Commit 3a19bb14 authored by Chandan Babu R's avatar Chandan Babu R Committed by Darrick J. Wong
Browse files

xfs: Check for extent overflow when adding/removing xattrs 



Adding/removing an xattr can cause XFS_DA_NODE_MAXDEPTH extents to be
added. One extra extent for dabtree in case a local attr is large enough
to cause a double split.  It can also cause extent count to increase
proportional to the size of a remote xattr's value.

Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarAllison Henderson <allison.henderson@oracle.com>
Signed-off-by: default avatarChandan Babu R <chandanrlinux@gmail.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
parent 02092a2f

fs/xfs/libxfs/xfs_attr.c

+13 −0
Original line number Diff line number Diff line
@@ -396,6 +396,7 @@ xfs_attr_set( 
	struct xfs_trans_res	tres;

	bool			rsvd = (args->attr_filter & XFS_ATTR_ROOT);

	int			error, local;

	int			rmt_blks = 0;

	unsigned int		total;



	if (XFS_FORCED_SHUTDOWN(dp->i_mount))
@@ -442,11 +443,15 @@ xfs_attr_set( 
		tres.tr_logcount = XFS_ATTRSET_LOG_COUNT;

		tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;

		total = args->total;



		if (!local)

			rmt_blks = xfs_attr3_rmt_blocks(mp, args->valuelen);

	} else {

		XFS_STATS_INC(mp, xs_attr_remove);



		tres = M_RES(mp)->tr_attrrm;

		total = XFS_ATTRRM_SPACE_RES(mp);

		rmt_blks = xfs_attr3_rmt_blocks(mp, XFS_XATTR_SIZE_MAX);

	}



	/*
@@ -460,6 +465,14 @@ xfs_attr_set( 


	xfs_ilock(dp, XFS_ILOCK_EXCL);

	xfs_trans_ijoin(args->trans, dp, 0);



	if (args->value || xfs_inode_hasattr(dp)) {

		error = xfs_iext_count_may_overflow(dp, XFS_ATTR_FORK,

				XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));

		if (error)

			goto out_trans_cancel;

	}



	if (args->value) {

		unsigned int	quota_flags = XFS_QMOPT_RES_REGBLKS;

fs/xfs/libxfs/xfs_inode_fork.h

+10 −0
Original line number Diff line number Diff line
@@ -60,6 +60,16 @@ struct xfs_ifork { 
#define XFS_IEXT_DIR_MANIP_CNT(mp) \

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



/*

 * Adding/removing an xattr can cause XFS_DA_NODE_MAXDEPTH extents to

 * be added. One extra extent for dabtree in case a local attr is

 * large enough to cause a double split.  It can also cause extent

 * count to increase proportional to the size of a remote xattr's

 * value.

 */

#define XFS_IEXT_ATTR_MANIP_CNT(rmt_blks) \

	(XFS_DA_NODE_MAXDEPTH + max(1, rmt_blks))



/*

 * Fork handling.

 */