fs/xfs/xfs_export.c - kernel/msm-4.9 - Gitiles

 /*
  * 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_format.h"
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_mount.h"
 #include "xfs_da_format.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"

 /*
  * 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,
 };
	/*
	* 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_format.h"
	#include "xfs_log_format.h"
	#include "xfs_trans_resv.h"
	#include "xfs_mount.h"
	#include "xfs_da_format.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"

	/*
	* 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,
	};