[deliverable/linux.git] / fs / xfs / linux-2.6 / 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;

	/* filesystem may contain 64bit inode numbers */
	if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS))
		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)
		return 255;
	*max_len = len;

	switch (fileid_type) {
	case FILEID_INO32_GEN_PARENT:
		spin_lock(&dentry->d_lock);
		fid->i32.parent_ino = 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 = 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 = 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 = 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 = ESTALE;
		return ERR_PTR(-error);
	}

	if (ip->i_d.di_gen != generation) {
		IRELE(ip);
		return ERR_PTR(-ENOENT);
	}

	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;
	int			error = 0;

	xfs_ilock(ip, XFS_ILOCK_SHARED);
	if (xfs_ipincount(ip)) {
		error = _xfs_log_force_lsn(mp, ip->i_itemp->ili_last_lsn,
				XFS_LOG_SYNC, NULL);
	}
	xfs_iunlock(ip, XFS_ILOCK_SHARED);

	return error;
}

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
	73	/* filesystem may contain 64bit inode numbers */
	74	if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS))
	75	fileid_type \|= XFS_FILEID_TYPE_64FLAG;
1da177e4 LT	76
	77	/*
	78	* Only encode if there is enough space given. In practice
	79	* this means we can't export a filesystem with 64bit inodes
	80	* over NFSv2 with the subtree_check export option; the other
	81	* seven combinations work. The real answer is "don't use v2".
	82	*/
c38344fe	83	len = xfs_fileid_length(fileid_type);
1da177e4 LT	84	if (*max_len < len)
	85	return 255;
	86	*max_len = len;
	87
c38344fe CH	88	switch (fileid_type) {
c38344fe CH	89	case FILEID_INO32_GEN_PARENT:
1da177e4	90	spin_lock(&dentry->d_lock);
c38344fe CH	91	fid->i32.parent_ino = dentry->d_parent->d_inode->i_ino;
c38344fe CH	92	fid->i32.parent_gen = dentry->d_parent->d_inode->i_generation;
1da177e4	93	spin_unlock(&dentry->d_lock);
c38344fe CH	94	/FALLTHRU/
	95	case FILEID_INO32_GEN:
	96	fid->i32.ino = inode->i_ino;
	97	fid->i32.gen = inode->i_generation;
	98	break;
	99	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	100	spin_lock(&dentry->d_lock);
	101	fid64->parent_ino = dentry->d_parent->d_inode->i_ino;
	102	fid64->parent_gen = dentry->d_parent->d_inode->i_generation;
	103	spin_unlock(&dentry->d_lock);
	104	/FALLTHRU/
	105	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	106	fid64->ino = inode->i_ino;
	107	fid64->gen = inode->i_generation;
	108	break;
1da177e4	109	}
c38344fe CH	110
c38344fe CH	111	return fileid_type;
1da177e4 LT	112	}
1da177e4 LT	113
c38344fe CH	114	STATIC struct inode *
c38344fe CH	115	xfs_nfs_get_inode(
1da177e4	116	struct super_block *sb,
c38344fe CH	117	u64 ino,
	118	u32 generation)
	119	{
f71354bc CH	120	xfs_mount_t *mp = XFS_M(sb);
f71354bc CH	121	xfs_inode_t *ip;
1da177e4 LT	122	int error;
1da177e4 LT	123
f71354bc CH	124	/*
	125	* NFS can sometimes send requests for ino 0. Fail them gracefully.
	126	*/
	127	if (ino == 0)
	128	return ERR_PTR(-ESTALE);
1da177e4	129
c9a98553	130	/*
1920779e DC	131	* The XFS_IGET_UNTRUSTED means that an invalid inode number is just
	132	* fine and not an indication of a corrupted filesystem as clients can
	133	* send invalid file handles and we have to handle it gracefully..
c9a98553	134	*/
ef35e925	135	error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
c9a98553 CH	136	if (error) {
	137	/*
	138	* EINVAL means the inode cluster doesn't exist anymore.
	139	* This implies the filehandle is stale, so we should
	140	* translate it here.
	141	* We don't use ESTALE directly down the chain to not
	142	* confuse applications using bulkstat that expect EINVAL.
	143	*/
	144	if (error == EINVAL)
	145	error = ESTALE;
c38344fe	146	return ERR_PTR(-error);
c9a98553	147	}
f71354bc	148
6a7f422d	149	if (ip->i_d.di_gen != generation) {
ef35e925	150	IRELE(ip);
f71354bc CH	151	return ERR_PTR(-ENOENT);
f71354bc CH	152	}
c38344fe	153
01651646	154	return VFS_I(ip);
c38344fe CH	155	}
	156
	157	STATIC struct dentry *
	158	xfs_fs_fh_to_dentry(struct super_block sb, struct fid fid,
	159	int fh_len, int fileid_type)
	160	{
	161	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	162	struct inode *inode = NULL;
c38344fe CH	163
	164	if (fh_len < xfs_fileid_length(fileid_type))
	165	return NULL;
	166
	167	switch (fileid_type) {
	168	case FILEID_INO32_GEN_PARENT:
	169	case FILEID_INO32_GEN:
	170	inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
	171	break;
	172	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	173	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	174	inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
	175	break;
	176	}
	177
44003728	178	return d_obtain_alias(inode);
c38344fe CH	179	}
	180
	181	STATIC struct dentry *
	182	xfs_fs_fh_to_parent(struct super_block sb, struct fid fid,
	183	int fh_len, int fileid_type)
	184	{
	185	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	186	struct inode *inode = NULL;
c38344fe CH	187
	188	switch (fileid_type) {
	189	case FILEID_INO32_GEN_PARENT:
	190	inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
	191	fid->i32.parent_gen);
	192	break;
	193	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	194	inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
	195	fid64->parent_gen);
	196	break;
	197	}
	198
44003728	199	return d_obtain_alias(inode);
1da177e4 LT	200	}
	201
	202	STATIC struct dentry *
a50cd269	203	xfs_fs_get_parent(
1da177e4 LT	204	struct dentry *child)
	205	{
	206	int error;
ef1f5e7a	207	struct xfs_inode *cip;
1da177e4	208
384f3ced	209	error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL);
1da177e4 LT	210	if (unlikely(error))
	211	return ERR_PTR(-error);
	212
44003728	213	return d_obtain_alias(VFS_I(cip));
1da177e4 LT	214	}
1da177e4 LT	215
978ebd97 BM	216	STATIC int
	217	xfs_fs_nfs_commit_metadata(
	218	struct inode *inode)
	219	{
	220	struct xfs_inode *ip = XFS_I(inode);
	221	struct xfs_mount *mp = ip->i_mount;
	222	int error = 0;
	223
	224	xfs_ilock(ip, XFS_ILOCK_SHARED);
	225	if (xfs_ipincount(ip)) {
4ea41e2d BF	226	error = _xfs_log_force_lsn(mp, ip->i_itemp->ili_last_lsn,
4ea41e2d BF	227	XFS_LOG_SYNC, NULL);
978ebd97 BM	228	}
	229	xfs_iunlock(ip, XFS_ILOCK_SHARED);
	230
	231	return error;
	232	}
	233
39655164	234	const struct export_operations xfs_export_operations = {
a50cd269	235	.encode_fh = xfs_fs_encode_fh,
c38344fe CH	236	.fh_to_dentry = xfs_fs_fh_to_dentry,
c38344fe CH	237	.fh_to_parent = xfs_fs_fh_to_parent,
a50cd269	238	.get_parent = xfs_fs_get_parent,
978ebd97	239	.commit_metadata = xfs_fs_nfs_commit_metadata,
1da177e4	240	};