Btrfs: don't return true in releasepage unless we actually freed the eb

[karo-tx-linux.git] / fs / buffer.c

diff --git a/fs/buffer.c b/fs/buffer.c
index 36d66653b93191c9c13c21e74dea6f511a6ac9ab..c7062c896d7c20489f41ea838640a5cfa5387ca9 100644 (file)
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -921,6 +921,7 @@ init_page_buffers(struct page *page, struct block_device *bdev,
        struct buffer_head *head = page_buffers(page);
        struct buffer_head *bh = head;
        int uptodate = PageUptodate(page);
+       sector_t end_block = blkdev_max_block(I_BDEV(bdev->bd_inode));
 
        do {
                if (!buffer_mapped(bh)) {
@@ -929,7 +930,8 @@ init_page_buffers(struct page *page, struct block_device *bdev,
                        bh->b_blocknr = block;
                        if (uptodate)
                                set_buffer_uptodate(bh);
-                       set_buffer_mapped(bh);
+                       if (block < end_block)
+                               set_buffer_mapped(bh);
                }
                block++;
                bh = bh->b_this_page;
@@ -985,7 +987,6 @@ grow_dev_page(struct block_device *bdev, sector_t block,
        return page;
 
 failed:
-       BUG();
        unlock_page(page);
        page_cache_release(page);
        return NULL;
@@ -1035,6 +1036,9 @@ grow_buffers(struct block_device *bdev, sector_t block, int size)
 static struct buffer_head *
 __getblk_slow(struct block_device *bdev, sector_t block, int size)
 {
+       int ret;
+       struct buffer_head *bh;
+
        /* Size must be multiple of hard sectorsize */
        if (unlikely(size & (bdev_logical_block_size(bdev)-1) ||
                        (size < 512 || size > PAGE_SIZE))) {
@@ -1047,20 +1051,21 @@ __getblk_slow(struct block_device *bdev, sector_t block, int size)
                return NULL;
        }
 
-       for (;;) {
-               struct buffer_head * bh;
-               int ret;
+retry:
+       bh = __find_get_block(bdev, block, size);
+       if (bh)
+               return bh;
 
+       ret = grow_buffers(bdev, block, size);
+       if (ret == 0) {
+               free_more_memory();
+               goto retry;
+       } else if (ret > 0) {
                bh = __find_get_block(bdev, block, size);
                if (bh)
                        return bh;
-
-               ret = grow_buffers(bdev, block, size);
-               if (ret < 0)
-                       return NULL;
-               if (ret == 0)
-                       free_more_memory();
        }
+       return NULL;
 }
 
 /*
@@ -3151,7 +3156,7 @@ SYSCALL_DEFINE2(bdflush, int, func, long, data)
 /*
  * Buffer-head allocation
  */
-static struct kmem_cache *bh_cachep;
+static struct kmem_cache *bh_cachep __read_mostly;
 
 /*
  * Once the number of bh's in the machine exceeds this level, we start