[linux.git] / fs / xfs / xfs_export.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2004-2005 Silicon Graphics, Inc.
 * All Rights Reserved.
 */
#include "xfs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_dir2.h"
#include "xfs_export.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_trace.h"
#include "xfs_icache.h"
#include "xfs_log.h"
#include "xfs_pnfs.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.
		 * EFSCORRUPTED means the metadata pointing to the inode cluster
		 * or the inode cluster itself is corrupt.  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.
		 */
		switch (error) {
		case -EINVAL:
		case -ENOENT:
		case -EFSCORRUPTED:
			error = -ESTALE;
			break;
		default:
			break;
		}
		return ERR_PTR(error);
	}

	if (VFS_I(ip)->i_generation != 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(d_inode(child)), &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,
#ifdef CONFIG_EXPORTFS_BLOCK_OPS
	.get_uuid		= xfs_fs_get_uuid,
	.map_blocks		= xfs_fs_map_blocks,
	.commit_blocks		= xfs_fs_commit_blocks,
#endif
};
Commit	Line	Data
0b61f8a4	1	// SPDX-License-Identifier: GPL-2.0
1da177e4	2	/*
7b718769 NS	3	* Copyright (c) 2004-2005 Silicon Graphics, Inc.
7b718769 NS	4	* All Rights Reserved.
1da177e4	5	*/
1da177e4	6	#include "xfs.h"
a4fbe6ab	7	#include "xfs_format.h"
239880ef DC	8	#include "xfs_log_format.h"
239880ef DC	9	#include "xfs_trans_resv.h"
1da177e4	10	#include "xfs_mount.h"
57062787	11	#include "xfs_da_format.h"
9a2cc41c	12	#include "xfs_da_btree.h"
2b9ab5ab	13	#include "xfs_dir2.h"
1da177e4	14	#include "xfs_export.h"
739bfb2a	15	#include "xfs_inode.h"
239880ef	16	#include "xfs_trans.h"
978ebd97	17	#include "xfs_inode_item.h"
ef35e925	18	#include "xfs_trace.h"
33479e05	19	#include "xfs_icache.h"
239880ef	20	#include "xfs_log.h"
52785112	21	#include "xfs_pnfs.h"
1da177e4 LT	22
1da177e4 LT	23	/*
c38344fe CH	24	* Note that we only accept fileids which are long enough rather than allow
	25	* the parent generation number to default to zero. XFS considers zero a
	26	* valid generation number not an invalid/wildcard value.
1da177e4	27	*/
c38344fe	28	static int xfs_fileid_length(int fileid_type)
1da177e4	29	{
c38344fe CH	30	switch (fileid_type) {
	31	case FILEID_INO32_GEN:
	32	return 2;
	33	case FILEID_INO32_GEN_PARENT:
	34	return 4;
	35	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	36	return 3;
	37	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	38	return 6;
1da177e4	39	}
94e07a75	40	return FILEID_INVALID;
1da177e4 LT	41	}
1da177e4 LT	42
1da177e4	43	STATIC int
a50cd269	44	xfs_fs_encode_fh(
b0b0382b AV	45	struct inode *inode,
	46	__u32 *fh,
	47	int *max_len,
	48	struct inode *parent)
1da177e4	49	{
c38344fe CH	50	struct fid fid = (struct fid )fh;
c38344fe CH	51	struct xfs_fid64 fid64 = (struct xfs_fid64 )fh;
c38344fe	52	int fileid_type;
1da177e4	53	int len;
1da177e4 LT	54
1da177e4 LT	55	/* Directories don't need their parent encoded, they have ".." */
b0b0382b	56	if (!parent)
c38344fe CH	57	fileid_type = FILEID_INO32_GEN;
	58	else
	59	fileid_type = FILEID_INO32_GEN_PARENT;
	60
576ecb8e SK	61	/*
	62	* If the the filesystem may contain 64bit inode numbers, we need
	63	* to use larger file handles that can represent them.
	64	*
	65	* While we only allocate inodes that do not fit into 32 bits any
	66	* large enough filesystem may contain them, thus the slightly
	67	* confusing looking conditional below.
	68	*/
	69	if (!(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_SMALL_INUMS) \|\|
	70	(XFS_M(inode->i_sb)->m_flags & XFS_MOUNT_32BITINODES))
c38344fe	71	fileid_type \|= XFS_FILEID_TYPE_64FLAG;
1da177e4 LT	72
	73	/*
	74	* Only encode if there is enough space given. In practice
	75	* this means we can't export a filesystem with 64bit inodes
	76	* over NFSv2 with the subtree_check export option; the other
	77	* seven combinations work. The real answer is "don't use v2".
	78	*/
c38344fe	79	len = xfs_fileid_length(fileid_type);
5fe0c237 AK	80	if (*max_len < len) {
5fe0c237 AK	81	*max_len = len;
94e07a75	82	return FILEID_INVALID;
5fe0c237	83	}
1da177e4 LT	84	*max_len = len;
1da177e4 LT	85
c38344fe CH	86	switch (fileid_type) {
c38344fe CH	87	case FILEID_INO32_GEN_PARENT:
b0b0382b AV	88	fid->i32.parent_ino = XFS_I(parent)->i_ino;
b0b0382b AV	89	fid->i32.parent_gen = parent->i_generation;
c38344fe CH	90	/FALLTHRU/
c38344fe CH	91	case FILEID_INO32_GEN:
c29f7d45	92	fid->i32.ino = XFS_I(inode)->i_ino;
c38344fe CH	93	fid->i32.gen = inode->i_generation;
	94	break;
	95	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
b0b0382b AV	96	fid64->parent_ino = XFS_I(parent)->i_ino;
b0b0382b AV	97	fid64->parent_gen = parent->i_generation;
c38344fe CH	98	/FALLTHRU/
c38344fe CH	99	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
c29f7d45	100	fid64->ino = XFS_I(inode)->i_ino;
c38344fe CH	101	fid64->gen = inode->i_generation;
c38344fe CH	102	break;
1da177e4	103	}
c38344fe CH	104
c38344fe CH	105	return fileid_type;
1da177e4 LT	106	}
1da177e4 LT	107
c38344fe CH	108	STATIC struct inode *
c38344fe CH	109	xfs_nfs_get_inode(
1da177e4	110	struct super_block *sb,
c38344fe CH	111	u64 ino,
c38344fe CH	112	u32 generation)
447a5647	113	{
f71354bc CH	114	xfs_mount_t *mp = XFS_M(sb);
f71354bc CH	115	xfs_inode_t *ip;
1da177e4 LT	116	int error;
1da177e4 LT	117
f71354bc CH	118	/*
	119	* NFS can sometimes send requests for ino 0. Fail them gracefully.
	120	*/
	121	if (ino == 0)
	122	return ERR_PTR(-ESTALE);
1da177e4	123
c9a98553	124	/*
1920779e DC	125	* The XFS_IGET_UNTRUSTED means that an invalid inode number is just
	126	* fine and not an indication of a corrupted filesystem as clients can
	127	* send invalid file handles and we have to handle it gracefully..
c9a98553	128	*/
ef35e925	129	error = xfs_iget(mp, NULL, ino, XFS_IGET_UNTRUSTED, 0, &ip);
c9a98553	130	if (error) {
29cad0b3	131
c9a98553 CH	132	/*
c9a98553 CH	133	* EINVAL means the inode cluster doesn't exist anymore.
29cad0b3 DC	134	* EFSCORRUPTED means the metadata pointing to the inode cluster
	135	* or the inode cluster itself is corrupt. This implies the
	136	* filehandle is stale, so we should translate it here.
c9a98553 CH	137	* We don't use ESTALE directly down the chain to not
	138	* confuse applications using bulkstat that expect EINVAL.
	139	*/
29cad0b3 DC	140	switch (error) {
	141	case -EINVAL:
	142	case -ENOENT:
	143	case -EFSCORRUPTED:
2451337d	144	error = -ESTALE;
29cad0b3 DC	145	break;
	146	default:
	147	break;
	148	}
2451337d	149	return ERR_PTR(error);
c9a98553	150	}
f71354bc	151
9e9a2674	152	if (VFS_I(ip)->i_generation != generation) {
ef35e925	153	IRELE(ip);
ad1a2c87	154	return ERR_PTR(-ESTALE);
f71354bc	155	}
c38344fe	156
01651646	157	return VFS_I(ip);
c38344fe CH	158	}
	159
	160	STATIC struct dentry *
	161	xfs_fs_fh_to_dentry(struct super_block sb, struct fid fid,
	162	int fh_len, int fileid_type)
	163	{
	164	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	165	struct inode *inode = NULL;
c38344fe CH	166
	167	if (fh_len < xfs_fileid_length(fileid_type))
	168	return NULL;
	169
	170	switch (fileid_type) {
	171	case FILEID_INO32_GEN_PARENT:
	172	case FILEID_INO32_GEN:
	173	inode = xfs_nfs_get_inode(sb, fid->i32.ino, fid->i32.gen);
	174	break;
	175	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	176	case FILEID_INO32_GEN \| XFS_FILEID_TYPE_64FLAG:
	177	inode = xfs_nfs_get_inode(sb, fid64->ino, fid64->gen);
	178	break;
	179	}
	180
44003728	181	return d_obtain_alias(inode);
c38344fe CH	182	}
	183
	184	STATIC struct dentry *
	185	xfs_fs_fh_to_parent(struct super_block sb, struct fid fid,
	186	int fh_len, int fileid_type)
	187	{
	188	struct xfs_fid64 fid64 = (struct xfs_fid64 )fid;
	189	struct inode *inode = NULL;
c38344fe	190
35c2a7f4 HD	191	if (fh_len < xfs_fileid_length(fileid_type))
	192	return NULL;
	193
c38344fe CH	194	switch (fileid_type) {
	195	case FILEID_INO32_GEN_PARENT:
	196	inode = xfs_nfs_get_inode(sb, fid->i32.parent_ino,
	197	fid->i32.parent_gen);
	198	break;
	199	case FILEID_INO32_GEN_PARENT \| XFS_FILEID_TYPE_64FLAG:
	200	inode = xfs_nfs_get_inode(sb, fid64->parent_ino,
	201	fid64->parent_gen);
	202	break;
	203	}
	204
44003728	205	return d_obtain_alias(inode);
1da177e4 LT	206	}
	207
	208	STATIC struct dentry *
a50cd269	209	xfs_fs_get_parent(
1da177e4 LT	210	struct dentry *child)
	211	{
	212	int error;
ef1f5e7a	213	struct xfs_inode *cip;
1da177e4	214
2b0143b5	215	error = xfs_lookup(XFS_I(d_inode(child)), &xfs_name_dotdot, &cip, NULL);
1da177e4	216	if (unlikely(error))
2451337d	217	return ERR_PTR(error);
1da177e4	218
44003728	219	return d_obtain_alias(VFS_I(cip));
1da177e4 LT	220	}
1da177e4 LT	221
978ebd97 BM	222	STATIC int
	223	xfs_fs_nfs_commit_metadata(
	224	struct inode *inode)
	225	{
	226	struct xfs_inode *ip = XFS_I(inode);
	227	struct xfs_mount *mp = ip->i_mount;
8292d88c	228	xfs_lsn_t lsn = 0;
978ebd97 BM	229
978ebd97 BM	230	xfs_ilock(ip, XFS_ILOCK_SHARED);
8292d88c CH	231	if (xfs_ipincount(ip))
8292d88c CH	232	lsn = ip->i_itemp->ili_last_lsn;
978ebd97 BM	233	xfs_iunlock(ip, XFS_ILOCK_SHARED);
978ebd97 BM	234
8292d88c CH	235	if (!lsn)
8292d88c CH	236	return 0;
656de4ff	237	return xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
978ebd97 BM	238	}
978ebd97 BM	239
39655164	240	const struct export_operations xfs_export_operations = {
a50cd269	241	.encode_fh = xfs_fs_encode_fh,
c38344fe CH	242	.fh_to_dentry = xfs_fs_fh_to_dentry,
c38344fe CH	243	.fh_to_parent = xfs_fs_fh_to_parent,
a50cd269	244	.get_parent = xfs_fs_get_parent,
978ebd97	245	.commit_metadata = xfs_fs_nfs_commit_metadata,
15d66ac2	246	#ifdef CONFIG_EXPORTFS_BLOCK_OPS
52785112 CH	247	.get_uuid = xfs_fs_get_uuid,
	248	.map_blocks = xfs_fs_map_blocks,
	249	.commit_blocks = xfs_fs_commit_blocks,
	250	#endif
1da177e4	251	};