[PATCH V15 07/16] xfs: Check for extent overflow when adding/removing xattrs
From: Chandan Babu R <hidden>
Date: 2021-01-26 18:33:16
Subsystem:
filesystems (vfs and infrastructure), the rest, xfs filesystem · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds, Carlos Maiolino
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: Darrick J. Wong <redacted> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Henderson <redacted> Signed-off-by: Chandan Babu R <redacted> --- fs/xfs/libxfs/xfs_attr.c | 13 +++++++++++++ fs/xfs/libxfs/xfs_inode_fork.h | 10 ++++++++++ 2 files changed, 23 insertions(+)
diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index fd8e6418a0d3..be51e7068dcd 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c@@ -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;
diff --git a/fs/xfs/libxfs/xfs_inode_fork.h b/fs/xfs/libxfs/xfs_inode_fork.h
index ea1a9dd8a763..8d89838e23f8 100644
--- a/fs/xfs/libxfs/xfs_inode_fork.h
+++ b/fs/xfs/libxfs/xfs_inode_fork.h@@ -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. */
--
2.29.2