Pull ext4 updates from Ted Ts'o:
 "Lots of bugs fixes, including Zheng and Jan's extent status shrinker
  fixes, which should improve CPU utilization and potential soft lockups
  under heavy memory pressure, and Eric Whitney's bigalloc fixes"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (26 commits)
  ext4: ext4_da_convert_inline_data_to_extent drop locked page after error
  ext4: fix suboptimal seek_{data,hole} extents traversial
  ext4: ext4_inline_data_fiemap should respect callers argument
  ext4: prevent fsreentrance deadlock for inline_data
  ext4: forbid journal_async_commit in data=ordered mode
  jbd2: remove unnecessary NULL check before iput()
  ext4: Remove an unnecessary check for NULL before iput()
  ext4: remove unneeded code in ext4_unlink
  ext4: don't count external journal blocks as overhead
  ext4: remove never taken branch from ext4_ext_shift_path_extents()
  ext4: create nojournal_checksum mount option
  ext4: update comments regarding ext4_delete_inode()
  ext4: cleanup GFP flags inside resize path
  ext4: introduce aging to extent status tree
  ext4: cleanup flag definitions for extent status tree
  ext4: limit number of scanned extents in status tree shrinker
  ext4: move handling of list of shrinkable inodes into extent status code
  ext4: change LRU to round-robin in extent status tree shrinker
  ext4: cache extent hole in extent status tree for ext4_da_map_blocks()
  ext4: fix block reservation for bigalloc filesystems
  ...

When we're enabling journal features, we cannot use the predicate
jbd2_journal_has_csum_v2or3() because we haven't yet set the sb
feature flag fields!  Moreover, we just finished loading the shash
driver, so the test is unnecessary; calculate the seed always.

Without this patch, we fail to initialize the checksum seed the first
time we turn on journal_checksum, which means that all journal blocks
written during that first mount are corrupt.  Transactions written
after the second mount will be fine, since the feature flag will be
set in the journal superblock.  xfstests generic/{034,321,322} are the
regression tests.

(This is important for 3.18.)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.coM>
Reported-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Clear all three journal checksum feature flags before turning on
whichever journal checksum options we want.  Rearrange the error
checking so that newer flags get complained about first.

Reported-by: TR Reardon <thomas_reardon@hotmail.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

Sicne the jbd/jbd2 superblock is not released until the file system is
unmounted, allocate the buffer cache from the non-moveable area to
allow page migration and CMA allocations to more easily succeed.

Signed-off-by: Gioh Kim <gioh.kim@lge.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

It turns out that there are some serious problems with the on-disk
format of journal checksum v2.  The foremost is that the function to
calculate descriptor tag size returns sizes that are too big.  This
causes alignment issues on some architectures and is compounded by the
fact that some parts of jbd2 use the structure size (incorrectly) to
determine the presence of a 64bit journal instead of checking the
feature flags.

Therefore, introduce journal checksum v3, which enlarges the
descriptor block tag format to allow for full 32-bit checksums of
journal blocks, fix the journal tag function to return the correct
sizes, and fix the jbd2 recovery code to use feature flags to
determine 64bitness.

Add a few function helpers so we don't have to open-code quite so
many pieces.

Switching to a 16-byte block size was found to increase journal size
overhead by a maximum of 0.1%, to convert a 32-bit journal with no
checksumming to a 32-bit journal with checksum v3 enabled.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reported-by: TR Reardon <thomas_reardon@hotmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

The j_state_lock is one of the hottest locks in the jbd2 layer and
thus one of its scalability bottlenecks.

We don't need to be holding the j_state_lock while we are calling
wake_up(&journal->j_wait_commit), so release the lock a little bit
earlier.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Mark functions as static in jbd2/journal.c because they are not used
outside this file.

This eliminates the following warning in jbd2/journal.c:
fs/jbd2/journal.c:125:5: warning: no previous prototype for ‘jbd2_verify_csum_type’ [-Wmissing-prototypes]
fs/jbd2/journal.c:146:5: warning: no previous prototype for ‘jbd2_superblock_csum_verify’ [-Wmissing-prototypes]
fs/jbd2/journal.c:154:6: warning: no previous prototype for ‘jbd2_superblock_csum_set’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

Rename performed via: perl -pi -e 's/JBD:/JBD2:/g' fs/jbd2/*.c

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

Some of KERN_EMERG printk messages do not really deserve this log
level and the one in log_wait_commit() is even rather useless (the
journal has been previously aborted and *that* is where we should have
been complaining). So make some messages just KERN_ERR and remove the
useless message.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>