As the member fe_len defined in struct ext4_free_extent is expressed as
number of clusters, the variable "size" computation is wrong, we need to
first translate fe_len to block number, then to bytes.
Signed-off-by: NXiaoguang Wang <wangxg.fnst@cn.fujitsu.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>

Commit 27dd4385 ("ext4: introduce reserved space") reserves 2% of
the file system space to make sure metadata allocations will always
succeed.  Given that, tracking the reservation of metadata blocks is
no longer necessary.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

We are spending a lot of time explaining to users what this error
means.  Let's try to improve the message to avoid this problem.
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Cc: stable@vger.kernel.org

We should decrement free clusters counter when block bitmap is marked
as corrupt and free inodes counter when the allocation bitmap is
marked as corrupt to avoid misunderstanding due to incorrect available
size in statfs result.  User can get immediately ENOSPC error from
write begin without reaching for the writepages.

Cc: Darrick J. Wong<darrick.wong@oracle.com>
Reported-by: NAmit Sahrawat <amit.sahrawat83@gmail.com>
Signed-off-by: NNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: NAshish Sangwan <a.sangwan@samsung.com>

aops->write_begin may allocate a new page and make it visible only to have
mark_page_accessed called almost immediately after.  Once the page is
visible the atomic operations are necessary which is noticable overhead
when writing to an in-memory filesystem like tmpfs but should also be
noticable with fast storage.  The objective of the patch is to initialse
the accessed information with non-atomic operations before the page is
visible.

The bulk of filesystems directly or indirectly use
grab_cache_page_write_begin or find_or_create_page for the initial
allocation of a page cache page.  This patch adds an init_page_accessed()
helper which behaves like the first call to mark_page_accessed() but may
called before the page is visible and can be done non-atomically.

The primary APIs of concern in this care are the following and are used
by most filesystems.

	find_get_page
	find_lock_page
	find_or_create_page
	grab_cache_page_nowait
	grab_cache_page_write_begin

All of them are very similar in detail to the patch creates a core helper
pagecache_get_page() which takes a flags parameter that affects its
behavior such as whether the page should be marked accessed or not.  Then
old API is preserved but is basically a thin wrapper around this core
function.

Each of the filesystems are then updated to avoid calling
mark_page_accessed when it is known that the VM interfaces have already
done the job.  There is a slight snag in that the timing of the
mark_page_accessed() has now changed so in rare cases it's possible a page
gets to the end of the LRU as PageReferenced where as previously it might
have been repromoted.  This is expected to be rare but it's worth the
filesystem people thinking about it in case they see a problem with the
timing change.  It is also the case that some filesystems may be marking
pages accessed that previously did not but it makes sense that filesystems
have consistent behaviour in this regard.

The test case used to evaulate this is a simple dd of a large file done
multiple times with the file deleted on each iterations.  The size of the
file is 1/10th physical memory to avoid dirty page balancing.  In the
async case it will be possible that the workload completes without even
hitting the disk and will have variable results but highlight the impact
of mark_page_accessed for async IO.  The sync results are expected to be
more stable.  The exception is tmpfs where the normal case is for the "IO"
to not hit the disk.

The test machine was single socket and UMA to avoid any scheduling or NUMA
artifacts.  Throughput and wall times are presented for sync IO, only wall
times are shown for async as the granularity reported by dd and the
variability is unsuitable for comparison.  As async results were variable
do to writback timings, I'm only reporting the maximum figures.  The sync
results were stable enough to make the mean and stddev uninteresting.

The performance results are reported based on a run with no profiling.
Profile data is based on a separate run with oprofile running.

async dd
                                    3.15.0-rc3            3.15.0-rc3
                                       vanilla           accessed-v2
ext3    Max      elapsed     13.9900 (  0.00%)     11.5900 ( 17.16%)
tmpfs	Max      elapsed      0.5100 (  0.00%)      0.4900 (  3.92%)
btrfs   Max      elapsed     12.8100 (  0.00%)     12.7800 (  0.23%)
ext4	Max      elapsed     18.6000 (  0.00%)     13.3400 ( 28.28%)
xfs	Max      elapsed     12.5600 (  0.00%)      2.0900 ( 83.36%)

The XFS figure is a bit strange as it managed to avoid a worst case by
sheer luck but the average figures looked reasonable.

        samples percentage
ext3       86107    0.9783  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
ext3       23833    0.2710  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext3        5036    0.0573  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
ext4       64566    0.8961  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
ext4        5322    0.0713  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
ext4        2869    0.0384  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs        62126    1.7675  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
xfs         1904    0.0554  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
xfs          103    0.0030  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
btrfs      10655    0.1338  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
btrfs       2020    0.0273  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
btrfs        587    0.0079  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed
tmpfs      59562    3.2628  vmlinux-3.15.0-rc4-vanilla        mark_page_accessed
tmpfs       1210    0.0696  vmlinux-3.15.0-rc4-accessed-v3r25 init_page_accessed
tmpfs         94    0.0054  vmlinux-3.15.0-rc4-accessed-v3r25 mark_page_accessed

[akpm@linux-foundation.org: don't run init_page_accessed() against an uninitialised pointer]
Signed-off-by: NMel Gorman <mgorman@suse.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Tested-by: NPrabhakar Lad <prabhakar.csengg@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The variable "size" is expressed as number of blocks and not as
number of clusters, this could trigger a kernel panic when using
ext4 with the size of a cluster different from the size of a block.

Cc: stable@vger.kernel.org
Signed-off-by: NMaurizio Lombardi <mlombard@redhat.com>
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>

Make them more consistently
Signed-off-by: Nxieliang <xieliang@xiaomi.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Caches from 'ext4_groupinfo_caches' may be in use by other mounts,
which have already existed.  So, it is incorrect to destroy them when
newly requested mount fails.

Found by Linux File System Verification project (linuxtesting.org).
Signed-off-by: NAndrey Tsyvarev <tsyvarev@ispras.ru>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>

This fixes the following sparse warning:

     CHECK   fs/ext4/mballoc.c
   fs/ext4/mballoc.c:5019:9: warning: context imbalance in
   'ext4_trim_extent' - unexpected unlock
Signed-off-by: N"Jon Ernst" <jonernst07@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Return ENOMEM rather than EIO when find_get_page() fails in
ext4_mb_get_buddy_page_lock() and find_or_create_page() fails in
ext4_mb_load_buddy().
Signed-off-by: NYounger Liu <younger.liucn@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

When looking at a bug report with:

> kernel: EXT4-fs: 0 scanned, 0 found

I thought wow, 0 scanned, that's odd?  But it's not odd; it's printing
a variable that is initialized to 0 and never touched again.

It's never been used since the original merge, so I don't really even
know what the original intent was, either.

If anyone knows how to hook it up, speak now via patch, otherwise just
yank it so it's not making a confusing situation more confusing in
kernel logs.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The lowest levels of mballoc set all of the fields of struct
ext4_free_extent except for fe_logical, since they are just trying to
find the requested free set of blocks, and the logical block hasn't
been set yet.  This makes some static code checkers sad.  Set it to
various different debug values, which would be useful when
debugging mballoc if these values were to ever show up due to the
parts of mballoc triyng to use ac->ac_b_ex.fe_logical before it is
properly upper layers of mballoc failing to properly set, usually by
ext4_mb_use_best_found().

Addresses-Coverity-Id: #139697
Addresses-Coverity-Id: #139698
Addresses-Coverity-Id: #139699
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The missing casts can cause the high 64-bits of the physical blocks to
be lost.  Set up new macros which allows us to make sure the right
thing happen, even if at some point we end up supporting larger
logical block numbers.

Thanks to the Emese Revfy and the PaX security team for reporting this
issue.
Reported-by: NPaX Team <pageexec@freemail.hu>
Reported-by: Emese Revfy <re.emese@gmail.com>                                 
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

ext4_mb_put_pa should hold pa->pa_lock before accessing pa->pa_count.
While ext4_mb_use_preallocated checks pa->pa_deleted first and then
increments pa->count later, ext4_mb_put_pa decrements pa->pa_count
before holding pa->pa_lock and then sets pa->pa_deleted.

* Free sequence
ext4_mb_put_pa (1):		atomic_dec_and_test pa->pa_count
ext4_mb_put_pa (2):		lock pa->pa_lock
ext4_mb_put_pa (3):			check pa->pa_deleted
ext4_mb_put_pa (4):			set pa->pa_deleted=1
ext4_mb_put_pa (5):		unlock pa->pa_lock
ext4_mb_put_pa (6):		remove pa from a list
ext4_mb_pa_callback:		free pa

* Use sequence
ext4_mb_use_preallocated (1):	iterate over preallocation
ext4_mb_use_preallocated (2):	lock pa->pa_lock
ext4_mb_use_preallocated (3):		check pa->pa_deleted
ext4_mb_use_preallocated (4):		increase pa->pa_count
ext4_mb_use_preallocated (5):	unlock pa->pa_lock
ext4_mb_release_context:	access pa

* Use-after-free sequence
[initial status]		<pa->pa_deleted = 0, pa_count = 1>
ext4_mb_use_preallocated (1):	iterate over preallocation
ext4_mb_use_preallocated (2):	lock pa->pa_lock
ext4_mb_use_preallocated (3):		check pa->pa_deleted
ext4_mb_put_pa (1):		atomic_dec_and_test pa->pa_count
[pa_count decremented]		<pa->pa_deleted = 0, pa_count = 0>
ext4_mb_use_preallocated (4):		increase pa->pa_count
[pa_count incremented]		<pa->pa_deleted = 0, pa_count = 1>
ext4_mb_use_preallocated (5):	unlock pa->pa_lock
ext4_mb_put_pa (2):		lock pa->pa_lock
ext4_mb_put_pa (3):			check pa->pa_deleted
ext4_mb_put_pa (4):			set pa->pa_deleted=1
[race condition!]		<pa->pa_deleted = 1, pa_count = 1>
ext4_mb_put_pa (5):		unlock pa->pa_lock
ext4_mb_put_pa (6):		remove pa from a list
ext4_mb_pa_callback:		free pa
ext4_mb_release_context:	access pa

AddressSanitizer has detected use-after-free in ext4_mb_new_blocks
Bug report: http://goo.gl/rG1On3Signed-off-by: NJunho Ryu <jayr@google.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

When using FITRIM ioctl on a file system without journal it will
only trim the block group once, no matter how many times you invoke
FITRIM ioctl and how many block you release from the block group.

It is because we only clear EXT4_GROUP_INFO_WAS_TRIMMED_BIT in journal
callback. Fix this by clearing the bit in no journal mode as well.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reported-by: NJorge Fábregas <jorge.fabregas@gmail.com>

When we notice a block-bitmap corruption (because of device failure or
something else), we should mark this group as corrupt and prevent
further block allocations/deallocations from it. Currently, we end up
generating one error message for every block in the bitmap. This
potentially could make the system unstable as noticed in some
bugs. With this patch, the error will be printed only the first time
and mark the entire block group as corrupted. This prevents future
access allocations/deallocations from it.

Also tested by corrupting the block
bitmap and forcefully introducing the mb_free_blocks error:
(1) create a largefile (2Gb)
$ dd if=/dev/zero of=largefile oflag=direct bs=10485760 count=200
(2) umount filesystem. use dumpe2fs to see which block-bitmaps
are in use by largefile and note their block numbers
(3) use dd to zero-out the used block bitmaps
$ dd if=/dev/zero of=/dev/hdc4 bs=4096 seek=14 count=8 oflag=direct
(4) mount the FS and delete the largefile.
(5) recreate the largefile. verify that the new largefile does not
get any blocks from the groups marked as bad.
Without the patch, we will see mb_free_blocks error for each bit in
each zero'ed out bitmap at (4). With the patch, we only see the error
once per blockgroup:
[  309.706803] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 15: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[  309.720824] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 14: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[  309.732858] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[  309.748321] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 13: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[  309.760331] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[  309.769695] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 12: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[  309.781721] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[  309.798166] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 11: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[  309.810184] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[  309.819532] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 10: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.

Google-Bug-Id: 7258357

[darrick.wong@oracle.com]
Further modifications (by Darrick) to make more obvious that this corruption
bit applies to blocks only.  Set the corruption flag if the block group bitmap
verification fails.

Original-author: Aditya Kali <adityakali@google.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

reaim workfile.dbase test easily triggers warning in
ext4_da_update_reserve_space():

EXT4-fs warning (device ram0): ext4_da_update_reserve_space:365:
ino 12, allocated 1 with only 0 reserved metadata blocks (releasing 1
blocks with reserved 9 data blocks)

The problem is that (one of) tests creates file and then randomly writes
to it with O_SYNC. That results in writing back pages of the file in
random order so we create extents for written blocks say 0, 2, 4, 6, 8
- this last allocation also allocates new block for extents. Then we
writeout block 1 so we have extents 0-2, 4, 6, 8 and we release
indirect extent block because extents fit in the inode again. Then we
writeout block 10 and we need to allocate indirect extent block again
which triggers the warning because we don't have the reservation
anymore.

Fix the problem by giving back freed metadata blocks resulting from
extent merging into inode's reservation pool.
Signed-off-by: NJan Kara <jack@suse.cz>

The filesystem should not be marked inconsistent if ext4_free_blocks()
is not able to allocate memory.  Unfortunately some callers (most
notably ext4_truncate) don't have a way to reflect an error back up to
the VFS.  And even if we did, most userspace applications won't deal
with most system calls returning ENOMEM anyway.
Reported-by: NNagachandra P <nagachandra@gmail.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

If memory allocation in ext4_mb_new_group_pa() is failed,
it returns error code, ext4_mb_new_preallocation() propages it,
but ext4_mb_new_blocks() ignores it.

An observed result was:

- allocation fail means ext4_mb_new_group_pa() does not update
  ext4_allocation_context;

- ext4_mb_new_blocks() sets ext4_allocation_request->len (ar->len =
  ac->ac_b_ex.fe_len;) to number of blocks preallocated (512) instead
  of number of blocks requested (1);

- that activates update cycle in ext4_splice_branch():
    for (i = 1; i < blks; i++) <-- blks is 512 instead of 1 here
      *(where->p + i) = cpu_to_le32(current_block++);

- it iterates 511 times and corrupts a chunk of memory including inode
  structure;

- page fault happens at EXT4_SB(inode->i_sb) in ext4_mark_inode_dirty();

- system hangs with 'scheduling while atomic' BUG.

The patch implements a check for ext4_mb_new_preallocation() error
code and handles its failure as if ext4_mb_regular_allocator() fails.

Found by Linux File System Verification project (linuxtesting.org).

[ Patch restructed by tytso to make the flow of control easier to follow. ]
Signed-off-by: NAlexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

For a file systems with a very large number of block groups, if all of
the block group bitmaps are in memory and the file system is
relatively badly fragmented, it's possible ext4_mb_regular_allocator()
to take a long time trying to find a good match.  This is especially
true if the tuning parameter mb_max_to_scan has been sent to a very
large number.  So add a cond_resched() to avoid soft lockup warnings
and to provide better system responsiveness.

For ext4_free_blocks(), if we are deleting a large range of blocks,
and data=journal is enabled so that EXT4_FREE_BLOCKS_FORGET is passed,
the loop to call sb_find_get_block() and to call ext4_forget() can
take over 10-15 milliseocnds or more.  So it's better to add a
cond_resched() here a well.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

In the case where we are allocating for a non-extent file,
we must limit the groups we allocate from to those below
2^32 blocks, and ext4_mb_regular_allocator() attempts to
do this initially by putting a cap on ngroups for the
subsequent search loop.

However, the initial target group comes in from the 
allocation context (ac), and it may already be beyond
the artificially limited ngroups.  In this case,
the limit

	if (group == ngroups)
		group = 0;

at the top of the loop is never true, and the loop will
run away.

Catch this case inside the loop and reset the search to
start at group 0.

[sandeen@redhat.com: add commit msg & comments]
Signed-off-by: NLachlan McIlroy <lmcilroy@redhat.com>
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

This patch should fix sparse complains about shadow declatations.
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The only part of proc_dir_entry the code outside of fs/proc
really cares about is PDE(inode)->data.  Provide a helper
for that; static inline for now, eventually will be moved
to fs/proc, along with the knowledge of struct proc_dir_entry
layout.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Improve mb_free_blocks speed by clearing entire range at once instead
of iterating over each bit. Freeing block-by-block also makes buddy
bitmap subtree flip twice making most of the work a no-op. Very few
bits in buddy bitmap require change, e.g. freeing entire group is a 1
bit flip only.  As a result, releasing blocks of 60G file now takes
5ms instead of 2.7s.  This is especially good for non-preemptive
kernels as there is no rescheduling during release.
Signed-off-by: NAndrey Sidorov <qrxd43@motorola.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Currently on many places in ext4 we're using
ext4_get_group_no_and_offset() even though we're only interested in
knowing the block group of the particular block, not the offset within
the block group so we can use more efficient way to compute block
group.

This patch introduces ext4_get_group_number() which computes block
group for a given block much more efficiently. Use this function
instead of ext4_get_group_no_and_offset() everywhere where we're only
interested in knowing the block group.
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

It is incorrect to use list_for_each_entry_safe() for journal callback
traversial because ->next may be removed by other task:
->ext4_mb_free_metadata()
  ->ext4_mb_free_metadata()
    ->ext4_journal_callback_del()

This results in the following issue:

WARNING: at lib/list_debug.c:62 __list_del_entry+0x1c0/0x250()
Hardware name:
list_del corruption. prev->next should be ffff88019a4ec198, but was 6b6b6b6b6b6b6b6b
Modules linked in: cpufreq_ondemand acpi_cpufreq freq_table mperf coretemp kvm_intel kvm crc32c_intel ghash_clmulni_intel microcode sg xhci_hcd button sd_mod crc_t10dif aesni_intel ablk_helper cryptd lrw aes_x86_64 xts gf128mul ahci libahci pata_acpi ata_generic dm_mirror dm_region_hash dm_log dm_mod
Pid: 16400, comm: jbd2/dm-1-8 Tainted: G        W    3.8.0-rc3+ #107
Call Trace:
 [<ffffffff8106fb0d>] warn_slowpath_common+0xad/0xf0
 [<ffffffff8106fc06>] warn_slowpath_fmt+0x46/0x50
 [<ffffffff813637e9>] ? ext4_journal_commit_callback+0x99/0xc0
 [<ffffffff8148cae0>] __list_del_entry+0x1c0/0x250
 [<ffffffff813637bf>] ext4_journal_commit_callback+0x6f/0xc0
 [<ffffffff813ca336>] jbd2_journal_commit_transaction+0x23a6/0x2570
 [<ffffffff8108aa42>] ? try_to_del_timer_sync+0x82/0xa0
 [<ffffffff8108b491>] ? del_timer_sync+0x91/0x1e0
 [<ffffffff813d3ecf>] kjournald2+0x19f/0x6a0
 [<ffffffff810ad630>] ? wake_up_bit+0x40/0x40
 [<ffffffff813d3d30>] ? bit_spin_lock+0x80/0x80
 [<ffffffff810ac6be>] kthread+0x10e/0x120
 [<ffffffff810ac5b0>] ? __init_kthread_worker+0x70/0x70
 [<ffffffff818ff6ac>] ret_from_fork+0x7c/0xb0
 [<ffffffff810ac5b0>] ? __init_kthread_worker+0x70/0x70

This patch fix the issue as follows:
- ext4_journal_commit_callback() make list truly traversial safe
  simply by always starting from list_head
- fix race between two ext4_journal_callback_del() and
  ext4_journal_callback_try_del()
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NJan Kara <jack@suse.cz>
Cc: stable@vger.kernel.com

Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>

A user who was using a 8TB+ file system and with a very large flexbg
size (> 65536) could cause the atomic_t used in the struct flex_groups
to overflow.  This was detected by PaX security patchset:

http://forums.grsecurity.net/viewtopic.php?f=3&t=3289&p=12551#p12551

This bug was introduced in commit 9f24e420, so it's been around
since 2.6.30.  :-(

Fix this by using an atomic64_t for struct orlav_stats's
free_clusters.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>
Cc: stable@vger.kernel.org

Using yield() is strongly discouraged (see sched/core.c) especially
since we can just use cond_resched().

Replace all use of yield() with cond_resched().
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Remove unused variable 'freed' in ext4_free_blocks().
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

We're using macro EXT4_B2C() to convert number of blocks to number of
clusters for bigalloc file systems.  However, we should be using
EXT4_NUM_B2C().
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

There are multiple reasons to move away from debugfs.  First of all,
we are only using it for a single parameter, and it is much more
complicated to set up (some 30 lines of code compared to 3), and one
more thing that might fail while loading the ext4 module.

Secondly, as a module paramter it can be specified as a boot option if
ext4 is built into the kernel, or as a parameter when the module is
loaded, and it can also be manipulated dynamically under
/sys/module/ext4/parameters/mballoc_debug.  So it is more flexible.

Ultimately we want to move away from using mb_debug() towards
tracepoints, but for now this is still a useful simplification of the
code base.
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

The ext4 block allocator only maintains buddy bitmaps for chunks which
are less than or equal to one quarter of a block group.  That is, for
a file aystem with a 1k blocksize, and where the number of blocks in a
block group is 8192 blocks, the largest chunk size tracked by buddy
bitmaps is 2048 blocks.

For a file system with a 4k blocksize, and where the number of blocks
in a block group is 32768 blocks, the largest chunk size tracked by
buddy bitmaps is 8192 blocks.

To work around this code, mballoc.c before this commit would truncate
allocation requests to the number of blocks in a block group minus 10.
Why 10?  Aside from being a completely arbitrary number, it avoids
block allocation to be a power of two larger than 25% of the block
group.  If you try to explicitly fallocate 50% of the block group
size, this will demonstrate the problem; the block allocation code
will scan the all of the blocks in the file system with cr==0 (since
the request is for a natural power of two), but then completely fail
for all blocks groups, since the buddy bitmaps don't track chunk sizes
of 50% of the block group.

To fix this, in these we use ext4_mb_complex_scan_group() instead of
ext4_mb_simple_scan_group().
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger@dilger.ca>

In ext4_mb_add_n_trim(), lg_prealloc_lock should be taken when
changing the lg_prealloc_list.
Signed-off-by: NNiu Yawei <yawei.niu@intel.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

We should warn user then the discard request fails. However we need to
exclude -EOPNOTSUPP case since parts of the device might not support it
while other parts can. So print the kernel warning when the error !=
-EOPNOTSUPP is returned from ext4_issue_discard().

We should also handle error cases in batched discard, again excluding
EOPNOTSUPP.
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

I think the whole function could be made prettier, but
that goto really took the cake for too-clever-by-half.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

Currently if len argument in ext4_trim_fs() is smaller than one block,
the 'end' variable underflow. Avoid that by returning EINVAL if len is
smaller than file system block.

Also remove useless unlikely().
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

In mke2fs, we only checksum the whole bitmap block and it is right.
While in the kernel, we use EXT4_BLOCKS_PER_GROUP to indicate the
size of the checksumed bitmap which is wrong when we enable bigalloc.
The right size should be EXT4_CLUSTERS_PER_GROUP and this patch fixes
it.

Also as every caller of ext4_block_bitmap_csum_set and
ext4_block_bitmap_csum_verify pass in EXT4_BLOCKS_PER_GROUP(sb)/8,
we'd better removes this parameter and sets it in the function itself.
Signed-off-by: NTao Ma <boyu.mt@taobao.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: NLukas Czerner <lczerner@redhat.com>
Cc: stable@vger.kernel.org

With a minor tweaks regarding minimum extent size to discard and
discarded bytes reporting the FITRIM can be enabled on bigalloc file
system and it works without any problem.

This patch fixes minlen handling and discarded bytes reporting to
take into consideration bigalloc enabled file systems and finally
removes the restriction and allow FITRIM to be used on file system with
bigalloc feature enabled.
Reviewed-by: NCarlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: NLukas Czerner <lczerner@redhat.com>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>