[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_dmapi.h"
#include "xfs_mount.h"
#include "xfs_export.h"
#include "xfs_vnodeops.h"
#include "xfs_bmap_btree.h"
#include "xfs_inode.h"
#include "xfs_vfsops.h"

static struct dentry dotdot = { .d_name.name = "..", .d_name.len = 2, };

/*
 * 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))
		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);

	error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_SHARED, &ip, 0);
	if (error)
		return ERR_PTR(-error);
	if (!ip)
		return ERR_PTR(-EIO);

	if (!ip->i_d.di_mode || ip->i_d.di_gen != generation) {
		xfs_iput_new(ip, XFS_ILOCK_SHARED);
		return ERR_PTR(-ENOENT);
	}

	xfs_iunlock(ip, XFS_ILOCK_SHARED);
	return ip->i_vnode;
}

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;
	struct dentry		*result;

	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;
	}

	if (!inode)
		return NULL;
	if (IS_ERR(inode))
		return ERR_PTR(PTR_ERR(inode));
	result = d_alloc_anon(inode);
	if (!result) {
		iput(inode);
		return ERR_PTR(-ENOMEM);
	}
	return result;
}

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;
	struct dentry		*result;

	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;
	}

	if (!inode)
		return NULL;
	if (IS_ERR(inode))
		return ERR_PTR(PTR_ERR(inode));
	result = d_alloc_anon(inode);
	if (!result) {
		iput(inode);
		return ERR_PTR(-ENOMEM);
	}
	return result;
}

STATIC struct dentry *
xfs_fs_get_parent(
	struct dentry		*child)
{
	int			error;
	bhv_vnode_t		*cvp;
	struct dentry		*parent;

	cvp = NULL;
	error = xfs_lookup(XFS_I(child->d_inode), &dotdot, &cvp);
	if (unlikely(error))
		return ERR_PTR(-error);

	parent = d_alloc_anon(vn_to_inode(cvp));
	if (unlikely(!parent)) {
		VN_RELE(cvp);
		return ERR_PTR(-ENOMEM);
	}
	return parent;
}

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	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 DC	24	#include "xfs_ag.h"
da353b0d DC	25	#include "xfs_dmapi.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"
745f6919	31	#include "xfs_vfsops.h"
1da177e4	32
7989cb8e	33	static struct dentry dotdot = { .d_name.name = "..", .d_name.len = 2, };
9b94c2ed	34
1da177e4	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	}
c38344fe	52	return 255; /* invalid */
1da177e4 LT	53	}
1da177e4 LT	54
1da177e4	55	STATIC int
a50cd269	56	xfs_fs_encode_fh(
1da177e4 LT	57	struct dentry *dentry,
	58	__u32 *fh,
	59	int *max_len,
	60	int connectable)
	61	{
c38344fe CH	62	struct fid fid = (struct fid )fh;
c38344fe CH	63	struct xfs_fid64 fid64 = (struct xfs_fid64 )fh;
1da177e4	64	struct inode *inode = dentry->d_inode;
c38344fe	65	int fileid_type;
1da177e4	66	int len;
1da177e4 LT	67
	68	/* Directories don't need their parent encoded, they have ".." */
	69	if (S_ISDIR(inode->i_mode))
c38344fe CH	70	fileid_type = FILEID_INO32_GEN;
	71	else
	72	fileid_type = FILEID_INO32_GEN_PARENT;
	73
	74	/* filesystem may contain 64bit inode numbers */
	75	if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS))
	76	fileid_type \|= XFS_FILEID_TYPE_64FLAG;
1da177e4 LT	77
	78	/*
	79	* Only encode if there is enough space given. In practice
	80	* this means we can't export a filesystem with 64bit inodes
	81	* over NFSv2 with the subtree_check export option; the other
	82	* seven combinations work. The real answer is "don't use v2".
	83	*/
c38344fe	84	len = xfs_fileid_length(fileid_type);
1da177e4 LT	85	if (*max_len < len)
	86	return 255;
	87	*max_len = len;
	88
c38344fe CH	89	switch (fileid_type) {
c38344fe CH	90	case FILEID_INO32_GEN_PARENT:
1da177e4	91	spin_lock(&dentry->d_lock);
c38344fe CH	92	fid->i32.parent_ino = dentry->d_parent->d_inode->i_ino;
c38344fe CH	93	fid->i32.parent_gen = dentry->d_parent->d_inode->i_generation;
1da177e4	94	spin_unlock(&dentry->d_lock);
c38344fe CH	95	/FALLTHRU/
	96	case FILEID_INO32_GEN:
	97	fid->i32.ino = inode->i_ino;
	98	fid->i32.gen = inode->i_generation;
	99	break;
	100	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	101	spin_lock(&dentry->d_lock);
	102	fid64->parent_ino = dentry->d_parent->d_inode->i_ino;
	103	fid64->parent_gen = dentry->d_parent->d_inode->i_generation;
	104	spin_unlock(&dentry->d_lock);
	105	/FALLTHRU/
	106	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	107	fid64->ino = inode->i_ino;
	108	fid64->gen = inode->i_generation;
	109	break;
1da177e4	110	}
c38344fe CH	111
c38344fe CH	112	return fileid_type;
1da177e4 LT	113	}
1da177e4 LT	114
c38344fe CH	115	STATIC struct inode *
c38344fe CH	116	xfs_nfs_get_inode(
1da177e4	117	struct super_block *sb,
c38344fe CH	118	u64 ino,
	119	u32 generation)
	120	{
f71354bc CH	121	xfs_mount_t *mp = XFS_M(sb);
f71354bc CH	122	xfs_inode_t *ip;
1da177e4 LT	123	int error;
1da177e4 LT	124
f71354bc CH	125	/*
	126	* NFS can sometimes send requests for ino 0. Fail them gracefully.
	127	*/
	128	if (ino == 0)
	129	return ERR_PTR(-ESTALE);
1da177e4	130
f71354bc	131	error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_SHARED, &ip, 0);
c38344fe CH	132	if (error)
c38344fe CH	133	return ERR_PTR(-error);
f71354bc CH	134	if (!ip)
	135	return ERR_PTR(-EIO);
	136
	137	if (!ip->i_d.di_mode \|\| ip->i_d.di_gen != generation) {
	138	xfs_iput_new(ip, XFS_ILOCK_SHARED);
	139	return ERR_PTR(-ENOENT);
	140	}
c38344fe	141
f71354bc CH	142	xfs_iunlock(ip, XFS_ILOCK_SHARED);
f71354bc CH	143	return ip->i_vnode;
c38344fe CH	144	}
	145
	146	STATIC struct dentry *
	147	xfs_fs_fh_to_dentry(struct super_block sb, struct fid fid,
	148	int fh_len, int fileid_type)
	149	{
	150	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	151	struct inode *inode = NULL;
	152	struct dentry *result;
	153
	154	if (fh_len < xfs_fileid_length(fileid_type))
	155	return NULL;
	156
	157	switch (fileid_type) {
	158	case FILEID_INO32_GEN_PARENT:
	159	case FILEID_INO32_GEN:
	160	inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
	161	break;
	162	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	163	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	164	inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
	165	break;
	166	}
	167
	168	if (!inode)
	169	return NULL;
	170	if (IS_ERR(inode))
	171	return ERR_PTR(PTR_ERR(inode));
	172	result = d_alloc_anon(inode);
	173	if (!result) {
	174	iput(inode);
	175	return ERR_PTR(-ENOMEM);
	176	}
	177	return result;
	178	}
	179
	180	STATIC struct dentry *
	181	xfs_fs_fh_to_parent(struct super_block sb, struct fid fid,
	182	int fh_len, int fileid_type)
	183	{
	184	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	185	struct inode *inode = NULL;
	186	struct dentry *result;
	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
	199	if (!inode)
	200	return NULL;
	201	if (IS_ERR(inode))
	202	return ERR_PTR(PTR_ERR(inode));
1da177e4	203	result = d_alloc_anon(inode);
c38344fe	204	if (!result) {
1da177e4 LT	205	iput(inode);
	206	return ERR_PTR(-ENOMEM);
	207	}
	208	return result;
	209	}
	210
	211	STATIC struct dentry *
a50cd269	212	xfs_fs_get_parent(
1da177e4 LT	213	struct dentry *child)
	214	{
	215	int error;
739bfb2a	216	bhv_vnode_t *cvp;
1da177e4	217	struct dentry *parent;
1da177e4 LT	218
1da177e4 LT	219	cvp = NULL;
739bfb2a	220	error = xfs_lookup(XFS_I(child->d_inode), &dotdot, &cvp);
1da177e4 LT	221	if (unlikely(error))
	222	return ERR_PTR(-error);
	223
ec86dc02	224	parent = d_alloc_anon(vn_to_inode(cvp));
1da177e4 LT	225	if (unlikely(!parent)) {
	226	VN_RELE(cvp);
	227	return ERR_PTR(-ENOMEM);
	228	}
	229	return parent;
	230	}
	231
39655164	232	const struct export_operations xfs_export_operations = {
a50cd269	233	.encode_fh = xfs_fs_encode_fh,
c38344fe CH	234	.fh_to_dentry = xfs_fs_fh_to_dentry,
c38344fe CH	235	.fh_to_parent = xfs_fs_fh_to_parent,
a50cd269	236	.get_parent = xfs_fs_get_parent,
1da177e4	237	};