Write hints applied with F_SET_RW_HINT on a block device affect the
block device inode only. Propagate these hints to the inode associated
with struct block_device because that is the inode used when writing
back dirty pages.
Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: Jens Axboe <axboe@xxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Jeff Layton <jlayton@xxxxxxxxxx>
Cc: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
fs/fcntl.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/fs/fcntl.c b/fs/fcntl.c
index fc73c5fae43c..cfb52c3a4577 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -319,6 +319,17 @@ static long fcntl_set_rw_hint(struct file *file, unsigned int cmd,
inode->i_write_hint = hint;
inode_unlock(inode);
+ /*
+ * file->f_mapping->host may differ from inode. As an example,
+ * blkdev_open() modifies file->f_mapping.
+ */
+ if (file->f_mapping->host != inode) {
+ inode = file->f_mapping->host;
+ inode_lock(inode);
+ inode->i_write_hint = hint;
+ inode_unlock(inode);
+ }
+
return 0;
}
