ext4: Use correct locking for ext4_end_io_nolock()

We must hold i_completed_io_lock when manipulating anything on the
i_completed_io_list linked list.  This includes io->lock, which we
were checking in ext4_end_io_nolock().

So move this check to ext4_end_io_work().  This also has the bonus of
avoiding extra work if it is already done without needing to take the
mutex.

Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit d73d5046a72467d4510825b99e2269e09ad80e15)
ext4: remove unnecessary call to waitqueue_active()

The usage of waitqueue_active() is not necessary, and introduces (I
believe) a hard-to-hit race.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 4e298021216727cc27017c5032ade86167c66256)
ext4: optimize locking for end_io extent conversion

Now that we are doing the locking correctly, we need to grab the
i_completed_io_lock() twice per end_io.  We can clean this up by
removing the structure from the i_complted_io_list, and use this as
the locking mechanism to prevent ext4_flush_completed_IO() racing
against ext4_end_io_work(), instead of clearing the
EXT4_IO_END_UNWRITTEN in io->flag.

In addition, if the ext4_convert_unwritten_extents() returns an error,
we no longer keep the end_io structure on the linked list.  This
doesn't help, because it tends to lock up the file system and wedges
the system.  That's one way to call attention to the problem, but it
doesn't help the overall robustness of the system.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit b82e384c7bb9a19036b4daf58fa216df7cd48aa0)
ext4: Create helper function for EXT4_IO_END_UNWRITTEN and i_aiodio_unwritten

EXT4_IO_END_UNWRITTEN flag set and the increase of i_aiodio_unwritten
should be done simultaneously since ext4_end_io_nolock always clear
the flag and decrease the counter in the same time.

We have found some bugs that the flag is set while leaving
i_aiodio_unwritten unchanged(commit 32c80b32c053d). So this patch just tries
to create a helper function to wrap them to avoid any future bug.
The idea is inspired by Eric.

Cc: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 0edeb71dc9133bfb505d3bf59642e07cd936613e)
ext4: move vars to local scope in ext4_discard_partial_page_buffers_no_lock()

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit e260daf27902b2189a9198f5b64fa4567939bb5b)
ext4: return ENOMEM if find_or_create_pages fails

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 5129d05fda57be13f434dbe8536de39a6c25496d)
ext4: let ext4_discard_partial_buffers handle unaligned range correctly

As comment says, we should handle unaligned range rather than aligned
one.  This fixes a bug found by running xfstests #91.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
(cherry picked from commit edb5ac8993e25143f6af1ab143843a65c52e2a15)
ext4: remove comments about extent mount option in ext4_new_inode()

Remove comments about 'extent' mount option in ext4_new_inode(), since
it's no longer exists.

Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 4af835089984ce9e24c44a51be64c5524788e973)
ext4: Don't normalize an falloc request if it can fit in 1 extent.

If an fallocate request fits in EXT_UNINIT_MAX_LEN, then set the
EXT4_GET_BLOCKS_NO_NORMALIZE flag. For larger fallocate requests,
let mballoc.c normalize the request.

This fixes a problem where large requests were being split into
non-contiguous extents due to commit 556b27abf73: ext4: do not
normalize block requests from fallocate.

Testing:
*) Checked that 8.x MB falloc'ed files are still laid down next to
each other (contiguously).
*) Checked that the maximum size extent (127.9MB) is allocated as 1
extent.
*) Checked that a 1GB file is somewhat contiguous (often 5-6
non-contiguous extents now).
*) Checked that a 120MB file can still be falloc'ed even if there are
no single extents large enough to hold it.

Signed-off-by: Greg Harm <gharm@google.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 3c6fe77017bc6ce489f231c35fed3220b6691836)
ext4: fix a typo in struct ext4_allocation_context

This patch changes "bext" to "best".

Signed-off-by: Robin Dong <sanbai@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit ff3fc1736f1967b59801ab2cf6409fc6c8556b0a)
ext4: warn if direct reclaim tries to writeback pages

Direct reclaim should never writeback pages.  Warn if an attempt is made.

Signed-off-by: Mel Gorman <mgorman@suse.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Johannes Weiner <jweiner@redhat.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Minchan Kim <minchan.kim@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Alex Elder <aelder@sgi.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Chris Mason <chris.mason@oracle.com>
Cc: Dave Hansen <dave@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit 966dbde2c208e07bab7a45a7855e1e693eabe661)
ext4: fix a syntax error in ext4_ext_insert_extent when debugging enabled

This patch fixes a syntax error which omits a comma. Besides this,
logical block number is unsigend 32 bits, so printk should use %u
instead %d.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 32de67569059d22b02dd9323a40220d953642b7e)
ext4: let ext4_ext_rm_leaf work with EXT_DEBUG defined

The variable 'block' is removed by commit 750c9c47, so use the
replacement ex_ee_block instead.

Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit bf52c6f7af55c48ab0fd5f990460b884b428d906)
ext4: ignore journalled data options on remount if fs has no journal

This avoids a confusing failure in the init scripts when the
/etc/fstab has data=writeback or data=journal but the file system does
not have a journal.  So check for this case explicitly, and warn the
user that we are ignoring the (pointless, since they have no journal)
data=* mount option.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit eb513689c97e3e73bb9b4459d490a8e894b4a546)
ext4: Remove kernel_lock annotations

The BKL is gone, these annotations are useless.

Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
(cherry picked from commit 2397256d6218e7bf5147a3b01dcc6aec20fd3916)