[mirror_ubuntu-artful-kernel.git] / fs / xfs / xfs_export.c

/*
 * Copyright (c) 2004-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include "xfs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_dir2.h"
#include "xfs_export.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_trace.h"
#include "xfs_icache.h"
#include "xfs_log.h"
#include "xfs_pnfs.h"

/*
 * Note that we only accept fileids which are long enough rather than allow
 * the parent generation number to default to zero.  XFS considers zero a
 * valid generation number not an invalid/wildcard value.
 */
static int xfs_fileid_length(int fileid_type)
{
	switch (fileid_type) {
	case FILEID_INO32_GEN:
		return 2;
	case FILEID_INO32_GEN_PARENT:
		return 4;
	case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
		return 3;
	case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
		return 6;
	}
	return FILEID_INVALID;
}

STATIC int
xfs_fs_encode_fh(
	struct inode	*inode,
	__u32		*fh,
	int		*max_len,
	struct inode	*parent)
{
	struct fid		*fid = (struct fid *)fh;
	struct xfs_fid64	*fid64 = (struct xfs_fid64 *)fh;
	int			fileid_type;
	int			len;

	/* Directories don't need their parent encoded, they have ".." */
	if (!parent)
		fileid_type = FILEID_INO32_GEN;
	else
		fileid_type = FILEID_INO32_GEN_PARENT;

	/*
	 * If the the filesystem may contain 64bit inode numbers, we need
	 * to use larger file handles that can represent them.
	 *
	 * While we only allocate inodes that do not fit into 32 bits any
	 * large enough filesystem may contain them, thus the slightly
	 * confusing looking conditional below.
	 */
	if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) ||
	    (XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES))
		fileid_type |= XFS_FILEID_TYPE_64FLAG;

	/*
	 * Only encode if there is enough space given.  In practice
	 * this means we can't export a filesystem with 64bit inodes
	 * over NFSv2 with the subtree_check export option; the other
	 * seven combinations work.  The real answer is "don't use v2".
	 */
	len = xfs_fileid_length(fileid_type);
	if (*max_len < len) {
		*max_len = len;
		return FILEID_INVALID;
	}
	*max_len = len;

	switch (fileid_type) {
	case FILEID_INO32_GEN_PARENT:
		fid->i32.parent_ino = XFS_I(parent)->i_ino;
		fid->i32.parent_gen = parent->i_generation;
		/*FALLTHRU*/
	case FILEID_INO32_GEN:
		fid->i32.ino = XFS_I(inode)->i_ino;
		fid->i32.gen = inode->i_generation;
		break;
	case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
		fid64->parent_ino = XFS_I(parent)->i_ino;
		fid64->parent_gen = parent->i_generation;
		/*FALLTHRU*/
	case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
		fid64->ino = XFS_I(inode)->i_ino;
		fid64->gen = inode->i_generation;
		break;
	}

	return fileid_type;
}

STATIC struct inode *
xfs_nfs_get_inode(
	struct super_block	*sb,
	u64			ino,
	u32			generation)
 {
 	xfs_mount_t		*mp = XFS_M(sb);
	xfs_inode_t		*ip;
	int			error;

	/*
	 * NFS can sometimes send requests for ino 0.  Fail them gracefully.
	 */
	if (ino == 0)
		return ERR_PTR(-ESTALE);

	/*
	 * The XFS_IGET_UNTRUSTED means that an invalid inode number is just
	 * fine and not an indication of a corrupted filesystem as clients can
	 * send invalid file handles and we have to handle it gracefully..
	 */
	error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
	if (error) {
		/*
		 * EINVAL means the inode cluster doesn't exist anymore.
		 * This implies the filehandle is stale, so we should
		 * translate it here.
		 * We don't use ESTALE directly down the chain to not
		 * confuse applications using bulkstat that expect EINVAL.
		 */
		if (error == -EINVAL || error == -ENOENT)
			error = -ESTALE;
		return ERR_PTR(error);
	}

	if (VFS_I(ip)->i_generation != generation) {
		IRELE(ip);
		return ERR_PTR(-ESTALE);
	}

	return VFS_I(ip);
}

STATIC struct dentry *
xfs_fs_fh_to_dentry(struct super_block *sb, struct fid *fid,
		 int fh_len, int fileid_type)
{
	struct xfs_fid64	*fid64 = (struct xfs_fid64 *)fid;
	struct inode		*inode = NULL;

	if (fh_len < xfs_fileid_length(fileid_type))
		return NULL;

	switch (fileid_type) {
	case FILEID_INO32_GEN_PARENT:
	case FILEID_INO32_GEN:
		inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
		break;
	case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
	case FILEID_INO32_GEN | XFS_FILEID_TYPE_64FLAG:
		inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
		break;
	}

	return d_obtain_alias(inode);
}

STATIC struct dentry *
xfs_fs_fh_to_parent(struct super_block *sb, struct fid *fid,
		 int fh_len, int fileid_type)
{
	struct xfs_fid64	*fid64 = (struct xfs_fid64 *)fid;
	struct inode		*inode = NULL;

	if (fh_len < xfs_fileid_length(fileid_type))
		return NULL;

	switch (fileid_type) {
	case FILEID_INO32_GEN_PARENT:
		inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
					      fid->i32.parent_gen);
		break;
	case FILEID_INO32_GEN_PARENT | XFS_FILEID_TYPE_64FLAG:
		inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
					      fid64->parent_gen);
		break;
	}

	return d_obtain_alias(inode);
}

STATIC struct dentry *
xfs_fs_get_parent(
	struct dentry		*child)
{
	int			error;
	struct xfs_inode	*cip;

	error = xfs_lookup(XFS_I(d_inode(child)), &xfs_name_dotdot, &cip, NULL);
	if (unlikely(error))
		return ERR_PTR(error);

	return d_obtain_alias(VFS_I(cip));
}

STATIC int
xfs_fs_nfs_commit_metadata(
	struct inode		*inode)
{
	struct xfs_inode	*ip = XFS_I(inode);
	struct xfs_mount	*mp = ip->i_mount;
	xfs_lsn_t		lsn = 0;

	xfs_ilock(ip, XFS_ILOCK_SHARED);
	if (xfs_ipincount(ip))
		lsn = ip->i_itemp->ili_last_lsn;
	xfs_iunlock(ip, XFS_ILOCK_SHARED);

	if (!lsn)
		return 0;
	return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
}

const struct export_operations xfs_export_operations = {
	.encode_fh		= xfs_fs_encode_fh,
	.fh_to_dentry		= xfs_fs_fh_to_dentry,
	.fh_to_parent		= xfs_fs_fh_to_parent,
	.get_parent		= xfs_fs_get_parent,
	.commit_metadata	= xfs_fs_nfs_commit_metadata,
#ifdef CONFIG_EXPORTFS_BLOCK_OPS
	.get_uuid		= xfs_fs_get_uuid,
	.map_blocks		= xfs_fs_map_blocks,
	.commit_blocks		= xfs_fs_commit_blocks,
#endif
};
Commit	Line	Data
1da177e4	1	/*
7b718769 NS	2	* Copyright (c) 2004-2005 Silicon Graphics, Inc.
7b718769 NS	3	* All Rights Reserved.
1da177e4	4	*
7b718769 NS	5	* This program is free software; you can redistribute it and/or
7b718769 NS	6	* modify it under the terms of the GNU General Public License as
1da177e4 LT	7	* published by the Free Software Foundation.
1da177e4 LT	8	*
7b718769 NS	9	* This program is distributed in the hope that it would be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
1da177e4	13	*
7b718769 NS	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write the Free Software Foundation,
	16	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
1da177e4	17	*/
1da177e4	18	#include "xfs.h"
a4fbe6ab	19	#include "xfs_format.h"
239880ef DC	20	#include "xfs_log_format.h"
239880ef DC	21	#include "xfs_trans_resv.h"
1da177e4	22	#include "xfs_mount.h"
57062787	23	#include "xfs_da_format.h"
9a2cc41c	24	#include "xfs_da_btree.h"
2b9ab5ab	25	#include "xfs_dir2.h"
1da177e4	26	#include "xfs_export.h"
739bfb2a	27	#include "xfs_inode.h"
239880ef	28	#include "xfs_trans.h"
978ebd97	29	#include "xfs_inode_item.h"
ef35e925	30	#include "xfs_trace.h"
33479e05	31	#include "xfs_icache.h"
239880ef	32	#include "xfs_log.h"
52785112	33	#include "xfs_pnfs.h"
1da177e4 LT	34
1da177e4 LT	35	/*
c38344fe CH	36	* Note that we only accept fileids which are long enough rather than allow
	37	* the parent generation number to default to zero. XFS considers zero a
	38	* valid generation number not an invalid/wildcard value.
1da177e4	39	*/
c38344fe	40	static int xfs_fileid_length(int fileid_type)
1da177e4	41	{
c38344fe CH	42	switch (fileid_type) {
	43	case FILEID_INO32_GEN:
	44	return 2;
	45	case FILEID_INO32_GEN_PARENT:
	46	return 4;
	47	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	48	return 3;
	49	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	50	return 6;
1da177e4	51	}
94e07a75	52	return FILEID_INVALID;
1da177e4 LT	53	}
1da177e4 LT	54
1da177e4	55	STATIC int
a50cd269	56	xfs_fs_encode_fh(
b0b0382b AV	57	struct inode *inode,
	58	__u32 *fh,
	59	int *max_len,
	60	struct inode *parent)
1da177e4	61	{
c38344fe CH	62	struct fid fid = (struct fid )fh;
c38344fe CH	63	struct xfs_fid64 fid64 = (struct xfs_fid64 )fh;
c38344fe	64	int fileid_type;
1da177e4	65	int len;
1da177e4 LT	66
1da177e4 LT	67	/* Directories don't need their parent encoded, they have ".." */
b0b0382b	68	if (!parent)
c38344fe CH	69	fileid_type = FILEID_INO32_GEN;
	70	else
	71	fileid_type = FILEID_INO32_GEN_PARENT;
	72
576ecb8e SK	73	/*
	74	* If the the filesystem may contain 64bit inode numbers, we need
	75	* to use larger file handles that can represent them.
	76	*
	77	* While we only allocate inodes that do not fit into 32 bits any
	78	* large enough filesystem may contain them, thus the slightly
	79	* confusing looking conditional below.
	80	*/
	81	if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) \|\|
	82	(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES))
c38344fe	83	fileid_type \|= XFS_FILEID_TYPE_64FLAG;
1da177e4 LT	84
	85	/*
	86	* Only encode if there is enough space given. In practice
	87	* this means we can't export a filesystem with 64bit inodes
	88	* over NFSv2 with the subtree_check export option; the other
	89	* seven combinations work. The real answer is "don't use v2".
	90	*/
c38344fe	91	len = xfs_fileid_length(fileid_type);
5fe0c237 AK	92	if (*max_len < len) {
5fe0c237 AK	93	*max_len = len;
94e07a75	94	return FILEID_INVALID;
5fe0c237	95	}
1da177e4 LT	96	*max_len = len;
1da177e4 LT	97
c38344fe CH	98	switch (fileid_type) {
c38344fe CH	99	case FILEID_INO32_GEN_PARENT:
b0b0382b AV	100	fid->i32.parent_ino = XFS_I(parent)->i_ino;
b0b0382b AV	101	fid->i32.parent_gen = parent->i_generation;
c38344fe CH	102	/FALLTHRU/
c38344fe CH	103	case FILEID_INO32_GEN:
c29f7d45	104	fid->i32.ino = XFS_I(inode)->i_ino;
c38344fe CH	105	fid->i32.gen = inode->i_generation;
	106	break;
	107	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
b0b0382b AV	108	fid64->parent_ino = XFS_I(parent)->i_ino;
b0b0382b AV	109	fid64->parent_gen = parent->i_generation;
c38344fe CH	110	/FALLTHRU/
c38344fe CH	111	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
c29f7d45	112	fid64->ino = XFS_I(inode)->i_ino;
c38344fe CH	113	fid64->gen = inode->i_generation;
c38344fe CH	114	break;
1da177e4	115	}
c38344fe CH	116
c38344fe CH	117	return fileid_type;
1da177e4 LT	118	}
1da177e4 LT	119
c38344fe CH	120	STATIC struct inode *
c38344fe CH	121	xfs_nfs_get_inode(
1da177e4	122	struct super_block *sb,
c38344fe CH	123	u64 ino,
	124	u32 generation)
	125	{
f71354bc CH	126	xfs_mount_t *mp = XFS_M(sb);
f71354bc CH	127	xfs_inode_t *ip;
1da177e4 LT	128	int error;
1da177e4 LT	129
f71354bc CH	130	/*
	131	* NFS can sometimes send requests for ino 0. Fail them gracefully.
	132	*/
	133	if (ino == 0)
	134	return ERR_PTR(-ESTALE);
1da177e4	135
c9a98553	136	/*
1920779e DC	137	* The XFS_IGET_UNTRUSTED means that an invalid inode number is just
	138	* fine and not an indication of a corrupted filesystem as clients can
	139	* send invalid file handles and we have to handle it gracefully..
c9a98553	140	*/
ef35e925	141	error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
c9a98553 CH	142	if (error) {
	143	/*
	144	* EINVAL means the inode cluster doesn't exist anymore.
	145	* This implies the filehandle is stale, so we should
	146	* translate it here.
	147	* We don't use ESTALE directly down the chain to not
	148	* confuse applications using bulkstat that expect EINVAL.
	149	*/
2451337d DC	150	if (error == -EINVAL \|\| error == -ENOENT)
	151	error = -ESTALE;
	152	return ERR_PTR(error);
c9a98553	153	}
f71354bc	154
9e9a2674	155	if (VFS_I(ip)->i_generation != generation) {
ef35e925	156	IRELE(ip);
ad1a2c87	157	return ERR_PTR(-ESTALE);
f71354bc	158	}
c38344fe	159
01651646	160	return VFS_I(ip);
c38344fe CH	161	}
	162
	163	STATIC struct dentry *
	164	xfs_fs_fh_to_dentry(struct super_block sb, struct fid fid,
	165	int fh_len, int fileid_type)
	166	{
	167	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	168	struct inode *inode = NULL;
c38344fe CH	169
	170	if (fh_len < xfs_fileid_length(fileid_type))
	171	return NULL;
	172
	173	switch (fileid_type) {
	174	case FILEID_INO32_GEN_PARENT:
	175	case FILEID_INO32_GEN:
	176	inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
	177	break;
	178	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	179	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	180	inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
	181	break;
	182	}
	183
44003728	184	return d_obtain_alias(inode);
c38344fe CH	185	}
	186
	187	STATIC struct dentry *
	188	xfs_fs_fh_to_parent(struct super_block sb, struct fid fid,
	189	int fh_len, int fileid_type)
	190	{
	191	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	192	struct inode *inode = NULL;
c38344fe	193
35c2a7f4 HD	194	if (fh_len < xfs_fileid_length(fileid_type))
	195	return NULL;
	196
c38344fe CH	197	switch (fileid_type) {
	198	case FILEID_INO32_GEN_PARENT:
	199	inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
	200	fid->i32.parent_gen);
	201	break;
	202	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	203	inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
	204	fid64->parent_gen);
	205	break;
	206	}
	207
44003728	208	return d_obtain_alias(inode);
1da177e4 LT	209	}
	210
	211	STATIC struct dentry *
a50cd269	212	xfs_fs_get_parent(
1da177e4 LT	213	struct dentry *child)
	214	{
	215	int error;
ef1f5e7a	216	struct xfs_inode *cip;
1da177e4	217
2b0143b5	218	error = xfs_lookup(XFS_I(d_inode(child)), &xfs_name_dotdot, &cip, NULL);
1da177e4	219	if (unlikely(error))
2451337d	220	return ERR_PTR(error);
1da177e4	221
44003728	222	return d_obtain_alias(VFS_I(cip));
1da177e4 LT	223	}
1da177e4 LT	224
978ebd97 BM	225	STATIC int
	226	xfs_fs_nfs_commit_metadata(
	227	struct inode *inode)
	228	{
	229	struct xfs_inode *ip = XFS_I(inode);
	230	struct xfs_mount *mp = ip->i_mount;
8292d88c	231	xfs_lsn_t lsn = 0;
978ebd97 BM	232
978ebd97 BM	233	xfs_ilock(ip, XFS_ILOCK_SHARED);
8292d88c CH	234	if (xfs_ipincount(ip))
8292d88c CH	235	lsn = ip->i_itemp->ili_last_lsn;
978ebd97 BM	236	xfs_iunlock(ip, XFS_ILOCK_SHARED);
978ebd97 BM	237
8292d88c CH	238	if (!lsn)
8292d88c CH	239	return 0;
2451337d	240	return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
978ebd97 BM	241	}
978ebd97 BM	242
39655164	243	const struct export_operations xfs_export_operations = {
a50cd269	244	.encode_fh = xfs_fs_encode_fh,
c38344fe CH	245	.fh_to_dentry = xfs_fs_fh_to_dentry,
c38344fe CH	246	.fh_to_parent = xfs_fs_fh_to_parent,
a50cd269	247	.get_parent = xfs_fs_get_parent,
978ebd97	248	.commit_metadata = xfs_fs_nfs_commit_metadata,
15d66ac2	249	#ifdef CONFIG_EXPORTFS_BLOCK_OPS
52785112 CH	250	.get_uuid = xfs_fs_get_uuid,
	251	.map_blocks = xfs_fs_map_blocks,
	252	.commit_blocks = xfs_fs_commit_blocks,
	253	#endif
1da177e4	254	};