4.18-stable review patch. If anyone has any objections, please let me know.
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From: Trond Myklebust trondmy@gmail.com
commit 8618289c46556fd4dd259a1af02ccc448032f48d upstream.
We must drop the lock before we can sleep in referring_call_exists().
Reported-by: Jia-Ju Bai baijiaju1990@gmail.com Fixes: 045d2a6d076a ("NFSv4.1: Delay callback processing...") Cc: stable@vger.kernel.org # v4.9+ Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Anna Schumaker Anna.Schumaker@Netapp.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- 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; }