diff mbox series

[v17,14/21] xfs: don't remove written extents past EOF on fsverity inodes

Message ID 20261002223705.2175542-15-aalbersh@kernel.org
State Not Applicable
Headers show
Series fs-verity support for XFS with post EOF merkle tree | expand

Commit Message

Andrey Albershteyn Oct. 2, 2026, 10:36 p.m. UTC 
xfs_free_eofblocks() removes all extents past EOF unless the
XFS_DIFLAG_PREALLOC or XFS_DIFLAG_APPEND flags are set. This is
undesired for fsverity as it stores metadata beyond EOF. However, while
merkle tree is being built, delayed preallocation and unwritten extents
are used. After metadata construction is done, fsverity inodes becomes
read-only and won't be changed anymore, none of these unwritten extents
or preallocations in post EOF region will be used.

Let xfs_free_eofblocks() be called on fsverity inode as usual to remove
anything which is not written extent. However, inodes which are
undergoing merkle tree construction need to be skipped in case reclaim
takes place.

Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
---
 fs/xfs/xfs_bmap_util.c | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

Comments

sashiko-bot@kernel.org Oct. 3, 2026, 1:34 a.m. UTC | #1 
> xfs_free_eofblocks() removes all extents past EOF unless the
> XFS_DIFLAG_PREALLOC or XFS_DIFLAG_APPEND flags are set. This is
> undesired for fsverity as it stores metadata beyond EOF. However, while
> merkle tree is being built, delayed preallocation and unwritten extents
> are used. After metadata construction is done, fsverity inodes becomes
> read-only and won't be changed anymore, none of these unwritten extents
> or preallocations in post EOF region will be used.
> 
> Let xfs_free_eofblocks() be called on fsverity inode as usual to remove
> anything which is not written extent. However, inodes which are
> undergoing merkle tree construction need to be skipped in case reclaim
> takes place.
> 
> Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>

Sashiko has reviewed this patch and found no issues. It looks great!
diff mbox series

Patch

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 268d159339d0..74e99d0bee7a 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -31,6 +31,7 @@ 
 #include "xfs_rtbitmap.h"
 #include "xfs_rtgroup.h"
 #include "xfs_zone_alloc.h"
+#include <linux/fsverity.h>
 
 /* Kernel only BMAP related definitions and functions */
 
@@ -553,6 +554,15 @@  xfs_can_free_eofblocks(
 	if (last_fsb <= end_fsb)
 		return false;
 
+	/*
+	 * Don't clean fsverity inodes as they already have been cleaned up and
+	 * are read-only. Skip inodes which have merkle tree being built, the
+	 * merkle tree is written beyond EOF
+	 */
+	if (fsverity_active(VFS_IC(ip)) ||
+	    xfs_iflags_test(ip, XFS_VERITY_CONSTRUCTION))
+		return false;
+
 	/*
 	 * Check if there is an post-EOF extent to free.  If there are any
 	 * delalloc blocks attached to the inode (data fork delalloc
@@ -579,6 +589,9 @@  xfs_free_eofblocks(
 	struct xfs_trans	*tp;
 	struct xfs_mount	*mp = ip->i_mount;
 	int			error;
+	int			bmapi_flags = XFS_BMAPI_NODISCARD;
+	bool			has_verity =
+			ip->i_diflags2 & XFS_DIFLAG2_VERITY;
 
 	/* Attach the dquots to the inode up front. */
 	error = xfs_qm_dqattach(ip);
@@ -593,15 +606,20 @@  xfs_free_eofblocks(
 	 *
 	 * Note that this means we also leave speculative preallocations in
 	 * place for preallocated files.
+	 *
+	 * Clean up delalloc reservations for fsverity too as those won't be
+	 * used
 	 */
-	if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)) {
+	if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND) ||
+			has_verity) {
 		if (ip->i_delayed_blks) {
 			xfs_bmap_punch_delalloc_range(ip, XFS_DATA_FORK,
 				round_up(XFS_ISIZE(ip), mp->m_sb.sb_blocksize),
 				LLONG_MAX, NULL);
 		}
 		xfs_inode_clear_eofblocks_tag(ip);
-		return 0;
+		if (!has_verity)
+			return 0;
 	}
 
 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
@@ -613,6 +631,13 @@  xfs_free_eofblocks(
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 	xfs_trans_ijoin(tp, ip, 0);
 
+	/*
+	 * While fs-verity writes metadata after EOF, it can leave unwritten
+	 * preallocations.  Clear all that out.
+	 */
+	if (has_verity)
+		bmapi_flags |= XFS_BMAPI_UNWRITTEN;
+
 	/*
 	 * Do not update the on-disk file size.  If we update the on-disk file
 	 * size and then the system crashes before the contents of the file are
@@ -620,7 +645,7 @@  xfs_free_eofblocks(
 	 * bug).
 	 */
 	error = xfs_itruncate_extents_flags(&tp, ip, XFS_DATA_FORK,
-				XFS_ISIZE(ip), XFS_BMAPI_NODISCARD);
+				XFS_ISIZE(ip), bmapi_flags);
 	if (error)
 		goto err_cancel;