diff options
author | avg <avg@FreeBSD.org> | 2017-03-23 08:16:29 +0000 |
---|---|---|
committer | avg <avg@FreeBSD.org> | 2017-03-23 08:16:29 +0000 |
commit | fa225268a01ab93c33cbfd59dbae30840795e930 (patch) | |
tree | 0faeff73e4f659bac9ab0c1b903929473fa31dda /sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c | |
parent | 081727b69c5da8348dfb201c7bc8340360368fbe (diff) | |
download | FreeBSD-src-fa225268a01ab93c33cbfd59dbae30840795e930.zip FreeBSD-src-fa225268a01ab93c33cbfd59dbae30840795e930.tar.gz |
MFC r314048,r314194: reimplement zfsctl (.zfs) support
Diffstat (limited to 'sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c')
-rw-r--r-- | sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c | 1931 |
1 files changed, 699 insertions, 1232 deletions
diff --git a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c index 9ac5fc2..7acacc5 100644 --- a/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c +++ b/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/zfs_ctldir.c @@ -70,136 +70,249 @@ #include <sys/zfs_ioctl.h> #include <sys/zfs_vfsops.h> #include <sys/namei.h> -#include <sys/gfs.h> #include <sys/stat.h> #include <sys/dmu.h> +#include <sys/dsl_dataset.h> #include <sys/dsl_destroy.h> #include <sys/dsl_deleg.h> #include <sys/mount.h> -#include <sys/sunddi.h> +#include <sys/zap.h> #include "zfs_namecheck.h" -typedef struct zfsctl_node { - gfs_dir_t zc_gfs_private; - uint64_t zc_id; - timestruc_t zc_cmtime; /* ctime and mtime, always the same */ -} zfsctl_node_t; +/* + * "Synthetic" filesystem implementation. + */ + +/* + * Assert that A implies B. + */ +#define KASSERT_IMPLY(A, B, msg) KASSERT(!(A) || (B), (msg)); -typedef struct zfsctl_snapdir { - zfsctl_node_t sd_node; - kmutex_t sd_lock; - avl_tree_t sd_snaps; -} zfsctl_snapdir_t; +static MALLOC_DEFINE(M_SFSNODES, "sfs_nodes", "synthetic-fs nodes"); -typedef struct { - char *se_name; - vnode_t *se_root; - avl_node_t se_node; -} zfs_snapentry_t; +typedef struct sfs_node { + char sn_name[ZFS_MAX_DATASET_NAME_LEN]; + uint64_t sn_parent_id; + uint64_t sn_id; +} sfs_node_t; +/* + * Check the parent's ID as well as the node's to account for a chance + * that IDs originating from different domains (snapshot IDs, artifical + * IDs, znode IDs) may clash. + */ static int -snapentry_compare(const void *a, const void *b) +sfs_compare_ids(struct vnode *vp, void *arg) { - const zfs_snapentry_t *sa = a; - const zfs_snapentry_t *sb = b; - int ret = strcmp(sa->se_name, sb->se_name); - - if (ret < 0) - return (-1); - else if (ret > 0) - return (1); - else - return (0); + sfs_node_t *n1 = vp->v_data; + sfs_node_t *n2 = arg; + bool equal; + + equal = n1->sn_id == n2->sn_id && + n1->sn_parent_id == n2->sn_parent_id; + + /* Zero means equality. */ + return (!equal); } -#ifdef illumos -vnodeops_t *zfsctl_ops_root; -vnodeops_t *zfsctl_ops_snapdir; -vnodeops_t *zfsctl_ops_snapshot; -vnodeops_t *zfsctl_ops_shares; -vnodeops_t *zfsctl_ops_shares_dir; - -static const fs_operation_def_t zfsctl_tops_root[]; -static const fs_operation_def_t zfsctl_tops_snapdir[]; -static const fs_operation_def_t zfsctl_tops_snapshot[]; -static const fs_operation_def_t zfsctl_tops_shares[]; -#else -static struct vop_vector zfsctl_ops_root; -static struct vop_vector zfsctl_ops_snapdir; -static struct vop_vector zfsctl_ops_snapshot; -static struct vop_vector zfsctl_ops_shares; -static struct vop_vector zfsctl_ops_shares_dir; -#endif +static int +sfs_vnode_get(const struct mount *mp, int flags, uint64_t parent_id, + uint64_t id, struct vnode **vpp) +{ + sfs_node_t search; + int err; -static vnode_t *zfsctl_mknode_snapdir(vnode_t *); -static vnode_t *zfsctl_mknode_shares(vnode_t *); -static vnode_t *zfsctl_snapshot_mknode(vnode_t *, uint64_t objset); -static int zfsctl_unmount_snap(zfs_snapentry_t *, int, cred_t *); - -#ifdef illumos -static gfs_opsvec_t zfsctl_opsvec[] = { - { ".zfs", zfsctl_tops_root, &zfsctl_ops_root }, - { ".zfs/snapshot", zfsctl_tops_snapdir, &zfsctl_ops_snapdir }, - { ".zfs/snapshot/vnode", zfsctl_tops_snapshot, &zfsctl_ops_snapshot }, - { ".zfs/shares", zfsctl_tops_shares, &zfsctl_ops_shares_dir }, - { ".zfs/shares/vnode", zfsctl_tops_shares, &zfsctl_ops_shares }, - { NULL } -}; -#endif + search.sn_id = id; + search.sn_parent_id = parent_id; + err = vfs_hash_get(mp, (u_int)id, flags, curthread, vpp, + sfs_compare_ids, &search); + return (err); +} -/* - * Root directory elements. We only have two entries - * snapshot and shares. - */ -static gfs_dirent_t zfsctl_root_entries[] = { - { "snapshot", zfsctl_mknode_snapdir, GFS_CACHE_VNODE }, - { "shares", zfsctl_mknode_shares, GFS_CACHE_VNODE }, - { NULL } -}; +static int +sfs_vnode_insert(struct vnode *vp, int flags, uint64_t parent_id, + uint64_t id, struct vnode **vpp) +{ + int err; + + KASSERT(vp->v_data != NULL, ("sfs_vnode_insert with NULL v_data")); + err = vfs_hash_insert(vp, (u_int)id, flags, curthread, vpp, + sfs_compare_ids, vp->v_data); + return (err); +} + +static void +sfs_vnode_remove(struct vnode *vp) +{ + vfs_hash_remove(vp); +} + +typedef void sfs_vnode_setup_fn(vnode_t *vp, void *arg); + +static int +sfs_vgetx(struct mount *mp, int flags, uint64_t parent_id, uint64_t id, + const char *tag, struct vop_vector *vops, + sfs_vnode_setup_fn setup, void *arg, + struct vnode **vpp) +{ + struct vnode *vp; + int error; + + error = sfs_vnode_get(mp, flags, parent_id, id, vpp); + if (error != 0 || *vpp != NULL) { + KASSERT_IMPLY(error == 0, (*vpp)->v_data != NULL, + "sfs vnode with no data"); + return (error); + } + + /* Allocate a new vnode/inode. */ + error = getnewvnode(tag, mp, vops, &vp); + if (error != 0) { + *vpp = NULL; + return (error); + } + + /* + * Exclusively lock the vnode vnode while it's being constructed. + */ + lockmgr(vp->v_vnlock, LK_EXCLUSIVE, NULL); + error = insmntque(vp, mp); + if (error != 0) { + *vpp = NULL; + return (error); + } + + setup(vp, arg); + + error = sfs_vnode_insert(vp, flags, parent_id, id, vpp); + if (error != 0 || *vpp != NULL) { + KASSERT_IMPLY(error == 0, (*vpp)->v_data != NULL, + "sfs vnode with no data"); + return (error); + } + + *vpp = vp; + return (0); +} + +static void +sfs_print_node(sfs_node_t *node) +{ + printf("\tname = %s\n", node->sn_name); + printf("\tparent_id = %ju\n", (uintmax_t)node->sn_parent_id); + printf("\tid = %ju\n", (uintmax_t)node->sn_id); +} + +static sfs_node_t * +sfs_alloc_node(size_t size, const char *name, uint64_t parent_id, uint64_t id) +{ + struct sfs_node *node; + + KASSERT(strlen(name) < sizeof(node->sn_name), + ("sfs node name is too long")); + KASSERT(size >= sizeof(*node), ("sfs node size is too small")); + node = malloc(size, M_SFSNODES, M_WAITOK | M_ZERO); + strlcpy(node->sn_name, name, sizeof(node->sn_name)); + node->sn_parent_id = parent_id; + node->sn_id = id; + + return (node); +} + +static void +sfs_destroy_node(sfs_node_t *node) +{ + free(node, M_SFSNODES); +} + +static void * +sfs_reclaim_vnode(vnode_t *vp) +{ + sfs_node_t *node; + void *data; + + sfs_vnode_remove(vp); + data = vp->v_data; + vp->v_data = NULL; + return (data); +} + +static int +sfs_readdir_common(uint64_t parent_id, uint64_t id, struct vop_readdir_args *ap, + uio_t *uio, off_t *offp) +{ + struct dirent entry; + int error; + + /* Reset ncookies for subsequent use of vfs_read_dirent. */ + if (ap->a_ncookies != NULL) + *ap->a_ncookies = 0; -/* include . and .. in the calculation */ -#define NROOT_ENTRIES ((sizeof (zfsctl_root_entries) / \ - sizeof (gfs_dirent_t)) + 1) + if (uio->uio_resid < sizeof(entry)) + return (SET_ERROR(EINVAL)); + + if (uio->uio_offset < 0) + return (SET_ERROR(EINVAL)); + if (uio->uio_offset == 0) { + entry.d_fileno = id; + entry.d_type = DT_DIR; + entry.d_name[0] = '.'; + entry.d_name[1] = '\0'; + entry.d_namlen = 1; + entry.d_reclen = sizeof(entry); + error = vfs_read_dirent(ap, &entry, uio->uio_offset); + if (error != 0) + return (SET_ERROR(error)); + } + + if (uio->uio_offset < sizeof(entry)) + return (SET_ERROR(EINVAL)); + if (uio->uio_offset == sizeof(entry)) { + entry.d_fileno = parent_id; + entry.d_type = DT_DIR; + entry.d_name[0] = '.'; + entry.d_name[1] = '.'; + entry.d_name[2] = '\0'; + entry.d_namlen = 2; + entry.d_reclen = sizeof(entry); + error = vfs_read_dirent(ap, &entry, uio->uio_offset); + if (error != 0) + return (SET_ERROR(error)); + } + + if (offp != NULL) + *offp = 2 * sizeof(entry); + return (0); +} /* - * Initialize the various GFS pieces we'll need to create and manipulate .zfs - * directories. This is called from the ZFS init routine, and initializes the - * vnode ops vectors that we'll be using. + * .zfs inode namespace + * + * We need to generate unique inode numbers for all files and directories + * within the .zfs pseudo-filesystem. We use the following scheme: + * + * ENTRY ZFSCTL_INODE + * .zfs 1 + * .zfs/snapshot 2 + * .zfs/snapshot/<snap> objectid(snap) */ +#define ZFSCTL_INO_SNAP(id) (id) + +static struct vop_vector zfsctl_ops_root; +static struct vop_vector zfsctl_ops_snapdir; +static struct vop_vector zfsctl_ops_snapshot; +static struct vop_vector zfsctl_ops_shares_dir; + void zfsctl_init(void) { -#ifdef illumos - VERIFY(gfs_make_opsvec(zfsctl_opsvec) == 0); -#endif } void zfsctl_fini(void) { -#ifdef illumos - /* - * Remove vfsctl vnode ops - */ - if (zfsctl_ops_root) - vn_freevnodeops(zfsctl_ops_root); - if (zfsctl_ops_snapdir) - vn_freevnodeops(zfsctl_ops_snapdir); - if (zfsctl_ops_snapshot) - vn_freevnodeops(zfsctl_ops_snapshot); - if (zfsctl_ops_shares) - vn_freevnodeops(zfsctl_ops_shares); - if (zfsctl_ops_shares_dir) - vn_freevnodeops(zfsctl_ops_shares_dir); - - zfsctl_ops_root = NULL; - zfsctl_ops_snapdir = NULL; - zfsctl_ops_snapshot = NULL; - zfsctl_ops_shares = NULL; - zfsctl_ops_shares_dir = NULL; -#endif /* illumos */ } boolean_t @@ -208,106 +321,114 @@ zfsctl_is_node(vnode_t *vp) return (vn_matchops(vp, zfsctl_ops_root) || vn_matchops(vp, zfsctl_ops_snapdir) || vn_matchops(vp, zfsctl_ops_snapshot) || - vn_matchops(vp, zfsctl_ops_shares) || vn_matchops(vp, zfsctl_ops_shares_dir)); } -/* - * Return the inode number associated with the 'snapshot' or - * 'shares' directory. - */ -/* ARGSUSED */ -static ino64_t -zfsctl_root_inode_cb(vnode_t *vp, int index) -{ - zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - - ASSERT(index < 2); - - if (index == 0) - return (ZFSCTL_INO_SNAPDIR); +typedef struct zfsctl_root { + sfs_node_t node; + sfs_node_t *snapdir; + timestruc_t cmtime; +} zfsctl_root_t; - return (zfsvfs->z_shares_dir); -} /* - * Create the '.zfs' directory. This directory is cached as part of the VFS - * structure. This results in a hold on the vfs_t. The code in zfs_umount() - * therefore checks against a vfs_count of 2 instead of 1. This reference - * is removed when the ctldir is destroyed in the unmount. + * Create the '.zfs' directory. */ void zfsctl_create(zfsvfs_t *zfsvfs) { - vnode_t *vp, *rvp; - zfsctl_node_t *zcp; + zfsctl_root_t *dot_zfs; + sfs_node_t *snapdir; + vnode_t *rvp; uint64_t crtime[2]; ASSERT(zfsvfs->z_ctldir == NULL); - vp = gfs_root_create(sizeof (zfsctl_node_t), zfsvfs->z_vfs, - &zfsctl_ops_root, ZFSCTL_INO_ROOT, zfsctl_root_entries, - zfsctl_root_inode_cb, MAXNAMELEN, NULL, NULL); - zcp = vp->v_data; - zcp->zc_id = ZFSCTL_INO_ROOT; + snapdir = sfs_alloc_node(sizeof(*snapdir), "snapshot", ZFSCTL_INO_ROOT, + ZFSCTL_INO_SNAPDIR); + dot_zfs = (zfsctl_root_t *)sfs_alloc_node(sizeof(*dot_zfs), ".zfs", 0, + ZFSCTL_INO_ROOT); + dot_zfs->snapdir = snapdir; VERIFY(VFS_ROOT(zfsvfs->z_vfs, LK_EXCLUSIVE, &rvp) == 0); VERIFY(0 == sa_lookup(VTOZ(rvp)->z_sa_hdl, SA_ZPL_CRTIME(zfsvfs), - &crtime, sizeof (crtime))); - ZFS_TIME_DECODE(&zcp->zc_cmtime, crtime); - VN_URELE(rvp); - - /* - * We're only faking the fact that we have a root of a filesystem for - * the sake of the GFS interfaces. Undo the flag manipulation it did - * for us. - */ - vp->v_vflag &= ~VV_ROOT; - - zfsvfs->z_ctldir = vp; + &crtime, sizeof(crtime))); + ZFS_TIME_DECODE(&dot_zfs->cmtime, crtime); + vput(rvp); - VOP_UNLOCK(vp, 0); + zfsvfs->z_ctldir = dot_zfs; } /* * Destroy the '.zfs' directory. Only called when the filesystem is unmounted. - * There might still be more references if we were force unmounted, but only - * new zfs_inactive() calls can occur and they don't reference .zfs + * The nodes must not have any associated vnodes by now as they should be + * vflush-ed. */ void zfsctl_destroy(zfsvfs_t *zfsvfs) { - VN_RELE(zfsvfs->z_ctldir); + sfs_destroy_node(zfsvfs->z_ctldir->snapdir); + sfs_destroy_node((sfs_node_t *)zfsvfs->z_ctldir); zfsvfs->z_ctldir = NULL; } -/* - * Given a root znode, retrieve the associated .zfs directory. - * Add a hold to the vnode and return it. - */ -vnode_t * -zfsctl_root(znode_t *zp) +static int +zfsctl_fs_root_vnode(struct mount *mp, void *arg __unused, int flags, + struct vnode **vpp) { - ASSERT(zfs_has_ctldir(zp)); - VN_HOLD(zp->z_zfsvfs->z_ctldir); - return (zp->z_zfsvfs->z_ctldir); + return (VFS_ROOT(mp, flags, vpp)); +} + +static void +zfsctl_common_vnode_setup(vnode_t *vp, void *arg) +{ + ASSERT_VOP_ELOCKED(vp, __func__); + + /* We support shared locking. */ + VN_LOCK_ASHARE(vp); + vp->v_type = VDIR; + vp->v_data = arg; } static int -zfsctl_common_print(ap) - struct vop_print_args /* { - struct vnode *a_vp; - } */ *ap; +zfsctl_root_vnode(struct mount *mp, void *arg __unused, int flags, + struct vnode **vpp) { - vnode_t *vp = ap->a_vp; - gfs_file_t *fp = vp->v_data; + void *node; + int err; - printf(" parent = %p\n", fp->gfs_parent); - printf(" type = %d\n", fp->gfs_type); - printf(" index = %d\n", fp->gfs_index); - printf(" ino = %ju\n", (uintmax_t)fp->gfs_ino); - return (0); + node = ((zfsvfs_t*)mp->mnt_data)->z_ctldir; + err = sfs_vgetx(mp, flags, 0, ZFSCTL_INO_ROOT, "zfs", &zfsctl_ops_root, + zfsctl_common_vnode_setup, node, vpp); + return (err); +} + +static int +zfsctl_snapdir_vnode(struct mount *mp, void *arg __unused, int flags, + struct vnode **vpp) +{ + void *node; + int err; + + node = ((zfsvfs_t*)mp->mnt_data)->z_ctldir->snapdir; + err = sfs_vgetx(mp, flags, ZFSCTL_INO_ROOT, ZFSCTL_INO_SNAPDIR, "zfs", + &zfsctl_ops_snapdir, zfsctl_common_vnode_setup, node, vpp); + return (err); +} + +/* + * Given a root znode, retrieve the associated .zfs directory. + * Add a hold to the vnode and return it. + */ +int +zfsctl_root(zfsvfs_t *zfsvfs, int flags, vnode_t **vpp) +{ + vnode_t *vp; + int error; + + error = zfsctl_root_vnode(zfsvfs->z_vfs, NULL, flags, vpp); + return (error); } /* @@ -350,18 +471,8 @@ zfsctl_common_access(ap) { accmode_t accmode = ap->a_accmode; -#ifdef TODO - if (flags & V_ACE_MASK) { - if (accmode & ACE_ALL_WRITE_PERMS) - return (SET_ERROR(EACCES)); - } else { -#endif - if (accmode & VWRITE) - return (SET_ERROR(EACCES)); -#ifdef TODO - } -#endif - + if (accmode & VWRITE) + return (SET_ERROR(EACCES)); return (0); } @@ -372,6 +483,9 @@ static void zfsctl_common_getattr(vnode_t *vp, vattr_t *vap) { timestruc_t now; + sfs_node_t *node; + + node = vp->v_data; vap->va_uid = 0; vap->va_gid = 0; @@ -394,6 +508,11 @@ zfsctl_common_getattr(vnode_t *vp, vattr_t *vap) vap->va_atime = now; /* FreeBSD: Reset chflags(2) flags. */ vap->va_flags = 0; + + vap->va_nodeid = node->sn_id; + + /* At least '.' and '..'. */ + vap->va_nlink = 2; } /*ARGSUSED*/ @@ -406,81 +525,46 @@ zfsctl_common_fid(ap) { vnode_t *vp = ap->a_vp; fid_t *fidp = (void *)ap->a_fid; - zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - zfsctl_node_t *zcp = vp->v_data; - uint64_t object = zcp->zc_id; + sfs_node_t *node = vp->v_data; + uint64_t object = node->sn_id; zfid_short_t *zfid; int i; - ZFS_ENTER(zfsvfs); - -#ifdef illumos - if (fidp->fid_len < SHORT_FID_LEN) { - fidp->fid_len = SHORT_FID_LEN; - ZFS_EXIT(zfsvfs); - return (SET_ERROR(ENOSPC)); - } -#endif - zfid = (zfid_short_t *)fidp; - zfid->zf_len = SHORT_FID_LEN; - for (i = 0; i < sizeof (zfid->zf_object); i++) + for (i = 0; i < sizeof(zfid->zf_object); i++) zfid->zf_object[i] = (uint8_t)(object >> (8 * i)); - /* .zfs znodes always have a generation number of 0 */ - for (i = 0; i < sizeof (zfid->zf_gen); i++) + /* .zfs nodes always have a generation number of 0 */ + for (i = 0; i < sizeof(zfid->zf_gen); i++) zfid->zf_gen[i] = 0; - ZFS_EXIT(zfsvfs); return (0); } - -/*ARGSUSED*/ static int -zfsctl_shares_fid(ap) - struct vop_fid_args /* { +zfsctl_common_reclaim(ap) + struct vop_reclaim_args /* { struct vnode *a_vp; - struct fid *a_fid; + struct thread *a_td; } */ *ap; { - vnode_t *vp = ap->a_vp; - fid_t *fidp = (void *)ap->a_fid; - zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - znode_t *dzp; - int error; - - ZFS_ENTER(zfsvfs); - - if (zfsvfs->z_shares_dir == 0) { - ZFS_EXIT(zfsvfs); - return (SET_ERROR(ENOTSUP)); - } - - if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { - error = VOP_FID(ZTOV(dzp), fidp); - VN_RELE(ZTOV(dzp)); - } + vnode_t *vp = ap->a_vp; - ZFS_EXIT(zfsvfs); - return (error); + (void) sfs_reclaim_vnode(vp); + return (0); } -/* - * .zfs inode namespace - * - * We need to generate unique inode numbers for all files and directories - * within the .zfs pseudo-filesystem. We use the following scheme: - * - * ENTRY ZFSCTL_INODE - * .zfs 1 - * .zfs/snapshot 2 - * .zfs/snapshot/<snap> objectid(snap) - */ - -#define ZFSCTL_INO_SNAP(id) (id) +static int +zfsctl_common_print(ap) + struct vop_print_args /* { + struct vnode *a_vp; + } */ *ap; +{ + sfs_print_node(ap->a_vp->v_data); + return (0); +} /* * Get root directory attributes. @@ -496,155 +580,131 @@ zfsctl_root_getattr(ap) { struct vnode *vp = ap->a_vp; struct vattr *vap = ap->a_vap; - zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - zfsctl_node_t *zcp = vp->v_data; - - ZFS_ENTER(zfsvfs); - vap->va_nodeid = ZFSCTL_INO_ROOT; - vap->va_nlink = vap->va_size = NROOT_ENTRIES; - vap->va_mtime = vap->va_ctime = zcp->zc_cmtime; - vap->va_birthtime = vap->va_ctime; + zfsctl_root_t *node = vp->v_data; zfsctl_common_getattr(vp, vap); - ZFS_EXIT(zfsvfs); - + vap->va_ctime = node->cmtime; + vap->va_mtime = vap->va_ctime; + vap->va_birthtime = vap->va_ctime; + vap->va_nlink += 1; /* snapdir */ + vap->va_size = vap->va_nlink; return (0); } /* - * Special case the handling of "..". + * When we lookup "." we still can be asked to lock it + * differently, can't we? */ -/* ARGSUSED */ int -zfsctl_root_lookup(vnode_t *dvp, char *nm, vnode_t **vpp, pathname_t *pnp, - int flags, vnode_t *rdir, cred_t *cr, caller_context_t *ct, - int *direntflags, pathname_t *realpnp) +zfsctl_relock_dot(vnode_t *dvp, int ltype) { - zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; - int err; - - /* - * No extended attributes allowed under .zfs - */ - if (flags & LOOKUP_XATTR) - return (SET_ERROR(EINVAL)); - - ZFS_ENTER(zfsvfs); - - if (strcmp(nm, "..") == 0) { -#ifdef illumos - err = VFS_ROOT(dvp->v_vfsp, LK_EXCLUSIVE, vpp); -#else - /* - * NB: can not use VFS_ROOT here as it would acquire - * the vnode lock of the parent (root) vnode while - * holding the child's (.zfs) lock. - */ - znode_t *rootzp; - - err = zfs_zget(zfsvfs, zfsvfs->z_root, &rootzp); - if (err == 0) - *vpp = ZTOV(rootzp); -#endif - } else { - err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir, - cr, ct, direntflags, realpnp); + vref(dvp); + if (ltype != VOP_ISLOCKED(dvp)) { + if (ltype == LK_EXCLUSIVE) + vn_lock(dvp, LK_UPGRADE | LK_RETRY); + else /* if (ltype == LK_SHARED) */ + vn_lock(dvp, LK_DOWNGRADE | LK_RETRY); + + /* Relock for the "." case may left us with reclaimed vnode. */ + if ((dvp->v_iflag & VI_DOOMED) != 0) { + vrele(dvp); + return (SET_ERROR(ENOENT)); + } } - - ZFS_EXIT(zfsvfs); - - return (err); + return (0); } -static int -zfsctl_freebsd_root_lookup(ap) +/* + * Special case the handling of "..". + */ +int +zfsctl_root_lookup(ap) struct vop_lookup_args /* { struct vnode *a_dvp; struct vnode **a_vpp; struct componentname *a_cnp; } */ *ap; { + struct componentname *cnp = ap->a_cnp; vnode_t *dvp = ap->a_dvp; vnode_t **vpp = ap->a_vpp; cred_t *cr = ap->a_cnp->cn_cred; int flags = ap->a_cnp->cn_flags; int lkflags = ap->a_cnp->cn_lkflags; int nameiop = ap->a_cnp->cn_nameiop; - char nm[NAME_MAX + 1]; int err; + int ltype; - if ((flags & ISLASTCN) && (nameiop == RENAME || nameiop == CREATE)) - return (EOPNOTSUPP); - - ASSERT(ap->a_cnp->cn_namelen < sizeof(nm)); - strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1); -relookup: - err = zfsctl_root_lookup(dvp, nm, vpp, NULL, 0, NULL, cr, NULL, NULL, NULL); - if (err == 0 && (nm[0] != '.' || nm[1] != '\0')) { - if (flags & ISDOTDOT) { - VOP_UNLOCK(dvp, 0); - err = vn_lock(*vpp, lkflags); - if (err != 0) { - vrele(*vpp); - *vpp = NULL; - } - vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY); - } else { - err = vn_lock(*vpp, LK_EXCLUSIVE); - if (err != 0) { - VERIFY3S(err, ==, ENOENT); - goto relookup; - } - } + ASSERT(dvp->v_type == VDIR); + + if ((flags & ISLASTCN) != 0 && nameiop != LOOKUP) + return (SET_ERROR(ENOTSUP)); + + if (cnp->cn_namelen == 1 && *cnp->cn_nameptr == '.') { + err = zfsctl_relock_dot(dvp, lkflags & LK_TYPE_MASK); + if (err == 0) + *vpp = dvp; + } else if ((flags & ISDOTDOT) != 0) { + err = vn_vget_ino_gen(dvp, zfsctl_fs_root_vnode, NULL, + lkflags, vpp); + } else if (strncmp(cnp->cn_nameptr, "snapshot", cnp->cn_namelen) == 0) { + err = zfsctl_snapdir_vnode(dvp->v_mount, NULL, lkflags, vpp); + } else { + err = SET_ERROR(ENOENT); } + if (err != 0) + *vpp = NULL; return (err); } static int -zfsctl_root_print(ap) - struct vop_print_args /* { +zfsctl_root_readdir(ap) + struct vop_readdir_args /* { struct vnode *a_vp; + struct uio *a_uio; + struct ucred *a_cred; + int *a_eofflag; + int *ncookies; + u_long **a_cookies; } */ *ap; { - printf(" .zfs node\n"); - zfsctl_common_print(ap); - return (0); -} + struct dirent entry; + vnode_t *vp = ap->a_vp; + zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; + zfsctl_root_t *node = vp->v_data; + uio_t *uio = ap->a_uio; + int *eofp = ap->a_eofflag; + off_t dots_offset; + int error; -#ifdef illumos -static int -zfsctl_pathconf(vnode_t *vp, int cmd, ulong_t *valp, cred_t *cr, - caller_context_t *ct) -{ - /* - * We only care about ACL_ENABLED so that libsec can - * display ACL correctly and not default to POSIX draft. - */ - if (cmd == _PC_ACL_ENABLED) { - *valp = _ACL_ACE_ENABLED; - return (0); + ASSERT(vp->v_type == VDIR); + + error = sfs_readdir_common(zfsvfs->z_root, ZFSCTL_INO_ROOT, ap, uio, + &dots_offset); + if (error != 0) { + if (error == ENAMETOOLONG) /* ran out of destination space */ + error = 0; + return (error); } + if (uio->uio_offset != dots_offset) + return (SET_ERROR(EINVAL)); - return (fs_pathconf(vp, cmd, valp, cr, ct)); + CTASSERT(sizeof(node->snapdir->sn_name) <= sizeof(entry.d_name)); + entry.d_fileno = node->snapdir->sn_id; + entry.d_type = DT_DIR; + strcpy(entry.d_name, node->snapdir->sn_name); + entry.d_namlen = strlen(entry.d_name); + entry.d_reclen = sizeof(entry); + error = vfs_read_dirent(ap, &entry, uio->uio_offset); + if (error != 0) { + if (error == ENAMETOOLONG) + error = 0; + return (SET_ERROR(error)); + } + if (eofp != NULL) + *eofp = 1; + return (0); } -#endif /* illumos */ - -#ifdef illumos -static const fs_operation_def_t zfsctl_tops_root[] = { - { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, - { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, - { VOPNAME_IOCTL, { .error = fs_inval } }, - { VOPNAME_GETATTR, { .vop_getattr = zfsctl_root_getattr } }, - { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, - { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, - { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_root_lookup } }, - { VOPNAME_SEEK, { .vop_seek = fs_seek } }, - { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } }, - { VOPNAME_PATHCONF, { .vop_pathconf = zfsctl_pathconf } }, - { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, - { NULL } -}; -#endif /* illumos */ static struct vop_vector zfsctl_ops_root = { .vop_default = &default_vnodeops, @@ -653,29 +713,19 @@ static struct vop_vector zfsctl_ops_root = { .vop_ioctl = VOP_EINVAL, .vop_getattr = zfsctl_root_getattr, .vop_access = zfsctl_common_access, - .vop_readdir = gfs_vop_readdir, - .vop_lookup = zfsctl_freebsd_root_lookup, + .vop_readdir = zfsctl_root_readdir, + .vop_lookup = zfsctl_root_lookup, .vop_inactive = VOP_NULL, - .vop_reclaim = gfs_vop_reclaim, -#ifdef TODO - .vop_pathconf = zfsctl_pathconf, -#endif + .vop_reclaim = zfsctl_common_reclaim, .vop_fid = zfsctl_common_fid, - .vop_print = zfsctl_root_print, + .vop_print = zfsctl_common_print, }; -/* - * Gets the full dataset name that corresponds to the given snapshot name - * Example: - * zfsctl_snapshot_zname("snap1") -> "mypool/myfs@snap1" - */ static int zfsctl_snapshot_zname(vnode_t *vp, const char *name, int len, char *zname) { objset_t *os = ((zfsvfs_t *)((vp)->v_vfsp->vfs_data))->z_os; - if (zfs_component_namecheck(name, NULL, NULL) != 0) - return (SET_ERROR(EILSEQ)); dmu_objset_name(os, zname); if (strlen(zname) + 1 + strlen(name) >= len) return (SET_ERROR(ENAMETOOLONG)); @@ -685,272 +735,62 @@ zfsctl_snapshot_zname(vnode_t *vp, const char *name, int len, char *zname) } static int -zfsctl_unmount_snap(zfs_snapentry_t *sep, int fflags, cred_t *cr) -{ - vnode_t *svp = sep->se_root; - int error; - - ASSERT(vn_ismntpt(svp)); - - /* this will be dropped by dounmount() */ - if ((error = vn_vfswlock(svp)) != 0) - return (error); - -#ifdef illumos - VN_HOLD(svp); - error = dounmount(vn_mountedvfs(svp), fflags, cr); - if (error) { - VN_RELE(svp); - return (error); - } - - /* - * We can't use VN_RELE(), as that will try to invoke - * zfsctl_snapdir_inactive(), which would cause us to destroy - * the sd_lock mutex held by our caller. - */ - ASSERT(svp->v_count == 1); - gfs_vop_reclaim(svp, cr, NULL); - - kmem_free(sep->se_name, strlen(sep->se_name) + 1); - kmem_free(sep, sizeof (zfs_snapentry_t)); - - return (0); -#else - vfs_ref(vn_mountedvfs(svp)); - return (dounmount(vn_mountedvfs(svp), fflags, curthread)); -#endif -} - -#ifdef illumos -static void -zfsctl_rename_snap(zfsctl_snapdir_t *sdp, zfs_snapentry_t *sep, const char *nm) -{ - avl_index_t where; - vfs_t *vfsp; - refstr_t *pathref; - char newpath[MAXNAMELEN]; - char *tail; - - ASSERT(MUTEX_HELD(&sdp->sd_lock)); - ASSERT(sep != NULL); - - vfsp = vn_mountedvfs(sep->se_root); - ASSERT(vfsp != NULL); - - vfs_lock_wait(vfsp); - - /* - * Change the name in the AVL tree. - */ - avl_remove(&sdp->sd_snaps, sep); - kmem_free(sep->se_name, strlen(sep->se_name) + 1); - sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); - (void) strcpy(sep->se_name, nm); - VERIFY(avl_find(&sdp->sd_snaps, sep, &where) == NULL); - avl_insert(&sdp->sd_snaps, sep, where); - - /* - * Change the current mountpoint info: - * - update the tail of the mntpoint path - * - update the tail of the resource path - */ - pathref = vfs_getmntpoint(vfsp); - (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); - VERIFY((tail = strrchr(newpath, '/')) != NULL); - *(tail+1) = '\0'; - ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); - (void) strcat(newpath, nm); - refstr_rele(pathref); - vfs_setmntpoint(vfsp, newpath, 0); - - pathref = vfs_getresource(vfsp); - (void) strncpy(newpath, refstr_value(pathref), sizeof (newpath)); - VERIFY((tail = strrchr(newpath, '@')) != NULL); - *(tail+1) = '\0'; - ASSERT3U(strlen(newpath) + strlen(nm), <, sizeof (newpath)); - (void) strcat(newpath, nm); - refstr_rele(pathref); - vfs_setresource(vfsp, newpath, 0); - - vfs_unlock(vfsp); -} -#endif /* illumos */ - -#ifdef illumos -/*ARGSUSED*/ -static int -zfsctl_snapdir_rename(vnode_t *sdvp, char *snm, vnode_t *tdvp, char *tnm, - cred_t *cr, caller_context_t *ct, int flags) -{ - zfsctl_snapdir_t *sdp = sdvp->v_data; - zfs_snapentry_t search, *sep; - zfsvfs_t *zfsvfs; - avl_index_t where; - char from[ZFS_MAX_DATASET_NAME_LEN], to[ZFS_MAX_DATASET_NAME_LEN]; - char real[ZFS_MAX_DATASET_NAME_LEN], fsname[ZFS_MAX_DATASET_NAME_LEN]; - int err; - - zfsvfs = sdvp->v_vfsp->vfs_data; - ZFS_ENTER(zfsvfs); - - if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { - err = dmu_snapshot_realname(zfsvfs->z_os, snm, real, - sizeof (real), NULL); - if (err == 0) { - snm = real; - } else if (err != ENOTSUP) { - ZFS_EXIT(zfsvfs); - return (err); - } - } - - ZFS_EXIT(zfsvfs); - - dmu_objset_name(zfsvfs->z_os, fsname); - - err = zfsctl_snapshot_zname(sdvp, snm, sizeof (from), from); - if (err == 0) - err = zfsctl_snapshot_zname(tdvp, tnm, sizeof (to), to); - if (err == 0) - err = zfs_secpolicy_rename_perms(from, to, cr); - if (err != 0) - return (err); - - /* - * Cannot move snapshots out of the snapdir. - */ - if (sdvp != tdvp) - return (SET_ERROR(EINVAL)); - - if (strcmp(snm, tnm) == 0) - return (0); - - mutex_enter(&sdp->sd_lock); - - search.se_name = (char *)snm; - if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) == NULL) { - mutex_exit(&sdp->sd_lock); - return (SET_ERROR(ENOENT)); - } - - err = dsl_dataset_rename_snapshot(fsname, snm, tnm, 0); - if (err == 0) - zfsctl_rename_snap(sdp, sep, tnm); - - mutex_exit(&sdp->sd_lock); - - return (err); -} -#endif /* illumos */ - -#ifdef illumos -/* ARGSUSED */ -static int -zfsctl_snapdir_remove(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr, - caller_context_t *ct, int flags) +zfsctl_snapshot_lookup(vnode_t *vp, const char *name, uint64_t *id) { - zfsctl_snapdir_t *sdp = dvp->v_data; - zfs_snapentry_t *sep; - zfs_snapentry_t search; - zfsvfs_t *zfsvfs; - char snapname[ZFS_MAX_DATASET_NAME_LEN]; - char real[ZFS_MAX_DATASET_NAME_LEN]; + objset_t *os = ((zfsvfs_t *)((vp)->v_vfsp->vfs_data))->z_os; int err; - zfsvfs = dvp->v_vfsp->vfs_data; - ZFS_ENTER(zfsvfs); - - if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) { - - err = dmu_snapshot_realname(zfsvfs->z_os, name, real, - sizeof (real), NULL); - if (err == 0) { - name = real; - } else if (err != ENOTSUP) { - ZFS_EXIT(zfsvfs); - return (err); - } - } - - ZFS_EXIT(zfsvfs); - - err = zfsctl_snapshot_zname(dvp, name, sizeof (snapname), snapname); - if (err == 0) - err = zfs_secpolicy_destroy_perms(snapname, cr); - if (err != 0) - return (err); - - mutex_enter(&sdp->sd_lock); - - search.se_name = name; - sep = avl_find(&sdp->sd_snaps, &search, NULL); - if (sep) { - avl_remove(&sdp->sd_snaps, sep); - err = zfsctl_unmount_snap(sep, MS_FORCE, cr); - if (err != 0) - avl_add(&sdp->sd_snaps, sep); - else - err = dsl_destroy_snapshot(snapname, B_FALSE); - } else { - err = SET_ERROR(ENOENT); - } - - mutex_exit(&sdp->sd_lock); - + err = dsl_dataset_snap_lookup(dmu_objset_ds(os), name, id); return (err); } -#endif /* illumos */ /* - * This creates a snapshot under '.zfs/snapshot'. + * Given a vnode get a root vnode of a filesystem mounted on top of + * the vnode, if any. The root vnode is referenced and locked. + * If no filesystem is mounted then the orinal vnode remains referenced + * and locked. If any error happens the orinal vnode is unlocked and + * released. */ -/* ARGSUSED */ static int -zfsctl_snapdir_mkdir(vnode_t *dvp, char *dirname, vattr_t *vap, vnode_t **vpp, - cred_t *cr, caller_context_t *cc, int flags, vsecattr_t *vsecp) +zfsctl_mounted_here(vnode_t **vpp, int flags) { - zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; - char name[ZFS_MAX_DATASET_NAME_LEN]; + struct mount *mp; int err; - static enum symfollow follow = NO_FOLLOW; - static enum uio_seg seg = UIO_SYSSPACE; - if (zfs_component_namecheck(dirname, NULL, NULL) != 0) - return (SET_ERROR(EILSEQ)); + ASSERT_VOP_LOCKED(*vpp, __func__); + ASSERT3S((*vpp)->v_type, ==, VDIR); - dmu_objset_name(zfsvfs->z_os, name); - - *vpp = NULL; - - err = zfs_secpolicy_snapshot_perms(name, cr); - if (err != 0) + if ((mp = (*vpp)->v_mountedhere) != NULL) { + err = vfs_busy(mp, 0); + KASSERT(err == 0, ("vfs_busy(mp, 0) failed with %d", err)); + KASSERT(vrefcnt(*vpp) > 1, ("unreferenced mountpoint")); + vput(*vpp); + err = VFS_ROOT(mp, flags, vpp); + vfs_unbusy(mp); return (err); - - if (err == 0) { - err = dmu_objset_snapshot_one(name, dirname); - if (err != 0) - return (err); - err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp); } - - return (err); + return (EJUSTRETURN); } -static int -zfsctl_freebsd_snapdir_mkdir(ap) - struct vop_mkdir_args /* { - struct vnode *a_dvp; - struct vnode **a_vpp; - struct componentname *a_cnp; - struct vattr *a_vap; - } */ *ap; +typedef struct { + const char *snap_name; + uint64_t snap_id; +} snapshot_setup_arg_t; + +static void +zfsctl_snapshot_vnode_setup(vnode_t *vp, void *arg) { + snapshot_setup_arg_t *ssa = arg; + sfs_node_t *node; + + ASSERT_VOP_ELOCKED(vp, __func__); - ASSERT(ap->a_cnp->cn_flags & SAVENAME); + node = sfs_alloc_node(sizeof(sfs_node_t), + ssa->snap_name, ZFSCTL_INO_SNAPDIR, ssa->snap_id); + zfsctl_common_vnode_setup(vp, node); - return (zfsctl_snapdir_mkdir(ap->a_dvp, ap->a_cnp->cn_nameptr, NULL, - ap->a_vpp, ap->a_cnp->cn_cred, NULL, 0, NULL)); + /* We have to support recursive locking. */ + VN_LOCK_AREC(vp); } /* @@ -970,150 +810,100 @@ zfsctl_snapdir_lookup(ap) vnode_t *dvp = ap->a_dvp; vnode_t **vpp = ap->a_vpp; struct componentname *cnp = ap->a_cnp; - char nm[NAME_MAX + 1]; - zfsctl_snapdir_t *sdp = dvp->v_data; - objset_t *snap; - char snapname[ZFS_MAX_DATASET_NAME_LEN]; - char real[ZFS_MAX_DATASET_NAME_LEN]; + char name[NAME_MAX + 1]; + char fullname[ZFS_MAX_DATASET_NAME_LEN]; char *mountpoint; - zfs_snapentry_t *sep, search; size_t mountpoint_len; - avl_index_t where; zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; + uint64_t snap_id; + int nameiop = cnp->cn_nameiop; + int lkflags = cnp->cn_lkflags; + int flags = cnp->cn_flags; int err; - int ltype, flags = 0; - - /* - * No extended attributes allowed under .zfs - */ - if (flags & LOOKUP_XATTR) - return (SET_ERROR(EINVAL)); - ASSERT(ap->a_cnp->cn_namelen < sizeof(nm)); - strlcpy(nm, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1); ASSERT(dvp->v_type == VDIR); - *vpp = NULL; + if ((flags & ISLASTCN) != 0 && nameiop != LOOKUP) + return (SET_ERROR(ENOTSUP)); - /* - * If we get a recursive call, that means we got called - * from the domount() code while it was trying to look up the - * spec (which looks like a local path for zfs). We need to - * add some flag to domount() to tell it not to do this lookup. - */ - if (MUTEX_HELD(&sdp->sd_lock)) + if (cnp->cn_namelen == 1 && *cnp->cn_nameptr == '.') { + err = zfsctl_relock_dot(dvp, lkflags & LK_TYPE_MASK); + if (err == 0) + *vpp = dvp; + return (err); + } + if (flags & ISDOTDOT) { + err = vn_vget_ino_gen(dvp, zfsctl_root_vnode, NULL, lkflags, + vpp); + return (err); + } + + if (cnp->cn_namelen >= sizeof(name)) + return (SET_ERROR(ENAMETOOLONG)); + + strlcpy(name, ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen + 1); + err = zfsctl_snapshot_lookup(dvp, name, &snap_id); + if (err != 0) return (SET_ERROR(ENOENT)); - ZFS_ENTER(zfsvfs); - if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) { - if (nm[0] == '.' && nm[1] == '.' && nm[2] =='\0') { - VOP_UNLOCK(dvp, 0); - VERIFY0(vn_lock(*vpp, LK_EXCLUSIVE)); - VERIFY0(vn_lock(dvp, LK_EXCLUSIVE)); - } - ZFS_EXIT(zfsvfs); - return (0); - } + for (;;) { + snapshot_setup_arg_t ssa; + + ssa.snap_name = name; + ssa.snap_id = snap_id; + err = sfs_vgetx(dvp->v_mount, LK_SHARED, ZFSCTL_INO_SNAPDIR, + snap_id, "zfs", &zfsctl_ops_snapshot, + zfsctl_snapshot_vnode_setup, &ssa, vpp); + if (err != 0) + return (err); - if (flags & FIGNORECASE) { - boolean_t conflict = B_FALSE; + /* Check if a new vnode has just been created. */ + if (VOP_ISLOCKED(*vpp) == LK_EXCLUSIVE) + break; - err = dmu_snapshot_realname(zfsvfs->z_os, nm, real, - sizeof (real), &conflict); - if (err == 0) { - strlcpy(nm, real, sizeof(nm)); - } else if (err != ENOTSUP) { - ZFS_EXIT(zfsvfs); + /* + * The vnode must be referenced at least by this thread and + * the mounted snapshot or the thread doing the mounting. + * There can be more references from concurrent lookups. + */ + KASSERT(vrefcnt(*vpp) > 1, ("found unreferenced mountpoint")); + + /* + * Check if a snapshot is already mounted on top of the vnode. + */ + err = zfsctl_mounted_here(vpp, lkflags); + if (err != EJUSTRETURN) return (err); - } -#if 0 - if (realpnp) - (void) strlcpy(realpnp->pn_buf, nm, - realpnp->pn_bufsize); - if (conflict && direntflags) - *direntflags = ED_CASE_CONFLICT; -#endif - } -relookup: - mutex_enter(&sdp->sd_lock); - search.se_name = (char *)nm; - if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) != NULL) { - *vpp = sep->se_root; - VN_HOLD(*vpp); - err = traverse(vpp, LK_EXCLUSIVE | LK_RETRY); - if (err != 0) { - *vpp = NULL; - } else if (*vpp == sep->se_root) { - /* - * The snapshot was unmounted behind our backs, - * try to remount it. - */ - VERIFY(zfsctl_snapshot_zname(dvp, nm, MAXNAMELEN, snapname) == 0); - goto domount; - } - mutex_exit(&sdp->sd_lock); - ZFS_EXIT(zfsvfs); - return (err); - } +#ifdef INVARIANTS + /* + * If the vnode not covered yet, then the mount operation + * must be in progress. + */ + VI_LOCK(*vpp); + KASSERT(((*vpp)->v_iflag & VI_MOUNT) != 0, + ("snapshot vnode not covered")); + VI_UNLOCK(*vpp); +#endif + vput(*vpp); - /* - * The requested snapshot is not currently mounted, look it up. - */ - err = zfsctl_snapshot_zname(dvp, nm, sizeof (snapname), snapname); - if (err != 0) { - mutex_exit(&sdp->sd_lock); - ZFS_EXIT(zfsvfs); /* - * handle "ls *" or "?" in a graceful manner, - * forcing EILSEQ to ENOENT. - * Since shell ultimately passes "*" or "?" as name to lookup + * In this situation we can loop on uncontested locks and starve + * the thread doing the lengthy, non-trivial mount operation. */ - return (err == EILSEQ ? ENOENT : err); - } - if (dmu_objset_hold(snapname, FTAG, &snap) != 0) { - mutex_exit(&sdp->sd_lock); -#ifdef illumos - ZFS_EXIT(zfsvfs); - return (SET_ERROR(ENOENT)); -#else /* !illumos */ - /* Translate errors and add SAVENAME when needed. */ - if ((cnp->cn_flags & ISLASTCN) && cnp->cn_nameiop == CREATE) { - err = EJUSTRETURN; - cnp->cn_flags |= SAVENAME; - } else { - err = SET_ERROR(ENOENT); - } - ZFS_EXIT(zfsvfs); - return (err); -#endif /* illumos */ + kern_yield(PRI_USER); } - sep = kmem_alloc(sizeof (zfs_snapentry_t), KM_SLEEP); - sep->se_name = kmem_alloc(strlen(nm) + 1, KM_SLEEP); - (void) strcpy(sep->se_name, nm); - *vpp = sep->se_root = zfsctl_snapshot_mknode(dvp, dmu_objset_id(snap)); - avl_insert(&sdp->sd_snaps, sep, where); + VERIFY0(zfsctl_snapshot_zname(dvp, name, sizeof(fullname), fullname)); - dmu_objset_rele(snap, FTAG); -domount: mountpoint_len = strlen(dvp->v_vfsp->mnt_stat.f_mntonname) + - strlen("/" ZFS_CTLDIR_NAME "/snapshot/") + strlen(nm) + 1; + strlen("/" ZFS_CTLDIR_NAME "/snapshot/") + strlen(name) + 1; mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP); (void) snprintf(mountpoint, mountpoint_len, "%s/" ZFS_CTLDIR_NAME "/snapshot/%s", - dvp->v_vfsp->mnt_stat.f_mntonname, nm); - mutex_exit(&sdp->sd_lock); + dvp->v_vfsp->mnt_stat.f_mntonname, name); - /* - * The vnode may get reclaimed between dropping sd_lock and - * getting the vnode lock. - * */ - err = vn_lock(*vpp, LK_EXCLUSIVE); - if (err == ENOENT) - goto relookup; - VERIFY0(err); - err = mount_snapshot(curthread, vpp, "zfs", mountpoint, snapname, 0); + err = mount_snapshot(curthread, vpp, "zfs", mountpoint, fullname, 0); kmem_free(mountpoint, mountpoint_len); if (err == 0) { /* @@ -1125,231 +915,79 @@ domount: */ ASSERT(VTOZ(*vpp)->z_zfsvfs != zfsvfs); VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs; - (*vpp)->v_flag &= ~VROOT; - } - ZFS_EXIT(zfsvfs); -#ifdef illumos - /* - * If we had an error, drop our hold on the vnode and - * zfsctl_snapshot_inactive() will clean up. - */ - if (err != 0) { - VN_RELE(*vpp); - *vpp = NULL; + /* Clear the root flag (set via VFS_ROOT) as well. */ + (*vpp)->v_vflag &= ~VV_ROOT; } -#else + if (err != 0) *vpp = NULL; -#endif return (err); } -/* ARGSUSED */ -int -zfsctl_shares_lookup(ap) - struct vop_lookup_args /* { - struct vnode *a_dvp; - struct vnode **a_vpp; - struct componentname *a_cnp; - } */ *ap; -{ - vnode_t *dvp = ap->a_dvp; - vnode_t **vpp = ap->a_vpp; - struct componentname *cnp = ap->a_cnp; - zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data; - char nm[NAME_MAX + 1]; - znode_t *dzp; - int error; - - ZFS_ENTER(zfsvfs); - - ASSERT(cnp->cn_namelen < sizeof(nm)); - strlcpy(nm, cnp->cn_nameptr, cnp->cn_namelen + 1); - - if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) { - if (nm[0] == '.' && nm[1] == '.' && nm[2] =='\0') { - VOP_UNLOCK(dvp, 0); - VERIFY0(vn_lock(*vpp, LK_EXCLUSIVE)); - VERIFY0(vn_lock(dvp, LK_EXCLUSIVE)); - } - ZFS_EXIT(zfsvfs); - return (0); - } - - if (zfsvfs->z_shares_dir == 0) { - ZFS_EXIT(zfsvfs); - return (SET_ERROR(ENOTSUP)); - } - if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { - error = VOP_LOOKUP(ZTOV(dzp), vpp, cnp); - VN_RELE(ZTOV(dzp)); - } - - ZFS_EXIT(zfsvfs); - - return (error); -} - -/* ARGSUSED */ static int -zfsctl_snapdir_readdir_cb(vnode_t *vp, void *dp, int *eofp, - offset_t *offp, offset_t *nextp, void *data, int flags) -{ - zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - char snapname[ZFS_MAX_DATASET_NAME_LEN]; - uint64_t id, cookie; - boolean_t case_conflict; - int error; - - ZFS_ENTER(zfsvfs); - - cookie = *offp; - dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG); - error = dmu_snapshot_list_next(zfsvfs->z_os, - sizeof (snapname), snapname, &id, &cookie, &case_conflict); - dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG); - if (error) { - ZFS_EXIT(zfsvfs); - if (error == ENOENT) { - *eofp = 1; - return (0); - } - return (error); - } - - if (flags & V_RDDIR_ENTFLAGS) { - edirent_t *eodp = dp; - - (void) strcpy(eodp->ed_name, snapname); - eodp->ed_ino = ZFSCTL_INO_SNAP(id); - eodp->ed_eflags = case_conflict ? ED_CASE_CONFLICT : 0; - } else { - struct dirent64 *odp = dp; - - (void) strcpy(odp->d_name, snapname); - odp->d_ino = ZFSCTL_INO_SNAP(id); - } - *nextp = cookie; - - ZFS_EXIT(zfsvfs); - - return (0); -} - -/* ARGSUSED */ -static int -zfsctl_shares_readdir(ap) +zfsctl_snapdir_readdir(ap) struct vop_readdir_args /* { struct vnode *a_vp; struct uio *a_uio; struct ucred *a_cred; int *a_eofflag; - int *a_ncookies; + int *ncookies; u_long **a_cookies; } */ *ap; { + char snapname[ZFS_MAX_DATASET_NAME_LEN]; + struct dirent entry; vnode_t *vp = ap->a_vp; - uio_t *uiop = ap->a_uio; - cred_t *cr = ap->a_cred; - int *eofp = ap->a_eofflag; zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - znode_t *dzp; + uio_t *uio = ap->a_uio; + int *eofp = ap->a_eofflag; + off_t dots_offset; int error; - ZFS_ENTER(zfsvfs); + ASSERT(vp->v_type == VDIR); - if (zfsvfs->z_shares_dir == 0) { - ZFS_EXIT(zfsvfs); - return (SET_ERROR(ENOTSUP)); - } - if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { - vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY); - error = VOP_READDIR(ZTOV(dzp), uiop, cr, eofp, ap->a_ncookies, ap->a_cookies); - VN_URELE(ZTOV(dzp)); - } else { - *eofp = 1; - error = SET_ERROR(ENOENT); + error = sfs_readdir_common(ZFSCTL_INO_ROOT, ZFSCTL_INO_SNAPDIR, ap, uio, + &dots_offset); + if (error != 0) { + if (error == ENAMETOOLONG) /* ran out of destination space */ + error = 0; + return (error); } - ZFS_EXIT(zfsvfs); - return (error); -} - -/* - * pvp is the '.zfs' directory (zfsctl_node_t). - * - * Creates vp, which is '.zfs/snapshot' (zfsctl_snapdir_t). - * - * This function is the callback to create a GFS vnode for '.zfs/snapshot' - * when a lookup is performed on .zfs for "snapshot". - */ -vnode_t * -zfsctl_mknode_snapdir(vnode_t *pvp) -{ - vnode_t *vp; - zfsctl_snapdir_t *sdp; - - vp = gfs_dir_create(sizeof (zfsctl_snapdir_t), pvp, pvp->v_vfsp, - &zfsctl_ops_snapdir, NULL, NULL, MAXNAMELEN, - zfsctl_snapdir_readdir_cb, NULL); - sdp = vp->v_data; - sdp->sd_node.zc_id = ZFSCTL_INO_SNAPDIR; - sdp->sd_node.zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime; - mutex_init(&sdp->sd_lock, NULL, MUTEX_DEFAULT, NULL); - avl_create(&sdp->sd_snaps, snapentry_compare, - sizeof (zfs_snapentry_t), offsetof(zfs_snapentry_t, se_node)); - VOP_UNLOCK(vp, 0); - return (vp); -} - -vnode_t * -zfsctl_mknode_shares(vnode_t *pvp) -{ - vnode_t *vp; - zfsctl_node_t *sdp; - - vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, pvp->v_vfsp, - &zfsctl_ops_shares, NULL, NULL, MAXNAMELEN, - NULL, NULL); - sdp = vp->v_data; - sdp->zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime; - VOP_UNLOCK(vp, 0); - return (vp); - -} - -/* ARGSUSED */ -static int -zfsctl_shares_getattr(ap) - struct vop_getattr_args /* { - struct vnode *a_vp; - struct vattr *a_vap; - struct ucred *a_cred; - struct thread *a_td; - } */ *ap; -{ - vnode_t *vp = ap->a_vp; - vattr_t *vap = ap->a_vap; - cred_t *cr = ap->a_cred; - zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - znode_t *dzp; - int error; + for (;;) { + uint64_t cookie; + uint64_t id; + + cookie = uio->uio_offset - dots_offset; + + dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG); + error = dmu_snapshot_list_next(zfsvfs->z_os, sizeof(snapname), + snapname, &id, &cookie, NULL); + dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG); + if (error != 0) { + if (error == ENOENT) { + if (eofp != NULL) + *eofp = 1; + error = 0; + } + return (error); + } - ZFS_ENTER(zfsvfs); - if (zfsvfs->z_shares_dir == 0) { - ZFS_EXIT(zfsvfs); - return (SET_ERROR(ENOTSUP)); - } - if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) { - vn_lock(ZTOV(dzp), LK_SHARED | LK_RETRY); - error = VOP_GETATTR(ZTOV(dzp), vap, cr); - VN_URELE(ZTOV(dzp)); + entry.d_fileno = id; + entry.d_type = DT_DIR; + strcpy(entry.d_name, snapname); + entry.d_namlen = strlen(entry.d_name); + entry.d_reclen = sizeof(entry); + error = vfs_read_dirent(ap, &entry, uio->uio_offset); + if (error != 0) { + if (error == ENAMETOOLONG) + error = 0; + return (SET_ERROR(error)); + } + uio->uio_offset = cookie + dots_offset; } - ZFS_EXIT(zfsvfs); - return (error); - - + /* NOTREACHED */ } /* ARGSUSED */ @@ -1364,151 +1002,40 @@ zfsctl_snapdir_getattr(ap) vnode_t *vp = ap->a_vp; vattr_t *vap = ap->a_vap; zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data; - zfsctl_snapdir_t *sdp = vp->v_data; + dsl_dataset_t *ds = dmu_objset_ds(zfsvfs->z_os); + sfs_node_t *node = vp->v_data; + uint64_t snap_count; + int err; - ZFS_ENTER(zfsvfs); zfsctl_common_getattr(vp, vap); - vap->va_nodeid = gfs_file_inode(vp); - vap->va_nlink = vap->va_size = avl_numnodes(&sdp->sd_snaps) + 2; - vap->va_ctime = vap->va_mtime = dmu_objset_snap_cmtime(zfsvfs->z_os); + vap->va_ctime = dmu_objset_snap_cmtime(zfsvfs->z_os); + vap->va_mtime = vap->va_ctime; vap->va_birthtime = vap->va_ctime; - ZFS_EXIT(zfsvfs); - - return (0); -} - -/* ARGSUSED */ -static int -zfsctl_snapdir_reclaim(ap) - struct vop_reclaim_args /* { - struct vnode *a_vp; - struct thread *a_td; - } */ *ap; -{ - vnode_t *vp = ap->a_vp; - zfsctl_snapdir_t *sdp = vp->v_data; - zfs_snapentry_t *sep; - - ASSERT(avl_numnodes(&sdp->sd_snaps) == 0); - mutex_destroy(&sdp->sd_lock); - avl_destroy(&sdp->sd_snaps); - gfs_vop_reclaim(ap); - - return (0); -} - -static int -zfsctl_shares_print(ap) - struct vop_print_args /* { - struct vnode *a_vp; - } */ *ap; -{ - printf(" .zfs/shares node\n"); - zfsctl_common_print(ap); - return (0); -} - -static int -zfsctl_snapdir_print(ap) - struct vop_print_args /* { - struct vnode *a_vp; - } */ *ap; -{ - vnode_t *vp = ap->a_vp; - zfsctl_snapdir_t *sdp = vp->v_data; + if (dsl_dataset_phys(ds)->ds_snapnames_zapobj != 0) { + err = zap_count(dmu_objset_pool(ds->ds_objset)->dp_meta_objset, + dsl_dataset_phys(ds)->ds_snapnames_zapobj, &snap_count); + if (err != 0) + return (err); + vap->va_nlink += snap_count; + } + vap->va_size = vap->va_nlink; - printf(" .zfs/snapshot node\n"); - printf(" number of children = %lu\n", avl_numnodes(&sdp->sd_snaps)); - zfsctl_common_print(ap); return (0); } -#ifdef illumos -static const fs_operation_def_t zfsctl_tops_snapdir[] = { - { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, - { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, - { VOPNAME_IOCTL, { .error = fs_inval } }, - { VOPNAME_GETATTR, { .vop_getattr = zfsctl_snapdir_getattr } }, - { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, - { VOPNAME_RENAME, { .vop_rename = zfsctl_snapdir_rename } }, - { VOPNAME_RMDIR, { .vop_rmdir = zfsctl_snapdir_remove } }, - { VOPNAME_MKDIR, { .vop_mkdir = zfsctl_snapdir_mkdir } }, - { VOPNAME_READDIR, { .vop_readdir = gfs_vop_readdir } }, - { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_snapdir_lookup } }, - { VOPNAME_SEEK, { .vop_seek = fs_seek } }, - { VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapdir_inactive } }, - { VOPNAME_FID, { .vop_fid = zfsctl_common_fid } }, - { NULL } -}; - -static const fs_operation_def_t zfsctl_tops_shares[] = { - { VOPNAME_OPEN, { .vop_open = zfsctl_common_open } }, - { VOPNAME_CLOSE, { .vop_close = zfsctl_common_close } }, - { VOPNAME_IOCTL, { .error = fs_inval } }, - { VOPNAME_GETATTR, { .vop_getattr = zfsctl_shares_getattr } }, - { VOPNAME_ACCESS, { .vop_access = zfsctl_common_access } }, - { VOPNAME_READDIR, { .vop_readdir = zfsctl_shares_readdir } }, - { VOPNAME_LOOKUP, { .vop_lookup = zfsctl_shares_lookup } }, - { VOPNAME_SEEK, { .vop_seek = fs_seek } }, - { VOPNAME_INACTIVE, { .vop_inactive = gfs_vop_inactive } }, - { VOPNAME_FID, { .vop_fid = zfsctl_shares_fid } }, - { NULL } -}; -#else /* !illumos */ static struct vop_vector zfsctl_ops_snapdir = { .vop_default = &default_vnodeops, .vop_open = zfsctl_common_open, .vop_close = zfsctl_common_close, - .vop_ioctl = VOP_EINVAL, .vop_getattr = zfsctl_snapdir_getattr, .vop_access = zfsctl_common_access, - .vop_mkdir = zfsctl_freebsd_snapdir_mkdir, - .vop_readdir = gfs_vop_readdir, + .vop_readdir = zfsctl_snapdir_readdir, .vop_lookup = zfsctl_snapdir_lookup, - .vop_inactive = VOP_NULL, - .vop_reclaim = zfsctl_snapdir_reclaim, + .vop_reclaim = zfsctl_common_reclaim, .vop_fid = zfsctl_common_fid, - .vop_print = zfsctl_snapdir_print, + .vop_print = zfsctl_common_print, }; -static struct vop_vector zfsctl_ops_shares = { - .vop_default = &default_vnodeops, - .vop_open = zfsctl_common_open, - .vop_close = zfsctl_common_close, - .vop_ioctl = VOP_EINVAL, - .vop_getattr = zfsctl_shares_getattr, - .vop_access = zfsctl_common_access, - .vop_readdir = zfsctl_shares_readdir, - .vop_lookup = zfsctl_shares_lookup, - .vop_inactive = VOP_NULL, - .vop_reclaim = gfs_vop_reclaim, - .vop_fid = zfsctl_shares_fid, - .vop_print = zfsctl_shares_print, -}; -#endif /* illumos */ - -/* - * pvp is the GFS vnode '.zfs/snapshot'. - * - * This creates a GFS node under '.zfs/snapshot' representing each - * snapshot. This newly created GFS node is what we mount snapshot - * vfs_t's ontop of. - */ -static vnode_t * -zfsctl_snapshot_mknode(vnode_t *pvp, uint64_t objset) -{ - vnode_t *vp; - zfsctl_node_t *zcp; - - vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp, pvp->v_vfsp, - &zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL); - zcp = vp->v_data; - zcp->zc_id = objset; - VOP_UNLOCK(vp, 0); - - return (vp); -} - static int zfsctl_snapshot_inactive(ap) struct vop_inactive_args /* { @@ -1518,7 +1045,7 @@ zfsctl_snapshot_inactive(ap) { vnode_t *vp = ap->a_vp; - vrecycle(vp); + VERIFY(vrecycle(vp) == 1); return (0); } @@ -1530,183 +1057,105 @@ zfsctl_snapshot_reclaim(ap) } */ *ap; { vnode_t *vp = ap->a_vp; - cred_t *cr = ap->a_td->td_ucred; - zfsctl_snapdir_t *sdp; - zfs_snapentry_t *sep, *next; - int locked; - vnode_t *dvp; - - VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0); - sdp = dvp->v_data; - /* this may already have been unmounted */ - if (sdp == NULL) { - VN_RELE(dvp); - return (0); - } - if (!(locked = MUTEX_HELD(&sdp->sd_lock))) - mutex_enter(&sdp->sd_lock); + void *data = vp->v_data; - ASSERT(!vn_ismntpt(vp)); - - sep = avl_first(&sdp->sd_snaps); - while (sep != NULL) { - next = AVL_NEXT(&sdp->sd_snaps, sep); - - if (sep->se_root == vp) { - avl_remove(&sdp->sd_snaps, sep); - kmem_free(sep->se_name, strlen(sep->se_name) + 1); - kmem_free(sep, sizeof (zfs_snapentry_t)); - break; - } - sep = next; - } - ASSERT(sep != NULL); - - if (!locked) - mutex_exit(&sdp->sd_lock); - VN_RELE(dvp); - - /* - * Dispose of the vnode for the snapshot mount point. - * This is safe to do because once this entry has been removed - * from the AVL tree, it can't be found again, so cannot become - * "active". If we lookup the same name again we will end up - * creating a new vnode. - */ - gfs_vop_reclaim(ap); + sfs_reclaim_vnode(vp); + sfs_destroy_node(data); return (0); - } static int zfsctl_snapshot_vptocnp(struct vop_vptocnp_args *ap) { - zfsvfs_t *zfsvfs = ap->a_vp->v_vfsp->vfs_data; - vnode_t *dvp, *vp; - zfsctl_snapdir_t *sdp; - zfs_snapentry_t *sep; + struct mount *mp; + vnode_t *dvp; + vnode_t *vp; + sfs_node_t *node; + size_t len; + int locked; int error; - ASSERT(zfsvfs->z_ctldir != NULL); - error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, - NULL, 0, NULL, kcred, NULL, NULL, NULL); - if (error != 0) - return (error); - sdp = dvp->v_data; + vp = ap->a_vp; + node = vp->v_data; + len = strlen(node->sn_name); + if (*ap->a_buflen < len) + return (SET_ERROR(ENOMEM)); - mutex_enter(&sdp->sd_lock); - sep = avl_first(&sdp->sd_snaps); - while (sep != NULL) { - vp = sep->se_root; - if (vp == ap->a_vp) - break; - sep = AVL_NEXT(&sdp->sd_snaps, sep); - } - if (sep == NULL) { - mutex_exit(&sdp->sd_lock); - error = SET_ERROR(ENOENT); - } else { - size_t len; - - len = strlen(sep->se_name); - if (*ap->a_buflen < len) { - mutex_exit(&sdp->sd_lock); - error = SET_ERROR(ENOMEM); - } else { - *ap->a_buflen -= len; - bcopy(sep->se_name, ap->a_buf + *ap->a_buflen, len); - mutex_exit(&sdp->sd_lock); - vref(dvp); - *ap->a_vpp = dvp; - } - } - VN_RELE(dvp); + /* + * Prevent unmounting of the snapshot while the vnode lock + * is not held. That is not strictly required, but allows + * us to assert that an uncovered snapshot vnode is never + * "leaked". + */ + mp = vp->v_mountedhere; + if (mp == NULL) + return (SET_ERROR(ENOENT)); + error = vfs_busy(mp, 0); + KASSERT(error == 0, ("vfs_busy(mp, 0) failed with %d", error)); + /* + * We can vput the vnode as we can now depend on the reference owned + * by the busied mp. But we also need to hold the vnode, because + * the reference may go after vfs_unbusy() which has to be called + * before we can lock the vnode again. + */ + locked = VOP_ISLOCKED(vp); + vhold(vp); + vput(vp); + + /* Look up .zfs/snapshot, our parent. */ + error = zfsctl_snapdir_vnode(vp->v_mount, NULL, LK_SHARED, &dvp); + if (error == 0) { + VOP_UNLOCK(dvp, 0); + *ap->a_vpp = dvp; + *ap->a_buflen -= len; + bcopy(node->sn_name, ap->a_buf + *ap->a_buflen, len); + } + vfs_unbusy(mp); + vget(vp, locked | LK_RETRY, curthread); + vdrop(vp); return (error); } -static int -zfsctl_snaphot_print(ap) - struct vop_print_args /* { - struct vnode *a_vp; - } */ *ap; -{ - vnode_t *vp = ap->a_vp; - zfsctl_node_t *zcp = vp->v_data; - - printf(" .zfs/snapshot/<snap> node\n"); - printf(" id = %ju\n", (uintmax_t)zcp->zc_id); - zfsctl_common_print(ap); - return (0); -} - /* * These VP's should never see the light of day. They should always * be covered. */ static struct vop_vector zfsctl_ops_snapshot = { - .vop_default = &default_vnodeops, - .vop_inactive = zfsctl_snapshot_inactive, - .vop_reclaim = zfsctl_snapshot_reclaim, - .vop_vptocnp = zfsctl_snapshot_vptocnp, - .vop_print = zfsctl_snaphot_print, + .vop_default = NULL, /* ensure very restricted access */ + .vop_inactive = zfsctl_snapshot_inactive, + .vop_reclaim = zfsctl_snapshot_reclaim, + .vop_vptocnp = zfsctl_snapshot_vptocnp, + .vop_lock1 = vop_stdlock, + .vop_unlock = vop_stdunlock, + .vop_islocked = vop_stdislocked, + .vop_advlockpurge = vop_stdadvlockpurge, /* called by vgone */ + .vop_print = zfsctl_common_print, }; int zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp) { + struct mount *mp; zfsvfs_t *zfsvfs = vfsp->vfs_data; - vnode_t *dvp, *vp; - zfsctl_snapdir_t *sdp; - zfsctl_node_t *zcp; - zfs_snapentry_t *sep; + vnode_t *vp; int error; ASSERT(zfsvfs->z_ctldir != NULL); - error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, - NULL, 0, NULL, kcred, NULL, NULL, NULL); - if (error != 0) - return (error); - sdp = dvp->v_data; - - mutex_enter(&sdp->sd_lock); - sep = avl_first(&sdp->sd_snaps); - while (sep != NULL) { - vp = sep->se_root; - zcp = vp->v_data; - if (zcp->zc_id == objsetid) - break; - - sep = AVL_NEXT(&sdp->sd_snaps, sep); - } - - if (sep != NULL) { - VN_HOLD(vp); + *zfsvfsp = NULL; + error = sfs_vnode_get(vfsp, LK_EXCLUSIVE, + ZFSCTL_INO_SNAPDIR, objsetid, &vp); + if (error == 0 && vp != NULL) { /* - * Return the mounted root rather than the covered mount point. - * Takes the GFS vnode at .zfs/snapshot/<snapshot objsetid> - * and returns the ZFS vnode mounted on top of the GFS node. - * This ZFS vnode is the root of the vfs for objset 'objsetid'. + * XXX Probably need to at least reference, if not busy, the mp. */ - error = traverse(&vp, LK_SHARED | LK_RETRY); - if (error == 0) { - if (vp == sep->se_root) { - VN_RELE(vp); /* release covered vp */ - error = SET_ERROR(EINVAL); - } else { - *zfsvfsp = VTOZ(vp)->z_zfsvfs; - VN_URELE(vp); /* put snapshot's root vp */ - } - } - mutex_exit(&sdp->sd_lock); - } else { - error = SET_ERROR(EINVAL); - mutex_exit(&sdp->sd_lock); + if (vp->v_mountedhere != NULL) + *zfsvfsp = vp->v_mountedhere->mnt_data; + vput(vp); } - - VN_RELE(dvp); - - return (error); + if (*zfsvfsp == NULL) + return (SET_ERROR(EINVAL)); + return (0); } /* @@ -1717,52 +1166,70 @@ zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp) int zfsctl_umount_snapshots(vfs_t *vfsp, int fflags, cred_t *cr) { + char snapname[ZFS_MAX_DATASET_NAME_LEN]; zfsvfs_t *zfsvfs = vfsp->vfs_data; + struct mount *mp; vnode_t *dvp; - zfsctl_snapdir_t *sdp; - zfs_snapentry_t *sep, *next; + vnode_t *vp; + sfs_node_t *node; + sfs_node_t *snap; + uint64_t cookie; int error; ASSERT(zfsvfs->z_ctldir != NULL); - error = zfsctl_root_lookup(zfsvfs->z_ctldir, "snapshot", &dvp, - NULL, 0, NULL, cr, NULL, NULL, NULL); - if (error != 0) - return (error); - sdp = dvp->v_data; - mutex_enter(&sdp->sd_lock); + cookie = 0; + for (;;) { + uint64_t id; + + dsl_pool_config_enter(dmu_objset_pool(zfsvfs->z_os), FTAG); + error = dmu_snapshot_list_next(zfsvfs->z_os, sizeof(snapname), + snapname, &id, &cookie, NULL); + dsl_pool_config_exit(dmu_objset_pool(zfsvfs->z_os), FTAG); + if (error != 0) { + if (error == ENOENT) + error = 0; + break; + } + + for (;;) { + error = sfs_vnode_get(vfsp, LK_EXCLUSIVE, + ZFSCTL_INO_SNAPDIR, id, &vp); + if (error != 0 || vp == NULL) + break; - sep = avl_first(&sdp->sd_snaps); - while (sep != NULL) { - next = AVL_NEXT(&sdp->sd_snaps, sep); + mp = vp->v_mountedhere; - /* - * If this snapshot is not mounted, then it must - * have just been unmounted by somebody else, and - * will be cleaned up by zfsctl_snapdir_inactive(). - */ - if (vn_ismntpt(sep->se_root)) { - error = zfsctl_unmount_snap(sep, fflags, cr); - if (error) { - avl_index_t where; - - /* - * Before reinserting snapshot to the tree, - * check if it was actually removed. For example - * when snapshot mount point is busy, we will - * have an error here, but there will be no need - * to reinsert snapshot. - */ - if (avl_find(&sdp->sd_snaps, sep, &where) == NULL) - avl_insert(&sdp->sd_snaps, sep, where); + /* + * v_mountedhere being NULL means that the + * (uncovered) vnode is in a transient state + * (mounting or unmounting), so loop until it + * settles down. + */ + if (mp != NULL) break; - } + vput(vp); } - sep = next; - } - - mutex_exit(&sdp->sd_lock); - VN_RELE(dvp); + if (error != 0) + break; + if (vp == NULL) + continue; /* no mountpoint, nothing to do */ + /* + * The mount-point vnode is kept locked to avoid spurious EBUSY + * from a concurrent umount. + * The vnode lock must have recursive locking enabled. + */ + vfs_ref(mp); + error = dounmount(mp, fflags, curthread); + KASSERT_IMPLY(error == 0, vrefcnt(vp) == 1, + ("extra references after unmount")); + vput(vp); + if (error != 0) + break; + } + KASSERT_IMPLY((fflags & MS_FORCE) != 0, error == 0, + ("force unmounting failed")); return (error); } + |