[mirror_zfs.git] / module / zfs / zpl_super.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright (c) 2011, Lawrence Livermore National Security, LLC.
 */


#include <sys/zfs_vfsops.h>
#include <sys/zfs_vnops.h>
#include <sys/zfs_znode.h>
#include <sys/zfs_ctldir.h>
#include <sys/zpl.h>


static struct inode *
zpl_inode_alloc(struct super_block *sb)
{
	struct inode *ip;

	VERIFY3S(zfs_inode_alloc(sb, &ip), ==, 0);
	inode_set_iversion(ip, 1);

	return (ip);
}

static void
zpl_inode_destroy(struct inode *ip)
{
	ASSERT(atomic_read(&ip->i_count) == 0);
	zfs_inode_destroy(ip);
}

/*
 * Called from __mark_inode_dirty() to reflect that something in the
 * inode has changed.  We use it to ensure the znode system attributes
 * are always strictly update to date with respect to the inode.
 */
#ifdef HAVE_DIRTY_INODE_WITH_FLAGS
static void
zpl_dirty_inode(struct inode *ip, int flags)
{
	fstrans_cookie_t cookie;

	cookie = spl_fstrans_mark();
	zfs_dirty_inode(ip, flags);
	spl_fstrans_unmark(cookie);
}
#else
static void
zpl_dirty_inode(struct inode *ip)
{
	fstrans_cookie_t cookie;

	cookie = spl_fstrans_mark();
	zfs_dirty_inode(ip, 0);
	spl_fstrans_unmark(cookie);
}
#endif /* HAVE_DIRTY_INODE_WITH_FLAGS */

/*
 * When ->drop_inode() is called its return value indicates if the
 * inode should be evicted from the inode cache.  If the inode is
 * unhashed and has no links the default policy is to evict it
 * immediately.
 *
 * Prior to 2.6.36 this eviction was accomplished by the vfs calling
 * ->delete_inode().  It was ->delete_inode()'s responsibility to
 * truncate the inode pages and call clear_inode().  The call to
 * clear_inode() synchronously invalidates all the buffers and
 * calls ->clear_inode().  It was ->clear_inode()'s responsibility
 * to cleanup and filesystem specific data before freeing the inode.
 *
 * This elaborate mechanism was replaced by ->evict_inode() which
 * does the job of both ->delete_inode() and ->clear_inode().  It
 * will be called exactly once, and when it returns the inode must
 * be in a state where it can simply be freed.i
 *
 * The ->evict_inode() callback must minimally truncate the inode pages,
 * and call clear_inode().  For 2.6.35 and later kernels this will
 * simply update the inode state, with the sync occurring before the
 * truncate in evict().  For earlier kernels clear_inode() maps to
 * end_writeback() which is responsible for completing all outstanding
 * write back.  In either case, once this is done it is safe to cleanup
 * any remaining inode specific data via zfs_inactive().
 * remaining filesystem specific data.
 */
#ifdef HAVE_EVICT_INODE
static void
zpl_evict_inode(struct inode *ip)
{
	fstrans_cookie_t cookie;

	cookie = spl_fstrans_mark();
	truncate_setsize(ip, 0);
	clear_inode(ip);
	zfs_inactive(ip);
	spl_fstrans_unmark(cookie);
}

#else

static void
zpl_drop_inode(struct inode *ip)
{
	generic_delete_inode(ip);
}

static void
zpl_clear_inode(struct inode *ip)
{
	fstrans_cookie_t cookie;

	cookie = spl_fstrans_mark();
	zfs_inactive(ip);
	spl_fstrans_unmark(cookie);
}

static void
zpl_inode_delete(struct inode *ip)
{
	truncate_setsize(ip, 0);
	clear_inode(ip);
}
#endif /* HAVE_EVICT_INODE */

static void
zpl_put_super(struct super_block *sb)
{
	fstrans_cookie_t cookie;
	int error;

	cookie = spl_fstrans_mark();
	error = -zfs_umount(sb);
	spl_fstrans_unmark(cookie);
	ASSERT3S(error, <=, 0);
}

static int
zpl_sync_fs(struct super_block *sb, int wait)
{
	fstrans_cookie_t cookie;
	cred_t *cr = CRED();
	int error;

	crhold(cr);
	cookie = spl_fstrans_mark();
	error = -zfs_sync(sb, wait, cr);
	spl_fstrans_unmark(cookie);
	crfree(cr);
	ASSERT3S(error, <=, 0);

	return (error);
}

static int
zpl_statfs(struct dentry *dentry, struct kstatfs *statp)
{
	fstrans_cookie_t cookie;
	int error;

	cookie = spl_fstrans_mark();
	error = -zfs_statvfs(dentry, statp);
	spl_fstrans_unmark(cookie);
	ASSERT3S(error, <=, 0);

	/*
	 * If required by a 32-bit system call, dynamically scale the
	 * block size up to 16MiB and decrease the block counts.  This
	 * allows for a maximum size of 64EiB to be reported.  The file
	 * counts must be artificially capped at 2^32-1.
	 */
	if (unlikely(zpl_is_32bit_api())) {
		while (statp->f_blocks > UINT32_MAX &&
		    statp->f_bsize < SPA_MAXBLOCKSIZE) {
			statp->f_frsize <<= 1;
			statp->f_bsize <<= 1;

			statp->f_blocks >>= 1;
			statp->f_bfree >>= 1;
			statp->f_bavail >>= 1;
		}

		uint64_t usedobjs = statp->f_files - statp->f_ffree;
		statp->f_ffree = MIN(statp->f_ffree, UINT32_MAX - usedobjs);
		statp->f_files = statp->f_ffree + usedobjs;
	}

	return (error);
}

static int
zpl_remount_fs(struct super_block *sb, int *flags, char *data)
{
	zfs_mnt_t zm = { .mnt_osname = NULL, .mnt_data = data };
	fstrans_cookie_t cookie;
	int error;

	cookie = spl_fstrans_mark();
	error = -zfs_remount(sb, flags, &zm);
	spl_fstrans_unmark(cookie);
	ASSERT3S(error, <=, 0);

	return (error);
}

static int
__zpl_show_options(struct seq_file *seq, zfsvfs_t *zfsvfs)
{
	seq_printf(seq, ",%s",
	    zfsvfs->z_flags & ZSB_XATTR ? "xattr" : "noxattr");

#ifdef CONFIG_FS_POSIX_ACL
	switch (zfsvfs->z_acl_type) {
	case ZFS_ACLTYPE_POSIXACL:
		seq_puts(seq, ",posixacl");
		break;
	default:
		seq_puts(seq, ",noacl");
		break;
	}
#endif /* CONFIG_FS_POSIX_ACL */

	return (0);
}

#ifdef HAVE_SHOW_OPTIONS_WITH_DENTRY
static int
zpl_show_options(struct seq_file *seq, struct dentry *root)
{
	return (__zpl_show_options(seq, root->d_sb->s_fs_info));
}
#else
static int
zpl_show_options(struct seq_file *seq, struct vfsmount *vfsp)
{
	return (__zpl_show_options(seq, vfsp->mnt_sb->s_fs_info));
}
#endif /* HAVE_SHOW_OPTIONS_WITH_DENTRY */

static int
zpl_fill_super(struct super_block *sb, void *data, int silent)
{
	zfs_mnt_t *zm = (zfs_mnt_t *)data;
	fstrans_cookie_t cookie;
	int error;

	cookie = spl_fstrans_mark();
	error = -zfs_domount(sb, zm, silent);
	spl_fstrans_unmark(cookie);
	ASSERT3S(error, <=, 0);

	return (error);
}

static int
zpl_test_super(struct super_block *s, void *data)
{
	zfsvfs_t *zfsvfs = s->s_fs_info;
	objset_t *os = data;

	if (zfsvfs == NULL)
		return (0);

	return (os == zfsvfs->z_os);
}

static struct super_block *
zpl_mount_impl(struct file_system_type *fs_type, int flags, zfs_mnt_t *zm)
{
	struct super_block *s;
	objset_t *os;
	int err;

	err = dmu_objset_hold(zm->mnt_osname, FTAG, &os);
	if (err)
		return (ERR_PTR(-err));

	/*
	 * The dsl pool lock must be released prior to calling sget().
	 * It is possible sget() may block on the lock in grab_super()
	 * while deactivate_super() holds that same lock and waits for
	 * a txg sync.  If the dsl_pool lock is held over sget()
	 * this can prevent the pool sync and cause a deadlock.
	 */
	dsl_pool_rele(dmu_objset_pool(os), FTAG);
	s = zpl_sget(fs_type, zpl_test_super, set_anon_super, flags, os);
	dsl_dataset_rele(dmu_objset_ds(os), FTAG);

	if (IS_ERR(s))
		return (ERR_CAST(s));

	if (s->s_root == NULL) {
		err = zpl_fill_super(s, zm, flags & SB_SILENT ? 1 : 0);
		if (err) {
			deactivate_locked_super(s);
			return (ERR_PTR(err));
		}
		s->s_flags |= SB_ACTIVE;
	} else if ((flags ^ s->s_flags) & SB_RDONLY) {
		deactivate_locked_super(s);
		return (ERR_PTR(-EBUSY));
	}

	return (s);
}

#ifdef HAVE_FST_MOUNT
static struct dentry *
zpl_mount(struct file_system_type *fs_type, int flags,
    const char *osname, void *data)
{
	zfs_mnt_t zm = { .mnt_osname = osname, .mnt_data = data };

	struct super_block *sb = zpl_mount_impl(fs_type, flags, &zm);
	if (IS_ERR(sb))
		return (ERR_CAST(sb));

	return (dget(sb->s_root));
}
#else
static int
zpl_get_sb(struct file_system_type *fs_type, int flags,
    const char *osname, void *data, struct vfsmount *mnt)
{
	zfs_mnt_t zm = { .mnt_osname = osname, .mnt_data = data };

	struct super_block *sb = zpl_mount_impl(fs_type, flags, &zm);
	if (IS_ERR(sb))
		return (PTR_ERR(sb));

	(void) simple_set_mnt(mnt, sb);

	return (0);
}
#endif /* HAVE_FST_MOUNT */

static void
zpl_kill_sb(struct super_block *sb)
{
	zfs_preumount(sb);
	kill_anon_super(sb);

#ifdef HAVE_S_INSTANCES_LIST_HEAD
	sb->s_instances.next = &(zpl_fs_type.fs_supers);
#endif /* HAVE_S_INSTANCES_LIST_HEAD */
}

void
zpl_prune_sb(int64_t nr_to_scan, void *arg)
{
	struct super_block *sb = (struct super_block *)arg;
	int objects = 0;

	(void) -zfs_prune(sb, nr_to_scan, &objects);
}

#ifdef HAVE_NR_CACHED_OBJECTS
static int
zpl_nr_cached_objects(struct super_block *sb)
{
	return (0);
}
#endif /* HAVE_NR_CACHED_OBJECTS */

#ifdef HAVE_FREE_CACHED_OBJECTS
static void
zpl_free_cached_objects(struct super_block *sb, int nr_to_scan)
{
	/* noop */
}
#endif /* HAVE_FREE_CACHED_OBJECTS */

const struct super_operations zpl_super_operations = {
	.alloc_inode		= zpl_inode_alloc,
	.destroy_inode		= zpl_inode_destroy,
	.dirty_inode		= zpl_dirty_inode,
	.write_inode		= NULL,
#ifdef HAVE_EVICT_INODE
	.evict_inode		= zpl_evict_inode,
#else
	.drop_inode		= zpl_drop_inode,
	.clear_inode		= zpl_clear_inode,
	.delete_inode		= zpl_inode_delete,
#endif /* HAVE_EVICT_INODE */
	.put_super		= zpl_put_super,
	.sync_fs		= zpl_sync_fs,
	.statfs			= zpl_statfs,
	.remount_fs		= zpl_remount_fs,
	.show_options		= zpl_show_options,
	.show_stats		= NULL,
#ifdef HAVE_NR_CACHED_OBJECTS
	.nr_cached_objects	= zpl_nr_cached_objects,
#endif /* HAVE_NR_CACHED_OBJECTS */
#ifdef HAVE_FREE_CACHED_OBJECTS
	.free_cached_objects	= zpl_free_cached_objects,
#endif /* HAVE_FREE_CACHED_OBJECTS */
};

struct file_system_type zpl_fs_type = {
	.owner			= THIS_MODULE,
	.name			= ZFS_DRIVER,
#ifdef HAVE_FST_MOUNT
	.mount			= zpl_mount,
#else
	.get_sb			= zpl_get_sb,
#endif /* HAVE_FST_MOUNT */
	.kill_sb		= zpl_kill_sb,
};
Commit	Line	Data
51f0bbe4 BB	1	/*
	2	* CDDL HEADER START
	3	*
	4	* The contents of this file are subject to the terms of the
	5	* Common Development and Distribution License (the "License").
	6	* You may not use this file except in compliance with the License.
	7	*
	8	* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
	9	* or http://www.opensolaris.org/os/licensing.
	10	* See the License for the specific language governing permissions
	11	* and limitations under the License.
	12	*
	13	* When distributing Covered Code, include this CDDL HEADER in each
	14	* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
	15	* If applicable, add the following below this CDDL HEADER, with the
	16	* fields enclosed by brackets "[]" replaced with your own identifying
	17	* information: Portions Copyright [yyyy] [name of copyright owner]
	18	*
	19	* CDDL HEADER END
	20	*/
	21	/*
	22	* Copyright (c) 2011, Lawrence Livermore National Security, LLC.
	23	*/
	24
	25
	26	#include <sys/zfs_vfsops.h>
	27	#include <sys/zfs_vnops.h>
	28	#include <sys/zfs_znode.h>
ebe7e575	29	#include <sys/zfs_ctldir.h>
51f0bbe4 BB	30	#include <sys/zpl.h>
	31
	32
	33	static struct inode *
	34	zpl_inode_alloc(struct super_block *sb)
	35	{
	36	struct inode *ip;
	37
	38	VERIFY3S(zfs_inode_alloc(sb, &ip), ==, 0);
18f57327	39	inode_set_iversion(ip, 1);
51f0bbe4 BB	40
	41	return (ip);
	42	}
	43
	44	static void
	45	zpl_inode_destroy(struct inode *ip)
	46	{
d1d7e268	47	ASSERT(atomic_read(&ip->i_count) == 0);
51f0bbe4 BB	48	zfs_inode_destroy(ip);
	49	}
	50
8780c539 BB	51	/*
	52	* Called from __mark_inode_dirty() to reflect that something in the
	53	* inode has changed. We use it to ensure the znode system attributes
	54	* are always strictly update to date with respect to the inode.
	55	*/
	56	#ifdef HAVE_DIRTY_INODE_WITH_FLAGS
	57	static void
	58	zpl_dirty_inode(struct inode *ip, int flags)
	59	{
a438ff0e BB	60	fstrans_cookie_t cookie;
	61
	62	cookie = spl_fstrans_mark();
8780c539	63	zfs_dirty_inode(ip, flags);
a438ff0e	64	spl_fstrans_unmark(cookie);
8780c539 BB	65	}
	66	#else
	67	static void
	68	zpl_dirty_inode(struct inode *ip)
	69	{
a438ff0e BB	70	fstrans_cookie_t cookie;
	71
	72	cookie = spl_fstrans_mark();
8780c539	73	zfs_dirty_inode(ip, 0);
a438ff0e	74	spl_fstrans_unmark(cookie);
8780c539 BB	75	}
	76	#endif /* HAVE_DIRTY_INODE_WITH_FLAGS */
	77
2c395def BB	78	/*
	79	* When ->drop_inode() is called its return value indicates if the
	80	* inode should be evicted from the inode cache. If the inode is
	81	* unhashed and has no links the default policy is to evict it
	82	* immediately.
	83	*
	84	* Prior to 2.6.36 this eviction was accomplished by the vfs calling
	85	* ->delete_inode(). It was ->delete_inode()'s responsibility to
	86	* truncate the inode pages and call clear_inode(). The call to
	87	* clear_inode() synchronously invalidates all the buffers and
	88	* calls ->clear_inode(). It was ->clear_inode()'s responsibility
	89	* to cleanup and filesystem specific data before freeing the inode.
	90	*
	91	* This elaborate mechanism was replaced by ->evict_inode() which
	92	* does the job of both ->delete_inode() and ->clear_inode(). It
	93	* will be called exactly once, and when it returns the inode must
739a1a82 RY	94	* be in a state where it can simply be freed.i
	95	*
	96	* The ->evict_inode() callback must minimally truncate the inode pages,
	97	* and call clear_inode(). For 2.6.35 and later kernels this will
	98	* simply update the inode state, with the sync occurring before the
	99	* truncate in evict(). For earlier kernels clear_inode() maps to
	100	* end_writeback() which is responsible for completing all outstanding
	101	* write back. In either case, once this is done it is safe to cleanup
	102	* any remaining inode specific data via zfs_inactive().
2c395def BB	103	* remaining filesystem specific data.
	104	*/
	105	#ifdef HAVE_EVICT_INODE
51f0bbe4	106	static void
2c395def	107	zpl_evict_inode(struct inode *ip)
51f0bbe4	108	{
7f3e4662 BB	109	fstrans_cookie_t cookie;
	110
	111	cookie = spl_fstrans_mark();
b3129792	112	truncate_setsize(ip, 0);
739a1a82	113	clear_inode(ip);
2c395def	114	zfs_inactive(ip);
7f3e4662	115	spl_fstrans_unmark(cookie);
51f0bbe4 BB	116	}
51f0bbe4 BB	117
2c395def BB	118	#else
2c395def BB	119
2cbb06b5 BB	120	static void
	121	zpl_drop_inode(struct inode *ip)
	122	{
	123	generic_delete_inode(ip);
	124	}
	125
51f0bbe4	126	static void
2c395def	127	zpl_clear_inode(struct inode *ip)
51f0bbe4	128	{
7f3e4662 BB	129	fstrans_cookie_t cookie;
	130
	131	cookie = spl_fstrans_mark();
51f0bbe4	132	zfs_inactive(ip);
7f3e4662	133	spl_fstrans_unmark(cookie);
51f0bbe4 BB	134	}
51f0bbe4 BB	135
2c395def BB	136	static void
	137	zpl_inode_delete(struct inode *ip)
	138	{
b3129792	139	truncate_setsize(ip, 0);
2c395def BB	140	clear_inode(ip);
2c395def BB	141	}
2c395def BB	142	#endif /* HAVE_EVICT_INODE */
2c395def BB	143
51f0bbe4 BB	144	static void
	145	zpl_put_super(struct super_block *sb)
	146	{
7fad6290	147	fstrans_cookie_t cookie;
51f0bbe4 BB	148	int error;
51f0bbe4 BB	149
7fad6290	150	cookie = spl_fstrans_mark();
51f0bbe4	151	error = -zfs_umount(sb);
7fad6290	152	spl_fstrans_unmark(cookie);
51f0bbe4 BB	153	ASSERT3S(error, <=, 0);
	154	}
	155
03f9ba9d BB	156	static int
	157	zpl_sync_fs(struct super_block *sb, int wait)
	158	{
7fad6290	159	fstrans_cookie_t cookie;
0d3ac5e7	160	cred_t *cr = CRED();
03f9ba9d BB	161	int error;
03f9ba9d BB	162
0d3ac5e7	163	crhold(cr);
7fad6290	164	cookie = spl_fstrans_mark();
03f9ba9d	165	error = -zfs_sync(sb, wait, cr);
7fad6290	166	spl_fstrans_unmark(cookie);
0d3ac5e7	167	crfree(cr);
03f9ba9d BB	168	ASSERT3S(error, <=, 0);
	169
	170	return (error);
	171	}
	172
51f0bbe4 BB	173	static int
	174	zpl_statfs(struct dentry dentry, struct kstatfs statp)
	175	{
7fad6290	176	fstrans_cookie_t cookie;
51f0bbe4 BB	177	int error;
51f0bbe4 BB	178
7fad6290	179	cookie = spl_fstrans_mark();
51f0bbe4	180	error = -zfs_statvfs(dentry, statp);
7fad6290	181	spl_fstrans_unmark(cookie);
51f0bbe4 BB	182	ASSERT3S(error, <=, 0);
51f0bbe4 BB	183
e897a23e BB	184	/*
	185	* If required by a 32-bit system call, dynamically scale the
	186	* block size up to 16MiB and decrease the block counts. This
	187	* allows for a maximum size of 64EiB to be reported. The file
	188	* counts must be artificially capped at 2^32-1.
	189	*/
	190	if (unlikely(zpl_is_32bit_api())) {
	191	while (statp->f_blocks > UINT32_MAX &&
	192	statp->f_bsize < SPA_MAXBLOCKSIZE) {
	193	statp->f_frsize <<= 1;
	194	statp->f_bsize <<= 1;
	195
	196	statp->f_blocks >>= 1;
	197	statp->f_bfree >>= 1;
	198	statp->f_bavail >>= 1;
	199	}
	200
	201	uint64_t usedobjs = statp->f_files - statp->f_ffree;
	202	statp->f_ffree = MIN(statp->f_ffree, UINT32_MAX - usedobjs);
	203	statp->f_files = statp->f_ffree + usedobjs;
	204	}
	205
51f0bbe4 BB	206	return (error);
	207	}
	208
0de19dad BB	209	static int
	210	zpl_remount_fs(struct super_block sb, int flags, char *data)
	211	{
1c2555ef	212	zfs_mnt_t zm = { .mnt_osname = NULL, .mnt_data = data };
7fad6290	213	fstrans_cookie_t cookie;
0de19dad	214	int error;
7fad6290 BB	215
7fad6290 BB	216	cookie = spl_fstrans_mark();
1c2555ef	217	error = -zfs_remount(sb, flags, &zm);
7fad6290	218	spl_fstrans_unmark(cookie);
0de19dad BB	219	ASSERT3S(error, <=, 0);
	220
	221	return (error);
	222	}
	223
51f0bbe4	224	static int
0037b49e	225	__zpl_show_options(struct seq_file seq, zfsvfs_t zfsvfs)
51f0bbe4	226	{
0037b49e BB	227	seq_printf(seq, ",%s",
0037b49e BB	228	zfsvfs->z_flags & ZSB_XATTR ? "xattr" : "noxattr");
47621f3d	229
b695c34e	230	#ifdef CONFIG_FS_POSIX_ACL
0037b49e	231	switch (zfsvfs->z_acl_type) {
023699cd MM	232	case ZFS_ACLTYPE_POSIXACL:
	233	seq_puts(seq, ",posixacl");
	234	break;
	235	default:
	236	seq_puts(seq, ",noacl");
	237	break;
	238	}
b695c34e	239	#endif /* CONFIG_FS_POSIX_ACL */
023699cd	240
47621f3d BB	241	return (0);
47621f3d BB	242	}
023699cd MM	243
	244	#ifdef HAVE_SHOW_OPTIONS_WITH_DENTRY
	245	static int
	246	zpl_show_options(struct seq_file seq, struct dentry root)
	247	{
d1d7e268	248	return (__zpl_show_options(seq, root->d_sb->s_fs_info));
023699cd	249	}
47621f3d BB	250	#else
	251	static int
	252	zpl_show_options(struct seq_file seq, struct vfsmount vfsp)
	253	{
d1d7e268	254	return (__zpl_show_options(seq, vfsp->mnt_sb->s_fs_info));
51f0bbe4	255	}
47621f3d	256	#endif /* HAVE_SHOW_OPTIONS_WITH_DENTRY */
51f0bbe4 BB	257
	258	static int
	259	zpl_fill_super(struct super_block sb, void data, int silent)
	260	{
1c2555ef	261	zfs_mnt_t zm = (zfs_mnt_t )data;
7fad6290	262	fstrans_cookie_t cookie;
51f0bbe4 BB	263	int error;
51f0bbe4 BB	264
7fad6290	265	cookie = spl_fstrans_mark();
1c2555ef	266	error = -zfs_domount(sb, zm, silent);
7fad6290	267	spl_fstrans_unmark(cookie);
51f0bbe4 BB	268	ASSERT3S(error, <=, 0);
	269
	270	return (error);
	271	}
	272
93b43af1 SF	273	static int
	274	zpl_test_super(struct super_block s, void data)
	275	{
	276	zfsvfs_t *zfsvfs = s->s_fs_info;
	277	objset_t *os = data;
	278
	279	if (zfsvfs == NULL)
	280	return (0);
	281
	282	return (os == zfsvfs->z_os);
	283	}
	284
	285	static struct super_block *
	286	zpl_mount_impl(struct file_system_type fs_type, int flags, zfs_mnt_t zm)
	287	{
	288	struct super_block *s;
	289	objset_t *os;
	290	int err;
	291
	292	err = dmu_objset_hold(zm->mnt_osname, FTAG, &os);
	293	if (err)
	294	return (ERR_PTR(-err));
	295
ac09630d BB	296	/*
	297	* The dsl pool lock must be released prior to calling sget().
	298	* It is possible sget() may block on the lock in grab_super()
	299	* while deactivate_super() holds that same lock and waits for
e1cfd73f	300	* a txg sync. If the dsl_pool lock is held over sget()
ac09630d BB	301	* this can prevent the pool sync and cause a deadlock.
	302	*/
	303	dsl_pool_rele(dmu_objset_pool(os), FTAG);
93b43af1	304	s = zpl_sget(fs_type, zpl_test_super, set_anon_super, flags, os);
ac09630d BB	305	dsl_dataset_rele(dmu_objset_ds(os), FTAG);
ac09630d BB	306
93b43af1 SF	307	if (IS_ERR(s))
	308	return (ERR_CAST(s));
	309
	310	if (s->s_root == NULL) {
	311	err = zpl_fill_super(s, zm, flags & SB_SILENT ? 1 : 0);
	312	if (err) {
	313	deactivate_locked_super(s);
	314	return (ERR_PTR(err));
	315	}
	316	s->s_flags \|= SB_ACTIVE;
	317	} else if ((flags ^ s->s_flags) & SB_RDONLY) {
	318	deactivate_locked_super(s);
	319	return (ERR_PTR(-EBUSY));
	320	}
	321
	322	return (s);
	323	}
	324
	325	#ifdef HAVE_FST_MOUNT
2cf7f52b BB	326	static struct dentry *
	327	zpl_mount(struct file_system_type *fs_type, int flags,
	328	const char osname, void data)
	329	{
1c2555ef	330	zfs_mnt_t zm = { .mnt_osname = osname, .mnt_data = data };
2cf7f52b	331
93b43af1 SF	332	struct super_block *sb = zpl_mount_impl(fs_type, flags, &zm);
	333	if (IS_ERR(sb))
	334	return (ERR_CAST(sb));
	335
	336	return (dget(sb->s_root));
2cf7f52b BB	337	}
2cf7f52b BB	338	#else
51f0bbe4 BB	339	static int
	340	zpl_get_sb(struct file_system_type *fs_type, int flags,
	341	const char osname, void data, struct vfsmount *mnt)
	342	{
1c2555ef	343	zfs_mnt_t zm = { .mnt_osname = osname, .mnt_data = data };
51f0bbe4	344
93b43af1 SF	345	struct super_block *sb = zpl_mount_impl(fs_type, flags, &zm);
	346	if (IS_ERR(sb))
	347	return (PTR_ERR(sb));
	348
	349	(void) simple_set_mnt(mnt, sb);
	350
	351	return (0);
51f0bbe4	352	}
93b43af1	353	#endif /* HAVE_FST_MOUNT */
51f0bbe4 BB	354
	355	static void
	356	zpl_kill_sb(struct super_block *sb)
	357	{
ebe7e575	358	zfs_preumount(sb);
51f0bbe4	359	kill_anon_super(sb);
dba1d705 BB	360
	361	#ifdef HAVE_S_INSTANCES_LIST_HEAD
	362	sb->s_instances.next = &(zpl_fs_type.fs_supers);
	363	#endif /* HAVE_S_INSTANCES_LIST_HEAD */
51f0bbe4 BB	364	}
51f0bbe4 BB	365
ab26409d	366	void
2cbb06b5	367	zpl_prune_sb(int64_t nr_to_scan, void *arg)
ab26409d	368	{
2cbb06b5 BB	369	struct super_block sb = (struct super_block )arg;
2cbb06b5 BB	370	int objects = 0;
ab26409d	371
f298b24d	372	(void) -zfs_prune(sb, nr_to_scan, &objects);
050d22b0	373	}
ab26409d BB	374
	375	#ifdef HAVE_NR_CACHED_OBJECTS
	376	static int
	377	zpl_nr_cached_objects(struct super_block *sb)
	378	{
04870568	379	return (0);
ab26409d BB	380	}
	381	#endif /* HAVE_NR_CACHED_OBJECTS */
	382
	383	#ifdef HAVE_FREE_CACHED_OBJECTS
ab26409d BB	384	static void
	385	zpl_free_cached_objects(struct super_block *sb, int nr_to_scan)
	386	{
94520ca4	387	/* noop */
ab26409d BB	388	}
	389	#endif /* HAVE_FREE_CACHED_OBJECTS */
	390
51f0bbe4	391	const struct super_operations zpl_super_operations = {
ab26409d BB	392	.alloc_inode = zpl_inode_alloc,
ab26409d BB	393	.destroy_inode = zpl_inode_destroy,
8780c539	394	.dirty_inode = zpl_dirty_inode,
ab26409d	395	.write_inode = NULL,
2c395def	396	#ifdef HAVE_EVICT_INODE
ab26409d	397	.evict_inode = zpl_evict_inode,
2c395def	398	#else
2cbb06b5	399	.drop_inode = zpl_drop_inode,
ab26409d BB	400	.clear_inode = zpl_clear_inode,
ab26409d BB	401	.delete_inode = zpl_inode_delete,
2c395def	402	#endif /* HAVE_EVICT_INODE */
ab26409d	403	.put_super = zpl_put_super,
ab26409d BB	404	.sync_fs = zpl_sync_fs,
	405	.statfs = zpl_statfs,
	406	.remount_fs = zpl_remount_fs,
	407	.show_options = zpl_show_options,
	408	.show_stats = NULL,
	409	#ifdef HAVE_NR_CACHED_OBJECTS
	410	.nr_cached_objects = zpl_nr_cached_objects,
	411	#endif /* HAVE_NR_CACHED_OBJECTS */
	412	#ifdef HAVE_FREE_CACHED_OBJECTS
	413	.free_cached_objects = zpl_free_cached_objects,
	414	#endif /* HAVE_FREE_CACHED_OBJECTS */
51f0bbe4 BB	415	};
51f0bbe4 BB	416
51f0bbe4	417	struct file_system_type zpl_fs_type = {
ab26409d BB	418	.owner = THIS_MODULE,
ab26409d BB	419	.name = ZFS_DRIVER,
93b43af1	420	#ifdef HAVE_FST_MOUNT
ab26409d	421	.mount = zpl_mount,
2cf7f52b	422	#else
ab26409d	423	.get_sb = zpl_get_sb,
93b43af1	424	#endif /* HAVE_FST_MOUNT */
ab26409d	425	.kill_sb = zpl_kill_sb,
51f0bbe4	426	};