f2fs: ro: compress: fix to avoid caching unaligned extent

Mapping info from dump.f2fs:
i_addr[0x2d] cluster flag [0xfffffffe : 4294967294]
i_addr[0x2e] [0x 10428 : 66600]
i_addr[0x2f] [0x 10429 : 66601]
i_addr[0x30] [0x 1042a : 66602]

f2fs_io fiemap 37 1 /mnt/f2fs/disk-58390c8c.raw

Previsouly, it missed to align fofs and ofs_in_node to cluster_size,
result in adding incorrect read extent cache, fix it.

Before:
f2fs_update_read_extent_tree_range: dev = (253,48), ino = 5, pgofs = 37, len = 4, blkaddr = 66600, c_len = 3

After:
f2fs_update_read_extent_tree_range: dev = (253,48), ino = 5, pgofs = 36, len = 4, blkaddr = 66600, c_len = 3

Fixes: 94afd6d6e525 ("f2fs: extent cache: support unaligned extent")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: remove some redundant codes in f2fs_cache_compressed_page

Just remove some redundant codes, no logic change.

Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support printk_ratelimited() in f2fs_printk()

This patch supports using printk_ratelimited() in f2fs_printk(), and
wrap ratelimited f2fs_printk() into f2fs_{err,warn,info}_ratelimited(),
then, use these new helps to clean up codes.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix to cover normal cluster write with cp_rwsem

When we overwrite compressed cluster w/ normal cluster, we should
not unlock cp_rwsem during f2fs_write_raw_pages(), otherwise data
will be corrupted if partial blocks were persisted before CP & SPOR,
due to cluster metadata wasn't updated atomically.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Reviewed-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix to guarantee persisting compressed blocks by CP

If data block in compressed cluster is not persisted with metadata
during checkpoint, after SPOR, the data may be corrupted, let's
guarantee to write compressed page by checkpoint.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Reviewed-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to tag gcing flag on page during block migration

It needs to add missing gcing flag on page during block migration,
in order to garantee migrated data be persisted during checkpoint,
otherwise out-of-order persistency between data and node may cause
data corruption after SPOR.

Similar issue was fixed by commit 2d1fe8a86bf5 ("f2fs: fix to tag
gcing flag on page during file defragment").

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: delete obsolete FI_FIRST_BLOCK_WRITTEN

Commit 3c6c2bebef79 ("f2fs: avoid punch_hole overhead when releasing
volatile data") introduced FI_FIRST_BLOCK_WRITTEN as below reason:

This patch is to avoid some punch_hole overhead when releasing volatile
data. If volatile data was not written yet, we just can make the first
page as zero.

After commit 7bc155fec5b3 ("f2fs: kill volatile write support"), we
won't support volatile write, but it missed to remove obsolete
FI_FIRST_BLOCK_WRITTEN, delete it in this patch.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fs: convert error_remove_page to error_remove_folio

There were already assertions that we were not passing a tail page to
error_remove_page(), so make the compiler enforce that by converting
everything to pass and use a folio.

Link: https://lkml.kernel.org/r/20231117161447.2461643-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

f2fs: avoid format-overflow warning

With gcc and W=1 option, there's a warning like this:

fs/f2fs/compress.c: In function ‘f2fs_init_page_array_cache’:
fs/f2fs/compress.c:1984:47: error: ‘%u’ directive writing between
1 and 7 bytes into a region of size between 5 and 8
[-Werror=format-overflow=]
1984 | sprintf(slab_name, "f2fs_page_array_entry-%u:%u", MAJOR(dev),
MINOR(dev));
| ^~

String "f2fs_page_array_entry-%u:%u" can up to 35. The first "%u" can up
to 4 and the second "%u" can up to 7, so total size is "24 + 4 + 7 = 35".
slab_name's size should be 35 rather than 32.

Cc: stable@vger.kernel.org
Signed-off-by: Su Hui <suhui@nfschina.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: do sanity check on cluster when CONFIG_F2FS_CHECK_FS is on

This patch covers sanity check logic on cluster w/ CONFIG_F2FS_CHECK_FS,
otherwise, there will be performance regression while querying cluster
mapping info.

Callers of f2fs_is_compressed_cluster() only care about whether cluster
is compressed or not, rather than # of valid blocks in compressed cluster,
so, let's adjust f2fs_is_compressed_cluster()'s logic according to
caller's requirement.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: don't handle error case of f2fs_compress_alloc_page()

f2fs_compress_alloc_page() uses mempool to allocate memory, it never
fail, don't handle error case in its callers.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

filemap: Add fgf_t typedef

Similarly to gfp_t, define fgf_t as its own type to prevent various
misuses and confusion. Leave the flags as FGP_* for now to reduce the
size of this patch; they will be converted to FGF_* later. Move the
documentation to the definition of the type insted of burying it in the
__filemap_get_folio() documentation.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>

f2fs: add helper to check compression level

This patch adds a helper function to check if compression level is
valid.

Signed-off-by: Sheng Yong <shengyong@oppo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: assign default compression level

Let's avoid any confusion from assigning compress_level=0 for LZ4HC and ZSTD.

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

f2fs: flush error flags in workqueue

In IRQ context, it wakes up workqueue to record errors into on-disk
superblock fields rather than in-memory fields.

Fixes: 1aa161e43106 ("f2fs: fix scheduling while atomic in decompression path")
Fixes: 95fa90c9e5a7 ("f2fs: support recording errors into superblock")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix potential deadlock due to unpaired node_write lock use

If S_NOQUOTA is cleared from inode during data page writeback of quota
file, it may miss to unlock node_write lock, result in potential
deadlock, fix to use the lock in paired.

Kworker Thread
- writepage
if (IS_NOQUOTA())
f2fs_down_read(&sbi->node_write);
- vfs_cleanup_quota_inode
- inode->i_flags &= ~S_NOQUOTA;
if (IS_NOQUOTA())
f2fs_up_read(&sbi->node_write);

Fixes: 79963d967b49 ("f2fs: shrink node_write lock coverage")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix the wrong condition to determine atomic context

Should use !in_task for irq context.

Cc: stable@vger.kernel.org
Fixes: 1aa161e43106 ("f2fs: fix scheduling while atomic in decompression path")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: merge lz4hc_compress_pages() to lz4_compress_pages()

Remove unnecessary lz4hc_compress_pages().

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
[Jaegeuk Kim: clean up]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix scheduling while atomic in decompression path

[ 16.945668][ C0] Call trace:
[ 16.945678][ C0] dump_backtrace+0x110/0x204
[ 16.945706][ C0] dump_stack_lvl+0x84/0xbc
[ 16.945735][ C0] __schedule_bug+0xb8/0x1ac
[ 16.945756][ C0] __schedule+0x724/0xbdc
[ 16.945778][ C0] schedule+0x154/0x258
[ 16.945793][ C0] bit_wait_io+0x48/0xa4
[ 16.945808][ C0] out_of_line_wait_on_bit+0x114/0x198
[ 16.945824][ C0] __sync_dirty_buffer+0x1f8/0x2e8
[ 16.945853][ C0] __f2fs_commit_super+0x140/0x1f4
[ 16.945881][ C0] f2fs_commit_super+0x110/0x28c
[ 16.945898][ C0] f2fs_handle_error+0x1f4/0x2f4
[ 16.945917][ C0] f2fs_decompress_cluster+0xc4/0x450
[ 16.945942][ C0] f2fs_end_read_compressed_page+0xc0/0xfc
[ 16.945959][ C0] f2fs_handle_step_decompress+0x118/0x1cc
[ 16.945978][ C0] f2fs_read_end_io+0x168/0x2b0
[ 16.945993][ C0] bio_endio+0x25c/0x2c8
[ 16.946015][ C0] dm_io_dec_pending+0x3e8/0x57c
[ 16.946052][ C0] clone_endio+0x134/0x254
[ 16.946069][ C0] bio_endio+0x25c/0x2c8
[ 16.946084][ C0] blk_update_request+0x1d4/0x478
[ 16.946103][ C0] scsi_end_request+0x38/0x4cc
[ 16.946129][ C0] scsi_io_completion+0x94/0x184
[ 16.946147][ C0] scsi_finish_command+0xe8/0x154
[ 16.946164][ C0] scsi_complete+0x90/0x1d8
[ 16.946181][ C0] blk_done_softirq+0xa4/0x11c
[ 16.946198][ C0] _stext+0x184/0x614
[ 16.946214][ C0] __irq_exit_rcu+0x78/0x144
[ 16.946234][ C0] handle_domain_irq+0xd4/0x154
[ 16.946260][ C0] gic_handle_irq.33881+0x5c/0x27c
[ 16.946281][ C0] call_on_irq_stack+0x40/0x70
[ 16.946298][ C0] do_interrupt_handler+0x48/0xa4
[ 16.946313][ C0] el1_interrupt+0x38/0x68
[ 16.946346][ C0] el1h_64_irq_handler+0x20/0x30
[ 16.946362][ C0] el1h_64_irq+0x78/0x7c
[ 16.946377][ C0] finish_task_switch+0xc8/0x3d8
[ 16.946394][ C0] __schedule+0x600/0xbdc
[ 16.946408][ C0] preempt_schedule_common+0x34/0x5c
[ 16.946423][ C0] preempt_schedule+0x44/0x48
[ 16.946438][ C0] process_one_work+0x30c/0x550
[ 16.946456][ C0] worker_thread+0x414/0x8bc
[ 16.946472][ C0] kthread+0x16c/0x1e0
[ 16.946486][ C0] ret_from_fork+0x10/0x20

Fixes: bff139b49d9f ("f2fs: handle decompress only post processing in softirq")
Fixes: 95fa90c9e5a7 ("f2fs: support recording errors into superblock")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix to call f2fs_wait_on_page_writeback() in f2fs_write_raw_pages()

BUG_ON() will be triggered when writing files concurrently,
because the same page is writtenback multiple times.

1597 void folio_end_writeback(struct folio *folio)
1598 {
......
1618 if (!__folio_end_writeback(folio))
1619 BUG();
......
1625 }

kernel BUG at mm/filemap.c:1619!
Call Trace:
<TASK>
f2fs_write_end_io+0x1a0/0x370
blk_update_request+0x6c/0x410
blk_mq_end_request+0x15/0x130
blk_complete_reqs+0x3c/0x50
__do_softirq+0xb8/0x29b
? sort_range+0x20/0x20
run_ksoftirqd+0x19/0x20
smpboot_thread_fn+0x10b/0x1d0
kthread+0xde/0x110
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x22/0x30
</TASK>

Below is the concurrency scenario:

[Process A] [Process B] [Process C]
f2fs_write_raw_pages()
- redirty_page_for_writepage()
- unlock page()
f2fs_do_write_data_page()
- lock_page()
- clear_page_dirty_for_io()
- set_page_writeback() [1st writeback]
.....
- unlock page()

generic_perform_write()
- f2fs_write_begin()
- wait_for_stable_page()

- f2fs_write_end()
- set_page_dirty()

- lock_page()
- f2fs_do_write_data_page()
- set_page_writeback() [2st writeback]

This problem was introduced by the previous commit 7377e853967b ("f2fs:
compress: fix potential deadlock of compress file"). All pagelocks were
released in f2fs_write_raw_pages(), but whether the page was
in the writeback state was ignored in the subsequent writing process.
Let's fix it by waiting for the page to writeback before writing.

Cc: Christoph Hellwig <hch@lst.de>
Fixes: 4c8ff7095bef ("f2fs: support data compression")
Fixes: 7377e853967b ("f2fs: compress: fix potential deadlock of compress file")
Signed-off-by: Qi Han <hanqi@vivo.com>
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: convert to use bitmap API

Let's use BIT() and GENMASK() instead of open it.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix typos in comments

This patch is to fix typos in f2fs files.

Signed-off-by: Jinyoung Choi <j-young.choi@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up i_compress_flag and i_compress_level usage

.i_compress_level was introduced by commit 3fde13f817e2 ("f2fs: compress:
support compress level"), but never be used.

This patch updates as below:
- load high 8-bits of on-disk .i_compress_flag to in-memory .i_compress_level
- load low 8-bits of on-disk .i_compress_flag to in-memory .i_compress_flag
- change type of in-memory .i_compress_flag from unsigned short to unsigned
char.

w/ above changes, we can avoid unneeded bit shift whenever during
.init_compress_ctx(), and shrink size of struct f2fs_inode_info.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: reduce stack memory cost by using bitfield in struct f2fs_io_info

This patch tries to use bitfield in struct f2fs_io_info to improve
memory usage.

struct f2fs_io_info {
...
unsigned int need_lock:8; /* indicate we need to lock cp_rwsem */
unsigned int version:8; /* version of the node */
unsigned int submitted:1; /* indicate IO submission */
unsigned int in_list:1; /* indicate fio is in io_list */
unsigned int is_por:1; /* indicate IO is from recovery or not */
unsigned int retry:1; /* need to reallocate block address */
unsigned int encrypted:1; /* indicate file is encrypted */
unsigned int post_read:1; /* require post read */
...
};

After this patch, size of struct f2fs_io_info reduces from 136 to 120.

[Nathan: fix a compile warning (single-bit-bitfield-constant-conversion)]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: mark f2fs_init_compress_mempool w/ __init

f2fs_init_compress_mempool() only initializes the memory pool during
the f2fs module init phase. Let's mark it as __init like any other
function.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: start freeing cluster pages from the unused number

We can start freeing cluster page(s) from which compression
is not used. It will get better performance.

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: split __submit_bio

Split __submit_bio into one function each for reads and writes, and a
helper for aligning writes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to support .migrate_folio for compressed inode

Add missed .migrate_folio for compressed inode, in order to support
migration of compressed inode's page.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do some cleanup for f2fs module init

Just for cleanup, no functional changes.

Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: set zstd compress level correctly

Fixes: cf30f6a5f0c6 ("lib: zstd: Add kernel-specific API")
Signed-off-by: Sheng Yong <shengyong@oppo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Reviewed-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

fsverity: stop using PG_error to track error status

As a step towards freeing the PG_error flag for other uses, change ext4
and f2fs to stop using PG_error to track verity errors. Instead, if a
verity error occurs, just mark the whole bio as failed. The coarser
granularity isn't really a problem since it isn't any worse than what
the block layer provides, and errors from a multi-page readahead aren't
reported to applications unless a single-page read fails too.

f2fs supports compression, which makes the f2fs changes a bit more
complicated than desired, but the basic premise still works.

Note: there are still a few uses of PageError in f2fs, but they are on
the write path, so they are unrelated and this patch doesn't touch them.

Reviewed-by: Chao Yu <chao@kernel.org>
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20221129070401.156114-1-ebiggers@kernel.org

f2fs: support recording errors into superblock

This patch supports to record detail reason of FSCORRUPTED error into
f2fs_super_block.s_errors[].

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove redundant check in f2fs_sanity_check_cluster

It have checked "compressed" at the entry of
f2fs_sanity_check_cluster, just remove the
redundant check for better performance here.

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use COMPRESS_MAPPING to get compress cache mapping

Just use the defined COMPRESS_MAPPING to get compress cache
mapping instaed of direct accessing name.

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: simplify code in f2fs_prepare_decomp_mem

It could return directly after init_decompress_ctx.

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: use onstack pages instead of pvec

Since pvec have 15 pages, it not a multiple of 4, when write compressed
pages, write in 64K as a unit, it will call pagevec_lookup_range_tag
agagin, sometimes this will take a lot of time.
Use onstack pages instead of pvec to mitigate this problem.

Signed-off-by: Fengnan Chang <fengnanchang@gmail.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: intorduce f2fs_all_cluster_page_ready

When write total cluster, all pages is uptodate, there is not need to call
f2fs_prepare_compress_overwrite, intorduce f2fs_all_cluster_page_ready
to avoid this.

Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: handle decompress only post processing in softirq

Now decompression is being handled in workqueue and it makes read I/O
latency non-deterministic, because of the non-deterministic scheduling
nature of workqueues. So, I made it handled in softirq context only if
possible, not in low memory devices, since this modification will
maintain decompresion related memory a little longer.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: initialize page_array_entry slab only if compression feature is on

Otherwise, in image which doesn't support compression feature,
page_array_entry will be initialized w/o use.

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Convert f2fs_invalidate_compress_pages() to use filemap_get_folios()

Convert this function to use folios throughout.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Acked-by: Chao Yu <chao@kernel.org>

f2fs: Convert to release_folio

While converting f2fs_release_page() to f2fs_release_folio(), cache the
sb_info so we don't need to retrieve it twice, and remove the redundant
call to set_page_private(). The use of folios should be pushed further
into f2fs from here.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>

f2fs: replace congestion_wait() calls with io_schedule_timeout()

As congestion is no longer tracked, congestion_wait() is effectively
equivalent to io_schedule_timeout().

So introduce f2fs_io_schedule_timeout() which sets TASK_UNINTERRUPTIBLE
and call that instead.

Link: https://lkml.kernel.org/r/164549983744.9187.6425865370954230902.stgit@noble.brown
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Lars Ellenberg <lars.ellenberg@linbit.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Paolo Valente <paolo.valente@linaro.org>
Cc: Philipp Reisner <philipp.reisner@linbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

f2fs: compress: fix to print raw data size in error path of lz4 decompression

In lz4_decompress_pages(), if size of decompressed data is not equal to
expected one, we should print the size rather than size of target buffer
for decompressed data, fix it.

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: Convert invalidatepage to invalidate_folio

This is a minimal change which just accepts the new arguments and passes
the single struct page to the functions which do the work. There is
very little progress here toards making f2fs support large folios.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs

f2fs: move f2fs to use reader-unfair rwsems

f2fs rw_semaphores work better if writers can starve readers,
especially for the checkpoint thread, because writers are strictly
more important than reader threads. This prevents significant priority
inversion between low-priority readers that blocked while trying to
acquire the read lock and a second acquisition of the write lock that
might be blocking high priority work.

Signed-off-by: Tim Murray <timmurray@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: do not bother checkpoint by f2fs_get_node_info

This patch tries to mitigate lock contention between f2fs_write_checkpoint and
f2fs_get_node_info along with nat_tree_lock.

The idea is, if checkpoint is currently running, other threads that try to grab
nat_tree_lock would be better to wait for checkpoint.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix potential deadlock of compress file

There is a potential deadlock between writeback process and a process
performing write_begin() or write_cache_pages() while trying to write
same compress file, but not compressable, as below:

[Process A] - doing checkpoint
[Process B] [Process C]
f2fs_write_cache_pages()
- lock_page() [all pages in cluster, 0-31]
- f2fs_write_multi_pages()
- f2fs_write_raw_pages()
- f2fs_write_single_data_page()
- f2fs_do_write_data_page()
- return -EAGAIN [f2fs_trylock_op() failed]
- unlock_page(page) [e.g., page 0]
- generic_perform_write()
- f2fs_write_begin()
- f2fs_prepare_compress_overwrite()
- prepare_compress_overwrite()
- lock_page() [e.g., page 0]
- lock_page() [e.g., page 1]
- lock_page(page) [e.g., page 0]

Since there is no compress process, it is no longer necessary to hold
locks on every pages in cluster within f2fs_write_raw_pages().

This patch changes f2fs_write_raw_pages() to release all locks first
and then perform write same as the non-compress file in
f2fs_write_cache_pages().

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Hyeong-Jun Kim <hj514.kim@samsung.com>
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: reduce one page array alloc and free when write compressed page

Don't alloc new page pointers array to replace old, just use old, introduce
valid_nr_cpages to indicate valid number of page pointers in array, try to
reduce one page array alloc and free when write compress page.

Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

lib: zstd: Add kernel-specific API

This patch:
- Moves `include/linux/zstd.h` -> `include/linux/zstd_lib.h`
- Updates modified zstd headers to yearless copyright
- Adds a new API in `include/linux/zstd.h` that is functionally
equivalent to the in-use subset of the current API. Functions are
renamed to avoid symbol collisions with zstd, to make it clear it is
not the upstream zstd API, and to follow the kernel style guide.
- Updates all callers to use the new API.

There are no functional changes in this patch. Since there are no
functional change, I felt it was okay to update all the callers in a
single patch. Once the API is approved, the callers are mechanically
changed.

This patch is preparing for the 3rd patch in this series, which updates
zstd to version 1.4.10. Since the upstream zstd API is no longer exposed
to callers, the update can happen transparently.

Signed-off-by: Nick Terrell <terrelln@fb.com>
Tested By: Paul Jones <paul@pauljones.id.au>
Tested-by: Oleksandr Natalenko <oleksandr@natalenko.name>
Tested-by: Sedat Dilek <sedat.dilek@gmail.com> # LLVM/Clang v13.0.0 on x86-64
Tested-by: Jean-Denis Girard <jd.girard@sysnux.pf>

f2fs: compress: fix overwrite may reduce compress ratio unproperly

when overwrite only first block of cluster, since cluster is not full, it
will call f2fs_write_raw_pages when f2fs_write_multi_pages, and cause the
whole cluster become uncompressed eventhough data can be compressed.
this may will make random write bench score reduce a lot.

root# dd if=/dev/zero of=./fio-test bs=1M count=1

root# sync

root# echo 3 > /proc/sys/vm/drop_caches

root# f2fs_io get_cblocks ./fio-test

root# dd if=/dev/zero of=./fio-test bs=4K count=1 oflag=direct conv=notrunc

w/o patch:
root# f2fs_io get_cblocks ./fio-test
189

w/ patch:
root# f2fs_io get_cblocks ./fio-test
192

Signed-off-by: Fengnan Chang <changfengnan@vivo.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: include non-compressed blocks in compr_written_block

Need to include non-compressed blocks in compr_written_block to
estimate average compression ratio more accurately.

Fixes: 5ac443e26a09 ("f2fs: add sysfs nodes to get runtime compression stat")
Cc: stable@vger.kernel.org
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

mm: don't include <linux/blk-cgroup.h> in <linux/backing-dev.h>

There is no need to pull blk-cgroup.h and thus blkdev.h in here, so
break the include chain.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20210920123328.1399408-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>

f2fs: deallocate compressed pages when error happens

In f2fs_write_multi_pages(), f2fs_compress_pages() allocates pages for
compression work in cc->cpages[]. Then, f2fs_write_compressed_pages() initiates
bio submission. But, if there's any error before submitting the IOs like early
f2fs_cp_error(), previously it didn't free cpages by f2fs_compress_free_page().
Let's fix memory leak by putting that just before deallocating cc->cpages.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: do sanity check on cluster

This patch adds f2fs_sanity_check_cluster() to support doing
sanity check on cluster of compressed file, it will be triggered
from below two paths:

- __f2fs_cluster_blocks()
- f2fs_map_blocks(F2FS_GET_BLOCK_FIEMAP)

And it can detect below three kind of cluster insanity status.

C: COMPRESS_ADDR
N: NULL_ADDR or NEW_ADDR
V: valid blkaddr
*: any value

1. [*|C|*|*]
2. [C|*|C|*]
3. [C|N|N|V]

Signed-off-by: Chao Yu <chao@kernel.org>
[Nathan Chancellor: fix missing inline warning]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support fault injection for f2fs_kmem_cache_alloc()

This patch supports to inject fault into f2fs_kmem_cache_alloc().

Usage:
a) echo 32768 > /sys/fs/f2fs/<dev>/inject_type or
b) mount -o fault_type=32768 <dev> <mountpoint>

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: extent cache: support unaligned extent

Compressed inode may suffer read performance issue due to it can not
use extent cache, so I propose to add this unaligned extent support
to improve it.

Currently, it only works in readonly format f2fs image.

Unaligned extent: in one compressed cluster, physical block number
will be less than logical block number, so we add an extra physical
block length in extent info in order to indicate such extent status.

The idea is if one whole cluster blocks are contiguous physically,
once its mapping info was readed at first time, we will cache an
unaligned (or aligned) extent info entry in extent cache, it expects
that the mapping info will be hitted when rereading cluster.

Merge policy:
- Aligned extents can be merged.
- Aligned extent and unaligned extent can not be merged.

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: add compress_inode to cache compressed blocks

Support to use address space of inner inode to cache compressed block,
in order to improve cache hit ratio of random read.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce FI_COMPRESS_RELEASED instead of using IMMUTABLE bit

Once we release compressed blocks, we used to set IMMUTABLE bit. But it turned
out it disallows every fs operations which we don't need for compression.

Let's just prevent writing data only.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: remove unneeded preallocation

We will reserve iblocks for compression saved, so during compressed
cluster overwrite, we don't need to preallocate blocks for later
write.

In addition, it adds a bug_on to detect wrong reserved iblock number
in __f2fs_cluster_blocks().

Bug fix in the original patch by Jaegeuk:
If we released compressed blocks having an immutable bit, we can see less
number of compressed block addresses. Let's fix wrong BUG_ON.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: let's allow compression for mmap files

This patch allows to compress mmap files. E.g., for so files.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: clean up parameter of __f2fs_cluster_blocks()

Previously, in order to reuse __f2fs_cluster_blocks(),
f2fs_is_compressed_cluster() assigned a compress_ctx type variable,
which is used to pass few parameters (cc.inode, cc.cluster_size,
cc.cluster_idx), it's wasteful to allocate such large space in stack.

Let's clean up parameters of __f2fs_cluster_blocks() to avoid that.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: restructure f2fs page.private layout

Restruct f2fs page private layout for below reasons:

There are some cases that f2fs wants to set a flag in a page to
indicate a specified status of page:
a) page is in transaction list for atomic write
b) page contains dummy data for aligned write
c) page is migrating for GC
d) page contains inline data for inline inode flush
e) page belongs to merkle tree, and is verified for fsverity
f) page is dirty and has filesystem/inode reference count for writeback
g) page is temporary and has decompress io context reference for compression

There are existed places in page structure we can use to store
f2fs private status/data:
- page.flags: PG_checked, PG_private
- page.private

However it was a mess when we using them, which may cause potential
confliction:
page.private PG_private PG_checked page._refcount (+1 at most)
a) -1 set +1
b) -2 set
c), d), e) set
f) 0 set +1
g) pointer set

The other problem is page.flags has no free slot, if we can avoid set
zero to page.private and set PG_private flag, then we use non-zero value
to indicate PG_private status, so that we may have chance to reclaim
PG_private slot for other usage. [1]

The other concern is f2fs has bad scalability in aspect of indicating
more page status.

So in this patch, let's restructure f2fs' page.private as below to
solve above issues:

Layout A: lowest bit should be 1
| bit0 = 1 | bit1 | bit2 | ... | bit MAX | private data .... |
bit 0 PAGE_PRIVATE_NOT_POINTER
bit 1 PAGE_PRIVATE_ATOMIC_WRITE
bit 2 PAGE_PRIVATE_DUMMY_WRITE
bit 3 PAGE_PRIVATE_ONGOING_MIGRATION
bit 4 PAGE_PRIVATE_INLINE_INODE
bit 5 PAGE_PRIVATE_REF_RESOURCE
bit 6- f2fs private data

Layout B: lowest bit should be 0
page.private is a wrapped pointer.

After the change:
page.private PG_private PG_checked page._refcount (+1 at most)
a) 11 set +1
b) 101 set +1
c) 1001 set +1
d) 10001 set +1
e) set
f) 100001 set +1
g) pointer set +1

[1] https://lore.kernel.org/linux-f2fs-devel/20210422154705.GO3596236@casper.infradead.org/T/#u

Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add cp_error check in f2fs_write_compressed_pages

This patch adds cp_error check in f2fs_write_compressed_pages() like we did
in f2fs_write_single_data_page()

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: rename __cluster_may_compress

This patch renames __cluster_may_compress() to cluster_has_invalid_data() for
better readability.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix to assign cc.cluster_idx correctly

In f2fs_destroy_compress_ctx(), after f2fs_destroy_compress_ctx(),
cc.cluster_idx will be cleared w/ NULL_CLUSTER, f2fs_cluster_blocks()
may check wrong cluster metadata, fix it.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix race condition of overwrite vs truncate

pos_fsstress testcase complains a panic as belew:

------------[ cut here ]------------
kernel BUG at fs/f2fs/compress.c:1082!
invalid opcode: 0000 [#1] SMP PTI
CPU: 4 PID: 2753477 Comm: kworker/u16:2 Tainted: G OE 5.12.0-rc1-custom #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014
Workqueue: writeback wb_workfn (flush-252:16)
RIP: 0010:prepare_compress_overwrite+0x4c0/0x760 [f2fs]
Call Trace:
f2fs_prepare_compress_overwrite+0x5f/0x80 [f2fs]
f2fs_write_cache_pages+0x468/0x8a0 [f2fs]
f2fs_write_data_pages+0x2a4/0x2f0 [f2fs]
do_writepages+0x38/0xc0
__writeback_single_inode+0x44/0x2a0
writeback_sb_inodes+0x223/0x4d0
__writeback_inodes_wb+0x56/0xf0
wb_writeback+0x1dd/0x290
wb_workfn+0x309/0x500
process_one_work+0x220/0x3c0
worker_thread+0x53/0x420
kthread+0x12f/0x150
ret_from_fork+0x22/0x30

The root cause is truncate() may race with overwrite as below,
so that one reference count left in page can not guarantee the
page attaching in mapping tree all the time, after truncation,
later find_lock_page() may return NULL pointer.

- prepare_compress_overwrite
- f2fs_pagecache_get_page
- unlock_page
- f2fs_setattr
- truncate_setsize
- truncate_inode_page
- delete_from_page_cache
- find_lock_page

Fix this by avoiding referencing updated page.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix to free compress page correctly

In error path of f2fs_write_compressed_pages(), it needs to call
f2fs_compress_free_page() to release temporary page.

Fixes: 5e6bbde95982 ("f2fs: introduce mempool for {,de}compress intermediate page allocation")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: remove unneed check condition

In only call path of __cluster_may_compress(), __f2fs_write_data_pages()
has checked SBI_POR_DOING condition, and also cluster_may_compress()
has checked CP_ERROR_FLAG condition, so remove redundant check condition
in __cluster_may_compress() for cleanup.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up left deprecated IO trace codes

Commit d5f7bc0064e0 ("f2fs: deprecate f2fs_trace_io") left some
dead codes, delete them.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add sysfs nodes to get runtime compression stat

I've added new sysfs nodes to show runtime compression stat since mount.
compr_written_block - show the block count written after compression
compr_saved_block - show the saved block count with compression
compr_new_inode - show the count of inode newly enabled for compression

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix potential deadlock

generic/269 reports a hangtask issue, the root cause is ABBA deadlock
described as below:

Thread A Thread B
- down_write(&sbi->gc_lock) -- A
- f2fs_write_data_pages
- lock all pages in cluster -- B
- f2fs_write_multi_pages
- f2fs_write_raw_pages
- f2fs_write_single_data_page
- f2fs_balance_fs
- down_write(&sbi->gc_lock) -- A
- f2fs_gc
- do_garbage_collect
- ra_data_block
- pagecache_get_page -- B

To fix this, it needs to avoid calling f2fs_balance_fs() if there is
still cluster pages been locked in context of cluster writeback, so
instead, let's call f2fs_balance_fs() in the end of
f2fs_write_raw_pages() when all cluster pages were unlocked.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up post-read processing

Rework the post-read processing logic to be much easier to understand.

At least one bug is fixed by this: if an I/O error occurred when reading
from disk, decryption and verity would be performed on the uninitialized
data, causing misleading messages in the kernel log.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: support compress level

Expand 'compress_algorithm' mount option to accept parameter as format of
<algorithm>:<level>, by this way, it gives a way to allow user to do more
specified config on lz4 and zstd compression level, then f2fs compression
can provide higher compress ratio.

In order to set compress level for lz4 algorithm, it needs to set
CONFIG_LZ4HC_COMPRESS and CONFIG_F2FS_FS_LZ4HC config to enable lz4hc
compress algorithm.

CR and performance number on lz4/lz4hc algorithm:

dd if=enwik9 of=compressed_file conv=fsync

Original blocks: 244382

lz4 lz4hc-9
compressed blocks 170647 163270
compress ratio 69.8% 66.8%
speed 16.4207 s, 60.9 MB/s 26.7299 s, 37.4 MB/s

compress ratio = after / before

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix compression chksum

This patch addresses minor issues in compression chksum.

Fixes: b28f047b28c5 ("f2fs: compress: support chksum")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix race of pending_pages in decompression

I found out f2fs_free_dic() is invoked in a wrong timing, but
f2fs_verify_bio() still needed the dic info and it triggered the
below kernel panic. It has been caused by the race condition of
pending_pages value between decompression and verity logic, when
the same compression cluster had been split in different bios.
By split bios, f2fs_verify_bio() ended up with decreasing
pending_pages value before it is reset to nr_cpages by
f2fs_decompress_pages() and caused the kernel panic.

[ 4416.564763] Unable to handle kernel NULL pointer dereference
at virtual address 0000000000000000
...
[ 4416.896016] Workqueue: fsverity_read_queue f2fs_verity_work
[ 4416.908515] pc : fsverity_verify_page+0x20/0x78
[ 4416.913721] lr : f2fs_verify_bio+0x11c/0x29c
[ 4416.913722] sp : ffffffc019533cd0
[ 4416.913723] x29: ffffffc019533cd0 x28: 0000000000000402
[ 4416.913724] x27: 0000000000000001 x26: 0000000000000100
[ 4416.913726] x25: 0000000000000001 x24: 0000000000000004
[ 4416.913727] x23: 0000000000001000 x22: 0000000000000000
[ 4416.913728] x21: 0000000000000000 x20: ffffffff2076f9c0
[ 4416.913729] x19: ffffffff2076f9c0 x18: ffffff8a32380c30
[ 4416.913731] x17: ffffffc01f966d97 x16: 0000000000000298
[ 4416.913732] x15: 0000000000000000 x14: 0000000000000000
[ 4416.913733] x13: f074faec89ffffff x12: 0000000000000000
[ 4416.913734] x11: 0000000000001000 x10: 0000000000001000
[ 4416.929176] x9 : ffffffff20d1f5c7 x8 : 0000000000000000
[ 4416.929178] x7 : 626d7464ff286b6b x6 : ffffffc019533ade
[ 4416.929179] x5 : 000000008049000e x4 : ffffffff2793e9e0
[ 4416.929180] x3 : 000000008049000e x2 : ffffff89ecfa74d0
[ 4416.929181] x1 : 0000000000000c40 x0 : ffffffff2076f9c0
[ 4416.929184] Call trace:
[ 4416.929187] fsverity_verify_page+0x20/0x78
[ 4416.929189] f2fs_verify_bio+0x11c/0x29c
[ 4416.929192] f2fs_verity_work+0x58/0x84
[ 4417.050667] process_one_work+0x270/0x47c
[ 4417.055354] worker_thread+0x27c/0x4d8
[ 4417.059784] kthread+0x13c/0x320
[ 4417.063693] ret_from_fork+0x10/0x18

Chao pointed this can happen by the below race condition.

Thread A f2fs_post_read_wq fsverity_wq
- f2fs_read_multi_pages()
- f2fs_alloc_dic
- dic->pending_pages = 2
- submit_bio()
- submit_bio()
- f2fs_post_read_work() handle first bio
- f2fs_decompress_work()
- __read_end_io()
- f2fs_decompress_pages()
- dic->pending_pages--
- enqueue f2fs_verity_work()
- f2fs_verity_work() handle first bio
- f2fs_verify_bio()
- dic->pending_pages--
- f2fs_post_read_work() handle second bio
- f2fs_decompress_work()
- enqueue f2fs_verity_work()
- f2fs_verify_pages()
- f2fs_free_dic()

- f2fs_verity_work() handle second bio
- f2fs_verfy_bio()
- use-after-free on dic

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add compress_mode mount option

We will add a new "compress_mode" mount option to control file
compression mode. This supports "fs" and "user". In "fs" mode (default),
f2fs does automatic compression on the compression enabled files.
In "user" mode, f2fs disables the automaic compression and gives the
user discretion of choosing the target file and the timing. It means
the user can do manual compression/decompression on the compression
enabled files using ioctls.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: support chksum

This patch supports to store chksum value with compressed
data, and verify the integrality of compressed data while
reading the data.

The feature can be enabled through specifying mount option
'compress_chksum'.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix slab leak of rpages pointer

This fixes the below mem leak.

[ 130.157600] =============================================================================
[ 130.159662] BUG f2fs_page_array_entry-252:16 (Tainted: G W O ): Objects remaining in f2fs_page_array_entry-252:16 on __kmem_cache_shutdown()
[ 130.162742] -----------------------------------------------------------------------------
[ 130.162742]
[ 130.164979] Disabling lock debugging due to kernel taint
[ 130.166188] INFO: Slab 0x000000009f5a52d2 objects=22 used=4 fp=0x00000000ba72c3e9 flags=0xfffffc0010200
[ 130.168269] CPU: 7 PID: 3560 Comm: umount Tainted: G B W O 5.9.0-rc4+ #35
[ 130.170019] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
[ 130.171941] Call Trace:
[ 130.172528] dump_stack+0x74/0x9a
[ 130.173298] slab_err+0xb7/0xdc
[ 130.174044] ? kernel_poison_pages+0xc0/0xc0
[ 130.175065] ? on_each_cpu_cond_mask+0x48/0x90
[ 130.176096] __kmem_cache_shutdown.cold+0x34/0x141
[ 130.177190] kmem_cache_destroy+0x59/0x100
[ 130.178223] f2fs_destroy_page_array_cache+0x15/0x20 [f2fs]
[ 130.179527] f2fs_put_super+0x1bc/0x380 [f2fs]
[ 130.180538] generic_shutdown_super+0x72/0x110
[ 130.181547] kill_block_super+0x27/0x50
[ 130.182438] kill_f2fs_super+0x76/0xe0 [f2fs]
[ 130.183448] deactivate_locked_super+0x3b/0x80
[ 130.184456] deactivate_super+0x3e/0x50
[ 130.185363] cleanup_mnt+0x109/0x160
[ 130.186179] __cleanup_mnt+0x12/0x20
[ 130.187003] task_work_run+0x70/0xb0
[ 130.187841] exit_to_user_mode_prepare+0x18f/0x1b0
[ 130.188917] syscall_exit_to_user_mode+0x31/0x170
[ 130.189989] do_syscall_64+0x45/0x90
[ 130.190828] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 130.191986] RIP: 0033:0x7faf868ea2eb
[ 130.192815] Code: 7b 0c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 90 f3 0f 1e fa 31 f6 e9 05 00 00 00 0f 1f 44 00 00 f3 0f 1e fa b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 75 7b 0c 00 f7 d8 64 89 01
[ 130.196872] RSP: 002b:00007fffb7edb478 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 130.198494] RAX: 0000000000000000 RBX: 00007faf86a18204 RCX: 00007faf868ea2eb
[ 130.201021] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055971df71c50
[ 130.203415] RBP: 000055971df71a40 R08: 0000000000000000 R09: 00007fffb7eda1f0
[ 130.205772] R10: 00007faf86a04339 R11: 0000000000000246 R12: 000055971df71c50
[ 130.208150] R13: 0000000000000000 R14: 000055971df71b38 R15: 0000000000000000
[ 130.210515] INFO: Object 0x00000000a980843a @offset=744
[ 130.212476] INFO: Allocated in page_array_alloc+0x3d/0xe0 [f2fs] age=1572 cpu=0 pid=3297
[ 130.215030] __slab_alloc+0x20/0x40
[ 130.216566] kmem_cache_alloc+0x2a0/0x2e0
[ 130.218217] page_array_alloc+0x3d/0xe0 [f2fs]
[ 130.219940] f2fs_init_compress_ctx+0x1f/0x40 [f2fs]
[ 130.221736] f2fs_write_cache_pages+0x3db/0x860 [f2fs]
[ 130.223591] f2fs_write_data_pages+0x2c9/0x300 [f2fs]
[ 130.225414] do_writepages+0x43/0xd0
[ 130.226907] __filemap_fdatawrite_range+0xd5/0x110
[ 130.228632] filemap_write_and_wait_range+0x48/0xb0
[ 130.230336] __generic_file_write_iter+0x18a/0x1d0
[ 130.232035] f2fs_file_write_iter+0x226/0x550 [f2fs]
[ 130.233737] new_sync_write+0x113/0x1a0
[ 130.235204] vfs_write+0x1a6/0x200
[ 130.236579] ksys_write+0x67/0xe0
[ 130.237898] __x64_sys_write+0x1a/0x20
[ 130.239309] do_syscall_64+0x38/0x90

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: introduce cic/dic slab cache

Add two slab caches: "f2fs_cic_entry" and "f2fs_dic_entry" for memory
allocation of compress_io_ctx and decompress_io_ctx structure.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: introduce page array slab cache

Add a per-sbi slab cache "f2fs_page_array_entry-%u:%u" for memory
allocation of page pointer array in compress context.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
[Jaegeuk Kim: Fix wrong memory allocation]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: change virtual mapping way for compression pages

By profiling f2fs compression works, I've found vmap() callings have
unexpected hikes in the execution time in our test environment and
those are bottlenecks of f2fs decompression path. Changing these with
vm_map_ram(), we can enhance f2fs decompression speed pretty much.

[Verification]
Android Pixel 3(ARM64, 6GB RAM, 128GB UFS)
Turned on only 0-3 little cores(at 1.785GHz)

dd if=/dev/zero of=dummy bs=1m count=1000
echo 3 > /proc/sys/vm/drop_caches
dd if=dummy of=/dev/zero bs=512k

- w/o compression -
1048576000 bytes (0.9 G) copied, 2.082554 s, 480 M/s
1048576000 bytes (0.9 G) copied, 2.081634 s, 480 M/s
1048576000 bytes (0.9 G) copied, 2.090861 s, 478 M/s

- before patch -
1048576000 bytes (0.9 G) copied, 7.407527 s, 135 M/s
1048576000 bytes (0.9 G) copied, 7.283734 s, 137 M/s
1048576000 bytes (0.9 G) copied, 7.291508 s, 137 M/s

- after patch -
1048576000 bytes (0.9 G) copied, 1.998959 s, 500 M/s
1048576000 bytes (0.9 G) copied, 1.987554 s, 503 M/s
1048576000 bytes (0.9 G) copied, 1.986380 s, 503 M/s

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: allocate proper size memory for zstd decompress

As 5kft <5kft@5kft.org> reported:

kworker/u9:3: page allocation failure: order:9, mode:0x40c40(GFP_NOFS|__GFP_COMP), nodemask=(null),cpuset=/,mems_allowed=0
CPU: 3 PID: 8168 Comm: kworker/u9:3 Tainted: G C 5.8.3-sunxi #trunk
Hardware name: Allwinner sun8i Family
Workqueue: f2fs_post_read_wq f2fs_post_read_work
[<c010d6d5>] (unwind_backtrace) from [<c0109a55>] (show_stack+0x11/0x14)
[<c0109a55>] (show_stack) from [<c056d489>] (dump_stack+0x75/0x84)
[<c056d489>] (dump_stack) from [<c0243b53>] (warn_alloc+0xa3/0x104)
[<c0243b53>] (warn_alloc) from [<c024473b>] (__alloc_pages_nodemask+0xb87/0xc40)
[<c024473b>] (__alloc_pages_nodemask) from [<c02267c5>] (kmalloc_order+0x19/0x38)
[<c02267c5>] (kmalloc_order) from [<c02267fd>] (kmalloc_order_trace+0x19/0x90)
[<c02267fd>] (kmalloc_order_trace) from [<c047c665>] (zstd_init_decompress_ctx+0x21/0x88)
[<c047c665>] (zstd_init_decompress_ctx) from [<c047e9cf>] (f2fs_decompress_pages+0x97/0x228)
[<c047e9cf>] (f2fs_decompress_pages) from [<c045d0ab>] (__read_end_io+0xfb/0x130)
[<c045d0ab>] (__read_end_io) from [<c045d141>] (f2fs_post_read_work+0x61/0x84)
[<c045d141>] (f2fs_post_read_work) from [<c0130b2f>] (process_one_work+0x15f/0x3b0)
[<c0130b2f>] (process_one_work) from [<c0130e7b>] (worker_thread+0xfb/0x3e0)
[<c0130e7b>] (worker_thread) from [<c0135c3b>] (kthread+0xeb/0x10c)
[<c0135c3b>] (kthread) from [<c0100159>]

zstd may allocate large size memory for {,de}compression, it may cause
file copy failure on low-end device which has very few memory.

For decompression, let's just allocate proper size memory based on current
file's cluster size instead of max cluster size.

Reported-by: 5kft <5kft@5kft.org>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: use more readable atomic_t type for {cic,dic}.ref

refcount_t type variable should never be less than one, so it's a
little bit hard to understand when we use it to indicate pending
compressed page count, let's change to use atomic_t for better
readability.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: remove unneeded code

- f2fs_write_multi_pages
- f2fs_compress_pages
- init_compress_ctx
- compress_pages
- destroy_compress_ctx --- 1
- f2fs_write_compressed_pages
- destroy_compress_ctx --- 2

destroy_compress_ctx() in f2fs_write_multi_pages() is redundant, remove
it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: delay temp page allocation

Currently, we allocate temp pages which is used to pad hole in
cluster during read IO submission, it may take long time before
releasing them in f2fs_decompress_pages(), since they are only
used as temp output buffer in decompression context, so let's
just do the allocation in that context to reduce time of memory
pool resource occupation.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix to avoid memory leak on cc->cpages

Memory allocated for storing compressed pages' poitner should be
released after f2fs_write_compressed_pages(), otherwise it will
cause memory leak issue.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add inline encryption support

Wire up f2fs to support inline encryption via the helper functions which
fs/crypto/ now provides. This includes:

- Adding a mount option 'inlinecrypt' which enables inline encryption
on encrypted files where it can be used.

- Setting the bio_crypt_ctx on bios that will be submitted to an
inline-encrypted file.

- Not adding logically discontiguous data to bios that will be submitted
to an inline-encrypted file.

- Not doing filesystem-layer crypto on inline-encrypted files.

This patch includes a fix for a race during IPU by
Sahitya Tummala <stummala@codeaurora.org>

Signed-off-by: Satya Tangirala <satyat@google.com>
Acked-by: Jaegeuk Kim <jaegeuk@kernel.org>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200702015607.1215430-4-satyat@google.com
Co-developed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>

f2fs: fix to wait GCed compressed page writeback

like we did for encrypted page.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix an oops in f2fs_is_compressed_page

This patch is to fix a crash:

#3 [ffffb6580689f898] oops_end at ffffffffa2835bc2
#4 [ffffb6580689f8b8] no_context at ffffffffa28766e7
#5 [ffffb6580689f920] async_page_fault at ffffffffa320135e
[exception RIP: f2fs_is_compressed_page+34]
RIP: ffffffffa2ba83a2 RSP: ffffb6580689f9d8 RFLAGS: 00010213
RAX: 0000000000000001 RBX: fffffc0f50b34bc0 RCX: 0000000000002122
RDX: 0000000000002123 RSI: 0000000000000c00 RDI: fffffc0f50b34bc0
RBP: ffff97e815a40178 R8: 0000000000000000 R9: ffff97e83ffc9000
R10: 0000000000032300 R11: 0000000000032380 R12: ffffb6580689fa38
R13: fffffc0f50b34bc0 R14: ffff97e825cbd000 R15: 0000000000000c00
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#6 [ffffb6580689f9d8] __is_cp_guaranteed at ffffffffa2b7ea98
#7 [ffffb6580689f9f0] f2fs_submit_page_write at ffffffffa2b81a69
#8 [ffffb6580689fa30] f2fs_do_write_meta_page at ffffffffa2b99777
#9 [ffffb6580689fae0] __f2fs_write_meta_page at ffffffffa2b75f1a
#10 [ffffb6580689fb18] f2fs_sync_meta_pages at ffffffffa2b77466
#11 [ffffb6580689fc98] do_checkpoint at ffffffffa2b78e46
#12 [ffffb6580689fd88] f2fs_write_checkpoint at ffffffffa2b79c29
#13 [ffffb6580689fdd0] f2fs_sync_fs at ffffffffa2b69d95
#14 [ffffb6580689fe20] sync_filesystem at ffffffffa2ad2574
#15 [ffffb6580689fe30] generic_shutdown_super at ffffffffa2a9b582
#16 [ffffb6580689fe48] kill_block_super at ffffffffa2a9b6d1
#17 [ffffb6580689fe60] kill_f2fs_super at ffffffffa2b6abe1
#18 [ffffb6580689fea0] deactivate_locked_super at ffffffffa2a9afb6
#19 [ffffb6580689feb8] cleanup_mnt at ffffffffa2abcad4
#20 [ffffb6580689fee0] task_work_run at ffffffffa28bca28
#21 [ffffb6580689ff00] exit_to_usermode_loop at ffffffffa28050b7
#22 [ffffb6580689ff38] do_syscall_64 at ffffffffa280560e
#23 [ffffb6580689ff50] entry_SYSCALL_64_after_hwframe at ffffffffa320008c

This occurred when umount f2fs if enable F2FS_FS_COMPRESSION
with F2FS_IO_TRACE. Fixes it by adding IS_IO_TRACED_PAGE to check
validity of pid for page_private.

Signed-off-by: Yu Changchun <yuchangchun1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to check page dirty status before writeback

In f2fs_write_raw_pages(), we need to check page dirty status before
writeback, because there could be a racer (e.g. reclaimer) helps
writebacking the dirty page.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove the unused compr parameter

The parameter compr is unused in the f2fs_cluster_blocks function
so we no longer need to pass it as a parameter.

Signed-off-by: Wang Xiaojun <wangxiaojun11@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: shrink node_write lock coverage

- to avoid race between checkpoint and quota file writeback, it
just needs to hold read lock of node_write in writeback path.
- node_write lock has covered all LFS data write paths, it's not
necessary, we only need to hold node_write lock at write path of
quota file.

This refactors commit ca7f76e68074 ("f2fs: fix wrong discard space").

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: add prefix for exported symbols

to avoid polluting global symbol namespace.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: avoid checkpatch error

ERROR:INITIALISED_STATIC: do not initialise statics to NULL

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: remove unused parameter of f2fs_put_rpages_mapping()

Just cleanup, no logic change.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: don't compress any datas after cp stop

While compressed data writeback, we need to drop dirty pages like we did
for non-compressed pages if cp stops, however it's not needed to compress
any data in such case, so let's detect cp stop condition in
cluster_may_compress() to avoid redundant compressing and let following
f2fs_write_raw_pages() drops dirty pages correctly.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix zstd data corruption

During zstd compression, ZSTD_endStream() may return non-zero value
because distination buffer is full, but there is still compressed data
remained in intermediate buffer, it means that zstd algorithm can not
save at last one block space, let's just writeback raw data instead of
compressed one, this can fix data corruption when decompressing
incomplete stored compression data.

Fixes: 50cfa66f0de0 ("f2fs: compress: support zstd compress algorithm")
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: let lz4 compressor handle output buffer budget properly

Commonly, in order to handle lz4 worst compress case, caller should
allocate buffer with size of LZ4_compressBound(inputsize) for target
compressed data storing, however in this case, if caller didn't
allocate enough space, lz4 compressor still can handle output buffer
budget properly, and end up compressing when left space in output
buffer is not enough.

So we don't have to allocate buffer with size for worst case, then
we can avoid 2 * 4KB size intermediate buffer allocation when
log_cluster_size is 2, and avoid unnecessary compressing work of
compressor if we can not save at least 4KB space.

Suggested-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: support lzo-rle compress algorithm

LZO-RLE extension (run length encoding) was introduced to improve
performance of LZO algorithm in scenario of data contains many zeros,
zram has changed to use this extended algorithm by default, this
patch adds to support this algorithm extension, to enable this
extension, it needs to enable F2FS_FS_LZO and F2FS_FS_LZORLE config,
and specifies "compress_algorithm=lzo-rle" mountoption.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce mempool for {,de}compress intermediate page allocation

If compression feature is on, in scenario of no enough free memory,
page refault ratio is higher than before, the root cause is:
- {,de}compression flow needs to allocate intermediate pages to store
compressed data in cluster, so during their allocation, vm may reclaim
mmaped pages.
- if above reclaimed pages belong to compressed cluster, during its
refault, it may cause more intermediate pages allocation, result in
reclaiming more mmaped pages.

So this patch introduces a mempool for intermediate page allocation,
in order to avoid high refault ratio, by default, number of
preallocated page in pool is 512, user can change the number by
assigning 'num_compress_pages' parameter during module initialization.

Ma Feng found warnings in the original patch and fixed like below.

Fix the following sparse warning:
fs/f2fs/compress.c:501:5: warning: symbol 'num_compress_pages' was not declared.
Should it be static?
fs/f2fs/compress.c:530:6: warning: symbol 'f2fs_compress_free_page' was not
declared. Should it be static?

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Ma Feng <mafeng.ma@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support partial truncation on compressed inode

Supports to truncate compressed/normal cluster partially on compressed
inode.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix quota_sync failure due to f2fs_lock_op

f2fs_quota_sync() uses f2fs_lock_op() before flushing dirty pages, but
f2fs_write_data_page() returns EAGAIN.
Likewise dentry blocks, we can just bypass getting the lock, since quota
blocks are also maintained by checkpoint.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to verify tpage before releasing in f2fs_free_dic()

In below error path, tpages[i] could be NULL, fix to check it before
releasing it.
- f2fs_read_multi_pages
- f2fs_alloc_dic
- f2fs_free_dic

Fixes: 61fbae2b2b12 ("f2fs: fix to avoid NULL pointer dereference")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up dic->tpages assignment

Just cleanup, no logic change.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: support zstd compress algorithm

Add zstd compress algorithm support, use "compress_algorithm=zstd"
mountoption to enable it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: add .{init,destroy}_decompress_ctx callback

Add below two callback interfaces in struct f2fs_compress_ops:

int (*init_decompress_ctx)(struct decompress_io_ctx *dic);
void (*destroy_decompress_ctx)(struct decompress_io_ctx *dic);

Which will be used by zstd compress algorithm later.

In addition, this patch adds callback function pointer check, so that
specified algorithm can avoid defining unneeded functions.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: compress: fix to call missing destroy_compress_ctx()

Otherwise, it will cause memory leak.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up {cic,dic}.ref handling

{cic,dic}.ref should be initialized to number of compressed pages,
let's initialize it directly rather than doing w/
f2fs_set_compressed_page().

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix NULL pointer dereference in f2fs_verity_work()

If both compression and fsverity feature is on, generic/572 will
report below NULL pointer dereference bug.

BUG: kernel NULL pointer dereference, address: 0000000000000018
RIP: 0010:f2fs_verity_work+0x60/0x90 [f2fs]
#PF: supervisor read access in kernel mode
Workqueue: fsverity_read_queue f2fs_verity_work [f2fs]
RIP: 0010:f2fs_verity_work+0x60/0x90 [f2fs]
Call Trace:
process_one_work+0x16c/0x3f0
worker_thread+0x4c/0x440
? rescuer_thread+0x350/0x350
kthread+0xf8/0x130
? kthread_unpark+0x70/0x70
ret_from_fork+0x35/0x40

There are two issue in f2fs_verity_work():
- it needs to traverse and verify all pages in bio.
- if pages in bio belong to non-compressed cluster, accessing
decompress IO context stored in page private will cause NULL
pointer dereference.

Fix them.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to clear PG_error if fsverity failed

In f2fs_decompress_end_io(), we should clear PG_error flag before page
unlock, otherwise reread will fail due to the flag as described in
commit fb7d70db305a ("f2fs: clear PageError on the read path").

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix potential deadlock on compressed quota file

generic/232 reports below deadlock:

fsstress D 0 96980 96969 0x00084000
Call Trace:
schedule+0x4a/0xb0
io_schedule+0x12/0x40
__lock_page+0x127/0x1d0
pagecache_get_page+0x1d8/0x250
prepare_compress_overwrite+0xe0/0x490 [f2fs]
f2fs_prepare_compress_overwrite+0x5d/0x80 [f2fs]
f2fs_write_begin+0x833/0xb90 [f2fs]
f2fs_quota_write+0x145/0x1e0 [f2fs]
write_blk+0x36/0x80 [quota_tree]
do_insert_tree+0x2ac/0x4a0 [quota_tree]
do_insert_tree+0x26e/0x4a0 [quota_tree]
qtree_write_dquot+0x70/0x190 [quota_tree]
v2_write_dquot+0x43/0x90 [quota_v2]
dquot_acquire+0x77/0x100
f2fs_dquot_acquire+0x2f/0x60 [f2fs]
dqget+0x310/0x450
dquot_transfer+0xb2/0x120
f2fs_setattr+0x11a/0x4a0 [f2fs]
notify_change+0x349/0x480
chown_common+0x168/0x1c0
do_fchownat+0xbc/0xf0
__x64_sys_lchown+0x21/0x30
do_syscall_64+0x5f/0x220
entry_SYSCALL_64_after_hwframe+0x44/0xa9

task PC stack pid father
kworker/u256:0 D 0 103444 2 0x80084000
Workqueue: writeback wb_workfn (flush-251:1)
Call Trace:
schedule+0x4a/0xb0
schedule_timeout+0x15e/0x2f0
io_schedule_timeout+0x19/0x40
congestion_wait+0x7e/0x120
f2fs_write_multi_pages+0x12a/0x840 [f2fs]
f2fs_write_cache_pages+0x48f/0x790 [f2fs]
f2fs_write_data_pages+0x2db/0x330 [f2fs]
do_writepages+0x1a/0x60
__writeback_single_inode+0x3d/0x340
writeback_sb_inodes+0x225/0x4a0
wb_writeback+0xf7/0x320
wb_workfn+0xba/0x470
process_one_work+0x16c/0x3f0
worker_thread+0x4c/0x440
kthread+0xf8/0x130
ret_from_fork+0x35/0x40

fsstress D 0 5277 5266 0x00084000
Call Trace:
schedule+0x4a/0xb0
rwsem_down_write_slowpath+0x29d/0x540
block_operations+0x105/0x360 [f2fs]
f2fs_write_checkpoint+0x101/0x1010 [f2fs]
f2fs_sync_fs+0xa8/0x130 [f2fs]
f2fs_do_sync_file+0x1ad/0x890 [f2fs]
do_fsync+0x38/0x60
__x64_sys_fdatasync+0x13/0x20
do_syscall_64+0x5f/0x220
entry_SYSCALL_64_after_hwframe+0x44/0xa9

The root cause is there is potential deadlock between quota data
update and writeback.

Kworker Thread B Thread C
- f2fs_write_cache_pages
- lock whole cluster --- A
- f2fs_write_multi_pages
- f2fs_write_raw_pages
- f2fs_write_single_data_page
- f2fs_do_write_data_page
- f2fs_setattr
- f2fs_lock_op --- B
- f2fs_write_checkpoint
- block_operations
- f2fs_lock_all --- B
- dquot_transfer
- f2fs_quota_write
- f2fs_prepare_compress_overwrite
- pagecache_get_page --- A
- f2fs_trylock_op failed --- B
- congestion_wait
- goto rewrite

To fix this issue, during quota file writeback, just redirty all pages
left in cluster rather holding pages' lock in cluster and looping retrying
lock cp_rwsem.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to account compressed blocks in f2fs_compressed_blocks()

por_fsstress reports inconsistent status in orphan inode, the root cause
of this is in f2fs_write_raw_pages() we decrease i_compr_blocks incorrectly
due to wrong calculation in f2fs_compressed_blocks().

So this patch exposes below two functions based on __f2fs_cluster_blocks:
- f2fs_compressed_blocks: get count of compressed blocks in compressed cluster
- f2fs_cluster_blocks: get count of valid blocks (including reserved blocks)
in compressed cluster.

Then use f2fs_compress_blocks() to get correct compressed blocks count in
f2fs_write_raw_pages().

sanity_check_inode: inode (ino=ad80) hash inconsistent i_compr_blocks:2, i_blocks:1, run fsck to fix

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid triggering IO in write path

If we are in write IO path, we need to avoid using GFP_KERNEL.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: introduce DEFAULT_IO_TIMEOUT

As Geert Uytterhoeven reported:

for parameter HZ/50 in congestion_wait(BLK_RW_ASYNC, HZ/50);

On some platforms, HZ can be less than 50, then unexpected 0 timeout
jiffies will be set in congestion_wait().

This patch introduces a macro DEFAULT_IO_TIMEOUT to wrap a determinate
value with msecs_to_jiffies(20) to instead HZ/50 to avoid such issue.

Quoted from Geert Uytterhoeven:

"A timeout of HZ means 1 second.
HZ/50 means 20 ms, but has the risk of being zero, if HZ < 50.

If you want to use a timeout of 20 ms, you best use msecs_to_jiffies(20),
as that takes care of the special cases, and never returns 0."

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: clean up codes with {f2fs_,}data_blkaddr()

- rename datablock_addr() to data_blkaddr().
- wrap data_blkaddr() with f2fs_data_blkaddr() to clean up
parameters.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid use-after-free in f2fs_write_multi_pages()

In compress cluster, if physical block number is less than logic
page number, race condition will cause use-after-free issue as
described below:

- f2fs_write_compressed_pages
- fio.page = cic->rpages[0];
- f2fs_outplace_write_data
- f2fs_compress_write_end_io
- kfree(cic->rpages);
- kfree(cic);
- fio.page = cic->rpages[1];

f2fs_write_multi_pages+0xfd0/0x1a98
f2fs_write_data_pages+0x74c/0xb5c
do_writepages+0x64/0x108
__writeback_single_inode+0xdc/0x4b8
writeback_sb_inodes+0x4d0/0xa68
__writeback_inodes_wb+0x88/0x178
wb_writeback+0x1f0/0x424
wb_workfn+0x2f4/0x574
process_one_work+0x210/0x48c
worker_thread+0x2e8/0x44c
kthread+0x110/0x120
ret_from_fork+0x10/0x18

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: cover last_disk_size update with spinlock

This change solves below hangtask issue:

INFO: task kworker/u16:1:58 blocked for more than 122 seconds.
Not tainted 5.6.0-rc2-00590-g9983bdae4974e #11
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u16:1 D 0 58 2 0x00000000
Workqueue: writeback wb_workfn (flush-179:0)
Backtrace:
(__schedule) from [<c0913234>] (schedule+0x78/0xf4)
(schedule) from [<c017ec74>] (rwsem_down_write_slowpath+0x24c/0x4c0)
(rwsem_down_write_slowpath) from [<c0915f2c>] (down_write+0x6c/0x70)
(down_write) from [<c0435b80>] (f2fs_write_single_data_page+0x608/0x7ac)
(f2fs_write_single_data_page) from [<c0435fd8>] (f2fs_write_cache_pages+0x2b4/0x7c4)
(f2fs_write_cache_pages) from [<c043682c>] (f2fs_write_data_pages+0x344/0x35c)
(f2fs_write_data_pages) from [<c0267ee8>] (do_writepages+0x3c/0xd4)
(do_writepages) from [<c0310cbc>] (__writeback_single_inode+0x44/0x454)
(__writeback_single_inode) from [<c03112d0>] (writeback_sb_inodes+0x204/0x4b0)
(writeback_sb_inodes) from [<c03115cc>] (__writeback_inodes_wb+0x50/0xe4)
(__writeback_inodes_wb) from [<c03118f4>] (wb_writeback+0x294/0x338)
(wb_writeback) from [<c0312dac>] (wb_workfn+0x35c/0x54c)
(wb_workfn) from [<c014f2b8>] (process_one_work+0x214/0x544)
(process_one_work) from [<c014f634>] (worker_thread+0x4c/0x574)
(worker_thread) from [<c01564fc>] (kthread+0x144/0x170)
(kthread) from [<c01010e8>] (ret_from_fork+0x14/0x2c)

Reported-and-tested-by: Ondřej Jirman <megi@xff.cz>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid potential deadlock

Using f2fs_trylock_op() in f2fs_write_compressed_pages() to avoid potential
deadlock like we did in f2fs_write_single_data_page().

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: recycle unused compress_data.chksum feild

In Struct compress_data, chksum field was never used, remove it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix to avoid NULL pointer dereference

Unable to handle kernel NULL pointer dereference at virtual address 00000000
PC is at f2fs_free_dic+0x60/0x2c8
LR is at f2fs_decompress_pages+0x3c4/0x3e8
f2fs_free_dic+0x60/0x2c8
f2fs_decompress_pages+0x3c4/0x3e8
__read_end_io+0x78/0x19c
f2fs_post_read_work+0x6c/0x94
process_one_work+0x210/0x48c
worker_thread+0x2e8/0x44c
kthread+0x110/0x120
ret_from_fork+0x10/0x18

In f2fs_free_dic(), we can not use f2fs_put_page(,1) to release dic->tpages[i],
as the page's mapping is NULL.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: fix leaking uninitialized memory in compressed clusters

When the compressed data of a cluster doesn't end on a page boundary,
the remainder of the last page must be zeroed in order to avoid leaking
uninitialized memory to disk.

Fixes: 4c8ff7095bef ("f2fs: support data compression")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

f2fs: support data compression

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: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>