The iput() function was called in up to three cases by the udf_fill_super()
function during error handling even if the passed data structure element
contained still a null pointer. This implementation detail could be improved
by the introduction of another jump label.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Jan Kara <jack@suse.cz>

The iput() function tests whether its argument is NULL and then
returns immediately. Thus the test around the call is not needed.

This issue was detected by using the Coccinelle software.

Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Jan Kara <jack@suse.cz>

Some UDF media have special inodes (like VAT or metadata partition
inodes) whose link_count is 0. Thus commit 4071b9136223 (udf: Properly
detect stale inodes) broke loading these inodes because udf_iget()
started returning -ESTALE for them. Since we still need to properly
detect stale inodes queried by NFS, create two variants of udf_iget() -
one which is used for looking up special inodes (which ignores
link_count == 0) and one which is used for other cases which return
ESTALE when link_count == 0.

Fixes: 4071b913622316970d0e1919f7d82b4403fec5f2
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>

sys_tz is already declared in include/linux/time.h

Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Jan Kara <jack@suse.cz>

Currently write(2) updating i_size and close(2) of the file can race in
such a way that udf_truncate_tail_extent() called from
udf_file_release() sees old i_size but already new extents added by the
running write call. This results in complaints like:
  UDF-fs: warning (device vdb2): udf_truncate_tail_extent: Too long extent
    after EOF in inode 877: i_size: 0 lbcount: 1073739776 extent 0+1073739776
  UDF-fs: error (device vdb2): udf_truncate_tail_extent: Extent after EOF
    in inode 877

Fix the problem by grabbing i_mutex in udf_file_release() to be sure
i_size is consistent with current state of extent list. Also avoid
truncating tail extent unnecessarily when the file is still open for
writing.

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

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jan Kara <jack@suse.cz>

Currently udf_iget() (triggered by NFS) can race with udf_new_inode()
leading to two inode structures with the same inode number:

nfsd: iget_locked() creates inode
nfsd: try to read from disk, block on that.
udf_new_inode(): allocate inode with that inumber
udf_new_inode(): insert it into icache, set it up and dirty
udf_write_inode(): write inode into buffer cache
nfsd: get CPU again, look into buffer cache, see nice and sane on-disk
  inode, set the in-core inode from it

Fix the problem by putting inode into icache in locked state (I_NEW set)
and unlocking it only after it's fully set up.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jan Kara <jack@suse.cz>

boilerplate code in udf_{create,mknod,symlink} taken to new helper

symlink case converted to unique id calculated by udf_new_inode() - no
point finding a new one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jan Kara <jack@suse.cz>

Currently UDF doesn't initialize i_generation in any way and thus NFS
can easily get reallocated inodes from stale file handles. Luckily UDF
already has a unique object identifier associated with each inode -
i_unique. Use that for initialization of i_generation.

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

NFS can easily ask for inodes that are already deleted. Currently UDF
happily returns such inodes which is a bug. Return -ESTALE if
udf_read_inode() is asked to read deleted inode.

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