freebsd-dev/sys/fs/tmpfs/tmpfs_vnops.c

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/* $NetBSD: tmpfs_vnops.c,v 1.39 2007/07/23 15:41:01 jmmv Exp $ */
/*-
* Copyright (c) 2005, 2006 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.
*/
/*
* tmpfs vnode interface.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/fcntl.h>
#include <sys/lockf.h>
Switch the vm_object mutex to be a rwlock. This will enable in the future further optimizations where the vm_object lock will be held in read mode most of the time the page cache resident pool of pages are accessed for reading purposes. The change is mostly mechanical but few notes are reported: * The KPI changes as follow: - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK() - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK() - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK() - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED() (in order to avoid visibility of implementation details) - The read-mode operations are added: VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(), VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED() * The vm/vm_pager.h namespace pollution avoidance (forcing requiring sys/mutex.h in consumers directly to cater its inlining functions using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h consumers now must include also sys/rwlock.h. * zfs requires a quite convoluted fix to include FreeBSD rwlocks into the compat layer because the name clash between FreeBSD and solaris versions must be avoided. At this purpose zfs redefines the vm_object locking functions directly, isolating the FreeBSD components in specific compat stubs. The KPI results heavilly broken by this commit. Thirdy part ports must be updated accordingly (I can think off-hand of VirtualBox, for example). Sponsored by: EMC / Isilon storage division Reviewed by: jeff Reviewed by: pjd (ZFS specific review) Discussed with: alc Tested by: pho
2013-03-09 02:32:23 +00:00
#include <sys/lock.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
Switch the vm_object mutex to be a rwlock. This will enable in the future further optimizations where the vm_object lock will be held in read mode most of the time the page cache resident pool of pages are accessed for reading purposes. The change is mostly mechanical but few notes are reported: * The KPI changes as follow: - VM_OBJECT_LOCK() -> VM_OBJECT_WLOCK() - VM_OBJECT_TRYLOCK() -> VM_OBJECT_TRYWLOCK() - VM_OBJECT_UNLOCK() -> VM_OBJECT_WUNLOCK() - VM_OBJECT_LOCK_ASSERT(MA_OWNED) -> VM_OBJECT_ASSERT_WLOCKED() (in order to avoid visibility of implementation details) - The read-mode operations are added: VM_OBJECT_RLOCK(), VM_OBJECT_TRYRLOCK(), VM_OBJECT_RUNLOCK(), VM_OBJECT_ASSERT_RLOCKED(), VM_OBJECT_ASSERT_LOCKED() * The vm/vm_pager.h namespace pollution avoidance (forcing requiring sys/mutex.h in consumers directly to cater its inlining functions using VM_OBJECT_LOCK()) imposes that all the vm/vm_pager.h consumers now must include also sys/rwlock.h. * zfs requires a quite convoluted fix to include FreeBSD rwlocks into the compat layer because the name clash between FreeBSD and solaris versions must be avoided. At this purpose zfs redefines the vm_object locking functions directly, isolating the FreeBSD components in specific compat stubs. The KPI results heavilly broken by this commit. Thirdy part ports must be updated accordingly (I can think off-hand of VirtualBox, for example). Sponsored by: EMC / Isilon storage division Reviewed by: jeff Reviewed by: pjd (ZFS specific review) Discussed with: alc Tested by: pho
2013-03-09 02:32:23 +00:00
#include <sys/rwlock.h>
#include <sys/sched.h>
#include <sys/stat.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_pager.h>
#include <fs/tmpfs/tmpfs_vnops.h>
#include <fs/tmpfs/tmpfs.h>
SYSCTL_DECL(_vfs_tmpfs);
static volatile int tmpfs_rename_restarts;
SYSCTL_INT(_vfs_tmpfs, OID_AUTO, rename_restarts, CTLFLAG_RD,
__DEVOLATILE(int *, &tmpfs_rename_restarts), 0,
"Times rename had to restart due to lock contention");
static int
tmpfs_vn_get_ino_alloc(struct mount *mp, void *arg, int lkflags,
struct vnode **rvp)
{
return (tmpfs_alloc_vp(mp, arg, lkflags, rvp));
}
static int
tmpfs_lookup(struct vop_cachedlookup_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode **vpp = v->a_vpp;
struct componentname *cnp = v->a_cnp;
struct tmpfs_dirent *de;
struct tmpfs_node *dnode;
int error;
dnode = VP_TO_TMPFS_DIR(dvp);
*vpp = NULLVP;
/* Check accessibility of requested node as a first step. */
error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_thread);
if (error != 0)
goto out;
/* We cannot be requesting the parent directory of the root node. */
MPASS(IMPLIES(dnode->tn_type == VDIR &&
dnode->tn_dir.tn_parent == dnode,
!(cnp->cn_flags & ISDOTDOT)));
TMPFS_ASSERT_LOCKED(dnode);
if (dnode->tn_dir.tn_parent == NULL) {
error = ENOENT;
goto out;
}
if (cnp->cn_flags & ISDOTDOT) {
error = vn_vget_ino_gen(dvp, tmpfs_vn_get_ino_alloc,
dnode->tn_dir.tn_parent, cnp->cn_lkflags, vpp);
if (error != 0)
goto out;
} else if (cnp->cn_namelen == 1 && cnp->cn_nameptr[0] == '.') {
VREF(dvp);
*vpp = dvp;
error = 0;
} else {
de = tmpfs_dir_lookup(dnode, NULL, cnp);
if (de != NULL && de->td_node == NULL)
cnp->cn_flags |= ISWHITEOUT;
if (de == NULL || de->td_node == NULL) {
/* The entry was not found in the directory.
* This is OK if we are creating or renaming an
* entry and are working on the last component of
* the path name. */
if ((cnp->cn_flags & ISLASTCN) &&
(cnp->cn_nameiop == CREATE || \
cnp->cn_nameiop == RENAME ||
(cnp->cn_nameiop == DELETE &&
cnp->cn_flags & DOWHITEOUT &&
cnp->cn_flags & ISWHITEOUT))) {
error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred,
cnp->cn_thread);
if (error != 0)
goto out;
/* Keep the component name in the buffer for
* future uses. */
cnp->cn_flags |= SAVENAME;
error = EJUSTRETURN;
} else
error = ENOENT;
} else {
struct tmpfs_node *tnode;
/* The entry was found, so get its associated
* tmpfs_node. */
tnode = de->td_node;
/* If we are not at the last path component and
* found a non-directory or non-link entry (which
* may itself be pointing to a directory), raise
* an error. */
if ((tnode->tn_type != VDIR &&
tnode->tn_type != VLNK) &&
!(cnp->cn_flags & ISLASTCN)) {
error = ENOTDIR;
goto out;
}
/* If we are deleting or renaming the entry, keep
* track of its tmpfs_dirent so that it can be
* easily deleted later. */
if ((cnp->cn_flags & ISLASTCN) &&
(cnp->cn_nameiop == DELETE ||
cnp->cn_nameiop == RENAME)) {
error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred,
cnp->cn_thread);
if (error != 0)
goto out;
/* Allocate a new vnode on the matching entry. */
error = tmpfs_alloc_vp(dvp->v_mount, tnode,
cnp->cn_lkflags, vpp);
if (error != 0)
goto out;
if ((dnode->tn_mode & S_ISTXT) &&
VOP_ACCESS(dvp, VADMIN, cnp->cn_cred, cnp->cn_thread) &&
VOP_ACCESS(*vpp, VADMIN, cnp->cn_cred, cnp->cn_thread)) {
error = EPERM;
vput(*vpp);
*vpp = NULL;
goto out;
}
cnp->cn_flags |= SAVENAME;
} else {
error = tmpfs_alloc_vp(dvp->v_mount, tnode,
cnp->cn_lkflags, vpp);
if (error != 0)
goto out;
}
}
}
/* Store the result of this lookup in the cache. Avoid this if the
* request was for creation, as it does not improve timings on
* emprical tests. */
if ((cnp->cn_flags & MAKEENTRY) && cnp->cn_nameiop != CREATE)
cache_enter(dvp, *vpp, cnp);
out:
/* If there were no errors, *vpp cannot be null and it must be
* locked. */
MPASS(IFF(error == 0, *vpp != NULLVP && VOP_ISLOCKED(*vpp)));
return error;
}
static int
tmpfs_create(struct vop_create_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode **vpp = v->a_vpp;
struct componentname *cnp = v->a_cnp;
struct vattr *vap = v->a_vap;
MPASS(vap->va_type == VREG || vap->va_type == VSOCK);
return tmpfs_alloc_file(dvp, vpp, vap, cnp, NULL);
}
static int
tmpfs_mknod(struct vop_mknod_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode **vpp = v->a_vpp;
struct componentname *cnp = v->a_cnp;
struct vattr *vap = v->a_vap;
if (vap->va_type != VBLK && vap->va_type != VCHR &&
vap->va_type != VFIFO)
return EINVAL;
return tmpfs_alloc_file(dvp, vpp, vap, cnp, NULL);
}
static int
tmpfs_open(struct vop_open_args *v)
{
struct vnode *vp = v->a_vp;
int mode = v->a_mode;
int error;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
/* The file is still active but all its names have been removed
* (e.g. by a "rmdir $(pwd)"). It cannot be opened any more as
* it is about to die. */
if (node->tn_links < 1)
return (ENOENT);
/* If the file is marked append-only, deny write requests. */
if (node->tn_flags & APPEND && (mode & (FWRITE | O_APPEND)) == FWRITE)
error = EPERM;
else {
error = 0;
/* For regular files, the call below is nop. */
KASSERT(vp->v_type != VREG || (node->tn_reg.tn_aobj->flags &
OBJ_DEAD) == 0, ("dead object"));
vnode_create_vobject(vp, node->tn_size, v->a_td);
}
MPASS(VOP_ISLOCKED(vp));
return error;
}
static int
tmpfs_close(struct vop_close_args *v)
{
struct vnode *vp = v->a_vp;
/* Update node times. */
tmpfs_update(vp);
return (0);
}
int
tmpfs_access(struct vop_access_args *v)
{
struct vnode *vp = v->a_vp;
accmode_t accmode = v->a_accmode;
struct ucred *cred = v->a_cred;
int error;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(vp));
node = VP_TO_TMPFS_NODE(vp);
switch (vp->v_type) {
case VDIR:
/* FALLTHROUGH */
case VLNK:
/* FALLTHROUGH */
case VREG:
if (accmode & VWRITE && vp->v_mount->mnt_flag & MNT_RDONLY) {
error = EROFS;
goto out;
}
break;
case VBLK:
/* FALLTHROUGH */
case VCHR:
/* FALLTHROUGH */
case VSOCK:
/* FALLTHROUGH */
case VFIFO:
break;
default:
error = EINVAL;
goto out;
}
if (accmode & VWRITE && node->tn_flags & IMMUTABLE) {
error = EPERM;
goto out;
}
error = vaccess(vp->v_type, node->tn_mode, node->tn_uid,
node->tn_gid, accmode, cred, NULL);
out:
MPASS(VOP_ISLOCKED(vp));
return error;
}
int
tmpfs_getattr(struct vop_getattr_args *v)
{
struct vnode *vp = v->a_vp;
struct vattr *vap = v->a_vap;
struct tmpfs_node *node;
node = VP_TO_TMPFS_NODE(vp);
tmpfs_update(vp);
vap->va_type = vp->v_type;
vap->va_mode = node->tn_mode;
vap->va_nlink = node->tn_links;
vap->va_uid = node->tn_uid;
vap->va_gid = node->tn_gid;
vap->va_fsid = vp->v_mount->mnt_stat.f_fsid.val[0];
vap->va_fileid = node->tn_id;
vap->va_size = node->tn_size;
vap->va_blocksize = PAGE_SIZE;
vap->va_atime = node->tn_atime;
vap->va_mtime = node->tn_mtime;
vap->va_ctime = node->tn_ctime;
vap->va_birthtime = node->tn_birthtime;
vap->va_gen = node->tn_gen;
vap->va_flags = node->tn_flags;
vap->va_rdev = (vp->v_type == VBLK || vp->v_type == VCHR) ?
node->tn_rdev : NODEV;
vap->va_bytes = round_page(node->tn_size);
vap->va_filerev = 0;
return 0;
}
int
tmpfs_setattr(struct vop_setattr_args *v)
{
struct vnode *vp = v->a_vp;
struct vattr *vap = v->a_vap;
struct ucred *cred = v->a_cred;
struct thread *td = curthread;
int error;
MPASS(VOP_ISLOCKED(vp));
error = 0;
/* Abort if any unsettable attribute is given. */
if (vap->va_type != VNON ||
vap->va_nlink != VNOVAL ||
vap->va_fsid != VNOVAL ||
vap->va_fileid != VNOVAL ||
vap->va_blocksize != VNOVAL ||
vap->va_gen != VNOVAL ||
vap->va_rdev != VNOVAL ||
vap->va_bytes != VNOVAL)
error = EINVAL;
if (error == 0 && (vap->va_flags != VNOVAL))
error = tmpfs_chflags(vp, vap->va_flags, cred, td);
if (error == 0 && (vap->va_size != VNOVAL))
error = tmpfs_chsize(vp, vap->va_size, cred, td);
if (error == 0 && (vap->va_uid != VNOVAL || vap->va_gid != VNOVAL))
error = tmpfs_chown(vp, vap->va_uid, vap->va_gid, cred, td);
if (error == 0 && (vap->va_mode != (mode_t)VNOVAL))
error = tmpfs_chmod(vp, vap->va_mode, cred, td);
if (error == 0 && ((vap->va_atime.tv_sec != VNOVAL &&
vap->va_atime.tv_nsec != VNOVAL) ||
(vap->va_mtime.tv_sec != VNOVAL &&
vap->va_mtime.tv_nsec != VNOVAL) ||
(vap->va_birthtime.tv_sec != VNOVAL &&
vap->va_birthtime.tv_nsec != VNOVAL)))
error = tmpfs_chtimes(vp, vap, cred, td);
/* Update the node times. We give preference to the error codes
* generated by this function rather than the ones that may arise
* from tmpfs_update. */
tmpfs_update(vp);
MPASS(VOP_ISLOCKED(vp));
return error;
}
static int
tmpfs_read(struct vop_read_args *v)
{
struct vnode *vp;
struct uio *uio;
struct tmpfs_node *node;
vp = v->a_vp;
if (vp->v_type != VREG)
return (EISDIR);
uio = v->a_uio;
if (uio->uio_offset < 0)
return (EINVAL);
node = VP_TO_TMPFS_NODE(vp);
node->tn_status |= TMPFS_NODE_ACCESSED;
return (uiomove_object(node->tn_reg.tn_aobj, node->tn_size, uio));
}
static int
tmpfs_write(struct vop_write_args *v)
{
struct vnode *vp;
struct uio *uio;
struct tmpfs_node *node;
off_t oldsize;
int error, ioflag;
boolean_t extended;
vp = v->a_vp;
uio = v->a_uio;
ioflag = v->a_ioflag;
error = 0;
node = VP_TO_TMPFS_NODE(vp);
oldsize = node->tn_size;
if (uio->uio_offset < 0 || vp->v_type != VREG)
return (EINVAL);
if (uio->uio_resid == 0)
return (0);
if (ioflag & IO_APPEND)
uio->uio_offset = node->tn_size;
if (uio->uio_offset + uio->uio_resid >
VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
return (EFBIG);
if (vn_rlimit_fsize(vp, uio, uio->uio_td))
return (EFBIG);
extended = uio->uio_offset + uio->uio_resid > node->tn_size;
if (extended) {
error = tmpfs_reg_resize(vp, uio->uio_offset + uio->uio_resid,
FALSE);
if (error != 0)
goto out;
}
error = uiomove_object(node->tn_reg.tn_aobj, node->tn_size, uio);
node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
(extended ? TMPFS_NODE_CHANGED : 0);
if (node->tn_mode & (S_ISUID | S_ISGID)) {
if (priv_check_cred(v->a_cred, PRIV_VFS_RETAINSUGID, 0))
node->tn_mode &= ~(S_ISUID | S_ISGID);
}
if (error != 0)
(void)tmpfs_reg_resize(vp, oldsize, TRUE);
out:
MPASS(IMPLIES(error == 0, uio->uio_resid == 0));
MPASS(IMPLIES(error != 0, oldsize == node->tn_size));
return (error);
}
static int
tmpfs_fsync(struct vop_fsync_args *v)
{
struct vnode *vp = v->a_vp;
MPASS(VOP_ISLOCKED(vp));
tmpfs_update(vp);
return 0;
}
static int
tmpfs_remove(struct vop_remove_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode *vp = v->a_vp;
int error;
struct tmpfs_dirent *de;
struct tmpfs_mount *tmp;
struct tmpfs_node *dnode;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(dvp));
MPASS(VOP_ISLOCKED(vp));
if (vp->v_type == VDIR) {
error = EISDIR;
goto out;
}
dnode = VP_TO_TMPFS_DIR(dvp);
node = VP_TO_TMPFS_NODE(vp);
tmp = VFS_TO_TMPFS(vp->v_mount);
de = tmpfs_dir_lookup(dnode, node, v->a_cnp);
MPASS(de != NULL);
/* Files marked as immutable or append-only cannot be deleted. */
if ((node->tn_flags & (IMMUTABLE | APPEND | NOUNLINK)) ||
(dnode->tn_flags & APPEND)) {
error = EPERM;
goto out;
}
/* Remove the entry from the directory; as it is a file, we do not
* have to change the number of hard links of the directory. */
tmpfs_dir_detach(dvp, de);
if (v->a_cnp->cn_flags & DOWHITEOUT)
tmpfs_dir_whiteout_add(dvp, v->a_cnp);
/* Free the directory entry we just deleted. Note that the node
* referred by it will not be removed until the vnode is really
* reclaimed. */
tmpfs_free_dirent(tmp, de);
node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED;
error = 0;
out:
return error;
}
static int
tmpfs_link(struct vop_link_args *v)
{
struct vnode *dvp = v->a_tdvp;
struct vnode *vp = v->a_vp;
struct componentname *cnp = v->a_cnp;
int error;
struct tmpfs_dirent *de;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(dvp));
MPASS(cnp->cn_flags & HASBUF);
MPASS(dvp != vp); /* XXX When can this be false? */
node = VP_TO_TMPFS_NODE(vp);
/* Ensure that we do not overflow the maximum number of links imposed
* by the system. */
MPASS(node->tn_links <= LINK_MAX);
if (node->tn_links == LINK_MAX) {
error = EMLINK;
goto out;
}
/* We cannot create links of files marked immutable or append-only. */
if (node->tn_flags & (IMMUTABLE | APPEND)) {
error = EPERM;
goto out;
}
/* Allocate a new directory entry to represent the node. */
error = tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), node,
cnp->cn_nameptr, cnp->cn_namelen, &de);
if (error != 0)
goto out;
/* Insert the new directory entry into the appropriate directory. */
if (cnp->cn_flags & ISWHITEOUT)
tmpfs_dir_whiteout_remove(dvp, cnp);
tmpfs_dir_attach(dvp, de);
/* vp link count has changed, so update node times. */
node->tn_status |= TMPFS_NODE_CHANGED;
tmpfs_update(vp);
error = 0;
out:
return error;
}
/*
* We acquire all but fdvp locks using non-blocking acquisitions. If we
* fail to acquire any lock in the path we will drop all held locks,
* acquire the new lock in a blocking fashion, and then release it and
* restart the rename. This acquire/release step ensures that we do not
* spin on a lock waiting for release. On error release all vnode locks
* and decrement references the way tmpfs_rename() would do.
*/
static int
tmpfs_rename_relock(struct vnode *fdvp, struct vnode **fvpp,
struct vnode *tdvp, struct vnode **tvpp,
struct componentname *fcnp, struct componentname *tcnp)
{
struct vnode *nvp;
struct mount *mp;
struct tmpfs_dirent *de;
int error, restarts = 0;
VOP_UNLOCK(tdvp, 0);
if (*tvpp != NULL && *tvpp != tdvp)
VOP_UNLOCK(*tvpp, 0);
mp = fdvp->v_mount;
relock:
restarts += 1;
error = vn_lock(fdvp, LK_EXCLUSIVE);
if (error)
goto releout;
if (vn_lock(tdvp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
VOP_UNLOCK(fdvp, 0);
error = vn_lock(tdvp, LK_EXCLUSIVE);
if (error)
goto releout;
VOP_UNLOCK(tdvp, 0);
goto relock;
}
/*
* Re-resolve fvp to be certain it still exists and fetch the
* correct vnode.
*/
de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(fdvp), NULL, fcnp);
if (de == NULL) {
VOP_UNLOCK(fdvp, 0);
VOP_UNLOCK(tdvp, 0);
if ((fcnp->cn_flags & ISDOTDOT) != 0 ||
(fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.'))
error = EINVAL;
else
error = ENOENT;
goto releout;
}
error = tmpfs_alloc_vp(mp, de->td_node, LK_EXCLUSIVE | LK_NOWAIT, &nvp);
if (error != 0) {
VOP_UNLOCK(fdvp, 0);
VOP_UNLOCK(tdvp, 0);
if (error != EBUSY)
goto releout;
error = tmpfs_alloc_vp(mp, de->td_node, LK_EXCLUSIVE, &nvp);
if (error != 0)
goto releout;
VOP_UNLOCK(nvp, 0);
/*
* Concurrent rename race.
*/
if (nvp == tdvp) {
vrele(nvp);
error = EINVAL;
goto releout;
}
vrele(*fvpp);
*fvpp = nvp;
goto relock;
}
vrele(*fvpp);
*fvpp = nvp;
VOP_UNLOCK(*fvpp, 0);
/*
* Re-resolve tvp and acquire the vnode lock if present.
*/
de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(tdvp), NULL, tcnp);
/*
* If tvp disappeared we just carry on.
*/
if (de == NULL && *tvpp != NULL) {
vrele(*tvpp);
*tvpp = NULL;
}
/*
* Get the tvp ino if the lookup succeeded. We may have to restart
* if the non-blocking acquire fails.
*/
if (de != NULL) {
nvp = NULL;
error = tmpfs_alloc_vp(mp, de->td_node,
LK_EXCLUSIVE | LK_NOWAIT, &nvp);
if (*tvpp != NULL)
vrele(*tvpp);
*tvpp = nvp;
if (error != 0) {
VOP_UNLOCK(fdvp, 0);
VOP_UNLOCK(tdvp, 0);
if (error != EBUSY)
goto releout;
error = tmpfs_alloc_vp(mp, de->td_node, LK_EXCLUSIVE,
&nvp);
if (error != 0)
goto releout;
VOP_UNLOCK(nvp, 0);
/*
* fdvp contains fvp, thus tvp (=fdvp) is not empty.
*/
if (nvp == fdvp) {
error = ENOTEMPTY;
goto releout;
}
goto relock;
}
}
tmpfs_rename_restarts += restarts;
return (0);
releout:
vrele(fdvp);
vrele(*fvpp);
vrele(tdvp);
if (*tvpp != NULL)
vrele(*tvpp);
tmpfs_rename_restarts += restarts;
return (error);
}
static int
tmpfs_rename(struct vop_rename_args *v)
{
struct vnode *fdvp = v->a_fdvp;
struct vnode *fvp = v->a_fvp;
struct componentname *fcnp = v->a_fcnp;
struct vnode *tdvp = v->a_tdvp;
struct vnode *tvp = v->a_tvp;
struct componentname *tcnp = v->a_tcnp;
struct mount *mp = NULL;
char *newname;
int error;
struct tmpfs_dirent *de;
struct tmpfs_mount *tmp;
struct tmpfs_node *fdnode;
struct tmpfs_node *fnode;
struct tmpfs_node *tnode;
struct tmpfs_node *tdnode;
MPASS(VOP_ISLOCKED(tdvp));
MPASS(IMPLIES(tvp != NULL, VOP_ISLOCKED(tvp)));
MPASS(fcnp->cn_flags & HASBUF);
MPASS(tcnp->cn_flags & HASBUF);
/* Disallow cross-device renames.
* XXX Why isn't this done by the caller? */
if (fvp->v_mount != tdvp->v_mount ||
(tvp != NULL && fvp->v_mount != tvp->v_mount)) {
error = EXDEV;
goto out;
}
/* If source and target are the same file, there is nothing to do. */
if (fvp == tvp) {
error = 0;
goto out;
}
/* If we need to move the directory between entries, lock the
* source so that we can safely operate on it. */
if (fdvp != tdvp && fdvp != tvp) {
if (vn_lock(fdvp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
mp = tdvp->v_mount;
error = vfs_busy(mp, 0);
if (error != 0) {
mp = NULL;
goto out;
}
error = tmpfs_rename_relock(fdvp, &fvp, tdvp, &tvp,
fcnp, tcnp);
if (error != 0) {
vfs_unbusy(mp);
return (error);
}
ASSERT_VOP_ELOCKED(fdvp,
"tmpfs_rename: fdvp not locked");
ASSERT_VOP_ELOCKED(tdvp,
"tmpfs_rename: tdvp not locked");
if (tvp != NULL)
ASSERT_VOP_ELOCKED(tvp,
"tmpfs_rename: tvp not locked");
if (fvp == tvp) {
error = 0;
goto out_locked;
}
}
}
tmp = VFS_TO_TMPFS(tdvp->v_mount);
tdnode = VP_TO_TMPFS_DIR(tdvp);
tnode = (tvp == NULL) ? NULL : VP_TO_TMPFS_NODE(tvp);
fdnode = VP_TO_TMPFS_DIR(fdvp);
fnode = VP_TO_TMPFS_NODE(fvp);
de = tmpfs_dir_lookup(fdnode, fnode, fcnp);
/* Entry can disappear before we lock fdvp,
* also avoid manipulating '.' and '..' entries. */
if (de == NULL) {
if ((fcnp->cn_flags & ISDOTDOT) != 0 ||
(fcnp->cn_namelen == 1 && fcnp->cn_nameptr[0] == '.'))
error = EINVAL;
else
error = ENOENT;
goto out_locked;
}
MPASS(de->td_node == fnode);
/* If re-naming a directory to another preexisting directory
* ensure that the target directory is empty so that its
* removal causes no side effects.
* Kern_rename gurantees the destination to be a directory
* if the source is one. */
if (tvp != NULL) {
MPASS(tnode != NULL);
if ((tnode->tn_flags & (NOUNLINK | IMMUTABLE | APPEND)) ||
(tdnode->tn_flags & (APPEND | IMMUTABLE))) {
error = EPERM;
goto out_locked;
}
if (fnode->tn_type == VDIR && tnode->tn_type == VDIR) {
if (tnode->tn_size > 0) {
error = ENOTEMPTY;
goto out_locked;
}
} else if (fnode->tn_type == VDIR && tnode->tn_type != VDIR) {
error = ENOTDIR;
goto out_locked;
} else if (fnode->tn_type != VDIR && tnode->tn_type == VDIR) {
error = EISDIR;
goto out_locked;
} else {
MPASS(fnode->tn_type != VDIR &&
tnode->tn_type != VDIR);
}
}
if ((fnode->tn_flags & (NOUNLINK | IMMUTABLE | APPEND))
|| (fdnode->tn_flags & (APPEND | IMMUTABLE))) {
error = EPERM;
goto out_locked;
}
/* Ensure that we have enough memory to hold the new name, if it
* has to be changed. */
if (fcnp->cn_namelen != tcnp->cn_namelen ||
bcmp(fcnp->cn_nameptr, tcnp->cn_nameptr, fcnp->cn_namelen) != 0) {
newname = malloc(tcnp->cn_namelen, M_TMPFSNAME, M_WAITOK);
} else
newname = NULL;
/* If the node is being moved to another directory, we have to do
* the move. */
if (fdnode != tdnode) {
/* In case we are moving a directory, we have to adjust its
* parent to point to the new parent. */
if (de->td_node->tn_type == VDIR) {
struct tmpfs_node *n;
/* Ensure the target directory is not a child of the
* directory being moved. Otherwise, we'd end up
* with stale nodes. */
n = tdnode;
/* TMPFS_LOCK garanties that no nodes are freed while
* traversing the list. Nodes can only be marked as
* removed: tn_parent == NULL. */
TMPFS_LOCK(tmp);
TMPFS_NODE_LOCK(n);
while (n != n->tn_dir.tn_parent) {
struct tmpfs_node *parent;
if (n == fnode) {
TMPFS_NODE_UNLOCK(n);
TMPFS_UNLOCK(tmp);
error = EINVAL;
if (newname != NULL)
free(newname, M_TMPFSNAME);
goto out_locked;
}
parent = n->tn_dir.tn_parent;
TMPFS_NODE_UNLOCK(n);
if (parent == NULL) {
n = NULL;
break;
}
TMPFS_NODE_LOCK(parent);
if (parent->tn_dir.tn_parent == NULL) {
TMPFS_NODE_UNLOCK(parent);
n = NULL;
break;
}
n = parent;
}
TMPFS_UNLOCK(tmp);
if (n == NULL) {
error = EINVAL;
if (newname != NULL)
free(newname, M_TMPFSNAME);
goto out_locked;
}
TMPFS_NODE_UNLOCK(n);
/* Adjust the parent pointer. */
TMPFS_VALIDATE_DIR(fnode);
TMPFS_NODE_LOCK(de->td_node);
de->td_node->tn_dir.tn_parent = tdnode;
TMPFS_NODE_UNLOCK(de->td_node);
/* As a result of changing the target of the '..'
* entry, the link count of the source and target
* directories has to be adjusted. */
TMPFS_NODE_LOCK(tdnode);
TMPFS_ASSERT_LOCKED(tdnode);
tdnode->tn_links++;
TMPFS_NODE_UNLOCK(tdnode);
TMPFS_NODE_LOCK(fdnode);
TMPFS_ASSERT_LOCKED(fdnode);
fdnode->tn_links--;
TMPFS_NODE_UNLOCK(fdnode);
}
}
/* Do the move: just remove the entry from the source directory
* and insert it into the target one. */
tmpfs_dir_detach(fdvp, de);
if (fcnp->cn_flags & DOWHITEOUT)
tmpfs_dir_whiteout_add(fdvp, fcnp);
if (tcnp->cn_flags & ISWHITEOUT)
tmpfs_dir_whiteout_remove(tdvp, tcnp);
/* If the name has changed, we need to make it effective by changing
* it in the directory entry. */
if (newname != NULL) {
MPASS(tcnp->cn_namelen <= MAXNAMLEN);
free(de->ud.td_name, M_TMPFSNAME);
de->ud.td_name = newname;
tmpfs_dirent_init(de, tcnp->cn_nameptr, tcnp->cn_namelen);
fnode->tn_status |= TMPFS_NODE_CHANGED;
tdnode->tn_status |= TMPFS_NODE_MODIFIED;
}
/* If we are overwriting an entry, we have to remove the old one
* from the target directory. */
if (tvp != NULL) {
struct tmpfs_dirent *tde;
/* Remove the old entry from the target directory. */
tde = tmpfs_dir_lookup(tdnode, tnode, tcnp);
tmpfs_dir_detach(tdvp, tde);
/* Free the directory entry we just deleted. Note that the
* node referred by it will not be removed until the vnode is
* really reclaimed. */
tmpfs_free_dirent(VFS_TO_TMPFS(tvp->v_mount), tde);
}
tmpfs_dir_attach(tdvp, de);
cache_purge(fvp);
if (tvp != NULL)
cache_purge(tvp);
cache_purge_negative(tdvp);
error = 0;
out_locked:
if (fdvp != tdvp && fdvp != tvp)
VOP_UNLOCK(fdvp, 0);
out:
/* Release target nodes. */
/* XXX: I don't understand when tdvp can be the same as tvp, but
* other code takes care of this... */
if (tdvp == tvp)
vrele(tdvp);
else
vput(tdvp);
if (tvp != NULL)
vput(tvp);
/* Release source nodes. */
vrele(fdvp);
vrele(fvp);
if (mp != NULL)
vfs_unbusy(mp);
return error;
}
static int
tmpfs_mkdir(struct vop_mkdir_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode **vpp = v->a_vpp;
struct componentname *cnp = v->a_cnp;
struct vattr *vap = v->a_vap;
MPASS(vap->va_type == VDIR);
return tmpfs_alloc_file(dvp, vpp, vap, cnp, NULL);
}
static int
tmpfs_rmdir(struct vop_rmdir_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode *vp = v->a_vp;
int error;
struct tmpfs_dirent *de;
struct tmpfs_mount *tmp;
struct tmpfs_node *dnode;
struct tmpfs_node *node;
MPASS(VOP_ISLOCKED(dvp));
MPASS(VOP_ISLOCKED(vp));
tmp = VFS_TO_TMPFS(dvp->v_mount);
dnode = VP_TO_TMPFS_DIR(dvp);
node = VP_TO_TMPFS_DIR(vp);
/* Directories with more than two entries ('.' and '..') cannot be
* removed. */
if (node->tn_size > 0) {
error = ENOTEMPTY;
goto out;
}
if ((dnode->tn_flags & APPEND)
|| (node->tn_flags & (NOUNLINK | IMMUTABLE | APPEND))) {
error = EPERM;
goto out;
}
/* This invariant holds only if we are not trying to remove "..".
* We checked for that above so this is safe now. */
MPASS(node->tn_dir.tn_parent == dnode);
/* Get the directory entry associated with node (vp). This was
* filled by tmpfs_lookup while looking up the entry. */
de = tmpfs_dir_lookup(dnode, node, v->a_cnp);
MPASS(TMPFS_DIRENT_MATCHES(de,
v->a_cnp->cn_nameptr,
v->a_cnp->cn_namelen));
/* Check flags to see if we are allowed to remove the directory. */
if (dnode->tn_flags & APPEND
|| node->tn_flags & (NOUNLINK | IMMUTABLE | APPEND)) {
error = EPERM;
goto out;
}
/* Detach the directory entry from the directory (dnode). */
tmpfs_dir_detach(dvp, de);
if (v->a_cnp->cn_flags & DOWHITEOUT)
tmpfs_dir_whiteout_add(dvp, v->a_cnp);
/* No vnode should be allocated for this entry from this point */
TMPFS_NODE_LOCK(node);
TMPFS_ASSERT_ELOCKED(node);
node->tn_links--;
node->tn_dir.tn_parent = NULL;
node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_CHANGED | \
TMPFS_NODE_MODIFIED;
TMPFS_NODE_UNLOCK(node);
TMPFS_NODE_LOCK(dnode);
TMPFS_ASSERT_ELOCKED(dnode);
dnode->tn_links--;
dnode->tn_status |= TMPFS_NODE_ACCESSED | \
TMPFS_NODE_CHANGED | TMPFS_NODE_MODIFIED;
TMPFS_NODE_UNLOCK(dnode);
cache_purge(dvp);
cache_purge(vp);
/* Free the directory entry we just deleted. Note that the node
* referred by it will not be removed until the vnode is really
* reclaimed. */
tmpfs_free_dirent(tmp, de);
/* Release the deleted vnode (will destroy the node, notify
* interested parties and clean it from the cache). */
dnode->tn_status |= TMPFS_NODE_CHANGED;
tmpfs_update(dvp);
error = 0;
out:
return error;
}
static int
tmpfs_symlink(struct vop_symlink_args *v)
{
struct vnode *dvp = v->a_dvp;
struct vnode **vpp = v->a_vpp;
struct componentname *cnp = v->a_cnp;
struct vattr *vap = v->a_vap;
char *target = v->a_target;
#ifdef notyet /* XXX FreeBSD BUG: kern_symlink is not setting VLNK */
MPASS(vap->va_type == VLNK);
#else
vap->va_type = VLNK;
#endif
return tmpfs_alloc_file(dvp, vpp, vap, cnp, target);
}
static int
tmpfs_readdir(struct vop_readdir_args *v)
{
struct vnode *vp = v->a_vp;
struct uio *uio = v->a_uio;
int *eofflag = v->a_eofflag;
u_long **cookies = v->a_cookies;
int *ncookies = v->a_ncookies;
int error;
ssize_t startresid;
int maxcookies;
struct tmpfs_node *node;
/* This operation only makes sense on directory nodes. */
if (vp->v_type != VDIR)
return ENOTDIR;
maxcookies = 0;
node = VP_TO_TMPFS_DIR(vp);
startresid = uio->uio_resid;
/* Allocate cookies for NFS and compat modules. */
if (cookies != NULL && ncookies != NULL) {
maxcookies = howmany(node->tn_size,
sizeof(struct tmpfs_dirent)) + 2;
*cookies = malloc(maxcookies * sizeof(**cookies), M_TEMP,
M_WAITOK);
*ncookies = 0;
}
if (cookies == NULL)
error = tmpfs_dir_getdents(node, uio, 0, NULL, NULL);
else
error = tmpfs_dir_getdents(node, uio, maxcookies, *cookies,
ncookies);
/* Buffer was filled without hitting EOF. */
if (error == EJUSTRETURN)
error = (uio->uio_resid != startresid) ? 0 : EINVAL;
if (error != 0 && cookies != NULL)
free(*cookies, M_TEMP);
if (eofflag != NULL)
*eofflag =
(error == 0 && uio->uio_offset == TMPFS_DIRCOOKIE_EOF);
return error;
}
static int
tmpfs_readlink(struct vop_readlink_args *v)
{
struct vnode *vp = v->a_vp;
struct uio *uio = v->a_uio;
int error;
struct tmpfs_node *node;
MPASS(uio->uio_offset == 0);
MPASS(vp->v_type == VLNK);
node = VP_TO_TMPFS_NODE(vp);
error = uiomove(node->tn_link, MIN(node->tn_size, uio->uio_resid),
uio);
node->tn_status |= TMPFS_NODE_ACCESSED;
return error;
}
static int
tmpfs_inactive(struct vop_inactive_args *v)
{
struct vnode *vp = v->a_vp;
struct tmpfs_node *node;
node = VP_TO_TMPFS_NODE(vp);
if (node->tn_links == 0)
vrecycle(vp);
return 0;
}
int
tmpfs_reclaim(struct vop_reclaim_args *v)
{
struct vnode *vp = v->a_vp;
struct tmpfs_mount *tmp;
struct tmpfs_node *node;
node = VP_TO_TMPFS_NODE(vp);
tmp = VFS_TO_TMPFS(vp->v_mount);
if (vp->v_type == VREG)
tmpfs_destroy_vobject(vp, node->tn_reg.tn_aobj);
else
vnode_destroy_vobject(vp);
vp->v_object = NULL;
cache_purge(vp);
TMPFS_NODE_LOCK(node);
TMPFS_ASSERT_ELOCKED(node);
tmpfs_free_vp(vp);
/* If the node referenced by this vnode was deleted by the user,
* we must free its associated data structures (now that the vnode
* is being reclaimed). */
if (node->tn_links == 0 &&
(node->tn_vpstate & TMPFS_VNODE_ALLOCATING) == 0) {
node->tn_vpstate = TMPFS_VNODE_DOOMED;
TMPFS_NODE_UNLOCK(node);
tmpfs_free_node(tmp, node);
} else
TMPFS_NODE_UNLOCK(node);
MPASS(vp->v_data == NULL);
return 0;
}
static int
tmpfs_print(struct vop_print_args *v)
{
struct vnode *vp = v->a_vp;
struct tmpfs_node *node;
node = VP_TO_TMPFS_NODE(vp);
printf("tag VT_TMPFS, tmpfs_node %p, flags 0x%lx, links %d\n",
node, node->tn_flags, node->tn_links);
printf("\tmode 0%o, owner %d, group %d, size %jd, status 0x%x\n",
node->tn_mode, node->tn_uid, node->tn_gid,
(intmax_t)node->tn_size, node->tn_status);
if (vp->v_type == VFIFO)
fifo_printinfo(vp);
printf("\n");
return 0;
}
static int
tmpfs_pathconf(struct vop_pathconf_args *v)
{
int name = v->a_name;
register_t *retval = v->a_retval;
int error;
error = 0;
switch (name) {
case _PC_LINK_MAX:
*retval = LINK_MAX;
break;
case _PC_NAME_MAX:
*retval = NAME_MAX;
break;
case _PC_PATH_MAX:
*retval = PATH_MAX;
break;
case _PC_PIPE_BUF:
*retval = PIPE_BUF;
break;
case _PC_CHOWN_RESTRICTED:
*retval = 1;
break;
case _PC_NO_TRUNC:
*retval = 1;
break;
case _PC_SYNC_IO:
*retval = 1;
break;
case _PC_FILESIZEBITS:
*retval = 0; /* XXX Don't know which value should I return. */
break;
default:
error = EINVAL;
}
return error;
}
static int
tmpfs_vptofh(struct vop_vptofh_args *ap)
{
struct tmpfs_fid *tfhp;
struct tmpfs_node *node;
tfhp = (struct tmpfs_fid *)ap->a_fhp;
node = VP_TO_TMPFS_NODE(ap->a_vp);
tfhp->tf_len = sizeof(struct tmpfs_fid);
tfhp->tf_id = node->tn_id;
tfhp->tf_gen = node->tn_gen;
return (0);
}
static int
tmpfs_whiteout(struct vop_whiteout_args *ap)
{
struct vnode *dvp = ap->a_dvp;
struct componentname *cnp = ap->a_cnp;
struct tmpfs_dirent *de;
switch (ap->a_flags) {
case LOOKUP:
return (0);
case CREATE:
de = tmpfs_dir_lookup(VP_TO_TMPFS_DIR(dvp), NULL, cnp);
if (de != NULL)
return (de->td_node == NULL ? 0 : EEXIST);
return (tmpfs_dir_whiteout_add(dvp, cnp));
case DELETE:
tmpfs_dir_whiteout_remove(dvp, cnp);
return (0);
default:
panic("tmpfs_whiteout: unknown op");
}
}
/*
* vnode operations vector used for files stored in a tmpfs file system.
*/
struct vop_vector tmpfs_vnodeop_entries = {
.vop_default = &default_vnodeops,
.vop_lookup = vfs_cache_lookup,
.vop_cachedlookup = tmpfs_lookup,
.vop_create = tmpfs_create,
.vop_mknod = tmpfs_mknod,
.vop_open = tmpfs_open,
.vop_close = tmpfs_close,
.vop_access = tmpfs_access,
.vop_getattr = tmpfs_getattr,
.vop_setattr = tmpfs_setattr,
.vop_read = tmpfs_read,
.vop_write = tmpfs_write,
.vop_fsync = tmpfs_fsync,
.vop_remove = tmpfs_remove,
.vop_link = tmpfs_link,
.vop_rename = tmpfs_rename,
.vop_mkdir = tmpfs_mkdir,
.vop_rmdir = tmpfs_rmdir,
.vop_symlink = tmpfs_symlink,
.vop_readdir = tmpfs_readdir,
.vop_readlink = tmpfs_readlink,
.vop_inactive = tmpfs_inactive,
.vop_reclaim = tmpfs_reclaim,
.vop_print = tmpfs_print,
.vop_pathconf = tmpfs_pathconf,
.vop_vptofh = tmpfs_vptofh,
.vop_whiteout = tmpfs_whiteout,
.vop_bmap = VOP_EOPNOTSUPP,
};