[PATCH] 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") changed pnfs_layout_need_return() to
check whether pnfs_mark_layout_stateid_return() returns -EBUSY.

However, the new check compares the return value against EBUSY rather
than -EBUSY. Since pnfs_mark_layout_stateid_return() returns negative
errno values, the -EBUSY case is never detected.

But pnfs_layout_need_return() calls pnfs_mark_layout_stateid_return()
calls pnfs_mark_matching_lsegs_return(), which returns 0 if a
layoutreturn needs to be scheduled.

Fix the comparison in pnfs_layout_need_return() to check for 0, i.e. a
layoutreturn needs to be scheduled.

Fixes: 41d0a8ead9720 ("NFSv4/pnfs: Add support for the PNFS_LAYOUT_FILE_BULK_RETURN flag")
Signed-off-by: Tim Menninger <tmenninger@xxxxxxxxxxxxxxxx>
---
 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..fb141cef4d54 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) == 0;
 }
 
 static void pnfs_layoutreturn_before_put_layout_hdr(struct pnfs_layout_hdr *lo)
-- 
2.34.1