add releasepage hooks to block devices which can be used by file systems

Implement blkdev_releasepage() to release the buffer_heads and pages
after we release private data belonging to a mounted filesystem.

Cc: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index f2a3010140e3..0f54ae0f0ccd 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -565,6 +565,7 @@ struct address_space {
 struct block_device {
         dev_t                   bd_dev;  /* not a kdev_t - it's a search key */
         struct inode *          bd_inode;       /* will die */
+        struct super_block *    bd_super;
         int                     bd_openers;
         struct mutex            bd_mutex;       /* open/close mutex */
         struct semaphore        bd_mount_sem;
@@ -1385,6 +1386,7 @@ struct super_operations {
         ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);
         ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);
 #endif
+        int (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);
 };
 
 /*