linux.git/fs/f2fs, branch v6.0 Linux kernel source tree Merge tag 'f2fs-for-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs 2022-08-08T18:18:31+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-08-08T18:18:31+00:00 1daf117f1d6b5056e27353fa289ef1bbcb619e8d Pull f2fs updates from Jaegeuk Kim: "In this cycle, we mainly fixed some corner cases that manipulate a per-file compression flag inappropriately. And, we found f2fs counted valid blocks in a section incorrectly when zone capacity is set, and thus, fixed it with additional sysfs entry to check it easily. Lastly, this series includes several patches with respect to the new atomic write support such as a couple of bug fixes and re-adding atomic_write_abort support that we removed by mistake in the previous release. Enhancements: - add sysfs entries to understand atomic write operations and zone capacity - introduce memory mode to get a hint for low-memory devices - adjust the waiting time of foreground GC - decompress clusters under softirq to avoid non-deterministic latency - do not skip updating inode when retrying to flush node page - enforce single zone capacity Bug fixes: - set the compression/no-compression flags correctly - revive F2FS_IOC_ABORT_VOLATILE_WRITE - check inline_data during compressed inode conversion - understand zone capacity when calculating valid block count As usual, the series includes several minor clean-ups and sanity checks" * tag 'f2fs-for-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (29 commits) f2fs: use onstack pages instead of pvec f2fs: intorduce f2fs_all_cluster_page_ready f2fs: clean up f2fs_abort_atomic_write() f2fs: handle decompress only post processing in softirq f2fs: do not allow to decompress files have FI_COMPRESS_RELEASED f2fs: do not set compression bit if kernel doesn't support f2fs: remove device type check for direct IO f2fs: fix null-ptr-deref in f2fs_get_dnode_of_data f2fs: revive F2FS_IOC_ABORT_VOLATILE_WRITE f2fs: fix to do sanity check on segment type in build_sit_entries() f2fs: obsolete unused MAX_DISCARD_BLOCKS f2fs: fix to avoid use f2fs_bug_on() in f2fs_new_node_page() f2fs: fix to remove F2FS_COMPR_FL and tag F2FS_NOCOMP_FL at the same time f2fs: introduce sysfs atomic write statistics f2fs: don't bother wait_ms by foreground gc f2fs: invalidate meta pages only for post_read required inode f2fs: allow compression of files without blocks f2fs: fix to check inline_data during compressed inode conversion f2fs: Delete f2fs_copy_page() and replace with memcpy_page() f2fs: fix to invalidate META_MAPPING before DIO write ... 
Pull f2fs updates from Jaegeuk Kim:
 "In this cycle, we mainly fixed some corner cases that manipulate a
  per-file compression flag inappropriately. And, we found f2fs counted
  valid blocks in a section incorrectly when zone capacity is set, and
  thus, fixed it with additional sysfs entry to check it easily.

  Lastly, this series includes several patches with respect to the new
  atomic write support such as a couple of bug fixes and re-adding
  atomic_write_abort support that we removed by mistake in the previous
  release.

  Enhancements:
   - add sysfs entries to understand atomic write operations and zone
     capacity
   - introduce memory mode to get a hint for low-memory devices
   - adjust the waiting time of foreground GC
   - decompress clusters under softirq to avoid non-deterministic
     latency
   - do not skip updating inode when retrying to flush node page
   - enforce single zone capacity

  Bug fixes:
   - set the compression/no-compression flags correctly
   - revive F2FS_IOC_ABORT_VOLATILE_WRITE
   - check inline_data during compressed inode conversion
   - understand zone capacity when calculating valid block count

  As usual, the series includes several minor clean-ups and sanity
  checks"

* tag 'f2fs-for-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (29 commits)
  f2fs: use onstack pages instead of pvec
  f2fs: intorduce f2fs_all_cluster_page_ready
  f2fs: clean up f2fs_abort_atomic_write()
  f2fs: handle decompress only post processing in softirq
  f2fs: do not allow to decompress files have FI_COMPRESS_RELEASED
  f2fs: do not set compression bit if kernel doesn't support
  f2fs: remove device type check for direct IO
  f2fs: fix null-ptr-deref in f2fs_get_dnode_of_data
  f2fs: revive F2FS_IOC_ABORT_VOLATILE_WRITE
  f2fs: fix to do sanity check on segment type in build_sit_entries()
  f2fs: obsolete unused MAX_DISCARD_BLOCKS
  f2fs: fix to avoid use f2fs_bug_on() in f2fs_new_node_page()
  f2fs: fix to remove F2FS_COMPR_FL and tag F2FS_NOCOMP_FL at the same time
  f2fs: introduce sysfs atomic write statistics
  f2fs: don't bother wait_ms by foreground gc
  f2fs: invalidate meta pages only for post_read required inode
  f2fs: allow compression of files without blocks
  f2fs: fix to check inline_data during compressed inode conversion
  f2fs: Delete f2fs_copy_page() and replace with memcpy_page()
  f2fs: fix to invalidate META_MAPPING before DIO write
  ...
Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 2022-08-05T23:32:45+00:00 Linus Torvalds torvalds@linux-foundation.org 2022-08-05T23:32:45+00:00 6614a3c3164a5df2b54abb0b3559f51041cf705b Pull MM updates from Andrew Morton: "Most of the MM queue. A few things are still pending. Liam's maple tree rework didn't make it. This has resulted in a few other minor patch series being held over for next time. Multi-gen LRU still isn't merged as we were waiting for mapletree to stabilize. The current plan is to merge MGLRU into -mm soon and to later reintroduce mapletree, with a view to hopefully getting both into 6.1-rc1. Summary: - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe Lin, Yang Shi, Anshuman Khandual and Mike Rapoport - Some kmemleak fixes from Patrick Wang and Waiman Long - DAMON updates from SeongJae Park - memcg debug/visibility work from Roman Gushchin - vmalloc speedup from Uladzislau Rezki - more folio conversion work from Matthew Wilcox - enhancements for coherent device memory mapping from Alex Sierra - addition of shared pages tracking and CoW support for fsdax, from Shiyang Ruan - hugetlb optimizations from Mike Kravetz - Mel Gorman has contributed some pagealloc changes to improve latency and realtime behaviour. - mprotect soft-dirty checking has been improved by Peter Xu - Many other singleton patches all over the place" [ XFS merge from hell as per Darrick Wong in https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ] * tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits) tools/testing/selftests/vm/hmm-tests.c: fix build mm: Kconfig: fix typo mm: memory-failure: convert to pr_fmt() mm: use is_zone_movable_page() helper hugetlbfs: fix inaccurate comment in hugetlbfs_statfs() hugetlbfs: cleanup some comments in inode.c hugetlbfs: remove unneeded header file hugetlbfs: remove unneeded hugetlbfs_ops forward declaration hugetlbfs: use helper macro SZ_1{K,M} mm: cleanup is_highmem() mm/hmm: add a test for cross device private faults selftests: add soft-dirty into run_vmtests.sh selftests: soft-dirty: add test for mprotect mm/mprotect: fix soft-dirty check in can_change_pte_writable() mm: memcontrol: fix potential oom_lock recursion deadlock mm/gup.c: fix formatting in check_and_migrate_movable_page() xfs: fail dax mount if reflink is enabled on a partition mm/memcontrol.c: remove the redundant updating of stats_flush_threshold userfaultfd: don't fail on unrecognized features hugetlb_cgroup: fix wrong hugetlb cgroup numa stat ... 
Pull MM updates from Andrew Morton:
 "Most of the MM queue. A few things are still pending.

  Liam's maple tree rework didn't make it. This has resulted in a few
  other minor patch series being held over for next time.

  Multi-gen LRU still isn't merged as we were waiting for mapletree to
  stabilize. The current plan is to merge MGLRU into -mm soon and to
  later reintroduce mapletree, with a view to hopefully getting both
  into 6.1-rc1.

  Summary:

   - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
     Lin, Yang Shi, Anshuman Khandual and Mike Rapoport

   - Some kmemleak fixes from Patrick Wang and Waiman Long

   - DAMON updates from SeongJae Park

   - memcg debug/visibility work from Roman Gushchin

   - vmalloc speedup from Uladzislau Rezki

   - more folio conversion work from Matthew Wilcox

   - enhancements for coherent device memory mapping from Alex Sierra

   - addition of shared pages tracking and CoW support for fsdax, from
     Shiyang Ruan

   - hugetlb optimizations from Mike Kravetz

   - Mel Gorman has contributed some pagealloc changes to improve
     latency and realtime behaviour.

   - mprotect soft-dirty checking has been improved by Peter Xu

   - Many other singleton patches all over the place"

 [ XFS merge from hell as per Darrick Wong in

   https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]

* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
  tools/testing/selftests/vm/hmm-tests.c: fix build
  mm: Kconfig: fix typo
  mm: memory-failure: convert to pr_fmt()
  mm: use is_zone_movable_page() helper
  hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
  hugetlbfs: cleanup some comments in inode.c
  hugetlbfs: remove unneeded header file
  hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
  hugetlbfs: use helper macro SZ_1{K,M}
  mm: cleanup is_highmem()
  mm/hmm: add a test for cross device private faults
  selftests: add soft-dirty into run_vmtests.sh
  selftests: soft-dirty: add test for mprotect
  mm/mprotect: fix soft-dirty check in can_change_pte_writable()
  mm: memcontrol: fix potential oom_lock recursion deadlock
  mm/gup.c: fix formatting in check_and_migrate_movable_page()
  xfs: fail dax mount if reflink is enabled on a partition
  mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
  userfaultfd: don't fail on unrecognized features
  hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
  ...
f2fs: use onstack pages instead of pvec 2022-08-05T11:20:55+00:00 Fengnan Chang fengnanchang@gmail.com 2022-07-31T03:33:46+00:00 01fc4b9a6ed8eacb64e5609bab7ac963e1c7e486 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> 
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 2022-08-05T11:20:28+00:00 Fengnan Chang changfengnan@vivo.com 2022-07-31T03:33:45+00:00 4f8219f8aa175d5a46703631abaae745592efe29 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> 
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: clean up f2fs_abort_atomic_write() 2022-08-05T11:20:02+00:00 Chao Yu chao.yu@oppo.com 2022-08-04T13:38:21+00:00 e53f8643474a32ddfcfd04e5b22613fdd2a92a52 f2fs_abort_atomic_write() has checked whether current inode is atomic_write one or not, it's redundant to check in its caller, remove it for cleanup. Signed-off-by: Chao Yu <chao.yu@oppo.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
f2fs_abort_atomic_write() has checked whether current inode is
atomic_write one or not, it's redundant to check in its caller,
remove it for cleanup.

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs: handle decompress only post processing in softirq 2022-08-05T11:18:31+00:00 Daeho Jeong daehojeong@google.com 2022-08-02T19:24:37+00:00 bff139b49d9f70c1ac5384aac94554846aa834de 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> 
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: do not allow to decompress files have FI_COMPRESS_RELEASED 2022-08-05T11:18:08+00:00 Jaewook Kim jw5454.kim@samsung.com 2022-08-03T08:53:58+00:00 90be48bd9d29ece3965e5e8b21499b6db166e57b If a file has FI_COMPRESS_RELEASED, all writes for it should not be allowed. However, as of now, in case of compress_mode=user, writes triggered by IOCTLs like F2FS_IOC_DE/COMPRESS_FILE are allowed unexpectly, which could crash that file. To fix it, let's do not allow F2FS_IOC_DE/COMPRESS_IOCTL if a file already has FI_COMPRESS_RELEASED flag. This is the reproduction process: 1. $ touch ./file 2. $ chattr +c ./file 3. $ dd if=/dev/random of=./file bs=4096 count=30 conv=notrunc 4. $ dd if=/dev/zero of=./file bs=4096 count=34 seek=30 conv=notrunc 5. $ sync 6. $ do_compress ./file ; call F2FS_IOC_COMPRESS_FILE 7. $ get_compr_blocks ./file ; call F2FS_IOC_GET_COMPRESS_BLOCKS 8. $ release ./file ; call F2FS_IOC_RELEASE_COMPRESS_BLOCKS 9. $ do_compress ./file ; call F2FS_IOC_COMPRESS_FILE again 10. $ get_compr_blocks ./file ; call F2FS_IOC_GET_COMPRESS_BLOCKS again This reproduction process is tested in 128kb cluster size. You can find compr_blocks has a negative value. Fixes: 5fdb322ff2c2b ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE") Signed-off-by: Junbeom Yeom <junbeom.yeom@samsung.com> Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com> Signed-off-by: Jaewook Kim <jw5454.kim@samsung.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
If a file has FI_COMPRESS_RELEASED, all writes for it should not be
allowed. However, as of now, in case of compress_mode=user, writes
triggered by IOCTLs like F2FS_IOC_DE/COMPRESS_FILE are allowed unexpectly,
which could crash that file.
To fix it, let's do not allow F2FS_IOC_DE/COMPRESS_IOCTL if a file already
has FI_COMPRESS_RELEASED flag.

This is the reproduction process:
1.  $ touch ./file
2.  $ chattr +c ./file
3.  $ dd if=/dev/random of=./file bs=4096 count=30 conv=notrunc
4.  $ dd if=/dev/zero of=./file bs=4096 count=34 seek=30 conv=notrunc
5.  $ sync
6.  $ do_compress ./file      ; call F2FS_IOC_COMPRESS_FILE
7.  $ get_compr_blocks ./file ; call F2FS_IOC_GET_COMPRESS_BLOCKS
8.  $ release ./file          ; call F2FS_IOC_RELEASE_COMPRESS_BLOCKS
9.  $ do_compress ./file      ; call F2FS_IOC_COMPRESS_FILE again
10. $ get_compr_blocks ./file ; call F2FS_IOC_GET_COMPRESS_BLOCKS again

This reproduction process is tested in 128kb cluster size.
You can find compr_blocks has a negative value.

Fixes: 5fdb322ff2c2b ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE")

Signed-off-by: Junbeom Yeom <junbeom.yeom@samsung.com>
Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com>
Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com>
Signed-off-by: Jaewook Kim <jw5454.kim@samsung.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs: do not set compression bit if kernel doesn't support 2022-08-05T11:18:08+00:00 Jaegeuk Kim jaegeuk@kernel.org 2022-08-04T03:33:54+00:00 912f0d6580e743eecf908f5566cc064b63c55908 If kernel doesn't have CONFIG_F2FS_FS_COMPRESSION, a file having FS_COMPR_FL via ioctl(FS_IOC_SETFLAGS) is unaccessible due to f2fs_is_compress_backend_ready(). Let's avoid it. Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
If kernel doesn't have CONFIG_F2FS_FS_COMPRESSION, a file having FS_COMPR_FL via
ioctl(FS_IOC_SETFLAGS) is unaccessible due to f2fs_is_compress_backend_ready().
Let's avoid it.

Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs: remove device type check for direct IO 2022-08-05T11:18:08+00:00 Eunhee Rho eunhee83.rho@samsung.com 2022-08-01T04:40:02+00:00 dbf8e63f48af48f3f0a069fc971c9826312dbfc1 To ensure serialized IOs, f2fs allows only LFS mode for zoned device. Remove redundant check for direct IO. Signed-off-by: Eunhee Rho <eunhee83.rho@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
To ensure serialized IOs, f2fs allows only LFS mode for zoned
device. Remove redundant check for direct IO.

Signed-off-by: Eunhee Rho <eunhee83.rho@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
f2fs: fix null-ptr-deref in f2fs_get_dnode_of_data 2022-08-05T11:18:08+00:00 Ye Bin yebin10@huawei.com 2022-08-01T11:26:04+00:00 4a2c5b7994960fac29cf8a3f4e62855bae1b27d4 There is issue as follows when test f2fs atomic write: F2FS-fs (loop0): Can't find valid F2FS filesystem in 2th superblock F2FS-fs (loop0): invalid crc_offset: 0 F2FS-fs (loop0): f2fs_check_nid_range: out-of-range nid=1, run fsck to fix. F2FS-fs (loop0): f2fs_check_nid_range: out-of-range nid=2, run fsck to fix. ================================================================== BUG: KASAN: null-ptr-deref in f2fs_get_dnode_of_data+0xac/0x16d0 Read of size 8 at addr 0000000000000028 by task rep/1990 CPU: 4 PID: 1990 Comm: rep Not tainted 5.19.0-rc6-next-20220715 #266 Call Trace: <TASK> dump_stack_lvl+0x6e/0x91 print_report.cold+0x49a/0x6bb kasan_report+0xa8/0x130 f2fs_get_dnode_of_data+0xac/0x16d0 f2fs_do_write_data_page+0x2a5/0x1030 move_data_page+0x3c5/0xdf0 do_garbage_collect+0x2015/0x36c0 f2fs_gc+0x554/0x1d30 f2fs_balance_fs+0x7f5/0xda0 f2fs_write_single_data_page+0xb66/0xdc0 f2fs_write_cache_pages+0x716/0x1420 f2fs_write_data_pages+0x84f/0x9a0 do_writepages+0x130/0x3a0 filemap_fdatawrite_wbc+0x87/0xa0 file_write_and_wait_range+0x157/0x1c0 f2fs_do_sync_file+0x206/0x12d0 f2fs_sync_file+0x99/0xc0 vfs_fsync_range+0x75/0x140 f2fs_file_write_iter+0xd7b/0x1850 vfs_write+0x645/0x780 ksys_write+0xf1/0x1e0 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd As 3db1de0e582c commit changed atomic write way which new a cow_inode for atomic write file, and also mark cow_inode as FI_ATOMIC_FILE. When f2fs_do_write_data_page write cow_inode will use cow_inode's cow_inode which is NULL. Then will trigger null-ptr-deref. To solve above issue, introduce FI_COW_FILE flag for COW inode. Fiexes: 3db1de0e582c("f2fs: change the current atomic write way") Signed-off-by: Ye Bin <yebin10@huawei.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> 
There is issue as follows when test f2fs atomic write:
F2FS-fs (loop0): Can't find valid F2FS filesystem in 2th superblock
F2FS-fs (loop0): invalid crc_offset: 0
F2FS-fs (loop0): f2fs_check_nid_range: out-of-range nid=1, run fsck to fix.
F2FS-fs (loop0): f2fs_check_nid_range: out-of-range nid=2, run fsck to fix.
==================================================================
BUG: KASAN: null-ptr-deref in f2fs_get_dnode_of_data+0xac/0x16d0
Read of size 8 at addr 0000000000000028 by task rep/1990

CPU: 4 PID: 1990 Comm: rep Not tainted 5.19.0-rc6-next-20220715 #266
Call Trace:
 <TASK>
 dump_stack_lvl+0x6e/0x91
 print_report.cold+0x49a/0x6bb
 kasan_report+0xa8/0x130
 f2fs_get_dnode_of_data+0xac/0x16d0
 f2fs_do_write_data_page+0x2a5/0x1030
 move_data_page+0x3c5/0xdf0
 do_garbage_collect+0x2015/0x36c0
 f2fs_gc+0x554/0x1d30
 f2fs_balance_fs+0x7f5/0xda0
 f2fs_write_single_data_page+0xb66/0xdc0
 f2fs_write_cache_pages+0x716/0x1420
 f2fs_write_data_pages+0x84f/0x9a0
 do_writepages+0x130/0x3a0
 filemap_fdatawrite_wbc+0x87/0xa0
 file_write_and_wait_range+0x157/0x1c0
 f2fs_do_sync_file+0x206/0x12d0
 f2fs_sync_file+0x99/0xc0
 vfs_fsync_range+0x75/0x140
 f2fs_file_write_iter+0xd7b/0x1850
 vfs_write+0x645/0x780
 ksys_write+0xf1/0x1e0
 do_syscall_64+0x3b/0x90
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

As 3db1de0e582c commit changed atomic write way which new a cow_inode for
atomic write file, and also mark cow_inode as FI_ATOMIC_FILE.
When f2fs_do_write_data_page write cow_inode will use cow_inode's cow_inode
which is NULL. Then will trigger null-ptr-deref.
To solve above issue, introduce FI_COW_FILE flag for COW inode.

Fiexes: 3db1de0e582c("f2fs: change the current atomic write way")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>