diff options
Diffstat (limited to 'sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c')
| -rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c | 1061 |
1 files changed, 1061 insertions, 0 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c new file mode 100644 index 0000000..d2806b9 --- /dev/null +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_znode.c @@ -0,0 +1,1061 @@ +/* + * 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 2007 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ + +#pragma ident "%Z%%M% %I% %E% SMI" + +#ifdef _KERNEL +#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/mntent.h> +#include <sys/vfs.h> +#include <sys/vnode.h> +#include <sys/file.h> +#include <sys/kmem.h> +#include <sys/cmn_err.h> +#include <sys/errno.h> +#include <sys/unistd.h> +#include <sys/atomic.h> +#include <sys/zfs_dir.h> +#include <sys/zfs_acl.h> +#include <sys/zfs_ioctl.h> +#include <sys/zfs_rlock.h> +#include <sys/fs/zfs.h> +#endif /* _KERNEL */ + +#include <sys/dmu.h> +#include <sys/refcount.h> +#include <sys/stat.h> +#include <sys/zap.h> +#include <sys/zfs_znode.h> +#include <sys/refcount.h> + +/* + * Functions needed for userland (ie: libzpool) are not put under + * #ifdef_KERNEL; the rest of the functions have dependencies + * (such as VFS logic) that will not compile easily in userland. + */ +#ifdef _KERNEL +struct kmem_cache *znode_cache = NULL; + +/*ARGSUSED*/ +static void +znode_pageout_func(dmu_buf_t *dbuf, void *user_ptr) +{ + znode_t *zp = user_ptr; + vnode_t *vp = ZTOV(zp); + + mutex_enter(&zp->z_lock); + if (vp == NULL) { + mutex_exit(&zp->z_lock); + zfs_znode_free(zp); + } else if (vp->v_count == 0) { + ZTOV(zp) = NULL; + mutex_exit(&zp->z_lock); + vhold(vp); + vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread); + vrecycle(vp, curthread); + VOP_UNLOCK(vp, 0, curthread); + vdrop(vp); + zfs_znode_free(zp); + } else { + /* signal force unmount that this znode can be freed */ + zp->z_dbuf = NULL; + mutex_exit(&zp->z_lock); + } +} + +extern struct vop_vector zfs_vnodeops; +extern struct vop_vector zfs_fifoops; + +/* + * XXX: We cannot use this function as a cache constructor, because + * there is one global cache for all file systems and we need + * to pass vfsp here, which is not possible, because argument + * 'cdrarg' is defined at kmem_cache_create() time. + */ +static int +zfs_znode_cache_constructor(void *buf, void *cdrarg, int kmflags) +{ + znode_t *zp = buf; + vfs_t *vfsp = cdrarg; + int error; + + if (cdrarg != NULL) { + error = getnewvnode("zfs", vfsp, &zfs_vnodeops, &zp->z_vnode); + ASSERT(error == 0); + zp->z_vnode->v_data = (caddr_t)zp; + vhold(zp->z_vnode); + } else { + zp->z_vnode = NULL; + } + mutex_init(&zp->z_lock, NULL, MUTEX_DEFAULT, NULL); + rw_init(&zp->z_map_lock, NULL, RW_DEFAULT, NULL); + rw_init(&zp->z_parent_lock, NULL, RW_DEFAULT, NULL); + rw_init(&zp->z_name_lock, NULL, RW_DEFAULT, NULL); + mutex_init(&zp->z_acl_lock, NULL, MUTEX_DEFAULT, NULL); + + mutex_init(&zp->z_range_lock, NULL, MUTEX_DEFAULT, NULL); + avl_create(&zp->z_range_avl, zfs_range_compare, + sizeof (rl_t), offsetof(rl_t, r_node)); + + zp->z_dbuf_held = 0; + zp->z_dirlocks = 0; + zp->z_lockf = NULL; + return (0); +} + +/*ARGSUSED*/ +static void +zfs_znode_cache_destructor(void *buf, void *cdarg) +{ + znode_t *zp = buf; + + ASSERT(zp->z_dirlocks == 0); + mutex_destroy(&zp->z_lock); + rw_destroy(&zp->z_map_lock); + rw_destroy(&zp->z_parent_lock); + rw_destroy(&zp->z_name_lock); + mutex_destroy(&zp->z_acl_lock); + mutex_destroy(&zp->z_range_lock); + avl_destroy(&zp->z_range_avl); + + ASSERT(zp->z_dbuf_held == 0); +} + +void +zfs_znode_init(void) +{ + /* + * Initialize zcache + */ + ASSERT(znode_cache == NULL); + znode_cache = kmem_cache_create("zfs_znode_cache", + sizeof (znode_t), 0, /* zfs_znode_cache_constructor */ NULL, + zfs_znode_cache_destructor, NULL, NULL, NULL, 0); +} + +void +zfs_znode_fini(void) +{ + /* + * Cleanup zcache + */ + if (znode_cache) + kmem_cache_destroy(znode_cache); + znode_cache = NULL; +} + +/* + * zfs_init_fs - Initialize the zfsvfs struct and the file system + * incore "master" object. Verify version compatibility. + */ +int +zfs_init_fs(zfsvfs_t *zfsvfs, znode_t **zpp, cred_t *cr) +{ + objset_t *os = zfsvfs->z_os; + uint64_t version = ZPL_VERSION; + int i, error; + dmu_object_info_t doi; + uint64_t fsid_guid; + + *zpp = NULL; + + /* + * XXX - hack to auto-create the pool root filesystem at + * the first attempted mount. + */ + if (dmu_object_info(os, MASTER_NODE_OBJ, &doi) == ENOENT) { + dmu_tx_t *tx = dmu_tx_create(os); + + dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, TRUE, NULL); /* master */ + dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, TRUE, NULL); /* del queue */ + dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT); /* root node */ + error = dmu_tx_assign(tx, TXG_WAIT); + ASSERT3U(error, ==, 0); + zfs_create_fs(os, cr, tx); + dmu_tx_commit(tx); + } + + error = zap_lookup(os, MASTER_NODE_OBJ, ZPL_VERSION_OBJ, 8, 1, + &version); + if (error) { + return (error); + } else if (version != ZPL_VERSION) { + (void) printf("Mismatched versions: File system " + "is version %lld on-disk format, which is " + "incompatible with this software version %lld!", + (u_longlong_t)version, ZPL_VERSION); + return (ENOTSUP); + } + + /* + * The fsid is 64 bits, composed of an 8-bit fs type, which + * separates our fsid from any other filesystem types, and a + * 56-bit objset unique ID. The objset unique ID is unique to + * all objsets open on this system, provided by unique_create(). + * The 8-bit fs type must be put in the low bits of fsid[1] + * because that's where other Solaris filesystems put it. + */ + fsid_guid = dmu_objset_fsid_guid(os); + ASSERT((fsid_guid & ~((1ULL<<56)-1)) == 0); + zfsvfs->z_vfs->vfs_fsid.val[0] = fsid_guid; + zfsvfs->z_vfs->vfs_fsid.val[1] = ((fsid_guid>>32) << 8) | + zfsvfs->z_vfs->mnt_vfc->vfc_typenum & 0xFF; + + error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_ROOT_OBJ, 8, 1, + &zfsvfs->z_root); + if (error) + return (error); + ASSERT(zfsvfs->z_root != 0); + + /* + * Create the per mount vop tables. + */ + + /* + * Initialize zget mutex's + */ + for (i = 0; i != ZFS_OBJ_MTX_SZ; i++) + mutex_init(&zfsvfs->z_hold_mtx[i], NULL, MUTEX_DEFAULT, NULL); + + error = zfs_zget(zfsvfs, zfsvfs->z_root, zpp); + if (error) + return (error); + ASSERT3U((*zpp)->z_id, ==, zfsvfs->z_root); + + error = zap_lookup(os, MASTER_NODE_OBJ, ZFS_UNLINKED_SET, 8, 1, + &zfsvfs->z_unlinkedobj); + if (error) + return (error); + + return (0); +} + +/* + * define a couple of values we need available + * for both 64 and 32 bit environments. + */ +#ifndef NBITSMINOR64 +#define NBITSMINOR64 32 +#endif +#ifndef MAXMAJ64 +#define MAXMAJ64 0xffffffffUL +#endif +#ifndef MAXMIN64 +#define MAXMIN64 0xffffffffUL +#endif + +/* + * Create special expldev for ZFS private use. + * Can't use standard expldev since it doesn't do + * what we want. The standard expldev() takes a + * dev32_t in LP64 and expands it to a long dev_t. + * We need an interface that takes a dev32_t in ILP32 + * and expands it to a long dev_t. + */ +static uint64_t +zfs_expldev(dev_t dev) +{ + return ((uint64_t)0); +} +/* + * Special cmpldev for ZFS private use. + * Can't use standard cmpldev since it takes + * a long dev_t and compresses it to dev32_t in + * LP64. We need to do a compaction of a long dev_t + * to a dev32_t in ILP32. + */ +dev_t +zfs_cmpldev(uint64_t dev) +{ + return ((dev_t)0); +} + +/* + * Construct a new znode/vnode and intialize. + * + * This does not do a call to dmu_set_user() that is + * up to the caller to do, in case you don't want to + * return the znode + */ +static znode_t * +zfs_znode_alloc(zfsvfs_t *zfsvfs, dmu_buf_t *db, uint64_t obj_num, int blksz) +{ + znode_t *zp; + vnode_t *vp; + int error; + + zp = kmem_cache_alloc(znode_cache, KM_SLEEP); + zfs_znode_cache_constructor(zp, zfsvfs->z_vfs, 0); + + ASSERT(zp->z_dirlocks == NULL); + + zp->z_phys = db->db_data; + zp->z_zfsvfs = zfsvfs; + zp->z_unlinked = 0; + zp->z_atime_dirty = 0; + zp->z_dbuf_held = 0; + zp->z_mapcnt = 0; + zp->z_last_itx = 0; + zp->z_dbuf = db; + zp->z_id = obj_num; + zp->z_blksz = blksz; + zp->z_seq = 0x7A4653; + zp->z_sync_cnt = 0; + + mutex_enter(&zfsvfs->z_znodes_lock); + list_insert_tail(&zfsvfs->z_all_znodes, zp); + mutex_exit(&zfsvfs->z_znodes_lock); + + vp = ZTOV(zp); + if (vp == NULL) + return (zp); + + error = insmntque(vp, zfsvfs->z_vfs); + KASSERT(error == 0, ("insmntque() failed: error %d", error)); + + vp->v_type = IFTOVT((mode_t)zp->z_phys->zp_mode); + switch (vp->v_type) { + case VDIR: + zp->z_zn_prefetch = B_TRUE; /* z_prefetch default is enabled */ + break; + case VFIFO: + vp->v_op = &zfs_fifoops; + break; + } + + return (zp); +} + +static void +zfs_znode_dmu_init(znode_t *zp) +{ + znode_t *nzp; + zfsvfs_t *zfsvfs = zp->z_zfsvfs; + dmu_buf_t *db = zp->z_dbuf; + + mutex_enter(&zp->z_lock); + + nzp = dmu_buf_set_user(db, zp, &zp->z_phys, znode_pageout_func); + + /* + * there should be no + * concurrent zgets on this object. + */ + ASSERT3P(nzp, ==, NULL); + + /* + * Slap on VROOT if we are the root znode + */ + if (zp->z_id == zfsvfs->z_root) { + ZTOV(zp)->v_flag |= VROOT; + } + + ASSERT(zp->z_dbuf_held == 0); + zp->z_dbuf_held = 1; + VFS_HOLD(zfsvfs->z_vfs); + mutex_exit(&zp->z_lock); +} + +/* + * Create a new DMU object to hold a zfs znode. + * + * IN: dzp - parent directory for new znode + * vap - file attributes for new znode + * tx - dmu transaction id for zap operations + * cr - credentials of caller + * flag - flags: + * IS_ROOT_NODE - new object will be root + * IS_XATTR - new object is an attribute + * IS_REPLAY - intent log replay + * + * OUT: oid - ID of created object + * + */ +void +zfs_mknode(znode_t *dzp, vattr_t *vap, uint64_t *oid, dmu_tx_t *tx, cred_t *cr, + uint_t flag, znode_t **zpp, int bonuslen) +{ + dmu_buf_t *dbp; + znode_phys_t *pzp; + znode_t *zp; + zfsvfs_t *zfsvfs = dzp->z_zfsvfs; + timestruc_t now; + uint64_t gen; + int err; + + ASSERT(vap && (vap->va_mask & (AT_TYPE|AT_MODE)) == (AT_TYPE|AT_MODE)); + + if (zfsvfs->z_assign >= TXG_INITIAL) { /* ZIL replay */ + *oid = vap->va_nodeid; + flag |= IS_REPLAY; + now = vap->va_ctime; /* see zfs_replay_create() */ + gen = vap->va_nblocks; /* ditto */ + } else { + *oid = 0; + gethrestime(&now); + gen = dmu_tx_get_txg(tx); + } + + /* + * Create a new DMU object. + */ + /* + * There's currently no mechanism for pre-reading the blocks that will + * be to needed allocate a new object, so we accept the small chance + * that there will be an i/o error and we will fail one of the + * assertions below. + */ + if (vap->va_type == VDIR) { + if (flag & IS_REPLAY) { + err = zap_create_claim(zfsvfs->z_os, *oid, + DMU_OT_DIRECTORY_CONTENTS, + DMU_OT_ZNODE, sizeof (znode_phys_t) + bonuslen, tx); + ASSERT3U(err, ==, 0); + } else { + *oid = zap_create(zfsvfs->z_os, + DMU_OT_DIRECTORY_CONTENTS, + DMU_OT_ZNODE, sizeof (znode_phys_t) + bonuslen, tx); + } + } else { + if (flag & IS_REPLAY) { + err = dmu_object_claim(zfsvfs->z_os, *oid, + DMU_OT_PLAIN_FILE_CONTENTS, 0, + DMU_OT_ZNODE, sizeof (znode_phys_t) + bonuslen, tx); + ASSERT3U(err, ==, 0); + } else { + *oid = dmu_object_alloc(zfsvfs->z_os, + DMU_OT_PLAIN_FILE_CONTENTS, 0, + DMU_OT_ZNODE, sizeof (znode_phys_t) + bonuslen, tx); + } + } + VERIFY(0 == dmu_bonus_hold(zfsvfs->z_os, *oid, NULL, &dbp)); + dmu_buf_will_dirty(dbp, tx); + + /* + * Initialize the znode physical data to zero. + */ + ASSERT(dbp->db_size >= sizeof (znode_phys_t)); + bzero(dbp->db_data, dbp->db_size); + pzp = dbp->db_data; + + /* + * If this is the root, fix up the half-initialized parent pointer + * to reference the just-allocated physical data area. + */ + if (flag & IS_ROOT_NODE) { + dzp->z_phys = pzp; + dzp->z_id = *oid; + } + + /* + * If parent is an xattr, so am I. + */ + if (dzp->z_phys->zp_flags & ZFS_XATTR) + flag |= IS_XATTR; + + if (vap->va_type == VBLK || vap->va_type == VCHR) { + pzp->zp_rdev = zfs_expldev(vap->va_rdev); + } + + if (vap->va_type == VDIR) { + pzp->zp_size = 2; /* contents ("." and "..") */ + pzp->zp_links = (flag & (IS_ROOT_NODE | IS_XATTR)) ? 2 : 1; + } + + pzp->zp_parent = dzp->z_id; + if (flag & IS_XATTR) + pzp->zp_flags |= ZFS_XATTR; + + pzp->zp_gen = gen; + + ZFS_TIME_ENCODE(&now, pzp->zp_crtime); + ZFS_TIME_ENCODE(&now, pzp->zp_ctime); + + if (vap->va_mask & AT_ATIME) { + ZFS_TIME_ENCODE(&vap->va_atime, pzp->zp_atime); + } else { + ZFS_TIME_ENCODE(&now, pzp->zp_atime); + } + + if (vap->va_mask & AT_MTIME) { + ZFS_TIME_ENCODE(&vap->va_mtime, pzp->zp_mtime); + } else { + ZFS_TIME_ENCODE(&now, pzp->zp_mtime); + } + + pzp->zp_mode = MAKEIMODE(vap->va_type, vap->va_mode); + zp = zfs_znode_alloc(zfsvfs, dbp, *oid, 0); + + zfs_perm_init(zp, dzp, flag, vap, tx, cr); + + if (zpp) { + kmutex_t *hash_mtx = ZFS_OBJ_MUTEX(zp); + + mutex_enter(hash_mtx); + zfs_znode_dmu_init(zp); + mutex_exit(hash_mtx); + + *zpp = zp; + } else { + if (ZTOV(zp) != NULL) + ZTOV(zp)->v_count = 0; + dmu_buf_rele(dbp, NULL); + zfs_znode_free(zp); + } +} + +int +zfs_zget(zfsvfs_t *zfsvfs, uint64_t obj_num, znode_t **zpp) +{ + dmu_object_info_t doi; + dmu_buf_t *db; + znode_t *zp; + vnode_t *vp; + int err; + + *zpp = NULL; + + ZFS_OBJ_HOLD_ENTER(zfsvfs, obj_num); + + err = dmu_bonus_hold(zfsvfs->z_os, obj_num, NULL, &db); + if (err) { + ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num); + return (err); + } + + dmu_object_info_from_db(db, &doi); + if (doi.doi_bonus_type != DMU_OT_ZNODE || + doi.doi_bonus_size < sizeof (znode_phys_t)) { + dmu_buf_rele(db, NULL); + ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num); + return (EINVAL); + } + + ASSERT(db->db_object == obj_num); + ASSERT(db->db_offset == -1); + ASSERT(db->db_data != NULL); + + zp = dmu_buf_get_user(db); + + if (zp != NULL) { + mutex_enter(&zp->z_lock); + + ASSERT3U(zp->z_id, ==, obj_num); + if (zp->z_unlinked) { + dmu_buf_rele(db, NULL); + mutex_exit(&zp->z_lock); + ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num); + return (ENOENT); + } else if (zp->z_dbuf_held) { + dmu_buf_rele(db, NULL); + } else { + zp->z_dbuf_held = 1; + VFS_HOLD(zfsvfs->z_vfs); + } + + if (ZTOV(zp) != NULL) + VN_HOLD(ZTOV(zp)); + else { + err = getnewvnode("zfs", zfsvfs->z_vfs, &zfs_vnodeops, + &zp->z_vnode); + ASSERT(err == 0); + vp = ZTOV(zp); + vp->v_data = (caddr_t)zp; + vhold(vp); + vp->v_type = IFTOVT((mode_t)zp->z_phys->zp_mode); + if (vp->v_type == VDIR) + zp->z_zn_prefetch = B_TRUE; /* z_prefetch default is enabled */ + err = insmntque(vp, zfsvfs->z_vfs); + KASSERT(err == 0, ("insmntque() failed: error %d", err)); + } + mutex_exit(&zp->z_lock); + ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num); + *zpp = zp; + return (0); + } + + /* + * Not found create new znode/vnode + */ + zp = zfs_znode_alloc(zfsvfs, db, obj_num, doi.doi_data_block_size); + ASSERT3U(zp->z_id, ==, obj_num); + zfs_znode_dmu_init(zp); + ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num); + *zpp = zp; + return (0); +} + +void +zfs_znode_delete(znode_t *zp, dmu_tx_t *tx) +{ + zfsvfs_t *zfsvfs = zp->z_zfsvfs; + int error; + + ZFS_OBJ_HOLD_ENTER(zfsvfs, zp->z_id); + if (zp->z_phys->zp_acl.z_acl_extern_obj) { + error = dmu_object_free(zfsvfs->z_os, + zp->z_phys->zp_acl.z_acl_extern_obj, tx); + ASSERT3U(error, ==, 0); + } + error = dmu_object_free(zfsvfs->z_os, zp->z_id, tx); + ASSERT3U(error, ==, 0); + zp->z_dbuf_held = 0; + ZFS_OBJ_HOLD_EXIT(zfsvfs, zp->z_id); + dmu_buf_rele(zp->z_dbuf, NULL); +} + +void +zfs_zinactive(znode_t *zp) +{ + vnode_t *vp = ZTOV(zp); + zfsvfs_t *zfsvfs = zp->z_zfsvfs; + uint64_t z_id = zp->z_id; + + ASSERT(zp->z_dbuf_held && zp->z_phys); + + /* + * Don't allow a zfs_zget() while were trying to release this znode + */ + ZFS_OBJ_HOLD_ENTER(zfsvfs, z_id); + + mutex_enter(&zp->z_lock); + VI_LOCK(vp); + if (vp->v_count > 0) { + /* + * If the hold count is greater than zero, somebody has + * obtained a new reference on this znode while we were + * processing it here, so we are done. + */ + VI_UNLOCK(vp); + mutex_exit(&zp->z_lock); + ZFS_OBJ_HOLD_EXIT(zfsvfs, z_id); + return; + } + VI_UNLOCK(vp); + + /* + * If this was the last reference to a file with no links, + * remove the file from the file system. + */ + if (zp->z_unlinked) { + ZTOV(zp) = NULL; + mutex_exit(&zp->z_lock); + ZFS_OBJ_HOLD_EXIT(zfsvfs, z_id); + ASSERT(vp->v_count == 0); + vrecycle(vp, curthread); + zfs_rmnode(zp); + VFS_RELE(zfsvfs->z_vfs); + return; + } + ASSERT(zp->z_phys); + ASSERT(zp->z_dbuf_held); + + zp->z_dbuf_held = 0; + mutex_exit(&zp->z_lock); + dmu_buf_rele(zp->z_dbuf, NULL); + ZFS_OBJ_HOLD_EXIT(zfsvfs, z_id); + VFS_RELE(zfsvfs->z_vfs); +} + +/* + * FreeBSD: Should be called from ->vop_reclaim(). + */ +void +zfs_znode_free(znode_t *zp) +{ + zfsvfs_t *zfsvfs = zp->z_zfsvfs; + + mutex_enter(&zfsvfs->z_znodes_lock); + list_remove(&zfsvfs->z_all_znodes, zp); + mutex_exit(&zfsvfs->z_znodes_lock); + + kmem_cache_free(znode_cache, zp); +} + +void +zfs_time_stamper_locked(znode_t *zp, uint_t flag, dmu_tx_t *tx) +{ + timestruc_t now; + + ASSERT(MUTEX_HELD(&zp->z_lock)); + + gethrestime(&now); + + if (tx) { + dmu_buf_will_dirty(zp->z_dbuf, tx); + zp->z_atime_dirty = 0; + zp->z_seq++; + } else { + zp->z_atime_dirty = 1; + } + + if (flag & AT_ATIME) + ZFS_TIME_ENCODE(&now, zp->z_phys->zp_atime); + + if (flag & AT_MTIME) + ZFS_TIME_ENCODE(&now, zp->z_phys->zp_mtime); + + if (flag & AT_CTIME) + ZFS_TIME_ENCODE(&now, zp->z_phys->zp_ctime); +} + +/* + * Update the requested znode timestamps with the current time. + * If we are in a transaction, then go ahead and mark the znode + * dirty in the transaction so the timestamps will go to disk. + * Otherwise, we will get pushed next time the znode is updated + * in a transaction, or when this znode eventually goes inactive. + * + * Why is this OK? + * 1 - Only the ACCESS time is ever updated outside of a transaction. + * 2 - Multiple consecutive updates will be collapsed into a single + * znode update by the transaction grouping semantics of the DMU. + */ +void +zfs_time_stamper(znode_t *zp, uint_t flag, dmu_tx_t *tx) +{ + mutex_enter(&zp->z_lock); + zfs_time_stamper_locked(zp, flag, tx); + mutex_exit(&zp->z_lock); +} + +/* + * Grow the block size for a file. + * + * IN: zp - znode of file to free data in. + * size - requested block size + * tx - open transaction. + * + * NOTE: this function assumes that the znode is write locked. + */ +void +zfs_grow_blocksize(znode_t *zp, uint64_t size, dmu_tx_t *tx) +{ + int error; + u_longlong_t dummy; + + if (size <= zp->z_blksz) + return; + /* + * If the file size is already greater than the current blocksize, + * we will not grow. If there is more than one block in a file, + * the blocksize cannot change. + */ + if (zp->z_blksz && zp->z_phys->zp_size > zp->z_blksz) + return; + + error = dmu_object_set_blocksize(zp->z_zfsvfs->z_os, zp->z_id, + size, 0, tx); + if (error == ENOTSUP) + return; + ASSERT3U(error, ==, 0); + + /* What blocksize did we actually get? */ + dmu_object_size_from_db(zp->z_dbuf, &zp->z_blksz, &dummy); +} + +/* + * Free space in a file. + * + * IN: zp - znode of file to free data in. + * off - start of section to free. + * len - length of section to free (0 => to EOF). + * flag - current file open mode flags. + * + * RETURN: 0 if success + * error code if failure + */ +int +zfs_freesp(znode_t *zp, uint64_t off, uint64_t len, int flag, boolean_t log) +{ + vnode_t *vp = ZTOV(zp); + dmu_tx_t *tx; + zfsvfs_t *zfsvfs = zp->z_zfsvfs; + zilog_t *zilog = zfsvfs->z_log; + rl_t *rl; + uint64_t end = off + len; + uint64_t size, new_blksz; + int error; + + if (ZTOV(zp)->v_type == VFIFO) + return (0); + + /* + * If we will change zp_size then lock the whole file, + * otherwise just lock the range being freed. + */ + if (len == 0 || off + len > zp->z_phys->zp_size) { + rl = zfs_range_lock(zp, 0, UINT64_MAX, RL_WRITER); + } else { + rl = zfs_range_lock(zp, off, len, RL_WRITER); + /* recheck, in case zp_size changed */ + if (off + len > zp->z_phys->zp_size) { + /* lost race: file size changed, lock whole file */ + zfs_range_unlock(rl); + rl = zfs_range_lock(zp, 0, UINT64_MAX, RL_WRITER); + } + } + + /* + * Nothing to do if file already at desired length. + */ + size = zp->z_phys->zp_size; + if (len == 0 && size == off) { + zfs_range_unlock(rl); + return (0); + } + + tx = dmu_tx_create(zfsvfs->z_os); + dmu_tx_hold_bonus(tx, zp->z_id); + new_blksz = 0; + if (end > size && + (!ISP2(zp->z_blksz) || zp->z_blksz < zfsvfs->z_max_blksz)) { + /* + * We are growing the file past the current block size. + */ + if (zp->z_blksz > zp->z_zfsvfs->z_max_blksz) { + ASSERT(!ISP2(zp->z_blksz)); + new_blksz = MIN(end, SPA_MAXBLOCKSIZE); + } else { + new_blksz = MIN(end, zp->z_zfsvfs->z_max_blksz); + } + dmu_tx_hold_write(tx, zp->z_id, 0, MIN(end, new_blksz)); + } else if (off < size) { + /* + * If len == 0, we are truncating the file. + */ + dmu_tx_hold_free(tx, zp->z_id, off, len ? len : DMU_OBJECT_END); + } + + 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); + zfs_range_unlock(rl); + return (error); + } + + if (new_blksz) + zfs_grow_blocksize(zp, new_blksz, tx); + + if (end > size || len == 0) + zp->z_phys->zp_size = end; + + if (off < size) { + objset_t *os = zfsvfs->z_os; + uint64_t rlen = len; + + if (len == 0) + rlen = -1; + else if (end > size) + rlen = size - off; + VERIFY(0 == dmu_free_range(os, zp->z_id, off, rlen, tx)); + } + + if (log) { + zfs_time_stamper(zp, CONTENT_MODIFIED, tx); + zfs_log_truncate(zilog, tx, TX_TRUNCATE, zp, off, len); + } + + zfs_range_unlock(rl); + + dmu_tx_commit(tx); + + /* + * Clear any mapped pages in the truncated region. This has to + * happen outside of the transaction to avoid the possibility of + * a deadlock with someone trying to push a page that we are + * about to invalidate. + */ + rw_enter(&zp->z_map_lock, RW_WRITER); + if (end > size) + vnode_pager_setsize(vp, end); + else if (len == 0) { +#if 0 + error = vtruncbuf(vp, curthread->td_ucred, curthread, end, PAGE_SIZE); +#else + error = vinvalbuf(vp, V_SAVE, curthread, 0, 0); + vnode_pager_setsize(vp, end); +#endif + } + rw_exit(&zp->z_map_lock); + + return (0); +} + +void +zfs_create_fs(objset_t *os, cred_t *cr, dmu_tx_t *tx) +{ + zfsvfs_t zfsvfs; + uint64_t moid, doid, roid = 0; + uint64_t version = ZPL_VERSION; + int error; + znode_t *rootzp = NULL; + vattr_t vattr; + + /* + * First attempt to create master node. + */ + /* + * In an empty objset, there are no blocks to read and thus + * there can be no i/o errors (which we assert below). + */ + moid = MASTER_NODE_OBJ; + error = zap_create_claim(os, moid, DMU_OT_MASTER_NODE, + DMU_OT_NONE, 0, tx); + ASSERT(error == 0); + + /* + * Set starting attributes. + */ + + error = zap_update(os, moid, ZPL_VERSION_OBJ, 8, 1, &version, tx); + ASSERT(error == 0); + + /* + * Create a delete queue. + */ + doid = zap_create(os, DMU_OT_UNLINKED_SET, DMU_OT_NONE, 0, tx); + + error = zap_add(os, moid, ZFS_UNLINKED_SET, 8, 1, &doid, tx); + ASSERT(error == 0); + + /* + * Create root znode. Create minimal znode/vnode/zfsvfs + * to allow zfs_mknode to work. + */ + vattr.va_mask = AT_MODE|AT_UID|AT_GID|AT_TYPE; + vattr.va_type = VDIR; + vattr.va_mode = S_IFDIR|0755; + vattr.va_uid = UID_ROOT; + vattr.va_gid = GID_WHEEL; + + rootzp = kmem_cache_alloc(znode_cache, KM_SLEEP); + zfs_znode_cache_constructor(rootzp, NULL, 0); + rootzp->z_zfsvfs = &zfsvfs; + rootzp->z_unlinked = 0; + rootzp->z_atime_dirty = 0; + rootzp->z_dbuf_held = 0; + + bzero(&zfsvfs, sizeof (zfsvfs_t)); + + zfsvfs.z_os = os; + zfsvfs.z_assign = TXG_NOWAIT; + zfsvfs.z_parent = &zfsvfs; + + mutex_init(&zfsvfs.z_znodes_lock, NULL, MUTEX_DEFAULT, NULL); + list_create(&zfsvfs.z_all_znodes, sizeof (znode_t), + offsetof(znode_t, z_link_node)); + + zfs_mknode(rootzp, &vattr, &roid, tx, cr, IS_ROOT_NODE, NULL, 0); + ASSERT3U(rootzp->z_id, ==, roid); + error = zap_add(os, moid, ZFS_ROOT_OBJ, 8, 1, &roid, tx); + ASSERT(error == 0); + + kmem_cache_free(znode_cache, rootzp); +} +#endif /* _KERNEL */ + +/* + * Given an object number, return its parent object number and whether + * or not the object is an extended attribute directory. + */ +static int +zfs_obj_to_pobj(objset_t *osp, uint64_t obj, uint64_t *pobjp, int *is_xattrdir) +{ + dmu_buf_t *db; + dmu_object_info_t doi; + znode_phys_t *zp; + int error; + + if ((error = dmu_bonus_hold(osp, obj, FTAG, &db)) != 0) + return (error); + + dmu_object_info_from_db(db, &doi); + if (doi.doi_bonus_type != DMU_OT_ZNODE || + doi.doi_bonus_size < sizeof (znode_phys_t)) { + dmu_buf_rele(db, FTAG); + return (EINVAL); + } + + zp = db->db_data; + *pobjp = zp->zp_parent; + *is_xattrdir = ((zp->zp_flags & ZFS_XATTR) != 0) && + S_ISDIR(zp->zp_mode); + dmu_buf_rele(db, FTAG); + + return (0); +} + +int +zfs_obj_to_path(objset_t *osp, uint64_t obj, char *buf, int len) +{ + char *path = buf + len - 1; + int error; + + *path = '\0'; + + for (;;) { + uint64_t pobj; + char component[MAXNAMELEN + 2]; + size_t complen; + int is_xattrdir; + + if ((error = zfs_obj_to_pobj(osp, obj, &pobj, + &is_xattrdir)) != 0) + break; + + if (pobj == obj) { + if (path[0] != '/') + *--path = '/'; + break; + } + + component[0] = '/'; + if (is_xattrdir) { + (void) sprintf(component + 1, "<xattrdir>"); + } else { + error = zap_value_search(osp, pobj, obj, component + 1); + if (error != 0) + break; + } + + complen = strlen(component); + path -= complen; + ASSERT(path >= buf); + bcopy(component, path, complen); + obj = pobj; + } + + if (error == 0) + (void) memmove(buf, path, buf + len - path); + return (error); +} |
