Otherwise, f2fs can break the the consistency.
(e.g., BUG_ON in f2fs_get_sum_page)
Then, this reveals another issue where we go into an infinite loop on normal
error case. It turns out we abused f2fs_get_meta_page_nofail() in this path.
- f2fs_fill_super
- f2fs_build_segment_manager
- build_sit_entries
- get_current_sit_page
Actually, we didn't have to use _nofail in this case, since we could return
error to mount(2) already with the error handler.
This was caught by syzbot as follows.
INFO: task syz-executor178:6870 can't die for more than 143 seconds.
task:syz-executor178 state:R
stack:26960 pid: 6870 ppid: 6869 flags:0x00004006
Call Trace:
Showing all locks held in the system:
1 lock held by khungtaskd/1179:
#0: ffffffff8a554da0 (rcu_read_lock){....}-{1:2}, at:
debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6242
1 lock held by systemd-journal/3920:
1 lock held by in:imklog/6769:
#0: ffff88809eebc130 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100
fs/file.c:930
1 lock held by syz-executor178/6870:
#0: ffff8880925120e0 (&type->s_umount_key#47/1){+.+.}-{3:3}, at:
alloc_super+0x201/0xaf0 fs/super.c:229
Reported-by: syzbot+ee250ac8137be41d7...@syzkaller.appspotmail.com
Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
---
v2 log:
- fix syzbot issue
fs/f2fs/checkpoint.c | 9 +++------
fs/f2fs/f2fs.h | 2 --
fs/f2fs/segment.c | 2 +-
3 files changed, 4 insertions(+), 9 deletions(-)
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c
index f18386d30f031..7bb3a741a8f16 100644
--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -110,15 +110,12 @@ struct page *f2fs_get_meta_page(struct f2fs_sb_info *sbi,
pgoff_t index)
struct page *f2fs_get_meta_page_nofail(struct f2fs_sb_info *sbi, pgoff_t index)
{
struct page *page;
- int count = 0;
-
retry:
page = __get_meta_page(sbi, index, true);
if (IS_ERR(page)) {
- if (PTR_ERR(page) == -EIO &&
- ++count <= DEFAULT_RETRY_IO_COUNT)
- goto retry;
- f2fs_stop_checkpoint(sbi, false);
+ f2fs_flush_merged_writes(sbi);
+ congestion_wait(BLK_RW_ASYNC, DEFAULT_IO_TIMEOUT);
+ goto retry;
}
return page;
}
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index ae46d44bd5211..ce79b9b5b1eff 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -593,8 +593,6 @@ enum {
*/
};
-#define DEFAULT_RETRY_IO_COUNT 8 /* maximum retry read IO count */
-
/* congestion wait timeout value, default: 20ms */
#define DEFAULT_IO_TIMEOUT (msecs_to_jiffies(20))
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 13ecd2c2c361b..40001d80fa86d 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3964,7 +3964,7 @@ int f2fs_lookup_journal_in_cursum(struct f2fs_journal
*journal, int type,
static struct page *get_current_sit_page(struct f2fs_sb_info *sbi,
unsigned int segno)
{
- return f2fs_get_meta_page_nofail(sbi, current_sit_addr(sbi, segno));
+ return f2fs_get_meta_page(sbi, current_sit_addr(sbi, segno));
}
static struct page *get_next_sit_page(struct f2fs_sb_info *sbi,
--
2.28.0.1011.ga647a8990f-goog
