ceph: use i_size_{read,write} to get/set i_size

Cap message from MDS can update i_size. In that case, we don't
hold i_mutex. So it's unsafe to directly access inode->i_size
while holding i_mutex.

Signed-off-by: Yan, Zheng <zyan@redhat.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
index 6dfff0ba4d98..c22213789090 100644
--- a/fs/ceph/addr.c
+++ b/fs/ceph/addr.c
@@ -1108,7 +1108,7 @@ retry_locked:
                 return 0;
 
         /* past end of file? */
-        i_size = inode->i_size;   /* caller holds i_mutex */
+        i_size = i_size_read(inode);
 
         if (page_off >= i_size ||
             (pos_in_page == 0 && (pos+len) >= i_size &&
@@ -1183,8 +1183,7 @@ static int ceph_write_end(struct file *file, struct address_space *mapping,
                 zero_user_segment(page, from+copied, len);
 
         /* did file size increase? */
-        /* (no need for i_size_read(); we caller holds i_mutex */
-        if (pos+copied > inode->i_size)
+        if (pos+copied > i_size_read(inode))
                 check_cap = ceph_inode_set_size(inode, pos+copied);
 
         if (!PageUptodate(page))