(256 << sizeof(x)) - 1 is not the maximal possible value of x...
In reality, the maximal allowed value for UDF FileLinkCount is
65535.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

* '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>

Hi,

There's a small memory leak in fs/udf/namei.c::udf_find_entry().

We dynamically allocate memory for 'fname' with kmalloc() and in most
situations we free it before we leave the function, but there is one
situation where we do not (but should). This patch closes the leak by
jumping to the 'out_ok' label which does the correct cleanup rather than
doing half the cleanup and returning directly.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jan Kara <jack@suse.cz>

If udf_bread() called from udf_add_entry() managed to merge created extent to
an already existing one (or if previous extents could be merged), the code
truncating the last extent to proper size would just overwrite the freshly
allocated extent with an extent that used to be in that place.  This obviously
results in a directory corruption. Fix the problem by properly reloading the
last extent.

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

Code doing conversion from INICB file to a normal file in udf_file_aio_write()
is not protected by any lock from other code modifying the inode. Use
i_alloc_sem for that.

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

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>

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>