BACKPORT: f2fs: fix potential deadloop in prepare_compress_overwrite()
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>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Bug: 446123564
Bug: 447304239
Change-Id: Ia4c06ed2b1542687cec57e84ec9acfc850443447
(cherry picked from commit 3147ee567dd9004a49826ddeaf0a4b12865d4409)
[Wei Zhang: Resolved page_folio(page) to page->index in fs/f2fs/compress.c]
Signed-off-by: Wei Zhang <wei265.zhang@tcl.corp-partner.google.com>
(cherry picked from commit 8adca69085bbe4a981b63905f9ef7e1e1608600e)
diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c
index 24550fe..cff0d45 100644
--- a/fs/f2fs/compress.c
+++ b/fs/f2fs/compress.c
@@ -1117,6 +1117,7 @@ static int prepare_compress_overwrite(struct compress_ctx *cc,
f2fs_compress_ctx_add_page(cc, page);
if (!PageUptodate(page)) {
+ f2fs_handle_page_eio(sbi, page->index, 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 261a543..ad5c102 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -2164,6 +2164,12 @@ 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 = bytes_to_blks(inode,
