/* * 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 2008 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #pragma ident "%Z%%M% %I% %E% SMI" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "fs/fs_subr.h" #include #include #include #include #include #include #include /* * 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_path; 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 (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 protects that name * in dzp's directory zap object. As long as you hold a dirlock, you can * assume two things: (1) dzp cannot be reaped, and (2) no other thread * can change the zap entry for (i.e. link or unlink) this name. * * Input arguments: * dzp - znode for directory * name - name of entry to lock * flag - ZNEW: if the entry already exists, fail with EEXIST. * ZEXISTS: if the entry does not exist, fail with ENOENT. * ZSHARED: allow concurrent access with other ZSHARED callers. * ZXATTR: we want dzp's xattr directory * ZCILOOK: On a mixed sensitivity file system, * this lookup should be case-insensitive. * ZCIEXACT: On a purely case-insensitive file system, * this lookup should be case-sensitive. * ZRENAMING: we are locking for renaming, force narrow locks * * Output arguments: * zpp - pointer to the znode for the entry (NULL if there isn't one) * dlpp - pointer to the dirlock for this entry (NULL on error) * direntflags - (case-insensitive lookup only) * flags if multiple case-sensitive matches exist in directory * realpnp - (case-insensitive lookup only) * actual name matched within the directory * * Return value: 0 on success or errno on failure. * * NOTE: Always checks for, and rejects, '.' and '..'. * NOTE: For case-insensitive file systems we take wide locks (see below), * but return znode pointers to a single match. */ int zfs_dirent_lock(zfs_dirlock_t **dlpp, znode_t *dzp, char *name, znode_t **zpp, int flag, int *direntflags, pathname_t *realpnp) { zfsvfs_t *zfsvfs = dzp->z_zfsvfs; zfs_dirlock_t *dl; boolean_t update; boolean_t exact; uint64_t zoid; vnode_t *vp = NULL; int error = 0; int cmpflags; *zpp = NULL; *dlpp = NULL; /* * Verify that we are not trying to lock '.', '..', or '.zfs' */ if (name[0] == '.' && (name[1] == '\0' || (name[1] == '.' && name[2] == '\0')) || zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) return (EEXIST); /* * Case sensitivity and normalization preferences are set when * the file system is created. These are stored in the * zfsvfs->z_case and zfsvfs->z_norm fields. These choices * affect what vnodes can be cached in the DNLC, how we * perform zap lookups, and the "width" of our dirlocks. * * A normal dirlock locks a single name. Note that with * normalization a name can be composed multiple ways, but * when normalized, these names all compare equal. A wide * dirlock locks multiple names. We need these when the file * system is supporting mixed-mode access. It is sometimes * necessary to lock all case permutations of file name at * once so that simultaneous case-insensitive/case-sensitive * behaves as rationally as possible. */ /* * Decide if exact matches should be requested when performing * a zap lookup on file systems supporting case-insensitive * access. */ exact = ((zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && (flag & ZCIEXACT)) || ((zfsvfs->z_case == ZFS_CASE_MIXED) && !(flag & ZCILOOK)); /* * Only look in or update the DNLC if we are looking for the * name on a file system that does not require normalization * or case folding. We can also look there if we happen to be * on a non-normalizing, mixed sensitivity file system IF we * are looking for the exact name. * * Maybe can add TO-UPPERed version of name to dnlc in ci-only * case for performance improvement? */ update = !zfsvfs->z_norm || ((zfsvfs->z_case == ZFS_CASE_MIXED) && !(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER) && !(flag & ZCILOOK)); /* * ZRENAMING indicates we are in a situation where we should * take narrow locks regardless of the file system's * preferences for normalizing and case folding. This will * prevent us deadlocking trying to grab the same wide lock * twice if the two names happen to be case-insensitive * matches. */ if (flag & ZRENAMING) cmpflags = 0; else cmpflags = zfsvfs->z_norm; /* * Wait until there are no locks on this name. */ rw_enter(&dzp->z_name_lock, RW_READER); mutex_enter(&dzp->z_lock); for (;;) { if (dzp->z_unlinked) { mutex_exit(&dzp->z_lock); rw_exit(&dzp->z_name_lock); return (ENOENT); } for (dl = dzp->z_dirlocks; dl != NULL; dl = dl->dl_next) { if ((u8_strcmp(name, dl->dl_name, 0, cmpflags, U8_UNICODE_LATEST, &error) == 0) || error != 0) break; } if (error != 0) { mutex_exit(&dzp->z_lock); rw_exit(&dzp->z_name_lock); return (ENOENT); } if (dl == NULL) { /* * Allocate a new dirlock and add it to the list. */ dl = kmem_alloc(sizeof (zfs_dirlock_t), KM_SLEEP); cv_init(&dl->dl_cv, NULL, CV_DEFAULT, NULL); dl->dl_name = name; dl->dl_sharecnt = 0; dl->dl_namesize = 0; dl->dl_dzp = dzp; dl->dl_next = dzp->z_dirlocks; dzp->z_dirlocks = dl; break; } if ((flag & ZSHARED) && dl->dl_sharecnt != 0) break; cv_wait(&dl->dl_cv, &dzp->z_lock); } if ((flag & ZSHARED) && ++dl->dl_sharecnt > 1 && dl->dl_namesize == 0) { /* * We're the second shared reference to dl. Make a copy of * dl_name in case the first thread goes away before we do. * Note that we initialize the new name before storing its * pointer into dl_name, because the first thread may load * dl->dl_name at any time. He'll either see the old value, * which is his, or the new shared copy; either is OK. */ dl->dl_namesize = strlen(dl->dl_name) + 1; name = kmem_alloc(dl->dl_namesize, KM_SLEEP); bcopy(dl->dl_name, name, dl->dl_namesize); dl->dl_name = name; } mutex_exit(&dzp->z_lock); /* * We have a dirlock on the name. (Note that it is the dirlock, * not the dzp's z_lock, that protects the name in the zap object.) * See if there's an object by this name; if so, put a hold on it. */ if (flag & ZXATTR) { zoid = dzp->z_phys->zp_xattr; error = (zoid == 0 ? ENOENT : 0); } else { if (update) vp = dnlc_lookup(ZTOV(dzp), name); if (vp == DNLC_NO_VNODE) { VN_RELE(vp); error = ENOENT; } else if (vp) { if (flag & ZNEW) { zfs_dirent_unlock(dl); VN_RELE(vp); return (EEXIST); } *dlpp = dl; *zpp = VTOZ(vp); return (0); } else { error = zfs_match_find(zfsvfs, dzp, name, exact, update, direntflags, realpnp, &zoid); } } if (error) { if (error != ENOENT || (flag & ZEXISTS)) { zfs_dirent_unlock(dl); return (error); } } else { if (flag & ZNEW) { zfs_dirent_unlock(dl); return (EEXIST); } error = zfs_zget(zfsvfs, zoid, zpp); if (error) { zfs_dirent_unlock(dl); return (error); } if (!(flag & ZXATTR) && update) dnlc_update(ZTOV(dzp), name, ZTOV(*zpp)); } *dlpp = dl; return (0); } /* * Unlock this directory entry and wake anyone who was waiting for it. */ void zfs_dirent_unlock(zfs_dirlock_t *dl) { znode_t *dzp = dl->dl_dzp; zfs_dirlock_t **prev_dl, *cur_dl; mutex_enter(&dzp->z_lock); rw_exit(&dzp->z_name_lock); if (dl->dl_sharecnt > 1) { dl->dl_sharecnt--; mutex_exit(&dzp->z_lock); return; } prev_dl = &dzp->z_dirlocks; while ((cur_dl = *prev_dl) != dl) prev_dl = &cur_dl->dl_next; *prev_dl = dl->dl_next; cv_broadcast(&dl->dl_cv); mutex_exit(&dzp->z_lock); if (dl->dl_namesize != 0) kmem_free(dl->dl_name, dl->dl_namesize); cv_destroy(&dl->dl_cv); kmem_free(dl, sizeof (*dl)); } /* * Look up an entry in a directory. * * NOTE: '.' and '..' are handled as special cases because * no directory entries are actually stored for them. If this is * the root of a filesystem, then '.zfs' is also treated as a * special pseudo-directory. */ int zfs_dirlook(znode_t *dzp, char *name, vnode_t **vpp, int flags, int *deflg, pathname_t *rpnp) { zfs_dirlock_t *dl; znode_t *zp; int error = 0; if (name[0] == 0 || (name[0] == '.' && name[1] == 0)) { *vpp = ZTOV(dzp); VN_HOLD(*vpp); } else if (name[0] == '.' && name[1] == '.' && name[2] == 0) { zfsvfs_t *zfsvfs = dzp->z_zfsvfs; /* * If we are a snapshot mounted under .zfs, return * the vp for the snapshot directory. */ if (dzp->z_phys->zp_parent == dzp->z_id && zfsvfs->z_parent != zfsvfs) { error = zfsctl_root_lookup(zfsvfs->z_parent->z_ctldir, "snapshot", vpp, NULL, 0, NULL, kcred, NULL, NULL, NULL); return (error); } rw_enter(&dzp->z_parent_lock, RW_READER); error = zfs_zget(zfsvfs, dzp->z_phys->zp_parent, &zp); if (error == 0) *vpp = ZTOV(zp); rw_exit(&dzp->z_parent_lock); } else if (zfs_has_ctldir(dzp) && strcmp(name, ZFS_CTLDIR_NAME) == 0) { *vpp = zfsctl_root(dzp); } else { int zf; zf = ZEXISTS | ZSHARED; if (flags & FIGNORECASE) zf |= ZCILOOK; error = zfs_dirent_lock(&dl, dzp, name, &zp, zf, deflg, rpnp); if (error == 0) { *vpp = ZTOV(zp); zfs_dirent_unlock(dl); dzp->z_zn_prefetch = B_TRUE; /* enable prefetching */ } rpnp = NULL; } if ((flags & FIGNORECASE) && rpnp) (void) strlcpy(rpnp->pn_path, name, rpnp->pn_bufsize); return (error); } static char * zfs_unlinked_hexname(char namebuf[17], uint64_t x) { char *name = &namebuf[16]; const char digits[16] = "0123456789abcdef"; *name = '\0'; do { *--name = digits[x & 0xf]; x >>= 4; } while (x != 0); return (name); } /* * 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; char obj_name[17]; int error; ASSERT(zp->z_unlinked); ASSERT3U(zp->z_phys->zp_links, ==, 0); error = zap_add(zfsvfs->z_os, zfsvfs->z_unlinkedobj, zfs_unlinked_hexname(obj_name, zp->z_id), 8, 1, &zp->z_id, tx); ASSERT3U(error, ==, 0); } /* * Clean up any znodes that had no links when we either crashed or * (force) umounted the file system. */ void zfs_unlinked_drain(zfsvfs_t *zfsvfs) { zap_cursor_t zc; zap_attribute_t zap; dmu_object_info_t doi; znode_t *zp; int error; /* * Interate over the contents of the unlinked set. */ for (zap_cursor_init(&zc, zfsvfs->z_os, zfsvfs->z_unlinkedobj); zap_cursor_retrieve(&zc, &zap) == 0; zap_cursor_advance(&zc)) { /* * See what kind of object we have in list */ error = dmu_object_info(zfsvfs->z_os, zap.za_first_integer, &doi); if (error != 0) continue; ASSERT((doi.doi_type == DMU_OT_PLAIN_FILE_CONTENTS) || (doi.doi_type == DMU_OT_DIRECTORY_CONTENTS)); /* * We need to re-mark these list entries for deletion, * so we pull them back into core and set zp->z_unlinked. */ error = zfs_zget(zfsvfs, zap.za_first_integer, &zp); /* * We may pick up znodes that are already marked for deletion. * This could happen during the purge of an extended attribute * directory. All we need to do is skip over them, since they * are already in the system marked z_unlinked. */ if (error != 0) continue; zp->z_unlinked = B_TRUE; VN_RELE(ZTOV(zp)); } zap_cursor_fini(&zc); } /* * Delete the entire contents of a directory. Return a count * of the number of entries that could not be deleted. If we encounter * an error, return a count of at least one so that the directory stays * in the unlinked set. * * NOTE: this function assumes that the directory is inactive, * so there is no need to lock its entries before deletion. * Also, it assumes the directory contents is *only* regular * files. */ static int zfs_purgedir(znode_t *dzp) { zap_cursor_t zc; zap_attribute_t zap; znode_t *xzp; dmu_tx_t *tx; zfsvfs_t *zfsvfs = dzp->z_zfsvfs; zfs_dirlock_t dl; int skipped = 0; int error; for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id); (error = zap_cursor_retrieve(&zc, &zap)) == 0; zap_cursor_advance(&zc)) { error = zfs_zget(zfsvfs, ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp); if (error) { skipped += 1; continue; } ASSERT((ZTOV(xzp)->v_type == VREG) || (ZTOV(xzp)->v_type == VLNK)); tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_bonus(tx, dzp->z_id); dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name); dmu_tx_hold_bonus(tx, xzp->z_id); dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); error = dmu_tx_assign(tx, TXG_WAIT); if (error) { dmu_tx_abort(tx); VN_RELE(ZTOV(xzp)); skipped += 1; continue; } bzero(&dl, sizeof (dl)); dl.dl_dzp = dzp; dl.dl_name = zap.za_name; error = zfs_link_destroy(&dl, xzp, tx, 0, NULL); if (error) skipped += 1; dmu_tx_commit(tx); VN_RELE(ZTOV(xzp)); } zap_cursor_fini(&zc); if (error != ENOENT) skipped += 1; return (skipped); } void zfs_rmnode(znode_t *zp) { zfsvfs_t *zfsvfs = zp->z_zfsvfs; objset_t *os = zfsvfs->z_os; znode_t *xzp = NULL; char obj_name[17]; dmu_tx_t *tx; uint64_t acl_obj; int error; ASSERT(ZTOV(zp)->v_count == 0); ASSERT(zp->z_phys->zp_links == 0); /* * If this is an attribute directory, purge its contents. */ if (ZTOV(zp)->v_type == VDIR && (zp->z_phys->zp_flags & ZFS_XATTR)) { if (zfs_purgedir(zp) != 0) { /* * Not enough space to delete some xattrs. * Leave it on the unlinked set. */ zfs_znode_dmu_fini(zp); zfs_znode_free(zp); return; } } /* * If the file has extended attributes, we're going to unlink * the xattr dir. */ if (zp->z_phys->zp_xattr) { error = zfs_zget(zfsvfs, zp->z_phys->zp_xattr, &xzp); ASSERT(error == 0); } acl_obj = zp->z_phys->zp_acl.z_acl_extern_obj; /* * Set up the transaction. */ tx = dmu_tx_create(os); dmu_tx_hold_free(tx, zp->z_id, 0, DMU_OBJECT_END); dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL); if (xzp) { dmu_tx_hold_bonus(tx, xzp->z_id); dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, TRUE, NULL); } if (acl_obj) dmu_tx_hold_free(tx, acl_obj, 0, DMU_OBJECT_END); error = dmu_tx_assign(tx, TXG_WAIT); if (error) { /* * Not enough space to delete the file. Leave it in the * unlinked set, leaking it until the fs is remounted (at * which point we'll call zfs_unlinked_drain() to process it). */ dmu_tx_abort(tx); zfs_znode_dmu_fini(zp); zfs_znode_free(zp); goto out; } if (xzp) { dmu_buf_will_dirty(xzp->z_dbuf, tx); mutex_enter(&xzp->z_lock); xzp->z_unlinked = B_TRUE; /* mark xzp for deletion */ xzp->z_phys->zp_links = 0; /* no more links to it */ mutex_exit(&xzp->z_lock); zfs_unlinked_add(xzp, tx); } /* Remove this znode from the unlinked set */ error = zap_remove(os, zfsvfs->z_unlinkedobj, zfs_unlinked_hexname(obj_name, zp->z_id), tx); ASSERT3U(error, ==, 0); zfs_znode_delete(zp, tx); dmu_tx_commit(tx); out: if (xzp) VN_RELE(ZTOV(xzp)); } static uint64_t zfs_dirent(znode_t *zp) { uint64_t de = zp->z_id; if (zp->z_zfsvfs->z_version >= ZPL_VERSION_DIRENT_TYPE) de |= IFTODT((zp)->z_phys->zp_mode) << 60; return (de); } /* * Link zp into dl. Can only fail if zp has been unlinked. */ int zfs_link_create(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag) { znode_t *dzp = dl->dl_dzp; vnode_t *vp = ZTOV(zp); uint64_t value; int zp_is_dir = (vp->v_type == VDIR); int error; dmu_buf_will_dirty(zp->z_dbuf, tx); mutex_enter(&zp->z_lock); if (!(flag & ZRENAMING)) { if (zp->z_unlinked) { /* no new links to unlinked zp */ ASSERT(!(flag & (ZNEW | ZEXISTS))); mutex_exit(&zp->z_lock); return (ENOENT); } zp->z_phys->zp_links++; } zp->z_phys->zp_parent = dzp->z_id; /* dzp is now zp's parent */ if (!(flag & ZNEW)) zfs_time_stamper_locked(zp, STATE_CHANGED, tx); mutex_exit(&zp->z_lock); dmu_buf_will_dirty(dzp->z_dbuf, tx); mutex_enter(&dzp->z_lock); dzp->z_phys->zp_size++; /* one dirent added */ dzp->z_phys->zp_links += zp_is_dir; /* ".." link from zp */ zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx); mutex_exit(&dzp->z_lock); value = zfs_dirent(zp); error = zap_add(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name, 8, 1, &value, tx); ASSERT(error == 0); dnlc_update(ZTOV(dzp), dl->dl_name, vp); return (0); } /* * Unlink zp from dl, and mark zp for deletion if this was the last link. * Can fail if zp is a mount point (EBUSY) or a non-empty directory (EEXIST). * If 'unlinkedp' is NULL, we put unlinked znodes on the unlinked list. * If it's non-NULL, we use it to indicate whether the znode needs deletion, * and it's the caller's job to do it. */ int zfs_link_destroy(zfs_dirlock_t *dl, znode_t *zp, dmu_tx_t *tx, int flag, boolean_t *unlinkedp) { znode_t *dzp = dl->dl_dzp; vnode_t *vp = ZTOV(zp); int zp_is_dir = (vp->v_type == VDIR); boolean_t unlinked = B_FALSE; int error; dnlc_remove(ZTOV(dzp), dl->dl_name); if (!(flag & ZRENAMING)) { dmu_buf_will_dirty(zp->z_dbuf, tx); if (vn_vfswlock(vp)) /* prevent new mounts on zp */ return (EBUSY); if (vn_ismntpt(vp)) { /* don't remove mount point */ vn_vfsunlock(vp); return (EBUSY); } mutex_enter(&zp->z_lock); if (zp_is_dir && !zfs_dirempty(zp)) { /* dir not empty */ mutex_exit(&zp->z_lock); vn_vfsunlock(vp); return (EEXIST); } if (zp->z_phys->zp_links <= zp_is_dir) { zfs_panic_recover("zfs: link count on %s is %u, " "should be at least %u", zp->z_vnode->v_path ? zp->z_vnode->v_path : "", (int)zp->z_phys->zp_links, zp_is_dir + 1); zp->z_phys->zp_links = zp_is_dir + 1; } if (--zp->z_phys->zp_links == zp_is_dir) { zp->z_unlinked = B_TRUE; zp->z_phys->zp_links = 0; unlinked = B_TRUE; } else { zfs_time_stamper_locked(zp, STATE_CHANGED, tx); } mutex_exit(&zp->z_lock); vn_vfsunlock(vp); } dmu_buf_will_dirty(dzp->z_dbuf, tx); mutex_enter(&dzp->z_lock); dzp->z_phys->zp_size--; /* one dirent removed */ dzp->z_phys->zp_links -= zp_is_dir; /* ".." link from zp */ zfs_time_stamper_locked(dzp, CONTENT_MODIFIED, tx); mutex_exit(&dzp->z_lock); if (zp->z_zfsvfs->z_norm) { if (((zp->z_zfsvfs->z_case == ZFS_CASE_INSENSITIVE) && (flag & ZCIEXACT)) || ((zp->z_zfsvfs->z_case == ZFS_CASE_MIXED) && !(flag & ZCILOOK))) error = zap_remove_norm(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name, MT_EXACT, tx); else error = zap_remove_norm(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name, MT_FIRST, tx); } else { error = zap_remove(zp->z_zfsvfs->z_os, dzp->z_id, dl->dl_name, tx); } ASSERT(error == 0); if (unlinkedp != NULL) *unlinkedp = unlinked; else if (unlinked) zfs_unlinked_add(zp, tx); return (0); } /* * Indicate whether the directory is empty. Works with or without z_lock * held, but can only be consider a hint in the latter case. Returns true * if only "." and ".." remain and there's no work in progress. */ boolean_t zfs_dirempty(znode_t *dzp) { return (dzp->z_phys->zp_size == 2 && dzp->z_dirlocks == 0); } int zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr) { zfsvfs_t *zfsvfs = zp->z_zfsvfs; znode_t *xzp; dmu_tx_t *tx; int error; zfs_fuid_info_t *fuidp = NULL; *xvpp = NULL; if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr)) return (error); tx = dmu_tx_create(zfsvfs->z_os); dmu_tx_hold_bonus(tx, zp->z_id); dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL); if (IS_EPHEMERAL(crgetuid(cr)) || IS_EPHEMERAL(crgetgid(cr))) { if (zfsvfs->z_fuid_obj == 0) { dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, FUID_SIZE_ESTIMATE(zfsvfs)); dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL); } else { dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj); dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0, FUID_SIZE_ESTIMATE(zfsvfs)); } } error = dmu_tx_assign(tx, zfsvfs->z_assign); if (error) { if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) dmu_tx_wait(tx); dmu_tx_abort(tx); return (error); } zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, 0, NULL, &fuidp); ASSERT(xzp->z_phys->zp_parent == zp->z_id); dmu_buf_will_dirty(zp->z_dbuf, tx); zp->z_phys->zp_xattr = xzp->z_id; (void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp, xzp, "", NULL, fuidp, vap); if (fuidp) zfs_fuid_info_free(fuidp); dmu_tx_commit(tx); *xvpp = ZTOV(xzp); return (0); } /* * Return a znode for the extended attribute directory for zp. * ** If the directory does not already exist, it is created ** * * IN: zp - znode to obtain attribute directory from * cr - credentials of caller * flags - flags from the VOP_LOOKUP call * * OUT: xzpp - pointer to extended attribute znode * * RETURN: 0 on success * error number on failure */ int zfs_get_xattrdir(znode_t *zp, vnode_t **xvpp, cred_t *cr, int flags) { zfsvfs_t *zfsvfs = zp->z_zfsvfs; znode_t *xzp; zfs_dirlock_t *dl; vattr_t va; int error; top: error = zfs_dirent_lock(&dl, zp, "", &xzp, ZXATTR, NULL, NULL); if (error) return (error); if (xzp != NULL) { *xvpp = ZTOV(xzp); zfs_dirent_unlock(dl); return (0); } ASSERT(zp->z_phys->zp_xattr == 0); if (!(flags & CREATE_XATTR_DIR)) { zfs_dirent_unlock(dl); return (ENOENT); } if (zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) { zfs_dirent_unlock(dl); return (EROFS); } /* * The ability to 'create' files in an attribute * directory comes from the write_xattr permission on the base file. * * The ability to 'search' an attribute directory requires * read_xattr permission on the base file. * * Once in a directory the ability to read/write attributes * is controlled by the permissions on the attribute file. */ va.va_mask = AT_TYPE | AT_MODE | AT_UID | AT_GID; va.va_type = VDIR; va.va_mode = S_IFDIR | S_ISVTX | 0777; zfs_fuid_map_ids(zp, cr, &va.va_uid, &va.va_gid); error = zfs_make_xattrdir(zp, &va, xvpp, cr); zfs_dirent_unlock(dl); if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT) { /* 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_assign >= TXG_INITIAL) /* ZIL replay */ return (0); if ((zdp->z_phys->zp_mode & S_ISVTX) == 0) return (0); downer = zfs_fuid_map_id(zfsvfs, zdp->z_phys->zp_uid, cr, ZFS_OWNER); fowner = zfs_fuid_map_id(zfsvfs, zp->z_phys->zp_uid, cr, ZFS_OWNER); if ((uid = crgetuid(cr)) == downer || uid == fowner || (ZTOV(zp)->v_type == VREG && zfs_zaccess(zp, ACE_WRITE_DATA, 0, B_FALSE, cr) == 0)) return (0); else return (secpolicy_vnode_remove(cr)); }