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freebsd-dev/sys/fs/tmpfs/tmpfs_subr.c
Gleb Smirnoff b0cd20172d A change to KPI of vm_pager_get_pages() and underlying VOP_GETPAGES(). 
o With new KPI consumers can request contiguous ranges of pages, and
  unlike before, all pages will be kept busied on return, like it was
  done before with the 'reqpage' only. Now the reqpage goes away. With
  new interface it is easier to implement code protected from race
  conditions.

  Such arrayed requests for now should be preceeded by a call to
  vm_pager_haspage() to make sure that request is possible. This
  could be improved later, making vm_pager_haspage() obsolete.

  Strenghtening the promises on the business of the array of pages
  allows us to remove such hacks as swp_pager_free_nrpage() and
  vm_pager_free_nonreq().

o New KPI accepts two integer pointers that may optionally point at
  values for read ahead and read behind, that a pager may do, if it
  can. These pages are completely owned by pager, and not controlled
  by the caller.

  This shifts the UFS-specific readahead logic from vm_fault.c, which
  should be file system agnostic, into vnode_pager.c. It also removes
  one VOP_BMAP() request per hard fault.

Discussed with:	kib, alc, jeff, scottl
Sponsored by:	Nginx, Inc.
Sponsored by:	Netflix
2015-12-16 21:30:45 +00:00

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/* $NetBSD: tmpfs_subr.c,v 1.35 2007/07/09 21:10:50 ad Exp $ */
/*-
* Copyright (c) 2005 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Julio M. Merino Vidal, developed as part of Google's Summer of Code
* 2005 program.
*
* 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Efficient memory file system supporting functions.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/fnv_hash.h>
#include <sys/lock.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/random.h>
#include <sys/rwlock.h>
#include <sys/stat.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/vnode.h>
#include <sys/vmmeter.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pageout.h>
#include <vm/vm_pager.h>
#include <vm/vm_extern.h>
#include <fs/tmpfs/tmpfs.h>
#include <fs/tmpfs/tmpfs_fifoops.h>
#include <fs/tmpfs/tmpfs_vnops.h>
struct tmpfs_dir_cursor {
struct tmpfs_dirent *tdc_current;
struct tmpfs_dirent *tdc_tree;
};
SYSCTL_NODE(_vfs, OID_AUTO, tmpfs, CTLFLAG_RW, 0, "tmpfs file system");
static long tmpfs_pages_reserved = TMPFS_PAGES_MINRESERVED;
static int
sysctl_mem_reserved(SYSCTL_HANDLER_ARGS)
{
int error;
long pages, bytes;
pages = *(long *)arg1;
bytes = pages * PAGE_SIZE;
error = sysctl_handle_long(oidp, &bytes, 0, req);
if (error || !req->newptr)
return (error);
pages = bytes / PAGE_SIZE;
if (pages < TMPFS_PAGES_MINRESERVED)
return (EINVAL);
*(long *)arg1 = pages;
return (0);
}
SYSCTL_PROC(_vfs_tmpfs, OID_AUTO, memory_reserved, CTLTYPE_LONG|CTLFLAG_RW,
&tmpfs_pages_reserved, 0, sysctl_mem_reserved, "L",
"Amount of available memory and swap below which tmpfs growth stops");
static __inline int tmpfs_dirtree_cmp(struct tmpfs_dirent *a,
struct tmpfs_dirent *b);
RB_PROTOTYPE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp);
size_t
tmpfs_mem_avail(void)
{
vm_ooffset_t avail;
avail = swap_pager_avail + vm_cnt.v_free_count + vm_cnt.v_cache_count -
tmpfs_pages_reserved;
if (__predict_false(avail < 0))
avail = 0;
return (avail);
}
size_t
tmpfs_pages_used(struct tmpfs_mount *tmp)
{
const size_t node_size = sizeof(struct tmpfs_node) +
sizeof(struct tmpfs_dirent);
size_t meta_pages;
meta_pages = howmany((uintmax_t)tmp->tm_nodes_inuse * node_size,
PAGE_SIZE);
return (meta_pages + tmp->tm_pages_used);
}
static size_t
tmpfs_pages_check_avail(struct tmpfs_mount *tmp, size_t req_pages)
{
if (tmpfs_mem_avail() < req_pages)
return (0);
if (tmp->tm_pages_max != SIZE_MAX &&
tmp->tm_pages_max < req_pages + tmpfs_pages_used(tmp))
return (0);
return (1);
}
/*
* Allocates a new node of type 'type' inside the 'tmp' mount point, with
* its owner set to 'uid', its group to 'gid' and its mode set to 'mode',
* using the credentials of the process 'p'.
*
* If the node type is set to 'VDIR', then the parent parameter must point
* to the parent directory of the node being created. It may only be NULL
* while allocating the root node.
*
* If the node type is set to 'VBLK' or 'VCHR', then the rdev parameter
* specifies the device the node represents.
*
* If the node type is set to 'VLNK', then the parameter target specifies
* the file name of the target file for the symbolic link that is being
* created.
*
* Note that new nodes are retrieved from the available list if it has
* items or, if it is empty, from the node pool as long as there is enough
* space to create them.
*
* Returns zero on success or an appropriate error code on failure.
*/
int
tmpfs_alloc_node(struct mount *mp, struct tmpfs_mount *tmp, enum vtype type,
uid_t uid, gid_t gid, mode_t mode, struct tmpfs_node *parent,
char *target, dev_t rdev, struct tmpfs_node **node)
{
struct tmpfs_node *nnode;
vm_object_t obj;
/* If the root directory of the 'tmp' file system is not yet
* allocated, this must be the request to do it. */
MPASS(IMPLIES(tmp->tm_root == NULL, parent == NULL && type == VDIR));
KASSERT(tmp->tm_root == NULL || mp->mnt_writeopcount > 0,
("creating node not under vn_start_write"));
MPASS(IFF(type == VLNK, target != NULL));
MPASS(IFF(type == VBLK || type == VCHR, rdev != VNOVAL));
if (tmp->tm_nodes_inuse >= tmp->tm_nodes_max)
return (ENOSPC);
if (tmpfs_pages_check_avail(tmp, 1) == 0)
return (ENOSPC);
if ((mp->mnt_kern_flag & MNTK_UNMOUNT) != 0) {
/*
* When a new tmpfs node is created for fully
* constructed mount point, there must be a parent
* node, which vnode is locked exclusively. As
* consequence, if the unmount is executing in
* parallel, vflush() cannot reclaim the parent vnode.
* Due to this, the check for MNTK_UNMOUNT flag is not
* racy: if we did not see MNTK_UNMOUNT flag, then tmp
* cannot be destroyed until node construction is
* finished and the parent vnode unlocked.
*
* Tmpfs does not need to instantiate new nodes during
* unmount.
*/
return (EBUSY);
}
nnode = (struct tmpfs_node *)uma_zalloc_arg(
tmp->tm_node_pool, tmp, M_WAITOK);
/* Generic initialization. */
nnode->tn_type = type;
vfs_timestamp(&nnode->tn_atime);
nnode->tn_birthtime = nnode->tn_ctime = nnode->tn_mtime =
nnode->tn_atime;
nnode->tn_uid = uid;
nnode->tn_gid = gid;
nnode->tn_mode = mode;
nnode->tn_id = alloc_unr(tmp->tm_ino_unr);
/* Type-specific initialization. */
switch (nnode->tn_type) {
case VBLK:
case VCHR:
nnode->tn_rdev = rdev;
break;
case VDIR:
RB_INIT(&nnode->tn_dir.tn_dirhead);
LIST_INIT(&nnode->tn_dir.tn_dupindex);
MPASS(parent != nnode);
MPASS(IMPLIES(parent == NULL, tmp->tm_root == NULL));
nnode->tn_dir.tn_parent = (parent == NULL) ? nnode : parent;
nnode->tn_dir.tn_readdir_lastn = 0;
nnode->tn_dir.tn_readdir_lastp = NULL;
nnode->tn_links++;
TMPFS_NODE_LOCK(nnode->tn_dir.tn_parent);
nnode->tn_dir.tn_parent->tn_links++;
TMPFS_NODE_UNLOCK(nnode->tn_dir.tn_parent);
break;
case VFIFO:
/* FALLTHROUGH */
case VSOCK:
break;
case VLNK:
MPASS(strlen(target) < MAXPATHLEN);
nnode->tn_size = strlen(target);
nnode->tn_link = malloc(nnode->tn_size, M_TMPFSNAME,
M_WAITOK);
memcpy(nnode->tn_link, target, nnode->tn_size);
break;
case VREG:
obj = nnode->tn_reg.tn_aobj =
vm_pager_allocate(OBJT_SWAP, NULL, 0, VM_PROT_DEFAULT, 0,
NULL /* XXXKIB - tmpfs needs swap reservation */);
VM_OBJECT_WLOCK(obj);
/* OBJ_TMPFS is set together with the setting of vp->v_object */
vm_object_set_flag(obj, OBJ_NOSPLIT | OBJ_TMPFS_NODE);
vm_object_clear_flag(obj, OBJ_ONEMAPPING);
VM_OBJECT_WUNLOCK(obj);
break;
default:
panic("tmpfs_alloc_node: type %p %d", nnode, (int)nnode->tn_type);
}
TMPFS_LOCK(tmp);
LIST_INSERT_HEAD(&tmp->tm_nodes_used, nnode, tn_entries);
tmp->tm_nodes_inuse++;
TMPFS_UNLOCK(tmp);
*node = nnode;
return 0;
}
/*
* Destroys the node pointed to by node from the file system 'tmp'.
* If the node does not belong to the given mount point, the results are
* unpredicted.
*
* If the node references a directory; no entries are allowed because
* their removal could need a recursive algorithm, something forbidden in
* kernel space. Furthermore, there is not need to provide such
* functionality (recursive removal) because the only primitives offered
* to the user are the removal of empty directories and the deletion of
* individual files.
*
* Note that nodes are not really deleted; in fact, when a node has been
* allocated, it cannot be deleted during the whole life of the file
* system. Instead, they are moved to the available list and remain there
* until reused.
*/
void
tmpfs_free_node(struct tmpfs_mount *tmp, struct tmpfs_node *node)
{
vm_object_t uobj;
#ifdef INVARIANTS
TMPFS_NODE_LOCK(node);
MPASS(node->tn_vnode == NULL);
MPASS((node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0);
TMPFS_NODE_UNLOCK(node);
#endif
TMPFS_LOCK(tmp);
LIST_REMOVE(node, tn_entries);
tmp->tm_nodes_inuse--;
TMPFS_UNLOCK(tmp);
switch (node->tn_type) {
case VNON:
/* Do not do anything. VNON is provided to let the
* allocation routine clean itself easily by avoiding
* duplicating code in it. */
/* FALLTHROUGH */
case VBLK:
/* FALLTHROUGH */
case VCHR:
/* FALLTHROUGH */
case VDIR:
/* FALLTHROUGH */
case VFIFO:
/* FALLTHROUGH */
case VSOCK:
break;
case VLNK:
free(node->tn_link, M_TMPFSNAME);
break;
case VREG:
uobj = node->tn_reg.tn_aobj;
if (uobj != NULL) {
TMPFS_LOCK(tmp);
tmp->tm_pages_used -= uobj->size;
TMPFS_UNLOCK(tmp);
KASSERT((uobj->flags & OBJ_TMPFS) == 0,
("leaked OBJ_TMPFS node %p vm_obj %p", node, uobj));
vm_object_deallocate(uobj);
}
break;
default:
panic("tmpfs_free_node: type %p %d", node, (int)node->tn_type);
}
free_unr(tmp->tm_ino_unr, node->tn_id);
uma_zfree(tmp->tm_node_pool, node);
}
static __inline uint32_t
tmpfs_dirent_hash(const char *name, u_int len)
{
uint32_t hash;
hash = fnv_32_buf(name, len, FNV1_32_INIT + len) & TMPFS_DIRCOOKIE_MASK;
#ifdef TMPFS_DEBUG_DIRCOOKIE_DUP
hash &= 0xf;
#endif
if (hash < TMPFS_DIRCOOKIE_MIN)
hash += TMPFS_DIRCOOKIE_MIN;
return (hash);
}
static __inline off_t
tmpfs_dirent_cookie(struct tmpfs_dirent *de)
{
if (de == NULL)
return (TMPFS_DIRCOOKIE_EOF);
MPASS(de->td_cookie >= TMPFS_DIRCOOKIE_MIN);
return (de->td_cookie);
}
static __inline boolean_t
tmpfs_dirent_dup(struct tmpfs_dirent *de)
{
return ((de->td_cookie & TMPFS_DIRCOOKIE_DUP) != 0);
}
static __inline boolean_t
tmpfs_dirent_duphead(struct tmpfs_dirent *de)
{
return ((de->td_cookie & TMPFS_DIRCOOKIE_DUPHEAD) != 0);
}
void
tmpfs_dirent_init(struct tmpfs_dirent *de, const char *name, u_int namelen)
{
de->td_hash = de->td_cookie = tmpfs_dirent_hash(name, namelen);
memcpy(de->ud.td_name, name, namelen);
de->td_namelen = namelen;
}
/*
* Allocates a new directory entry for the node node with a name of name.
* The new directory entry is returned in *de.
*
* The link count of node is increased by one to reflect the new object
* referencing it.
*
* Returns zero on success or an appropriate error code on failure.
*/
int
tmpfs_alloc_dirent(struct tmpfs_mount *tmp, struct tmpfs_node *node,
const char *name, u_int len, struct tmpfs_dirent **de)
{
struct tmpfs_dirent *nde;
nde = uma_zalloc(tmp->tm_dirent_pool, M_WAITOK);
nde->td_node = node;
if (name != NULL) {
nde->ud.td_name = malloc(len, M_TMPFSNAME, M_WAITOK);
tmpfs_dirent_init(nde, name, len);
} else
nde->td_namelen = 0;
if (node != NULL)
node->tn_links++;
*de = nde;
return 0;
}
/*
* Frees a directory entry. It is the caller's responsibility to destroy
* the node referenced by it if needed.
*
* The link count of node is decreased by one to reflect the removal of an
* object that referenced it. This only happens if 'node_exists' is true;
* otherwise the function will not access the node referred to by the
* directory entry, as it may already have been released from the outside.
*/
void
tmpfs_free_dirent(struct tmpfs_mount *tmp, struct tmpfs_dirent *de)
{
struct tmpfs_node *node;
node = de->td_node;
if (node != NULL) {
MPASS(node->tn_links > 0);
node->tn_links--;
}
if (!tmpfs_dirent_duphead(de) && de->ud.td_name != NULL)
free(de->ud.td_name, M_TMPFSNAME);
uma_zfree(tmp->tm_dirent_pool, de);
}
void
tmpfs_destroy_vobject(struct vnode *vp, vm_object_t obj)
{
ASSERT_VOP_ELOCKED(vp, "tmpfs_destroy_vobject");
if (vp->v_type != VREG || obj == NULL)
return;
VM_OBJECT_WLOCK(obj);
VI_LOCK(vp);
vm_object_clear_flag(obj, OBJ_TMPFS);
obj->un_pager.swp.swp_tmpfs = NULL;
VI_UNLOCK(vp);
VM_OBJECT_WUNLOCK(obj);
}
/*
* Need to clear v_object for insmntque failure.
*/
static void
tmpfs_insmntque_dtr(struct vnode *vp, void *dtr_arg)
{
tmpfs_destroy_vobject(vp, vp->v_object);
vp->v_object = NULL;
vp->v_data = NULL;
vp->v_op = &dead_vnodeops;
vgone(vp);
vput(vp);
}
/*
* Allocates a new vnode for the node node or returns a new reference to
* an existing one if the node had already a vnode referencing it. The
* resulting locked vnode is returned in *vpp.
*
* Returns zero on success or an appropriate error code on failure.
*/
int
tmpfs_alloc_vp(struct mount *mp, struct tmpfs_node *node, int lkflag,
struct vnode **vpp)
{
struct vnode *vp;
vm_object_t object;
int error;
error = 0;
loop:
TMPFS_NODE_LOCK(node);
loop1:
if ((vp = node->tn_vnode) != NULL) {
MPASS((node->tn_vpstate & TMPFS_VNODE_DOOMED) == 0);
VI_LOCK(vp);
if ((node->tn_type == VDIR && node->tn_dir.tn_parent == NULL) ||
((vp->v_iflag & VI_DOOMED) != 0 &&
(lkflag & LK_NOWAIT) != 0)) {
VI_UNLOCK(vp);
TMPFS_NODE_UNLOCK(node);
error = ENOENT;
vp = NULL;
goto out;
}
if ((vp->v_iflag & VI_DOOMED) != 0) {
VI_UNLOCK(vp);
node->tn_vpstate |= TMPFS_VNODE_WRECLAIM;
while ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0) {
msleep(&node->tn_vnode, TMPFS_NODE_MTX(node),
0, "tmpfsE", 0);
}
goto loop1;
}
TMPFS_NODE_UNLOCK(node);
error = vget(vp, lkflag | LK_INTERLOCK, curthread);
if (error == ENOENT)
goto loop;
if (error != 0) {
vp = NULL;
goto out;
}
/*
* Make sure the vnode is still there after
* getting the interlock to avoid racing a free.
*/
if (node->tn_vnode == NULL || node->tn_vnode != vp) {
vput(vp);
goto loop;
}
goto out;
}
if ((node->tn_vpstate & TMPFS_VNODE_DOOMED) ||
(node->tn_type == VDIR && node->tn_dir.tn_parent == NULL)) {
TMPFS_NODE_UNLOCK(node);
error = ENOENT;
vp = NULL;
goto out;
}
/*
* otherwise lock the vp list while we call getnewvnode
* since that can block.
*/
if (node->tn_vpstate & TMPFS_VNODE_ALLOCATING) {
node->tn_vpstate |= TMPFS_VNODE_WANT;
error = msleep((caddr_t) &node->tn_vpstate,
TMPFS_NODE_MTX(node), PDROP | PCATCH,
"tmpfs_alloc_vp", 0);
if (error)
return error;
goto loop;
} else
node->tn_vpstate |= TMPFS_VNODE_ALLOCATING;
TMPFS_NODE_UNLOCK(node);
/* Get a new vnode and associate it with our node. */
error = getnewvnode("tmpfs", mp, &tmpfs_vnodeop_entries, &vp);
if (error != 0)
goto unlock;
MPASS(vp != NULL);
/* lkflag is ignored, the lock is exclusive */
(void) vn_lock(vp, lkflag | LK_RETRY);
vp->v_data = node;
vp->v_type = node->tn_type;
/* Type-specific initialization. */
switch (node->tn_type) {
case VBLK:
/* FALLTHROUGH */
case VCHR:
/* FALLTHROUGH */
case VLNK:
/* FALLTHROUGH */
case VSOCK:
break;
case VFIFO:
vp->v_op = &tmpfs_fifoop_entries;
break;
case VREG:
object = node->tn_reg.tn_aobj;
VM_OBJECT_WLOCK(object);
VI_LOCK(vp);
KASSERT(vp->v_object == NULL, ("Not NULL v_object in tmpfs"));
vp->v_object = object;
object->un_pager.swp.swp_tmpfs = vp;
vm_object_set_flag(object, OBJ_TMPFS);
VI_UNLOCK(vp);
VM_OBJECT_WUNLOCK(object);
break;
case VDIR:
MPASS(node->tn_dir.tn_parent != NULL);
if (node->tn_dir.tn_parent == node)
vp->v_vflag |= VV_ROOT;
break;
default:
panic("tmpfs_alloc_vp: type %p %d", node, (int)node->tn_type);
}
if (vp->v_type != VFIFO)
VN_LOCK_ASHARE(vp);
error = insmntque1(vp, mp, tmpfs_insmntque_dtr, NULL);
if (error)
vp = NULL;
unlock:
TMPFS_NODE_LOCK(node);
MPASS(node->tn_vpstate & TMPFS_VNODE_ALLOCATING);
node->tn_vpstate &= ~TMPFS_VNODE_ALLOCATING;
node->tn_vnode = vp;
if (node->tn_vpstate & TMPFS_VNODE_WANT) {
node->tn_vpstate &= ~TMPFS_VNODE_WANT;
TMPFS_NODE_UNLOCK(node);
wakeup((caddr_t) &node->tn_vpstate);
} else
TMPFS_NODE_UNLOCK(node);
out:
*vpp = vp;
#ifdef INVARIANTS
if (error == 0) {
MPASS(*vpp != NULL && VOP_ISLOCKED(*vpp));
TMPFS_NODE_LOCK(node);
MPASS(*vpp == node->tn_vnode);
TMPFS_NODE_UNLOCK(node);
}
#endif
return error;
}
/*
* Destroys the association between the vnode vp and the node it
* references.
*/
void
tmpfs_free_vp(struct vnode *vp)
{
struct tmpfs_node *node;
node = VP_TO_TMPFS_NODE(vp);
TMPFS_NODE_ASSERT_LOCKED(node);
node->tn_vnode = NULL;
if ((node->tn_vpstate & TMPFS_VNODE_WRECLAIM) != 0)
wakeup(&node->tn_vnode);
node->tn_vpstate &= ~TMPFS_VNODE_WRECLAIM;
vp->v_data = NULL;
}
/*
* Allocates a new file of type 'type' and adds it to the parent directory
* 'dvp'; this addition is done using the component name given in 'cnp'.
* The ownership of the new file is automatically assigned based on the
* credentials of the caller (through 'cnp'), the group is set based on
* the parent directory and the mode is determined from the 'vap' argument.
* If successful, *vpp holds a vnode to the newly created file and zero
* is returned. Otherwise *vpp is NULL and the function returns an
* appropriate error code.
*/
int
tmpfs_alloc_file(struct vnode *dvp, struct vnode **vpp, struct vattr *vap,
struct componentname *cnp, char *target)
{
int error;
struct tmpfs_dirent *de;
struct tmpfs_mount *tmp;
struct tmpfs_node *dnode;
struct tmpfs_node *node;
struct tmpfs_node *parent;
MPASS(VOP_ISLOCKED(dvp));
MPASS(cnp->cn_flags & HASBUF);
tmp = VFS_TO_TMPFS(dvp->v_mount);
dnode = VP_TO_TMPFS_DIR(dvp);
*vpp = NULL;
/* If the entry we are creating is a directory, we cannot overflow
* the number of links of its parent, because it will get a new
* link. */
if (vap->va_type == VDIR) {
/* Ensure that we do not overflow the maximum number of links
* imposed by the system. */
MPASS(dnode->tn_links <= LINK_MAX);
if (dnode->tn_links == LINK_MAX) {
return (EMLINK);
}
parent = dnode;
MPASS(parent != NULL);
} else
parent = NULL;
/* Allocate a node that represents the new file. */
error = tmpfs_alloc_node(dvp->v_mount, tmp, vap->va_type,
cnp->cn_cred->cr_uid,
dnode->tn_gid, vap->va_mode, parent, target, vap->va_rdev, &node);
if (error != 0)
return (error);
/* Allocate a directory entry that points to the new file. */
error = tmpfs_alloc_dirent(tmp, node, cnp->cn_nameptr, cnp->cn_namelen,
&de);
if (error != 0) {
tmpfs_free_node(tmp, node);
return (error);
}
/* Allocate a vnode for the new file. */
error = tmpfs_alloc_vp(dvp->v_mount, node, LK_EXCLUSIVE, vpp);
if (error != 0) {
tmpfs_free_dirent(tmp, de);
tmpfs_free_node(tmp, node);
return (error);
}
/* Now that all required items are allocated, we can proceed to
* insert the new node into the directory, an operation that
* cannot fail. */
if (cnp->cn_flags & ISWHITEOUT)
tmpfs_dir_whiteout_remove(dvp, cnp);
tmpfs_dir_attach(dvp, de);
return (0);
}
static struct tmpfs_dirent *
tmpfs_dir_first(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc)
{
struct tmpfs_dirent *de;
de = RB_MIN(tmpfs_dir, &dnode->tn_dir.tn_dirhead);
dc->tdc_tree = de;
if (de != NULL && tmpfs_dirent_duphead(de))
de = LIST_FIRST(&de->ud.td_duphead);
dc->tdc_current = de;
return (dc->tdc_current);
}
static struct tmpfs_dirent *
tmpfs_dir_next(struct tmpfs_node *dnode, struct tmpfs_dir_cursor *dc)
{
struct tmpfs_dirent *de;
MPASS(dc->tdc_tree != NULL);
if (tmpfs_dirent_dup(dc->tdc_current)) {
dc->tdc_current = LIST_NEXT(dc->tdc_current, uh.td_dup.entries);
if (dc->tdc_current != NULL)
return (dc->tdc_current);
}
dc->tdc_tree = dc->tdc_current = RB_NEXT(tmpfs_dir,
&dnode->tn_dir.tn_dirhead, dc->tdc_tree);
if ((de = dc->tdc_current) != NULL && tmpfs_dirent_duphead(de)) {
dc->tdc_current = LIST_FIRST(&de->ud.td_duphead);
MPASS(dc->tdc_current != NULL);
}
return (dc->tdc_current);
}
/* Lookup directory entry in RB-Tree. Function may return duphead entry. */
static struct tmpfs_dirent *
tmpfs_dir_xlookup_hash(struct tmpfs_node *dnode, uint32_t hash)
{
struct tmpfs_dirent *de, dekey;
dekey.td_hash = hash;
de = RB_FIND(tmpfs_dir, &dnode->tn_dir.tn_dirhead, &dekey);
return (de);
}
/* Lookup directory entry by cookie, initialize directory cursor accordingly. */
static struct tmpfs_dirent *
tmpfs_dir_lookup_cookie(struct tmpfs_node *node, off_t cookie,
struct tmpfs_dir_cursor *dc)
{
struct tmpfs_dir *dirhead = &node->tn_dir.tn_dirhead;
struct tmpfs_dirent *de, dekey;
MPASS(cookie >= TMPFS_DIRCOOKIE_MIN);
if (cookie == node->tn_dir.tn_readdir_lastn &&
(de = node->tn_dir.tn_readdir_lastp) != NULL) {
/* Protect against possible race, tn_readdir_last[pn]
* may be updated with only shared vnode lock held. */
if (cookie == tmpfs_dirent_cookie(de))
goto out;
}
if ((cookie & TMPFS_DIRCOOKIE_DUP) != 0) {
LIST_FOREACH(de, &node->tn_dir.tn_dupindex,
uh.td_dup.index_entries) {
MPASS(tmpfs_dirent_dup(de));
if (de->td_cookie == cookie)
goto out;
/* dupindex list is sorted. */
if (de->td_cookie < cookie) {
de = NULL;
goto out;
}
}
MPASS(de == NULL);
goto out;
}
MPASS((cookie & TMPFS_DIRCOOKIE_MASK) == cookie);
dekey.td_hash = cookie;
/* Recover if direntry for cookie was removed */
de = RB_NFIND(tmpfs_dir, dirhead, &dekey);
dc->tdc_tree = de;
dc->tdc_current = de;
if (de != NULL && tmpfs_dirent_duphead(de)) {
dc->tdc_current = LIST_FIRST(&de->ud.td_duphead);
MPASS(dc->tdc_current != NULL);
}
return (dc->tdc_current);
out:
dc->tdc_tree = de;
dc->tdc_current = de;
if (de != NULL && tmpfs_dirent_dup(de))
dc->tdc_tree = tmpfs_dir_xlookup_hash(node,
de->td_hash);
return (dc->tdc_current);
}
/*
* Looks for a directory entry in the directory represented by node.
* 'cnp' describes the name of the entry to look for. Note that the .
* and .. components are not allowed as they do not physically exist
* within directories.
*
* Returns a pointer to the entry when found, otherwise NULL.
*/
struct tmpfs_dirent *
tmpfs_dir_lookup(struct tmpfs_node *node, struct tmpfs_node *f,
struct componentname *cnp)
{
struct tmpfs_dir_duphead *duphead;
struct tmpfs_dirent *de;
uint32_t hash;
MPASS(IMPLIES(cnp->cn_namelen == 1, cnp->cn_nameptr[0] != '.'));
MPASS(IMPLIES(cnp->cn_namelen == 2, !(cnp->cn_nameptr[0] == '.' &&
cnp->cn_nameptr[1] == '.')));
TMPFS_VALIDATE_DIR(node);
hash = tmpfs_dirent_hash(cnp->cn_nameptr, cnp->cn_namelen);
de = tmpfs_dir_xlookup_hash(node, hash);
if (de != NULL && tmpfs_dirent_duphead(de)) {
duphead = &de->ud.td_duphead;
LIST_FOREACH(de, duphead, uh.td_dup.entries) {
if (TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr,
cnp->cn_namelen))
break;
}
} else if (de != NULL) {
if (!TMPFS_DIRENT_MATCHES(de, cnp->cn_nameptr,
cnp->cn_namelen))
de = NULL;
}
if (de != NULL && f != NULL && de->td_node != f)
de = NULL;
return (de);
}
/*
* Attach duplicate-cookie directory entry nde to dnode and insert to dupindex
* list, allocate new cookie value.
*/
static void
tmpfs_dir_attach_dup(struct tmpfs_node *dnode,
struct tmpfs_dir_duphead *duphead, struct tmpfs_dirent *nde)
{
struct tmpfs_dir_duphead *dupindex;
struct tmpfs_dirent *de, *pde;
dupindex = &dnode->tn_dir.tn_dupindex;
de = LIST_FIRST(dupindex);
if (de == NULL || de->td_cookie < TMPFS_DIRCOOKIE_DUP_MAX) {
if (de == NULL)
nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN;
else
nde->td_cookie = de->td_cookie + 1;
MPASS(tmpfs_dirent_dup(nde));
LIST_INSERT_HEAD(dupindex, nde, uh.td_dup.index_entries);
LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
return;
}
/*
* Cookie numbers are near exhaustion. Scan dupindex list for unused
* numbers. dupindex list is sorted in descending order. Keep it so
* after inserting nde.
*/
while (1) {
pde = de;
de = LIST_NEXT(de, uh.td_dup.index_entries);
if (de == NULL && pde->td_cookie != TMPFS_DIRCOOKIE_DUP_MIN) {
/*
* Last element of the index doesn't have minimal cookie
* value, use it.
*/
nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MIN;
LIST_INSERT_AFTER(pde, nde, uh.td_dup.index_entries);
LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
return;
} else if (de == NULL) {
/*
* We are so lucky have 2^30 hash duplicates in single
* directory :) Return largest possible cookie value.
* It should be fine except possible issues with
* VOP_READDIR restart.
*/
nde->td_cookie = TMPFS_DIRCOOKIE_DUP_MAX;
LIST_INSERT_HEAD(dupindex, nde,
uh.td_dup.index_entries);
LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
return;
}
if (de->td_cookie + 1 == pde->td_cookie ||
de->td_cookie >= TMPFS_DIRCOOKIE_DUP_MAX)
continue; /* No hole or invalid cookie. */
nde->td_cookie = de->td_cookie + 1;
MPASS(tmpfs_dirent_dup(nde));
MPASS(pde->td_cookie > nde->td_cookie);
MPASS(nde->td_cookie > de->td_cookie);
LIST_INSERT_BEFORE(de, nde, uh.td_dup.index_entries);
LIST_INSERT_HEAD(duphead, nde, uh.td_dup.entries);
return;
};
}
/*
* Attaches the directory entry de to the directory represented by vp.
* Note that this does not change the link count of the node pointed by
* the directory entry, as this is done by tmpfs_alloc_dirent.
*/
void
tmpfs_dir_attach(struct vnode *vp, struct tmpfs_dirent *de)
{
struct tmpfs_node *dnode;
struct tmpfs_dirent *xde, *nde;
ASSERT_VOP_ELOCKED(vp, __func__);
MPASS(de->td_namelen > 0);
MPASS(de->td_hash >= TMPFS_DIRCOOKIE_MIN);
MPASS(de->td_cookie == de->td_hash);
dnode = VP_TO_TMPFS_DIR(vp);
dnode->tn_dir.tn_readdir_lastn = 0;
dnode->tn_dir.tn_readdir_lastp = NULL;
MPASS(!tmpfs_dirent_dup(de));
xde = RB_INSERT(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de);
if (xde != NULL && tmpfs_dirent_duphead(xde))
tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de);
else if (xde != NULL) {
/*
* Allocate new duphead. Swap xde with duphead to avoid
* adding/removing elements with the same hash.
*/
MPASS(!tmpfs_dirent_dup(xde));
tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), NULL, NULL, 0,
&nde);
/* *nde = *xde; XXX gcc 4.2.1 may generate invalid code. */
memcpy(nde, xde, sizeof(*xde));
xde->td_cookie |= TMPFS_DIRCOOKIE_DUPHEAD;
LIST_INIT(&xde->ud.td_duphead);
xde->td_namelen = 0;
xde->td_node = NULL;
tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, nde);
tmpfs_dir_attach_dup(dnode, &xde->ud.td_duphead, de);
}
dnode->tn_size += sizeof(struct tmpfs_dirent);
dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \
TMPFS_NODE_MODIFIED;
tmpfs_update(vp);
}
/*
* Detaches the directory entry de from the directory represented by vp.
* Note that this does not change the link count of the node pointed by
* the directory entry, as this is done by tmpfs_free_dirent.
*/
void
tmpfs_dir_detach(struct vnode *vp, struct tmpfs_dirent *de)
{
struct tmpfs_mount *tmp;
struct tmpfs_dir *head;
struct tmpfs_node *dnode;
struct tmpfs_dirent *xde;
ASSERT_VOP_ELOCKED(vp, __func__);
dnode = VP_TO_TMPFS_DIR(vp);
head = &dnode->tn_dir.tn_dirhead;
dnode->tn_dir.tn_readdir_lastn = 0;
dnode->tn_dir.tn_readdir_lastp = NULL;
if (tmpfs_dirent_dup(de)) {
/* Remove duphead if de was last entry. */
if (LIST_NEXT(de, uh.td_dup.entries) == NULL) {
xde = tmpfs_dir_xlookup_hash(dnode, de->td_hash);
MPASS(tmpfs_dirent_duphead(xde));
} else
xde = NULL;
LIST_REMOVE(de, uh.td_dup.entries);
LIST_REMOVE(de, uh.td_dup.index_entries);
if (xde != NULL) {
if (LIST_EMPTY(&xde->ud.td_duphead)) {
RB_REMOVE(tmpfs_dir, head, xde);
tmp = VFS_TO_TMPFS(vp->v_mount);
MPASS(xde->td_node == NULL);
tmpfs_free_dirent(tmp, xde);
}
}
de->td_cookie = de->td_hash;
} else
RB_REMOVE(tmpfs_dir, head, de);
dnode->tn_size -= sizeof(struct tmpfs_dirent);
dnode->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \
TMPFS_NODE_MODIFIED;
tmpfs_update(vp);
}
void
tmpfs_dir_destroy(struct tmpfs_mount *tmp, struct tmpfs_node *dnode)
{
struct tmpfs_dirent *de, *dde, *nde;
RB_FOREACH_SAFE(de, tmpfs_dir, &dnode->tn_dir.tn_dirhead, nde) {
RB_REMOVE(tmpfs_dir, &dnode->tn_dir.tn_dirhead, de);
/* Node may already be destroyed. */
de->td_node = NULL;
if (tmpfs_dirent_duphead(de)) {
while ((dde = LIST_FIRST(&de->ud.td_duphead)) != NULL) {
LIST_REMOVE(dde, uh.td_dup.entries);
dde->td_node = NULL;
tmpfs_free_dirent(tmp, dde);
}
}
tmpfs_free_dirent(tmp, de);
}
}
/*
* Helper function for tmpfs_readdir. Creates a '.' entry for the given
* directory and returns it in the uio space. The function returns 0
* on success, -1 if there was not enough space in the uio structure to
* hold the directory entry or an appropriate error code if another
* error happens.
*/
static int
tmpfs_dir_getdotdent(struct tmpfs_node *node, struct uio *uio)
{
int error;
struct dirent dent;
TMPFS_VALIDATE_DIR(node);
MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOT);
dent.d_fileno = node->tn_id;
dent.d_type = DT_DIR;
dent.d_namlen = 1;
dent.d_name[0] = '.';
dent.d_name[1] = '\0';
dent.d_reclen = GENERIC_DIRSIZ(&dent);
if (dent.d_reclen > uio->uio_resid)
error = EJUSTRETURN;
else
error = uiomove(&dent, dent.d_reclen, uio);
node->tn_status |= TMPFS_NODE_ACCESSED;
return error;
}
/*
* Helper function for tmpfs_readdir. Creates a '..' entry for the given
* directory and returns it in the uio space. The function returns 0
* on success, -1 if there was not enough space in the uio structure to
* hold the directory entry or an appropriate error code if another
* error happens.
*/
static int
tmpfs_dir_getdotdotdent(struct tmpfs_node *node, struct uio *uio)
{
int error;
struct dirent dent;
TMPFS_VALIDATE_DIR(node);
MPASS(uio->uio_offset == TMPFS_DIRCOOKIE_DOTDOT);
/*
* Return ENOENT if the current node is already removed.
*/
TMPFS_ASSERT_LOCKED(node);
if (node->tn_dir.tn_parent == NULL) {
return (ENOENT);
}
TMPFS_NODE_LOCK(node->tn_dir.tn_parent);
dent.d_fileno = node->tn_dir.tn_parent->tn_id;
TMPFS_NODE_UNLOCK(node->tn_dir.tn_parent);
dent.d_type = DT_DIR;
dent.d_namlen = 2;
dent.d_name[0] = '.';
dent.d_name[1] = '.';
dent.d_name[2] = '\0';
dent.d_reclen = GENERIC_DIRSIZ(&dent);
if (dent.d_reclen > uio->uio_resid)
error = EJUSTRETURN;
else
error = uiomove(&dent, dent.d_reclen, uio);
node->tn_status |= TMPFS_NODE_ACCESSED;
return error;
}
/*
* Helper function for tmpfs_readdir. Returns as much directory entries
* as can fit in the uio space. The read starts at uio->uio_offset.
* The function returns 0 on success, -1 if there was not enough space
* in the uio structure to hold the directory entry or an appropriate
* error code if another error happens.
*/
int
tmpfs_dir_getdents(struct tmpfs_node *node, struct uio *uio, int maxcookies,
u_long *cookies, int *ncookies)
{
struct tmpfs_dir_cursor dc;
struct tmpfs_dirent *de;
off_t off;
int error;
TMPFS_VALIDATE_DIR(node);
off = 0;
/*
* Lookup the node from the current offset. The starting offset of
* 0 will lookup both '.' and '..', and then the first real entry,
* or EOF if there are none. Then find all entries for the dir that
* fit into the buffer. Once no more entries are found (de == NULL),
* the offset is set to TMPFS_DIRCOOKIE_EOF, which will cause the next
* call to return 0.
*/
switch (uio->uio_offset) {
case TMPFS_DIRCOOKIE_DOT:
error = tmpfs_dir_getdotdent(node, uio);
if (error != 0)
return (error);
uio->uio_offset = TMPFS_DIRCOOKIE_DOTDOT;
if (cookies != NULL)
cookies[(*ncookies)++] = off = uio->uio_offset;
/* FALLTHROUGH */
case TMPFS_DIRCOOKIE_DOTDOT:
error = tmpfs_dir_getdotdotdent(node, uio);
if (error != 0)
return (error);
de = tmpfs_dir_first(node, &dc);
uio->uio_offset = tmpfs_dirent_cookie(de);
if (cookies != NULL)
cookies[(*ncookies)++] = off = uio->uio_offset;
/* EOF. */
if (de == NULL)
return (0);
break;
case TMPFS_DIRCOOKIE_EOF:
return (0);
default:
de = tmpfs_dir_lookup_cookie(node, uio->uio_offset, &dc);
if (de == NULL)
return (EINVAL);
if (cookies != NULL)
off = tmpfs_dirent_cookie(de);
}
/* Read as much entries as possible; i.e., until we reach the end of
* the directory or we exhaust uio space. */
do {
struct dirent d;
/* Create a dirent structure representing the current
* tmpfs_node and fill it. */
if (de->td_node == NULL) {
d.d_fileno = 1;
d.d_type = DT_WHT;
} else {
d.d_fileno = de->td_node->tn_id;
switch (de->td_node->tn_type) {
case VBLK:
d.d_type = DT_BLK;
break;
case VCHR:
d.d_type = DT_CHR;
break;
case VDIR:
d.d_type = DT_DIR;
break;
case VFIFO:
d.d_type = DT_FIFO;
break;
case VLNK:
d.d_type = DT_LNK;
break;
case VREG:
d.d_type = DT_REG;
break;
case VSOCK:
d.d_type = DT_SOCK;
break;
default:
panic("tmpfs_dir_getdents: type %p %d",
de->td_node, (int)de->td_node->tn_type);
}
}
d.d_namlen = de->td_namelen;
MPASS(de->td_namelen < sizeof(d.d_name));
(void)memcpy(d.d_name, de->ud.td_name, de->td_namelen);
d.d_name[de->td_namelen] = '\0';
d.d_reclen = GENERIC_DIRSIZ(&d);
/* Stop reading if the directory entry we are treating is
* bigger than the amount of data that can be returned. */
if (d.d_reclen > uio->uio_resid) {
error = EJUSTRETURN;
break;
}
/* Copy the new dirent structure into the output buffer and
* advance pointers. */
error = uiomove(&d, d.d_reclen, uio);
if (error == 0) {
de = tmpfs_dir_next(node, &dc);
if (cookies != NULL) {
off = tmpfs_dirent_cookie(de);
MPASS(*ncookies < maxcookies);
cookies[(*ncookies)++] = off;
}
}
} while (error == 0 && uio->uio_resid > 0 && de != NULL);
/* Skip setting off when using cookies as it is already done above. */
if (cookies == NULL)
off = tmpfs_dirent_cookie(de);
/* Update the offset and cache. */
uio->uio_offset = off;
node->tn_dir.tn_readdir_lastn = off;
node->tn_dir.tn_readdir_lastp = de;
node->tn_status |= TMPFS_NODE_ACCESSED;
return error;
}
int
tmpfs_dir_whiteout_add(struct vnode *dvp, struct componentname *cnp)
{
struct tmpfs_dirent *de;
int error;
error = tmpfs_alloc_dirent(VFS_TO_TMPFS(dvp->v_mount), NULL,
cnp->cn_nameptr, cnp->cn_namelen, &de);
if (error != 0)
return (error);
tmpfs_dir_attach(dvp, de);
return (0);
}
void
tmpfs_dir_whiteout_remove(struct vnode *dvp, struct componentname *cnp)
{
struct tmpfs_dirent *de;
de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp);
MPASS(de != NULL && de->td_node == NULL);
tmpfs_dir_detach(dvp, de);
tmpfs_free_dirent(VFS_TO_TMPFS(dvp->v_mount), de);
}
/*
* Resizes the aobj associated with the regular file pointed to by 'vp' to the
* size 'newsize'. 'vp' must point to a vnode that represents a regular file.
* 'newsize' must be positive.
*
* Returns zero on success or an appropriate error code on failure.
*/
int
tmpfs_reg_resize(struct vnode *vp, off_t newsize, boolean_t ignerr)
{
struct tmpfs_mount *tmp;
struct tmpfs_node *node;
vm_object_t uobj;
vm_page_t m;
vm_pindex_t idx, newpages, oldpages;
off_t oldsize;
int base, rv;
MPASS(vp->v_type == VREG);
MPASS(newsize >= 0);
node = VP_TO_TMPFS_NODE(vp);
uobj = node->tn_reg.tn_aobj;
tmp = VFS_TO_TMPFS(vp->v_mount);
/*
* Convert the old and new sizes to the number of pages needed to
* store them. It may happen that we do not need to do anything
* because the last allocated page can accommodate the change on
* its own.
*/
oldsize = node->tn_size;
oldpages = OFF_TO_IDX(oldsize + PAGE_MASK);
MPASS(oldpages == uobj->size);
newpages = OFF_TO_IDX(newsize + PAGE_MASK);
if (newpages > oldpages &&
tmpfs_pages_check_avail(tmp, newpages - oldpages) == 0)
return (ENOSPC);
VM_OBJECT_WLOCK(uobj);
if (newsize < oldsize) {
/*
* Zero the truncated part of the last page.
*/
base = newsize & PAGE_MASK;
if (base != 0) {
idx = OFF_TO_IDX(newsize);
retry:
m = vm_page_lookup(uobj, idx);
if (m != NULL) {
if (vm_page_sleep_if_busy(m, "tmfssz"))
goto retry;
MPASS(m->valid == VM_PAGE_BITS_ALL);
} else if (vm_pager_has_page(uobj, idx, NULL, NULL)) {
m = vm_page_alloc(uobj, idx, VM_ALLOC_NORMAL);
if (m == NULL) {
VM_OBJECT_WUNLOCK(uobj);
VM_WAIT;
VM_OBJECT_WLOCK(uobj);
goto retry;
} else if (m->valid != VM_PAGE_BITS_ALL)
rv = vm_pager_get_pages(uobj, &m, 1,
NULL, NULL);
else
/* A cached page was reactivated. */
rv = VM_PAGER_OK;
vm_page_lock(m);
if (rv == VM_PAGER_OK) {
vm_page_deactivate(m);
vm_page_unlock(m);
vm_page_xunbusy(m);
} else {
vm_page_free(m);
vm_page_unlock(m);
if (ignerr)
m = NULL;
else {
VM_OBJECT_WUNLOCK(uobj);
return (EIO);
}
}
}
if (m != NULL) {
pmap_zero_page_area(m, base, PAGE_SIZE - base);
vm_page_dirty(m);
vm_pager_page_unswapped(m);
}
}
/*
* Release any swap space and free any whole pages.
*/
if (newpages < oldpages) {
swap_pager_freespace(uobj, newpages, oldpages -
newpages);
vm_object_page_remove(uobj, newpages, 0, 0);
}
}
uobj->size = newpages;
VM_OBJECT_WUNLOCK(uobj);
TMPFS_LOCK(tmp);
tmp->tm_pages_used += (newpages - oldpages);
TMPFS_UNLOCK(tmp);
node->tn_size = newsize;
return (0);
}
void
tmpfs_check_mtime(struct vnode *vp)
{
struct tmpfs_node *node;
struct vm_object *obj;
ASSERT_VOP_ELOCKED(vp, "check_mtime");
if (vp->v_type != VREG)
return;
obj = vp->v_object;
KASSERT((obj->flags & (OBJ_TMPFS_NODE | OBJ_TMPFS)) ==
(OBJ_TMPFS_NODE | OBJ_TMPFS), ("non-tmpfs obj"));
/* unlocked read */
if ((obj->flags & OBJ_TMPFS_DIRTY) != 0) {
VM_OBJECT_WLOCK(obj);
if ((obj->flags & OBJ_TMPFS_DIRTY) != 0) {
obj->flags &= ~OBJ_TMPFS_DIRTY;
node = VP_TO_TMPFS_NODE(vp);
node->tn_status |= TMPFS_NODE_MODIFIED |
TMPFS_NODE_CHANGED;
}
VM_OBJECT_WUNLOCK(obj);
}
}
/*
* Change flags of the given vnode.
* Caller should execute tmpfs_update on vp after a successful execution.
* The vnode must be locked on entry and remain locked on exit.
*/
int
tmpfs_chflags(struct vnode *vp, u_long flags, struct ucred *cred,
struct thread *p)
{
int error;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
if ((flags & ~(SF_APPEND | SF_ARCHIVED | SF_IMMUTABLE | SF_NOUNLINK |
UF_APPEND | UF_ARCHIVE | UF_HIDDEN | UF_IMMUTABLE | UF_NODUMP |
UF_NOUNLINK | UF_OFFLINE | UF_OPAQUE | UF_READONLY | UF_REPARSE |
UF_SPARSE | UF_SYSTEM)) != 0)
return (EOPNOTSUPP);
/* Disallow this operation if the file system is mounted read-only. */
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return EROFS;
/*
* Callers may only modify the file flags on objects they
* have VADMIN rights for.
*/
if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
return (error);
/*
* Unprivileged processes are not permitted to unset system
* flags, or modify flags if any system flags are set.
*/
if (!priv_check_cred(cred, PRIV_VFS_SYSFLAGS, 0)) {
if (node->tn_flags &
(SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND)) {
error = securelevel_gt(cred, 0);
if (error)
return (error);
}
} else {
if (node->tn_flags &
(SF_NOUNLINK | SF_IMMUTABLE | SF_APPEND) ||
((flags ^ node->tn_flags) & SF_SETTABLE))
return (EPERM);
}
node->tn_flags = flags;
node->tn_status |= TMPFS_NODE_CHANGED;
MPASS(VOP_ISLOCKED(vp));
return 0;
}
/*
* Change access mode on the given vnode.
* Caller should execute tmpfs_update on vp after a successful execution.
* The vnode must be locked on entry and remain locked on exit.
*/
int
tmpfs_chmod(struct vnode *vp, mode_t mode, struct ucred *cred, struct thread *p)
{
int error;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
/* Disallow this operation if the file system is mounted read-only. */
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return EROFS;
/* Immutable or append-only files cannot be modified, either. */
if (node->tn_flags & (IMMUTABLE | APPEND))
return EPERM;
/*
* To modify the permissions on a file, must possess VADMIN
* for that file.
*/
if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
return (error);
/*
* Privileged processes may set the sticky bit on non-directories,
* as well as set the setgid bit on a file with a group that the
* process is not a member of.
*/
if (vp->v_type != VDIR && (mode & S_ISTXT)) {
if (priv_check_cred(cred, PRIV_VFS_STICKYFILE, 0))
return (EFTYPE);
}
if (!groupmember(node->tn_gid, cred) && (mode & S_ISGID)) {
error = priv_check_cred(cred, PRIV_VFS_SETGID, 0);
if (error)
return (error);
}
node->tn_mode &= ~ALLPERMS;
node->tn_mode |= mode & ALLPERMS;
node->tn_status |= TMPFS_NODE_CHANGED;
MPASS(VOP_ISLOCKED(vp));
return 0;
}
/*
* Change ownership of the given vnode. At least one of uid or gid must
* be different than VNOVAL. If one is set to that value, the attribute
* is unchanged.
* Caller should execute tmpfs_update on vp after a successful execution.
* The vnode must be locked on entry and remain locked on exit.
*/
int
tmpfs_chown(struct vnode *vp, uid_t uid, gid_t gid, struct ucred *cred,
struct thread *p)
{
int error;
struct tmpfs_node *node;
uid_t ouid;
gid_t ogid;
MPASS(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
/* Assign default values if they are unknown. */
MPASS(uid != VNOVAL || gid != VNOVAL);
if (uid == VNOVAL)
uid = node->tn_uid;
if (gid == VNOVAL)
gid = node->tn_gid;
MPASS(uid != VNOVAL && gid != VNOVAL);
/* Disallow this operation if the file system is mounted read-only. */
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return EROFS;
/* Immutable or append-only files cannot be modified, either. */
if (node->tn_flags & (IMMUTABLE | APPEND))
return EPERM;
/*
* To modify the ownership of a file, must possess VADMIN for that
* file.
*/
if ((error = VOP_ACCESS(vp, VADMIN, cred, p)))
return (error);
/*
* To change the owner of a file, or change the group of a file to a
* group of which we are not a member, the caller must have
* privilege.
*/
if ((uid != node->tn_uid ||
(gid != node->tn_gid && !groupmember(gid, cred))) &&
(error = priv_check_cred(cred, PRIV_VFS_CHOWN, 0)))
return (error);
ogid = node->tn_gid;
ouid = node->tn_uid;
node->tn_uid = uid;
node->tn_gid = gid;
node->tn_status |= TMPFS_NODE_CHANGED;
if ((node->tn_mode & (S_ISUID | S_ISGID)) && (ouid != uid || ogid != gid)) {
if (priv_check_cred(cred, PRIV_VFS_RETAINSUGID, 0))
node->tn_mode &= ~(S_ISUID | S_ISGID);
}
MPASS(VOP_ISLOCKED(vp));
return 0;
}
/*
* Change size of the given vnode.
* Caller should execute tmpfs_update on vp after a successful execution.
* The vnode must be locked on entry and remain locked on exit.
*/
int
tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred,
struct thread *p)
{
int error;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
/* Decide whether this is a valid operation based on the file type. */
error = 0;
switch (vp->v_type) {
case VDIR:
return EISDIR;
case VREG:
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return EROFS;
break;
case VBLK:
/* FALLTHROUGH */
case VCHR:
/* FALLTHROUGH */
case VFIFO:
/* Allow modifications of special files even if in the file
* system is mounted read-only (we are not modifying the
* files themselves, but the objects they represent). */
return 0;
default:
/* Anything else is unsupported. */
return EOPNOTSUPP;
}
/* Immutable or append-only files cannot be modified, either. */
if (node->tn_flags & (IMMUTABLE | APPEND))
return EPERM;
error = tmpfs_truncate(vp, size);
/* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents
* for us, as will update tn_status; no need to do that here. */
MPASS(VOP_ISLOCKED(vp));
return error;
}
/*
* Change access and modification times of the given vnode.
* Caller should execute tmpfs_update on vp after a successful execution.
* The vnode must be locked on entry and remain locked on exit.
*/
int
tmpfs_chtimes(struct vnode *vp, struct vattr *vap,
struct ucred *cred, struct thread *l)
{
int error;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
/* Disallow this operation if the file system is mounted read-only. */
if (vp->v_mount->mnt_flag & MNT_RDONLY)
return EROFS;
/* Immutable or append-only files cannot be modified, either. */
if (node->tn_flags & (IMMUTABLE | APPEND))
return EPERM;
error = vn_utimes_perm(vp, vap, cred, l);
if (error != 0)
return (error);
if (vap->va_atime.tv_sec != VNOVAL)
node->tn_status |= TMPFS_NODE_ACCESSED;
if (vap->va_mtime.tv_sec != VNOVAL)
node->tn_status |= TMPFS_NODE_MODIFIED;
if (vap->va_birthtime.tv_sec != VNOVAL)
node->tn_status |= TMPFS_NODE_MODIFIED;
tmpfs_itimes(vp, &vap->va_atime, &vap->va_mtime);
if (vap->va_birthtime.tv_sec != VNOVAL)
node->tn_birthtime = vap->va_birthtime;
MPASS(VOP_ISLOCKED(vp));
return 0;
}
/* Sync timestamps */
void
tmpfs_itimes(struct vnode *vp, const struct timespec *acc,
const struct timespec *mod)
{
struct tmpfs_node *node;
struct timespec now;
node = VP_TO_TMPFS_NODE(vp);
if ((node->tn_status & (TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
TMPFS_NODE_CHANGED)) == 0)
return;
vfs_timestamp(&now);
if (node->tn_status & TMPFS_NODE_ACCESSED) {
if (acc == NULL)
acc = &now;
node->tn_atime = *acc;
}
if (node->tn_status & TMPFS_NODE_MODIFIED) {
if (mod == NULL)
mod = &now;
node->tn_mtime = *mod;
}
if (node->tn_status & TMPFS_NODE_CHANGED) {
node->tn_ctime = now;
}
node->tn_status &=
~(TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED | TMPFS_NODE_CHANGED);
/* XXX: FIX? The entropy here is desirable, but the harvesting may be expensive */
random_harvest_queue(node, sizeof(*node), 1, RANDOM_FS_ATIME);
}
void
tmpfs_update(struct vnode *vp)
{
tmpfs_itimes(vp, NULL, NULL);
}
int
tmpfs_truncate(struct vnode *vp, off_t length)
{
int error;
struct tmpfs_node *node;
node = VP_TO_TMPFS_NODE(vp);
if (length < 0) {
error = EINVAL;
goto out;
}
if (node->tn_size == length) {
error = 0;
goto out;
}
if (length > VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
return (EFBIG);
error = tmpfs_reg_resize(vp, length, FALSE);
if (error == 0) {
node->tn_status |= TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
}
out:
tmpfs_update(vp);
return error;
}
static __inline int
tmpfs_dirtree_cmp(struct tmpfs_dirent *a, struct tmpfs_dirent *b)
{
if (a->td_hash > b->td_hash)
return (1);
else if (a->td_hash < b->td_hash)
return (-1);
return (0);
}
RB_GENERATE_STATIC(tmpfs_dir, tmpfs_dirent, uh.td_entries, tmpfs_dirtree_cmp);
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