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NFSv4: Fix a sleep in atomic context in nfs4_callback_sequence()

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We must drop the lock before we can sleep in referring_call_exists().

Reported-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Fixes: 045d2a6d07 ("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>
This commit is contained in:
Trond Myklebust 2018-08-14 17:55:56 -04:00 committed by Anna Schumaker
parent d0fbb1d8a1
commit 8618289c46
1 changed files with 10 additions and 4 deletions
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14
fs/nfs/callback_proc.c
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@ -442,11 +442,14 @@ validate_seqid(const struct nfs4_slot_table *tbl, const struct nfs4_slot *slot,
* 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;
@ -469,8 +472,10 @@ static bool referring_call_exists(struct nfs_client *clp,
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;
}
@ -547,7 +552,8 @@ __be32 nfs4_callback_sequence(void *argp, void *resp,
* 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;
}