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-rw-r--r--uts/common/fs/zfs/zfs_dir.c1089
1 files changed, 1089 insertions, 0 deletions
diff --git a/uts/common/fs/zfs/zfs_dir.c b/uts/common/fs/zfs/zfs_dir.c
new file mode 100644
index 000000000000..b06d29ab33e1
--- /dev/null
+++ b/uts/common/fs/zfs/zfs_dir.c
@@ -0,0 +1,1089 @@
+/*
+ * 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_ctldir.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(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
+ * 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)
+{
+ 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.
+ *
+ * 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(zfsvfs), &zoid,
+ sizeof (zoid));
+ if (error == 0)
+ 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);
+
+ 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, vnode_t **vpp, 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)) {
+ *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 ((error = sa_lookup(dzp->z_sa_hdl,
+ SA_ZPL_PARENT(zfsvfs), &parent, sizeof (parent))) != 0)
+ return (error);
+ if (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, 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);
+ ASSERT(zp->z_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_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, zfsvfs->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);
+ 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;
+ uint64_t xattr_obj;
+ int error;
+
+ ASSERT(zp->z_links == 0);
+ ASSERT(ZTOV(zp)->v_count == 0);
+
+ /*
+ * If this is an attribute directory, purge its contents.
+ */
+ if (ZTOV(zp)->v_type == VDIR && (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_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.
+ */
+ error = sa_lookup(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs),
+ &xattr_obj, sizeof (xattr_obj));
+ if (error == 0 && xattr_obj) {
+ error = zfs_zget(zfsvfs, 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, zfsvfs->z_unlinkedobj, FALSE, NULL);
+ if (xzp) {
+ dmu_tx_hold_zap(tx, zfsvfs->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_znode_free(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(zfsvfs),
+ &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(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 mode)
+{
+ uint64_t de = zp->z_id;
+
+ if (zp->z_zfsvfs->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;
+ zfsvfs_t *zfsvfs = zp->z_zfsvfs;
+ vnode_t *vp = ZTOV(zp);
+ uint64_t value;
+ int zp_is_dir = (vp->v_type == VDIR);
+ 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(zfsvfs), NULL,
+ &zp->z_links, sizeof (zp->z_links));
+
+ }
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zfsvfs), NULL,
+ &dzp->z_id, sizeof (dzp->z_id));
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
+ &zp->z_pflags, sizeof (zp->z_pflags));
+
+ if (!(flag & ZNEW)) {
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), 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(zfsvfs), NULL,
+ &dzp->z_size, sizeof (dzp->z_size));
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
+ &dzp->z_links, sizeof (dzp->z_links));
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL,
+ mtime, sizeof (mtime));
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
+ ctime, sizeof (ctime));
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), 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(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);
+}
+
+static int
+zfs_dropname(zfs_dirlock_t *dl, znode_t *zp, znode_t *dzp, dmu_tx_t *tx,
+ int flag)
+{
+ int error;
+
+ 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);
+ }
+
+ 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;
+ zfsvfs_t *zfsvfs = dzp->z_zfsvfs;
+ vnode_t *vp = ZTOV(zp);
+ int zp_is_dir = (vp->v_type == VDIR);
+ boolean_t unlinked = B_FALSE;
+ sa_bulk_attr_t bulk[5];
+ uint64_t mtime[2], ctime[2];
+ int count = 0;
+ int error;
+
+ dnlc_remove(ZTOV(dzp), dl->dl_name);
+
+ if (!(flag & ZRENAMING)) {
+ 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)) {
+ mutex_exit(&zp->z_lock);
+ vn_vfsunlock(vp);
+ 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);
+ vn_vfsunlock(vp);
+ return (error);
+ }
+
+ if (zp->z_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_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(zfsvfs),
+ NULL, &ctime, sizeof (ctime));
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
+ 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(zfsvfs),
+ 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);
+ vn_vfsunlock(vp);
+ } 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(zfsvfs),
+ NULL, &dzp->z_links, sizeof (dzp->z_links));
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs),
+ NULL, &dzp->z_size, sizeof (dzp->z_size));
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs),
+ NULL, ctime, sizeof (ctime));
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs),
+ NULL, mtime, sizeof (mtime));
+ SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
+ 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, 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;
+ uint64_t parent;
+
+ *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);
+ }
+
+top:
+ tx = dmu_tx_create(zfsvfs->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 = zfsvfs->z_fuid_dirty;
+ if (fuid_dirtied)
+ zfs_fuid_txhold(zfsvfs, 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(zfsvfs, tx);
+
+#ifdef DEBUG
+ error = sa_lookup(xzp->z_sa_hdl, SA_ZPL_PARENT(zfsvfs),
+ &parent, sizeof (parent));
+ ASSERT(error == 0 && parent == zp->z_id);
+#endif
+
+ VERIFY(0 == sa_update(zp->z_sa_hdl, SA_ZPL_XATTR(zfsvfs), &xzp->z_id,
+ sizeof (xzp->z_id), tx));
+
+ (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);
+ }
+
+
+ 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_mode & S_ISVTX) == 0)
+ return (0);
+
+ downer = zfs_fuid_map_id(zfsvfs, zdp->z_uid, cr, ZFS_OWNER);
+ fowner = zfs_fuid_map_id(zfsvfs, zp->z_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));
+}