[mirror_ubuntu-jammy-kernel.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_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"

/*
 * 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);

	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_gen != generation) {
		xfs_iput_new(ip, XFS_ILOCK_SHARED);
		return ERR_PTR(-ENOENT);
	}

	xfs_iunlock(ip, XFS_ILOCK_SHARED);
	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;
	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;
	struct xfs_inode	*cip;
	struct dentry		*parent;

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

	parent = d_alloc_anon(VFS_I(cip));
	if (unlikely(!parent)) {
		iput(VFS_I(cip));
		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	24	#include "xfs_ag.h"
556b8b16	25	#include "xfs_dir2.h"
da353b0d	26	#include "xfs_dmapi.h"
1da177e4 LT	27	#include "xfs_mount.h"
1da177e4 LT	28	#include "xfs_export.h"
739bfb2a CH	29	#include "xfs_vnodeops.h"
	30	#include "xfs_bmap_btree.h"
	31	#include "xfs_inode.h"
745f6919	32	#include "xfs_vfsops.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
f71354bc	130	error = xfs_iget(mp, NULL, ino, 0, XFS_ILOCK_SHARED, &ip, 0);
c38344fe CH	131	if (error)
c38344fe CH	132	return ERR_PTR(-error);
f71354bc CH	133	if (!ip)
	134	return ERR_PTR(-EIO);
	135
6a7f422d	136	if (ip->i_d.di_gen != generation) {
f71354bc CH	137	xfs_iput_new(ip, XFS_ILOCK_SHARED);
	138	return ERR_PTR(-ENOENT);
	139	}
c38344fe	140
f71354bc	141	xfs_iunlock(ip, XFS_ILOCK_SHARED);
01651646	142	return VFS_I(ip);
c38344fe CH	143	}
	144
	145	STATIC struct dentry *
	146	xfs_fs_fh_to_dentry(struct super_block sb, struct fid fid,
	147	int fh_len, int fileid_type)
	148	{
	149	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	150	struct inode *inode = NULL;
	151	struct dentry *result;
	152
	153	if (fh_len < xfs_fileid_length(fileid_type))
	154	return NULL;
	155
	156	switch (fileid_type) {
	157	case FILEID_INO32_GEN_PARENT:
	158	case FILEID_INO32_GEN:
	159	inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
	160	break;
	161	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	162	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	163	inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
	164	break;
	165	}
	166
	167	if (!inode)
	168	return NULL;
	169	if (IS_ERR(inode))
	170	return ERR_PTR(PTR_ERR(inode));
	171	result = d_alloc_anon(inode);
	172	if (!result) {
	173	iput(inode);
	174	return ERR_PTR(-ENOMEM);
	175	}
	176	return result;
	177	}
	178
	179	STATIC struct dentry *
	180	xfs_fs_fh_to_parent(struct super_block sb, struct fid fid,
	181	int fh_len, int fileid_type)
	182	{
	183	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	184	struct inode *inode = NULL;
	185	struct dentry *result;
	186
	187	switch (fileid_type) {
	188	case FILEID_INO32_GEN_PARENT:
	189	inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
	190	fid->i32.parent_gen);
	191	break;
	192	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	193	inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
	194	fid64->parent_gen);
	195	break;
	196	}
	197
	198	if (!inode)
	199	return NULL;
	200	if (IS_ERR(inode))
	201	return ERR_PTR(PTR_ERR(inode));
1da177e4	202	result = d_alloc_anon(inode);
c38344fe	203	if (!result) {
1da177e4 LT	204	iput(inode);
	205	return ERR_PTR(-ENOMEM);
	206	}
	207	return result;
	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	struct dentry *parent;
1da177e4	217
384f3ced	218	error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL);
1da177e4 LT	219	if (unlikely(error))
	220	return ERR_PTR(-error);
	221
01651646	222	parent = d_alloc_anon(VFS_I(cip));
1da177e4	223	if (unlikely(!parent)) {
01651646	224	iput(VFS_I(cip));
1da177e4 LT	225	return ERR_PTR(-ENOMEM);
	226	}
	227	return parent;
	228	}
	229
39655164	230	const struct export_operations xfs_export_operations = {
a50cd269	231	.encode_fh = xfs_fs_encode_fh,
c38344fe CH	232	.fh_to_dentry = xfs_fs_fh_to_dentry,
c38344fe CH	233	.fh_to_parent = xfs_fs_fh_to_parent,
a50cd269	234	.get_parent = xfs_fs_get_parent,
1da177e4	235	};