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")
Cc: stable@xxxxxxxxxxxxxxx # 4.7
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
fs/nfs/pnfs.c | 21 +++++++++++----------
1 file changed, 11 insertions(+), 10 deletions(-)
diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c
index 0fbe734cc38c..563f131c9abe 100644
--- 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 -ERECALLCONFLICT:
@@ -1652,26 +1653,26 @@ 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);
--
2.7.4
--
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