[GitHub/mt8127/android_kernel_alcatel_ttab.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_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"
#include "xfs_icache.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 (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;

	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(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"
1da177e4 LT	20	#include "xfs_log.h"
	21	#include "xfs_trans.h"
	22	#include "xfs_sb.h"
da353b0d	23	#include "xfs_ag.h"
556b8b16	24	#include "xfs_dir2.h"
1da177e4 LT	25	#include "xfs_mount.h"
1da177e4 LT	26	#include "xfs_export.h"
739bfb2a CH	27	#include "xfs_vnodeops.h"
	28	#include "xfs_bmap_btree.h"
	29	#include "xfs_inode.h"
978ebd97	30	#include "xfs_inode_item.h"
ef35e925	31	#include "xfs_trace.h"
33479e05	32	#include "xfs_icache.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	}
94e07a75	51	return FILEID_INVALID;
1da177e4 LT	52	}
1da177e4 LT	53
1da177e4	54	STATIC int
a50cd269	55	xfs_fs_encode_fh(
b0b0382b AV	56	struct inode *inode,
	57	__u32 *fh,
	58	int *max_len,
	59	struct inode *parent)
1da177e4	60	{
c38344fe CH	61	struct fid fid = (struct fid )fh;
c38344fe CH	62	struct xfs_fid64 fid64 = (struct xfs_fid64 )fh;
c38344fe	63	int fileid_type;
1da177e4	64	int len;
1da177e4 LT	65
1da177e4 LT	66	/* Directories don't need their parent encoded, they have ".." */
b0b0382b	67	if (!parent)
c38344fe CH	68	fileid_type = FILEID_INO32_GEN;
	69	else
	70	fileid_type = FILEID_INO32_GEN_PARENT;
	71
576ecb8e SK	72	/*
	73	* If the the filesystem may contain 64bit inode numbers, we need
	74	* to use larger file handles that can represent them.
	75	*
	76	* While we only allocate inodes that do not fit into 32 bits any
	77	* large enough filesystem may contain them, thus the slightly
	78	* confusing looking conditional below.
	79	*/
	80	if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) \|\|
	81	(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES))
c38344fe	82	fileid_type \|= XFS_FILEID_TYPE_64FLAG;
1da177e4 LT	83
	84	/*
	85	* Only encode if there is enough space given. In practice
	86	* this means we can't export a filesystem with 64bit inodes
	87	* over NFSv2 with the subtree_check export option; the other
	88	* seven combinations work. The real answer is "don't use v2".
	89	*/
c38344fe	90	len = xfs_fileid_length(fileid_type);
5fe0c237 AK	91	if (*max_len < len) {
5fe0c237 AK	92	*max_len = len;
94e07a75	93	return FILEID_INVALID;
5fe0c237	94	}
1da177e4 LT	95	*max_len = len;
1da177e4 LT	96
c38344fe CH	97	switch (fileid_type) {
c38344fe CH	98	case FILEID_INO32_GEN_PARENT:
b0b0382b AV	99	fid->i32.parent_ino = XFS_I(parent)->i_ino;
b0b0382b AV	100	fid->i32.parent_gen = parent->i_generation;
c38344fe CH	101	/FALLTHRU/
c38344fe CH	102	case FILEID_INO32_GEN:
c29f7d45	103	fid->i32.ino = XFS_I(inode)->i_ino;
c38344fe CH	104	fid->i32.gen = inode->i_generation;
	105	break;
	106	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
b0b0382b AV	107	fid64->parent_ino = XFS_I(parent)->i_ino;
b0b0382b AV	108	fid64->parent_gen = parent->i_generation;
c38344fe CH	109	/FALLTHRU/
c38344fe CH	110	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
c29f7d45	111	fid64->ino = XFS_I(inode)->i_ino;
c38344fe CH	112	fid64->gen = inode->i_generation;
c38344fe CH	113	break;
1da177e4	114	}
c38344fe CH	115
c38344fe CH	116	return fileid_type;
1da177e4 LT	117	}
1da177e4 LT	118
c38344fe CH	119	STATIC struct inode *
c38344fe CH	120	xfs_nfs_get_inode(
1da177e4	121	struct super_block *sb,
c38344fe CH	122	u64 ino,
	123	u32 generation)
	124	{
f71354bc CH	125	xfs_mount_t *mp = XFS_M(sb);
f71354bc CH	126	xfs_inode_t *ip;
1da177e4 LT	127	int error;
1da177e4 LT	128
f71354bc CH	129	/*
	130	* NFS can sometimes send requests for ino 0. Fail them gracefully.
	131	*/
	132	if (ino == 0)
	133	return ERR_PTR(-ESTALE);
1da177e4	134
c9a98553	135	/*
1920779e DC	136	* The XFS_IGET_UNTRUSTED means that an invalid inode number is just
	137	* fine and not an indication of a corrupted filesystem as clients can
	138	* send invalid file handles and we have to handle it gracefully..
c9a98553	139	*/
ef35e925	140	error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
c9a98553 CH	141	if (error) {
	142	/*
	143	* EINVAL means the inode cluster doesn't exist anymore.
	144	* This implies the filehandle is stale, so we should
	145	* translate it here.
	146	* We don't use ESTALE directly down the chain to not
	147	* confuse applications using bulkstat that expect EINVAL.
	148	*/
ad1a2c87	149	if (error == EINVAL \|\| error == ENOENT)
c9a98553	150	error = ESTALE;
c38344fe	151	return ERR_PTR(-error);
c9a98553	152	}
f71354bc	153
6a7f422d	154	if (ip->i_d.di_gen != generation) {
ef35e925	155	IRELE(ip);
ad1a2c87	156	return ERR_PTR(-ESTALE);
f71354bc	157	}
c38344fe	158
01651646	159	return VFS_I(ip);
c38344fe CH	160	}
	161
	162	STATIC struct dentry *
	163	xfs_fs_fh_to_dentry(struct super_block sb, struct fid fid,
	164	int fh_len, int fileid_type)
	165	{
	166	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	167	struct inode *inode = NULL;
c38344fe CH	168
	169	if (fh_len < xfs_fileid_length(fileid_type))
	170	return NULL;
	171
	172	switch (fileid_type) {
	173	case FILEID_INO32_GEN_PARENT:
	174	case FILEID_INO32_GEN:
	175	inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
	176	break;
	177	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	178	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	179	inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
	180	break;
	181	}
	182
44003728	183	return d_obtain_alias(inode);
c38344fe CH	184	}
	185
	186	STATIC struct dentry *
	187	xfs_fs_fh_to_parent(struct super_block sb, struct fid fid,
	188	int fh_len, int fileid_type)
	189	{
	190	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	191	struct inode *inode = NULL;
c38344fe	192
35c2a7f4 HD	193	if (fh_len < xfs_fileid_length(fileid_type))
	194	return NULL;
	195
c38344fe CH	196	switch (fileid_type) {
	197	case FILEID_INO32_GEN_PARENT:
	198	inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
	199	fid->i32.parent_gen);
	200	break;
	201	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	202	inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
	203	fid64->parent_gen);
	204	break;
	205	}
	206
44003728	207	return d_obtain_alias(inode);
1da177e4 LT	208	}
	209
	210	STATIC struct dentry *
a50cd269	211	xfs_fs_get_parent(
1da177e4 LT	212	struct dentry *child)
	213	{
	214	int error;
ef1f5e7a	215	struct xfs_inode *cip;
1da177e4	216
384f3ced	217	error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL);
1da177e4 LT	218	if (unlikely(error))
	219	return ERR_PTR(-error);
	220
44003728	221	return d_obtain_alias(VFS_I(cip));
1da177e4 LT	222	}
1da177e4 LT	223
978ebd97 BM	224	STATIC int
	225	xfs_fs_nfs_commit_metadata(
	226	struct inode *inode)
	227	{
	228	struct xfs_inode *ip = XFS_I(inode);
	229	struct xfs_mount *mp = ip->i_mount;
8292d88c	230	xfs_lsn_t lsn = 0;
978ebd97 BM	231
978ebd97 BM	232	xfs_ilock(ip, XFS_ILOCK_SHARED);
8292d88c CH	233	if (xfs_ipincount(ip))
8292d88c CH	234	lsn = ip->i_itemp->ili_last_lsn;
978ebd97 BM	235	xfs_iunlock(ip, XFS_ILOCK_SHARED);
978ebd97 BM	236
8292d88c CH	237	if (!lsn)
	238	return 0;
	239	return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
978ebd97 BM	240	}
978ebd97 BM	241
39655164	242	const struct export_operations xfs_export_operations = {
a50cd269	243	.encode_fh = xfs_fs_encode_fh,
c38344fe CH	244	.fh_to_dentry = xfs_fs_fh_to_dentry,
c38344fe CH	245	.fh_to_parent = xfs_fs_fh_to_parent,
a50cd269	246	.get_parent = xfs_fs_get_parent,
978ebd97	247	.commit_metadata = xfs_fs_nfs_commit_metadata,
1da177e4	248	};