* CDDL HEADER END
*/
/*
- * Copyright 2009 Sun Microsystems, Inc. All rights reserved.
- * Use is subject to license terms.
+ *
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (C) 2011 Lawrence Livermore National Security, LLC.
+ * Produced at Lawrence Livermore National Laboratory (cf, DISCLAIMER).
+ * LLNL-CODE-403049.
+ * Rewritten for Linux by:
+ * Rohan Puri <rohan.puri15@gmail.com>
+ * Brian Behlendorf <behlendorf1@llnl.gov>
*/
/*
* ZFS control directory (a.k.a. ".zfs")
*
* This directory provides a common location for all ZFS meta-objects.
- * Currently, this is only the 'snapshot' directory, but this may expand in the
- * future. The elements are built using the GFS primitives, as the hierarchy
+ * Currently, this is only the 'snapshot' and 'shares' directory, but this may
+ * expand in the future. The elements are built dynamically, as the hierarchy
* does not actually exist on disk.
*
* For 'snapshot', we don't want to have all snapshots always mounted, because
* this would take up a huge amount of space in /etc/mnttab. We have three
* types of objects:
*
- * ctldir ------> snapshotdir -------> snapshot
+ * ctldir ------> snapshotdir -------> snapshot
* |
* |
* V
* The 'snapshot' node contains just enough information to lookup '..' and act
* as a mountpoint for the snapshot. Whenever we lookup a specific snapshot, we
* perform an automount of the underlying filesystem and return the
- * corresponding vnode.
+ * corresponding inode.
*
- * All mounts are handled automatically by the kernel, but unmounts are
- * (currently) handled from user land. The main reason is that there is no
- * reliable way to auto-unmount the filesystem when it's "no longer in use".
- * When the user unmounts a filesystem, we call zfsctl_unmount(), which
- * unmounts any snapshots within the snapshot directory.
+ * All mounts are handled automatically by an user mode helper which invokes
+ * the mount mount procedure. Unmounts are handled by allowing the mount
+ * point to expire so the kernel may automatically unmount it.
*
* The '.zfs', '.zfs/snapshot', and all directories created under
- * '.zfs/snapshot' (ie: '.zfs/snapshot/<snapname>') are all GFS nodes and
- * share the same vfs_t as the head filesystem (what '.zfs' lives under).
+ * '.zfs/snapshot' (ie: '.zfs/snapshot/<snapname>') all share the same
+ * share the same zfs_sb_t as the head filesystem (what '.zfs' lives under).
*
- * File systems mounted ontop of the GFS nodes '.zfs/snapshot/<snapname>'
- * (ie: snapshots) are ZFS nodes and have their own unique vfs_t.
- * However, vnodes within these mounted on file systems have their v_vfsp
- * fields set to the head filesystem to make NFS happy (see
- * zfsctl_snapdir_lookup()). We VFS_HOLD the head filesystem's vfs_t
- * so that it cannot be freed until all snapshots have been unmounted.
+ * File systems mounted on top of the '.zfs/snapshot/<snapname>' paths
+ * (ie: snapshots) are complete ZFS filesystems and have their own unique
+ * zfs_sb_t. However, the fsid reported by these mounts will be the same
+ * as that used by the parent zfs_sb_t to make NFS happy.
*/
-#include <fs/fs_subr.h>
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/systm.h>
+#include <sys/sysmacros.h>
+#include <sys/pathname.h>
+#include <sys/vfs.h>
+#include <sys/vfs_opreg.h>
#include <sys/zfs_ctldir.h>
#include <sys/zfs_ioctl.h>
#include <sys/zfs_vfsops.h>
-#include <sys/vfs_opreg.h>
-#include <sys/gfs.h>
+#include <sys/zfs_vnops.h>
#include <sys/stat.h>
#include <sys/dmu.h>
#include <sys/dsl_deleg.h>
#include <sys/mount.h>
-#include <sys/sunddi.h>
-
+#include <sys/zpl.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;
+/*
+ * Control Directory Tunables (.zfs)
+ */
+int zfs_expire_snapshot = ZFSCTL_EXPIRE_SNAPSHOT;
-typedef struct zfsctl_snapdir {
- zfsctl_node_t sd_node;
- kmutex_t sd_lock;
- avl_tree_t sd_snaps;
-} zfsctl_snapdir_t;
+/*
+ * Dedicated task queue for unmounting snapshots.
+ */
+static taskq_t *zfs_expire_taskq;
-typedef struct {
- char *se_name;
- vnode_t *se_root;
- avl_node_t se_node;
-} zfs_snapentry_t;
+static zfs_snapentry_t *
+zfsctl_sep_alloc(void)
+{
+ return kmem_zalloc(sizeof (zfs_snapentry_t), KM_SLEEP);
+}
-static int
+void
+zfsctl_sep_free(zfs_snapentry_t *sep)
+{
+ kmem_free(sep->se_name, MAXNAMELEN);
+ kmem_free(sep->se_path, PATH_MAX);
+ kmem_free(sep, sizeof (zfs_snapentry_t));
+}
+
+/*
+ * Attempt to expire an automounted snapshot, unmounts are attempted every
+ * 'zfs_expire_snapshot' seconds until they succeed. The work request is
+ * responsible for rescheduling itself and freeing the zfs_expire_snapshot_t.
+ */
+static void
+zfsctl_expire_snapshot(void *data)
+{
+ zfs_snapentry_t *sep = (zfs_snapentry_t *)data;
+ zfs_sb_t *zsb = ITOZSB(sep->se_inode);
+ int error;
+
+ error = zfsctl_unmount_snapshot(zsb, sep->se_name, MNT_EXPIRE);
+ if (error == EBUSY)
+ sep->se_taskqid = taskq_dispatch_delay(zfs_expire_taskq,
+ zfsctl_expire_snapshot, sep, TQ_SLEEP,
+ ddi_get_lbolt() + zfs_expire_snapshot * HZ);
+}
+
+int
snapentry_compare(const void *a, const void *b)
{
const zfs_snapentry_t *sa = a;
return (0);
}
-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[];
-
-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 *);
-
-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 }
-};
-
-/*
- * 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 }
-};
-
-/* include . and .. in the calculation */
-#define NROOT_ENTRIES ((sizeof (zfsctl_root_entries) / \
- sizeof (gfs_dirent_t)) + 1)
-
-
-/*
- * 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.
- */
-void
-zfsctl_init(void)
+boolean_t
+zfsctl_is_node(struct inode *ip)
{
- VERIFY(gfs_make_opsvec(zfsctl_opsvec) == 0);
+ return (ITOZ(ip)->z_is_ctldir);
}
-void
-zfsctl_fini(void)
+boolean_t
+zfsctl_is_snapdir(struct inode *ip)
{
- /*
- * 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;
+ return (zfsctl_is_node(ip) && (ip->i_ino <= ZFSCTL_INO_SNAPDIRS));
}
/*
- * Return the inode number associated with the 'snapshot' or
- * 'shares' directory.
+ * Allocate a new inode with the passed id and ops.
*/
-/* 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);
-
- return (zfsvfs->z_shares_dir);
+static struct inode *
+zfsctl_inode_alloc(zfs_sb_t *zsb, uint64_t id,
+ const struct file_operations *fops, const struct inode_operations *ops)
+{
+ struct timespec now = current_fs_time(zsb->z_sb);
+ struct inode *ip;
+ znode_t *zp;
+
+ ip = new_inode(zsb->z_sb);
+ if (ip == NULL)
+ return (NULL);
+
+ zp = ITOZ(ip);
+ ASSERT3P(zp->z_dirlocks, ==, NULL);
+ ASSERT3P(zp->z_acl_cached, ==, NULL);
+ ASSERT3P(zp->z_xattr_cached, ==, NULL);
+ zp->z_id = id;
+ zp->z_unlinked = 0;
+ zp->z_atime_dirty = 0;
+ zp->z_zn_prefetch = 0;
+ zp->z_moved = 0;
+ zp->z_sa_hdl = NULL;
+ zp->z_blksz = 0;
+ zp->z_seq = 0;
+ zp->z_mapcnt = 0;
+ zp->z_gen = 0;
+ zp->z_size = 0;
+ zp->z_atime[0] = 0;
+ zp->z_atime[1] = 0;
+ zp->z_links = 0;
+ zp->z_pflags = 0;
+ zp->z_uid = 0;
+ zp->z_gid = 0;
+ zp->z_mode = 0;
+ zp->z_sync_cnt = 0;
+ zp->z_is_zvol = B_FALSE;
+ zp->z_is_mapped = B_FALSE;
+ zp->z_is_ctldir = B_TRUE;
+ zp->z_is_sa = B_FALSE;
+ zp->z_is_stale = B_FALSE;
+ ip->i_ino = id;
+ ip->i_mode = (S_IFDIR | S_IRUGO | S_IXUGO);
+ ip->i_uid = 0;
+ ip->i_gid = 0;
+ ip->i_blkbits = SPA_MINBLOCKSHIFT;
+ ip->i_atime = now;
+ ip->i_mtime = now;
+ ip->i_ctime = now;
+ ip->i_fop = fops;
+ ip->i_op = ops;
+
+ if (insert_inode_locked(ip)) {
+ unlock_new_inode(ip);
+ iput(ip);
+ return (NULL);
+ }
+
+ mutex_enter(&zsb->z_znodes_lock);
+ list_insert_tail(&zsb->z_all_znodes, zp);
+ zsb->z_nr_znodes++;
+ membar_producer();
+ mutex_exit(&zsb->z_znodes_lock);
+
+ unlock_new_inode(ip);
+
+ return (ip);
}
/*
- * 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.
+ * Lookup the inode with given id, it will be allocated if needed.
*/
-void
-zfsctl_create(zfsvfs_t *zfsvfs)
+static struct inode *
+zfsctl_inode_lookup(zfs_sb_t *zsb, uint64_t id,
+ const struct file_operations *fops, const struct inode_operations *ops)
{
- vnode_t *vp, *rvp;
- zfsctl_node_t *zcp;
-
- ASSERT(zfsvfs->z_ctldir == NULL);
+ struct inode *ip = 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;
-
- VERIFY(VFS_ROOT(zfsvfs->z_vfs, &rvp) == 0);
- ZFS_TIME_DECODE(&zcp->zc_cmtime, VTOZ(rvp)->z_phys->zp_crtime);
- VN_RELE(rvp);
+ while (ip == NULL) {
+ ip = ilookup(zsb->z_sb, (unsigned long)id);
+ if (ip)
+ break;
- /*
- * 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_flag &= ~(VROOT | VNOCACHE | VNOMAP | VNOSWAP | VNOMOUNT);
+ /* May fail due to concurrent zfsctl_inode_alloc() */
+ ip = zfsctl_inode_alloc(zsb, id, fops, ops);
+ }
- zfsvfs->z_ctldir = vp;
+ return (ip);
}
/*
- * 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
+ * Free zfsctl inode specific structures, currently there are none.
*/
void
-zfsctl_destroy(zfsvfs_t *zfsvfs)
+zfsctl_inode_destroy(struct inode *ip)
{
- VN_RELE(zfsvfs->z_ctldir);
- zfsvfs->z_ctldir = NULL;
+ return;
}
/*
- * Given a root znode, retrieve the associated .zfs directory.
- * Add a hold to the vnode and return it.
+ * An inode is being evicted from the cache.
*/
-vnode_t *
-zfsctl_root(znode_t *zp)
+void
+zfsctl_inode_inactive(struct inode *ip)
{
- ASSERT(zfs_has_ctldir(zp));
- VN_HOLD(zp->z_zfsvfs->z_ctldir);
- return (zp->z_zfsvfs->z_ctldir);
+ if (zfsctl_is_snapdir(ip))
+ zfsctl_snapdir_inactive(ip);
}
/*
- * Common open routine. Disallow any write access.
+ * Create the '.zfs' directory. This directory is cached as part of the VFS
+ * structure. This results in a hold on the zfs_sb_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. All other entities
+ * under the '.zfs' directory are created dynamically as needed.
+ *
+ * Because the dynamically created '.zfs' directory entries assume the use
+ * of 64-bit inode numbers this support must be disabled on 32-bit systems.
*/
-/* ARGSUSED */
-static int
-zfsctl_common_open(vnode_t **vpp, int flags, cred_t *cr, caller_context_t *ct)
+int
+zfsctl_create(zfs_sb_t *zsb)
{
- if (flags & FWRITE)
- return (EACCES);
+#if defined(CONFIG_64BIT)
+ ASSERT(zsb->z_ctldir == NULL);
- return (0);
-}
+ zsb->z_ctldir = zfsctl_inode_alloc(zsb, ZFSCTL_INO_ROOT,
+ &zpl_fops_root, &zpl_ops_root);
+ if (zsb->z_ctldir == NULL)
+ return (ENOENT);
-/*
- * Common close routine. Nothing to do here.
- */
-/* ARGSUSED */
-static int
-zfsctl_common_close(vnode_t *vpp, int flags, int count, offset_t off,
- cred_t *cr, caller_context_t *ct)
-{
return (0);
+#else
+ return (EOPNOTSUPP);
+#endif /* CONFIG_64BIT */
}
/*
- * Common access routine. Disallow writes.
+ * Destroy the '.zfs' directory. Only called when the filesystem is unmounted.
*/
-/* ARGSUSED */
-static int
-zfsctl_common_access(vnode_t *vp, int mode, int flags, cred_t *cr,
- caller_context_t *ct)
+void
+zfsctl_destroy(zfs_sb_t *zsb)
{
- if (flags & V_ACE_MASK) {
- if (mode & ACE_ALL_WRITE_PERMS)
- return (EACCES);
- } else {
- if (mode & VWRITE)
- return (EACCES);
- }
-
- return (0);
+ iput(zsb->z_ctldir);
+ zsb->z_ctldir = NULL;
}
/*
- * Common getattr function. Fill in basic information.
+ * Given a root znode, retrieve the associated .zfs directory.
+ * Add a hold to the vnode and return it.
*/
-static void
-zfsctl_common_getattr(vnode_t *vp, vattr_t *vap)
+struct inode *
+zfsctl_root(znode_t *zp)
{
- zfsctl_node_t *zcp = vp->v_data;
- timestruc_t now;
-
- vap->va_uid = 0;
- vap->va_gid = 0;
- vap->va_rdev = 0;
- /*
- * We are a purly virtual object, so we have no
- * blocksize or allocated blocks.
- */
- vap->va_blksize = 0;
- vap->va_nblocks = 0;
- vap->va_seq = 0;
- vap->va_fsid = vp->v_vfsp->vfs_dev;
- vap->va_mode = S_IRUSR | S_IXUSR | S_IRGRP | S_IXGRP |
- S_IROTH | S_IXOTH;
- vap->va_type = VDIR;
- /*
- * We live in the now (for atime).
- */
- gethrestime(&now);
- vap->va_atime = now;
- vap->va_mtime = vap->va_ctime = zcp->zc_cmtime;
+ ASSERT(zfs_has_ctldir(zp));
+ igrab(ZTOZSB(zp)->z_ctldir);
+ return (ZTOZSB(zp)->z_ctldir);
}
/*ARGSUSED*/
-static int
-zfsctl_common_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
+int
+zfsctl_fid(struct inode *ip, fid_t *fidp)
{
- zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
- zfsctl_node_t *zcp = vp->v_data;
- uint64_t object = zcp->zc_id;
+ znode_t *zp = ITOZ(ip);
+ zfs_sb_t *zsb = ITOZSB(ip);
+ uint64_t object = zp->z_id;
zfid_short_t *zfid;
int i;
- ZFS_ENTER(zfsvfs);
+ ZFS_ENTER(zsb);
if (fidp->fid_len < SHORT_FID_LEN) {
fidp->fid_len = SHORT_FID_LEN;
- ZFS_EXIT(zfsvfs);
+ ZFS_EXIT(zsb);
return (ENOSPC);
}
for (i = 0; i < sizeof (zfid->zf_gen); i++)
zfid->zf_gen[i] = 0;
- ZFS_EXIT(zfsvfs);
+ ZFS_EXIT(zsb);
return (0);
}
-
-/*ARGSUSED*/
static int
-zfsctl_shares_fid(vnode_t *vp, fid_t *fidp, caller_context_t *ct)
+zfsctl_snapshot_zname(struct inode *ip, const char *name, int len, char *zname)
{
- zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
- znode_t *dzp;
- int error;
+ objset_t *os = ITOZSB(ip)->z_os;
- ZFS_ENTER(zfsvfs);
+ if (snapshot_namecheck(name, NULL, NULL) != 0)
+ return (EILSEQ);
- if (zfsvfs->z_shares_dir == 0) {
- ZFS_EXIT(zfsvfs);
- return (ENOTSUP);
- }
+ dmu_objset_name(os, zname);
+ if ((strlen(zname) + 1 + strlen(name)) >= len)
+ return (ENAMETOOLONG);
- if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
- error = VOP_FID(ZTOV(dzp), fidp, ct);
- VN_RELE(ZTOV(dzp));
- }
+ (void) strcat(zname, "@");
+ (void) strcat(zname, name);
- ZFS_EXIT(zfsvfs);
- return (error);
+ 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)
-/*
- * Get root directory attributes.
- */
-/* ARGSUSED */
static int
-zfsctl_root_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
- caller_context_t *ct)
+zfsctl_snapshot_zpath(struct path *path, int len, char *zpath)
{
- zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
+ char *path_buffer, *path_ptr;
+ int path_len, error = 0;
+
+ path_buffer = kmem_alloc(len, KM_SLEEP);
- ZFS_ENTER(zfsvfs);
- vap->va_nodeid = ZFSCTL_INO_ROOT;
- vap->va_nlink = vap->va_size = NROOT_ENTRIES;
+ path_ptr = d_path(path, path_buffer, len);
+ if (IS_ERR(path_ptr)) {
+ error = -PTR_ERR(path_ptr);
+ goto out;
+ }
+
+ path_len = path_buffer + len - 1 - path_ptr;
+ if (path_len > len) {
+ error = EFAULT;
+ goto out;
+ }
- zfsctl_common_getattr(vp, vap);
- ZFS_EXIT(zfsvfs);
+ memcpy(zpath, path_ptr, path_len);
+ zpath[path_len] = '\0';
+out:
+ kmem_free(path_buffer, len);
- return (0);
+ return (error);
}
/*
*/
/* 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)
-{
- zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
- int err;
-
- /*
- * No extended attributes allowed under .zfs
- */
- if (flags & LOOKUP_XATTR)
- return (EINVAL);
-
- ZFS_ENTER(zfsvfs);
-
- if (strcmp(nm, "..") == 0) {
- err = VFS_ROOT(dvp->v_vfsp, vpp);
+zfsctl_root_lookup(struct inode *dip, char *name, struct inode **ipp,
+ int flags, cred_t *cr, int *direntflags, pathname_t *realpnp)
+{
+ zfs_sb_t *zsb = ITOZSB(dip);
+ int error = 0;
+
+ ZFS_ENTER(zsb);
+
+ if (strcmp(name, "..") == 0) {
+ *ipp = dip->i_sb->s_root->d_inode;
+ } else if (strcmp(name, ZFS_SNAPDIR_NAME) == 0) {
+ *ipp = zfsctl_inode_lookup(zsb, ZFSCTL_INO_SNAPDIR,
+ &zpl_fops_snapdir, &zpl_ops_snapdir);
+ } else if (strcmp(name, ZFS_SHAREDIR_NAME) == 0) {
+ *ipp = zfsctl_inode_lookup(zsb, ZFSCTL_INO_SHARES,
+ &zpl_fops_shares, &zpl_ops_shares);
} else {
- err = gfs_vop_lookup(dvp, nm, vpp, pnp, flags, rdir,
- cr, ct, direntflags, realpnp);
+ *ipp = NULL;
}
- ZFS_EXIT(zfsvfs);
-
- return (err);
-}
-
-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);
- }
-
- return (fs_pathconf(vp, cmd, valp, cr, ct));
-}
-
-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 }
-};
+ if (*ipp == NULL)
+ error = ENOENT;
-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;
+ ZFS_EXIT(zsb);
- if (snapshot_namecheck(name, NULL, NULL) != 0)
- return (EILSEQ);
- dmu_objset_name(os, zname);
- if (strlen(zname) + 1 + strlen(name) >= len)
- return (ENAMETOOLONG);
- (void) strcat(zname, "@");
- (void) strcat(zname, name);
- return (0);
+ return (error);
}
-static int
-zfsctl_unmount_snap(zfs_snapentry_t *sep, int fflags, cred_t *cr)
+/*
+ * Lookup entry point for the 'snapshot' directory. Try to open the
+ * snapshot if it exist, creating the pseudo filesystem inode as necessary.
+ * Perform a mount of the associated dataset on top of the inode.
+ */
+/* ARGSUSED */
+int
+zfsctl_snapdir_lookup(struct inode *dip, char *name, struct inode **ipp,
+ int flags, cred_t *cr, int *direntflags, pathname_t *realpnp)
{
- vnode_t *svp = sep->se_root;
+ zfs_sb_t *zsb = ITOZSB(dip);
+ uint64_t id;
int error;
- ASSERT(vn_ismntpt(svp));
-
- /* this will be dropped by dounmount() */
- if ((error = vn_vfswlock(svp)) != 0)
- return (error);
+ ZFS_ENTER(zsb);
- VN_HOLD(svp);
- error = dounmount(vn_mountedvfs(svp), fflags, cr);
+ error = dmu_snapshot_lookup(zsb->z_os, name, &id);
if (error) {
- VN_RELE(svp);
+ ZFS_EXIT(zsb);
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_inactive(svp, cr, NULL);
+ *ipp = zfsctl_inode_lookup(zsb, ZFSCTL_INO_SNAPDIRS - id,
+ &simple_dir_operations, &simple_dir_inode_operations);
+ if (*ipp) {
+#ifdef HAVE_AUTOMOUNT
+ (*ipp)->i_flags |= S_AUTOMOUNT;
+#endif /* HAVE_AUTOMOUNT */
+ } else {
+ error = ENOENT;
+ }
- kmem_free(sep->se_name, strlen(sep->se_name) + 1);
- kmem_free(sep, sizeof (zfs_snapentry_t));
+ ZFS_EXIT(zsb);
- return (0);
+ return (error);
}
static void
-zfsctl_rename_snap(zfsctl_snapdir_t *sdp, zfs_snapentry_t *sep, const char *nm)
+zfsctl_rename_snap(zfs_sb_t *zsb, zfs_snapentry_t *sep, const char *name)
{
avl_index_t where;
- vfs_t *vfsp;
- refstr_t *pathref;
- char newpath[MAXNAMELEN];
- char *tail;
- ASSERT(MUTEX_HELD(&sdp->sd_lock));
+ ASSERT(MUTEX_HELD(&zsb->z_ctldir_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);
-
- 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);
-
- vfs_unlock(vfsp);
+ avl_remove(&zsb->z_ctldir_snaps, sep);
+ (void) strcpy(sep->se_name, name);
+ VERIFY(avl_find(&zsb->z_ctldir_snaps, sep, &where) == NULL);
+ avl_insert(&zsb->z_ctldir_snaps, sep, where);
}
+/*
+ * Renaming a directory under '.zfs/snapshot' will automatically trigger
+ * a rename of the snapshot to the new given name. The rename is confined
+ * to the '.zfs/snapshot' directory snapshots cannot be moved elsewhere.
+ */
/*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)
+int
+zfsctl_snapdir_rename(struct inode *sdip, char *sname,
+ struct inode *tdip, char *tname, cred_t *cr, int flags)
{
- zfsctl_snapdir_t *sdp = sdvp->v_data;
+ zfs_sb_t *zsb = ITOZSB(sdip);
zfs_snapentry_t search, *sep;
- zfsvfs_t *zfsvfs;
avl_index_t where;
- char from[MAXNAMELEN], to[MAXNAMELEN];
- char real[MAXNAMELEN];
- int err;
+ char *to, *from, *real;
+ int error;
+
+ ZFS_ENTER(zsb);
- zfsvfs = sdvp->v_vfsp->vfs_data;
- ZFS_ENTER(zfsvfs);
+ to = kmem_alloc(MAXNAMELEN, KM_SLEEP);
+ from = kmem_alloc(MAXNAMELEN, KM_SLEEP);
+ real = kmem_alloc(MAXNAMELEN, KM_SLEEP);
- if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
- err = dmu_snapshot_realname(zfsvfs->z_os, snm, real,
+ if (zsb->z_case == ZFS_CASE_INSENSITIVE) {
+ error = dmu_snapshot_realname(zsb->z_os, sname, real,
MAXNAMELEN, NULL);
- if (err == 0) {
- snm = real;
- } else if (err != ENOTSUP) {
- ZFS_EXIT(zfsvfs);
- return (err);
+ if (error == 0) {
+ sname = real;
+ } else if (error != ENOTSUP) {
+ goto out;
}
}
- ZFS_EXIT(zfsvfs);
-
- err = zfsctl_snapshot_zname(sdvp, snm, MAXNAMELEN, from);
- if (!err)
- err = zfsctl_snapshot_zname(tdvp, tnm, MAXNAMELEN, to);
- if (!err)
- err = zfs_secpolicy_rename_perms(from, to, cr);
- if (err)
- return (err);
+ error = zfsctl_snapshot_zname(sdip, sname, MAXNAMELEN, from);
+ if (!error)
+ error = zfsctl_snapshot_zname(tdip, tname, MAXNAMELEN, to);
+ if (!error)
+ error = zfs_secpolicy_rename_perms(from, to, cr);
+ if (error)
+ goto out;
/*
* Cannot move snapshots out of the snapdir.
*/
- if (sdvp != tdvp)
- return (EINVAL);
+ if (sdip != tdip) {
+ error = EINVAL;
+ goto out;
+ }
- if (strcmp(snm, tnm) == 0)
- return (0);
+ /*
+ * No-op when names are identical.
+ */
+ if (strcmp(sname, tname) == 0) {
+ error = 0;
+ goto out;
+ }
- mutex_enter(&sdp->sd_lock);
+ mutex_enter(&zsb->z_ctldir_lock);
- search.se_name = (char *)snm;
- if ((sep = avl_find(&sdp->sd_snaps, &search, &where)) == NULL) {
- mutex_exit(&sdp->sd_lock);
- return (ENOENT);
- }
+ error = dmu_objset_rename(from, to, B_FALSE);
+ if (error)
+ goto out_unlock;
- err = dmu_objset_rename(from, to, B_FALSE);
- if (err == 0)
- zfsctl_rename_snap(sdp, sep, tnm);
+ search.se_name = (char *)sname;
+ sep = avl_find(&zsb->z_ctldir_snaps, &search, &where);
+ if (sep)
+ zfsctl_rename_snap(zsb, sep, tname);
- mutex_exit(&sdp->sd_lock);
+out_unlock:
+ mutex_exit(&zsb->z_ctldir_lock);
+out:
+ kmem_free(from, MAXNAMELEN);
+ kmem_free(to, MAXNAMELEN);
+ kmem_free(real, MAXNAMELEN);
- return (err);
+ ZFS_EXIT(zsb);
+
+ return (error);
}
+/*
+ * Removing a directory under '.zfs/snapshot' will automatically trigger
+ * the removal of the snapshot with the given name.
+ */
/* ARGSUSED */
-static int
-zfsctl_snapdir_remove(vnode_t *dvp, char *name, vnode_t *cwd, cred_t *cr,
- caller_context_t *ct, int flags)
+int
+zfsctl_snapdir_remove(struct inode *dip, char *name, cred_t *cr, int flags)
{
- zfsctl_snapdir_t *sdp = dvp->v_data;
- zfs_snapentry_t *sep;
- zfs_snapentry_t search;
- zfsvfs_t *zfsvfs;
- char snapname[MAXNAMELEN];
- char real[MAXNAMELEN];
- int err;
+ zfs_sb_t *zsb = ITOZSB(dip);
+ char *snapname, *real;
+ int error;
- zfsvfs = dvp->v_vfsp->vfs_data;
- ZFS_ENTER(zfsvfs);
+ ZFS_ENTER(zsb);
- if ((flags & FIGNORECASE) || zfsvfs->z_case == ZFS_CASE_INSENSITIVE) {
+ snapname = kmem_alloc(MAXNAMELEN, KM_SLEEP);
+ real = kmem_alloc(MAXNAMELEN, KM_SLEEP);
- err = dmu_snapshot_realname(zfsvfs->z_os, name, real,
+ if (zsb->z_case == ZFS_CASE_INSENSITIVE) {
+ error = dmu_snapshot_realname(zsb->z_os, name, real,
MAXNAMELEN, NULL);
- if (err == 0) {
+ if (error == 0) {
name = real;
- } else if (err != ENOTSUP) {
- ZFS_EXIT(zfsvfs);
- return (err);
+ } else if (error != ENOTSUP) {
+ goto out;
}
}
- ZFS_EXIT(zfsvfs);
-
- err = zfsctl_snapshot_zname(dvp, name, MAXNAMELEN, snapname);
- if (!err)
- err = zfs_secpolicy_destroy_perms(snapname, cr);
- if (err)
- return (err);
-
- mutex_enter(&sdp->sd_lock);
+ error = zfsctl_snapshot_zname(dip, name, MAXNAMELEN, snapname);
+ if (!error)
+ error = zfs_secpolicy_destroy_perms(snapname, cr);
+ if (error)
+ goto out;
- 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)
- avl_add(&sdp->sd_snaps, sep);
- else
- err = dmu_objset_destroy(snapname, B_FALSE);
- } else {
- err = ENOENT;
- }
+ error = zfsctl_unmount_snapshot(zsb, name, MNT_FORCE);
+ if ((error == 0) || (error == ENOENT))
+ error = dmu_objset_destroy(snapname, B_FALSE);
+out:
+ kmem_free(snapname, MAXNAMELEN);
+ kmem_free(real, MAXNAMELEN);
- mutex_exit(&sdp->sd_lock);
+ ZFS_EXIT(zsb);
- return (err);
+ return (error);
}
/*
- * This creates a snapshot under '.zfs/snapshot'.
+ * Creating a directory under '.zfs/snapshot' will automatically trigger
+ * the creation of a new snapshot with the given name.
*/
/* 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)
+int
+zfsctl_snapdir_mkdir(struct inode *dip, char *dirname, vattr_t *vap,
+ struct inode **ipp, cred_t *cr, int flags)
{
- zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
- char name[MAXNAMELEN];
- int err;
- static enum symfollow follow = NO_FOLLOW;
- static enum uio_seg seg = UIO_SYSSPACE;
+ zfs_sb_t *zsb = ITOZSB(dip);
+ char *dsname;
+ int error;
- if (snapshot_namecheck(dirname, NULL, NULL) != 0)
- return (EILSEQ);
+ dsname = kmem_alloc(MAXNAMELEN, KM_SLEEP);
- dmu_objset_name(zfsvfs->z_os, name);
+ if (snapshot_namecheck(dirname, NULL, NULL) != 0) {
+ error = EILSEQ;
+ goto out;
+ }
+
+ dmu_objset_name(zsb->z_os, dsname);
- *vpp = NULL;
+ error = zfs_secpolicy_snapshot_perms(dsname, cr);
+ if (error)
+ goto out;
- err = zfs_secpolicy_snapshot_perms(name, cr);
- if (err)
- return (err);
+ if (error == 0) {
+ error = dmu_objset_snapshot(dsname, dirname,
+ NULL, NULL, B_FALSE, B_FALSE, -1);
+ if (error)
+ goto out;
- if (err == 0) {
- err = dmu_objset_snapshot(name, dirname, NULL, B_FALSE);
- if (err)
- return (err);
- err = lookupnameat(dirname, seg, follow, NULL, vpp, dvp);
+ error = zfsctl_snapdir_lookup(dip, dirname, ipp,
+ 0, cr, NULL, NULL);
}
+out:
+ kmem_free(dsname, MAXNAMELEN);
- return (err);
+ return (error);
}
/*
- * Lookup entry point for the 'snapshot' directory. Try to open the
- * snapshot if it exist, creating the pseudo filesystem vnode as necessary.
- * Perform a mount of the associated dataset on top of the vnode.
+ * When a .zfs/snapshot/<snapshot> inode is evicted they must be removed
+ * from the snapshot list. This will normally happen as part of the auto
+ * unmount, however in the case of a manual snapshot unmount this will be
+ * the only notification we receive.
*/
-/* ARGSUSED */
-static int
-zfsctl_snapdir_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)
+void
+zfsctl_snapdir_inactive(struct inode *ip)
{
- zfsctl_snapdir_t *sdp = dvp->v_data;
- objset_t *snap;
- char snapname[MAXNAMELEN];
- char real[MAXNAMELEN];
- char *mountpoint;
- zfs_snapentry_t *sep, search;
- struct mounta margs;
- vfs_t *vfsp;
- size_t mountpoint_len;
- avl_index_t where;
- zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
- int err;
-
- /*
- * No extended attributes allowed under .zfs
- */
- if (flags & LOOKUP_XATTR)
- return (EINVAL);
-
- ASSERT(dvp->v_type == VDIR);
-
- /*
- * 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))
- return (ENOENT);
-
- ZFS_ENTER(zfsvfs);
-
- if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
- ZFS_EXIT(zfsvfs);
- return (0);
- }
+ zfs_sb_t *zsb = ITOZSB(ip);
+ zfs_snapentry_t *sep, *next;
- if (flags & FIGNORECASE) {
- boolean_t conflict = B_FALSE;
+ mutex_enter(&zsb->z_ctldir_lock);
- err = dmu_snapshot_realname(zfsvfs->z_os, nm, real,
- MAXNAMELEN, &conflict);
- if (err == 0) {
- nm = real;
- } else if (err != ENOTSUP) {
- ZFS_EXIT(zfsvfs);
- return (err);
- }
- if (realpnp)
- (void) strlcpy(realpnp->pn_buf, nm,
- realpnp->pn_bufsize);
- if (conflict && direntflags)
- *direntflags = ED_CASE_CONFLICT;
- }
+ sep = avl_first(&zsb->z_ctldir_snaps);
+ while (sep != NULL) {
+ next = AVL_NEXT(&zsb->z_ctldir_snaps, sep);
- 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);
- if (err) {
- VN_RELE(*vpp);
- *vpp = NULL;
- } else if (*vpp == sep->se_root) {
- /*
- * The snapshot was unmounted behind our backs,
- * try to remount it.
- */
- goto domount;
- } else {
- /*
- * VROOT was set during the traverse call. We need
- * to clear it since we're pretending to be part
- * of our parent's vfs.
- */
- (*vpp)->v_flag &= ~VROOT;
+ if (sep->se_inode == ip) {
+ avl_remove(&zsb->z_ctldir_snaps, sep);
+ taskq_cancel_id(zfs_expire_taskq, sep->se_taskqid);
+ zfsctl_sep_free(sep);
+ break;
}
- mutex_exit(&sdp->sd_lock);
- ZFS_EXIT(zfsvfs);
- return (err);
- }
-
- /*
- * The requested snapshot is not currently mounted, look it up.
- */
- err = zfsctl_snapshot_zname(dvp, nm, MAXNAMELEN, snapname);
- if (err) {
- 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
- */
- return (err == EILSEQ ? ENOENT : err);
- }
- if (dmu_objset_open(snapname, DMU_OST_ZFS,
- DS_MODE_USER | DS_MODE_READONLY, &snap) != 0) {
- mutex_exit(&sdp->sd_lock);
- ZFS_EXIT(zfsvfs);
- return (ENOENT);
- }
-
- 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);
-
- dmu_objset_close(snap);
-domount:
- mountpoint_len = strlen(refstr_value(dvp->v_vfsp->vfs_mntpt)) +
- strlen("/.zfs/snapshot/") + strlen(nm) + 1;
- mountpoint = kmem_alloc(mountpoint_len, KM_SLEEP);
- (void) snprintf(mountpoint, mountpoint_len, "%s/.zfs/snapshot/%s",
- refstr_value(dvp->v_vfsp->vfs_mntpt), nm);
-
- margs.spec = snapname;
- margs.dir = mountpoint;
- margs.flags = MS_SYSSPACE | MS_NOMNTTAB;
- margs.fstype = "zfs";
- margs.dataptr = NULL;
- margs.datalen = 0;
- margs.optptr = NULL;
- margs.optlen = 0;
-
- err = domount("zfs", &margs, *vpp, kcred, &vfsp);
- kmem_free(mountpoint, mountpoint_len);
-
- if (err == 0) {
- /*
- * Return the mounted root rather than the covered mount point.
- * Takes the GFS vnode at .zfs/snapshot/<snapname> and returns
- * the ZFS vnode mounted on top of the GFS node. This ZFS
- * vnode is the root of the newly created vfsp.
- */
- VFS_RELE(vfsp);
- err = traverse(vpp);
- }
-
- if (err == 0) {
- /*
- * Fix up the root vnode mounted on .zfs/snapshot/<snapname>.
- *
- * This is where we lie about our v_vfsp in order to
- * make .zfs/snapshot/<snapname> accessible over NFS
- * without requiring manual mounts of <snapname>.
- */
- ASSERT(VTOZ(*vpp)->z_zfsvfs != zfsvfs);
- VTOZ(*vpp)->z_zfsvfs->z_parent = zfsvfs;
- (*vpp)->v_vfsp = zfsvfs->z_vfs;
- (*vpp)->v_flag &= ~VROOT;
+ sep = next;
}
- mutex_exit(&sdp->sd_lock);
- ZFS_EXIT(zfsvfs);
- /*
- * If we had an error, drop our hold on the vnode and
- * zfsctl_snapshot_inactive() will clean up.
- */
- if (err) {
- VN_RELE(*vpp);
- *vpp = NULL;
- }
- return (err);
+ mutex_exit(&zsb->z_ctldir_lock);
}
-/* ARGSUSED */
+/*
+ * Attempt to unmount a snapshot by making a call to user space.
+ * There is no assurance that this can or will succeed, is just a
+ * best effort. In the case where it does fail, perhaps because
+ * it's in use, the unmount will fail harmlessly.
+ */
+#define SET_UNMOUNT_CMD \
+ "exec 0</dev/null " \
+ " 1>/dev/null " \
+ " 2>/dev/null; " \
+ "umount -t zfs -n %s'%s'"
+
static int
-zfsctl_shares_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_unmount_snapshot(zfs_snapentry_t *sep, int flags)
{
- zfsvfs_t *zfsvfs = dvp->v_vfsp->vfs_data;
- znode_t *dzp;
+ char *argv[] = { "/bin/sh", "-c", NULL, NULL };
+ char *envp[] = { NULL };
int error;
- ZFS_ENTER(zfsvfs);
+ argv[2] = kmem_asprintf(SET_UNMOUNT_CMD,
+ flags & MNT_FORCE ? "-f " : "", sep->se_path);
+ error = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+ strfree(argv[2]);
- if (gfs_lookup_dot(vpp, dvp, zfsvfs->z_ctldir, nm) == 0) {
- ZFS_EXIT(zfsvfs);
- return (0);
- }
+ /*
+ * The umount system utility will return 256 on error. We must
+ * assume this error is because the file system is busy so it is
+ * converted to the more sensible EBUSY.
+ */
+ if (error)
+ error = EBUSY;
- if (zfsvfs->z_shares_dir == 0) {
- ZFS_EXIT(zfsvfs);
- return (ENOTSUP);
- }
- if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0)
- error = VOP_LOOKUP(ZTOV(dzp), nm, vpp, pnp,
- flags, rdir, cr, ct, direntflags, realpnp);
+ /*
+ * This was the result of a manual unmount, cancel the delayed work
+ * to prevent zfsctl_expire_snapshot() from attempting a unmount.
+ */
+ if ((error == 0) && !(flags & MNT_EXPIRE))
+ taskq_cancel_id(zfs_expire_taskq, sep->se_taskqid);
- 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)
+int
+zfsctl_unmount_snapshot(zfs_sb_t *zsb, char *name, int flags)
{
- zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
- char snapname[MAXNAMELEN];
- uint64_t id, cookie;
- boolean_t case_conflict;
- int error;
-
- ZFS_ENTER(zfsvfs);
-
- cookie = *offp;
- error = dmu_snapshot_list_next(zfsvfs->z_os, MAXNAMELEN, snapname, &id,
- &cookie, &case_conflict);
- 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_snapentry_t search;
+ zfs_snapentry_t *sep;
+ int error = 0;
- ZFS_EXIT(zfsvfs);
+ mutex_enter(&zsb->z_ctldir_lock);
- return (0);
-}
-
-/* ARGSUSED */
-static int
-zfsctl_shares_readdir(vnode_t *vp, uio_t *uiop, cred_t *cr, int *eofp,
- caller_context_t *ct, int flags)
-{
- zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
- znode_t *dzp;
- int error;
+ search.se_name = name;
+ sep = avl_find(&zsb->z_ctldir_snaps, &search, NULL);
+ if (sep) {
+ avl_remove(&zsb->z_ctldir_snaps, sep);
+ mutex_exit(&zsb->z_ctldir_lock);
- ZFS_ENTER(zfsvfs);
+ error = __zfsctl_unmount_snapshot(sep, flags);
- if (zfsvfs->z_shares_dir == 0) {
- ZFS_EXIT(zfsvfs);
- return (ENOTSUP);
- }
- if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
- error = VOP_READDIR(ZTOV(dzp), uiop, cr, eofp, ct, flags);
- VN_RELE(ZTOV(dzp));
+ mutex_enter(&zsb->z_ctldir_lock);
+ if (error == EBUSY)
+ avl_add(&zsb->z_ctldir_snaps, sep);
+ else
+ zfsctl_sep_free(sep);
} else {
- *eofp = 1;
error = ENOENT;
}
- ZFS_EXIT(zfsvfs);
+ mutex_exit(&zsb->z_ctldir_lock);
+ ASSERT3S(error, >=, 0);
+
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".
+ * Traverse all mounted snapshots and attempt to unmount them. This
+ * is best effort, on failure EEXIST is returned and count will be set
+ * to the number of file snapshots which could not be unmounted.
*/
-vnode_t *
-zfsctl_mknode_snapdir(vnode_t *pvp)
+int
+zfsctl_unmount_snapshots(zfs_sb_t *zsb, int flags, int *count)
{
- vnode_t *vp;
- zfsctl_snapdir_t *sdp;
-
- vp = gfs_dir_create(sizeof (zfsctl_snapdir_t), pvp,
- 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));
- return (vp);
-}
+ zfs_snapentry_t *sep, *next;
+ int error = 0;
-vnode_t *
-zfsctl_mknode_shares(vnode_t *pvp)
-{
- vnode_t *vp;
- zfsctl_node_t *sdp;
+ *count = 0;
- vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp,
- zfsctl_ops_shares, NULL, NULL, MAXNAMELEN,
- NULL, NULL);
- sdp = vp->v_data;
- sdp->zc_cmtime = ((zfsctl_node_t *)pvp->v_data)->zc_cmtime;
- return (vp);
+ ASSERT(zsb->z_ctldir != NULL);
+ mutex_enter(&zsb->z_ctldir_lock);
-}
+ sep = avl_first(&zsb->z_ctldir_snaps);
+ while (sep != NULL) {
+ next = AVL_NEXT(&zsb->z_ctldir_snaps, sep);
+ avl_remove(&zsb->z_ctldir_snaps, sep);
+ mutex_exit(&zsb->z_ctldir_lock);
-/* ARGSUSED */
-static int
-zfsctl_shares_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
- caller_context_t *ct)
-{
- zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
- znode_t *dzp;
- int error;
+ error = __zfsctl_unmount_snapshot(sep, flags);
- ZFS_ENTER(zfsvfs);
- if (zfsvfs->z_shares_dir == 0) {
- ZFS_EXIT(zfsvfs);
- return (ENOTSUP);
- }
- if ((error = zfs_zget(zfsvfs, zfsvfs->z_shares_dir, &dzp)) == 0) {
- error = VOP_GETATTR(ZTOV(dzp), vap, flags, cr, ct);
- VN_RELE(ZTOV(dzp));
+ mutex_enter(&zsb->z_ctldir_lock);
+ if (error == EBUSY) {
+ avl_add(&zsb->z_ctldir_snaps, sep);
+ (*count)++;
+ } else {
+ zfsctl_sep_free(sep);
+ }
+
+ sep = next;
}
- ZFS_EXIT(zfsvfs);
- return (error);
+ mutex_exit(&zsb->z_ctldir_lock);
+ return ((*count > 0) ? EEXIST : 0);
}
-/* ARGSUSED */
-static int
-zfsctl_snapdir_getattr(vnode_t *vp, vattr_t *vap, int flags, cred_t *cr,
- caller_context_t *ct)
-{
- zfsvfs_t *zfsvfs = vp->v_vfsp->vfs_data;
- zfsctl_snapdir_t *sdp = vp->v_data;
-
- 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;
- ZFS_EXIT(zfsvfs);
+#define SET_MOUNT_CMD \
+ "exec 0</dev/null " \
+ " 1>/dev/null " \
+ " 2>/dev/null; " \
+ "mount -t zfs -n '%s' '%s'"
- return (0);
-}
-
-/* ARGSUSED */
-static void
-zfsctl_snapdir_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
+int
+zfsctl_mount_snapshot(struct path *path, int flags)
{
- zfsctl_snapdir_t *sdp = vp->v_data;
- void *private;
-
- private = gfs_dir_inactive(vp);
- if (private != NULL) {
- ASSERT(avl_numnodes(&sdp->sd_snaps) == 0);
- mutex_destroy(&sdp->sd_lock);
- avl_destroy(&sdp->sd_snaps);
- kmem_free(private, sizeof (zfsctl_snapdir_t));
- }
-}
-
-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 }
-};
+ struct dentry *dentry = path->dentry;
+ struct inode *ip = dentry->d_inode;
+ zfs_sb_t *zsb = ITOZSB(ip);
+ char *full_name, *full_path;
+ zfs_snapentry_t *sep;
+ zfs_snapentry_t search;
+ char *argv[] = { "/bin/sh", "-c", NULL, NULL };
+ char *envp[] = { NULL };
+ int error;
-/*
- * 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;
+ ZFS_ENTER(zsb);
- vp = gfs_dir_create(sizeof (zfsctl_node_t), pvp,
- zfsctl_ops_snapshot, NULL, NULL, MAXNAMELEN, NULL, NULL);
- zcp = vp->v_data;
- zcp->zc_id = objset;
+ full_name = kmem_zalloc(MAXNAMELEN, KM_SLEEP);
+ full_path = kmem_zalloc(PATH_MAX, KM_SLEEP);
- return (vp);
-}
+ error = zfsctl_snapshot_zname(ip, dname(dentry), MAXNAMELEN, full_name);
+ if (error)
+ goto error;
-static void
-zfsctl_snapshot_inactive(vnode_t *vp, cred_t *cr, caller_context_t *ct)
-{
- zfsctl_snapdir_t *sdp;
- zfs_snapentry_t *sep, *next;
- vnode_t *dvp;
+ error = zfsctl_snapshot_zpath(path, PATH_MAX, full_path);
+ if (error)
+ goto error;
- VERIFY(gfs_dir_lookup(vp, "..", &dvp, cr, 0, NULL, NULL) == 0);
- sdp = dvp->v_data;
+ /*
+ * Attempt to mount the snapshot from user space. Normally this
+ * would be done using the vfs_kern_mount() function, however that
+ * function is marked GPL-only and cannot be used. On error we
+ * careful to log the real error to the console and return EISDIR
+ * to safely abort the automount. This should be very rare.
+ */
+ argv[2] = kmem_asprintf(SET_MOUNT_CMD, full_name, full_path);
+ error = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
+ strfree(argv[2]);
+ if (error) {
+ printk("ZFS: Unable to automount %s at %s: %d\n",
+ full_name, full_path, error);
+ error = EISDIR;
+ goto error;
+ }
- mutex_enter(&sdp->sd_lock);
+ mutex_enter(&zsb->z_ctldir_lock);
- if (vp->v_count > 1) {
- mutex_exit(&sdp->sd_lock);
- return;
+ /*
+ * Ensure a previous entry does not exist, if it does safely remove
+ * it any cancel the outstanding expiration. This can occur when a
+ * snapshot is manually unmounted and then an automount is triggered.
+ */
+ search.se_name = full_name;
+ sep = avl_find(&zsb->z_ctldir_snaps, &search, NULL);
+ if (sep) {
+ avl_remove(&zsb->z_ctldir_snaps, sep);
+ taskq_cancel_id(zfs_expire_taskq, sep->se_taskqid);
+ zfsctl_sep_free(sep);
}
- ASSERT(!vn_ismntpt(vp));
- sep = avl_first(&sdp->sd_snaps);
- while (sep != NULL) {
- next = AVL_NEXT(&sdp->sd_snaps, sep);
+ sep = zfsctl_sep_alloc();
+ sep->se_name = full_name;
+ sep->se_path = full_path;
+ sep->se_inode = ip;
+ avl_add(&zsb->z_ctldir_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;
+ sep->se_taskqid = taskq_dispatch_delay(zfs_expire_taskq,
+ zfsctl_expire_snapshot, sep, TQ_SLEEP,
+ ddi_get_lbolt() + zfs_expire_snapshot * HZ);
+
+ mutex_exit(&zsb->z_ctldir_lock);
+error:
+ if (error) {
+ kmem_free(full_name, MAXNAMELEN);
+ kmem_free(full_path, PATH_MAX);
}
- ASSERT(sep != NULL);
- mutex_exit(&sdp->sd_lock);
- VN_RELE(dvp);
+ ZFS_EXIT(zsb);
- /*
- * 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_inactive(vp, cr, ct);
+ return (error);
}
+/*
+ * Check if this super block has a matching objset id.
+ */
+static int
+zfsctl_test_super(struct super_block *sb, void *objsetidp)
+{
+ zfs_sb_t *zsb = sb->s_fs_info;
+ uint64_t objsetid = *(uint64_t *)objsetidp;
+
+ return (dmu_objset_id(zsb->z_os) == objsetid);
+}
/*
- * These VP's should never see the light of day. They should always
- * be covered.
+ * Prevent a new super block from being allocated if an existing one
+ * could not be located. We only want to preform a lookup operation.
*/
-static const fs_operation_def_t zfsctl_tops_snapshot[] = {
- VOPNAME_INACTIVE, { .vop_inactive = zfsctl_snapshot_inactive },
- NULL, NULL
-};
+static int
+zfsctl_set_super(struct super_block *sb, void *objsetidp)
+{
+ return (-EEXIST);
+}
int
-zfsctl_lookup_objset(vfs_t *vfsp, uint64_t objsetid, zfsvfs_t **zfsvfsp)
+zfsctl_lookup_objset(struct super_block *sb, uint64_t objsetid, zfs_sb_t **zsbp)
{
- zfsvfs_t *zfsvfs = vfsp->vfs_data;
- vnode_t *dvp, *vp;
- zfsctl_snapdir_t *sdp;
- zfsctl_node_t *zcp;
+ zfs_sb_t *zsb = sb->s_fs_info;
+ struct super_block *sbp;
zfs_snapentry_t *sep;
+ uint64_t id;
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;
+ ASSERT(zsb->z_ctldir != NULL);
+
+ mutex_enter(&zsb->z_ctldir_lock);
- mutex_enter(&sdp->sd_lock);
- sep = avl_first(&sdp->sd_snaps);
+ /*
+ * Verify that the snapshot is mounted.
+ */
+ sep = avl_first(&zsb->z_ctldir_snaps);
while (sep != NULL) {
- vp = sep->se_root;
- zcp = vp->v_data;
- if (zcp->zc_id == objsetid)
+ error = dmu_snapshot_lookup(zsb->z_os, sep->se_name, &id);
+ if (error)
+ goto out;
+
+ if (id == objsetid)
break;
- sep = AVL_NEXT(&sdp->sd_snaps, sep);
+ sep = AVL_NEXT(&zsb->z_ctldir_snaps, sep);
}
if (sep != NULL) {
- VN_HOLD(vp);
/*
- * 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'.
+ * Lookup the mounted root rather than the covered mount
+ * point. This may fail if the snapshot has just been
+ * unmounted by an unrelated user space process. This
+ * race cannot occur to an expired mount point because
+ * we hold the zsb->z_ctldir_lock to prevent the race.
*/
- error = traverse(&vp);
- if (error == 0) {
- if (vp == sep->se_root)
- error = EINVAL;
- else
- *zfsvfsp = VTOZ(vp)->z_zfsvfs;
+ sbp = zpl_sget(&zpl_fs_type, zfsctl_test_super,
+ zfsctl_set_super, 0, &id);
+ if (IS_ERR(sbp)) {
+ error = -PTR_ERR(sbp);
+ } else {
+ *zsbp = sbp->s_fs_info;
+ deactivate_super(sbp);
}
- mutex_exit(&sdp->sd_lock);
- VN_RELE(vp);
} else {
error = EINVAL;
- mutex_exit(&sdp->sd_lock);
}
-
- VN_RELE(dvp);
+out:
+ mutex_exit(&zsb->z_ctldir_lock);
+ ASSERT3S(error, >=, 0);
return (error);
}
-/*
- * Unmount any snapshots for the given filesystem. This is called from
- * zfs_umount() - if we have a ctldir, then go through and unmount all the
- * snapshots.
- */
+/* ARGSUSED */
int
-zfsctl_umount_snapshots(vfs_t *vfsp, int fflags, cred_t *cr)
+zfsctl_shares_lookup(struct inode *dip, char *name, struct inode **ipp,
+ int flags, cred_t *cr, int *direntflags, pathname_t *realpnp)
{
- zfsvfs_t *zfsvfs = vfsp->vfs_data;
- vnode_t *dvp;
- zfsctl_snapdir_t *sdp;
- zfs_snapentry_t *sep, *next;
+ zfs_sb_t *zsb = ITOZSB(dip);
+ struct inode *ip;
+ znode_t *dzp;
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);
+ ZFS_ENTER(zsb);
- sep = avl_first(&sdp->sd_snaps);
- while (sep != NULL) {
- next = AVL_NEXT(&sdp->sd_snaps, sep);
+ if (zsb->z_shares_dir == 0) {
+ ZFS_EXIT(zsb);
+ return (ENOTSUP);
+ }
- /*
- * 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)) {
- avl_remove(&sdp->sd_snaps, sep);
- error = zfsctl_unmount_snap(sep, fflags, cr);
- if (error) {
- avl_add(&sdp->sd_snaps, sep);
- break;
- }
- }
- sep = next;
+ error = zfs_zget(zsb, zsb->z_shares_dir, &dzp);
+ if (error) {
+ ZFS_EXIT(zsb);
+ return (error);
}
- mutex_exit(&sdp->sd_lock);
- VN_RELE(dvp);
+ error = zfs_lookup(ZTOI(dzp), name, &ip, 0, cr, NULL, NULL);
+
+ iput(ZTOI(dzp));
+ ZFS_EXIT(zsb);
return (error);
}
+
+
+/*
+ * Initialize the various pieces we'll need to create and manipulate .zfs
+ * directories. Currently this is unused but available.
+ */
+void
+zfsctl_init(void)
+{
+ zfs_expire_taskq = taskq_create("z_unmount", 1, maxclsyspri,
+ 1, 8, TASKQ_PREPOPULATE);
+}
+
+/*
+ * Cleanup the various pieces we needed for .zfs directories. In particular
+ * ensure the expiry timer is canceled safely.
+ */
+void
+zfsctl_fini(void)
+{
+ taskq_destroy(zfs_expire_taskq);
+}
+
+module_param(zfs_expire_snapshot, int, 0644);
+MODULE_PARM_DESC(zfs_expire_snapshot, "Seconds to expire .zfs/snapshot");
git://git.camperquake.de / zfs.git / blobdiff