4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Trond Myklebust <trondmy@xxxxxxxxx>
commit 8618289c46556fd4dd259a1af02ccc448032f48d upstream.
We must drop the lock before we can sleep in referring_call_exists().
Reported-by: Jia-Ju Bai <baijiaju1990@xxxxxxxxx>
Fixes: 045d2a6d076a ("NFSv4.1: Delay callback processing...")
Cc: stable@xxxxxxxxxxxxxxx # v4.9+
Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/nfs/callback_proc.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
--- a/fs/nfs/callback_proc.c
+++ b/fs/nfs/callback_proc.c
@@ -441,11 +441,14 @@ validate_seqid(const struct nfs4_slot_ta
* a match. If the slot is in use and the sequence numbers match, the
* client is still waiting for a response to the original request.
*/
-static bool referring_call_exists(struct nfs_client *clp,
+static int referring_call_exists(struct nfs_client *clp,
uint32_t nrclists,
- struct referring_call_list *rclists)
+ struct referring_call_list *rclists,
+ spinlock_t *lock)
+ __releases(lock)
+ __acquires(lock)
{
- bool status = false;
+ int status = 0;
int i, j;
struct nfs4_session *session;
struct nfs4_slot_table *tbl;
@@ -468,8 +471,10 @@ static bool referring_call_exists(struct
for (j = 0; j < rclist->rcl_nrefcalls; j++) {
ref = &rclist->rcl_refcalls[j];
+ spin_unlock(lock);
status = nfs4_slot_wait_on_seqid(tbl, ref->rc_slotid,
ref->rc_sequenceid, HZ >> 1) < 0;
+ spin_lock(lock);
if (status)
goto out;
}
@@ -546,7 +551,8 @@ __be32 nfs4_callback_sequence(void *argp
* related callback was received before the response to the original
* call.
*/
- if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists)) {
+ if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists,
+ &tbl->slot_tbl_lock) < 0) {
status = htonl(NFS4ERR_DELAY);
goto out_unlock;
}
