[deliverable/linux.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_types.h"
#include "xfs_inum.h"
#include "xfs_log.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_mount.h"
#include "xfs_export.h"
#include "xfs_vnodeops.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_inode_item.h"
#include "xfs_trace.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 255; /* invalid */
}

STATIC int
xfs_fs_encode_fh(
	struct dentry		*dentry,
	__u32			*fh,
	int			*max_len,
	int			connectable)
{
	struct fid		*fid = (struct fid *)fh;
	struct xfs_fid64	*fid64 = (struct xfs_fid64 *)fh;
	struct inode		*inode = dentry->d_inode;
	int			fileid_type;
	int			len;

	/* Directories don't need their parent encoded, they have ".." */
	if (S_ISDIR(inode->i_mode) || !connectable)
		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 255;
	}
	*max_len = len;

	switch (fileid_type) {
	case FILEID_INO32_GEN_PARENT:
		spin_lock(&dentry->d_lock);
		fid->i32.parent_ino = XFS_I(dentry->d_parent->d_inode)->i_ino;
		fid->i32.parent_gen = dentry->d_parent->d_inode->i_generation;
		spin_unlock(&dentry->d_lock);
		/*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:
		spin_lock(&dentry->d_lock);
		fid64->parent_ino = XFS_I(dentry->d_parent->d_inode)->i_ino;
		fid64->parent_gen = dentry->d_parent->d_inode->i_generation;
		spin_unlock(&dentry->d_lock);
		/*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 (ip->i_d.di_gen != 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;

	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(child->d_inode), &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,
};
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 LT	18	#include "xfs.h"
1da177e4 LT	19	#include "xfs_types.h"
da353b0d	20	#include "xfs_inum.h"
1da177e4 LT	21	#include "xfs_log.h"
	22	#include "xfs_trans.h"
	23	#include "xfs_sb.h"
da353b0d	24	#include "xfs_ag.h"
556b8b16	25	#include "xfs_dir2.h"
1da177e4 LT	26	#include "xfs_mount.h"
1da177e4 LT	27	#include "xfs_export.h"
739bfb2a CH	28	#include "xfs_vnodeops.h"
	29	#include "xfs_bmap_btree.h"
	30	#include "xfs_inode.h"
978ebd97	31	#include "xfs_inode_item.h"
ef35e925	32	#include "xfs_trace.h"
1da177e4 LT	33
1da177e4 LT	34	/*
c38344fe CH	35	* Note that we only accept fileids which are long enough rather than allow
	36	* the parent generation number to default to zero. XFS considers zero a
	37	* valid generation number not an invalid/wildcard value.
1da177e4	38	*/
c38344fe	39	static int xfs_fileid_length(int fileid_type)
1da177e4	40	{
c38344fe CH	41	switch (fileid_type) {
	42	case FILEID_INO32_GEN:
	43	return 2;
	44	case FILEID_INO32_GEN_PARENT:
	45	return 4;
	46	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	47	return 3;
	48	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	49	return 6;
1da177e4	50	}
c38344fe	51	return 255; /* invalid */
1da177e4 LT	52	}
1da177e4 LT	53
1da177e4	54	STATIC int
a50cd269	55	xfs_fs_encode_fh(
1da177e4 LT	56	struct dentry *dentry,
	57	__u32 *fh,
	58	int *max_len,
	59	int connectable)
	60	{
c38344fe CH	61	struct fid fid = (struct fid )fh;
c38344fe CH	62	struct xfs_fid64 fid64 = (struct xfs_fid64 )fh;
1da177e4	63	struct inode *inode = dentry->d_inode;
c38344fe	64	int fileid_type;
1da177e4	65	int len;
1da177e4 LT	66
1da177e4 LT	67	/* Directories don't need their parent encoded, they have ".." */
24bd861d	68	if (S_ISDIR(inode->i_mode) \|\| !connectable)
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;
1da177e4	94	return 255;
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:
1da177e4	100	spin_lock(&dentry->d_lock);
c29f7d45	101	fid->i32.parent_ino = XFS_I(dentry->d_parent->d_inode)->i_ino;
c38344fe	102	fid->i32.parent_gen = dentry->d_parent->d_inode->i_generation;
1da177e4	103	spin_unlock(&dentry->d_lock);
c38344fe CH	104	/FALLTHRU/
c38344fe CH	105	case FILEID_INO32_GEN:
c29f7d45	106	fid->i32.ino = XFS_I(inode)->i_ino;
c38344fe CH	107	fid->i32.gen = inode->i_generation;
	108	break;
	109	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	110	spin_lock(&dentry->d_lock);
c29f7d45	111	fid64->parent_ino = XFS_I(dentry->d_parent->d_inode)->i_ino;
c38344fe CH	112	fid64->parent_gen = dentry->d_parent->d_inode->i_generation;
	113	spin_unlock(&dentry->d_lock);
	114	/FALLTHRU/
	115	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
c29f7d45	116	fid64->ino = XFS_I(inode)->i_ino;
c38344fe CH	117	fid64->gen = inode->i_generation;
c38344fe CH	118	break;
1da177e4	119	}
c38344fe CH	120
c38344fe CH	121	return fileid_type;
1da177e4 LT	122	}
1da177e4 LT	123
c38344fe CH	124	STATIC struct inode *
c38344fe CH	125	xfs_nfs_get_inode(
1da177e4	126	struct super_block *sb,
c38344fe CH	127	u64 ino,
	128	u32 generation)
	129	{
f71354bc CH	130	xfs_mount_t *mp = XFS_M(sb);
f71354bc CH	131	xfs_inode_t *ip;
1da177e4 LT	132	int error;
1da177e4 LT	133
f71354bc CH	134	/*
	135	* NFS can sometimes send requests for ino 0. Fail them gracefully.
	136	*/
	137	if (ino == 0)
	138	return ERR_PTR(-ESTALE);
1da177e4	139
c9a98553	140	/*
1920779e DC	141	* The XFS_IGET_UNTRUSTED means that an invalid inode number is just
	142	* fine and not an indication of a corrupted filesystem as clients can
	143	* send invalid file handles and we have to handle it gracefully..
c9a98553	144	*/
ef35e925	145	error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
c9a98553 CH	146	if (error) {
	147	/*
	148	* EINVAL means the inode cluster doesn't exist anymore.
	149	* This implies the filehandle is stale, so we should
	150	* translate it here.
	151	* We don't use ESTALE directly down the chain to not
	152	* confuse applications using bulkstat that expect EINVAL.
	153	*/
ad1a2c87	154	if (error == EINVAL \|\| error == ENOENT)
c9a98553	155	error = ESTALE;
c38344fe	156	return ERR_PTR(-error);
c9a98553	157	}
f71354bc	158
6a7f422d	159	if (ip->i_d.di_gen != generation) {
ef35e925	160	IRELE(ip);
ad1a2c87	161	return ERR_PTR(-ESTALE);
f71354bc	162	}
c38344fe	163
01651646	164	return VFS_I(ip);
c38344fe CH	165	}
	166
	167	STATIC struct dentry *
	168	xfs_fs_fh_to_dentry(struct super_block sb, struct fid fid,
	169	int fh_len, int fileid_type)
	170	{
	171	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	172	struct inode *inode = NULL;
c38344fe CH	173
	174	if (fh_len < xfs_fileid_length(fileid_type))
	175	return NULL;
	176
	177	switch (fileid_type) {
	178	case FILEID_INO32_GEN_PARENT:
	179	case FILEID_INO32_GEN:
	180	inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
	181	break;
	182	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	183	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	184	inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
	185	break;
	186	}
	187
44003728	188	return d_obtain_alias(inode);
c38344fe CH	189	}
	190
	191	STATIC struct dentry *
	192	xfs_fs_fh_to_parent(struct super_block sb, struct fid fid,
	193	int fh_len, int fileid_type)
	194	{
	195	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	196	struct inode *inode = NULL;
c38344fe CH	197
	198	switch (fileid_type) {
	199	case FILEID_INO32_GEN_PARENT:
	200	inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
	201	fid->i32.parent_gen);
	202	break;
	203	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	204	inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
	205	fid64->parent_gen);
	206	break;
	207	}
	208
44003728	209	return d_obtain_alias(inode);
1da177e4 LT	210	}
	211
	212	STATIC struct dentry *
a50cd269	213	xfs_fs_get_parent(
1da177e4 LT	214	struct dentry *child)
	215	{
	216	int error;
ef1f5e7a	217	struct xfs_inode *cip;
1da177e4	218
384f3ced	219	error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL);
1da177e4 LT	220	if (unlikely(error))
	221	return ERR_PTR(-error);
	222
44003728	223	return d_obtain_alias(VFS_I(cip));
1da177e4 LT	224	}
1da177e4 LT	225
978ebd97 BM	226	STATIC int
	227	xfs_fs_nfs_commit_metadata(
	228	struct inode *inode)
	229	{
	230	struct xfs_inode *ip = XFS_I(inode);
	231	struct xfs_mount *mp = ip->i_mount;
8292d88c	232	xfs_lsn_t lsn = 0;
978ebd97 BM	233
978ebd97 BM	234	xfs_ilock(ip, XFS_ILOCK_SHARED);
8292d88c CH	235	if (xfs_ipincount(ip))
8292d88c CH	236	lsn = ip->i_itemp->ili_last_lsn;
978ebd97 BM	237	xfs_iunlock(ip, XFS_ILOCK_SHARED);
978ebd97 BM	238
8292d88c CH	239	if (!lsn)
	240	return 0;
	241	return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
978ebd97 BM	242	}
978ebd97 BM	243
39655164	244	const struct export_operations xfs_export_operations = {
a50cd269	245	.encode_fh = xfs_fs_encode_fh,
c38344fe CH	246	.fh_to_dentry = xfs_fs_fh_to_dentry,
c38344fe CH	247	.fh_to_parent = xfs_fs_fh_to_parent,
a50cd269	248	.get_parent = xfs_fs_get_parent,
978ebd97	249	.commit_metadata = xfs_fs_nfs_commit_metadata,
1da177e4	250	};