Since allocating an object from a mempool never fails when
__GFP_DIRECT_RECLAIM (which is included in GFP_NOFS) is set, the check
for failure to allocate a bio_post_read_ctx is unnecessary.  Remove it.
Signed-off-by: NEric Biggers <ebiggers@google.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Youling reported in mailing list:

https://www.linuxquestions.org/questions/linux-newbie-8/the-file-system-f2fs-is-broken-4175666043/

https://www.linux.org/threads/the-file-system-f2fs-is-broken.26490/

There is a test case can corrupt f2fs image:
- dd if=/dev/zero of=/swapfile bs=1M count=4096
- chmod 600 /swapfile
- mkswap /swapfile
- swapon --discard /swapfile

The root cause is f2fs_swap_activate() intends to return zero value
to setup_swap_extents() to enable SWP_FS mode (swap file goes through
fs), in this flow, setup_swap_extents() setups swap extent with wrong
block address range, result in discard_swap() erasing incorrect address.

Because f2fs_swap_activate() has pinned swapfile, its data block
address will not change, it's safe to let swap to handle IO through
raw device, so we can get rid of SWAP_FS mode and initial swap extents
inside f2fs_swap_activate(), by this way, later discard_swap() can trim
in right address range.

Fixes: 4969c06a ("f2fs: support swap file w/ DIO")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch tries to support compression in f2fs.

- New term named cluster is defined as basic unit of compression, file can
be divided into multiple clusters logically. One cluster includes 4 << n
(n >= 0) logical pages, compression size is also cluster size, each of
cluster can be compressed or not.

- In cluster metadata layout, one special flag is used to indicate cluster
is compressed one or normal one, for compressed cluster, following metadata
maps cluster to [1, 4 << n - 1] physical blocks, in where f2fs stores
data including compress header and compressed data.

- In order to eliminate write amplification during overwrite, F2FS only
support compression on write-once file, data can be compressed only when
all logical blocks in file are valid and cluster compress ratio is lower
than specified threshold.

- To enable compression on regular inode, there are three ways:
* chattr +c file
* chattr +c dir; touch dir/file
* mount w/ -o compress_extension=ext; touch file.ext

Compress metadata layout:
                             [Dnode Structure]
             +-----------------------------------------------+
             | cluster 1 | cluster 2 | ......... | cluster N |
             +-----------------------------------------------+
             .           .                       .           .
       .                       .                .                      .
  .         Compressed Cluster       .        .        Normal Cluster            .
+----------+---------+---------+---------+  +---------+---------+---------+---------+
|compr flag| block 1 | block 2 | block 3 |  | block 1 | block 2 | block 3 | block 4 |
+----------+---------+---------+---------+  +---------+---------+---------+---------+
           .                             .
         .                                           .
       .                                                           .
      +-------------+-------------+----------+----------------------------+
      | data length | data chksum | reserved |      compressed data       |
      +-------------+-------------+----------+----------------------------+

Changelog:

20190326:
- fix error handling of read_end_io().
- remove unneeded comments in f2fs_encrypt_one_page().

20190327:
- fix wrong use of f2fs_cluster_is_full() in f2fs_mpage_readpages().
- don't jump into loop directly to avoid uninitialized variables.
- add TODO tag in error path of f2fs_write_cache_pages().

20190328:
- fix wrong merge condition in f2fs_read_multi_pages().
- check compressed file in f2fs_post_read_required().

20190401
- allow overwrite on non-compressed cluster.
- check cluster meta before writing compressed data.

20190402
- don't preallocate blocks for compressed file.

- add lz4 compress algorithm
- process multiple post read works in one workqueue
  Now f2fs supports processing post read work in multiple workqueue,
  it shows low performance due to schedule overhead of multiple
  workqueue executing orderly.

20190921
- compress: support buffered overwrite
C: compress cluster flag
V: valid block address
N: NEW_ADDR

One cluster contain 4 blocks

 before overwrite   after overwrite

- VVVV		->	CVNN
- CVNN		->	VVVV

- CVNN		->	CVNN
- CVNN		->	CVVV

- CVVV		->	CVNN
- CVVV		->	CVVV

20191029
- add kconfig F2FS_FS_COMPRESSION to isolate compression related
codes, add kconfig F2FS_FS_{LZO,LZ4} to cover backend algorithm.
note that: will remove lzo backend if Jaegeuk agreed that too.
- update codes according to Eric's comments.

20191101
- apply fixes from Jaegeuk

20191113
- apply fixes from Jaegeuk
- split workqueue for fsverity

20191216
- apply fixes from Jaegeuk

20200117
- fix to avoid NULL pointer dereference

[Jaegeuk Kim]
- add tracepoint for f2fs_{,de}compress_pages()
- fix many bugs and add some compression stats
- fix overwrite/mmap bugs
- address 32bit build error, reported by Geert.
- bug fixes when handling errors and i_compressed_blocks

Reported-by: <noreply@ellerman.id.au>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In low memory scenario, we can allocate multiple bios without
submitting any of them.

- f2fs_write_checkpoint()
 - block_operations()
  - f2fs_sync_node_pages()
   step 1) flush cold nodes, allocate new bio from mempool
   - bio_alloc()
    - mempool_alloc()
   step 2) flush hot nodes, allocate a bio from mempool
   - bio_alloc()
    - mempool_alloc()
   step 3) flush warm nodes, be stuck in below call path
   - bio_alloc()
    - mempool_alloc()
     - loop to wait mempool element release, as we only
       reserved memory for two bio allocation, however above
       allocated two bios may never be submitted.

So we need avoid using default bioset, in this patch we introduce a
private bioset, in where we enlarg mempool element count to total
number of log header, so that we can make sure we have enough
backuped memory pool in scenario of allocating/holding multiple
bios.
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch avoids some unnecessary locks for quota files when write_begin
fails.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The previous preallocation and DIO decision like below.

                         allow_outplace_dio              !allow_outplace_dio
f2fs_force_buffered_io   (*) No_Prealloc / Buffered_IO   Prealloc / Buffered_IO
!f2fs_force_buffered_io  No_Prealloc / DIO               Prealloc / DIO

But, Javier reported Case (*) where zoned device bypassed preallocation but
fell back to buffered writes in f2fs_direct_IO(), resulting in stale data
being read.

In order to fix the issue, actually we need to preallocate blocks whenever
we fall back to buffered IO like this. No change is made in the other cases.

                         allow_outplace_dio              !allow_outplace_dio
f2fs_force_buffered_io   (*) Prealloc / Buffered_IO      Prealloc / Buffered_IO
!f2fs_force_buffered_io  No_Prealloc / DIO               Prealloc / DIO
Reported-and-tested-by: NJavier Gonzalez <javier@javigon.com>
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Tested-by: NShin'ichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Reviewed-by: NJavier González <javier@javigon.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Eric mentioned, bare printk{,_ratelimited} won't show which
filesystem instance these message is coming from, this patch tries
to show fs instance with sb->s_id field in all places we missed
before.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We expect 64-bit calculation result from below statement, however
in 32-bit machine, looped left shift operation on pgoff_t type
variable may cause overflow issue, fix it by forcing type cast.

page->index << PAGE_SHIFT;

Fixes: 26de9b11 ("f2fs: avoid unnecessary updating inode during fsync")
Fixes: 0a2aa8fb ("f2fs: refactor __exchange_data_block for speed up")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In commit 8648de2c ("f2fs: add bio cache for IPU"), we added
f2fs_submit_ipu_bio() in __write_data_page() as below:

__write_data_page()

	if (!S_ISDIR(inode->i_mode) && !IS_NOQUOTA(inode)) {
		f2fs_submit_ipu_bio(sbi, bio, page);
		....
	}

in order to avoid below deadlock:

Thread A				Thread B
- __write_data_page (inode x, page y)
 - f2fs_do_write_data_page
  - set_page_writeback        ---- set writeback flag in page y
  - f2fs_inplace_write_data
 - f2fs_balance_fs
					 - lock gc_mutex
 - lock gc_mutex
					  - f2fs_gc
					   - do_garbage_collect
					    - gc_data_segment
					     - move_data_page
					      - f2fs_wait_on_page_writeback
					       - wait_on_page_writeback  --- wait writeback of page y

However, the bio submission breaks the merge of IPU IOs.

So in this patch let's add a global bio cache for merged IPU pages,
then f2fs_wait_on_page_writeback() is able to submit bio if a
writebacked page is cached in global bio cache.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In f2fs_allocate_data_block(), we will reset fio.retry for IO
alignment feature instead of IO serialization feature.

In addition, spread F2FS_IO_ALIGNED() to check IO alignment
feature status explicitly.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In f2fs_map_blocks(), we should bail out once __allocate_data_block()
failed.

Fixes: f847c699 ("f2fs: allow out-place-update for direct IO in LFS mode")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In LFS mode, por_fsstress testcase reports a bug as below:

[ASSERT] (fsck_chk_inode_blk: 931)  --> ino: 0x12fe has wrong ext: [pgofs:142, blk:215424, len:16]

Since commit f847c699 ("f2fs: allow out-place-update for direct
IO in LFS mode"), we start to allow OPU mode for direct IO, however,
we missed to update extent cache in __allocate_data_block(), finally,
it cause extent field being inconsistent with physical block address,
fix it.

Fixes: f847c699 ("f2fs: allow out-place-update for direct IO in LFS mode")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch changes sematics of f2fs_is_checkpoint_ready()'s return
value as: return true when checkpoint is ready, other return false,
it can improve readability of below conditions.

f2fs_submit_page_write()
...
	if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
				!f2fs_is_checkpoint_ready(sbi))
		__submit_merged_bio(io);

f2fs_balance_fs()
...
	if (!f2fs_is_checkpoint_ready(sbi))
		return;
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Just cleanup, no logic change.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Adjust f2fs_fiemap() to support fiemap() on directory inode.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Since 07173c3e ("block: enable multipage bvecs"), one bio vector
can store multi pages, so that we can not calculate max IO size of
bio as PAGE_SIZE * bio->bi_max_vecs. However IO alignment feature of
f2fs always has that assumption, so finally, it may cause panic during
IO submission as below stack.

 kernel BUG at fs/f2fs/data.c:317!
 RIP: 0010:__submit_merged_bio+0x8b0/0x8c0
 Call Trace:
  f2fs_submit_page_write+0x3cd/0xdd0
  do_write_page+0x15d/0x360
  f2fs_outplace_write_data+0xd7/0x210
  f2fs_do_write_data_page+0x43b/0xf30
  __write_data_page+0xcf6/0x1140
  f2fs_write_cache_pages+0x3ba/0xb40
  f2fs_write_data_pages+0x3dd/0x8b0
  do_writepages+0xbb/0x1e0
  __writeback_single_inode+0xb6/0x800
  writeback_sb_inodes+0x441/0x910
  wb_writeback+0x261/0x650
  wb_workfn+0x1f9/0x7a0
  process_one_work+0x503/0x970
  worker_thread+0x7d/0x820
  kthread+0x1ad/0x210
  ret_from_fork+0x35/0x40

This patch adds one extra condition to check left space in bio while
trying merging page to bio, to avoid panic.

This bug was reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=204043Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Wrap merge condition into function for readability, no logic change.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch fixes livelock in the below call path when writing swap pages.

[46374.617256] c2    701  __switch_to+0xe4/0x100
[46374.617265] c2    701  __schedule+0x80c/0xbc4
[46374.617273] c2    701  schedule+0x74/0x98
[46374.617281] c2    701  rwsem_down_read_failed+0x190/0x234
[46374.617291] c2    701  down_read+0x58/0x5c
[46374.617300] c2    701  f2fs_map_blocks+0x138/0x9a8
[46374.617310] c2    701  get_data_block_dio_write+0x74/0x104
[46374.617320] c2    701  __blockdev_direct_IO+0x1350/0x3930
[46374.617331] c2    701  f2fs_direct_IO+0x55c/0x8bc
[46374.617341] c2    701  __swap_writepage+0x1d0/0x3e8
[46374.617351] c2    701  swap_writepage+0x44/0x54
[46374.617360] c2    701  shrink_page_list+0x140/0xe80
[46374.617371] c2    701  shrink_inactive_list+0x510/0x918
[46374.617381] c2    701  shrink_node_memcg+0x2d4/0x804
[46374.617391] c2    701  shrink_node+0x10c/0x2f8
[46374.617400] c2    701  do_try_to_free_pages+0x178/0x38c
[46374.617410] c2    701  try_to_free_pages+0x348/0x4b8
[46374.617419] c2    701  __alloc_pages_nodemask+0x7f8/0x1014
[46374.617429] c2    701  pagecache_get_page+0x184/0x2cc
[46374.617438] c2    701  f2fs_new_node_page+0x60/0x41c
[46374.617449] c2    701  f2fs_new_inode_page+0x50/0x7c
[46374.617460] c2    701  f2fs_init_inode_metadata+0x128/0x530
[46374.617472] c2    701  f2fs_add_inline_entry+0x138/0xd64
[46374.617480] c2    701  f2fs_do_add_link+0xf4/0x178
[46374.617488] c2    701  f2fs_create+0x1e4/0x3ac
[46374.617497] c2    701  path_openat+0xdc0/0x1308
[46374.617507] c2    701  do_filp_open+0x78/0x124
[46374.617516] c2    701  do_sys_open+0x134/0x248
[46374.617525] c2    701  SyS_openat+0x14/0x20
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Add fs-verity support to f2fs.  fs-verity is a filesystem feature that
enables transparent integrity protection and authentication of read-only
files.  It uses a dm-verity like mechanism at the file level: a Merkle
tree is used to verify any block in the file in log(filesize) time.  It
is implemented mainly by helper functions in fs/verity/.  See
Documentation/filesystems/fsverity.rst for the full documentation.

The f2fs support for fs-verity consists of:

- Adding a filesystem feature flag and an inode flag for fs-verity.

- Implementing the fsverity_operations to support enabling verity on an
  inode and reading/writing the verity metadata.

- Updating ->readpages() to verify data as it's read from verity files
  and to support reading verity metadata pages.

- Updating ->write_begin(), ->write_end(), and ->writepages() to support
  writing verity metadata pages.

- Calling the fs-verity hooks for ->open(), ->setattr(), and ->ioctl().

Like ext4, f2fs stores the verity metadata (Merkle tree and
fsverity_descriptor) past the end of the file, starting at the first 64K
boundary beyond i_size.  This approach works because (a) verity files
are readonly, and (b) pages fully beyond i_size aren't visible to
userspace but can be read/written internally by f2fs with only some
relatively small changes to f2fs.  Extended attributes cannot be used
because (a) f2fs limits the total size of an inode's xattr entries to
4096 bytes, which wouldn't be enough for even a single Merkle tree
block, and (b) f2fs encryption doesn't encrypt xattrs, yet the verity
metadata *must* be encrypted when the file is because it contains hashes
of the plaintext data.
Acked-by: NJaegeuk Kim <jaegeuk@kernel.org>
Acked-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>

migrate_page_move_mapping() doesn't use the mode argument.  Remove it
and update callers accordingly.

Link: http://lkml.kernel.org/r/20190508210301.8472-1-keith.busch@intel.comSigned-off-by: NKeith Busch <keith.busch@intel.com>
Reviewed-by: NZi Yan <ziy@nvidia.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

wbc_account_io() does a very specific job - try to see which cgroup is
actually dirtying an inode and transfer its ownership to the majority
dirtier if needed.  The name is too generic and confusing.  Let's
rename it to something more specific.
Reviewed-by: NJan Kara <jack@suse.cz>
Signed-off-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs uses EFAULT as error number to indicate filesystem is corrupted
all the time, but generic filesystems use EUCLEAN for such condition,
we need to change to follow others.

This patch adds two new macros as below to wrap more generic error
code macros, and spread them in code.

EFSBADCRC	EBADMSG		/* Bad CRC detected */
EFSCORRUPTED	EUCLEAN		/* Filesystem is corrupted */
Reported-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Acked-by: NPavel Machek <pavel@ucw.cz>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Rename fscrypt_encrypt_page() to fscrypt_encrypt_pagecache_blocks() and
redefine its behavior to encrypt all filesystem blocks from the given
region of the given page, rather than assuming that the region consists
of just one filesystem block.  Also remove the 'inode' and 'lblk_num'
parameters, since they can be retrieved from the page as it's already
assumed to be a pagecache page.

This is in preparation for allowing encryption on ext4 filesystems with
blocksize != PAGE_SIZE.

This is based on work by Chandan Rajendra.
Reviewed-by: NChandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>

Currently, bounce page handling for writes to encrypted files is
unnecessarily complicated.  A fscrypt_ctx is allocated along with each
bounce page, page_private(bounce_page) points to this fscrypt_ctx, and
fscrypt_ctx::w::control_page points to the original pagecache page.

However, because writes don't use the fscrypt_ctx for anything else,
there's no reason why page_private(bounce_page) can't just point to the
original pagecache page directly.

Therefore, this patch makes this change.  In the process, it also cleans
up the API exposed to filesystems that allows testing whether a page is
a bounce page, getting the pagecache page from a bounce page, and
freeing a bounce page.
Reviewed-by: NChandan Rajendra <chandan@linux.ibm.com>
Signed-off-by: NEric Biggers <ebiggers@google.com>

As Hagbard Celine reported:

[  615.697824] INFO: task kworker/u16:5:344 blocked for more than 120 seconds.
[  615.697825]       Not tainted 5.0.15-gentoo-f2fslog #4
[  615.697826] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs"
disables this message.
[  615.697827] kworker/u16:5   D    0   344      2 0x80000000
[  615.697831] Workqueue: writeback wb_workfn (flush-259:0)
[  615.697832] Call Trace:
[  615.697836]  ? __schedule+0x2c5/0x8b0
[  615.697839]  schedule+0x32/0x80
[  615.697841]  schedule_preempt_disabled+0x14/0x20
[  615.697842]  __mutex_lock.isra.8+0x2ba/0x4d0
[  615.697845]  ? log_store+0xf5/0x260
[  615.697848]  f2fs_write_data_pages+0x133/0x320
[  615.697851]  ? trace_hardirqs_on+0x2c/0xe0
[  615.697854]  do_writepages+0x41/0xd0
[  615.697857]  __filemap_fdatawrite_range+0x81/0xb0
[  615.697859]  f2fs_sync_dirty_inodes+0x1dd/0x200
[  615.697861]  f2fs_balance_fs_bg+0x2a7/0x2c0
[  615.697863]  ? up_read+0x5/0x20
[  615.697865]  ? f2fs_do_write_data_page+0x2cb/0x940
[  615.697867]  f2fs_balance_fs+0xe5/0x2c0
[  615.697869]  __write_data_page+0x1c8/0x6e0
[  615.697873]  f2fs_write_cache_pages+0x1e0/0x450
[  615.697878]  f2fs_write_data_pages+0x14b/0x320
[  615.697880]  ? trace_hardirqs_on+0x2c/0xe0
[  615.697883]  do_writepages+0x41/0xd0
[  615.697885]  __filemap_fdatawrite_range+0x81/0xb0
[  615.697887]  f2fs_sync_dirty_inodes+0x1dd/0x200
[  615.697889]  f2fs_balance_fs_bg+0x2a7/0x2c0
[  615.697891]  f2fs_write_node_pages+0x51/0x220
[  615.697894]  do_writepages+0x41/0xd0
[  615.697897]  __writeback_single_inode+0x3d/0x3d0
[  615.697899]  writeback_sb_inodes+0x1e8/0x410
[  615.697902]  __writeback_inodes_wb+0x5d/0xb0
[  615.697904]  wb_writeback+0x28f/0x340
[  615.697906]  ? cpumask_next+0x16/0x20
[  615.697908]  wb_workfn+0x33e/0x420
[  615.697911]  process_one_work+0x1a1/0x3d0
[  615.697913]  worker_thread+0x30/0x380
[  615.697915]  ? process_one_work+0x3d0/0x3d0
[  615.697916]  kthread+0x116/0x130
[  615.697918]  ? kthread_create_worker_on_cpu+0x70/0x70
[  615.697921]  ret_from_fork+0x3a/0x50

There is still deadloop in below condition:

d A
- do_writepages
 - f2fs_write_node_pages
  - f2fs_balance_fs_bg
   - f2fs_sync_dirty_inodes
    - f2fs_write_cache_pages
     - mutex_lock(&sbi->writepages)	-- lock once
     - __write_data_page
      - f2fs_balance_fs_bg
       - f2fs_sync_dirty_inodes
        - f2fs_write_data_pages
         - mutex_lock(&sbi->writepages)	-- lock again

Thread A			Thread B
- do_writepages
 - f2fs_write_node_pages
  - f2fs_balance_fs_bg
   - f2fs_sync_dirty_inodes
    - .cp_task = current
				- f2fs_sync_dirty_inodes
				 - .cp_task = current
				 - filemap_fdatawrite
				 - .cp_task = NULL
    - filemap_fdatawrite
     - f2fs_write_cache_pages
      - enter f2fs_balance_fs_bg since .cp_task is NULL
    - .cp_task = NULL

Change as below to avoid this:
- add condition to avoid holding .writepages mutex lock in path
of data flush
- introduce mutex lock sbi.flush_lock to exclude concurrent data
flush in background.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

SQLite in Wal mode may trigger sequential IPU write in db-wal file, after
commit d1b3e72d ("f2fs: submit bio of in-place-update pages"), we
lost the chance of merging page in inner managed bio cache, result in
submitting more small-sized IO.

So let's add temporary bio in writepages() to cache mergeable write IO as
much as possible.

Test case:
1. xfs_io -f /mnt/f2fs/file -c "pwrite 0 65536" -c "fsync"
2. xfs_io -f /mnt/f2fs/file -c "pwrite 0 65536" -c "fsync"

Before:
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65544, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65552, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65560, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65568, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65576, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65584, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65592, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65600, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65608, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65616, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65624, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65632, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65640, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65648, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65656, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65664, size = 4096
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), NODE, sector = 57352, size = 4096

After:
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), DATA, sector = 65544, size = 65536
f2fs_submit_write_bio: dev = (251,0)/(251,0), rw = WRITE(S), NODE, sector = 57368, size = 4096
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Previously, f2fs_is_valid_blkaddr(, blkaddr, DATA_GENERIC) will check
whether @blkaddr locates in main area or not.

That check is weak, since the block address in range of main area can
point to the address which is not valid in segment info table, and we
can not detect such condition, we may suffer worse corruption as system
continues running.

So this patch introduce DATA_GENERIC_ENHANCE to enhance the sanity check
which trigger SIT bitmap check rather than only range check.

This patch did below changes as wel:
- set SBI_NEED_FSCK in f2fs_is_valid_blkaddr().
- get rid of is_valid_data_blkaddr() to avoid panic if blkaddr is invalid.
- introduce verify_fio_blkaddr() to wrap fio {new,old}_blkaddr validation check.
- spread blkaddr check in:
 * f2fs_get_node_info()
 * __read_out_blkaddrs()
 * f2fs_submit_page_read()
 * ra_data_block()
 * do_recover_data()

This patch can fix bug reported from bugzilla below:

https://bugzilla.kernel.org/show_bug.cgi?id=203215
https://bugzilla.kernel.org/show_bug.cgi?id=203223
https://bugzilla.kernel.org/show_bug.cgi?id=203231
https://bugzilla.kernel.org/show_bug.cgi?id=203235
https://bugzilla.kernel.org/show_bug.cgi?id=203241

= Update by Jaegeuk Kim =

DATA_GENERIC_ENHANCE enhanced to validate block addresses on read/write paths.
But, xfstest/generic/446 compalins some generated kernel messages saying invalid
bitmap was detected when reading a block. The reaons is, when we get the
block addresses from extent_cache, there is no lock to synchronize it from
truncating the blocks in parallel.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces f2fs_read_single_page() to wrap core operations
of reading one page in f2fs_mpage_readpages().

In addition, if we failed in f2fs_mpage_readpages(), propagate error
number to f2fs_read_data_page(), for f2fs_read_data_pages() path,
always return success.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch fixes to set FI_UPDATE_WRITE only if in-place IO was issued.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch changes codes as below:
- don't use is_read_io() as a condition to judge the meta IO.
- use .is_por to replace .is_meta to indicate IO is from recovery explicitly.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

We only have two callers that need the integer loop iterator, and they
can easily maintain it themselves.
Suggested-by: NMatthew Wilcox <willy@infradead.org>
Reviewed-by: NJohannes Thumshirn <jthumshirn@suse.de>
Acked-by: NDavid Sterba <dsterba@suse.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Acked-by: NColy Li <colyli@suse.de>
Reviewed-by: NMatthew Wilcox <willy@infradead.org>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJens Axboe <axboe@kernel.dk>

changed passing function argument "0 to NULL" to fix below sparse
warning

fs/f2fs/data.c:426:47: warning: Using plain integer as NULL pointer
Signed-off-by: NHariprasad Kelam <hariprasad.kelam@gmail.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Reviewed-by: NMukesh Ojha <mojha@codeaurora.org>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Hagbard Celine reported:

Hi, this is a long standing bug that I've hit before on older kernels,
but I was not able to get the syslog saved because of the nature of
the bug. This time I had booted form a pen-drive, and was able to save
the log to it's efi-partition.
What i did to trigger it was to create a partition and format it f2fs,
then mount it with options:
"rw,relatime,lazytime,background_gc=on,disable_ext_identify,discard,heap,user_xattr,inline_xattr,acl,inline_data,inline_dentry,flush_merge,data_flush,extent_cache,mode=adaptive,active_logs=6,whint_mode=fs-based,alloc_mode=default,fsync_mode=strict".
Then I unpacked a big .tar.xz to the partition (I used a
gentoo-stage3-tarball as I was in process of installing Gentoo).

Same options just without data_flush gives no problems.

Mar 20 20:54:01 usbgentoo kernel: FAT-fs (nvme0n1p4): Volume was not
properly unmounted. Some data may be corrupt. Please run fsck.
Mar 20 21:05:23 usbgentoo kernel: kworker/dying (1588) used greatest
stack depth: 12064 bytes left
Mar 20 21:06:40 usbgentoo kernel: BUG: stack guard page was hit at
00000000a4b0733c (stack is 0000000056016422..0000000096e7463f)
Mar 20 21:06:40 usbgentoo kernel: kernel stack overflow

......

Mar 20 21:06:40 usbgentoo kernel: Call Trace:
Mar 20 21:06:40 usbgentoo kernel:  read_node_page+0x71/0xf0
Mar 20 21:06:40 usbgentoo kernel:  ? xas_load+0x8/0x50
Mar 20 21:06:40 usbgentoo kernel:  __get_node_page+0x73/0x2a0
Mar 20 21:06:40 usbgentoo kernel:  f2fs_get_dnode_of_data+0x34e/0x580
Mar 20 21:06:40 usbgentoo kernel:  f2fs_write_inline_data+0x5e/0x2a0
Mar 20 21:06:40 usbgentoo kernel:  __write_data_page+0x421/0x690
Mar 20 21:06:40 usbgentoo kernel:  f2fs_write_cache_pages+0x1cf/0x460
Mar 20 21:06:40 usbgentoo kernel:  f2fs_write_data_pages+0x2b3/0x2e0
Mar 20 21:06:40 usbgentoo kernel:  ? f2fs_inode_chksum_verify+0x1d/0xc0
Mar 20 21:06:40 usbgentoo kernel:  ? read_node_page+0x71/0xf0
Mar 20 21:06:40 usbgentoo kernel:  do_writepages+0x3c/0xd0
Mar 20 21:06:40 usbgentoo kernel:  __filemap_fdatawrite_range+0x7c/0xb0
Mar 20 21:06:40 usbgentoo kernel:  f2fs_sync_dirty_inodes+0xf2/0x200
Mar 20 21:06:40 usbgentoo kernel:  f2fs_balance_fs_bg+0x2a3/0x2c0
Mar 20 21:06:40 usbgentoo kernel:  ? f2fs_inode_dirtied+0x21/0xc0
Mar 20 21:06:40 usbgentoo kernel:  f2fs_balance_fs+0xd6/0x2b0
Mar 20 21:06:40 usbgentoo kernel:  __write_data_page+0x4fb/0x690

......

Mar 20 21:06:40 usbgentoo kernel:  __writeback_single_inode+0x2a1/0x340
Mar 20 21:06:40 usbgentoo kernel:  ? soft_cursor+0x1b4/0x220
Mar 20 21:06:40 usbgentoo kernel:  writeback_sb_inodes+0x1d5/0x3e0
Mar 20 21:06:40 usbgentoo kernel:  __writeback_inodes_wb+0x58/0xa0
Mar 20 21:06:40 usbgentoo kernel:  wb_writeback+0x250/0x2e0
Mar 20 21:06:40 usbgentoo kernel:  ? 0xffffffff8c000000
Mar 20 21:06:40 usbgentoo kernel:  ? cpumask_next+0x16/0x20
Mar 20 21:06:40 usbgentoo kernel:  wb_workfn+0x2f6/0x3b0
Mar 20 21:06:40 usbgentoo kernel:  ? __switch_to_asm+0x40/0x70
Mar 20 21:06:40 usbgentoo kernel:  process_one_work+0x1f5/0x3f0
Mar 20 21:06:40 usbgentoo kernel:  worker_thread+0x28/0x3c0
Mar 20 21:06:40 usbgentoo kernel:  ? rescuer_thread+0x330/0x330
Mar 20 21:06:40 usbgentoo kernel:  kthread+0x10e/0x130
Mar 20 21:06:40 usbgentoo kernel:  ? kthread_create_on_node+0x60/0x60
Mar 20 21:06:40 usbgentoo kernel:  ret_from_fork+0x35/0x40

The root cause is that we run into an infinite recursive calling in
between f2fs_balance_fs_bg and writepage() as described below:

- f2fs_write_data_pages		--- A
 - __write_data_page
  - f2fs_balance_fs
   - f2fs_balance_fs_bg		--- B
    - f2fs_sync_dirty_inodes
     - filemap_fdatawrite
      - f2fs_write_data_pages	--- A
...
          - f2fs_balance_fs_bg	--- B
...

In order to fix this issue, let's detect such condition in __write_data_page()
and just skip calling f2fs_balance_fs() recursively.
Reported-by: NHagbard Celine <hagbardcelin@gmail.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

For a single device mount using a zoned block device, the zone
information for the device is stored in the sbi->devs single entry
array and sbi->s_ndevs is set to 1. This differs from a single device
mount using a regular block device which does not allocate sbi->devs
and sets sbi->s_ndevs to 0.

However, sbi->s_devs == 0 condition is used throughout the code to
differentiate a single device mount from a multi-device mount where
sbi->s_ndevs is always larger than 1. This results in problems with
single zoned block device volumes as these are treated as multi-device
mounts but do not have the start_blk and end_blk information set. One
of the problem observed is skipping of zone discard issuing resulting in
write commands being issued to full zones or unaligned to a zone write
pointer.

Fix this problem by simply treating the cases sbi->s_ndevs == 0 (single
regular block device mount) and sbi->s_ndevs == 1 (single zoned block
device mount) in the same manner. This is done by introducing the
helper function f2fs_is_multi_device() and using this helper in place
of direct tests of sbi->s_ndevs value, improving code readability.

Fixes: 7bb3a371 ("f2fs: Fix zoned block device support")
Cc: <stable@vger.kernel.org>
Signed-off-by: NDamien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In f2fs_mpage_readpages(), if page is beyond EOF, we should just
zero out it, but previously, before checking previous mapping
info, we missed to check filesize boundary, fix it.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Gao Xiang reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=202749

f2fs may skip pageout() due to incorrect page reference count.

The problem here is that MM defined the rule [1] very clearly that
once page was set with PG_private flag, we should increment the
refcount in that page, also main flows like pageout(), migrate_page()
will assume there is one additional page reference count if
page_has_private() returns true.

But currently, f2fs won't add/del refcount when changing PG_private
flag. Anyway, f2fs should follow MM's rule to make MM's related flows
running as expected.

[1] https://lore.kernel.org/lkml/2b19b3c4-2bc4-15fa-15cc-27a13e5c7af1@aol.com/Reported-by: NGao Xiang <gaoxiang25@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Since 8c242db9 ("f2fs: fix stale ATOMIC_WRITTEN_PAGE private pointer"),
we've started to not skip clear private flag for atomic_write page
truncation, so removing old wrong comment in f2fs_invalidate_page().
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

For IPU path of f2fs_do_write_data_page(), in its error path, we
need to release encrypted page and fscrypt context, otherwise it
will cause memory leak.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Note that __GFP_ZERO is not supported for mempool_alloc,
which also documented in the mempool_alloc comments.
Signed-off-by: NGao Xiang <gaoxiang25@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>