This is a note to let you know that I've just added the patch titled
pNFS: Fix post-layoutget error handling in pnfs_update_layout()
to the 4.7-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:
pnfs-fix-post-layoutget-error-handling-in-pnfs_update_layout.patch
and it can be found in the queue-4.7 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 56b38a1f7c781519eef09c1668a3c97ea911f86b Mon Sep 17 00:00:00 2001
From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Date: Thu, 14 Jul 2016 18:34:12 -0400
Subject: pNFS: Fix post-layoutget error handling in pnfs_update_layout()
From: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
commit 56b38a1f7c781519eef09c1668a3c97ea911f86b upstream.
The non-retry error path is currently broken and ends up releasing the
reference to the layout twice. It also can end up clearing the
NFS_LAYOUT_FIRST_LAYOUTGET flag twice, causing a race.
In addition, the retry path will fail to decrement the plh_outstanding
counter.
Fixes: 183d9e7b112aa ("pnfs: rework LAYOUTGET retry handling")
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfs/pnfs.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)
--- a/fs/nfs/pnfs.c
+++ b/fs/nfs/pnfs.c
@@ -1645,6 +1645,7 @@ lookup_again:
lseg = send_layoutget(lo, ctx, &stateid, &arg, &timeout, gfp_flags);
trace_pnfs_update_layout(ino, pos, count, iomode, lo, lseg,
PNFS_UPDATE_LAYOUT_SEND_LAYOUTGET);
+ atomic_dec(&lo->plh_outstanding);
if (IS_ERR(lseg)) {
switch(PTR_ERR(lseg)) {
case -EBUSY:
@@ -1653,26 +1654,26 @@ lookup_again:
lseg = NULL;
/* Fallthrough */
case -EAGAIN:
- pnfs_put_layout_hdr(lo);
- if (first)
- pnfs_clear_first_layoutget(lo);
- if (lseg) {
- trace_pnfs_update_layout(ino, pos, count,
- iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
- goto lookup_again;
- }
- /* Fallthrough */
+ break;
default:
if (!nfs_error_is_fatal(PTR_ERR(lseg))) {
pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
lseg = NULL;
}
+ goto out_put_layout_hdr;
+ }
+ if (lseg) {
+ if (first)
+ pnfs_clear_first_layoutget(lo);
+ trace_pnfs_update_layout(ino, pos, count,
+ iomode, lo, lseg, PNFS_UPDATE_LAYOUT_RETRY);
+ pnfs_put_layout_hdr(lo);
+ goto lookup_again;
}
} else {
pnfs_layout_clear_fail_bit(lo, pnfs_iomode_to_fail_bit(iomode));
}
- atomic_dec(&lo->plh_outstanding);
out_put_layout_hdr:
if (first)
pnfs_clear_first_layoutget(lo);
Patches currently in stable-queue which might be from trond.myklebust@xxxxxxxxxxxxxxx are
queue-4.7/nfs-don-t-create-zero-length-requests.patch
queue-4.7/pnfs-separate-handling-of-nfs4err_layouttrylater-and-recallconflict.patch
queue-4.7/pnfs-handle-nfs4err_recallconflict-correctly-in-layoutget.patch
queue-4.7/pnfs-fix-layoutget-handling-of-nfs4err_bad_stateid-and-nfs4err_expired.patch
queue-4.7/pnfs-fix-post-layoutget-error-handling-in-pnfs_update_layout.patch
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