Patch "xfs: fix 32-bit truncation in xfs_compute_rextslog" 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: fix 32-bit truncation in xfs_compute_rextslog

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-fix-32-bit-truncation-in-xfs_compute_rextslog.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 21:26:35 2025
From: Leah Rumancik <[email protected]>
Date: Thu, 13 Mar 2025 13:25:38 -0700
Subject: xfs: fix 32-bit truncation in xfs_compute_rextslog
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 cf8f0e6c1429be7652869059ea44696b72d5b726 ]

It's quite reasonable that some customer somewhere will want to
configure a realtime volume with more than 2^32 extents.  If they try to
do this, the highbit32() call will truncate the upper bits of the
xfs_rtbxlen_t and produce the wrong value for rextslog.  This in turn
causes the rsumlevels to be wrong, which results in a realtime summary
file that is the wrong length.  Fix that.

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.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/fs/xfs/libxfs/xfs_rtbitmap.c
+++ b/fs/xfs/libxfs/xfs_rtbitmap.c
@@ -1133,13 +1133,15 @@ xfs_rtalloc_extent_is_free(
 
 /*
  * Compute the maximum level number of the realtime summary file, as defined by
- * mkfs.  The use of highbit32 on a 64-bit quantity is a historic artifact that
- * prohibits correct use of rt volumes with more than 2^32 extents.
+ * mkfs.  The historic use of highbit32 on a 64-bit quantity prohibited correct
+ * use of rt volumes with more than 2^32 extents.
  */
 uint8_t
 xfs_compute_rextslog(
 	xfs_rtbxlen_t		rtextents)
 {
-	return rtextents ? xfs_highbit32(rtextents) : 0;
+	if (!rtextents)
+		return 0;
+	return xfs_highbit64(rtextents);
 }
 


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