Merge branch 'akpm' (patches from Andrew)

[linux-2.6-microblaze.git] / fs / buffer.c

diff --git a/fs/buffer.c b/fs/buffer.c
index c2e052c..ea48c01 100644 (file)
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1260,6 +1260,15 @@ static void bh_lru_install(struct buffer_head *bh)
        int i;
 
        check_irqs_on();
+       /*
+        * the refcount of buffer_head in bh_lru prevents dropping the
+        * attached page(i.e., try_to_free_buffers) so it could cause
+        * failing page migration.
+        * Skip putting upcoming bh into bh_lru until migration is done.
+        */
+       if (lru_cache_disabled())
+               return;
+
        bh_lru_lock();
 
        b = this_cpu_ptr(&bh_lrus);
@@ -1400,6 +1409,15 @@ __bread_gfp(struct block_device *bdev, sector_t block,
 }
 EXPORT_SYMBOL(__bread_gfp);
 
+static void __invalidate_bh_lrus(struct bh_lru *b)
+{
+       int i;
+
+       for (i = 0; i < BH_LRU_SIZE; i++) {
+               brelse(b->bhs[i]);
+               b->bhs[i] = NULL;
+       }
+}
 /*
  * invalidate_bh_lrus() is called rarely - but not only at unmount.
  * This doesn't race because it runs in each cpu either in irq
@@ -1408,16 +1426,12 @@ EXPORT_SYMBOL(__bread_gfp);
 static void invalidate_bh_lru(void *arg)
 {
        struct bh_lru *b = &get_cpu_var(bh_lrus);
-       int i;
 
-       for (i = 0; i < BH_LRU_SIZE; i++) {
-               brelse(b->bhs[i]);
-               b->bhs[i] = NULL;
-       }
+       __invalidate_bh_lrus(b);
        put_cpu_var(bh_lrus);
 }
 
-static bool has_bh_in_lru(int cpu, void *dummy)
+bool has_bh_in_lru(int cpu, void *dummy)
 {
        struct bh_lru *b = per_cpu_ptr(&bh_lrus, cpu);
        int i;
@@ -1436,6 +1450,16 @@ void invalidate_bh_lrus(void)
 }
 EXPORT_SYMBOL_GPL(invalidate_bh_lrus);
 
+void invalidate_bh_lrus_cpu(int cpu)
+{
+       struct bh_lru *b;
+
+       bh_lru_lock();
+       b = per_cpu_ptr(&bh_lrus, cpu);
+       __invalidate_bh_lrus(b);
+       bh_lru_unlock();
+}
+
 void set_bh_page(struct buffer_head *bh,
                struct page *page, unsigned long offset)
 {