zfs/module/zfs/zfs_dir.c

968 lines
25 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
#ifdef HAVE_ZPL
#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <sys/resource.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/mode.h>
#include <sys/kmem.h>
#include <sys/uio.h>
#include <sys/pathname.h>
#include <sys/cmn_err.h>
#include <sys/errno.h>
#include <sys/stat.h>
#include <sys/unistd.h>
#include <sys/sunddi.h>
#include <sys/random.h>
#include <sys/policy.h>
#include <sys/zfs_dir.h>
#include <sys/zfs_acl.h>
#include <sys/fs/zfs.h>
#include "fs/fs_subr.h"
#include <sys/zap.h>
#include <sys/dmu.h>
#include <sys/atomic.h>
#include <sys/zfs_ctldir.h>
#include <sys/zfs_fuid.h>
#include <sys/dnlc.h>
#include <sys/extdirent.h>
/*
* zfs_match_find() is used by zfs_dirent_lock() to peform zap lookups
* of names after deciding which is the appropriate lookup interface.
*/
static int
zfs_match_find(zfsvfs_t *zfsvfs, znode_t *dzp, char *name, boolean_t exact,
boolean_t update, int *deflags, pathname_t *rpnp, uint64_t *zoid)
{
int error;
if (zfsvfs->z_norm) {
matchtype_t mt = MT_FIRST;
boolean_t conflict = B_FALSE;
size_t bufsz = 0;
char *buf = NULL;
if (rpnp) {
buf = rpnp->pn_buf;
bufsz = rpnp->pn_bufsize;
}
if (exact)
mt = MT_EXACT;
/*
* In the non-mixed case we only expect there would ever
* be one match, but we need to use the normalizing lookup.
*/
error = zap_lookup_norm(zfsvfs->z_os, dzp->z_id, name, 8, 1,
zoid, mt, buf, bufsz, &conflict);
if (!error && deflags)
*deflags = conflict ? ED_CASE_CONFLICT : 0;
} else {
error = zap_lookup(zfsvfs->z_os, dzp->z_id, name, 8, 1, zoid);
}
*zoid = ZFS_DIRENT_OBJ(*zoid);
if (error == ENOENT && update)
dnlc_update(ZTOV(dzp), name, DNLC_NO_VNODE);
return (error);
}
/*
* Lock a directory entry. A dirlock on <dzp, name> protects that name
* in dzp's directory zap object. As long as you hold a dirlock, you can
* assume two things: (1) dzp cannot be reaped, and (2) no other thread
* can change the zap entry for (i.e. link or unlink) this name.
*
* Input arguments:
* dzp - znode for directory
* name - name of entry to lock
* flag - ZNEW: if the entry already exists, fail with EEXIST.
* ZEXISTS: if the entry does not exist, fail with ENOENT.
* ZSHARED: allow concurrent access with other ZSHARED callers.
* ZXATTR: we want dzp's xattr directory
* ZCILOOK: On a mixed sensitivity file system,
* this lookup should be case-insensitive.
* ZCIEXACT: On a purely case-insensitive file system,
* this lookup should be case-sensitive.
* ZRENAMING: we are locking for renaming, force narrow locks
*
* Output arguments:
* zpp - pointer to the znode for the entry (NULL if there isn't one)
* dlpp - pointer to the dirlock for this entry (NULL on error)
* direntflags - (case-insensitive lookup only)
* flags if multiple case-sensitive matches exist in directory
* realpnp - (case-insensitive lookup only)
* actual name matched within the directory
*
* Return value: 0 on success or errno on failure.
*
* NOTE: Always checks for, and rejects, '.' and '..'.
* NOTE: For case-insensitive file systems we take wide locks (see below),
* but return znode pointers to a single match.
*/
int
zfs_dirent_lock(zfs_dirlock_t **dlpp, znode_t *dzp, char *name, znode_t **zpp,
int flag, int *direntflags, pathname_t *realpnp)
{
zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
zfs_dirlock_t *dl;
boolean_t update;
boolean_t exact;
uint64_t zoid;
vnode_t *vp = NULL;
int error = 0;
int cmpflags;
*zpp = NULL;
*dlpp = NULL;
/*
* Verify that we are not trying to lock '.', '..', or '.zfs'
*/
if (name[0] == '.' &&
(name[1] == '\0' || (name[1] == '.' && name[2] == '\0')) ||
zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0)
return (EEXIST);
/*
* Case sensitivity and normalization preferences are set when
* the file system is created. These are stored in the
* zfsvfs->z_case and zfsvfs->z_norm fields. These choices
* affect what vnodes can be cached in the DNLC, how we
* perform zap lookups, and the "width" of our dirlocks.
*
* A normal dirlock locks a single name. Note that with
* normalization a name can be composed multiple ways, but
* when normalized, these names all compare equal. A wide
* dirlock locks multiple names. We need these when the file
* system is supporting mixed-mode access. It is sometimes
* necessary to lock all case permutations of file name at
* once so that simultaneous case-insensitive/case-sensitive
* behaves as rationally as possible.
*/
/*
* Decide if exact matches should be requested when performing
* a zap lookup on file systems supporting case-insensitive
* access.
*/
exact =
((zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && (flag & ZCIEXACT)) ||
((zfsvfs->z_case == ZFS_CASE_MIXED) && !(flag & ZCILOOK));
/*
* Only look in or update the DNLC if we are looking for the
* name on a file system that does not require normalization
* or case folding. We can also look there if we happen to be
* on a non-normalizing, mixed sensitivity file system IF we
* are looking for the exact name.
*
* Maybe can add TO-UPPERed version of name to dnlc in ci-only
* case for performance improvement?
*/
update = !zfsvfs->z_norm ||
((zfsvfs->z_case == ZFS_CASE_MIXED) &&
!(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER) && !(flag & ZCILOOK));
/*
* ZRENAMING indicates we are in a situation where we should
* take narrow locks regardless of the file system's
* preferences for normalizing and case folding. This will
* prevent us deadlocking trying to grab the same wide lock
* twice if the two names happen to be case-insensitive
* matches.
*/
if (flag & ZRENAMING)
cmpflags = 0;
else
cmpflags = zfsvfs->z_norm;
/*
* Wait until there are no locks on this name.
*/
rw_enter(&dzp->z_name_lock, RW_READER);
mutex_enter(&dzp->z_lock);
for (;;) {
if (dzp->z_unlinked) {
mutex_exit(&dzp->z_lock);
rw_exit(&dzp->z_name_lock);
return (ENOENT);
}
for (dl = dzp->z_dirlocks; dl != NULL; dl = dl->dl_next) {
if ((u8_strcmp(name, dl->dl_name, 0, cmpflags,
U8_UNICODE_LATEST, &error) == 0) || error != 0)
break;
}
if (error != 0) {
mutex_exit(&dzp->z_lock);
rw_exit(&dzp->z_name_lock);
return (ENOENT);
}
if (dl == NULL) {
/*
* Allocate a new dirlock and add it to the list.
*/
dl = kmem_alloc(sizeof (zfs_dirlock_t), KM_SLEEP);
cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL);
dl->dl_name = name;
dl->dl_sharecnt = 0;
dl->dl_namesize = 0;
dl->dl_dzp = dzp;
dl->dl_next = dzp->z_dirlocks;
dzp->z_dirlocks = dl;
break;
}
if ((flag & ZSHARED) && dl->dl_sharecnt != 0)
break;
cv_wait(&dl->dl_cv, &dzp->z_lock);
}
if ((flag & ZSHARED) && ++dl->dl_sharecnt > 1 && dl->dl_namesize == 0) {
/*
* We're the second shared reference to dl. Make a copy of
* dl_name in case the first thread goes away before we do.
* Note that we initialize the new name before storing its
* pointer into dl_name, because the first thread may load
* dl->dl_name at any time. He'll either see the old value,
* which is his, or the new shared copy; either is OK.
*/
dl->dl_namesize = strlen(dl->dl_name) + 1;
name = kmem_alloc(dl->dl_namesize, KM_SLEEP);
bcopy(dl->dl_name, name, dl->dl_namesize);
dl->dl_name = name;
}
mutex_exit(&dzp->z_lock);
/*
* We have a dirlock on the name. (Note that it is the dirlock,
* not the dzp's z_lock, that protects the name in the zap object.)
* See if there's an object by this name; if so, put a hold on it.
*/
if (flag & ZXATTR) {
zoid = dzp->z_phys->zp_xattr;
error = (zoid == 0 ? ENOENT : 0);
} else {
if (update)
vp = dnlc_lookup(ZTOV(dzp), name);
if (vp == DNLC_NO_VNODE) {
VN_RELE(vp);
error = ENOENT;
} else if (vp) {
if (flag & ZNEW) {
zfs_dirent_unlock(dl);
VN_RELE(vp);
return (EEXIST);
}
*dlpp = dl;
*zpp = VTOZ(vp);
return (0);
} else {
error = zfs_match_find(zfsvfs, dzp, name, exact,
update, direntflags, realpnp, &zoid);
}
}
if (error) {
if (error != ENOENT || (flag & ZEXISTS)) {
zfs_dirent_unlock(dl);
return (error);
}
} else {
if (flag & ZNEW) {
zfs_dirent_unlock(dl);
return (EEXIST);
}
error = zfs_zget(zfsvfs, zoid, zpp);
if (error) {
zfs_dirent_unlock(dl);
return (error);
}
if (!(flag & ZXATTR) && update)
dnlc_update(ZTOV(dzp), name, ZTOV(*zpp));
}
*dlpp = dl;
return (0);
}
/*
* Unlock this directory entry and wake anyone who was waiting for it.
*/
void
zfs_dirent_unlock(zfs_dirlock_t *dl)
{
znode_t *dzp = dl->dl_dzp;
zfs_dirlock_t **prev_dl, *cur_dl;
mutex_enter(&dzp->z_lock);
rw_exit(&dzp->z_name_lock);
if (dl->dl_sharecnt > 1) {
dl->dl_sharecnt--;
mutex_exit(&dzp->z_lock);
return;
}
prev_dl = &dzp->z_dirlocks;
while ((cur_dl = *prev_dl) != dl)
prev_dl = &cur_dl->dl_next;
*prev_dl = dl->dl_next;
cv_broadcast(&dl->dl_cv);
mutex_exit(&dzp->z_lock);
if (dl->dl_namesize != 0)
kmem_free(dl->dl_name, dl->dl_namesize);
cv_destroy(&dl->dl_cv);
kmem_free(dl, sizeof (*dl));
}
/*
* Look up an entry in a directory.
*
* NOTE: '.' and '..' are handled as special cases because
* no directory entries are actually stored for them. If this is
* the root of a filesystem, then '.zfs' is also treated as a
* special pseudo-directory.
*/
int
zfs_dirlook(znode_t *dzp, char *name, vnode_t **vpp, int flags,
int *deflg, pathname_t *rpnp)
{
zfs_dirlock_t *dl;
znode_t *zp;
int error = 0;
if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) {
*vpp = ZTOV(dzp);
VN_HOLD(*vpp);
} else if (name[0] == '.' && name[1] == '.' && name[2] == 0) {
zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
/*
* If we are a snapshot mounted under .zfs, return
* the vp for the snapshot directory.
*/
if (dzp->z_phys->zp_parent == dzp->z_id &&
zfsvfs->z_parent != zfsvfs) {
error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir,
"snapshot", vpp, NULL, 0, NULL, kcred,
NULL, NULL, NULL);
return (error);
}
rw_enter(&dzp->z_parent_lock, RW_READER);
error = zfs_zget(zfsvfs, dzp->z_phys->zp_parent, &zp);
if (error == 0)
*vpp = ZTOV(zp);
rw_exit(&dzp->z_parent_lock);
} else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) {
*vpp = zfsctl_root(dzp);
} else {
int zf;
zf = ZEXISTS | ZSHARED;
if (flags & FIGNORECASE)
zf |= ZCILOOK;
error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp);
if (error == 0) {
*vpp = ZTOV(zp);
zfs_dirent_unlock(dl);
dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */
}
rpnp = NULL;
}
if ((flags & FIGNORECASE) && rpnp && !error)
(void) strlcpy(rpnp->pn_buf, name, rpnp->pn_bufsize);
return (error);
}
/*
* unlinked Set (formerly known as the "delete queue") Error Handling
*
* When dealing with the unlinked set, we dmu_tx_hold_zap(), but we
* don't specify the name of the entry that we will be manipulating. We
* also fib and say that we won't be adding any new entries to the
* unlinked set, even though we might (this is to lower the minimum file
* size that can be deleted in a full filesystem). So on the small
* chance that the nlink list is using a fat zap (ie. has more than
* 2000 entries), we *may* not pre-read a block that's needed.
* Therefore it is remotely possible for some of the assertions
* regarding the unlinked set below to fail due to i/o error. On a
* nondebug system, this will result in the space being leaked.
*/
void
zfs_unlinked_add(znode_t *zp, dmu_tx_t *tx)
{
zfsvfs_t *zfsvfs = zp->z_zfsvfs;
ASSERT(zp->z_unlinked);
ASSERT3U(zp->z_phys->zp_links, ==, 0);
VERIFY3U(0, ==,
zap_add_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
}
/*
* Clean up any znodes that had no links when we either crashed or
* (force) umounted the file system.
*/
void
zfs_unlinked_drain(zfsvfs_t *zfsvfs)
{
zap_cursor_t zc;
zap_attribute_t zap;
dmu_object_info_t doi;
znode_t *zp;
int error;
/*
* Interate over the contents of the unlinked set.
*/
for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj);
zap_cursor_retrieve(&zc, &zap) == 0;
zap_cursor_advance(&zc)) {
/*
* See what kind of object we have in list
*/
error = dmu_object_info(zfsvfs->z_os,
zap.za_first_integer, &doi);
if (error != 0)
continue;
ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) ||
(doi.doi_type == DMU_OT_DIRECTORY_CONTENTS));
/*
* We need to re-mark these list entries for deletion,
* so we pull them back into core and set zp->z_unlinked.
*/
error = zfs_zget(zfsvfs, zap.za_first_integer, &zp);
/*
* We may pick up znodes that are already marked for deletion.
* This could happen during the purge of an extended attribute
* directory. All we need to do is skip over them, since they
* are already in the system marked z_unlinked.
*/
if (error != 0)
continue;
zp->z_unlinked = B_TRUE;
VN_RELE(ZTOV(zp));
}
zap_cursor_fini(&zc);
}
/*
* Delete the entire contents of a directory. Return a count
* of the number of entries that could not be deleted. If we encounter
* an error, return a count of at least one so that the directory stays
* in the unlinked set.
*
* NOTE: this function assumes that the directory is inactive,
* so there is no need to lock its entries before deletion.
* Also, it assumes the directory contents is *only* regular
* files.
*/
static int
zfs_purgedir(znode_t *dzp)
{
zap_cursor_t zc;
zap_attribute_t zap;
znode_t *xzp;
dmu_tx_t *tx;
zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
zfs_dirlock_t dl;
int skipped = 0;
int error;
for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
(error = zap_cursor_retrieve(&zc, &zap)) == 0;
zap_cursor_advance(&zc)) {
error = zfs_zget(zfsvfs,
ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
if (error) {
skipped += 1;
continue;
}
ASSERT((ZTOV(xzp)->v_type == VREG) ||
(ZTOV(xzp)->v_type == VLNK));
tx = dmu_tx_create(zfsvfs->z_os);
dmu_tx_hold_bonus(tx, dzp->z_id);
dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
dmu_tx_hold_bonus(tx, xzp->z_id);
dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
VN_RELE(ZTOV(xzp));
skipped += 1;
continue;
}
bzero(&dl, sizeof (dl));
dl.dl_dzp = dzp;
dl.dl_name = zap.za_name;
error = zfs_link_destroy(&dl, xzp, tx, 0, NULL);
if (error)
skipped += 1;
dmu_tx_commit(tx);
VN_RELE(ZTOV(xzp));
}
zap_cursor_fini(&zc);
if (error != ENOENT)
skipped += 1;
return (skipped);
}
void
zfs_rmnode(znode_t *zp)
{
zfsvfs_t *zfsvfs = zp->z_zfsvfs;
objset_t *os = zfsvfs->z_os;
znode_t *xzp = NULL;
dmu_tx_t *tx;
uint64_t acl_obj;
int error;
ASSERT(ZTOV(zp)->v_count == 0);
ASSERT(zp->z_phys->zp_links == 0);
/*
* If this is an attribute directory, purge its contents.
*/
if (ZTOV(zp)->v_type == VDIR && (zp->z_phys->zp_flags & ZFS_XATTR)) {
if (zfs_purgedir(zp) != 0) {
/*
* Not enough space to delete some xattrs.
* Leave it in the unlinked set.
*/
zfs_znode_dmu_fini(zp);
zfs_znode_free(zp);
return;
}
}
/*
* Free up all the data in the file.
*/
error = dmu_free_long_range(os, zp->z_id, 0, DMU_OBJECT_END);
if (error) {
/*
* Not enough space. Leave the file in the unlinked set.
*/
zfs_znode_dmu_fini(zp);
zfs_znode_free(zp);
return;
}
/*
* If the file has extended attributes, we're going to unlink
* the xattr dir.
*/
if (zp->z_phys->zp_xattr) {
error = zfs_zget(zfsvfs, zp->z_phys->zp_xattr, &xzp);
ASSERT(error == 0);
}
acl_obj = zp->z_phys->zp_acl.z_acl_extern_obj;
/*
* Set up the final transaction.
*/
tx = dmu_tx_create(os);
dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END);
dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
if (xzp) {
dmu_tx_hold_bonus(tx, xzp->z_id);
dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL);
}
if (acl_obj)
dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
/*
* Not enough space to delete the file. Leave it in the
* unlinked set, leaking it until the fs is remounted (at
* which point we'll call zfs_unlinked_drain() to process it).
*/
dmu_tx_abort(tx);
zfs_znode_dmu_fini(zp);
zfs_znode_free(zp);
goto out;
}
if (xzp) {
dmu_buf_will_dirty(xzp->z_dbuf, tx);
mutex_enter(&xzp->z_lock);
xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */
xzp->z_phys->zp_links = 0; /* no more links to it */
mutex_exit(&xzp->z_lock);
zfs_unlinked_add(xzp, tx);
}
/* Remove this znode from the unlinked set */
VERIFY3U(0, ==,
zap_remove_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx));
zfs_znode_delete(zp, tx);
dmu_tx_commit(tx);
out:
if (xzp)
VN_RELE(ZTOV(xzp));
}
static uint64_t
zfs_dirent(znode_t *zp)
{
uint64_t de = zp->z_id;
if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE)
de |= IFTODT((zp)->z_phys->zp_mode) << 60;
return (de);
}
/*
* Link zp into dl. Can only fail if zp has been unlinked.
*/
int
zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag)
{
znode_t *dzp = dl->dl_dzp;
vnode_t *vp = ZTOV(zp);
uint64_t value;
int zp_is_dir = (vp->v_type == VDIR);
int error;
dmu_buf_will_dirty(zp->z_dbuf, tx);
mutex_enter(&zp->z_lock);
if (!(flag & ZRENAMING)) {
if (zp->z_unlinked) { /* no new links to unlinked zp */
ASSERT(!(flag & (ZNEW | ZEXISTS)));
mutex_exit(&zp->z_lock);
return (ENOENT);
}
zp->z_phys->zp_links++;
}
zp->z_phys->zp_parent = dzp->z_id; /* dzp is now zp's parent */
if (!(flag & ZNEW))
zfs_time_stamper_locked(zp, STATE_CHANGED, tx);
mutex_exit(&zp->z_lock);
dmu_buf_will_dirty(dzp->z_dbuf, tx);
mutex_enter(&dzp->z_lock);
dzp->z_phys->zp_size++; /* one dirent added */
dzp->z_phys->zp_links += zp_is_dir; /* ".." link from zp */
zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx);
mutex_exit(&dzp->z_lock);
value = zfs_dirent(zp);
error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name,
8, 1, &value, tx);
ASSERT(error == 0);
dnlc_update(ZTOV(dzp), dl->dl_name, vp);
return (0);
}
/*
* Unlink zp from dl, and mark zp for deletion if this was the last link.
* Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST).
* If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list.
* If it's non-NULL, we use it to indicate whether the znode needs deletion,
* and it's the caller's job to do it.
*/
int
zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag,
boolean_t *unlinkedp)
{
znode_t *dzp = dl->dl_dzp;
vnode_t *vp = ZTOV(zp);
int zp_is_dir = (vp->v_type == VDIR);
boolean_t unlinked = B_FALSE;
int error;
dnlc_remove(ZTOV(dzp), dl->dl_name);
if (!(flag & ZRENAMING)) {
dmu_buf_will_dirty(zp->z_dbuf, tx);
if (vn_vfswlock(vp)) /* prevent new mounts on zp */
return (EBUSY);
if (vn_ismntpt(vp)) { /* don't remove mount point */
vn_vfsunlock(vp);
return (EBUSY);
}
mutex_enter(&zp->z_lock);
if (zp_is_dir && !zfs_dirempty(zp)) { /* dir not empty */
mutex_exit(&zp->z_lock);
vn_vfsunlock(vp);
return (EEXIST);
}
if (zp->z_phys->zp_links <= zp_is_dir) {
zfs_panic_recover("zfs: link count on %s is %u, "
"should be at least %u",
zp->z_vnode->v_path ? zp->z_vnode->v_path :
"<unknown>", (int)zp->z_phys->zp_links,
zp_is_dir + 1);
zp->z_phys->zp_links = zp_is_dir + 1;
}
if (--zp->z_phys->zp_links == zp_is_dir) {
zp->z_unlinked = B_TRUE;
zp->z_phys->zp_links = 0;
unlinked = B_TRUE;
} else {
zfs_time_stamper_locked(zp, STATE_CHANGED, tx);
}
mutex_exit(&zp->z_lock);
vn_vfsunlock(vp);
}
dmu_buf_will_dirty(dzp->z_dbuf, tx);
mutex_enter(&dzp->z_lock);
dzp->z_phys->zp_size--; /* one dirent removed */
dzp->z_phys->zp_links -= zp_is_dir; /* ".." link from zp */
zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx);
mutex_exit(&dzp->z_lock);
if (zp->z_zfsvfs->z_norm) {
if (((zp->z_zfsvfs->z_case == ZFS_CASE_INSENSITIVE) &&
(flag & ZCIEXACT)) ||
((zp->z_zfsvfs->z_case == ZFS_CASE_MIXED) &&
!(flag & ZCILOOK)))
error = zap_remove_norm(zp->z_zfsvfs->z_os,
dzp->z_id, dl->dl_name, MT_EXACT, tx);
else
error = zap_remove_norm(zp->z_zfsvfs->z_os,
dzp->z_id, dl->dl_name, MT_FIRST, tx);
} else {
error = zap_remove(zp->z_zfsvfs->z_os,
dzp->z_id, dl->dl_name, tx);
}
ASSERT(error == 0);
if (unlinkedp != NULL)
*unlinkedp = unlinked;
else if (unlinked)
zfs_unlinked_add(zp, tx);
return (0);
}
/*
* Indicate whether the directory is empty. Works with or without z_lock
* held, but can only be consider a hint in the latter case. Returns true
* if only "." and ".." remain and there's no work in progress.
*/
boolean_t
zfs_dirempty(znode_t *dzp)
{
return (dzp->z_phys->zp_size == 2 && dzp->z_dirlocks == 0);
}
int
zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr)
{
zfsvfs_t *zfsvfs = zp->z_zfsvfs;
znode_t *xzp;
dmu_tx_t *tx;
int error;
zfs_acl_ids_t acl_ids;
boolean_t fuid_dirtied;
*xvpp = NULL;
if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr))
return (error);
if ((error = zfs_acl_ids_create(zp, IS_XATTR, vap, cr, NULL,
&acl_ids)) != 0)
return (error);
if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
zfs_acl_ids_free(&acl_ids);
return (EDQUOT);
}
tx = dmu_tx_create(zfsvfs->z_os);
dmu_tx_hold_bonus(tx, zp->z_id);
dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
fuid_dirtied = zfsvfs->z_fuid_dirty;
if (fuid_dirtied)
zfs_fuid_txhold(zfsvfs, tx);
error = dmu_tx_assign(tx, TXG_NOWAIT);
if (error) {
zfs_acl_ids_free(&acl_ids);
if (error == ERESTART)
dmu_tx_wait(tx);
dmu_tx_abort(tx);
return (error);
}
zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, 0, &acl_ids);
if (fuid_dirtied)
zfs_fuid_sync(zfsvfs, tx);
ASSERT(xzp->z_phys->zp_parent == zp->z_id);
dmu_buf_will_dirty(zp->z_dbuf, tx);
zp->z_phys->zp_xattr = xzp->z_id;
(void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp,
xzp, "", NULL, acl_ids.z_fuidp, vap);
zfs_acl_ids_free(&acl_ids);
dmu_tx_commit(tx);
*xvpp = ZTOV(xzp);
return (0);
}
/*
* Return a znode for the extended attribute directory for zp.
* ** If the directory does not already exist, it is created **
*
* IN: zp - znode to obtain attribute directory from
* cr - credentials of caller
* flags - flags from the VOP_LOOKUP call
*
* OUT: xzpp - pointer to extended attribute znode
*
* RETURN: 0 on success
* error number on failure
*/
int
zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags)
{
zfsvfs_t *zfsvfs = zp->z_zfsvfs;
znode_t *xzp;
zfs_dirlock_t *dl;
vattr_t va;
int error;
top:
error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL);
if (error)
return (error);
if (xzp != NULL) {
*xvpp = ZTOV(xzp);
zfs_dirent_unlock(dl);
return (0);
}
ASSERT(zp->z_phys->zp_xattr == 0);
if (!(flags & CREATE_XATTR_DIR)) {
zfs_dirent_unlock(dl);
return (ENOENT);
}
if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) {
zfs_dirent_unlock(dl);
return (EROFS);
}
/*
* The ability to 'create' files in an attribute
* directory comes from the write_xattr permission on the base file.
*
* The ability to 'search' an attribute directory requires
* read_xattr permission on the base file.
*
* Once in a directory the ability to read/write attributes
* is controlled by the permissions on the attribute file.
*/
va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID;
va.va_type = VDIR;
va.va_mode = S_IFDIR | S_ISVTX | 0777;
zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid);
error = zfs_make_xattrdir(zp, &va, xvpp, cr);
zfs_dirent_unlock(dl);
if (error == ERESTART) {
/* NB: we already did dmu_tx_wait() if necessary */
goto top;
}
return (error);
}
/*
* Decide whether it is okay to remove within a sticky directory.
*
* In sticky directories, write access is not sufficient;
* you can remove entries from a directory only if:
*
* you own the directory,
* you own the entry,
* the entry is a plain file and you have write access,
* or you are privileged (checked in secpolicy...).
*
* The function returns 0 if remove access is granted.
*/
int
zfs_sticky_remove_access(znode_t *zdp, znode_t *zp, cred_t *cr)
{
uid_t uid;
uid_t downer;
uid_t fowner;
zfsvfs_t *zfsvfs = zdp->z_zfsvfs;
if (zdp->z_zfsvfs->z_replay)
return (0);
if ((zdp->z_phys->zp_mode & S_ISVTX) == 0)
return (0);
downer = zfs_fuid_map_id(zfsvfs, zdp->z_phys->zp_uid, cr, ZFS_OWNER);
fowner = zfs_fuid_map_id(zfsvfs, zp->z_phys->zp_uid, cr, ZFS_OWNER);
if ((uid = crgetuid(cr)) == downer || uid == fowner ||
(ZTOV(zp)->v_type == VREG &&
zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0))
return (0);
else
return (secpolicy_vnode_remove(cr));
}
#endif /* HAVE_ZPL */