Now, we have supported cgroup writeback, it depends on correctly IO
account of specified filesystem.

But in commit d1b3e72d ("f2fs: submit bio of in-place-update pages"),
we split write paths from f2fs_submit_page_mbio() to two:
- f2fs_submit_page_bio() for IPU path
- f2fs_submit_page_bio() for OPU path

But still we account write IO only in f2fs_submit_page_mbio(), result in
incorrect IO account, fix it by adding missing IO account in IPU path.

Fixes: d1b3e72d ("f2fs: submit bio of in-place-update pages")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Below race can cause reversed reference on dirty count, fix it by
relocating __submit_bio() and inc_page_count().

Thread A				Thread B
- f2fs_inplace_write_data
 - f2fs_submit_page_bio
  - __submit_bio
					- f2fs_write_end_io
					 - dec_page_count
  - inc_page_count

Cc: <stable@vger.kernel.org>
Fixes: d1b3e72d ("f2fs: submit bio of in-place-update pages")
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Note that, it requires "f2fs: return correct errno in f2fs_gc".

This adds a lightweight non-persistent snapshotting scheme to f2fs.

To use, mount with the option checkpoint=disable, and to return to
normal operation, remount with checkpoint=enable. If the filesystem
is shut down before remounting with checkpoint=enable, it will revert
back to its apparent state when it was first mounted with
checkpoint=disable. This is useful for situations where you wish to be
able to roll back the state of the disk in case of some critical
failure.
Signed-off-by: NDaniel Rosenberg <drosen@google.com>
[Jaegeuk Kim: use SB_RDONLY instead of MS_RDONLY]
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

When running fault injection test, I hit somewhat wrong behavior in f2fs_gc ->
gc_data_segment():

0. fault injection generated some PageError'ed pages

1. gc_data_segment
 -> f2fs_get_read_data_page(REQ_RAHEAD)

2. move_data_page
 -> f2fs_get_lock_data_page()
  -> f2f_get_read_data_page()
   -> f2fs_submit_page_read()
    -> submit_bio(READ)
  -> return EIO due to PageError
  -> fail to move data
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Normally, DIO uses in-pllace-update, but in LFS mode, f2fs doesn't
allow triggering any in-place-update writes, so we fallback direct
write to buffered write, result in bad performance of large size
write.

This patch adds to support triggering out-place-update for direct IO
to enhance its performance.

Note that it needs to exclude direct read IO during direct write,
since new data writing to new block address will no be valid until
write finished.

storage: zram

time xfs_io -f -d /mnt/f2fs/file -c "pwrite 0 1073741824" -c "fsync"

Before:
real	0m13.061s
user	0m0.327s
sys	0m12.486s

After:
real	0m6.448s
user	0m0.228s
sys	0m6.212s
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Thread A				Thread B
- f2fs_vm_page_mkwrite
					- f2fs_setattr
					 - down_write(i_mmap_sem)
					 - truncate_setsize
					 - f2fs_truncate
					 - up_write(i_mmap_sem)
 - f2fs_reserve_block
 reserve NEW_ADDR
 - skip dirty page due to truncation

1. we don't need to rserve new block address for a truncated page.
2. dn.data_blkaddr is used out of node page lock coverage.

Refactor ->page_mkwrite() flow to fix above issues:
- use __do_map_lock() to avoid racing checkpoint()
- lock data page in prior to dnode page
- cover f2fs_reserve_block with i_mmap_sem lock
- wait page writeback before zeroing page
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

There is one case that we can leave bio in f2fs, result in hanging
page writeback waiter.

Thread A				Thread B
- f2fs_write_cache_pages
 - f2fs_submit_page_write
 page #0 cached in bio #0 of cold log
 - f2fs_submit_page_write
 page #1 cached in bio #1 of warm log
					- f2fs_write_cache_pages
					 - f2fs_submit_page_write
					 bio is full, submit bio #1 contain page #1
 - f2fs_submit_merged_write_cond(, page #1)
 fail to submit bio #0 due to page #1 is not in any cached bios.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This is related to
ee70daab ("xfs: update i_size after unwritten conversion in dio completion")

If we update i_size during dio_write, dio_read can read out stale data, which
breaks xfstests/465.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds to support injecting error for write IO, this can simulate
IO error like fail_make_request or dm_flakey does.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Remove the verbose license text from f2fs files and replace them with
SPDX tags.  This does not change the license of any of the code.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Sometimes, some merged IOs could get a chance to be submitted, resulting in
system hang in shutdown test. This issues IOs all the time after shutdown.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

1. Create a file in an encrypted directory
2. Do GC & drop caches
3. Read stale data before its bio for metapage was not issued yet
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

During GC, for each encrypted block, we will read block synchronously
into meta page, and then submit it into current cold data log area.

So this block read model with 4k granularity can make poor performance,
like migrating non-encrypted block, let's readahead encrypted block
as well to improve migration performance.

To implement this, we choose meta page that its index is old block
address of the encrypted block, and readahead ciphertext into this
page, later, if readaheaded page is still updated, we will load its
data into target meta page, and submit the write IO.

Note that for OPU, truncation, deletion, we need to invalid meta
page after we invalid old block address, to make sure we won't load
invalid data from target meta page during encrypted block migration.

for ((i = 0; i < 1000; i++))
do {
        xfs_io -f /mnt/f2fs/dir/$i -c "pwrite 0 128k" -c "fsync";
} done

for ((i = 0; i < 1000; i+=2))
do {
        rm /mnt/f2fs/dir/$i;
} done

ret = ioctl(fd, F2FS_IOC_GARBAGE_COLLECT, 0);

Before:
              gc-6549  [001] d..1 214682.212797: block_rq_insert: 8,32 RA 32768 () 786400 + 64 [gc]
              gc-6549  [001] d..1 214682.212802: block_unplug: [gc] 1
              gc-6549  [001] .... 214682.213892: block_bio_queue: 8,32 R 67494144 + 8 [gc]
              gc-6549  [001] .... 214682.213899: block_getrq: 8,32 R 67494144 + 8 [gc]
              gc-6549  [001] .... 214682.213902: block_plug: [gc]
              gc-6549  [001] d..1 214682.213905: block_rq_insert: 8,32 R 4096 () 67494144 + 8 [gc]
              gc-6549  [001] d..1 214682.213908: block_unplug: [gc] 1
              gc-6549  [001] .... 214682.226405: block_bio_queue: 8,32 R 67494152 + 8 [gc]
              gc-6549  [001] .... 214682.226412: block_getrq: 8,32 R 67494152 + 8 [gc]
              gc-6549  [001] .... 214682.226414: block_plug: [gc]
              gc-6549  [001] d..1 214682.226417: block_rq_insert: 8,32 R 4096 () 67494152 + 8 [gc]
              gc-6549  [001] d..1 214682.226420: block_unplug: [gc] 1
              gc-6549  [001] .... 214682.226904: block_bio_queue: 8,32 R 67494160 + 8 [gc]
              gc-6549  [001] .... 214682.226910: block_getrq: 8,32 R 67494160 + 8 [gc]
              gc-6549  [001] .... 214682.226911: block_plug: [gc]
              gc-6549  [001] d..1 214682.226914: block_rq_insert: 8,32 R 4096 () 67494160 + 8 [gc]
              gc-6549  [001] d..1 214682.226916: block_unplug: [gc] 1

After:
              gc-5678  [003] .... 214327.025906: block_bio_queue: 8,32 R 67493824 + 8 [gc]
              gc-5678  [003] .... 214327.025908: block_bio_backmerge: 8,32 R 67493824 + 8 [gc]
              gc-5678  [003] .... 214327.025915: block_bio_queue: 8,32 R 67493832 + 8 [gc]
              gc-5678  [003] .... 214327.025917: block_bio_backmerge: 8,32 R 67493832 + 8 [gc]
              gc-5678  [003] .... 214327.025923: block_bio_queue: 8,32 R 67493840 + 8 [gc]
              gc-5678  [003] .... 214327.025925: block_bio_backmerge: 8,32 R 67493840 + 8 [gc]
              gc-5678  [003] .... 214327.025932: block_bio_queue: 8,32 R 67493848 + 8 [gc]
              gc-5678  [003] .... 214327.025934: block_bio_backmerge: 8,32 R 67493848 + 8 [gc]
              gc-5678  [003] .... 214327.025941: block_bio_queue: 8,32 R 67493856 + 8 [gc]
              gc-5678  [003] .... 214327.025943: block_bio_backmerge: 8,32 R 67493856 + 8 [gc]
              gc-5678  [003] .... 214327.025953: block_bio_queue: 8,32 R 67493864 + 8 [gc]
              gc-5678  [003] .... 214327.025955: block_bio_backmerge: 8,32 R 67493864 + 8 [gc]
              gc-5678  [003] .... 214327.025962: block_bio_queue: 8,32 R 67493872 + 8 [gc]
              gc-5678  [003] .... 214327.025964: block_bio_backmerge: 8,32 R 67493872 + 8 [gc]
              gc-5678  [003] .... 214327.025970: block_bio_queue: 8,32 R 67493880 + 8 [gc]
              gc-5678  [003] .... 214327.025972: block_bio_backmerge: 8,32 R 67493880 + 8 [gc]
              gc-5678  [003] .... 214327.026000: block_bio_queue: 8,32 WS 34123776 + 2048 [gc]
              gc-5678  [003] .... 214327.026019: block_getrq: 8,32 WS 34123776 + 2048 [gc]
              gc-5678  [003] d..1 214327.026021: block_rq_insert: 8,32 R 131072 () 67493632 + 256 [gc]
              gc-5678  [003] d..1 214327.026023: block_unplug: [gc] 1
              gc-5678  [003] d..1 214327.026026: block_rq_issue: 8,32 R 131072 () 67493632 + 256 [gc]
              gc-5678  [003] .... 214327.026046: block_plug: [gc]
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

The f2fs_gc() called by f2fs_balance_fs() requires to be called outside of
fi->i_gc_rwsem[WRITE], since f2fs_gc() can try to grab it in a loop.

If it hits the miximum retrials in GC, let's give a chance to release
gc_mutex for a short time in order not to go into live lock in the worst
case.
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This reverts the commit - "b93f7712 - f2fs: remove writepages lock"
to fix the drop in sequential read throughput.

Test: ./tiotest -t 32 -d /data/tio_tmp -f 32 -b 524288 -k 1 -k 3 -L
device: UFS

Before -
read throughput: 185 MB/s
total read requests: 85177 (of these ~80000 are 4KB size requests).
total write requests: 2546 (of these ~2208 requests are written in 512KB).

After -
read throughput: 758 MB/s
total read requests: 2417 (of these ~2042 are 512KB reads).
total write requests: 2701 (of these ~2034 requests are written in 512KB).
Signed-off-by: NSahitya Tummala <stummala@codeaurora.org>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

a_ops->readpages() is only ever used for read-ahead, yet we don't flag
the IO being submitted as such.  Fix that up.  Any file system that uses
mpage_readpages() as its ->readpages() implementation will now get this
right.

Since we're passing in whether the IO is read-ahead or not, we don't
need to pass in the 'gfp' separately, as it is dependent on the IO being
read-ahead.  Kill off that member.

Add some documentation notes on ->readpages() being purely for
read-ahead.

Link: http://lkml.kernel.org/r/20180621010725.17813-3-axboe@kernel.dkSigned-off-by: NJens Axboe <axboe@kernel.dk>
Reviewed-by: NAndrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Chris Mason <clm@fb.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When CONFIG_F2FS_FAULT_INJECTION is disabled, we get a warning about an
unused label:

fs/f2fs/segment.c: In function '__submit_discard_cmd':
fs/f2fs/segment.c:1059:1: error: label 'submit' defined but not used [-Werror=unused-label]

This could be fixed by adding another #ifdef around it, but the more
reliable way of doing this seems to be to remove the other #ifdefs
where that is easily possible.

By defining time_to_inject() as a trivial stub, most of the checks for
CONFIG_F2FS_FAULT_INJECTION can go away. This also leads to nicer
formatting of the code.
Signed-off-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Thread A				Background GC
- f2fs_setattr isize to 0
 - truncate_setsize
					- gc_data_segment
					 - f2fs_get_read_data_page page #0
					  - set_page_dirty
					  - set_cold_data
 - f2fs_truncate

- f2fs_setattr isize to 4k
- read 4k <--- hit data in cached page #0

Above race condition can cause read out invalid data in a truncated
page, fix it by i_gc_rwsem[WRITE] lock.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch adds f2fs_is_valid_blkaddr() in below functions to do sanity
check with block address to avoid pentential panic:
- f2fs_grab_read_bio()
- __written_first_block()

https://bugzilla.kernel.org/show_bug.cgi?id=200465

- Reproduce

- POC (poc.c)
    #define _GNU_SOURCE
    #include <sys/types.h>
    #include <sys/mount.h>
    #include <sys/mman.h>
    #include <sys/stat.h>
    #include <sys/xattr.h>

    #include <dirent.h>
    #include <errno.h>
    #include <error.h>
    #include <fcntl.h>
    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <unistd.h>

    #include <linux/falloc.h>
    #include <linux/loop.h>

    static void activity(char *mpoint) {

      char *xattr;
      int err;

      err = asprintf(&xattr, "%s/foo/bar/xattr", mpoint);

      char buf2[113];
      memset(buf2, 0, sizeof(buf2));
      listxattr(xattr, buf2, sizeof(buf2));

    }

    int main(int argc, char *argv[]) {
      activity(argv[1]);
      return 0;
    }

- kernel message
[  844.718738] F2FS-fs (loop0): Mounted with checkpoint version = 2
[  846.430929] F2FS-fs (loop0): access invalid blkaddr:1024
[  846.431058] WARNING: CPU: 1 PID: 1249 at fs/f2fs/checkpoint.c:154 f2fs_is_valid_blkaddr+0x10f/0x160
[  846.431059] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd input_leds joydev soundcore serio_raw i2c_piix4 mac_hid ib_iser rdma_cm iw_cm ib_cm ib_core configfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 raid10 raid456 libcrc32c async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq raid1 raid0 multipath linear qxl ttm crct10dif_pclmul crc32_pclmul drm_kms_helper ghash_clmulni_intel syscopyarea sysfillrect sysimgblt fb_sys_fops pcbc drm 8139too aesni_intel 8139cp floppy psmouse mii aes_x86_64 crypto_simd pata_acpi cryptd glue_helper
[  846.431310] CPU: 1 PID: 1249 Comm: a.out Not tainted 4.18.0-rc3+ #1
[  846.431312] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  846.431315] RIP: 0010:f2fs_is_valid_blkaddr+0x10f/0x160
[  846.431316] Code: 00 eb ed 31 c0 83 fa 05 75 ae 48 83 ec 08 48 8b 3f 89 f1 48 c7 c2 fc 0b 0f 8b 48 c7 c6 8b d7 09 8b 88 44 24 07 e8 61 8b ff ff <0f> 0b 0f b6 44 24 07 48 83 c4 08 eb 81 4c 8b 47 10 8b 8f 38 04 00
[  846.431347] RSP: 0018:ffff961c414a7bc0 EFLAGS: 00010282
[  846.431349] RAX: 0000000000000000 RBX: ffffc5f787b8ea80 RCX: 0000000000000000
[  846.431350] RDX: 0000000000000000 RSI: ffff89dfffd165d8 RDI: ffff89dfffd165d8
[  846.431351] RBP: ffff961c414a7c20 R08: 0000000000000001 R09: 0000000000000248
[  846.431353] R10: 0000000000000000 R11: 0000000000000248 R12: 0000000000000007
[  846.431369] R13: ffff89dff5492800 R14: ffff89dfae3aa000 R15: ffff89dff4ff88d0
[  846.431372] FS:  00007f882e2fb700(0000) GS:ffff89dfffd00000(0000) knlGS:0000000000000000
[  846.431373] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  846.431374] CR2: 0000000001a88008 CR3: 00000001eb572000 CR4: 00000000000006e0
[  846.431384] Call Trace:
[  846.431426]  f2fs_iget+0x6f4/0xe70
[  846.431430]  ? f2fs_find_entry+0x71/0x90
[  846.431432]  f2fs_lookup+0x1aa/0x390
[  846.431452]  __lookup_slow+0x97/0x150
[  846.431459]  lookup_slow+0x35/0x50
[  846.431462]  walk_component+0x1c6/0x470
[  846.431479]  ? memcg_kmem_charge_memcg+0x70/0x90
[  846.431488]  ? page_add_file_rmap+0x13/0x200
[  846.431491]  path_lookupat+0x76/0x230
[  846.431501]  ? __alloc_pages_nodemask+0xfc/0x280
[  846.431504]  filename_lookup+0xb8/0x1a0
[  846.431534]  ? _cond_resched+0x16/0x40
[  846.431541]  ? kmem_cache_alloc+0x160/0x1d0
[  846.431549]  ? path_listxattr+0x41/0xa0
[  846.431551]  path_listxattr+0x41/0xa0
[  846.431570]  do_syscall_64+0x55/0x100
[  846.431583]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  846.431607] RIP: 0033:0x7f882de1c0d7
[  846.431607] Code: f0 ff ff 73 01 c3 48 8b 0d be dd 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 c2 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 dd 2b 00 f7 d8 64 89 01 48
[  846.431639] RSP: 002b:00007ffe8e66c238 EFLAGS: 00000202 ORIG_RAX: 00000000000000c2
[  846.431641] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f882de1c0d7
[  846.431642] RDX: 0000000000000071 RSI: 00007ffe8e66c280 RDI: 0000000001a880c0
[  846.431643] RBP: 00007ffe8e66c300 R08: 0000000001a88010 R09: 0000000000000000
[  846.431645] R10: 00000000000001ab R11: 0000000000000202 R12: 0000000000400550
[  846.431646] R13: 00007ffe8e66c400 R14: 0000000000000000 R15: 0000000000000000
[  846.431648] ---[ end trace abca54df39d14f5c ]---
[  846.431651] F2FS-fs (loop0): invalid blkaddr: 1024, type: 5, run fsck to fix.
[  846.431762] WARNING: CPU: 1 PID: 1249 at fs/f2fs/f2fs.h:2697 f2fs_iget+0xd17/0xe70
[  846.431763] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd input_leds joydev soundcore serio_raw i2c_piix4 mac_hid ib_iser rdma_cm iw_cm ib_cm ib_core configfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 raid10 raid456 libcrc32c async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq raid1 raid0 multipath linear qxl ttm crct10dif_pclmul crc32_pclmul drm_kms_helper ghash_clmulni_intel syscopyarea sysfillrect sysimgblt fb_sys_fops pcbc drm 8139too aesni_intel 8139cp floppy psmouse mii aes_x86_64 crypto_simd pata_acpi cryptd glue_helper
[  846.431797] CPU: 1 PID: 1249 Comm: a.out Tainted: G        W         4.18.0-rc3+ #1
[  846.431798] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  846.431800] RIP: 0010:f2fs_iget+0xd17/0xe70
[  846.431801] Code: ff ff 48 63 d8 e9 e1 f6 ff ff 48 8b 45 c8 41 b8 05 00 00 00 48 c7 c2 d8 e8 0e 8b 48 c7 c6 1d b0 0a 8b 48 8b 38 e8 f9 b4 00 00 <0f> 0b 48 8b 45 c8 f0 80 48 48 04 e9 d8 f9 ff ff 0f 0b 48 8b 43 18
[  846.431832] RSP: 0018:ffff961c414a7bd0 EFLAGS: 00010282
[  846.431834] RAX: 0000000000000000 RBX: ffffc5f787b8ea80 RCX: 0000000000000006
[  846.431835] RDX: 0000000000000000 RSI: 0000000000000096 RDI: ffff89dfffd165d0
[  846.431836] RBP: ffff961c414a7c20 R08: 0000000000000000 R09: 0000000000000273
[  846.431837] R10: 0000000000000000 R11: ffff89dfad50ca60 R12: 0000000000000007
[  846.431838] R13: ffff89dff5492800 R14: ffff89dfae3aa000 R15: ffff89dff4ff88d0
[  846.431840] FS:  00007f882e2fb700(0000) GS:ffff89dfffd00000(0000) knlGS:0000000000000000
[  846.431841] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  846.431842] CR2: 0000000001a88008 CR3: 00000001eb572000 CR4: 00000000000006e0
[  846.431846] Call Trace:
[  846.431850]  ? f2fs_find_entry+0x71/0x90
[  846.431853]  f2fs_lookup+0x1aa/0x390
[  846.431856]  __lookup_slow+0x97/0x150
[  846.431858]  lookup_slow+0x35/0x50
[  846.431874]  walk_component+0x1c6/0x470
[  846.431878]  ? memcg_kmem_charge_memcg+0x70/0x90
[  846.431880]  ? page_add_file_rmap+0x13/0x200
[  846.431882]  path_lookupat+0x76/0x230
[  846.431884]  ? __alloc_pages_nodemask+0xfc/0x280
[  846.431886]  filename_lookup+0xb8/0x1a0
[  846.431890]  ? _cond_resched+0x16/0x40
[  846.431891]  ? kmem_cache_alloc+0x160/0x1d0
[  846.431894]  ? path_listxattr+0x41/0xa0
[  846.431896]  path_listxattr+0x41/0xa0
[  846.431898]  do_syscall_64+0x55/0x100
[  846.431901]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  846.431902] RIP: 0033:0x7f882de1c0d7
[  846.431903] Code: f0 ff ff 73 01 c3 48 8b 0d be dd 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 c2 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 dd 2b 00 f7 d8 64 89 01 48
[  846.431934] RSP: 002b:00007ffe8e66c238 EFLAGS: 00000202 ORIG_RAX: 00000000000000c2
[  846.431936] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f882de1c0d7
[  846.431937] RDX: 0000000000000071 RSI: 00007ffe8e66c280 RDI: 0000000001a880c0
[  846.431939] RBP: 00007ffe8e66c300 R08: 0000000001a88010 R09: 0000000000000000
[  846.431940] R10: 00000000000001ab R11: 0000000000000202 R12: 0000000000400550
[  846.431941] R13: 00007ffe8e66c400 R14: 0000000000000000 R15: 0000000000000000
[  846.431943] ---[ end trace abca54df39d14f5d ]---
[  846.432033] F2FS-fs (loop0): access invalid blkaddr:1024
[  846.432051] WARNING: CPU: 1 PID: 1249 at fs/f2fs/checkpoint.c:154 f2fs_is_valid_blkaddr+0x10f/0x160
[  846.432051] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd input_leds joydev soundcore serio_raw i2c_piix4 mac_hid ib_iser rdma_cm iw_cm ib_cm ib_core configfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 raid10 raid456 libcrc32c async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq raid1 raid0 multipath linear qxl ttm crct10dif_pclmul crc32_pclmul drm_kms_helper ghash_clmulni_intel syscopyarea sysfillrect sysimgblt fb_sys_fops pcbc drm 8139too aesni_intel 8139cp floppy psmouse mii aes_x86_64 crypto_simd pata_acpi cryptd glue_helper
[  846.432085] CPU: 1 PID: 1249 Comm: a.out Tainted: G        W         4.18.0-rc3+ #1
[  846.432086] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  846.432089] RIP: 0010:f2fs_is_valid_blkaddr+0x10f/0x160
[  846.432089] Code: 00 eb ed 31 c0 83 fa 05 75 ae 48 83 ec 08 48 8b 3f 89 f1 48 c7 c2 fc 0b 0f 8b 48 c7 c6 8b d7 09 8b 88 44 24 07 e8 61 8b ff ff <0f> 0b 0f b6 44 24 07 48 83 c4 08 eb 81 4c 8b 47 10 8b 8f 38 04 00
[  846.432120] RSP: 0018:ffff961c414a7900 EFLAGS: 00010286
[  846.432122] RAX: 0000000000000000 RBX: 0000000000000400 RCX: 0000000000000006
[  846.432123] RDX: 0000000000000000 RSI: 0000000000000096 RDI: ffff89dfffd165d0
[  846.432124] RBP: ffff89dff5492800 R08: 0000000000000001 R09: 000000000000029d
[  846.432125] R10: ffff961c414a7820 R11: 000000000000029d R12: 0000000000000400
[  846.432126] R13: 0000000000000000 R14: ffff89dff4ff88d0 R15: 0000000000000000
[  846.432128] FS:  00007f882e2fb700(0000) GS:ffff89dfffd00000(0000) knlGS:0000000000000000
[  846.432130] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  846.432131] CR2: 0000000001a88008 CR3: 00000001eb572000 CR4: 00000000000006e0
[  846.432135] Call Trace:
[  846.432151]  f2fs_wait_on_block_writeback+0x20/0x110
[  846.432158]  f2fs_grab_read_bio+0xbc/0xe0
[  846.432161]  f2fs_submit_page_read+0x21/0x280
[  846.432163]  f2fs_get_read_data_page+0xb7/0x3c0
[  846.432165]  f2fs_get_lock_data_page+0x29/0x1e0
[  846.432167]  f2fs_get_new_data_page+0x148/0x550
[  846.432170]  f2fs_add_regular_entry+0x1d2/0x550
[  846.432178]  ? __switch_to+0x12f/0x460
[  846.432181]  f2fs_add_dentry+0x6a/0xd0
[  846.432184]  f2fs_do_add_link+0xe9/0x140
[  846.432186]  __recover_dot_dentries+0x260/0x280
[  846.432189]  f2fs_lookup+0x343/0x390
[  846.432193]  __lookup_slow+0x97/0x150
[  846.432195]  lookup_slow+0x35/0x50
[  846.432208]  walk_component+0x1c6/0x470
[  846.432212]  ? memcg_kmem_charge_memcg+0x70/0x90
[  846.432215]  ? page_add_file_rmap+0x13/0x200
[  846.432217]  path_lookupat+0x76/0x230
[  846.432219]  ? __alloc_pages_nodemask+0xfc/0x280
[  846.432221]  filename_lookup+0xb8/0x1a0
[  846.432224]  ? _cond_resched+0x16/0x40
[  846.432226]  ? kmem_cache_alloc+0x160/0x1d0
[  846.432228]  ? path_listxattr+0x41/0xa0
[  846.432230]  path_listxattr+0x41/0xa0
[  846.432233]  do_syscall_64+0x55/0x100
[  846.432235]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  846.432237] RIP: 0033:0x7f882de1c0d7
[  846.432237] Code: f0 ff ff 73 01 c3 48 8b 0d be dd 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 c2 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 dd 2b 00 f7 d8 64 89 01 48
[  846.432269] RSP: 002b:00007ffe8e66c238 EFLAGS: 00000202 ORIG_RAX: 00000000000000c2
[  846.432271] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f882de1c0d7
[  846.432272] RDX: 0000000000000071 RSI: 00007ffe8e66c280 RDI: 0000000001a880c0
[  846.432273] RBP: 00007ffe8e66c300 R08: 0000000001a88010 R09: 0000000000000000
[  846.432274] R10: 00000000000001ab R11: 0000000000000202 R12: 0000000000400550
[  846.432275] R13: 00007ffe8e66c400 R14: 0000000000000000 R15: 0000000000000000
[  846.432277] ---[ end trace abca54df39d14f5e ]---
[  846.432279] F2FS-fs (loop0): invalid blkaddr: 1024, type: 5, run fsck to fix.
[  846.432376] WARNING: CPU: 1 PID: 1249 at fs/f2fs/f2fs.h:2697 f2fs_wait_on_block_writeback+0xb1/0x110
[  846.432376] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd input_leds joydev soundcore serio_raw i2c_piix4 mac_hid ib_iser rdma_cm iw_cm ib_cm ib_core configfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 raid10 raid456 libcrc32c async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq raid1 raid0 multipath linear qxl ttm crct10dif_pclmul crc32_pclmul drm_kms_helper ghash_clmulni_intel syscopyarea sysfillrect sysimgblt fb_sys_fops pcbc drm 8139too aesni_intel 8139cp floppy psmouse mii aes_x86_64 crypto_simd pata_acpi cryptd glue_helper
[  846.432410] CPU: 1 PID: 1249 Comm: a.out Tainted: G        W         4.18.0-rc3+ #1
[  846.432411] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  846.432413] RIP: 0010:f2fs_wait_on_block_writeback+0xb1/0x110
[  846.432414] Code: 66 90 f0 ff 4b 34 74 59 5b 5d c3 48 8b 7d 00 41 b8 05 00 00 00 89 d9 48 c7 c2 d8 e8 0e 8b 48 c7 c6 1d b0 0a 8b e8 df bc fd ff <0f> 0b f0 80 4d 48 04 e9 67 ff ff ff 48 8b 03 48 c1 e8 37 83 e0 07
[  846.432445] RSP: 0018:ffff961c414a7910 EFLAGS: 00010286
[  846.432447] RAX: 0000000000000000 RBX: 0000000000000400 RCX: 0000000000000006
[  846.432448] RDX: 0000000000000000 RSI: 0000000000000092 RDI: ffff89dfffd165d0
[  846.432449] RBP: ffff89dff5492800 R08: 0000000000000000 R09: 00000000000002d1
[  846.432450] R10: ffff961c414a7820 R11: ffff89dfad50cf80 R12: 0000000000000400
[  846.432451] R13: 0000000000000000 R14: ffff89dff4ff88d0 R15: 0000000000000000
[  846.432453] FS:  00007f882e2fb700(0000) GS:ffff89dfffd00000(0000) knlGS:0000000000000000
[  846.432454] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  846.432455] CR2: 0000000001a88008 CR3: 00000001eb572000 CR4: 00000000000006e0
[  846.432459] Call Trace:
[  846.432463]  f2fs_grab_read_bio+0xbc/0xe0
[  846.432464]  f2fs_submit_page_read+0x21/0x280
[  846.432466]  f2fs_get_read_data_page+0xb7/0x3c0
[  846.432468]  f2fs_get_lock_data_page+0x29/0x1e0
[  846.432470]  f2fs_get_new_data_page+0x148/0x550
[  846.432473]  f2fs_add_regular_entry+0x1d2/0x550
[  846.432475]  ? __switch_to+0x12f/0x460
[  846.432477]  f2fs_add_dentry+0x6a/0xd0
[  846.432480]  f2fs_do_add_link+0xe9/0x140
[  846.432483]  __recover_dot_dentries+0x260/0x280
[  846.432485]  f2fs_lookup+0x343/0x390
[  846.432488]  __lookup_slow+0x97/0x150
[  846.432490]  lookup_slow+0x35/0x50
[  846.432505]  walk_component+0x1c6/0x470
[  846.432509]  ? memcg_kmem_charge_memcg+0x70/0x90
[  846.432511]  ? page_add_file_rmap+0x13/0x200
[  846.432513]  path_lookupat+0x76/0x230
[  846.432515]  ? __alloc_pages_nodemask+0xfc/0x280
[  846.432517]  filename_lookup+0xb8/0x1a0
[  846.432520]  ? _cond_resched+0x16/0x40
[  846.432522]  ? kmem_cache_alloc+0x160/0x1d0
[  846.432525]  ? path_listxattr+0x41/0xa0
[  846.432526]  path_listxattr+0x41/0xa0
[  846.432529]  do_syscall_64+0x55/0x100
[  846.432531]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  846.432533] RIP: 0033:0x7f882de1c0d7
[  846.432533] Code: f0 ff ff 73 01 c3 48 8b 0d be dd 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 c2 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 91 dd 2b 00 f7 d8 64 89 01 48
[  846.432565] RSP: 002b:00007ffe8e66c238 EFLAGS: 00000202 ORIG_RAX: 00000000000000c2
[  846.432567] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f882de1c0d7
[  846.432568] RDX: 0000000000000071 RSI: 00007ffe8e66c280 RDI: 0000000001a880c0
[  846.432569] RBP: 00007ffe8e66c300 R08: 0000000001a88010 R09: 0000000000000000
[  846.432570] R10: 00000000000001ab R11: 0000000000000202 R12: 0000000000400550
[  846.432571] R13: 00007ffe8e66c400 R14: 0000000000000000 R15: 0000000000000000
[  846.432573] ---[ end trace abca54df39d14f5f ]---
[  846.434280] BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
[  846.434424] PGD 80000001ebd3a067 P4D 80000001ebd3a067 PUD 1eb1ae067 PMD 0
[  846.434551] Oops: 0000 [#1] SMP PTI
[  846.434697] CPU: 0 PID: 44 Comm: kworker/u5:0 Tainted: G        W         4.18.0-rc3+ #1
[  846.434805] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  846.435000] Workqueue: fscrypt_read_queue decrypt_work
[  846.435174] RIP: 0010:fscrypt_do_page_crypto+0x6e/0x2d0
[  846.435351] Code: 00 65 48 8b 04 25 28 00 00 00 48 89 84 24 88 00 00 00 31 c0 e8 43 c2 e0 ff 49 8b 86 48 02 00 00 85 ed c7 44 24 70 00 00 00 00 <48> 8b 58 08 0f 84 14 02 00 00 48 8b 78 10 48 8b 0c 24 48 c7 84 24
[  846.435696] RSP: 0018:ffff961c40f9bd60 EFLAGS: 00010206
[  846.435870] RAX: 0000000000000000 RBX: ffffc5f787719b80 RCX: ffffc5f787719b80
[  846.436051] RDX: ffffffff8b9f4b88 RSI: ffffffff8b0ae622 RDI: ffff961c40f9bdb8
[  846.436261] RBP: 0000000000001000 R08: ffffc5f787719b80 R09: 0000000000001000
[  846.436433] R10: 0000000000000018 R11: fefefefefefefeff R12: ffffc5f787719b80
[  846.436562] R13: ffffc5f787719b80 R14: ffff89dff4ff88d0 R15: 0ffff89dfaddee60
[  846.436658] FS:  0000000000000000(0000) GS:ffff89dfffc00000(0000) knlGS:0000000000000000
[  846.436758] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  846.436898] CR2: 0000000000000008 CR3: 00000001eddd0000 CR4: 00000000000006f0
[  846.437001] Call Trace:
[  846.437181]  ? check_preempt_wakeup+0xf2/0x230
[  846.437276]  ? check_preempt_curr+0x7c/0x90
[  846.437370]  fscrypt_decrypt_page+0x48/0x4d
[  846.437466]  __fscrypt_decrypt_bio+0x5b/0x90
[  846.437542]  decrypt_work+0x12/0x20
[  846.437651]  process_one_work+0x15e/0x3d0
[  846.437740]  worker_thread+0x4c/0x440
[  846.437848]  kthread+0xf8/0x130
[  846.437938]  ? rescuer_thread+0x350/0x350
[  846.438022]  ? kthread_associate_blkcg+0x90/0x90
[  846.438117]  ret_from_fork+0x35/0x40
[  846.438201] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep snd_pcm snd_timer snd input_leds joydev soundcore serio_raw i2c_piix4 mac_hid ib_iser rdma_cm iw_cm ib_cm ib_core configfs iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi autofs4 raid10 raid456 libcrc32c async_raid6_recov async_memcpy async_pq async_xor xor async_tx raid6_pq raid1 raid0 multipath linear qxl ttm crct10dif_pclmul crc32_pclmul drm_kms_helper ghash_clmulni_intel syscopyarea sysfillrect sysimgblt fb_sys_fops pcbc drm 8139too aesni_intel 8139cp floppy psmouse mii aes_x86_64 crypto_simd pata_acpi cryptd glue_helper
[  846.438653] CR2: 0000000000000008
[  846.438713] ---[ end trace abca54df39d14f60 ]---
[  846.438796] RIP: 0010:fscrypt_do_page_crypto+0x6e/0x2d0
[  846.438844] Code: 00 65 48 8b 04 25 28 00 00 00 48 89 84 24 88 00 00 00 31 c0 e8 43 c2 e0 ff 49 8b 86 48 02 00 00 85 ed c7 44 24 70 00 00 00 00 <48> 8b 58 08 0f 84 14 02 00 00 48 8b 78 10 48 8b 0c 24 48 c7 84 24
[  846.439084] RSP: 0018:ffff961c40f9bd60 EFLAGS: 00010206
[  846.439176] RAX: 0000000000000000 RBX: ffffc5f787719b80 RCX: ffffc5f787719b80
[  846.440927] RDX: ffffffff8b9f4b88 RSI: ffffffff8b0ae622 RDI: ffff961c40f9bdb8
[  846.442083] RBP: 0000000000001000 R08: ffffc5f787719b80 R09: 0000000000001000
[  846.443284] R10: 0000000000000018 R11: fefefefefefefeff R12: ffffc5f787719b80
[  846.444448] R13: ffffc5f787719b80 R14: ffff89dff4ff88d0 R15: 0ffff89dfaddee60
[  846.445558] FS:  0000000000000000(0000) GS:ffff89dfffc00000(0000) knlGS:0000000000000000
[  846.446687] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  846.447796] CR2: 0000000000000008 CR3: 00000001eddd0000 CR4: 00000000000006f0

- Location
https://elixir.bootlin.com/linux/v4.18-rc4/source/fs/crypto/crypto.c#L149
	struct crypto_skcipher *tfm = ci->ci_ctfm;
Here ci can be NULL

Note that this issue maybe require CONFIG_F2FS_FS_ENCRYPTION=y to reproduce.

Reported-by Wen Xu <wen.xu@gatech.edu>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs recovery flow is relying on dnode block link list, it means fsynced
file recovery depends on previous dnode's persistence in the list, so
during fsync() we should wait on all regular inode's dnode writebacked
before issuing flush.

By this way, we can avoid dnode block list being broken by out-of-order
IO submission due to IO scheduler or driver.

Sheng Yong helps to do the test with this patch:

Target:/data (f2fs, -)
64MB / 32768KB / 4KB / 8

1 / PERSIST / Index

Base:
	SEQ-RD(MB/s)	SEQ-WR(MB/s)	RND-RD(IOPS)	RND-WR(IOPS)	Insert(TPS)	Update(TPS)	Delete(TPS)
1	867.82		204.15		41440.03	41370.54	680.8		1025.94		1031.08
2	871.87		205.87		41370.3		40275.2		791.14		1065.84		1101.7
3	866.52		205.69		41795.67	40596.16	694.69		1037.16		1031.48
Avg	868.7366667	205.2366667	41535.33333	40747.3		722.21		1042.98		1054.753333

After:
	SEQ-RD(MB/s)	SEQ-WR(MB/s)	RND-RD(IOPS)	RND-WR(IOPS)	Insert(TPS)	Update(TPS)	Delete(TPS)
1	798.81		202.5		41143		40613.87	602.71		838.08		913.83
2	805.79		206.47		40297.2		41291.46	604.44		840.75		924.27
3	814.83		206.17		41209.57	40453.62	602.85		834.66		927.91
Avg	806.4766667	205.0466667	40883.25667	40786.31667	603.3333333	837.83		922.0033333

Patched/Original:
	0.928332713	0.999074239	0.984300676	1.000957528	0.835398753	0.803303994	0.874141189

It looks like atomic write will suffer performance regression.

I suspect that the criminal is that we forcing to wait all dnode being in
storage cache before we issue PREFLUSH+FUA.

BTW, will commit ("f2fs: don't need to wait for node writes for atomic write")
cause the problem: we will lose data of last transaction after SPO, even if
atomic write return no error:

- atomic_open();
- write() P1, P2, P3;
- atomic_commit();
 - writeback data: P1, P2, P3;
 - writeback node: N1, N2, N3;  <--- If N1, N2 is not writebacked, N3 with fsync_mark is
writebacked, In SPOR, we won't find N3 since node chain is broken, turns out that losing
last transaction.
 - preflush + fua;
- power-cut

If we don't wait dnode writeback for atomic_write:

	SEQ-RD(MB/s)	SEQ-WR(MB/s)	RND-RD(IOPS)	RND-WR(IOPS)	Insert(TPS)	Update(TPS)	Delete(TPS)
1	779.91		206.03		41621.5		40333.16	716.9		1038.21		1034.85
2	848.51		204.35		40082.44	39486.17	791.83		1119.96		1083.77
3	772.12		206.27		41335.25	41599.65	723.29		1055.07		971.92
Avg	800.18		205.55		41013.06333	40472.99333	744.0066667	1071.08		1030.18

Patched/Original:
	0.92108464	1.001526693	0.987425886	0.993268102	1.030180511	1.026942031	0.976702294

SQLite's performance recovers.

Jaegeuk:
"Practically, I don't see db corruption becase of this. We can excuse to lose
the last transaction."

Finally, we decide to keep original implementation of atomic write interface
sematics that we don't wait all dnode writeback before preflush+fua submission.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

PG_checked flag will be set on data page during GC, later, we can
recognize such page by the flag and migrate page to cold segment.

But previously, we don't clear this flag when invalidating data page,
after page redirtying, we will write it into wrong log.

Let's clear PG_checked flag in set_page_dirty() to avoid this.
Signed-off-by: NWeichao Guo <guoweichao@huawei.com>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

In order to prevent abusing atomic writes by abnormal users, we've added a
threshold, 20% over memory footprint, which disallows further atomic writes.
Previously, however, SQLite doesn't know the files became normal, so that
it could write stale data and commit on revoked normal database file.

Once f2fs detects such the abnormal behavior, this patch tries to avoid further
writes in write_begin().
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

If caller of __get_meta_page() can handle error, let's propagate error
from __get_meta_page().
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Expand the blk_finish_plug action from blkzoned to normal lfs mode,
since plug will cause the out-of-order IO submission, which is not
friendly to flash in lfs mode.
Signed-off-by: NYunlong Song <yunlong.song@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch add to do sanity check with below field:
- cp_pack_total_block_count
- blkaddr of data/node
- extent info

- Overview
BUG() in verify_block_addr() when writing to a corrupted f2fs image

- Reproduce (4.18 upstream kernel)

- POC (poc.c)

static void activity(char *mpoint) {

  char *foo_bar_baz;
  int err;

  static int buf[8192];
  memset(buf, 0, sizeof(buf));

  err = asprintf(&foo_bar_baz, "%s/foo/bar/baz", mpoint);

  int fd = open(foo_bar_baz, O_RDWR | O_TRUNC, 0777);
  if (fd >= 0) {
    write(fd, (char *)buf, sizeof(buf));
    fdatasync(fd);
    close(fd);
  }
}

int main(int argc, char *argv[]) {
  activity(argv[1]);
  return 0;
}

- Kernel message
[  689.349473] F2FS-fs (loop0): Mounted with checkpoint version = 3
[  699.728662] WARNING: CPU: 0 PID: 1309 at fs/f2fs/segment.c:2860 f2fs_inplace_write_data+0x232/0x240
[  699.728670] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy
[  699.729056] CPU: 0 PID: 1309 Comm: a.out Not tainted 4.18.0-rc1+ #4
[  699.729064] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  699.729074] RIP: 0010:f2fs_inplace_write_data+0x232/0x240
[  699.729076] Code: ff e9 cf fe ff ff 49 8d 7d 10 e8 39 45 ad ff 4d 8b 7d 10 be 04 00 00 00 49 8d 7f 48 e8 07 49 ad ff 45 8b 7f 48 e9 fb fe ff ff <0f> 0b f0 41 80 4d 48 04 e9 65 fe ff ff 90 66 66 66 66 90 55 48 8d
[  699.729130] RSP: 0018:ffff8801f43af568 EFLAGS: 00010202
[  699.729139] RAX: 000000000000003f RBX: ffff8801f43af7b8 RCX: ffffffffb88c9113
[  699.729142] RDX: 0000000000000003 RSI: dffffc0000000000 RDI: ffff8802024e5540
[  699.729144] RBP: ffff8801f43af590 R08: 0000000000000009 R09: ffffffffffffffe8
[  699.729147] R10: 0000000000000001 R11: ffffed0039b0596a R12: ffff8802024e5540
[  699.729149] R13: ffff8801f0335500 R14: ffff8801e3e7a700 R15: ffff8801e1ee4450
[  699.729154] FS:  00007f9bf97f5700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000
[  699.729156] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  699.729159] CR2: 00007f9bf925d170 CR3: 00000001f0c34000 CR4: 00000000000006f0
[  699.729171] Call Trace:
[  699.729192]  f2fs_do_write_data_page+0x2e2/0xe00
[  699.729203]  ? f2fs_should_update_outplace+0xd0/0xd0
[  699.729238]  ? memcg_drain_all_list_lrus+0x280/0x280
[  699.729269]  ? __radix_tree_replace+0xa3/0x120
[  699.729276]  __write_data_page+0x5c7/0xe30
[  699.729291]  ? kasan_check_read+0x11/0x20
[  699.729310]  ? page_mapped+0x8a/0x110
[  699.729321]  ? page_mkclean+0xe9/0x160
[  699.729327]  ? f2fs_do_write_data_page+0xe00/0xe00
[  699.729331]  ? invalid_page_referenced_vma+0x130/0x130
[  699.729345]  ? clear_page_dirty_for_io+0x332/0x450
[  699.729351]  f2fs_write_cache_pages+0x4ca/0x860
[  699.729358]  ? __write_data_page+0xe30/0xe30
[  699.729374]  ? percpu_counter_add_batch+0x22/0xa0
[  699.729380]  ? kasan_check_write+0x14/0x20
[  699.729391]  ? _raw_spin_lock+0x17/0x40
[  699.729403]  ? f2fs_mark_inode_dirty_sync.part.18+0x16/0x30
[  699.729413]  ? iov_iter_advance+0x113/0x640
[  699.729418]  ? f2fs_write_end+0x133/0x2e0
[  699.729423]  ? balance_dirty_pages_ratelimited+0x239/0x640
[  699.729428]  f2fs_write_data_pages+0x329/0x520
[  699.729433]  ? generic_perform_write+0x250/0x320
[  699.729438]  ? f2fs_write_cache_pages+0x860/0x860
[  699.729454]  ? current_time+0x110/0x110
[  699.729459]  ? f2fs_preallocate_blocks+0x1ef/0x370
[  699.729464]  do_writepages+0x37/0xb0
[  699.729468]  ? f2fs_write_cache_pages+0x860/0x860
[  699.729472]  ? do_writepages+0x37/0xb0
[  699.729478]  __filemap_fdatawrite_range+0x19a/0x1f0
[  699.729483]  ? delete_from_page_cache_batch+0x4e0/0x4e0
[  699.729496]  ? __vfs_write+0x2b2/0x410
[  699.729501]  file_write_and_wait_range+0x66/0xb0
[  699.729506]  f2fs_do_sync_file+0x1f9/0xd90
[  699.729511]  ? truncate_partial_data_page+0x290/0x290
[  699.729521]  ? __sb_end_write+0x30/0x50
[  699.729526]  ? vfs_write+0x20f/0x260
[  699.729530]  f2fs_sync_file+0x9a/0xb0
[  699.729534]  ? f2fs_do_sync_file+0xd90/0xd90
[  699.729548]  vfs_fsync_range+0x68/0x100
[  699.729554]  ? __fget_light+0xc9/0xe0
[  699.729558]  do_fsync+0x3d/0x70
[  699.729562]  __x64_sys_fdatasync+0x24/0x30
[  699.729585]  do_syscall_64+0x78/0x170
[  699.729595]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  699.729613] RIP: 0033:0x7f9bf930d800
[  699.729615] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 49 bf 2c 00 00 75 10 b8 4b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 be 78 01 00 48 89 04 24
[  699.729668] RSP: 002b:00007ffee3606c68 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
[  699.729673] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9bf930d800
[  699.729675] RDX: 0000000000008000 RSI: 00000000006010a0 RDI: 0000000000000003
[  699.729678] RBP: 00007ffee3606ca0 R08: 0000000001503010 R09: 0000000000000000
[  699.729680] R10: 00000000000002e8 R11: 0000000000000246 R12: 0000000000400610
[  699.729683] R13: 00007ffee3606da0 R14: 0000000000000000 R15: 0000000000000000
[  699.729687] ---[ end trace 4ce02f25ff7d3df5 ]---
[  699.729782] ------------[ cut here ]------------
[  699.729785] kernel BUG at fs/f2fs/segment.h:654!
[  699.731055] invalid opcode: 0000 [#1] SMP KASAN PTI
[  699.732104] CPU: 0 PID: 1309 Comm: a.out Tainted: G        W         4.18.0-rc1+ #4
[  699.733684] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  699.735611] RIP: 0010:f2fs_submit_page_bio+0x29b/0x730
[  699.736649] Code: 54 49 8d bd 18 04 00 00 e8 b2 59 af ff 41 8b 8d 18 04 00 00 8b 45 b8 41 d3 e6 44 01 f0 4c 8d 73 14 41 39 c7 0f 82 37 fe ff ff <0f> 0b 65 8b 05 2c 04 77 47 89 c0 48 0f a3 05 52 c1 d5 01 0f 92 c0
[  699.740524] RSP: 0018:ffff8801f43af508 EFLAGS: 00010283
[  699.741573] RAX: 0000000000000000 RBX: ffff8801f43af7b8 RCX: ffffffffb88a7cef
[  699.743006] RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff8801e3e7a64c
[  699.744426] RBP: ffff8801f43af558 R08: ffffed003e066b55 R09: ffffed003e066b55
[  699.745833] R10: 0000000000000001 R11: ffffed003e066b54 R12: ffffea0007876940
[  699.747256] R13: ffff8801f0335500 R14: ffff8801e3e7a600 R15: 0000000000000001
[  699.748683] FS:  00007f9bf97f5700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000
[  699.750293] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  699.751462] CR2: 00007f9bf925d170 CR3: 00000001f0c34000 CR4: 00000000000006f0
[  699.752874] Call Trace:
[  699.753386]  ? f2fs_inplace_write_data+0x93/0x240
[  699.754341]  f2fs_inplace_write_data+0xd2/0x240
[  699.755271]  f2fs_do_write_data_page+0x2e2/0xe00
[  699.756214]  ? f2fs_should_update_outplace+0xd0/0xd0
[  699.757215]  ? memcg_drain_all_list_lrus+0x280/0x280
[  699.758209]  ? __radix_tree_replace+0xa3/0x120
[  699.759164]  __write_data_page+0x5c7/0xe30
[  699.760002]  ? kasan_check_read+0x11/0x20
[  699.760823]  ? page_mapped+0x8a/0x110
[  699.761573]  ? page_mkclean+0xe9/0x160
[  699.762345]  ? f2fs_do_write_data_page+0xe00/0xe00
[  699.763332]  ? invalid_page_referenced_vma+0x130/0x130
[  699.764374]  ? clear_page_dirty_for_io+0x332/0x450
[  699.765347]  f2fs_write_cache_pages+0x4ca/0x860
[  699.766276]  ? __write_data_page+0xe30/0xe30
[  699.767161]  ? percpu_counter_add_batch+0x22/0xa0
[  699.768112]  ? kasan_check_write+0x14/0x20
[  699.768951]  ? _raw_spin_lock+0x17/0x40
[  699.769739]  ? f2fs_mark_inode_dirty_sync.part.18+0x16/0x30
[  699.770885]  ? iov_iter_advance+0x113/0x640
[  699.771743]  ? f2fs_write_end+0x133/0x2e0
[  699.772569]  ? balance_dirty_pages_ratelimited+0x239/0x640
[  699.773680]  f2fs_write_data_pages+0x329/0x520
[  699.774603]  ? generic_perform_write+0x250/0x320
[  699.775544]  ? f2fs_write_cache_pages+0x860/0x860
[  699.776510]  ? current_time+0x110/0x110
[  699.777299]  ? f2fs_preallocate_blocks+0x1ef/0x370
[  699.778279]  do_writepages+0x37/0xb0
[  699.779026]  ? f2fs_write_cache_pages+0x860/0x860
[  699.779978]  ? do_writepages+0x37/0xb0
[  699.780755]  __filemap_fdatawrite_range+0x19a/0x1f0
[  699.781746]  ? delete_from_page_cache_batch+0x4e0/0x4e0
[  699.782820]  ? __vfs_write+0x2b2/0x410
[  699.783597]  file_write_and_wait_range+0x66/0xb0
[  699.784540]  f2fs_do_sync_file+0x1f9/0xd90
[  699.785381]  ? truncate_partial_data_page+0x290/0x290
[  699.786415]  ? __sb_end_write+0x30/0x50
[  699.787204]  ? vfs_write+0x20f/0x260
[  699.787941]  f2fs_sync_file+0x9a/0xb0
[  699.788694]  ? f2fs_do_sync_file+0xd90/0xd90
[  699.789572]  vfs_fsync_range+0x68/0x100
[  699.790360]  ? __fget_light+0xc9/0xe0
[  699.791128]  do_fsync+0x3d/0x70
[  699.791779]  __x64_sys_fdatasync+0x24/0x30
[  699.792614]  do_syscall_64+0x78/0x170
[  699.793371]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[  699.794406] RIP: 0033:0x7f9bf930d800
[  699.795134] Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 83 3d 49 bf 2c 00 00 75 10 b8 4b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 be 78 01 00 48 89 04 24
[  699.798960] RSP: 002b:00007ffee3606c68 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
[  699.800483] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9bf930d800
[  699.801923] RDX: 0000000000008000 RSI: 00000000006010a0 RDI: 0000000000000003
[  699.803373] RBP: 00007ffee3606ca0 R08: 0000000001503010 R09: 0000000000000000
[  699.804798] R10: 00000000000002e8 R11: 0000000000000246 R12: 0000000000400610
[  699.806233] R13: 00007ffee3606da0 R14: 0000000000000000 R15: 0000000000000000
[  699.807667] Modules linked in: snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_pcm snd_timer snd mac_hid i2c_piix4 soundcore ib_iser rdma_cm iw_cm ib_cm ib_core iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx raid1 raid0 multipath linear 8139too crct10dif_pclmul crc32_pclmul qxl drm_kms_helper syscopyarea aesni_intel sysfillrect sysimgblt fb_sys_fops ttm drm aes_x86_64 crypto_simd cryptd 8139cp glue_helper mii pata_acpi floppy
[  699.817079] ---[ end trace 4ce02f25ff7d3df6 ]---
[  699.818068] RIP: 0010:f2fs_submit_page_bio+0x29b/0x730
[  699.819114] Code: 54 49 8d bd 18 04 00 00 e8 b2 59 af ff 41 8b 8d 18 04 00 00 8b 45 b8 41 d3 e6 44 01 f0 4c 8d 73 14 41 39 c7 0f 82 37 fe ff ff <0f> 0b 65 8b 05 2c 04 77 47 89 c0 48 0f a3 05 52 c1 d5 01 0f 92 c0
[  699.822919] RSP: 0018:ffff8801f43af508 EFLAGS: 00010283
[  699.823977] RAX: 0000000000000000 RBX: ffff8801f43af7b8 RCX: ffffffffb88a7cef
[  699.825436] RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff8801e3e7a64c
[  699.826881] RBP: ffff8801f43af558 R08: ffffed003e066b55 R09: ffffed003e066b55
[  699.828292] R10: 0000000000000001 R11: ffffed003e066b54 R12: ffffea0007876940
[  699.829750] R13: ffff8801f0335500 R14: ffff8801e3e7a600 R15: 0000000000000001
[  699.831192] FS:  00007f9bf97f5700(0000) GS:ffff8801f6e00000(0000) knlGS:0000000000000000
[  699.832793] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  699.833981] CR2: 00007f9bf925d170 CR3: 00000001f0c34000 CR4: 00000000000006f0
[  699.835556] ==================================================================
[  699.837029] BUG: KASAN: stack-out-of-bounds in update_stack_state+0x38c/0x3e0
[  699.838462] Read of size 8 at addr ffff8801f43af970 by task a.out/1309

[  699.840086] CPU: 0 PID: 1309 Comm: a.out Tainted: G      D W         4.18.0-rc1+ #4
[  699.841603] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014
[  699.843475] Call Trace:
[  699.843982]  dump_stack+0x7b/0xb5
[  699.844661]  print_address_description+0x70/0x290
[  699.845607]  kasan_report+0x291/0x390
[  699.846351]  ? update_stack_state+0x38c/0x3e0
[  699.853831]  __asan_load8+0x54/0x90
[  699.854569]  update_stack_state+0x38c/0x3e0
[  699.855428]  ? __read_once_size_nocheck.constprop.7+0x20/0x20
[  699.856601]  ? __save_stack_trace+0x5e/0x100
[  699.857476]  unwind_next_frame.part.5+0x18e/0x490
[  699.858448]  ? unwind_dump+0x290/0x290
[  699.859217]  ? clear_page_dirty_for_io+0x332/0x450
[  699.860185]  __unwind_start+0x106/0x190
[  699.860974]  __save_stack_trace+0x5e/0x100
[  699.861808]  ? __save_stack_trace+0x5e/0x100
[  699.862691]  ? unlink_anon_vmas+0xba/0x2c0
[  699.863525]  save_stack_trace+0x1f/0x30
[  699.864312]  save_stack+0x46/0xd0
[  699.864993]  ? __alloc_pages_slowpath+0x1420/0x1420
[  699.865990]  ? flush_tlb_mm_range+0x15e/0x220
[  699.866889]  ? kasan_check_write+0x14/0x20
[  699.867724]  ? __dec_node_state+0x92/0xb0
[  699.868543]  ? lock_page_memcg+0x85/0xf0
[  699.869350]  ? unlock_page_memcg+0x16/0x80
[  699.870185]  ? page_remove_rmap+0x198/0x520
[  699.871048]  ? mark_page_accessed+0x133/0x200
[  699.871930]  ? _cond_resched+0x1a/0x50
[  699.872700]  ? unmap_page_range+0xcd4/0xe50
[  699.873551]  ? rb_next+0x58/0x80
[  699.874217]  ? rb_next+0x58/0x80
[  699.874895]  __kasan_slab_free+0x13c/0x1a0
[  699.875734]  ? unlink_anon_vmas+0xba/0x2c0
[  699.876563]  kasan_slab_free+0xe/0x10
[  699.877315]  kmem_cache_free+0x89/0x1e0
[  699.878095]  unlink_anon_vmas+0xba/0x2c0
[  699.878913]  free_pgtables+0x101/0x1b0
[  699.879677]  exit_mmap+0x146/0x2a0
[  699.880378]  ? __ia32_sys_munmap+0x50/0x50
[  699.881214]  ? kasan_check_read+0x11/0x20
[  699.882052]  ? mm_update_next_owner+0x322/0x380
[  699.882985]  mmput+0x8b/0x1d0
[  699.883602]  do_exit+0x43a/0x1390
[  699.884288]  ? mm_update_next_owner+0x380/0x380
[  699.885212]  ? f2fs_sync_file+0x9a/0xb0
[  699.885995]  ? f2fs_do_sync_file+0xd90/0xd90
[  699.886877]  ? vfs_fsync_range+0x68/0x100
[  699.887694]  ? __fget_light+0xc9/0xe0
[  699.888442]  ? do_fsync+0x3d/0x70
[  699.889118]  ? __x64_sys_fdatasync+0x24/0x30
[  699.889996]  rewind_stack_do_exit+0x17/0x20
[  699.890860] RIP: 0033:0x7f9bf930d800
[  699.891585] Code: Bad RIP value.
[  699.892268] RSP: 002b:00007ffee3606c68 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
[  699.893781] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9bf930d800
[  699.895220] RDX: 0000000000008000 RSI: 00000000006010a0 RDI: 0000000000000003
[  699.896643] RBP: 00007ffee3606ca0 R08: 0000000001503010 R09: 0000000000000000
[  699.898069] R10: 00000000000002e8 R11: 0000000000000246 R12: 0000000000400610
[  699.899505] R13: 00007ffee3606da0 R14: 0000000000000000 R15: 0000000000000000

[  699.901241] The buggy address belongs to the page:
[  699.902215] page:ffffea0007d0ebc0 count:0 mapcount:0 mapping:0000000000000000 index:0x0
[  699.903811] flags: 0x2ffff0000000000()
[  699.904585] raw: 02ffff0000000000 0000000000000000 ffffffff07d00101 0000000000000000
[  699.906125] raw: 0000000000000000 0000000000240000 00000000ffffffff 0000000000000000
[  699.907673] page dumped because: kasan: bad access detected

[  699.909108] Memory state around the buggy address:
[  699.910077]  ffff8801f43af800: 00 f1 f1 f1 f1 00 f4 f4 f4 f3 f3 f3 f3 00 00 00
[  699.911528]  ffff8801f43af880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[  699.912953] >ffff8801f43af900: 00 00 00 00 00 00 00 00 f1 01 f4 f4 f4 f2 f2 f2
[  699.914392]                                                              ^
[  699.915758]  ffff8801f43af980: f2 00 f4 f4 00 00 00 00 f2 00 00 00 00 00 00 00
[  699.917193]  ffff8801f43afa00: 00 00 00 00 00 00 00 00 00 f3 f3 f3 00 00 00 00
[  699.918634] ==================================================================

- Location
https://elixir.bootlin.com/linux/v4.18-rc1/source/fs/f2fs/segment.h#L644

Reported-by Wen Xu <wen.xu@gatech.edu>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch introduces verify_blkaddr to check meta/data block address
with valid range to detect bug earlier.

In addition, once we encounter an invalid blkaddr, notice user to run
fsck to fix, and let the kernel panic.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Jens reported, we'd better assign REQ_RAHEAD to bio by the fact that
->readpages is called only from read-ahead.

In Documentation/filesystems/vfs.txt,

readpages: called by the VM to read pages associated with the address_space
  	object. This is essentially just a vector version of
  	readpage.  Instead of just one page, several pages are
  	requested.
	readpages is only used for read-ahead, so read errors are
  	ignored.  If anything goes wrong, feel free to give up.
Signed-off-by: NJens Axboe <axboe@kernel.dk>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This fixes to support dio having unaligned buffers as buffered writes.

xfs_io -f -d -c "pwrite 0 512" $testfile
 -> okay

xfs_io -f -d -c "pwrite 1 512" $testfile
 -> EINVAL
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Although mixed sync/async IOs can have continuous LBA, as they have
different IO priority, block IO scheduler will add them into different
queues and commit them separately, result in splited IOs which causes
wrose performance.

This patch gives high priority to synchronous IO of nodes, means that
once synchronous flow starts, it can interrupt asynchronous writeback
flow of system flusher, so more big IOs can be expected.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As Ted reported:

"Hi, I was looking at f2fs's sources recently, and I noticed that there
is a very large number of non-static symbols which don't have a f2fs
prefix.  There's well over a hundred (see attached below).

As one example, in fs/f2fs/dir.c there is:

unsigned char get_de_type(struct f2fs_dir_entry *de)

This function is clearly only useful for f2fs, but it has a generic
name.  This means that if any other file system tries to have the same
symbol name, there will be a symbol conflict and the kernel would not
successfully build.  It also means that when someone is looking f2fs
sources, it's not at all obvious whether a function such as
read_data_page(), invalidate_blocks(), is a generic kernel function
found in the fs, mm, or block layers, or a f2fs specific function.

You might want to fix this at some point.  Hopefully Kent's bcachefs
isn't similarly using genericly named functions, since that might
cause conflicts with f2fs's functions --- but just as this would be a
problem that we would rightly insist that Kent fix, this is something
that we should have rightly insisted that f2fs should have fixed
before it was integrated into the mainline kernel.

acquire_orphan_inode
add_ino_entry
add_orphan_inode
allocate_data_block
allocate_new_segments
alloc_nid
alloc_nid_done
alloc_nid_failed
available_free_memory
...."

This patch adds "f2fs_" prefix for all non-static symbols in order to:
a) avoid conflict with other kernel generic symbols;
b) to indicate the function is f2fs specific one instead of generic
one;
Reported-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

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

Configure io_bits with 2 and enable LFS mode, generic/013 reports below dmesg:

BUG: unable to handle kernel NULL pointer dereference at 00000104
*pdpt = 0000000029b7b001 *pde = 0000000000000000
Oops: 0002 [#1] PREEMPT SMP
Modules linked in: crc32_generic zram f2fs(O) rfcomm bnep bluetooth ecdh_generic snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq pcbc joydev snd_seq_device aesni_intel snd_timer aes_i586 snd crypto_simd cryptd soundcore i2c_piix4 serio_raw mac_hid video parport_pc ppdev lp parport hid_generic psmouse usbhid hid e1000
CPU: 0 PID: 11161 Comm: fsstress Tainted: G           O      4.17.0-rc2 #38
Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
EIP: f2fs_submit_page_write+0x28d/0x550 [f2fs]
EFLAGS: 00010206 CPU: 0
EAX: e863dcd8 EBX: 00000000 ECX: 00000100 EDX: 00000200
ESI: e863dcf4 EDI: f6f82768 EBP: e863dbb0 ESP: e863db74
 DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
CR0: 80050033 CR2: 00000104 CR3: 29a62020 CR4: 000406f0
Call Trace:
 do_write_page+0x6f/0xc0 [f2fs]
 write_data_page+0x4a/0xd0 [f2fs]
 do_write_data_page+0x327/0x630 [f2fs]
 __write_data_page+0x34b/0x820 [f2fs]
 __f2fs_write_data_pages+0x42d/0x8c0 [f2fs]
 f2fs_write_data_pages+0x27/0x30 [f2fs]
 do_writepages+0x1a/0x70
 __filemap_fdatawrite_range+0x94/0xd0
 filemap_write_and_wait_range+0x3d/0xa0
 __generic_file_write_iter+0x11a/0x1f0
 f2fs_file_write_iter+0xdd/0x3b0 [f2fs]
 __vfs_write+0xd2/0x150
 vfs_write+0x9b/0x190
 ksys_write+0x45/0x90
 sys_write+0x16/0x20
 do_fast_syscall_32+0xaa/0x22c
 entry_SYSENTER_32+0x4c/0x7b
EIP: 0xb7fc8c51
EFLAGS: 00000246 CPU: 0
EAX: ffffffda EBX: 00000003 ECX: 09cde000 EDX: 00001000
ESI: 00000003 EDI: 00001000 EBP: 00000000 ESP: bfbded38
 DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
Code: e8 f9 77 34 c9 8b 45 e0 8b 80 b8 00 00 00 39 45 d8 0f 84 bb 02 00 00 8b 45 e0 8b 80 b8 00 00 00 8d 50 d8 8b 08 89 55 f0 8b 50 04 <89> 51 04 89 0a c7 00 00 01 00 00 c7 40 04 00 02 00 00 8b 45 dc
EIP: f2fs_submit_page_write+0x28d/0x550 [f2fs] SS:ESP: 0068:e863db74
CR2: 0000000000000104
---[ end trace 4cac79c0d1305ee6 ]---

allocate_data_block will submit all sequential pending IOs sorted by a
FIFO list, If we failed to submit other user's IO due to unaligned write,
we will retry to allocate new block address for current IO, then it will
initialize fio.list again, if fio was in the list before, it can break
FIFO list, result in above panic.

Thread A			Thread B
- do_write_page
 - allocate_data_block
  - list_add_tail
  : fioA cached in FIFO list.
				- do_write_page
				 - allocate_data_block
				  - list_add_tail
				  : fioB cached in FIFO list.
				 - f2fs_submit_page_write
				 : fail to submit IO
				 - allocate_data_block
				  - INIT_LIST_HEAD
 - f2fs_submit_page_write
  - list_del  <-- NULL pointer dereference

This patch adds fio.retry parameter to indicate failure status for each
IO, and avoid bailing out if there is still pending IO in FIFO list for
fixing.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

As description in commit "f2fs: don't drop any page on f2fs_cp_error()
case":

"We still provide readdir() after shtudown, so we should keep pages to
avoid additional IOs."

In order to provider lastest directory structure, let's keep dentry
pages in cache after fs shutdown.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

Introduce clear_radix_tree_dirty_tag to include common codes for cleanup.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

f2fs doesn't allow abuse on atomic write class interface, so except
limiting in-mem pages' total memory usage capacity, we need to limit
atomic-write usage as well when filesystem is seriously fragmented,
otherwise we may run into infinite loop during foreground GC because
target blocks in victim segment are belong to atomic opened file for
long time.

Now, we will detect failure due to atomic write in foreground GC, if
the count exceeds threshold, we will drop all atomic written data in
cache, by this, I expect it can keep our system running safely to
prevent Dos attack.

In addition, his patch adds to show GC skip information in debugfs,
now it just shows count of skipped caused by atomic write.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

This patch changes to detect synchronous writeback more earlier before,
in order to avoid unnecessary page writeback before exiting asynchronous
writeback.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

- rename is_valid_blkaddr() to is_valid_meta_blkaddr() for readability.
- introduce is_valid_blkaddr() for cleanup.

No logic change in this patch.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

1. thread A: commit_inmem_pages submit data into block layer, but
haven't waited it writeback.
2. thread A: commit_inmem_pages update related node.
3. thread B: do checkpoint, flush all nodes to disk.
4. SPOR

Then, atomic file becomes corrupted since nodes is flushed before data.

This patch fixes to treat atomic page as checkpoint guaranteed one,
then in checkpoint, we can make sure all atomic page can be writebacked
with metadata of atomic file.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

RW semphore dio_rwsem in struct f2fs_inode_info is introduced to avoid
race between dio and data gc, but now, it is more wildly used to avoid
foreground operation vs data gc. So rename it to i_gc_rwsem to improve
its readability.
Signed-off-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

pageout() in MM traslates EAGAIN, so calls handle_write_error()
 -> mapping_set_error() -> set_bit(AS_EIO, ...).
 file_write_and_wait_range() will see EIO error, which is critical
 to return value of fsync() followed by atomic_write failure to user.
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>