xfs: don't allow overly small or large realtime volumes

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@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Darrick J. Wong 2023-12-01 09:24:18 -08:00
parent cf8f0e6c14
commit e14293803f
3 changed files with 17 additions and 1 deletions

View File

@ -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)
{

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@ -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,

View File

@ -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;