From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	"Darrick J. Wong" <djwong@kernel.org>,
	Christoph Hellwig <hch@lst.de>,
	Carlos Maiolino <cem@kernel.org>
Subject: [PATCH 6.18 1126/1250] xfs: actually recover intended file sizes in xfs_xmi_item_recover_intent
Date: Thu, 17 Sep 2026 16:15:21 +0100
Message-ID: <20260917151622.763398031@linuxfoundation.org>
In-Reply-To: <20260917151551.901433442@linuxfoundation.org>
References: <20260917151551.901433442@linuxfoundation.org>
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6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Darrick J. Wong <djwong@kernel.org>

commit b71ae66863e4320a3b7313b53bb4d65f1718d58b upstream.

LOLLM points out that xfs_xmi_item_recover_intent doesn't actually
restore the isize1 and isize2 fields that were recovered from an
unfinished exchmaps log intent item.  Instead, xfs_exchmaps_init_intent
sets the wrong isize values from the recovered inodes, with the result
that the file sizes are not set correctly when item recovery finishes.
Fix this by restoring isize[12] from the log item.

Cc: stable@vger.kernel.org # v6.10
Fixes: 966ceafc7a4371 ("xfs: create deferred log items for file mapping exchanges")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Assisted-by: LOLLM # finding obvious bugs
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 fs/xfs/xfs_exchmaps_item.c |   19 ++++++++++++++++++-
 1 file changed, 18 insertions(+), 1 deletion(-)

--- a/fs/xfs/xfs_exchmaps_item.c
+++ b/fs/xfs/xfs_exchmaps_item.c
@@ -347,7 +347,17 @@ xfs_xmi_validate(
 	if (!xfs_verify_fileext(mp, xlf->xmi_startoff1, xlf->xmi_blockcount))
 		return false;
 
-	return xfs_verify_fileext(mp, xlf->xmi_startoff2, xlf->xmi_blockcount);
+	if (!xfs_verify_fileext(mp, xlf->xmi_startoff2, xlf->xmi_blockcount))
+		return false;
+
+	if (xlf->xmi_flags & XFS_EXCHMAPS_SET_SIZES) {
+		if ((int64_t)xlf->xmi_isize1 < 0)
+			return false;
+		if ((int64_t)xlf->xmi_isize2 < 0)
+			return false;
+	}
+
+	return true;
 }
 
 /*
@@ -406,6 +416,13 @@ xfs_xmi_item_recover_intent(
 	*ipp1 = ip1;
 	*ipp2 = ip2;
 	xmi = xfs_exchmaps_init_intent(req);
+
+	/* Restore intended file sizes from recovered logged item */
+	if (req->flags & XFS_EXCHMAPS_SET_SIZES) {
+		xmi->xmi_isize1 = xlf->xmi_isize1;
+		xmi->xmi_isize2 = xlf->xmi_isize2;
+	}
+
 	xfs_defer_add_item(dfp, &xmi->xmi_list);
 	return xmi;