/* * 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 https://opensource.org/licenses/CDDL-1.0. * 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. * Copyright (c) 2013, 2016 by Delphix. All rights reserved. * Copyright 2017 Nexenta Systems, Inc. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* * zfs_match_find() is used by zfs_dirent_lock() to perform zap lookups * of names after deciding which is the appropriate lookup interface. */ static int zfs_match_find(zfsvfs_t *zfsvfs, znode_t *dzp, const char *name, matchtype_t mt, boolean_t update, int *deflags, pathname_t *rpnp, uint64_t *zoid) { boolean_t conflict = B_FALSE; int error; if (zfsvfs->z_norm) { size_t bufsz = 0; char *buf = NULL; if (rpnp) { buf = rpnp->pn_buf; bufsz = rpnp->pn_bufsize; } /* * 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); } else { error = zap_lookup(zfsvfs->z_os, dzp->z_id, name, 8, 1, zoid); } /* * Allow multiple entries provided the first entry is * the object id. Non-zpl consumers may safely make * use of the additional space. * * XXX: This should be a feature flag for compatibility */ if (error == EOVERFLOW) error = 0; if (zfsvfs->z_norm && !error && deflags) *deflags = conflict ? ED_CASE_CONFLICT : 0; *zoid = ZFS_DIRENT_OBJ(*zoid); return (error); } /* * Lock a directory entry. A dirlock on 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 = ZTOZSB(dzp); zfs_dirlock_t *dl; boolean_t update; matchtype_t mt = 0; uint64_t zoid; 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 (SET_ERROR(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. */ /* * When matching we may need to normalize & change case according to * FS settings. * * Note that a normalized match is necessary for a case insensitive * filesystem when the lookup request is not exact because normalization * can fold case independent of normalizing code point sequences. * * See the table above zfs_dropname(). */ if (zfsvfs->z_norm != 0) { mt = MT_NORMALIZE; /* * Determine if the match needs to honor the case specified in * lookup, and if so keep track of that so that during * normalization we don't fold case. */ if ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE && (flag & ZCIEXACT)) || (zfsvfs->z_case == ZFS_CASE_MIXED && !(flag & ZCILOOK))) { mt |= MT_MATCH_CASE; } } /* * 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 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 && !(flag & ZXATTR)) { mutex_exit(&dzp->z_lock); if (!(flag & ZHAVELOCK)) rw_exit(&dzp->z_name_lock); return (SET_ERROR(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 (SET_ERROR(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. It'll either see the old value, * which belongs to it, or the new shared copy; either is OK. */ dl->dl_namesize = strlen(dl->dl_name) + 1; name = kmem_alloc(dl->dl_namesize, KM_SLEEP); memcpy(name, dl->dl_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 ? SET_ERROR(ENOENT) : 0); } else { error = zfs_match_find(zfsvfs, dzp, name, mt, 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 (SET_ERROR(EEXIST)); } error = zfs_zget(zfsvfs, zoid, zpp); if (error) { zfs_dirent_unlock(dl); return (error); } } *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, znode_t **zpp, int flags, int *deflg, pathname_t *rpnp) { zfs_dirlock_t *dl; znode_t *zp; struct inode *ip; int error = 0; uint64_t parent; if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) { *zpp = dzp; zhold(*zpp); } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) { zfsvfs_t *zfsvfs = ZTOZSB(dzp); /* * If we are a snapshot mounted under .zfs, return * the inode pointer 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", &ip, 0, kcred, NULL, NULL); *zpp = ITOZ(ip); return (error); } rw_enter(&dzp->z_parent_lock, RW_READER); error = zfs_zget(zfsvfs, parent, &zp); if (error == 0) *zpp = zp; rw_exit(&dzp->z_parent_lock); } else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) { if (ZTOZSB(dzp)->z_show_ctldir == ZFS_SNAPDIR_DISABLED) { return (SET_ERROR(ENOENT)); } ip = zfsctl_root(dzp); *zpp = ITOZ(ip); } 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) { *zpp = 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 = ZTOZSB(zp); ASSERT(zp->z_unlinked); ASSERT(ZTOI(zp)->i_nlink == 0); VERIFY3U(0, ==, zap_add_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx)); dataset_kstats_update_nunlinks_kstat(&zfsvfs->z_kstat, 1); } /* * Clean up any znodes that had no links when we either crashed or * (force) umounted the file system. */ static void zfs_unlinked_drain_task(void *arg) { zfsvfs_t *zfsvfs = arg; zap_cursor_t zc; zap_attribute_t *zap = zap_attribute_alloc(); dmu_object_info_t doi; znode_t *zp; int error; ASSERT3B(zfsvfs->z_draining, ==, B_TRUE); /* * Iterate over the contents of the unlinked set. */ for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj); zap_cursor_retrieve(&zc, zap) == 0 && !zfsvfs->z_drain_cancel; 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; /* * zrele() decrements the znode's ref count and may cause * it to be synchronously freed. We interrupt freeing * of this znode by checking the return value of * dmu_objset_zfs_unmounting() in dmu_free_long_range() * when an unmount is requested. */ zrele(zp); ASSERT3B(zfsvfs->z_unmounted, ==, B_FALSE); } zap_cursor_fini(&zc); zfsvfs->z_draining = B_FALSE; zfsvfs->z_drain_task = TASKQID_INVALID; zap_attribute_free(zap); } /* * Sets z_draining then tries to dispatch async unlinked drain. * If that fails executes synchronous unlinked drain. */ void zfs_unlinked_drain(zfsvfs_t *zfsvfs) { ASSERT3B(zfsvfs->z_unmounted, ==, B_FALSE); ASSERT3B(zfsvfs->z_draining, ==, B_FALSE); zfsvfs->z_draining = B_TRUE; zfsvfs->z_drain_cancel = B_FALSE; zfsvfs->z_drain_task = taskq_dispatch( dsl_pool_unlinked_drain_taskq(dmu_objset_pool(zfsvfs->z_os)), zfs_unlinked_drain_task, zfsvfs, TQ_SLEEP); if (zfsvfs->z_drain_task == TASKQID_INVALID) { zfs_dbgmsg("async zfs_unlinked_drain dispatch failed"); zfs_unlinked_drain_task(zfsvfs); } } /* * Wait for the unlinked drain taskq task to stop. This will interrupt the * unlinked set processing if it is in progress. */ void zfs_unlinked_drain_stop_wait(zfsvfs_t *zfsvfs) { ASSERT3B(zfsvfs->z_unmounted, ==, B_FALSE); if (zfsvfs->z_draining) { zfsvfs->z_drain_cancel = B_TRUE; taskq_cancel_id(dsl_pool_unlinked_drain_taskq( dmu_objset_pool(zfsvfs->z_os)), zfsvfs->z_drain_task); zfsvfs->z_drain_task = TASKQID_INVALID; zfsvfs->z_draining = B_FALSE; } } /* * 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 = zap_attribute_alloc(); znode_t *xzp; dmu_tx_t *tx; zfsvfs_t *zfsvfs = ZTOZSB(dzp); 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(S_ISREG(ZTOI(xzp)->i_mode) || S_ISLNK(ZTOI(xzp)->i_mode)); 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); dmu_tx_mark_netfree(tx); error = dmu_tx_assign(tx, TXG_WAIT); if (error) { dmu_tx_abort(tx); zfs_zrele_async(xzp); skipped += 1; continue; } memset(&dl, 0, 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); zfs_zrele_async(xzp); } zap_cursor_fini(&zc); zap_attribute_free(zap); if (error != ENOENT) skipped += 1; return (skipped); } void zfs_rmnode(znode_t *zp) { zfsvfs_t *zfsvfs = ZTOZSB(zp); objset_t *os = zfsvfs->z_os; znode_t *xzp = NULL; dmu_tx_t *tx; znode_hold_t *zh; uint64_t z_id = zp->z_id; uint64_t acl_obj; uint64_t xattr_obj; uint64_t links; int error; ASSERT(ZTOI(zp)->i_nlink == 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. */ zh = zfs_znode_hold_enter(zfsvfs, z_id); zfs_znode_dmu_fini(zp); zfs_znode_hold_exit(zfsvfs, zh); return; } } /* * Free up all the data in the file. We don't do this for directories * because we need truncate and remove to be in the same tx, like in * zfs_znode_delete(). Otherwise, if we crash here we'll end up with * an inconsistent truncated zap object in the delete queue. Note a * truncated file is harmless since it only contains user data. */ if (S_ISREG(ZTOI(zp)->i_mode)) { error = dmu_free_long_range(os, zp->z_id, 0, DMU_OBJECT_END); if (error) { /* * Not enough space or we were interrupted by unmount. * Leave the file in the unlinked set. */ zh = zfs_znode_hold_enter(zfsvfs, z_id); zfs_znode_dmu_fini(zp); zfs_znode_hold_exit(zfsvfs, zh); 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); zh = zfs_znode_hold_enter(zfsvfs, z_id); zfs_znode_dmu_fini(zp); zfs_znode_hold_exit(zfsvfs, zh); goto out; } if (xzp) { ASSERT(error == 0); mutex_enter(&xzp->z_lock); xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */ clear_nlink(ZTOI(xzp)); /* no more links to it */ links = 0; VERIFY(0 == sa_update(xzp->z_sa_hdl, SA_ZPL_LINKS(zfsvfs), &links, sizeof (links), tx)); mutex_exit(&xzp->z_lock); zfs_unlinked_add(xzp, tx); } mutex_enter(&os->os_dsl_dataset->ds_dir->dd_activity_lock); /* * Remove this znode from the unlinked set. If a has rollback has * occurred while a file is open and unlinked. Then when the file * is closed post rollback it will not exist in the rolled back * version of the unlinked object. */ error = zap_remove_int(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zp->z_id, tx); VERIFY(error == 0 || error == ENOENT); uint64_t count; if (zap_count(os, zfsvfs->z_unlinkedobj, &count) == 0 && count == 0) { cv_broadcast(&os->os_dsl_dataset->ds_dir->dd_activity_cv); } mutex_exit(&os->os_dsl_dataset->ds_dir->dd_activity_lock); dataset_kstats_update_nunlinked_kstat(&zfsvfs->z_kstat, 1); zfs_znode_delete(zp, tx); dmu_tx_commit(tx); out: if (xzp) zfs_zrele_async(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 fail in the following cases : * - if zp has been unlinked. * - if the number of entries with the same hash (aka. colliding entries) * exceed the capacity of a leaf-block of fatzap and splitting of the * leaf-block does not help. */ 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 = 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]; uint64_t links; 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 (SET_ERROR(ENOENT)); } if (!(flag & ZNEW)) { /* * ZNEW nodes come from zfs_mknode() where the link * count has already been initialised */ inc_nlink(ZTOI(zp)); links = ZTOI(zp)->i_nlink; SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL, &links, sizeof (links)); } } value = zfs_dirent(zp, zp->z_mode); error = zap_add(ZTOZSB(zp)->z_os, dzp->z_id, dl->dl_name, 8, 1, &value, tx); /* * zap_add could fail to add the entry if it exceeds the capacity of the * leaf-block and zap_leaf_split() failed to help. * The caller of this routine is responsible for failing the transaction * which will rollback the SA updates done above. */ if (error != 0) { if (!(flag & ZRENAMING) && !(flag & ZNEW)) drop_nlink(ZTOI(zp)); mutex_exit(&zp->z_lock); return (error); } /* * If we added a longname activate the SPA_FEATURE_LONGNAME. */ if (strlen(dl->dl_name) >= ZAP_MAXNAMELEN) { dsl_dataset_t *ds = dmu_objset_ds(zfsvfs->z_os); ds->ds_feature_activation[SPA_FEATURE_LONGNAME] = (void *)B_TRUE; } 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); } 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++; if (zp_is_dir) inc_nlink(ZTOI(dzp)); links = ZTOI(dzp)->i_nlink; 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, &links, sizeof (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); error = sa_bulk_update(dzp->z_sa_hdl, bulk, count, tx); ASSERT(error == 0); mutex_exit(&dzp->z_lock); return (0); } /* * The match type in the code for this function should conform to: * * ------------------------------------------------------------------------ * fs type | z_norm | lookup type | match type * ---------|-------------|-------------|---------------------------------- * CS !norm | 0 | 0 | 0 (exact) * CS norm | formX | 0 | MT_NORMALIZE * CI !norm | upper | !ZCIEXACT | MT_NORMALIZE * CI !norm | upper | ZCIEXACT | MT_NORMALIZE | MT_MATCH_CASE * CI norm | upper|formX | !ZCIEXACT | MT_NORMALIZE * CI norm | upper|formX | ZCIEXACT | MT_NORMALIZE | MT_MATCH_CASE * CM !norm | upper | !ZCILOOK | MT_NORMALIZE | MT_MATCH_CASE * CM !norm | upper | ZCILOOK | MT_NORMALIZE * CM norm | upper|formX | !ZCILOOK | MT_NORMALIZE | MT_MATCH_CASE * CM norm | upper|formX | ZCILOOK | MT_NORMALIZE * * Abbreviations: * CS = Case Sensitive, CI = Case Insensitive, CM = Case Mixed * upper = case folding set by fs type on creation (U8_TEXTPREP_TOUPPER) * formX = unicode normalization form set on fs creation */ 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) { matchtype_t mt = MT_NORMALIZE; if ((ZTOZSB(zp)->z_case == ZFS_CASE_INSENSITIVE && (flag & ZCIEXACT)) || (ZTOZSB(zp)->z_case == ZFS_CASE_MIXED && !(flag & ZCILOOK))) { mt |= MT_MATCH_CASE; } error = zap_remove_norm(ZTOZSB(zp)->z_os, dzp->z_id, dl->dl_name, mt, tx); } else { error = zap_remove(ZTOZSB(zp)->z_os, dzp->z_id, dl->dl_name, tx); } return (error); } static int zfs_drop_nlink_locked(znode_t *zp, dmu_tx_t *tx, boolean_t *unlinkedp) { zfsvfs_t *zfsvfs = ZTOZSB(zp); int zp_is_dir = S_ISDIR(ZTOI(zp)->i_mode); boolean_t unlinked = B_FALSE; sa_bulk_attr_t bulk[3]; uint64_t mtime[2], ctime[2]; uint64_t links; int count = 0; int error; if (zp_is_dir && !zfs_dirempty(zp)) return (SET_ERROR(ENOTEMPTY)); if (ZTOI(zp)->i_nlink <= zp_is_dir) { zfs_panic_recover("zfs: link count on %lu is %u, " "should be at least %u", zp->z_id, (int)ZTOI(zp)->i_nlink, zp_is_dir + 1); set_nlink(ZTOI(zp), zp_is_dir + 1); } drop_nlink(ZTOI(zp)); if (ZTOI(zp)->i_nlink == zp_is_dir) { zp->z_unlinked = B_TRUE; clear_nlink(ZTOI(zp)); 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); } links = ZTOI(zp)->i_nlink; SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL, &links, sizeof (links)); error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx); ASSERT3U(error, ==, 0); if (unlinkedp != NULL) *unlinkedp = unlinked; else if (unlinked) zfs_unlinked_add(zp, tx); return (0); } /* * Forcefully drop an nlink reference from (zp) and mark it for deletion if it * was the last link. This *must* only be done to znodes which have already * been zfs_link_destroy()'d with ZRENAMING. This is explicitly only used in * the error path of zfs_rename(), where we have to correct the nlink count if * we failed to link the target as well as failing to re-link the original * znodes. */ int zfs_drop_nlink(znode_t *zp, dmu_tx_t *tx, boolean_t *unlinkedp) { int error; mutex_enter(&zp->z_lock); error = zfs_drop_nlink_locked(zp, tx, unlinkedp); mutex_exit(&zp->z_lock); 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 (ENOTEMPTY). * 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 = 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]; uint64_t links; int count = 0; int error; if (!(flag & ZRENAMING)) { mutex_enter(&zp->z_lock); if (zp_is_dir && !zfs_dirempty(zp)) { mutex_exit(&zp->z_lock); return (SET_ERROR(ENOTEMPTY)); } /* * 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); } /* The only error is !zfs_dirempty() and we checked earlier. */ error = zfs_drop_nlink_locked(zp, tx, &unlinked); ASSERT3U(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 */ if (zp_is_dir) drop_nlink(ZTOI(dzp)); /* ".." link from zp */ links = ZTOI(dzp)->i_nlink; SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL, &links, sizeof (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); 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. * * The internal ZAP size, rather than zp->z_size, needs to be checked since * some consumers (Lustre) do not strictly maintain an accurate SA_ZPL_SIZE. */ boolean_t zfs_dirempty(znode_t *dzp) { zfsvfs_t *zfsvfs = ZTOZSB(dzp); uint64_t count; int error; if (dzp->z_dirlocks != NULL) return (B_FALSE); error = zap_count(zfsvfs->z_os, dzp->z_id, &count); if (error != 0 || count != 0) return (B_FALSE); return (B_TRUE); } int zfs_make_xattrdir(znode_t *zp, vattr_t *vap, znode_t **xzpp, cred_t *cr) { zfsvfs_t *zfsvfs = ZTOZSB(zp); znode_t *xzp; dmu_tx_t *tx; int error; zfs_acl_ids_t acl_ids; boolean_t fuid_dirtied; #ifdef ZFS_DEBUG uint64_t parent; #endif *xzpp = NULL; if ((error = zfs_acl_ids_create(zp, IS_XATTR, vap, cr, NULL, &acl_ids, zfs_init_idmap)) != 0) return (error); if (zfs_acl_ids_overquota(zfsvfs, &acl_ids, zp->z_projid)) { zfs_acl_ids_free(&acl_ids); return (SET_ERROR(EDQUOT)); } 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_WAIT); if (error) { 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 ZFS_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)); if (!zp->z_unlinked) 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); *xzpp = 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, znode_t **xzpp, cred_t *cr, int flags) { zfsvfs_t *zfsvfs = 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) { *xzpp = xzp; zfs_dirent_unlock(dl); return (0); } if (!(flags & CREATE_XATTR_DIR)) { zfs_dirent_unlock(dl); return (SET_ERROR(ENOENT)); } if (zfs_is_readonly(zfsvfs)) { zfs_dirent_unlock(dl); return (SET_ERROR(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); va.va_dentry = NULL; error = zfs_make_xattrdir(zp, &va, xzpp, 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, * you have write access to the entry, * 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 = ZTOZSB(zdp); if (zfsvfs->z_replay) return (0); if ((zdp->z_mode & S_ISVTX) == 0) return (0); downer = zfs_fuid_map_id(zfsvfs, KUID_TO_SUID(ZTOI(zdp)->i_uid), cr, ZFS_OWNER); fowner = zfs_fuid_map_id(zfsvfs, KUID_TO_SUID(ZTOI(zp)->i_uid), cr, ZFS_OWNER); if ((uid = crgetuid(cr)) == downer || uid == fowner || zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr, zfs_init_idmap) == 0) return (0); else return (secpolicy_vnode_remove(cr)); }