linux/fs/ext4
Baokun Li eee22187b5 ext4: add inode table check in __ext4_get_inode_loc to aovid possible infinite loop
In do_writepages, if the value returned by ext4_writepages is "-ENOMEM"
and "wbc->sync_mode == WB_SYNC_ALL", retry until the condition is not met.

In __ext4_get_inode_loc, if the bh returned by sb_getblk is NULL,
the function returns -ENOMEM.

In __getblk_slow, if the return value of grow_buffers is less than 0,
the function returns NULL.

When the three processes are connected in series like the following stack,
an infinite loop may occur:

do_writepages					<--- keep retrying
 ext4_writepages
  mpage_map_and_submit_extent
   mpage_map_one_extent
    ext4_map_blocks
     ext4_ext_map_blocks
      ext4_ext_handle_unwritten_extents
       ext4_ext_convert_to_initialized
        ext4_split_extent
         ext4_split_extent_at
          __ext4_ext_dirty
           __ext4_mark_inode_dirty
            ext4_reserve_inode_write
             ext4_get_inode_loc
              __ext4_get_inode_loc		<--- return -ENOMEM
               sb_getblk
                __getblk_gfp
                 __getblk_slow			<--- return NULL
                  grow_buffers
                   grow_dev_page		<--- return -ENXIO
                    ret = (block < end_block) ? 1 : -ENXIO;

In this issue, bg_inode_table_hi is overwritten as an incorrect value.
As a result, `block < end_block` cannot be met in grow_dev_page.
Therefore, __ext4_get_inode_loc always returns '-ENOMEM' and do_writepages
keeps retrying. As a result, the writeback process is in the D state due
to an infinite loop.

Add a check on inode table block in the __ext4_get_inode_loc function by
referring to ext4_read_inode_bitmap to avoid this infinite loop.

Cc: stable@kernel.org
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/20220817132701.3015912-3-libaokun1@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2022-12-01 10:46:54 -05:00
..
.kunitconfig ext4: add .kunitconfig fragment to enable ext4-specific tests 2021-02-11 23:16:30 -05:00
acl.c fs/ext4: fix comments mentioning i_mutex 2022-02-03 10:57:53 -05:00
acl.h vfs: add rcu argument to ->get_acl() callback 2021-08-18 22:08:24 +02:00
balloc.c ext4: use ext4_debug() instead of jbd_debug() 2022-08-02 23:52:19 -04:00
bitmap.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
block_validity.c ext4: add ext4_sb_block_valid() refactored out of ext4_inode_block_valid() 2022-02-25 21:34:56 -05:00
crypto.c ext4: refactor and move ext4_ioctl_get_encryption_pwsalt() 2022-05-21 22:24:24 -04:00
dir.c ext4: fix spelling errors in comments 2022-05-11 15:19:06 -04:00
ext4_extents.h ext4: fix sparse warnings 2021-08-30 23:36:50 -04:00
ext4_jbd2.c ext4: use ext4_debug() instead of jbd_debug() 2022-08-02 23:52:19 -04:00
ext4_jbd2.h fs/ext4: fix comments mentioning i_mutex 2022-02-03 10:57:53 -05:00
ext4.h The first two changes that involve files outside of fs/ext4: 2022-10-06 17:45:53 -07:00
extents_status.c ext4: factor out ext4_free_ext_path() 2022-09-30 23:46:54 -04:00
extents_status.h ext4: fix extent_status trace points 2020-01-25 02:03:03 -05:00
extents.c fs/ext4: replace ternary operator with min()/max() and min_t() 2022-11-29 16:10:49 -05:00
fast_commit.c ext4: fix fortify warning in fs/ext4/fast_commit.c:1551 2022-11-06 01:07:59 -04:00
fast_commit.h ext4: introduce EXT4_FC_TAG_BASE_LEN helper 2022-09-30 23:46:54 -04:00
file.c The first two changes that involve files outside of fs/ext4: 2022-10-06 17:45:53 -07:00
fsmap.c treewide: Change list_sort to use const pointers 2021-04-08 16:04:22 -07:00
fsmap.h ext4: fsmap: fix the block/inode bitmap comment 2021-06-24 09:48:29 -04:00
fsync.c block: use an on-stack bio in blkdev_issue_flush 2021-01-27 09:51:48 -07:00
hash.c unicode: clean up the Kconfig symbol confusion 2022-01-20 19:57:24 -05:00
ialloc.c treewide: use get_random_u32() when possible 2022-10-11 17:42:58 -06:00
indirect.c ext4: use ext4_debug() instead of jbd_debug() 2022-08-02 23:52:19 -04:00
inline.c fs/ext4: replace ternary operator with min()/max() and min_t() 2022-11-29 16:10:49 -05:00
inode-test.c fs: ext4: Modify inode-test.c to use KUnit parameterized testing feature 2020-12-02 16:07:25 -07:00
inode.c ext4: add inode table check in __ext4_get_inode_loc to aovid possible infinite loop 2022-12-01 10:46:54 -05:00
ioctl.c Fix a number of bug fixes, including some regressions, the most 2022-11-06 10:30:29 -08:00
Kconfig ext: EXT4_KUNIT_TESTS should depend on EXT4_FS instead of selecting it 2021-02-11 23:12:59 -05:00
Makefile ext4: move ext4 crypto code to its own file crypto.c 2022-05-21 22:24:24 -04:00
mballoc.c ext4: fixup possible uninitialized variable access in ext4_mb_choose_next_group_cr1() 2022-09-26 13:21:05 -04:00
mballoc.h ext4: use buckets for cr 1 block scan instead of rbtree 2022-09-21 22:12:03 -04:00
migrate.c ext4: fix warning in 'ext4_da_release_space' 2022-11-06 01:07:59 -04:00
mmp.c treewide: use get_random_u32() when possible 2022-10-11 17:42:58 -06:00
move_extent.c ext4: factor out ext4_free_ext_path() 2022-09-30 23:46:54 -04:00
namei.c Fix a number of bug fixes, including some regressions, the most 2022-11-06 10:30:29 -08:00
orphan.c ext4: use ext4_debug() instead of jbd_debug() 2022-08-02 23:52:19 -04:00
page-io.c ext4: fix incorrect comment in ext4_bio_write_page() 2022-06-16 11:03:16 -04:00
readpage.c fscrypt: stop using PG_error to track error status 2022-09-06 15:15:56 -07:00
resize.c ext4: update the backup superblock's at the end of the online resize 2022-10-27 23:21:40 -04:00
super.c fs/ext4: replace ternary operator with min()/max() and min_t() 2022-11-29 16:10:49 -05:00
symlink.c ext4: fix reading leftover inlined symlinks 2022-08-02 23:37:50 -04:00
sysfs.c unicode: clean up the Kconfig symbol confusion 2022-01-20 19:57:24 -05:00
truncate.h ext4: Convert to use mapping->invalidate_lock 2021-07-13 14:29:00 +02:00
verity.c - Alistair Popple has a series which addresses a race which causes page 2022-10-14 12:28:43 -07:00
xattr_hurd.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
xattr_security.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
xattr_trusted.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
xattr_user.c acl: handle idmapped mounts 2021-01-24 14:27:17 +01:00
xattr.c ext4: fix i_version handling in ext4 2022-09-30 23:46:52 -04:00
xattr.h ext4: remove EA inode entry from mbcache on inode eviction 2022-08-02 23:56:25 -04:00