[PATCH 33/43] xfs: detect and repair misaligned rtinherit directory cowextsize hints

Darrick J. Wong
2024-12-13T01:18:51Z

From: Darrick J. Wong <djwong@kernel.org>

If we encounter a directory that has been configured to pass on a CoW
extent size hint to a new realtime file and the hint isn't an integer
multiple of the rt extent size, we should flag the hint for
administrative review and/or turn it off because that is a
misconfiguration.

Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
---
fs/xfs/scrub/inode.c | 26 +++++++++++++++++---------
fs/xfs/scrub/inode_repair.c | 15 +++++++++++++++
2 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/fs/xfs/scrub/inode.c b/fs/xfs/scrub/inode.c
index c7bbc3f78e90b1..db6edd5a5fe5d8 100644
--- a/fs/xfs/scrub/inode.c
+++ b/fs/xfs/scrub/inode.c
@@ -260,12 +260,7 @@ xchk_inode_extsize(
xchk_ino_set_warning(sc, ino);
}

-/*
- * Validate di_cowextsize hint.
- *
- * The rules are documented at xfs_ioctl_setattr_check_cowextsize().
- * These functions must be kept in sync with each other.
- */
+/* Validate di_cowextsize hint. */
STATIC void
xchk_inode_cowextsize(
struct xfs_scrub *sc,
@@ -276,12 +271,25 @@ xchk_inode_cowextsize(
uint64_t flags2)
{
xfs_failaddr_t fa;
+ uint32_t value = be32_to_cpu(dip->di_cowextsize);

- fa = xfs_inode_validate_cowextsize(sc->mp,
- be32_to_cpu(dip->di_cowextsize), mode, flags,
- flags2);
+ fa = xfs_inode_validate_cowextsize(sc->mp, value, mode, flags, flags2);
if (fa)
xchk_ino_set_corrupt(sc, ino);
+
+ /*
+ * XFS allows a sysadmin to change the rt extent size when adding a rt
+ * section to a filesystem after formatting. If there are any
+ * directories with cowextsize and rtinherit set, the hint could become
+ * misaligned with the new rextsize. The verifier doesn't check this,
+ * because we allow rtinherit directories even without an rt device.
+ * Flag this as an administrative warning since we will clean this up
+ * eventually.
+ */
+ if ((flags & XFS_DIFLAG_RTINHERIT) &&
+ (flags2 & XFS_DIFLAG2_COWEXTSIZE) &&
+ value % sc->mp->m_sb.sb_rextsize > 0)
+ xchk_ino_set_warning(sc, ino);
}

/* Make sure the di_flags make sense for the inode. */
diff --git a/fs/xfs/scrub/inode_repair.c b/fs/xfs/scrub/inode_repair.c
index 938a18721f3697..701baee144a66e 100644
--- a/fs/xfs/scrub/inode_repair.c
+++ b/fs/xfs/scrub/inode_repair.c
@@ -1903,6 +1903,20 @@ xrep_inode_pptr(
sizeof(struct xfs_attr_sf_hdr), true);
}

+/* Fix COW extent size hint problems. */
+STATIC void
+xrep_inode_cowextsize(
+ struct xfs_scrub *sc)
+{
+ /* Fix misaligned CoW extent size hints on a directory. */
+ if ((sc->ip->i_diflags & XFS_DIFLAG_RTINHERIT) &&
+ (sc->ip->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) &&
+ sc->ip->i_extsize % sc->mp->m_sb.sb_rextsize > 0) {
+ sc->ip->i_cowextsize = 0;
+ sc->ip->i_diflags2 &= ~XFS_DIFLAG2_COWEXTSIZE;
+ }
+}
+
/* Fix any irregularities in an inode that the verifiers don't catch. */
STATIC int
xrep_inode_problems(
@@ -1926,6 +1940,7 @@ xrep_inode_problems(
if (S_ISDIR(VFS_I(sc->ip)->i_mode))
xrep_inode_dir_size(sc);
xrep_inode_extsize(sc);
+ xrep_inode_cowextsize(sc);

trace_xrep_inode_fixed(sc);
xfs_trans_log_inode(sc->tp, sc->ip, XFS_ILOG_CORE);