From e14293803f4e84eb23a417b462b56251033b5a66 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Fri, 1 Dec 2023 09:24:18 -0800 Subject: [PATCH] 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 Reviewed-by: Christoph Hellwig --- 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;