staging: lustre: statahead: set sai_index_wait with lli_sa_lock held

It is the sponsor thread of the statahead thread to update the
sai::sai_index_wait. Originally, it didn't hold the lli_sa_lock
when did that. Becuase of out-of-order execution others may miss
to wakeup such thread.

On the other hand, if the statahead RPC gets failure, it should
wakeup the sponsor thread, not the statahead thread.

Signed-off-by: Li Xi <lixi@ddn.com>
Signed-off-by: Fan Yong <fan.yong@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-7828
Reviewed-on: http://review.whamcloud.com/18499
Reviewed-by: Lai Siyao <lai.siyao@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/lustre/lustre/llite/statahead.c b/drivers/staging/lustre/lustre/llite/statahead.c
index b43955f097ab6873c84de8896d62d874ae82608e..4769a2230ae1cdcb05b904fe7284de471c2216d1 100644 (file)
--- a/drivers/staging/lustre/lustre/llite/statahead.c
+++ b/drivers/staging/lustre/lustre/llite/statahead.c
@@ -659,8 +659,8 @@ static int ll_statahead_interpret(struct ptlrpc_request *req,
        struct ll_inode_info     *lli = ll_i2info(dir);
        struct ll_statahead_info *sai = lli->lli_sai;
        struct sa_entry *entry = (struct sa_entry *)minfo->mi_cbdata;
+       wait_queue_head_t *waitq = NULL;
        __u64 handle = 0;
-       bool wakeup;
 
        if (it_disposition(it, DISP_LOOKUP_NEG))
                rc = -ENOENT;
@@ -693,7 +693,8 @@ static int ll_statahead_interpret(struct ptlrpc_request *req,
 
        spin_lock(&lli->lli_sa_lock);
        if (rc) {
-               wakeup = __sa_make_ready(sai, entry, rc);
+               if (__sa_make_ready(sai, entry, rc))
+                       waitq = &sai->sai_waitq;
        } else {
                entry->se_minfo = minfo;
                entry->se_req = ptlrpc_request_addref(req);
@@ -704,13 +705,15 @@ static int ll_statahead_interpret(struct ptlrpc_request *req,
                 * with parent's lock held, for example: unlink.
                 */
                entry->se_handle = handle;
-               wakeup = !sa_has_callback(sai);
+               if (!sa_has_callback(sai))
+                       waitq = &sai->sai_thread.t_ctl_waitq;
+
                list_add_tail(&entry->se_list, &sai->sai_interim_entries);
        }
        sai->sai_replied++;
 
-       if (wakeup)
-               wake_up(&sai->sai_thread.t_ctl_waitq);
+       if (waitq)
+               wake_up(waitq);
        spin_unlock(&lli->lli_sa_lock);
 
        return rc;
@@ -1397,10 +1400,10 @@ static int revalidate_statahead_dentry(struct inode *dir,
                                       struct dentry **dentryp,
                                       bool unplug)
 {
+       struct ll_inode_info *lli = ll_i2info(dir);
        struct sa_entry *entry = NULL;
        struct l_wait_info lwi = { 0 };
        struct ll_dentry_data *ldd;
-       struct ll_inode_info *lli;
        int rc = 0;
 
        if ((*dentryp)->d_name.name[0] == '.') {
@@ -1446,7 +1449,9 @@ static int revalidate_statahead_dentry(struct inode *dir,
                sa_handle_callback(sai);
 
        if (!sa_ready(entry)) {
+               spin_lock(&lli->lli_sa_lock);
                sai->sai_index_wait = entry->se_index;
+               spin_unlock(&lli->lli_sa_lock);
                lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(30), NULL,
                                       LWI_ON_SIGNAL_NOOP, NULL);
                rc = l_wait_event(sai->sai_waitq, sa_ready(entry), &lwi);
@@ -1514,7 +1519,6 @@ out_unplug:
         * dentry_may_statahead().
         */
        ldd = ll_d2d(*dentryp);
-       lli = ll_i2info(dir);
        /* ldd can be NULL if llite lookup failed. */
        if (ldd)
                ldd->lld_sa_generation = lli->lli_sa_generation;