commit 853a0c25baf96b028de1654bea1e0c8857eadf3d upstream.

When we hit EIO while writing LVID, the buffer uptodate bit is cleared.
This then results in an anoying warning from mark_buffer_dirty() when we
write the buffer again. So just set uptodate flag unconditionally.

Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-udf-2.6:
  UDF: Close small mem leak in udf_find_entry()
  udf: Fix directory corruption after extent merging
  udf: Protect udf_file_aio_write from possible races
  udf: Remove unnecessary bkl usages
  udf: Use of s_alloc_mutex to serialize udf_relocate_blocks() execution
  udf: Replace bkl with the UDF_I(inode)->i_data_sem for protect udf_inode_info struct
  udf: Remove BKL from free space counting functions
  udf: Call udf_add_free_space() for more blocks at once in udf_free_blocks()
  udf: Remove BKL from udf_put_super() and udf_remount_fs()
  udf: Protect default inode credentials by rwlock
  udf: Protect all modifications of LVID with s_alloc_mutex
  udf: Move handling of uniqueID into a helper function and protect it by a s_alloc_mutex
  udf: Remove BKL from udf_update_inode
  udf: Convert UDF_SB(sb)->s_flags to use bitops
  fs/udf: Add printf format/argument verification
  fs/udf: Use vzalloc

(Evil merge: this also removes the BKL dependency from the Kconfig file)

RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

The udf_readdir(), udf_lookup(), udf_create(), udf_mknod(), udf_mkdir(),
udf_rmdir(), udf_link(), udf_get_parent() and udf_unlink() seems already
adequately protected by i_mutex held by VFS invoking calls. The udf_rename()
instead should be already protected by lock_rename again by VFS. The
udf_ioctl(), udf_fill_super() and udf_evict_inode() don't requires any further
protection.

This work was supported by a hardware donation from the CE Linux Forum.

Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
Signed-off-by: Jan Kara <jack@suse.cz>

Replace bkl with the UDF_I(inode)->i_data_sem rw semaphore in
udf_release_file(), udf_symlink(), udf_symlink_filler(), udf_get_block(),
udf_block_map(), and udf_setattr(). The rule now is that any operation
on regular file's or symlink's extents (or generally allocation information
including goal block) needs to hold i_data_sem.

This work was supported by a hardware donation from the CE Linux Forum.

Signed-off-by: Alessio Igor Bogani <abogani@texware.it>
Signed-off-by: Jan Kara <jack@suse.cz>

udf_count_free_bitmap() does not need BKL because bitmaps are in a fixed
place on disk and so we can count set bits without serialization.
udf_count_free_table() is now protected by s_alloc_mutex instead of BKL
to get a consistent view of free space extents.

Signed-off-by: Jan Kara <jack@suse.cz>

udf_put_super() does not need BKL because the filesystem is shut down so
there's nothing to race with. The credential changes in udf_remount_fs()
and LVID changes are now protected by dedicated locks so we can remove BKL
from this function as well.

Signed-off-by: Jan Kara <jack@suse.cz>

Superblock carries credentials (uid, gid, etc.) which are used as default
values in __udf_read_inode() when media does not provide these. These
credentials can change during remount so we protect them by a rwlock so that
each inode gets a consistent set of credentials.

Signed-off-by: Jan Kara <jack@suse.cz>

udf_open_lvid() and udf_close_lvid() were modifying LVID without
s_alloc_mutex. Since they can be called from remount, the modification
could race with other filesystem modifications of LVID so protect them
by s_alloc_mutex just to be sure.

Signed-off-by: Jan Kara <jack@suse.cz>

uniqueID handling has been duplicated in three places. Move it into a common
helper. Since we modify an LVID buffer with uniqueID update, we take
sbi->s_alloc_mutex to protect agaist other modifications of the structure.

Signed-off-by: Jan Kara <jack@suse.cz>