPERM);
/*
* When running in secure mode, do not allow opens
* for writing of /dev/mem, /dev/kmem, or character
* devices whose corresponding block devices are
* currently mounted.
*/
if (securelevel >= 1) {
if ((bdev = chrtoblk(dev)) != NODEV &&
vfinddev(bdev, VBLK, &bvp) &&
bvp->v_usecount > 0 &&
(error = vfs_mountedon(bvp)))
return (error);
if (iskmemdev(dev))
return (EPERM);
}
}
if ((dsw->d_flags & D_TYPEMASK) == D_TTY)
vp->v_flag |= VISTTY;
VOP_UNLOCK(vp, 0, p);
error = (*vp->v_rdev->si_devsw->d_open)(
vp->v_rdev,
ap->a_mode,
S_IFCHR,
p);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
return (error);
/* NOT REACHED */
case VBLK:
dsw = devsw(dev);
if ( (dsw == NULL) || (dsw->d_open == NULL))
return ENXIO;
/*
* When running in very secure mode, do not allow
* opens for writing of any disk block devices.
*/
if (securelevel >= 2 && ap->a_cred != FSCRED &&
(ap->a_mode & FWRITE) &&
(dsw->d_flags & D_TYPEMASK) == D_DISK)
return (EPERM);
/*
* Do not allow opens of block devices that are
* currently mounted.
*/
error = vfs_mountedon(vp);
if (error)
return (error);
error = (*vp->v_rdev->si_devsw->d_open)(
vp->v_rdev,
ap->a_mode,
S_IFBLK,
p);
break;
default:
break;
}
return (error);
}
/* ARGSUSED */
static int
devfs_read( struct vop_read_args *ap)
{
int error;
error = VOCALL(spec_vnodeop_p, VOFFSET(vop_read), ap);
return (error);
}
/* ARGSUSED */
static int
devfs_write( struct vop_write_args *ap)
{
int error;
error = VOCALL(spec_vnodeop_p, VOFFSET(vop_write), ap);
return (error);
}
/*
* Device ioctl operation.
struct vop_ioctl_args {
struct vnode *a_vp;
int a_command;
caddr_t a_data;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
}
*/
/* ARGSUSED */
static int
devfs_ioctl(struct vop_ioctl_args *ap)
{
dn_p dnp;
int error;
struct vnode *vp = ap->a_vp;
if ((error = devfs_vntodn(vp,&dnp)) != 0)
return error;
switch (vp->v_type) {
case VCHR:
return ((*vp->v_rdev->si_devsw->d_ioctl)(vp->v_rdev,
ap->a_command,
ap->a_data,
ap->a_fflag,
ap->a_p));
case VBLK:
return ((*vp->v_rdev->si_devsw->d_ioctl)(vp->v_rdev,
ap->a_command,
ap->a_data,
ap->a_fflag,
ap->a_p));
default:
panic("devfs_ioctl");
/* NOTREACHED */
}
}
/*
struct vop_poll_args {
struct vnode *a_vp;
int a_events;
struct ucred *a_cred;
struct proc *a_p;
} *ap;
*/
/* ARGSUSED */
static int
devfs_poll(struct vop_poll_args *ap)
{
dn_p dnp;
int error;
struct vnode *vp = ap->a_vp;
if ((error = devfs_vntodn(vp,&dnp)) != 0)
return error;
switch (vp->v_type) {
case VCHR:
return (*vp->v_rdev->si_devsw->d_poll)(vp->v_rdev,
ap->a_events,
ap->a_p);
default:
return (vop_defaultop((struct vop_generic_args *)ap));
}
}
/*
* Synch buffers associated with a block device
struct vop_fsync_args {
struct vnode *a_vp;
struct ucred *a_cred;
int a_waitfor;
struct proc *a_p;
}
*/
/* ARGSUSED */
static int
devfs_fsync(struct vop_fsync_args *ap)
{
struct vnode *vp = ap->a_vp;
struct buf *bp;
struct buf *nbp;
int s;
dn_p dnp;
int error;
if ((error = devfs_vntodn(vp,&dnp)) != 0)
return error;
if (vp->v_type == VCHR)
return (0);
/*
* Flush all dirty buffers associated with a block device.
*/
loop:
s = splbio();
for (bp = TAILQ_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
nbp = TAILQ_NEXT(bp, b_vnbufs);
if (BUF_LOCK(bp, LK_EXCLUSIVE | LK_NOWAIT))
continue;
if ((bp->b_flags & B_DELWRI) == 0)
panic("devfs_fsync: not dirty");
if ((vp->v_flag & VOBJBUF) && (bp->b_flags & B_CLUSTEROK)) {
BUF_UNLOCK(bp);
vfs_bio_awrite(bp);
splx(s);
} else {
bremfree(bp);
splx(s);
bawrite(bp);
}
goto loop;
}
if (ap->a_waitfor == MNT_WAIT) {
while (vp->v_numoutput) {
vp->v_flag |= VBWAIT;
(void) tsleep((caddr_t)&vp->v_numoutput, PRIBIO + 1, "spfsyn", 0);
}
#ifdef DIAGNOSTIC
if (!TAILQ_EMPTY(&vp->v_dirtyblkhd)) {
vprint("devfs_fsync: dirty", vp);
splx(s);
goto loop;
}
#endif
}
splx(s);
return (0);
}
/*
*
* struct vop_inactive_args {
* struct vnode *a_vp;
* struct proc *a_p;
* }
*/
static int
devfs_inactive(struct vop_inactive_args *ap)
{
VOP_UNLOCK(ap->a_vp, 0, ap->a_p);
return (0);
}
/*
* Just call the device strategy routine
struct vop_strategy_args {
struct vnode *a_vp;
struct buf *a_bp;
}
*/
static int
devfs_strategy(struct vop_strategy_args *ap)
{
struct buf *bp = ap->a_bp;
dn_p dnp;
int error;
struct vnode *vp = ap->a_vp;
if ((vp->v_type != VCHR)
&& (vp->v_type != VBLK))
panic ("devfs_strat:badvnode type");
if ((error = devfs_vntodn(vp,&dnp)) != 0)
return error;
if (((bp->b_flags & B_READ) == 0) &&
(LIST_FIRST(&bp->b_dep)) != NULL && bioops.io_start)
(*bioops.io_start)(bp);
switch (vp->v_type) {
case VCHR:
(*vp->v_rdev->si_devsw->d_strategy)(bp);
break;
case VBLK:
(*vp->v_rdev->si_devsw->d_strategy)(bp);
break;
default:
/* XXX set error code? */
break;
}
return (0);
}
/*
* I can't say I'm completely sure what this one is for.
* it's copied from specfs.
struct vop_freeblks_args {
struct vnode *a_vp;
daddr_t a_addr;
daddr_t a_length;
};
*/
static int
devfs_freeblks(struct vop_freeblks_args *ap)
{
struct cdevsw *bsw;
struct buf *bp;
struct vnode *vp = ap->a_vp;
bsw = devsw(vp->v_rdev);
if ((bsw->d_flags & D_CANFREE) == 0)
return (0);
bp = geteblk(ap->a_length);
bp->b_flags |= B_FREEBUF;
bp->b_dev = vp->v_rdev;
bp->b_blkno = ap->a_addr;
bp->b_offset = dbtob(ap->a_addr);
bp->b_bcount = ap->a_length;
BUF_STRATEGY(bp, 0);
return (0);
}
/*
* This is a noop, simply returning what one has been given.
struct vop_bmap_args {
struct vnode *a_vp;
daddr_t a_bn;
struct vnode **a_vpp;
daddr_t *a_bnp;
int *a_runp;
int *a_runb;
}
*/
static int
devfs_bmap(struct vop_bmap_args *ap)
{
if (ap->a_vpp != NULL)
*ap->a_vpp = ap->a_vp;
if (ap->a_bnp != NULL)
*ap->a_bnp = ap->a_bn;
if (ap->a_runp != NULL)
*ap->a_runp = 0;
if (ap->a_runb != NULL)
*ap->a_runb = 0;
return (0);
}
/*
* Device close routine
struct vop_close_args {
struct vnode *a_vp;
int a_fflag;
struct ucred *a_cred;
struct proc *a_p;
}
*/
/* ARGSUSED */
static int
devfs_close(struct vop_close_args *ap)
{
struct vnode *vp = ap->a_vp;
dn_p dnp;
struct cdevsw *devswp;
dev_t dev;
int mode, error;
if ((error = devfs_vntodn(vp,&dnp)) != 0)
return error;
switch (vp->v_type) {
case VCHR:
devswp = vp->v_rdev->si_devsw;
dev = vp->v_rdev;
mode = S_IFCHR;
/*
* Hack: a tty device that is a controlling terminal
* has a reference from the session structure.
* We cannot easily tell that a character device is
* a controlling terminal, unless it is the closing
* process' controlling terminal. In that case,
* if the reference count is 2 (this last descriptor
* plus the session), release the reference from the session.
*/
if (vcount(vp) == 2 && ap->a_p &&
(vp->v_flag & VXLOCK) == 0 &&
vp == ap->a_p->p_session->s_ttyvp) {
vrele(vp);
ap->a_p->p_session->s_ttyvp = NULL;
}
if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0)
return (0);
break;
case VBLK:
devswp = vp->v_rdev->si_devsw;
dev = vp->v_rdev;
mode = S_IFBLK;
/*
* On last close of a block device (that isn't mounted)
* we must invalidate any in core blocks, so that
* we can, for instance, change floppy disks.
*/
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_p);
error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0);
VOP_UNLOCK(vp, 0, ap->a_p);
if (error)
return (error);
break;
default:
panic("devfs_close: not special");
}
/*
* If the vnode is locked, then we are in the midst
* of forcably closing the device, otherwise we would normally
* only close on last reference.
* We do not want to really close the device if it
* is still in use unless we are trying to close it
* forcibly. Since every use (buffer, vnode, swap, cmap)
* holds a reference to the vnode, and because we mark
* any other vnodes that alias this device, when the
* sum of the reference counts on all the aliased
* vnodes descends to one, we are on last close.
* defeat this however if the device wants to be told of every
* close.
*/
if ((vp->v_flag & VXLOCK)
|| (devswp->d_flags & D_TRACKCLOSE)
|| (vcount(vp) <= 1)) {
return ((*devswp->d_close)(dev, ap->a_fflag, mode, ap->a_p));
}
return (0);
}
/*
* Special device advisory byte-level locks.
struct vop_advlock_args {
struct vnode *a_vp;
caddr_t a_id;
int a_op;
struct flock *a_fl;
int a_flags;
}
*/
/* ARGSUSED */
static int
devfs_advlock(struct vop_advlock_args *ap)
{
return (ap->a_flags & F_FLOCK ? EOPNOTSUPP : EINVAL);
}
/*
* Special device bad operation
*/
static int
devfs_badop(void)
{
panic("devfs_badop called");
/* NOTREACHED */
}
static void
devfs_getpages_iodone(struct buf *bp)
{
bp->b_flags |= B_DONE;
wakeup(bp);
}
static int
devfs_getpages(struct vop_getpages_args *ap)
{
vm_offset_t kva;
int error;
int i, pcount, size, s;
daddr_t blkno;
struct buf *bp;
vm_page_t m;
vm_ooffset_t offset;
int toff, nextoff, nread;
struct vnode *vp = ap->a_vp;
int blksiz;
int gotreqpage;
error = 0;
pcount = round_page(ap->a_count) / PAGE_SIZE;
/*
* Calculate the offset of the transfer and do sanity check.
* FreeBSD currently only supports an 8 TB range due to b_blkno
* being in DEV_BSIZE ( usually 512 ) byte chunks on call to
* VOP_STRATEGY. XXX
*/
offset = IDX_TO_OFF(ap->a_m[0]->pindex) + ap->a_offset;
#define DADDR_T_BIT (sizeof(daddr_t)*8)
#define OFFSET_MAX ((1LL << (DADDR_T_BIT + DEV_BSHIFT)) - 1)
if (offset < 0 || offset > OFFSET_MAX) {
/* XXX still no %q in kernel. */
printf("devfs_getpages: preposterous offset 0x%x%08x\n",
(u_int)((u_quad_t)offset >> 32),
(u_int)(offset & 0xffffffff));
return (VM_PAGER_ERROR);
}
blkno = btodb(offset);
/*
* Round up physical size for real devices. We cannot round using
* v_mount's block size data because v_mount has nothing to do with
* the device. i.e. it's usually '/dev'. We need the physical block
* size for the device itself.
*
* We can't use v_specmountpoint because it only exists when the
* block device is mounted. However, we can use v_rdev.
*/
if (vp->v_type == VBLK)
blksiz = vp->v_rdev->si_bsize_phys;
else
blksiz = DEV_BSIZE;
size = (ap->a_count + blksiz - 1) & ~(blksiz - 1);
bp = getpbuf(NULL);
kva = (vm_offset_t)bp->b_data;
/*
* Map the pages to be read into the kva.
*/
pmap_qenter(kva, ap->a_m, pcount);
/* Build a minimal buffer header. */
bp->b_flags = B_READ | B_CALL;
bp->b_iodone = devfs_getpages_iodone;
/* B_PHYS is not set, but it is nice to fill this in. */
bp->b_rcred = bp->b_wcred = curproc->p_ucred;
if (bp->b_rcred != NOCRED)
crhold(bp->b_rcred);
if (bp->b_wcred != NOCRED)
crhold(bp->b_wcred);
bp->b_blkno = blkno;
bp->b_lblkno = blkno;
pbgetvp(vp, bp);
bp->b_bcount = size;
bp->b_bufsize = size;
bp->b_resid = 0;
cnt.v_vnodein++;
cnt.v_vnodepgsin += pcount;
/* Do the input. */
VOP_STRATEGY(bp->b_vp, bp);
s = splbio();
/* We definitely need to be at splbio here. */
while ((bp->b_flags & B_DONE) == 0)
tsleep(bp, PVM, "spread", 0);
splx(s);
if ((bp->b_flags & B_ERROR) != 0) {
if (bp->b_error)
error = bp->b_error;
else
error = EIO;
}
nread = size - bp->b_resid;
if (nread < ap->a_count) {
bzero((caddr_t)kva + nread,
ap->a_count - nread);
}
pmap_qremove(kva, pcount);
gotreqpage = 0;
for (i = 0, toff = 0; i < pcount; i++, toff = nextoff) {
nextoff = toff + PAGE_SIZE;
m = ap->a_m[i];
m->flags &= ~PG_ZERO;
if (nextoff <= nread) {
m->valid = VM_PAGE_BITS_ALL;
vm_page_undirty(m);
} else if (toff < nread) {
/*
* Since this is a VM request, we have to supply the
* unaligned offset to allow vm_page_set_validclean()
* to zero sub-DEV_BSIZE'd portions of the page.
*/
vm_page_set_validclean(m, 0, nread - toff);
} else {
m->valid = 0;
vm_page_undirty(m);
}
if (i != ap->a_reqpage) {
/*
* Just in case someone was asking for this page we
* now tell them that it is ok to use.
*/
if (!error || (m->valid == VM_PAGE_BITS_ALL)) {
if (m->valid) {
if (m->flags & PG_WANTED) {
vm_page_activate(m);
} else {
vm_page_deactivate(m);
}
vm_page_wakeup(m);
} else {
vm_page_free(m);
}
} else {
vm_page_free(m);
}
} else if (m->valid) {
gotreqpage = 1;
/*
* Since this is a VM request, we need to make the
* entire page presentable by zeroing invalid sections.
*/
if (m->valid != VM_PAGE_BITS_ALL)
vm_page_zero_invalid(m, FALSE);
}
}
if (!gotreqpage) {
m = ap->a_m[ap->a_reqpage];
#ifndef MAX_PERF
printf("devfs_getpages: I/O read failure: (error code=%d)\n",
error);
printf(" size: %d, resid:"
" %ld, a_count: %d, valid: 0x%x\n",
size, bp->b_resid, ap->a_count, m->valid);
printf(" nread: %d, reqpage:"
" %d, pindex: %d, pcount: %d\n",
nread, ap->a_reqpage, m->pindex, pcount);
#endif
/*
* Free the buffer header back to the swap buffer pool.
*/
relpbuf(bp, NULL);
return VM_PAGER_ERROR;
}
/*
* Free the buffer header back to the swap buffer pool.
*/
relpbuf(bp, NULL);
return VM_PAGER_OK;
}
/* These are the operations used by directories etc in a devfs */
vop_t **devfs_vnodeop_p;
static struct vnodeopv_entry_desc devfs_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) vop_defaultop },
{ &vop_access_desc, (vop_t *) devfs_access },
{ &vop_bmap_desc, (vop_t *) devfs_badop },
{ &vop_getattr_desc, (vop_t *) devfs_getattr },
{ &vop_inactive_desc, (vop_t *) devfs_inactive },
{ &vop_link_desc, (vop_t *) devfs_link },
{ &vop_lookup_desc, (vop_t *) devfs_lookup },
{ &vop_pathconf_desc, (vop_t *) vop_stdpathconf },
{ &vop_print_desc, (vop_t *) devfs_print },
{ &vop_read_desc, (vop_t *) devfs_xread },
{ &vop_readdir_desc, (vop_t *) devfs_readdir },
{ &vop_readlink_desc, (vop_t *) devfs_readlink },
{ &vop_reclaim_desc, (vop_t *) devfs_reclaim },
{ &vop_remove_desc, (vop_t *) devfs_remove },
{ &vop_rename_desc, (vop_t *) devfs_rename },
{ &vop_setattr_desc, (vop_t *) devfs_setattr },
{ &vop_symlink_desc, (vop_t *) devfs_symlink },
{ &vop_write_desc, (vop_t *) devfs_xwrite },
{ NULL, NULL }
};
static struct vnodeopv_desc devfs_vnodeop_opv_desc =
{ &devfs_vnodeop_p, devfs_vnodeop_entries };
VNODEOP_SET(devfs_vnodeop_opv_desc);
vop_t **devfs_spec_vnodeop_p;
static struct vnodeopv_entry_desc devfs_spec_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) vop_defaultop },
{ &vop_access_desc, (vop_t *) devfs_access },
{ &vop_advlock_desc, (vop_t *) devfs_advlock },
{ &vop_bmap_desc, (vop_t *) devfs_bmap },
{ &vop_close_desc, (vop_t *) devfs_close },
{ &vop_create_desc, (vop_t *) devfs_badop },
{ &vop_freeblks_desc, (vop_t *) devfs_freeblks },
{ &vop_fsync_desc, (vop_t *) devfs_fsync },
{ &vop_getattr_desc, (vop_t *) devfs_getattr },
{ &vop_getpages_desc, (vop_t *) devfs_getpages },
{ &vop_inactive_desc, (vop_t *) devfs_inactive },
{ &vop_ioctl_desc, (vop_t *) devfs_ioctl },
{ &vop_lease_desc, (vop_t *) vop_null },
{ &vop_link_desc, (vop_t *) devfs_badop },
{ &vop_lookup_desc, (vop_t *) devfs_lookup },
{ &vop_mkdir_desc, (vop_t *) devfs_badop },
{ &vop_mknod_desc, (vop_t *) devfs_badop },
{ &vop_open_desc, (vop_t *) devfs_open },
{ &vop_pathconf_desc, (vop_t *) vop_stdpathconf },
{ &vop_poll_desc, (vop_t *) devfs_poll },
{ &vop_print_desc, (vop_t *) devfs_print },
{ &vop_read_desc, (vop_t *) devfs_read },
{ &vop_readdir_desc, (vop_t *) devfs_badop },
{ &vop_readlink_desc, (vop_t *) devfs_badop },
{ &vop_reallocblks_desc, (vop_t *) devfs_badop },
{ &vop_reclaim_desc, (vop_t *) devfs_reclaim },
{ &vop_remove_desc, (vop_t *) devfs_badop },
{ &vop_rename_desc, (vop_t *) devfs_badop },
{ &vop_rmdir_desc, (vop_t *) devfs_badop },
{ &vop_setattr_desc, (vop_t *) devfs_setattr },
{ &vop_strategy_desc, (vop_t *) devfs_strategy },
{ &vop_symlink_desc, (vop_t *) devfs_symlink },
{ &vop_write_desc, (vop_t *) devfs_write },
{ NULL, NULL }
};
static struct vnodeopv_desc devfs_spec_vnodeop_opv_desc =
{ &devfs_spec_vnodeop_p, devfs_spec_vnodeop_entries };
VNODEOP_SET(devfs_spec_vnodeop_opv_desc);
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