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-rw-r--r--drivers/md/bcache/journal.c85
-rw-r--r--drivers/md/bcache/journal.h4
2 files changed, 67 insertions, 22 deletions
diff --git a/drivers/md/bcache/journal.c b/drivers/md/bcache/journal.c
index a1e3e1fcea6e..8bcd8f1bf8cb 100644
--- a/drivers/md/bcache/journal.c
+++ b/drivers/md/bcache/journal.c
@@ -419,47 +419,87 @@ err:
static void btree_flush_write(struct cache_set *c)
{
- /*
- * Try to find the btree node with that references the oldest journal
- * entry, best is our current candidate and is locked if non NULL:
- */
- struct btree *b, *best;
- unsigned int i;
+ struct btree *b, *t, *btree_nodes[BTREE_FLUSH_NR];
+ unsigned int i, n;
+
+ if (c->journal.btree_flushing)
+ return;
+
+ spin_lock(&c->journal.flush_write_lock);
+ if (c->journal.btree_flushing) {
+ spin_unlock(&c->journal.flush_write_lock);
+ return;
+ }
+ c->journal.btree_flushing = true;
+ spin_unlock(&c->journal.flush_write_lock);
atomic_long_inc(&c->flush_write);
-retry:
- best = NULL;
+ memset(btree_nodes, 0, sizeof(btree_nodes));
+ n = 0;
mutex_lock(&c->bucket_lock);
- for_each_cached_btree(b, c, i)
- if (btree_current_write(b)->journal) {
- if (!best)
- best = b;
- else if (journal_pin_cmp(c,
- btree_current_write(best)->journal,
- btree_current_write(b)->journal)) {
- best = b;
- }
+ list_for_each_entry_safe_reverse(b, t, &c->btree_cache, list) {
+ if (btree_node_journal_flush(b))
+ pr_err("BUG: flush_write bit should not be set here!");
+
+ mutex_lock(&b->write_lock);
+
+ if (!btree_node_dirty(b)) {
+ mutex_unlock(&b->write_lock);
+ continue;
+ }
+
+ if (!btree_current_write(b)->journal) {
+ mutex_unlock(&b->write_lock);
+ continue;
}
- b = best;
- if (b)
set_btree_node_journal_flush(b);
+
+ mutex_unlock(&b->write_lock);
+
+ btree_nodes[n++] = b;
+ if (n == BTREE_FLUSH_NR)
+ break;
+ }
mutex_unlock(&c->bucket_lock);
- if (b) {
+ for (i = 0; i < n; i++) {
+ b = btree_nodes[i];
+ if (!b) {
+ pr_err("BUG: btree_nodes[%d] is NULL", i);
+ continue;
+ }
+
+ /* safe to check without holding b->write_lock */
+ if (!btree_node_journal_flush(b)) {
+ pr_err("BUG: bnode %p: journal_flush bit cleaned", b);
+ continue;
+ }
+
mutex_lock(&b->write_lock);
if (!btree_current_write(b)->journal) {
clear_bit(BTREE_NODE_journal_flush, &b->flags);
mutex_unlock(&b->write_lock);
- /* We raced */
- goto retry;
+ pr_debug("bnode %p: written by others", b);
+ continue;
+ }
+
+ if (!btree_node_dirty(b)) {
+ clear_bit(BTREE_NODE_journal_flush, &b->flags);
+ mutex_unlock(&b->write_lock);
+ pr_debug("bnode %p: dirty bit cleaned by others", b);
+ continue;
}
__bch_btree_node_write(b, NULL);
clear_bit(BTREE_NODE_journal_flush, &b->flags);
mutex_unlock(&b->write_lock);
}
+
+ spin_lock(&c->journal.flush_write_lock);
+ c->journal.btree_flushing = false;
+ spin_unlock(&c->journal.flush_write_lock);
}
#define last_seq(j) ((j)->seq - fifo_used(&(j)->pin) + 1)
@@ -881,6 +921,7 @@ int bch_journal_alloc(struct cache_set *c)
struct journal *j = &c->journal;
spin_lock_init(&j->lock);
+ spin_lock_init(&j->flush_write_lock);
INIT_DELAYED_WORK(&j->work, journal_write_work);
c->journal_delay_ms = 100;
diff --git a/drivers/md/bcache/journal.h b/drivers/md/bcache/journal.h
index 66f0facff84b..f2ea34d5f431 100644
--- a/drivers/md/bcache/journal.h
+++ b/drivers/md/bcache/journal.h
@@ -103,6 +103,8 @@ struct journal_write {
/* Embedded in struct cache_set */
struct journal {
spinlock_t lock;
+ spinlock_t flush_write_lock;
+ bool btree_flushing;
/* used when waiting because the journal was full */
struct closure_waitlist wait;
struct closure io;
@@ -154,6 +156,8 @@ struct journal_device {
struct bio_vec bv[8];
};
+#define BTREE_FLUSH_NR 8
+
#define journal_pin_cmp(c, l, r) \
(fifo_idx(&(c)->journal.pin, (l)) > fifo_idx(&(c)->journal.pin, (r)))
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