fs: fix iversion handling

Currently notify_change directly updates i_version for size updates,
which not only is counter to how all other fields are updated through
struct iattr, but also breaks XFS, which need inode updates to happen
under its own lock, and synchronized to the structure that gets written
to the log.

Remove the update in the common code, and it to btrfs and ext4,
XFS already does a proper updaste internally and currently gets a
double update with the existing code.

IMHO this is 3.13 and -stable material and should go in through the XFS
tree.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Acked-by: Jan Kara <jack@suse.cz>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

3 files changed, 10 insertions, 7 deletions

diff --git a/fs/attr.c b/fs/attr.c
index 267968d94673..5d4e59d56e85 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -202,11 +202,6 @@ int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **de
                         return -EPERM;
         }
 
-        if ((ia_valid & ATTR_SIZE) && IS_I_VERSION(inode)) {
-                if (attr->ia_size != inode->i_size)
-                        inode_inc_iversion(inode);
-        }
-
         if ((ia_valid & ATTR_MODE)) {
                 umode_t amode = attr->ia_mode;
                 /* Flag setting protected by i_mutex */
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f1a77449d032..471a4f7f4044 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4354,8 +4354,12 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr)
          * these flags set.  For all other operations the VFS set these flags
          * explicitly if it wants a timestamp update.
          */
-        if (newsize != oldsize && (!(mask & (ATTR_CTIME | ATTR_MTIME))))
-                inode->i_ctime = inode->i_mtime = current_fs_time(inode->i_sb);
+        if (newsize != oldsize) {
+                inode_inc_iversion(inode);
+                if (!(mask & (ATTR_CTIME | ATTR_MTIME)))
+                        inode->i_ctime = inode->i_mtime =
+                                current_fs_time(inode->i_sb);
+        }
 
         if (newsize > oldsize) {
                 truncate_pagecache(inode, newsize);
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 075763474118..7f0e15ebacd9 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4598,6 +4598,10 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
                         if (attr->ia_size > sbi->s_bitmap_maxbytes)
                                 return -EFBIG;
                 }
+
+                if (IS_I_VERSION(inode) && attr->ia_size != inode->i_size)
+                        inode_inc_iversion(inode);
+
                 if (S_ISREG(inode->i_mode) &&
                     (attr->ia_size < inode->i_size)) {
                         if (ext4_should_order_data(inode)) {