ext4: support simple conversion of extent-mapped inodes to use i_blocks
In order to make it simpler to test the code which support
i_blocks/indirect-mapped inodes, support the conversion of inodes
which are less than 12 blocks and which are contained in no more than
a single extent.
The primary intended use of this code is to converting freshly created
zero-length files and empty directories.
Note that the version of chattr in e2fsprogs 1.42.7 and earlier has a
check that prevents the clearing of the extent flag. A simple patch
which allows "chattr -e <file>" to work will be checked into the
e2fsprogs git repository.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 721f4d3..a07b7bc 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -83,17 +83,8 @@
if (!capable(CAP_SYS_RESOURCE))
goto flags_out;
}
- if (oldflags & EXT4_EXTENTS_FL) {
- /* We don't support clearning extent flags */
- if (!(flags & EXT4_EXTENTS_FL)) {
- err = -EOPNOTSUPP;
- goto flags_out;
- }
- } else if (flags & EXT4_EXTENTS_FL) {
- /* migrate the file */
+ if ((flags ^ oldflags) & EXT4_EXTENTS_FL)
migrate = 1;
- flags &= ~EXT4_EXTENTS_FL;
- }
if (flags & EXT4_EOFBLOCKS_FL) {
/* we don't support adding EOFBLOCKS flag */
@@ -137,8 +128,13 @@
err = ext4_change_inode_journal_flag(inode, jflag);
if (err)
goto flags_out;
- if (migrate)
- err = ext4_ext_migrate(inode);
+ if (migrate) {
+ if (flags & EXT4_EXTENTS_FL)
+ err = ext4_ext_migrate(inode);
+ else
+ err = ext4_ind_migrate(inode);
+ }
+
flags_out:
mutex_unlock(&inode->i_mutex);
mnt_drop_write_file(filp);