kernel/linux.git/fs/ext4/ext4_jbd2.c, branch v6.12.107

ext4: wait for ongoing I/O to complete before freeing blocks

2025-10-23T14:20:19+00:00

commit 328a782cb138029182e521c08f50eb1587db955d upstream. When freeing metadata blocks in nojournal mode, ext4_forget() calls bforget() to clear the dirty flag on the buffer_head and remvoe associated mappings. This is acceptable if the metadata has not yet begun to be written back. However, if the write-back has already started but is not yet completed, ext4_forget() will have no effect. Subsequently, ext4_mb_clear_bb() will immediately return the block to the mb allocator. This block can then be reallocated immediately, potentially causing an data corruption issue. Fix this by clearing the buffer's dirty flag and waiting for the ongoing I/O to complete, ensuring that no further writes to stale data will occur. Fixes: 16e08b14a455 ("ext4: cleanup clean_bdev_aliases() calls") Cc: stable@kernel.org Reported-by: Gao Xiang Closes: https://lore.kernel.org/linux-ext4/a9417096-9549-4441-9878-b1955b899b4e@huaweicloud.com/ Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Message-ID: <20250916093337.3161016-3-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

use ->bd_mapping instead of ->bd_inode->i_mapping

2024-05-03T06:36:51+00:00

Just the low-hanging fruit... Signed-off-by: Al Viro Link: https://lore.kernel.org/r/20240411145346.2516848-2-viro@zeniv.linux.org.uk Signed-off-by: Christian Brauner

ext4: move ext4_check_bdev_write_error() into nojournal mode

2024-01-05T04:42:21+00:00

Since JBD2 takes care of all metadata writeback errors of fs dev, ext4_check_bdev_write_error() is useful only in nojournal mode. Move it into '!ext4_handle_valid(handle)' branch. Signed-off-by: Zhihao Cheng Suggested-by: Jan Kara Reviewed-by: Jan Kara Link: https://lore.kernel.org/r/20231213013224.2100050-6-chengzhihao1@huawei.com Signed-off-by: Theodore Ts'o

Merge tag 'ext4_for_linus-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2023-08-31T22:18:15+00:00

Pull ext4 updates from Ted Ts'o: "Many ext4 and jbd2 cleanups and bug fixes: - Cleanups in the ext4 remount code when going to and from read-only - Cleanups in ext4's multiblock allocator - Cleanups in the jbd2 setup/mounting code paths - Performance improvements when appending to a delayed allocation file - Miscellaneous syzbot and other bug fixes" * tag 'ext4_for_linus-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (60 commits) ext4: fix slab-use-after-free in ext4_es_insert_extent() libfs: remove redundant checks of s_encoding ext4: remove redundant checks of s_encoding ext4: reject casefold inode flag without casefold feature ext4: use LIST_HEAD() to initialize the list_head in mballoc.c ext4: do not mark inode dirty every time when appending using delalloc ext4: rename s_error_work to s_sb_upd_work ext4: add periodic superblock update check ext4: drop dio overwrite only flag and associated warning ext4: add correct group descriptors and reserved GDT blocks to system zone ext4: remove unused function declaration ext4: mballoc: avoid garbage value from err ext4: use sbi instead of EXT4_SB(sb) in ext4_mb_new_blocks_simple() ext4: change the type of blocksize in ext4_mb_init_cache() ext4: fix unttached inode after power cut with orphan file feature enabled jbd2: correct the end of the journal recovery scan range ext4: ext4_get_{dev}_journal return proper error value ext4: cleanup ext4_get_dev_journal() and ext4_get_journal() jbd2: jbd2_journal_init_{dev,inode} return proper error return value jbd2: drop useless error tag in jbd2_journal_wipe() ...

ext4: don't use bdev->bd_super in __ext4_journal_get_write_access

2023-08-09T06:16:55+00:00

__ext4_journal_get_write_access already has a super_block available, and there is no need to go from that to the bdev to go back to the owning super_block. Signed-off-by: Christoph Hellwig Message-Id: <20230807112625.652089-3-hch@lst.de> Signed-off-by: Christian Brauner

ext4: warn on read-only filesystem in ext4_journal_check_start()

2023-07-29T22:37:53+00:00

Now that filesystem abort marks the filesystem as shutdown, we shouldn't be ever hitting the sb_rdonly() check in ext4_journal_check_start(). Since this is a suitable place for catching all sorts of programming errors, convert the check to WARN_ON instead of dropping it. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230616165109.21695-7-jack@suse.cz Signed-off-by: Theodore Ts'o

ext4: make ext4_forced_shutdown() take struct super_block

2023-07-29T22:37:24+00:00

Currently ext4_forced_shutdown() takes struct ext4_sb_info but most callers need to get it from struct super_block anyway. So just pass in struct super_block to save all callers from some boilerplate code. No functional changes. Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230616165109.21695-3-jack@suse.cz Signed-off-by: Theodore Ts'o

ext4: split ext4_journal_start trace for debug

2022-12-01T15:46:54+00:00

we might want to know why jbd2 thread using high io for detail, split ext4_journal_start trace to ext4_journal_start_sb and ext4_journal_start_inode, show ino and handle type when possible. Signed-off-by: changfengnan Link: https://lore.kernel.org/r/20221008120518.74870-1-changfengnan@bytedance.com Signed-off-by: Theodore Ts'o

ext4: use ext4_debug() instead of jbd_debug()

2022-08-03T03:52:19+00:00

We use jbd_debug() in some places in ext4. It seems a bit strange to use jbd2 debugging output function for ext4 code. Also these days ext4_debug() uses dynamic printk so each debug message can be enabled / disabled on its own so the time when it made some sense to have these combined (to allow easier common selecting of messages to report) has passed. Just convert all jbd_debug() uses in ext4 to ext4_debug(). Signed-off-by: Jan Kara Reviewed-by: Lukas Czerner Link: https://lore.kernel.org/r/20220608112355.4397-1-jack@suse.cz Signed-off-by: Theodore Ts'o

ext4: fix null-ptr-deref in '__ext4_journal_ensure_credits'

2022-01-10T18:25:55+00:00

We got issue as follows when run syzkaller test: [ 1901.130043] EXT4-fs error (device vda): ext4_remount:5624: comm syz-executor.5: Abort forced by user [ 1901.130901] Aborting journal on device vda-8. [ 1901.131437] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.16: Detected aborted journal [ 1901.131566] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.11: Detected aborted journal [ 1901.132586] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.18: Detected aborted journal [ 1901.132751] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.9: Detected aborted journal [ 1901.136149] EXT4-fs error (device vda) in ext4_reserve_inode_write:6035: Journal has aborted [ 1901.136837] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-fuzzer: Detected aborted journal [ 1901.136915] ================================================================== [ 1901.138175] BUG: KASAN: null-ptr-deref in __ext4_journal_ensure_credits+0x74/0x140 [ext4] [ 1901.138343] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.13: Detected aborted journal [ 1901.138398] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.1: Detected aborted journal [ 1901.138808] Read of size 8 at addr 0000000000000000 by task syz-executor.17/968 [ 1901.138817] [ 1901.138852] EXT4-fs error (device vda): ext4_journal_check_start:61: comm syz-executor.30: Detected aborted journal [ 1901.144779] CPU: 1 PID: 968 Comm: syz-executor.17 Not tainted 4.19.90-vhulk2111.1.0.h893.eulerosv2r10.aarch64+ #1 [ 1901.146479] Hardware name: linux,dummy-virt (DT) [ 1901.147317] Call trace: [ 1901.147552] dump_backtrace+0x0/0x2d8 [ 1901.147898] show_stack+0x28/0x38 [ 1901.148215] dump_stack+0xec/0x15c [ 1901.148746] kasan_report+0x108/0x338 [ 1901.149207] __asan_load8+0x58/0xb0 [ 1901.149753] __ext4_journal_ensure_credits+0x74/0x140 [ext4] [ 1901.150579] ext4_xattr_delete_inode+0xe4/0x700 [ext4] [ 1901.151316] ext4_evict_inode+0x524/0xba8 [ext4] [ 1901.151985] evict+0x1a4/0x378 [ 1901.152353] iput+0x310/0x428 [ 1901.152733] do_unlinkat+0x260/0x428 [ 1901.153056] __arm64_sys_unlinkat+0x6c/0xc0 [ 1901.153455] el0_svc_common+0xc8/0x320 [ 1901.153799] el0_svc_handler+0xf8/0x160 [ 1901.154265] el0_svc+0x10/0x218 [ 1901.154682] ================================================================== This issue may happens like this: Process1 Process2 ext4_evict_inode ext4_journal_start ext4_truncate ext4_ind_truncate ext4_free_branches ext4_ind_truncate_ensure_credits ext4_journal_ensure_credits_fn ext4_journal_restart handle->h_transaction = NULL; mount -o remount,abort /mnt -> trigger JBD abort start_this_handle -> will return failed ext4_xattr_delete_inode ext4_journal_ensure_credits ext4_journal_ensure_credits_fn __ext4_journal_ensure_credits jbd2_handle_buffer_credits journal = handle->h_transaction->t_journal; ->null-ptr-deref Now, indirect truncate process didn't handle error. To solve this issue maybe simply add check handle is abort in '__ext4_journal_ensure_credits' is enough, and i also think this is necessary. Cc: stable@kernel.org Signed-off-by: Ye Bin Link: https://lore.kernel.org/r/20211224100341.3299128-1-yebin10@huawei.com Signed-off-by: Theodore Ts'o