d/freebsd-nq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity
81e97e2187
freebsd-nq/module/zfs/zfs_dir.c
Brian Behlendorf 3558fd73b5 Prototype/structure update for Linux 
I appologize in advance why to many things ended up in this commit.
When it could be seperated in to a whole series of commits teasing
that all apart now would take considerable time and I'm not sure
there's much merrit in it.  As such I'll just summerize the intent
of the changes which are all (or partly) in this commit.  Broadly
the intent is to remove as much Solaris specific code as possible
and replace it with native Linux equivilants.  More specifically:

1) Replace all instances of zfsvfs_t with zfs_sb_t.  While the
type is largely the same calling it private super block data
rather than a zfsvfs is more consistent with how Linux names
this.  While non critical it makes the code easier to read when
your thinking in Linux friendly VFS terms.

2) Replace vnode_t with struct inode.  The Linux VFS doesn't have
the notion of a vnode and there's absolutely no good reason to
create one.  There are in fact several good reasons to remove it.
It just adds overhead on Linux if we were to manage one, it
conplicates the code, and it likely will lead to bugs so there's
a good change it will be out of date.  The code has been updated
to remove all need for this type.

3) Replace all vtype_t's with umode types.  Along with this shift
all uses of types to mode bits.  The Solaris code would pass a
vtype which is redundant with the Linux mode.  Just update all the
code to use the Linux mode macros and remove this redundancy.

4) Remove using of vn_* helpers and replace where needed with
inode helpers.  The big example here is creating iput_aync to
replace vn_rele_async.  Other vn helpers will be addressed as
needed but they should be be emulated.  They are a Solaris VFS'ism
and should simply be replaced with Linux equivilants.

5) Update znode alloc/free code.  Under Linux it's common to
embed the inode specific data with the inode itself.  This removes
the need for an extra memory allocation.  In zfs this information
is called a znode and it now embeds the inode with it.  Allocators
have been updated accordingly.

6) Minimal integration with the vfs flags for setting up the
super block and handling mount options has been added this
code will need to be refined but functionally it's all there.

This will be the first and last of these to large to review commits.
2011-02-10 09:27:21 -08:00

1093 lines
29 KiB
C
Raw Blame History

/*
* 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
*/
#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_fuid.h>
#include <sys/sa.h>
#include <sys/zfs_sa.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(zfs_sb_t *zsb, znode_t *dzp, char *name, boolean_t exact,
boolean_t update, int *deflags, pathname_t *rpnp, uint64_t *zoid)
{
int error;
if (zsb->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(zsb->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(zsb->z_os, dzp->z_id, name, 8, 1, zoid);
}
*zoid = ZFS_DIRENT_OBJ(*zoid);
#ifdef HAVE_DNLC
if (error == ENOENT && update)
dnlc_update(ZTOI(dzp), name, DNLC_NO_VNODE);
#endif /* HAVE_DNLC */
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
* ZHAVELOCK: Don't grab the z_name_lock for this call. The
* current thread already holds it.
*
* 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)
{
zfs_sb_t *zsb = ZTOZSB(dzp);
zfs_dirlock_t *dl;
boolean_t update;
boolean_t exact;
uint64_t zoid;
#ifdef HAVE_DNLC
vnode_t *vp = NULL;
#endif /* HAVE_DNLC */
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
* zsb->z_case and zsb->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 =
((zsb->z_case == ZFS_CASE_INSENSITIVE) && (flag & ZCIEXACT)) ||
((zsb->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 = !zsb->z_norm ||
((zsb->z_case == ZFS_CASE_MIXED) &&
!(zsb->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 = zsb->z_norm;
/*
* Wait until there are no locks on this name.
*
* Don't grab the the lock if it is already held. However, cannot
* have both ZSHARED and ZHAVELOCK together.
*/
ASSERT(!(flag & ZSHARED) || !(flag & ZHAVELOCK));
if (!(flag & ZHAVELOCK))
rw_enter(&dzp->z_name_lock, RW_READER);
mutex_enter(&dzp->z_lock);
for (;;) {
if (dzp->z_unlinked) {
mutex_exit(&dzp->z_lock);
if (!(flag & ZHAVELOCK))
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);
if (!(flag & ZHAVELOCK))
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_namelock = 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 the z_name_lock was NOT held for this dirlock record it.
*/
if (flag & ZHAVELOCK)
dl->dl_namelock = 1;
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) {
error = sa_lookup(dzp->z_sa_hdl, SA_ZPL_XATTR(zsb), &zoid,
sizeof (zoid));
if (error == 0)
error = (zoid == 0 ? ENOENT : 0);
} else {
#ifdef HAVE_DNLC
if (update)
vp = dnlc_lookup(ZTOI(dzp), name);
if (vp == DNLC_NO_VNODE) {
iput(vp);
error = ENOENT;
} else if (vp) {
if (flag & ZNEW) {
zfs_dirent_unlock(dl);
iput(vp);
return (EEXIST);
}
*dlpp = dl;
*zpp = VTOZ(vp);
return (0);
} else {
error = zfs_match_find(zsb, dzp, name, exact,
update, direntflags, realpnp, &zoid);
}
#else
error = zfs_match_find(zsb, dzp, name, exact,
update, direntflags, realpnp, &zoid);
#endif /* HAVE_DNLC */
}
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(zsb, zoid, zpp);
if (error) {
zfs_dirent_unlock(dl);
return (error);
}
#ifdef HAVE_DNLC
if (!(flag & ZXATTR) && update)
dnlc_update(ZTOI(dzp), name, ZTOI(*zpp));
#endif /* HAVE_DNLC */
}
*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);
if (!dl->dl_namelock)
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, struct inode **ipp, int flags,
int *deflg, pathname_t *rpnp)
{
zfs_dirlock_t *dl;
znode_t *zp;
int error = 0;
uint64_t parent;
if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) {
*ipp = ZTOI(dzp);
igrab(*ipp);
} else if (name[0] == '.' && name[1] == '.' && name[2] == 0) {
zfs_sb_t *zsb = ZTOZSB(dzp);
/*
* If we are a snapshot mounted under .zfs, return
* the vp for the snapshot directory.
*/
if ((error = sa_lookup(dzp->z_sa_hdl,
SA_ZPL_PARENT(zsb), &parent, sizeof (parent))) != 0)
return (error);
#ifdef HAVE_SNAPSHOT
if (parent == dzp->z_id && zsb->z_parent != zsb) {
error = zfsctl_root_lookup(zsb->z_parent->z_ctldir,
"snapshot", ipp, NULL, 0, NULL, kcred,
NULL, NULL, NULL);
return (error);
}
#endif /* HAVE_SNAPSHOT */
rw_enter(&dzp->z_parent_lock, RW_READER);
error = zfs_zget(zsb, parent, &zp);
if (error == 0)
*ipp = ZTOI(zp);
rw_exit(&dzp->z_parent_lock);
#ifdef HAVE_SNAPSHOT
} else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) {
*ipp = zfsctl_root(dzp);
#endif /* HAVE_SNAPSHOT */
} 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) {
*ipp = ZTOI(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)
{
zfs_sb_t *zsb = ZTOZSB(zp);
ASSERT(zp->z_unlinked);
ASSERT(zp->z_links == 0);
VERIFY3U(0, ==,
zap_add_int(zsb->z_os, zsb->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(zfs_sb_t *zsb)
{
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, zsb->z_os, zsb->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(zsb->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(zsb, 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;
iput(ZTOI(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;
zfs_sb_t *zsb = ZTOZSB(dzp);
zfs_dirlock_t dl;
int skipped = 0;
int error;
for (zap_cursor_init(&zc, zsb->z_os, dzp->z_id);
(error = zap_cursor_retrieve(&zc, &zap)) == 0;
zap_cursor_advance(&zc)) {
error = zfs_zget(zsb,
ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
if (error) {
skipped += 1;
continue;
}
ASSERT(S_ISREG(ZTOI(xzp)->i_mode)||S_ISLNK(ZTOI(xzp)->i_mode));
tx = dmu_tx_create(zsb->z_os);
dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
dmu_tx_hold_zap(tx, zsb->z_unlinkedobj, FALSE, NULL);
/* Is this really needed ? */
zfs_sa_upgrade_txholds(tx, xzp);
error = dmu_tx_assign(tx, TXG_WAIT);
if (error) {
dmu_tx_abort(tx);
iput(ZTOI(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);
iput(ZTOI(xzp));
}
zap_cursor_fini(&zc);
if (error != ENOENT)
skipped += 1;
return (skipped);
}
void
zfs_rmnode(znode_t *zp)
{
zfs_sb_t *zsb = ZTOZSB(zp);
objset_t *os = zsb->z_os;
znode_t *xzp = NULL;
dmu_tx_t *tx;
uint64_t acl_obj;
uint64_t xattr_obj;
int error;
ASSERT(zp->z_links == 0);
ASSERT(atomic_read(&ZTOI(zp)->i_count) == 0);
/*
* If this is an attribute directory, purge its contents.
*/
if (S_ISDIR(ZTOI(zp)->i_mode) && (zp->z_pflags & 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_inode_destroy(ZTOI(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_inode_destroy(ZTOI(zp));
return;
}
/*
* If the file has extended attributes, we're going to unlink
* the xattr dir.
*/
error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zsb),
&xattr_obj, sizeof (xattr_obj));
if (error == 0 && xattr_obj) {
error = zfs_zget(zsb, xattr_obj, &xzp);
ASSERT(error == 0);
}
acl_obj = zfs_external_acl(zp);
/*
* 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, zsb->z_unlinkedobj, FALSE, NULL);
if (xzp) {
dmu_tx_hold_zap(tx, zsb->z_unlinkedobj, TRUE, NULL);
dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
}
if (acl_obj)
dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END);
zfs_sa_upgrade_txholds(tx, zp);
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_inode_destroy(ZTOI(zp));
goto out;
}
if (xzp) {
ASSERT(error == 0);
mutex_enter(&xzp->z_lock);
xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */
xzp->z_links = 0; /* no more links to it */
VERIFY(0 == sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zsb),
&xzp->z_links, sizeof (xzp->z_links), tx));
mutex_exit(&xzp->z_lock);
zfs_unlinked_add(xzp, tx);
}
/* Remove this znode from the unlinked set */
VERIFY3U(0, ==,
zap_remove_int(zsb->z_os, zsb->z_unlinkedobj, zp->z_id, tx));
zfs_znode_delete(zp, tx);
dmu_tx_commit(tx);
out:
if (xzp)
iput(ZTOI(xzp));
}
static uint64_t
zfs_dirent(znode_t *zp, uint64_t mode)
{
uint64_t de = zp->z_id;
if (ZTOZSB(zp)->z_version >= ZPL_VERSION_DIRENT_TYPE)
de |= IFTODT(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;
zfs_sb_t *zsb = ZTOZSB(zp);
uint64_t value;
int zp_is_dir = S_ISDIR(ZTOI(zp)->i_mode);
sa_bulk_attr_t bulk[5];
uint64_t mtime[2], ctime[2];
int count = 0;
int error;
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_links++;
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zsb), NULL,
&zp->z_links, sizeof (zp->z_links));
}
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zsb), NULL,
&dzp->z_id, sizeof (dzp->z_id));
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zsb), NULL,
&zp->z_pflags, sizeof (zp->z_pflags));
if (!(flag & ZNEW)) {
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zsb), NULL,
ctime, sizeof (ctime));
zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime,
ctime, B_TRUE);
}
error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
ASSERT(error == 0);
mutex_exit(&zp->z_lock);
mutex_enter(&dzp->z_lock);
dzp->z_size++;
dzp->z_links += zp_is_dir;
count = 0;
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zsb), NULL,
&dzp->z_size, sizeof (dzp->z_size));
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zsb), NULL,
&dzp->z_links, sizeof (dzp->z_links));
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zsb), NULL,
mtime, sizeof (mtime));
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zsb), NULL,
ctime, sizeof (ctime));
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zsb), NULL,
&dzp->z_pflags, sizeof (dzp->z_pflags));
zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
ASSERT(error == 0);
mutex_exit(&dzp->z_lock);
value = zfs_dirent(zp, zp->z_mode);
error = zap_add(ZTOZSB(zp)->z_os, dzp->z_id, dl->dl_name,
8, 1, &value, tx);
ASSERT(error == 0);
#ifdef HAVE_DNLC
dnlc_update(ZTOI(dzp), dl->dl_name, vp);
#endif /* HAVE_DNLC */
return (0);
}
static int
zfs_dropname(zfs_dirlock_t *dl, znode_t *zp, znode_t *dzp, dmu_tx_t *tx,
int flag)
{
int error;
if (ZTOZSB(zp)->z_norm) {
if (((ZTOZSB(zp)->z_case == ZFS_CASE_INSENSITIVE) &&
(flag & ZCIEXACT)) ||
((ZTOZSB(zp)->z_case == ZFS_CASE_MIXED) &&
!(flag & ZCILOOK)))
error = zap_remove_norm(ZTOZSB(zp)->z_os,
dzp->z_id, dl->dl_name, MT_EXACT, tx);
else
error = zap_remove_norm(ZTOZSB(zp)->z_os,
dzp->z_id, dl->dl_name, MT_FIRST, tx);
} else {
error = zap_remove(ZTOZSB(zp)->z_os,
dzp->z_id, dl->dl_name, tx);
}
return (error);
}
/*
* 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;
zfs_sb_t *zsb = ZTOZSB(dzp);
int zp_is_dir = S_ISDIR(ZTOI(zp)->i_mode);
boolean_t unlinked = B_FALSE;
sa_bulk_attr_t bulk[5];
uint64_t mtime[2], ctime[2];
int count = 0;
int error;
#ifdef HAVE_DNLC
dnlc_remove(ZTOI(dzp), dl->dl_name);
#endif /* HAVE_DNLC */
if (!(flag & ZRENAMING)) {
mutex_enter(&zp->z_lock);
if (zp_is_dir && !zfs_dirempty(zp)) {
mutex_exit(&zp->z_lock);
return (EEXIST);
}
/*
* If we get here, we are going to try to remove the object.
* First try removing the name from the directory; if that
* fails, return the error.
*/
error = zfs_dropname(dl, zp, dzp, tx, flag);
if (error != 0) {
mutex_exit(&zp->z_lock);
return (error);
}
if (zp->z_links <= zp_is_dir) {
zfs_panic_recover("zfs: link count on %lu is %u, "
"should be at least %u", zp->z_id,
(int)zp->z_links, zp_is_dir + 1);
zp->z_links = zp_is_dir + 1;
}
if (--zp->z_links == zp_is_dir) {
zp->z_unlinked = B_TRUE;
zp->z_links = 0;
unlinked = B_TRUE;
} else {
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zsb),
NULL, &ctime, sizeof (ctime));
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zsb),
NULL, &zp->z_pflags, sizeof (zp->z_pflags));
zfs_tstamp_update_setup(zp, STATE_CHANGED, mtime, ctime,
B_TRUE);
}
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zsb),
NULL, &zp->z_links, sizeof (zp->z_links));
error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
count = 0;
ASSERT(error == 0);
mutex_exit(&zp->z_lock);
} else {
error = zfs_dropname(dl, zp, dzp, tx, flag);
if (error != 0)
return (error);
}
mutex_enter(&dzp->z_lock);
dzp->z_size--; /* one dirent removed */
dzp->z_links -= zp_is_dir; /* ".." link from zp */
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zsb),
NULL, &dzp->z_links, sizeof (dzp->z_links));
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zsb),
NULL, &dzp->z_size, sizeof (dzp->z_size));
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zsb),
NULL, ctime, sizeof (ctime));
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zsb),
NULL, mtime, sizeof (mtime));
SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zsb),
NULL, &dzp->z_pflags, sizeof (dzp->z_pflags));
zfs_tstamp_update_setup(dzp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx);
ASSERT(error == 0);
mutex_exit(&dzp->z_lock);
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_size == 2 && dzp->z_dirlocks == 0);
}
int
zfs_make_xattrdir(znode_t *zp, vattr_t *vap, struct inode **xipp, cred_t *cr)
{
zfs_sb_t *zsb = ZTOZSB(zp);
znode_t *xzp;
dmu_tx_t *tx;
int error;
zfs_acl_ids_t acl_ids;
boolean_t fuid_dirtied;
#ifdef DEBUG
uint64_t parent;
#endif
*xipp = 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(zsb, &acl_ids)) {
zfs_acl_ids_free(&acl_ids);
return (EDQUOT);
}
top:
tx = dmu_tx_create(zsb->z_os);
dmu_tx_hold_sa_create(tx, acl_ids.z_aclp->z_acl_bytes +
ZFS_SA_BASE_ATTR_SIZE);
dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);
dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
fuid_dirtied = zsb->z_fuid_dirty;
if (fuid_dirtied)
zfs_fuid_txhold(zsb, tx);
error = dmu_tx_assign(tx, TXG_NOWAIT);
if (error) {
if (error == ERESTART) {
dmu_tx_wait(tx);
dmu_tx_abort(tx);
goto top;
}
zfs_acl_ids_free(&acl_ids);
dmu_tx_abort(tx);
return (error);
}
zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, &acl_ids);
if (fuid_dirtied)
zfs_fuid_sync(zsb, tx);
#ifdef DEBUG
error = sa_lookup(xzp->z_sa_hdl, SA_ZPL_PARENT(zsb),
&parent, sizeof (parent));
ASSERT(error == 0 && parent == zp->z_id);
#endif
VERIFY(0 == sa_update(zp->z_sa_hdl, SA_ZPL_XATTR(zsb), &xzp->z_id,
sizeof (xzp->z_id), tx));
(void) zfs_log_create(zsb->z_log, tx, TX_MKXATTR, zp,
xzp, "", NULL, acl_ids.z_fuidp, vap);
zfs_acl_ids_free(&acl_ids);
dmu_tx_commit(tx);
*xipp = ZTOI(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: xipp - pointer to extended attribute znode
*
* RETURN: 0 on success
* error number on failure
*/
int
zfs_get_xattrdir(znode_t *zp, struct inode **xipp, cred_t *cr, int flags)
{
zfs_sb_t *zsb = ZTOZSB(zp);
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) {
*xipp = ZTOI(xzp);
zfs_dirent_unlock(dl);
return (0);
}
if (!(flags & CREATE_XATTR_DIR)) {
zfs_dirent_unlock(dl);
return (ENOENT);
}
if (zsb->z_vfs->mnt_flags & MNT_READONLY) {
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 = ATTR_MODE | ATTR_UID | ATTR_GID;
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, xipp, 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;
zfs_sb_t *zsb = ZTOZSB(zdp);
if (zsb->z_replay)
return (0);
if ((zdp->z_mode & S_ISVTX) == 0)
return (0);
downer = zfs_fuid_map_id(zsb, zdp->z_uid, cr, ZFS_OWNER);
fowner = zfs_fuid_map_id(zsb, zp->z_uid, cr, ZFS_OWNER);
if ((uid = crgetuid(cr)) == downer || uid == fowner ||
(S_ISDIR(ZTOI(zp)->i_mode) &&
zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0))
return (0);
else
return (secpolicy_vnode_remove(cr));
}
Reference in New Issue View Git Blame Copy Permalink