ext2: Do not update mtime of a moved directory

One of our users is complaining that his backup tool is upset on ext2
(while it's happy on ext3, xfs, ...) because of the mtime change.

The problem is:

    mkdir foo
    mkdir bar
    mkdir foo/a

Now under ext2:
    mv foo/a foo/b

changes mtime of 'foo/a' (foo/b after the move).  That does not really
make sense and it does not happen under any other filesystem I've seen.

More complicated is:
    mv foo/a bar/a

This changes mtime of foo/a (bar/a after the move) and it makes some
sense since we had to update parent directory pointer of foo/a.  But
again, no other filesystem does this.  So after some thoughts I'd vote
for consistency and change ext2 to behave the same as other filesystems.

Do not update mtime of a moved directory.  Specs don't say anything
about it (neither that it should, nor that it should not be updated) and
other common filesystems (ext3, ext4, xfs, reiserfs, fat, ...) don't do
it.  So let's become more consistent.

Spotted by ronny.pretzsch@dfs.de, initial fix by Jörn Engel.

Reported-by: <ronny.pretzsch@dfs.de>
Cc: <hare@suse.de>
Cc: Jörn Engel <joern@logfs.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ext2/dir.c b/fs/ext2/dir.c
index 003500498c22e0113fd3f019b0b62480bcd6662b..6cde970b0a1a04fae6b58aec7600491800078333 100644 (file)
--- a/fs/ext2/dir.c
+++ b/fs/ext2/dir.c
@@ -450,7 +450,7 @@ ino_t ext2_inode_by_name(struct inode *dir, struct qstr *child)
 
 /* Releases the page */
 void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
-                       struct page *page, struct inode *inode)
+                  struct page *page, struct inode *inode, int update_times)
 {
        loff_t pos = page_offset(page) +
                        (char *) de - (char *) page_address(page);
@@ -465,7 +465,8 @@ void ext2_set_link(struct inode *dir, struct ext2_dir_entry_2 *de,
        ext2_set_de_type(de, inode);
        err = ext2_commit_chunk(page, pos, len);
        ext2_put_page(page);
-       dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
+       if (update_times)
+               dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
        EXT2_I(dir)->i_flags &= ~EXT2_BTREE_FL;
        mark_inode_dirty(dir);
 }

diff --git a/fs/ext2/ext2.h b/fs/ext2/ext2.h
index f2e5811936d07c23f9cdcb8565184fbd6769cb74..d988a718aedbad0cbabd35eb73accab9213f1adc 100644 (file)
--- a/fs/ext2/ext2.h
+++ b/fs/ext2/ext2.h
@@ -111,7 +111,7 @@ extern struct ext2_dir_entry_2 * ext2_find_entry (struct inode *,struct qstr *,
 extern int ext2_delete_entry (struct ext2_dir_entry_2 *, struct page *);
 extern int ext2_empty_dir (struct inode *);
 extern struct ext2_dir_entry_2 * ext2_dotdot (struct inode *, struct page **);
-extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *);
+extern void ext2_set_link(struct inode *, struct ext2_dir_entry_2 *, struct page *, struct inode *, int);
 
 /* ialloc.c */
 extern struct inode * ext2_new_inode (struct inode *, int);

diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c
index 90ea17998a7390afa2cb9bb03ffc14d440f6a51e..6524ecaebb7a6fe6910587026c5f8039b1a1f88c 100644 (file)
--- a/fs/ext2/namei.c
+++ b/fs/ext2/namei.c
@@ -320,7 +320,7 @@ static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
                if (!new_de)
                        goto out_dir;
                inode_inc_link_count(old_inode);
-               ext2_set_link(new_dir, new_de, new_page, old_inode);
+               ext2_set_link(new_dir, new_de, new_page, old_inode, 1);
                new_inode->i_ctime = CURRENT_TIME_SEC;
                if (dir_de)
                        drop_nlink(new_inode);
@@ -352,7 +352,8 @@ static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry,
        inode_dec_link_count(old_inode);
 
        if (dir_de) {
-               ext2_set_link(old_inode, dir_de, dir_page, new_dir);
+               if (old_dir != new_dir)
+                       ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0);
                inode_dec_link_count(old_dir);
        }
        return 0;