Patch "xfs: don't allow overly small or large realtime volumes" has been added to the 6.1-stable tree

This is a note to let you know that I've just added the patch titled

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

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     xfs-don-t-allow-overly-small-or-large-realtime-volumes.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


From [email protected] Thu Mar 13 21:26:36 2025
From: Leah Rumancik <[email protected]>
Date: Thu, 13 Mar 2025 13:25:39 -0700
Subject: xfs: don't allow overly small or large realtime volumes
To: [email protected]
Cc: [email protected], "Darrick J. Wong" <[email protected]>, Christoph Hellwig <[email protected]>, Leah Rumancik <[email protected]>
Message-ID: <[email protected]>

From: "Darrick J. Wong" <[email protected]>

[ Upstream commit e14293803f4e84eb23a417b462b56251033b5a66 ]

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 <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Leah Rumancik <[email protected]>
Acked-by: "Darrick J. Wong" <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 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(-)

--- a/fs/xfs/libxfs/xfs_rtbitmap.h
+++ b/fs/xfs/libxfs/xfs_rtbitmap.h
@@ -73,6 +73,18 @@ int xfs_rtfree_blocks(struct xfs_trans *
 
 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;
+}
+
 #else /* CONFIG_XFS_RT */
 # define xfs_rtfree_extent(t,b,l)			(-ENOSYS)
 # define xfs_rtfree_blocks(t,rb,rl)			(-ENOSYS)
@@ -81,6 +93,7 @@ uint8_t xfs_compute_rextslog(xfs_rtbxlen
 # define xfs_rtbuf_get(m,t,b,i,p)			(-ENOSYS)
 # define xfs_rtalloc_extent_is_free(m,t,s,l,i)		(-ENOSYS)
 # define xfs_compute_rextslog(rtx)			(0)
+# define xfs_validate_rtextents(rtx)			(false)
 #endif /* CONFIG_XFS_RT */
 
 #endif /* __XFS_RTBITMAP_H__ */
--- a/fs/xfs/libxfs/xfs_sb.c
+++ b/fs/xfs/libxfs/xfs_sb.c
@@ -502,7 +502,8 @@ 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,
--- a/fs/xfs/xfs_rtalloc.c
+++ b/fs/xfs/xfs_rtalloc.c
@@ -998,6 +998,8 @@ xfs_growfs_rt(
 	 */
 	nrextents = nrblocks;
 	do_div(nrextents, in->extsize);
+	if (!xfs_validate_rtextents(nrextents))
+		return -EINVAL;
 	nrbmblocks = howmany_64(nrextents, NBBY * sbp->sb_blocksize);
 	nrextslog = xfs_compute_rextslog(nrextents);
 	nrsumlevels = nrextslog + 1;


Patches currently in stable-queue which might be from [email protected] are

queue-6.1/xfs-fix-confusing-xfs_extent_item-variable-names.patch
queue-6.1/xfs-fix-32-bit-truncation-in-xfs_compute_rextslog.patch
queue-6.1/xfs-transfer-recovered-intent-item-ownership-in-iop_recover.patch
queue-6.1/xfs-initialise-di_crc-in-xfs_log_dinode.patch
queue-6.1/xfs-consider-minlen-sized-extents-in-xfs_rtallocate_extent_block.patch
queue-6.1/xfs-don-t-leak-recovered-attri-intent-items.patch
queue-6.1/xfs-remove-unused-fields-from-struct-xbtree_ifakeroot.patch
queue-6.1/xfs-fix-bounds-check-in-xfs_defer_agfl_block.patch
queue-6.1/xfs-ensure-logflagsp-is-initialized-in-xfs_bmap_del_extent_real.patch
queue-6.1/xfs-convert-rt-bitmap-extent-lengths-to-xfs_rtbxlen_t.patch
queue-6.1/xfs-pass-refcount-intent-directly-through-the-log-intent-code.patch
queue-6.1/xfs-fix-perag-leak-when-growfs-fails.patch
queue-6.1/xfs-pass-the-xfs_defer_pending-object-to-iop_recover.patch
queue-6.1/xfs-update-dir3-leaf-block-metadata-after-swap.patch
queue-6.1/xfs-use-deferred-frees-for-btree-block-freeing.patch
queue-6.1/xfs-make-rextslog-computation-consistent-with-mkfs.patch
queue-6.1/xfs-pass-xfs_extent_free_item-directly-through-the-log-intent-code.patch
queue-6.1/xfs-move-the-xfs_rtbitmap.c-declarations-to-xfs_rtbitmap.h.patch
queue-6.1/xfs-recompute-growfsrtfree-transaction-reservation-while-growing-rt-volume.patch
queue-6.1/xfs-reserve-less-log-space-when-recovering-log-intent-items.patch
queue-6.1/xfs-pass-the-xfs_bmbt_irec-directly-through-the-log-intent-code.patch
queue-6.1/xfs-force-all-buffers-to-be-written-during-btree-bulk-load.patch
queue-6.1/xfs-reset-xfs_attr_incomplete-filter-on-node-removal.patch
queue-6.1/xfs-add-lock-protection-when-remove-perag-from-radix-tree.patch
queue-6.1/xfs-use-xfs_defer_pending-objects-to-recover-intent-items.patch
queue-6.1/xfs-pass-per-ag-references-to-xfs_free_extent.patch
queue-6.1/xfs-validate-block-number-being-freed-before-adding-to-xefi.patch
queue-6.1/xfs-don-t-allow-overly-small-or-large-realtime-volumes.patch
queue-6.1/xfs-remove-conditional-building-of-rt-geometry-validator-functions.patch