Commit f5d92749 authored by Chandan Babu R's avatar Chandan Babu R Committed by Darrick J. Wong
Browse files

xfs: Check for extent overflow when adding dir entries 



Directory entry addition can cause the following,
1. Data block can be added/removed.
   A new extent can cause extent count to increase by 1.
2. Free disk block can be added/removed.
   Same behaviour as described above for Data block.
3. Dabtree blocks.
   XFS_DA_NODE_MAXDEPTH blocks can be added. Each of these
   can be new extents. Hence extent count can increase by
   XFS_DA_NODE_MAXDEPTH.

Signed-off-by: default avatarChandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
parent 85ef08b5

fs/xfs/libxfs/xfs_inode_fork.h

+13 −0
Original line number Diff line number Diff line
@@ -47,6 +47,19 @@ struct xfs_ifork { 
 */

#define XFS_IEXT_PUNCH_HOLE_CNT		(1)



/*

 * Directory entry addition can cause the following,

 * 1. Data block can be added/removed.

 *    A new extent can cause extent count to increase by 1.

 * 2. Free disk block can be added/removed.

 *    Same behaviour as described above for Data block.

 * 3. Dabtree blocks.

 *    XFS_DA_NODE_MAXDEPTH blocks can be added. Each of these can be new

 *    extents. Hence extent count can increase by XFS_DA_NODE_MAXDEPTH.

 */

#define XFS_IEXT_DIR_MANIP_CNT(mp) \

	((XFS_DA_NODE_MAXDEPTH + 1 + 1) * (mp)->m_dir_geo->fsbcount)



/*

 * Fork handling.

 */

fs/xfs/xfs_inode.c

+10 −0
Original line number Diff line number Diff line
@@ -1042,6 +1042,11 @@ xfs_create( 
	if (error)

		goto out_trans_cancel;



	error = xfs_iext_count_may_overflow(dp, XFS_DATA_FORK,

			XFS_IEXT_DIR_MANIP_CNT(mp));

	if (error)

		goto out_trans_cancel;



	/*

	 * A newly created regular or special file just has one directory

	 * entry pointing to them, but a directory also the "." entry
@@ -1258,6 +1263,11 @@ xfs_link( 
	xfs_trans_ijoin(tp, sip, XFS_ILOCK_EXCL);

	xfs_trans_ijoin(tp, tdp, XFS_ILOCK_EXCL);



	error = xfs_iext_count_may_overflow(tdp, XFS_DATA_FORK,

			XFS_IEXT_DIR_MANIP_CNT(mp));

	if (error)

		goto error_return;



	/*

	 * If we are using project inheritance, we only allow hard link

	 * creation in our tree when the project IDs are the same; else

fs/xfs/xfs_symlink.c

+5 −0
Original line number Diff line number Diff line
@@ -220,6 +220,11 @@ xfs_symlink( 
	if (error)

		goto out_trans_cancel;



	error = xfs_iext_count_may_overflow(dp, XFS_DATA_FORK,

			XFS_IEXT_DIR_MANIP_CNT(mp));

	if (error)

		goto out_trans_cancel;



	/*

	 * Allocate an inode for the symlink.

	 */