linux/fs/f2fs
Chao Yu 186857c5a1 f2fs: fix potential recursive call when enabling data_flush
As Hagbard Celine reported:

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

Same options just without data_flush gives no problems.

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

......

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

......

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

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

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

In order to fix this issue, let's detect such condition in __write_data_page()
and just skip calling f2fs_balance_fs() recursively.

Reported-by: Hagbard Celine <hagbardcelin@gmail.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-04-05 09:34:14 -07:00
..
acl.c f2fs: use kvmalloc, if kmalloc is failed 2018-12-26 15:16:53 -08:00
acl.h f2fs: add SPDX license identifiers 2018-09-12 13:07:10 -07:00
checkpoint.c f2fs: fix potential recursive call when enabling data_flush 2019-04-05 09:34:14 -07:00
data.c f2fs: fix potential recursive call when enabling data_flush 2019-04-05 09:34:14 -07:00
debug.c f2fs: no need to check return value of debugfs_create functions 2019-01-22 14:25:25 +01:00
dir.c f2fs-for-5.1-rc1 2019-03-15 13:42:53 -07:00
extent_cache.c f2fs: fix to initialize variable to avoid UBSAN/smatch warning 2019-01-22 15:31:26 -08:00
f2fs.h f2fs: improve discard handling with multi-device volumes 2019-04-05 09:33:55 -07:00
file.c f2fs: Fix use of number of devices 2019-04-05 09:33:54 -07:00
gc.c f2fs: Fix use of number of devices 2019-04-05 09:33:54 -07:00
gc.h f2fs: add SPDX license identifiers 2018-09-12 13:07:10 -07:00
hash.c f2fs: add SPDX license identifiers 2018-09-12 13:07:10 -07:00
inline.c f2fs: fix to avoid deadlock in f2fs_read_inline_dir() 2019-03-12 19:07:09 -07:00
inode.c f2fs-for-5.1-rc1 2019-03-15 13:42:53 -07:00
Kconfig fscrypt: remove filesystem specific build config option 2019-01-23 23:56:43 -05:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
namei.c f2fs-for-5.1-rc1 2019-03-15 13:42:53 -07:00
node.c f2fs: fix to add refcount once page is tagged PG_private 2019-03-12 18:59:19 -07:00
node.h f2fs: check PageWriteback flag for ordered case 2018-12-26 15:16:56 -08:00
recovery.c f2fs: check PageWriteback flag for ordered case 2018-12-26 15:16:56 -08:00
segment.c f2fs: improve discard handling with multi-device volumes 2019-04-05 09:33:55 -07:00
segment.h f2fs: don't wake up too frequently, if there is lots of IOs 2019-02-15 20:59:45 -08:00
shrinker.c f2fs: fix sbi->extent_list corruption issue 2018-12-26 15:16:54 -08:00
super.c f2fs: Reduce zoned block device memory usage 2019-04-05 09:33:55 -07:00
sysfs.c f2fs-for-5.1-rc1 2019-03-15 13:42:53 -07:00
trace.c f2fs: do not use mutex lock in atomic context 2019-03-05 19:58:06 -08:00
trace.h f2fs: add SPDX license identifiers 2018-09-12 13:07:10 -07:00
xattr.c f2fs: fix to adapt small inline xattr space in __find_inline_xattr() 2019-03-12 19:02:26 -07:00
xattr.h f2fs: fix to do sanity check with inode.i_inline_xattr_size 2019-03-12 19:02:26 -07:00