ext4: Fix estimate of # of blocks needed to write indirect-mapped files

commit d330a5befb88875a9b3d2db62f9b74dadf660b13 upstream (as of v2.6.34-rc3)

http://bugzilla.kernel.org/show_bug.cgi?id=15420

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
ext4: Fixed inode allocator to correctly track a flex_bg's used_dirs

commit c4caae25187ff3f5e837c6f04eb1acc2723c72d3 upstream (as of v2.6.34-rc3)

When used_dirs was introduced for the flex_groups struct, it looks
like the accounting was not put into place properly, in some places
manipulating free_inodes rather than used_dirs.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
ext4: Fix possible lost inode write in no journal mode

commit 8b472d739b2ddd8ab7fb278874f696cd95b25a5e upstream (as of v2.6.34-rc6)

In the no-journal case, ext4_write_inode() will fetch the bh and call
sync_dirty_buffer() on it.  However, if the bh has already been
written and the bh reclaimed for some other purpose, AND if the inode
is the only one in the inode table block in use, then
ext4_get_inode_loc() will not read the inode table block from disk,
but as an optimization, fill the block with zero's assuming that its
caller will copy in the on-disk version of the inode.  This is not
done by ext4_write_inode(), so the contents of the inode can simply
get lost.  The fix is to use __ext4_get_inode_loc() with in_mem set to
0, instead of ext4_get_inode_loc().  Long term the API needs to be
fixed so it's obvious why latter is not safe.

Addresses-Google-Bug: #2526446

Signed-off-by: Curt Wohlgemuth <curtw@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>