Commit Graph

733 Commits

Author SHA1 Message Date
Linus Torvalds 5d170fe435 Merge tag 'f2fs-for-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
 "This round looks fairly small comparing to the previous updates and
  includes mostly minor bug fixes. Nevertheless, as we've still
  interested in improving the stability, Chao added some debugging
  methods to diagnoze subtle runtime inconsistency problem.

  Enhancements:
   - store all the corruption or failure reasons in superblock
   - detect meta inode, summary info, and block address inconsistency
   - increase the limit for reserve_root for low-end devices
   - add the number of compressed IO in iostat

  Bug fixes:
   - DIO write fix for zoned devices
   - do out-of-place writes for cold files
   - fix some stat updates (FS_CP_DATA_IO, dirty page count)
   - fix race condition on setting FI_NO_EXTENT flag
   - fix data races when freezing super
   - fix wrong continue condition check in GC
   - do not allow ATGC for LFS mode

  In addition, there're some code enhancement and clean-ups as usual"

* tag 'f2fs-for-6.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (32 commits)
  f2fs: change to use atomic_t type form sbi.atomic_files
  f2fs: account swapfile inodes
  f2fs: allow direct read for zoned device
  f2fs: support recording errors into superblock
  f2fs: support recording stop_checkpoint reason into super_block
  f2fs: remove the unnecessary check in f2fs_xattr_fiemap
  f2fs: introduce cp_status sysfs entry
  f2fs: fix to detect corrupted meta ino
  f2fs: fix to account FS_CP_DATA_IO correctly
  f2fs: code clean and fix a type error
  f2fs: add "c_len" into trace_f2fs_update_extent_tree_range for compressed file
  f2fs: fix to do sanity check on summary info
  f2fs: port to vfs{g,u}id_t and associated helpers
  f2fs: fix to do sanity check on destination blkaddr during recovery
  f2fs: let FI_OPU_WRITE override FADVISE_COLD_BIT
  f2fs: fix race condition on setting FI_NO_EXTENT flag
  f2fs: remove redundant check in f2fs_sanity_check_cluster
  f2fs: add static init_idisk_time function to reduce the code
  f2fs: fix typo
  f2fs: fix wrong dirty page count when race between mmap and fallocate.
  ...
2022-10-10 20:28:41 -07:00
Chao Yu 8ec071c363 f2fs: account swapfile inodes
In order to check count of opened swapfile inodes.

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-10-07 12:56:45 -07:00
Chao Yu 95fa90c9e5 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>
2022-10-04 13:31:45 -07:00
Chao Yu a9cfee0ef9 f2fs: support recording stop_checkpoint reason into super_block
This patch supports to record stop_checkpoint error into
f2fs_super_block.s_stop_reason[].

Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-10-04 13:31:44 -07:00
Zhang Qilong ca7efd71c3 f2fs: remove the unnecessary check in f2fs_xattr_fiemap
Whehter or not error occurs, checking "err == 1" is unnecessary
in f2fs_xattr_fiemap(), and just remove it here.

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-10-04 13:31:44 -07:00
Chao Yu d80afefb17 f2fs: fix to account FS_CP_DATA_IO correctly
f2fs_inode_info.cp_task was introduced for FS_CP_DATA_IO accounting
since commit b0af6d491a ("f2fs: add app/fs io stat").

However, cp_task usage coverage has been increased due to below
commits:
commit 040d2bb318 ("f2fs: fix to avoid deadloop if data_flush is on")
commit 186857c5a1 ("f2fs: fix potential recursive call when enabling data_flush")

So that, if data_flush mountoption is on, when data flush was
triggered from background, the IO from data flush will be accounted
as checkpoint IO type incorrectly.

In order to fix this issue, this patch splits cp_task into two:
a) cp_task: used for IO accounting
b) wb_task: used to avoid deadlock

Fixes: 040d2bb318 ("f2fs: fix to avoid deadloop if data_flush is on")
Fixes: 186857c5a1 ("f2fs: fix potential recursive call when enabling data_flush")
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-10-04 13:31:44 -07:00
Zhang Qilong 544b53dadc f2fs: code clean and fix a type error
ERROR: code indent should use tabs where possible
ERROR: spaces required around that ':'
ERROR: incorrect tab

Found serveral code type errors when review the code and fix it.
There is no function change.

Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-10-04 13:31:44 -07:00
Weichao Guo f3b23c785a f2fs: let FI_OPU_WRITE override FADVISE_COLD_BIT
Cold files may be fragmented due to SSR, defragment is needed as
sequential reads are dominant scenarios of these files. FI_OPU_WRITE
should override FADVISE_COLD_BIT to avoid defragment fails.

Signed-off-by: Weichao Guo <guoweichao@oppo.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-10-04 13:31:43 -07:00
Shuqi Zhang 9b7eadd9bd f2fs: fix wrong dirty page count when race between mmap and fallocate.
This is a BUG_ON issue as follows when running xfstest-generic-503:
WARNING: CPU: 21 PID: 1385 at fs/f2fs/inode.c:762 f2fs_evict_inode+0x847/0xaa0
Modules linked in:
CPU: 21 PID: 1385 Comm: umount Not tainted 5.19.0-rc5+ #73
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014

Call Trace:
evict+0x129/0x2d0
dispose_list+0x4f/0xb0
evict_inodes+0x204/0x230
generic_shutdown_super+0x5b/0x1e0
kill_block_super+0x29/0x80
kill_f2fs_super+0xe6/0x140
deactivate_locked_super+0x44/0xc0
deactivate_super+0x79/0x90
cleanup_mnt+0x114/0x1a0
__cleanup_mnt+0x16/0x20
task_work_run+0x98/0x100
exit_to_user_mode_prepare+0x3d0/0x3e0
syscall_exit_to_user_mode+0x12/0x30
do_syscall_64+0x42/0x80
entry_SYSCALL_64_after_hwframe+0x46/0xb0

Function flow analysis when BUG occurs:
f2fs_fallocate                    mmap
                                  do_page_fault
                                    pte_spinlock  // ---lock_pte
                                    do_wp_page
                                      wp_page_shared
                                        pte_unmap_unlock   // unlock_pte
                                          do_page_mkwrite
                                          f2fs_vm_page_mkwrite
                                            down_read(invalidate_lock)
                                            lock_page
                                            if (PageMappedToDisk(page))
                                              goto out;
                                            // set_page_dirty  --NOT RUN
                                            out: up_read(invalidate_lock);
                                        finish_mkwrite_fault // unlock_pte
f2fs_collapse_range
  down_write(i_mmap_sem)
  truncate_pagecache
    unmap_mapping_pages
      i_mmap_lock_write // down_write(i_mmap_rwsem)
        ......
        zap_pte_range
          pte_offset_map_lock // ---lock_pte
           set_page_dirty
            f2fs_dirty_data_folio
              if (!folio_test_dirty(folio)) {
                                        fault_dirty_shared_page
                                          set_page_dirty
                                            f2fs_dirty_data_folio
                                              if (!folio_test_dirty(folio)) {
                                                filemap_dirty_folio
                                                f2fs_update_dirty_folio // ++
                                              }
                                            unlock_page
                filemap_dirty_folio
                f2fs_update_dirty_folio // page count++
              }
          pte_unmap_unlock  // --unlock_pte
      i_mmap_unlock_write  // up_write(i_mmap_rwsem)
  truncate_inode_pages
  up_write(i_mmap_sem)

When race happens between mmap-do_page_fault-wp_page_shared and
fallocate-truncate_pagecache-zap_pte_range, the zap_pte_range calls
function set_page_dirty without page lock. Besides, though
truncate_pagecache has immap and pte lock, wp_page_shared calls
fault_dirty_shared_page without any. In this case, two threads race
in f2fs_dirty_data_folio function. Page is set to dirty only ONCE,
but the count is added TWICE by calling filemap_dirty_folio.
Thus the count of dirty page cannot accord with the real dirty pages.

Following is the solution to in case of race happens without any lock.
Since folio_test_set_dirty in filemap_dirty_folio is atomic, judge return
value will not be at risk of race.

Signed-off-by: Shuqi Zhang <zhangshuqi3@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-10-04 13:31:42 -07:00
Eric Biggers 14db0b3c7b fscrypt: 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 decryption errors.  Instead, if
a decryption 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.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <chao@kernel.org> # for f2fs part
Link: https://lore.kernel.org/r/20220815235052.86545-2-ebiggers@kernel.org
2022-09-06 15:15:56 -07:00
Chao Yu 34a2352560 f2fs: iostat: support accounting compressed IO
Previously, we supported to account FS_CDATA_READ_IO type IO only,
in this patch, it adds to account more type IO for compressed file:
- APP_BUFFERED_CDATA_IO
- APP_MAPPED_CDATA_IO
- FS_CDATA_IO
- APP_BUFFERED_CDATA_READ_IO
- APP_MAPPED_CDATA_READ_IO

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-08-29 21:15:51 -07:00
Linus Torvalds 1daf117f1d Merge tag 'f2fs-for-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
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
  ...
2022-08-08 11:18:31 -07:00
Fengnan Chang 01fc4b9a6e 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>
2022-08-05 04:20:55 -07:00
Fengnan Chang 4f8219f8aa 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>
2022-08-05 04:20:28 -07:00
Daeho Jeong bff139b49d 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>
2022-08-05 04:18:31 -07:00
Linus Torvalds f00654007f Merge tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache
Pull folio updates from Matthew Wilcox:

 - Fix an accounting bug that made NR_FILE_DIRTY grow without limit
   when running xfstests

 - Convert more of mpage to use folios

 - Remove add_to_page_cache() and add_to_page_cache_locked()

 - Convert find_get_pages_range() to filemap_get_folios()

 - Improvements to the read_cache_page() family of functions

 - Remove a few unnecessary checks of PageError

 - Some straightforward filesystem conversions to use folios

 - Split PageMovable users out from address_space_operations into
   their own movable_operations

 - Convert aops->migratepage to aops->migrate_folio

 - Remove nobh support (Christoph Hellwig)

* tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache: (78 commits)
  fs: remove the NULL get_block case in mpage_writepages
  fs: don't call ->writepage from __mpage_writepage
  fs: remove the nobh helpers
  jfs: stop using the nobh helper
  ext2: remove nobh support
  ntfs3: refactor ntfs_writepages
  mm/folio-compat: Remove migration compatibility functions
  fs: Remove aops->migratepage()
  secretmem: Convert to migrate_folio
  hugetlb: Convert to migrate_folio
  aio: Convert to migrate_folio
  f2fs: Convert to filemap_migrate_folio()
  ubifs: Convert to filemap_migrate_folio()
  btrfs: Convert btrfs_migratepage to migrate_folio
  mm/migrate: Add filemap_migrate_folio()
  mm/migrate: Convert migrate_page() to migrate_folio()
  nfs: Convert to migrate_folio
  btrfs: Convert btree_migratepage to migrate_folio
  mm/migrate: Convert expected_page_refs() to folio_expected_refs()
  mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio()
  ...
2022-08-03 10:35:43 -07:00
Matthew Wilcox (Oracle) 1d5b9bd656 f2fs: Convert to filemap_migrate_folio()
filemap_migrate_folio() fits f2fs's needs perfectly.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Chao Yu <chao@kernel.org>
2022-08-02 12:34:04 -04:00
Daeho Jeong f8e2f32bcd f2fs: introduce sysfs atomic write statistics
introduce the below 4 new sysfs node for atomic write statistics.
- current_atomic_write: the total current atomic write block count,
                        which is not committed yet.
- peak_atomic_write: the peak value of total current atomic write block
                     count after boot.
- committed_atomic_block: the accumulated total committed atomic write
                          block count after boot.
- revoked_atomic_block: the accumulated total revoked atomic write block
                        count after boot.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-07-30 20:17:07 -07:00
Chao Yu 0d5b9d8156 f2fs: invalidate meta pages only for post_read required inode
After commit e3b49ea368 ("f2fs: invalidate META_MAPPING before
IPU/DIO write"), invalidate_mapping_pages() will be called to
avoid race condition in between IPU/DIO and readahead for GC.

However, readahead flow is only used for post_read required inode,
so this patch adds check condition to avoids unnecessary page cache
invalidating for non-post_read inode.

Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-07-30 20:17:06 -07:00
Chao Yu 67ca06872e f2fs: fix to invalidate META_MAPPING before DIO write
Quoted from commit e3b49ea368 ("f2fs: invalidate META_MAPPING before
IPU/DIO write")

"
Encrypted pages during GC are read and cached in META_MAPPING.
However, due to cached pages in META_MAPPING, there is an issue where
newly written pages are lost by IPU or DIO writes.

Thread A - f2fs_gc()            Thread B
/* phase 3 */
down_write(i_gc_rwsem)
ra_data_block()       ---- (a)
up_write(i_gc_rwsem)
                                f2fs_direct_IO() :
                                 - down_read(i_gc_rwsem)
                                 - __blockdev_direct_io()
                                 - get_data_block_dio_write()
                                 - f2fs_dio_submit_bio()  ---- (b)
                                 - up_read(i_gc_rwsem)
/* phase 4 */
down_write(i_gc_rwsem)
move_data_block()     ---- (c)
up_write(i_gc_rwsem)

(a) In phase 3 of f2fs_gc(), up-to-date page is read from storage and
    cached in META_MAPPING.
(b) In thread B, writing new data by IPU or DIO write on same blkaddr as
    read in (a). cached page in META_MAPPING become out-dated.
(c) In phase 4 of f2fs_gc(), out-dated page in META_MAPPING is copied to
    new blkaddr. In conclusion, the newly written data in (b) is lost.

To address this issue, invalidating pages in META_MAPPING before IPU or
DIO write.
"

In previous commit, we missed to cover extent cache hit case, and passed
wrong value for parameter @end of invalidate_mapping_pages(), fix both
issues.

Fixes: 6aa58d8ad2 ("f2fs: readahead encrypted block during GC")
Fixes: e3b49ea368 ("f2fs: invalidate META_MAPPING before IPU/DIO write")
Cc: Hyeong-Jun Kim <hj514.kim@samsung.com>
Signed-off-by: Chao Yu <chao.yu@oppo.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-07-30 20:16:20 -07:00
Bart Van Assche 7649c873c1 fs/f2fs: Use the enum req_op and blk_opf_t types
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags.

Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-53-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-14 12:14:32 -06:00
Linus Torvalds 1501f707d2 Merge tag 'f2fs-for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs
Pull f2fs updates from Jaegeuk Kim:
 "In this round, we've refactored the existing atomic write support
  implemented by in-memory operations to have storing data in disk
  temporarily, which can give us a benefit to accept more atomic writes.

  At the same time, we removed the existing volatile write support.

  We've also revisited the file pinning and GC flows and found some
  corner cases which contributeed abnormal system behaviours.

  As usual, there're several minor code refactoring for readability,
  sanity check, and clean ups.

  Enhancements:

   - allow compression for mmap files in compress_mode=user

   - kill volatile write support

   - change the current atomic write way

   - give priority to select unpinned section for foreground GC

   - introduce data read/write showing path info

   - remove unnecessary f2fs_lock_op in f2fs_new_inode

  Bug fixes:

   - fix the file pinning flow during checkpoint=disable and GCs

   - fix foreground and background GCs to select the right victims and
     get free sections on time

   - fix GC flags on defragmenting pages

   - avoid an infinite loop to flush node pages

   - fix fallocate to use file_modified to update permissions
     consistently"

* tag 'f2fs-for-5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (40 commits)
  f2fs: fix to tag gcing flag on page during file defragment
  f2fs: replace F2FS_I(inode) and sbi by the local variable
  f2fs: add f2fs_init_write_merge_io function
  f2fs: avoid unneeded error handling for revoke_entry_slab allocation
  f2fs: allow compression for mmap files in compress_mode=user
  f2fs: fix typo in comment
  f2fs: make f2fs_read_inline_data() more readable
  f2fs: fix to do sanity check for inline inode
  f2fs: fix fallocate to use file_modified to update permissions consistently
  f2fs: don't use casefolded comparison for "." and ".."
  f2fs: do not stop GC when requiring a free section
  f2fs: keep wait_ms if EAGAIN happens
  f2fs: introduce f2fs_gc_control to consolidate f2fs_gc parameters
  f2fs: reject test_dummy_encryption when !CONFIG_FS_ENCRYPTION
  f2fs: kill volatile write support
  f2fs: change the current atomic write way
  f2fs: don't need inode lock for system hidden quota
  f2fs: stop allocating pinned sections if EAGAIN happens
  f2fs: skip GC if possible when checkpoint disabling
  f2fs: give priority to select unpinned section for foreground GC
  ...
2022-05-31 16:52:59 -07:00
Yufen Yu 908ea65416 f2fs: add f2fs_init_write_merge_io function
Almost all other initialization of variables in f2fs_fill_super are
extraced to a single function. Also do it for write_io[], which can
make code more clean.

This patch just refactors the code, theres no functional change.

Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Reviewed-by: Chao Yu <chao@kernel.org>
[Jaegeuk Kim: clean up]
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-05-25 10:48:56 -07:00
Jaegeuk Kim 7bc155fec5 f2fs: kill volatile write support
There's no user, since all can use atomic writes simply.
Let's kill it.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-05-12 10:14:03 -07:00
Daeho Jeong 3db1de0e58 f2fs: change the current atomic write way
Current atomic write has three major issues like below.
 - keeps the updates in non-reclaimable memory space and they are even
   hard to be migrated, which is not good for contiguous memory
   allocation.
 - disk spaces used for atomic files cannot be garbage collected, so
   this makes it difficult for the filesystem to be defragmented.
 - If atomic write operations hit the threshold of either memory usage
   or garbage collection failure count, All the atomic write operations
   will fail immediately.

To resolve the issues, I will keep a COW inode internally for all the
updates to be flushed from memory, when we need to flush them out in a
situation like high memory pressure. These COW inodes will be tagged
as orphan inodes to be reclaimed in case of sudden power-cut or system
failure during atomic writes.

Signed-off-by: Daeho Jeong <daehojeong@google.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2022-05-12 10:14:03 -07:00