| Message ID | 20250303032329.1309786-1-chao@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 3147ee567dd9004a49826ddeaf0a4b12865d4409 |
| Headers | show |
| Series | [f2fs-dev] f2fs: fix potential deadloop in prepare_compress_overwrite() | expand |
Hello: This patch was applied to jaegeuk/f2fs.git (dev) by Jaegeuk Kim <jaegeuk@kernel.org>: On Mon, 3 Mar 2025 11:23:29 +0800 you wrote: > Jan Prusakowski reported a kernel hang issue as below: > > When running xfstests on linux-next kernel (6.14.0-rc3, 6.12) I > encountered a problem in generic/475 test where fsstress process > gets blocked in __f2fs_write_data_pages() and the test hangs. > The options I used are: > > [...] Here is the summary with links: - [f2fs-dev] f2fs: fix potential deadloop in prepare_compress_overwrite() https://git.kernel.org/jaegeuk/f2fs/c/3147ee567dd9 You are awesome, thank you!
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c index 985690d81a82..9b94810675c1 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -1150,6 +1150,7 @@ static int prepare_compress_overwrite(struct compress_ctx *cc, f2fs_compress_ctx_add_page(cc, page_folio(page)); if (!PageUptodate(page)) { + f2fs_handle_page_eio(sbi, page_folio(page), DATA); release_and_retry: f2fs_put_rpages(cc); f2fs_unlock_rpages(cc, i + 1); diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index f1554a5a3d7a..09437dbd1b42 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -2190,6 +2190,12 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, int i; int ret = 0; + if (unlikely(f2fs_cp_error(sbi))) { + ret = -EIO; + from_dnode = false; + goto out_put_dnode; + } + f2fs_bug_on(sbi, f2fs_cluster_is_empty(cc)); last_block_in_file = F2FS_BYTES_TO_BLK(f2fs_readpage_limit(inode) + @@ -2233,10 +2239,6 @@ int f2fs_read_multi_pages(struct compress_ctx *cc, struct bio **bio_ret, if (ret) goto out; - if (unlikely(f2fs_cp_error(sbi))) { - ret = -EIO; - goto out_put_dnode; - } f2fs_bug_on(sbi, dn.data_blkaddr != COMPRESS_ADDR); skip_reading_dnode:
Jan Prusakowski reported a kernel hang issue as below: When running xfstests on linux-next kernel (6.14.0-rc3, 6.12) I encountered a problem in generic/475 test where fsstress process gets blocked in __f2fs_write_data_pages() and the test hangs. The options I used are: MKFS_OPTIONS -- -O compression -O extra_attr -O project_quota -O quota /dev/vdc MOUNT_OPTIONS -- -o acl,user_xattr -o discard,compress_extension=* /dev/vdc /vdc INFO: task kworker/u8:0:11 blocked for more than 122 seconds. Not tainted 6.14.0-rc3-xfstests-lockdep #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:0 state:D stack:0 pid:11 tgid:11 ppid:2 task_flags:0x4208160 flags:0x00004000 Workqueue: writeback wb_workfn (flush-253:0) Call Trace: <TASK> __schedule+0x309/0x8e0 schedule+0x3a/0x100 schedule_preempt_disabled+0x15/0x30 __mutex_lock+0x59a/0xdb0 __f2fs_write_data_pages+0x3ac/0x400 do_writepages+0xe8/0x290 __writeback_single_inode+0x5c/0x360 writeback_sb_inodes+0x22f/0x570 wb_writeback+0xb0/0x410 wb_do_writeback+0x47/0x2f0 wb_workfn+0x5a/0x1c0 process_one_work+0x223/0x5b0 worker_thread+0x1d5/0x3c0 kthread+0xfd/0x230 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x1a/0x30 </TASK> The root cause is: once generic/475 starts toload error table to dm device, f2fs_prepare_compress_overwrite() will loop reading compressed cluster pages due to IO error, meanwhile it has held .writepages lock, it can block all other writeback tasks. Let's fix this issue w/ below changes: - add f2fs_handle_page_eio() in prepare_compress_overwrite() to detect IO error. - detect cp_error earler in f2fs_read_multi_pages(). Fixes: 4c8ff7095bef ("f2fs: support data compression") Reported-by: Jan Prusakowski <jprusakowski@google.com> Signed-off-by: Chao Yu <chao@kernel.org> --- fs/f2fs/compress.c | 1 + fs/f2fs/data.c | 10 ++++++---- 2 files changed, 7 insertions(+), 4 deletions(-)