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-rw-r--r--fs/xfs/linux-2.6/xfs_buf.c66
-rw-r--r--fs/xfs/linux-2.6/xfs_buf.h3
2 files changed, 51 insertions, 18 deletions
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c
index f43689754dae..e6340906342c 100644
--- a/fs/xfs/linux-2.6/xfs_buf.c
+++ b/fs/xfs/linux-2.6/xfs_buf.c
@@ -590,8 +590,10 @@ found:
PB_SET_OWNER(pb);
}
- if (pb->pb_flags & PBF_STALE)
+ if (pb->pb_flags & PBF_STALE) {
+ ASSERT((pb->pb_flags & _PBF_DELWRI_Q) == 0);
pb->pb_flags &= PBF_MAPPED;
+ }
PB_TRACE(pb, "got_lock", 0);
XFS_STATS_INC(pb_get_locked);
return (pb);
@@ -872,6 +874,17 @@ pagebuf_rele(
PB_TRACE(pb, "rele", pb->pb_relse);
+ /*
+ * pagebuf_lookup buffers are not hashed, not delayed write,
+ * and don't have their own release routines. Special case.
+ */
+ if (unlikely(!hash)) {
+ ASSERT(!pb->pb_relse);
+ if (atomic_dec_and_test(&pb->pb_hold))
+ xfs_buf_free(pb);
+ return;
+ }
+
if (atomic_dec_and_lock(&pb->pb_hold, &hash->bh_lock)) {
int do_free = 1;
@@ -883,22 +896,23 @@ pagebuf_rele(
do_free = 0;
}
- if (pb->pb_flags & PBF_DELWRI) {
- pb->pb_flags |= PBF_ASYNC;
- atomic_inc(&pb->pb_hold);
- pagebuf_delwri_queue(pb, 0);
- do_free = 0;
- } else if (pb->pb_flags & PBF_FS_MANAGED) {
+ if (pb->pb_flags & PBF_FS_MANAGED) {
do_free = 0;
}
if (do_free) {
+ ASSERT((pb->pb_flags & (PBF_DELWRI|_PBF_DELWRI_Q)) == 0);
list_del_init(&pb->pb_hash_list);
spin_unlock(&hash->bh_lock);
pagebuf_free(pb);
} else {
spin_unlock(&hash->bh_lock);
}
+ } else {
+ /*
+ * Catch reference count leaks
+ */
+ ASSERT(atomic_read(&pb->pb_hold) >= 0);
}
}
@@ -976,13 +990,24 @@ pagebuf_lock(
* pagebuf_unlock
*
* pagebuf_unlock releases the lock on the buffer object created by
- * pagebuf_lock or pagebuf_cond_lock (not any
- * pinning of underlying pages created by pagebuf_pin).
+ * pagebuf_lock or pagebuf_cond_lock (not any pinning of underlying pages
+ * created by pagebuf_pin).
+ *
+ * If the buffer is marked delwri but is not queued, do so before we
+ * unlock the buffer as we need to set flags correctly. We also need to
+ * take a reference for the delwri queue because the unlocker is going to
+ * drop their's and they don't know we just queued it.
*/
void
pagebuf_unlock( /* unlock buffer */
xfs_buf_t *pb) /* buffer to unlock */
{
+ if ((pb->pb_flags & (PBF_DELWRI|_PBF_DELWRI_Q)) == PBF_DELWRI) {
+ atomic_inc(&pb->pb_hold);
+ pb->pb_flags |= PBF_ASYNC;
+ pagebuf_delwri_queue(pb, 0);
+ }
+
PB_CLEAR_OWNER(pb);
up(&pb->pb_sema);
PB_TRACE(pb, "unlock", 0);
@@ -1486,6 +1511,11 @@ again:
ASSERT(btp == bp->pb_target);
if (!(bp->pb_flags & PBF_FS_MANAGED)) {
spin_unlock(&hash->bh_lock);
+ /*
+ * Catch superblock reference count leaks
+ * immediately
+ */
+ BUG_ON(bp->pb_bn == 0);
delay(100);
goto again;
}
@@ -1661,17 +1691,20 @@ pagebuf_delwri_queue(
int unlock)
{
PB_TRACE(pb, "delwri_q", (long)unlock);
- ASSERT(pb->pb_flags & PBF_DELWRI);
+ ASSERT((pb->pb_flags & (PBF_DELWRI|PBF_ASYNC)) ==
+ (PBF_DELWRI|PBF_ASYNC));
spin_lock(&pbd_delwrite_lock);
/* If already in the queue, dequeue and place at tail */
if (!list_empty(&pb->pb_list)) {
+ ASSERT(pb->pb_flags & _PBF_DELWRI_Q);
if (unlock) {
atomic_dec(&pb->pb_hold);
}
list_del(&pb->pb_list);
}
+ pb->pb_flags |= _PBF_DELWRI_Q;
list_add_tail(&pb->pb_list, &pbd_delwrite_queue);
pb->pb_queuetime = jiffies;
spin_unlock(&pbd_delwrite_lock);
@@ -1688,10 +1721,11 @@ pagebuf_delwri_dequeue(
spin_lock(&pbd_delwrite_lock);
if ((pb->pb_flags & PBF_DELWRI) && !list_empty(&pb->pb_list)) {
+ ASSERT(pb->pb_flags & _PBF_DELWRI_Q);
list_del_init(&pb->pb_list);
dequeued = 1;
}
- pb->pb_flags &= ~PBF_DELWRI;
+ pb->pb_flags &= ~(PBF_DELWRI|_PBF_DELWRI_Q);
spin_unlock(&pbd_delwrite_lock);
if (dequeued)
@@ -1770,7 +1804,7 @@ xfsbufd(
break;
}
- pb->pb_flags &= ~PBF_DELWRI;
+ pb->pb_flags &= ~(PBF_DELWRI|_PBF_DELWRI_Q);
pb->pb_flags |= PBF_WRITE;
list_move(&pb->pb_list, &tmp);
}
@@ -1820,15 +1854,13 @@ xfs_flush_buftarg(
if (pb->pb_target != target)
continue;
- ASSERT(pb->pb_flags & PBF_DELWRI);
+ ASSERT(pb->pb_flags & (PBF_DELWRI|_PBF_DELWRI_Q));
PB_TRACE(pb, "walkq2", (long)pagebuf_ispin(pb));
if (pagebuf_ispin(pb)) {
pincount++;
continue;
}
- pb->pb_flags &= ~PBF_DELWRI;
- pb->pb_flags |= PBF_WRITE;
list_move(&pb->pb_list, &tmp);
}
spin_unlock(&pbd_delwrite_lock);
@@ -1837,12 +1869,14 @@ xfs_flush_buftarg(
* Dropped the delayed write list lock, now walk the temporary list
*/
list_for_each_entry_safe(pb, n, &tmp, pb_list) {
+ pagebuf_lock(pb);
+ pb->pb_flags &= ~(PBF_DELWRI|_PBF_DELWRI_Q);
+ pb->pb_flags |= PBF_WRITE;
if (wait)
pb->pb_flags &= ~PBF_ASYNC;
else
list_del_init(&pb->pb_list);
- pagebuf_lock(pb);
pagebuf_iostrategy(pb);
}
diff --git a/fs/xfs/linux-2.6/xfs_buf.h b/fs/xfs/linux-2.6/xfs_buf.h
index c322e9d71f3d..4b7fe3b5e460 100644
--- a/fs/xfs/linux-2.6/xfs_buf.h
+++ b/fs/xfs/linux-2.6/xfs_buf.h
@@ -89,6 +89,7 @@ typedef enum page_buf_flags_e { /* pb_flags values */
_PBF_PAGE_CACHE = (1 << 17),/* backed by pagecache */
_PBF_KMEM_ALLOC = (1 << 18),/* backed by kmem_alloc() */
_PBF_RUN_QUEUES = (1 << 19),/* run block device task queue */
+ _PBF_DELWRI_Q = (1 << 21), /* buffer on delwri queue */
} page_buf_flags_t;
#define PBF_UPDATE (PBF_READ | PBF_WRITE)
@@ -337,8 +338,6 @@ extern void pagebuf_trace(
-
-
/* These are just for xfs_syncsub... it sets an internal variable
* then passes it to VOP_FLUSH_PAGES or adds the flags to a newly gotten buf_t
*/
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