Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

[linux-2.6-block.git] / drivers / staging / lustre / lustre / llite / statahead.c

diff --git a/drivers/staging/lustre/lustre/llite/statahead.c b/drivers/staging/lustre/lustre/llite/statahead.c
index 5537254d469e02f018b8543c3e1030af6dbbfff5..7f8071242f23446b48d2e5d81df205302454f005 100644 (file)
--- a/drivers/staging/lustre/lustre/llite/statahead.c
+++ b/drivers/staging/lustre/lustre/llite/statahead.c
@@ -84,7 +84,7 @@ struct ll_sa_entry {
        struct qstr          se_qstr;
 };
 
-static unsigned int sai_generation = 0;
+static unsigned int sai_generation;
 static DEFINE_SPINLOCK(sai_generation_lock);
 
 static inline int ll_sa_entry_unhashed(struct ll_sa_entry *entry)
@@ -706,11 +706,21 @@ static int ll_statahead_interpret(struct ptlrpc_request *req,
        struct ll_inode_info     *lli = ll_i2info(dir);
        struct ll_statahead_info *sai = NULL;
        struct ll_sa_entry       *entry;
+       __u64                     handle = 0;
        int                    wakeup;
 
        if (it_disposition(it, DISP_LOOKUP_NEG))
                rc = -ENOENT;
 
+       if (rc == 0) {
+               /* release ibits lock ASAP to avoid deadlock when statahead
+                * thread enqueues lock on parent in readdir and another
+                * process enqueues lock on child with parent lock held, eg.
+                * unlink. */
+               handle = it->d.lustre.it_lock_handle;
+               ll_intent_drop_lock(it);
+       }
+
        spin_lock(&lli->lli_sa_lock);
        /* stale entry */
        if (unlikely(lli->lli_sai == NULL ||
@@ -745,8 +755,7 @@ static int ll_statahead_interpret(struct ptlrpc_request *req,
                         * when statahead thread tries to enqueue lock on parent
                         * for readpage and other tries to enqueue lock on child
                         * with parent's lock held, for example: unlink. */
-                       entry->se_handle = it->d.lustre.it_lock_handle;
-                       ll_intent_drop_lock(it);
+                       entry->se_handle = handle;
                        wakeup = sa_received_empty(sai);
                        list_add_tail(&entry->se_list,
                                          &sai->sai_entries_received);