1 files changed, 44 insertions, 17 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 01c21b6c6d43..45c81bb4ac82 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -929,7 +929,8 @@ int set_extent_bit(struct extent_io_tree *tree, u64 start, u64 end, int bits,
 
 
 /**
- * convert_extent - convert all bits in a given range from one bit to another
+ * convert_extent_bit - convert all bits in a given range from one bit to
+ *                      another
  * @tree:       the io tree to search
  * @start:      the start offset in bytes
  * @end:        the end offset in bytes (inclusive)
@@ -1918,7 +1919,7 @@ int repair_io_failure(struct btrfs_mapping_tree *map_tree, u64 start,
                 return -EIO;
         }
 
-        printk_in_rcu(KERN_INFO "btrfs read error corrected: ino %lu off %llu "
+        printk_ratelimited_in_rcu(KERN_INFO "btrfs read error corrected: ino %lu off %llu "
                       "(dev %s sector %llu)\n", page->mapping->host->i_ino,
                       start, rcu_str_deref(dev->name), sector);
 
@@ -3077,8 +3078,15 @@ static int lock_extent_buffer_for_io(struct extent_buffer *eb,
                 }
         }
 
+        /*
+         * We need to do this to prevent races in people who check if the eb is
+         * under IO since we can end up having no IO bits set for a short period
+         * of time.
+         */
+        spin_lock(&eb->refs_lock);
         if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)) {
                 set_bit(EXTENT_BUFFER_WRITEBACK, &eb->bflags);
+                spin_unlock(&eb->refs_lock);
                 btrfs_set_header_flag(eb, BTRFS_HEADER_FLAG_WRITTEN);
                 spin_lock(&fs_info->delalloc_lock);
                 if (fs_info->dirty_metadata_bytes >= eb->len)
@@ -3087,6 +3095,8 @@ static int lock_extent_buffer_for_io(struct extent_buffer *eb,
                         WARN_ON(1);
                 spin_unlock(&fs_info->delalloc_lock);
                 ret = 1;
+        } else {
+                spin_unlock(&eb->refs_lock);
         }
 
         btrfs_tree_unlock(eb);
@@ -3557,19 +3567,38 @@ int extent_readpages(struct extent_io_tree *tree,
         struct bio *bio = NULL;
         unsigned page_idx;
         unsigned long bio_flags = 0;
+        struct page *pagepool[16];
+        struct page *page;
+        int i = 0;
+        int nr = 0;
 
         for (page_idx = 0; page_idx < nr_pages; page_idx++) {
-                struct page *page = list_entry(pages->prev, struct page, lru);
+                page = list_entry(pages->prev, struct page, lru);
 
                 prefetchw(&page->flags);
                 list_del(&page->lru);
-                if (!add_to_page_cache_lru(page, mapping,
+                if (add_to_page_cache_lru(page, mapping,
                                         page->index, GFP_NOFS)) {
-                        __extent_read_full_page(tree, page, get_extent,
-                                                &bio, 0, &bio_flags);
+                        page_cache_release(page);
+                        continue;
                 }
-                page_cache_release(page);
+
+                pagepool[nr++] = page;
+                if (nr < ARRAY_SIZE(pagepool))
+                        continue;
+                for (i = 0; i < nr; i++) {
+                        __extent_read_full_page(tree, pagepool[i], get_extent,
+                                        &bio, 0, &bio_flags);
+                        page_cache_release(pagepool[i]);
+                }
+                nr = 0;
+        }
+        for (i = 0; i < nr; i++) {
+                __extent_read_full_page(tree, pagepool[i], get_extent,
+                                        &bio, 0, &bio_flags);
+                page_cache_release(pagepool[i]);
         }
+
         BUG_ON(!list_empty(pages));
         if (bio)
                 return submit_one_bio(READ, bio, 0, bio_flags);
@@ -4123,11 +4152,10 @@ static void check_buffer_tree_ref(struct extent_buffer *eb)
          * So bump the ref count first, then set the bit.  If someone
          * beat us to it, drop the ref we added.
          */
-        if (!test_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags)) {
+        spin_lock(&eb->refs_lock);
+        if (!test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
                 atomic_inc(&eb->refs);
-                if (test_and_set_bit(EXTENT_BUFFER_TREE_REF, &eb->bflags))
-                        atomic_dec(&eb->refs);
-        }
+        spin_unlock(&eb->refs_lock);
 }
 
 static void mark_extent_buffer_accessed(struct extent_buffer *eb)
@@ -4239,9 +4267,7 @@ again:
                 goto free_eb;
         }
         /* add one reference for the tree */
-        spin_lock(&eb->refs_lock);
         check_buffer_tree_ref(eb);
-        spin_unlock(&eb->refs_lock);
         spin_unlock(&tree->buffer_lock);
         radix_tree_preload_end();
 
@@ -4300,7 +4326,7 @@ static inline void btrfs_release_extent_buffer_rcu(struct rcu_head *head)
 }
 
 /* Expects to have eb->eb_lock already held */
-static void release_extent_buffer(struct extent_buffer *eb, gfp_t mask)
+static int release_extent_buffer(struct extent_buffer *eb, gfp_t mask)
 {
         WARN_ON(atomic_read(&eb->refs) == 0);
         if (atomic_dec_and_test(&eb->refs)) {
@@ -4321,9 +4347,11 @@ static void release_extent_buffer(struct extent_buffer *eb, gfp_t mask)
                 btrfs_release_extent_buffer_page(eb, 0);
 
                 call_rcu(&eb->rcu_head, btrfs_release_extent_buffer_rcu);
-                return;
+                return 1;
         }
         spin_unlock(&eb->refs_lock);
+
+        return 0;
 }
 
 void free_extent_buffer(struct extent_buffer *eb)
@@ -4962,7 +4990,6 @@ int try_release_extent_buffer(struct page *page, gfp_t mask)
                 spin_unlock(&eb->refs_lock);
                 return 0;
         }
-        release_extent_buffer(eb, mask);
 
-        return 1;
+        return release_extent_buffer(eb, mask);
 }