From: Darrick J. Wong <djwong@xxxxxxxxxx>
Don't allow realtime volumes that are less than one rt extent long.
This has been broken across 4 LTS kernels with nobody noticing, so let's
just disable it.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
Reviewed-by: Christoph Hellwig <hch@xxxxxx>
---
fs/xfs/libxfs/xfs_rtbitmap.h | 13 +++++++++++++
fs/xfs/libxfs/xfs_sb.c | 3 ++-
fs/xfs/xfs_rtalloc.c | 2 ++
3 files changed, 17 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/libxfs/xfs_rtbitmap.h b/fs/xfs/libxfs/xfs_rtbitmap.h
index 6e5bae324cc3..1c84b52de3d4 100644
--- a/fs/xfs/libxfs/xfs_rtbitmap.h
+++ b/fs/xfs/libxfs/xfs_rtbitmap.h
@@ -353,6 +353,18 @@ int xfs_rtfree_blocks(struct xfs_trans *tp, xfs_fsblock_t rtbno,
uint8_t xfs_compute_rextslog(xfs_rtbxlen_t rtextents);
+/* Do we support an rt volume having this number of rtextents? */
+static inline bool
+xfs_validate_rtextents(
+ xfs_rtbxlen_t rtextents)
+{
+ /* No runt rt volumes */
+ if (rtextents == 0)
+ return false;
+
+ return true;
+}
+
xfs_filblks_t xfs_rtbitmap_blockcount(struct xfs_mount *mp, xfs_rtbxlen_t
rtextents);
unsigned long long xfs_rtbitmap_wordcount(struct xfs_mount *mp,
@@ -372,6 +384,7 @@ unsigned long long xfs_rtsummary_wordcount(struct xfs_mount *mp,
# define xfs_rtbuf_cache_relse(a) (0)
# define xfs_rtalloc_extent_is_free(m,t,s,l,i) (-ENOSYS)
# define xfs_compute_rextslog(rtx) (0)
+# define xfs_validate_rtextents(rtx) (false)
static inline xfs_filblks_t
xfs_rtbitmap_blockcount(struct xfs_mount *mp, xfs_rtbxlen_t rtextents)
{
diff --git a/fs/xfs/libxfs/xfs_sb.c b/fs/xfs/libxfs/xfs_sb.c
index df12bf82ed18..4a9e8588f4c9 100644
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -509,7 +509,8 @@ xfs_validate_sb_common(
rbmblocks = howmany_64(sbp->sb_rextents,
NBBY * sbp->sb_blocksize);
- if (sbp->sb_rextents != rexts ||
+ if (!xfs_validate_rtextents(rexts) ||
+ sbp->sb_rextents != rexts ||
sbp->sb_rextslog != xfs_compute_rextslog(rexts) ||
sbp->sb_rbmblocks != rbmblocks) {
xfs_notice(mp,
diff --git a/fs/xfs/xfs_rtalloc.c b/fs/xfs/xfs_rtalloc.c
index 7c5a50163d2d..8feb58c6241c 100644
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -963,6 +963,8 @@ xfs_growfs_rt(
*/
nrextents = nrblocks;
do_div(nrextents, in->extsize);
+ if (!xfs_validate_rtextents(nrextents))
+ return -EINVAL;
nrbmblocks = xfs_rtbitmap_blockcount(mp, nrextents);
nrextslog = xfs_compute_rextslog(nrextents);
nrsumlevels = nrextslog + 1;
