ext4: make fsync to sync parent dir in no-journal for real this time

Previously commit 14ece1028b3ed53ffec1b1213ffc6acaf79ad77c added a
support for for syncing parent directory of newly created inodes to
make sure that the inode is not lost after a power failure in
no-journal mode.

However this does not work in majority of cases, namely:
 - if the directory has inline data
 - if the directory is already indexed
 - if the directory already has at least one block and:
	- the new entry fits into it
	- or we've successfully converted it to indexed

So in those cases we might lose the inode entirely even after fsync in
the no-journal mode. This also includes ext2 default mode obviously.

I've noticed this while running xfstest generic/321 and even though the
test should fail (we need to run fsck after a crash in no-journal mode)
I could not find a newly created entries even when if it was fsynced
before.

Fix this by adjusting the ext4_add_entry() successful exit paths to set
the inode EXT4_STATE_NEWENTRY so that fsync has the chance to fsync the
parent directory as well.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Frank Mayhar <fmayhar@google.com>
Cc: stable@vger.kernel.org

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index efb64ae..23a0b9b 100644 (file)
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -1864,7 +1864,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
                          struct inode *inode)
 {
        struct inode *dir = dentry->d_parent->d_inode;
-       struct buffer_head *bh;
+       struct buffer_head *bh = NULL;
        struct ext4_dir_entry_2 *de;
        struct ext4_dir_entry_tail *t;
        struct super_block *sb;
@@ -1888,14 +1888,14 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
                        return retval;
                if (retval == 1) {
                        retval = 0;
-                       return retval;
+                       goto out;
                }
        }
 
        if (is_dx(dir)) {
                retval = ext4_dx_add_entry(handle, dentry, inode);
                if (!retval || (retval != ERR_BAD_DX_DIR))
-                       return retval;
+                       goto out;
                ext4_clear_inode_flag(dir, EXT4_INODE_INDEX);
                dx_fallback++;
                ext4_mark_inode_dirty(handle, dir);
@@ -1907,14 +1907,15 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
                        return PTR_ERR(bh);
 
                retval = add_dirent_to_buf(handle, dentry, inode, NULL, bh);
-               if (retval != -ENOSPC) {
-                       brelse(bh);
-                       return retval;
-               }
+               if (retval != -ENOSPC)
+                       goto out;
 
                if (blocks == 1 && !dx_fallback &&
-                   EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX))
-                       return make_indexed_dir(handle, dentry, inode, bh);
+                   EXT4_HAS_COMPAT_FEATURE(sb, EXT4_FEATURE_COMPAT_DIR_INDEX)) {
+                       retval = make_indexed_dir(handle, dentry, inode, bh);
+                       bh = NULL; /* make_indexed_dir releases bh */
+                       goto out;
+               }
                brelse(bh);
        }
        bh = ext4_append(handle, dir, &block);
@@ -1930,6 +1931,7 @@ static int ext4_add_entry(handle_t *handle, struct dentry *dentry,
        }
 
        retval = add_dirent_to_buf(handle, dentry, inode, de, bh);
+out:
        brelse(bh);
        if (retval == 0)
                ext4_set_inode_state(inode, EXT4_STATE_NEWENTRY);