[PATCH v2] pNFS: Fix EBUSY check in pnfs_layout_need_return

[tmenninger]

From: Tim Menninger <tmenninger@xxxxxxxxxxxxxxxx>

Commit 41d0a8ead9720 ("NFSv4/pnfs: Add support for the
PNFS_LAYOUT_FILE_BULK_RETURN flag") replaced
pnfs_layout_segments_returnable() in pnfs_layout_need_return() with a
direct call to pnfs_mark_layout_stateid_return().

The old helper checked the return value against -EBUSY, but the
replacement compares against EBUSY. Since
pnfs_mark_layout_stateid_return() returns negative errno values, the
-EBUSY case is never detected.

Fix the comparison in pnfs_layout_need_return() to check against -EBUSY.

Fixes: 41d0a8ead9720 ("NFSv4/pnfs: Add support for the PNFS_LAYOUT_FILE_BULK_RETURN flag")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Tim Menninger <tmenninger@xxxxxxxxxxxxxxxx>
---
v1 -> v2:
- Preserve the -ENOENT path so the client can respond to recalls when it
  no longer holds matching layout segments, as pointed out by Trond.
- Defer only on -EBUSY instead of requiring a zero return value.

v1: https://lore.kernel.org/all/20260817154044.1799634-1-tmenninger@xxxxxxxxxxxxxxx/

 fs/nfs/pnfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 9f32dd7c4c63..594350f4ed2d 100644
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1389,7 +1389,7 @@ pnfs_layout_need_return(struct pnfs_layout_hdr *lo)
 		return false;
 	return pnfs_mark_layout_stateid_return(lo, &lo->plh_return_segs,
 					       lo->plh_return_iomode,
-					       lo->plh_return_seq) != EBUSY;
+					       lo->plh_return_seq) != -EBUSY;
 }
 
 static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
-- 
2.34.1