From: Sahitya Tummala stummala@codeaurora.org
[ Upstream commit bf22c3cc8ce71454dddd772284773306a68031d8 ]
There could be a scenario where f2fs_sync_meta_pages() will not ensure that all F2FS_DIRTY_META pages are submitted for IO. Thus, resulting in the below panic in do_checkpoint() -
f2fs_bug_on(sbi, get_pages(sbi, F2FS_DIRTY_META) && !f2fs_cp_error(sbi));
This can happen in a low-memory condition, where shrinker could also be doing the writepage operation (stack shown below) at the same time when checkpoint is running on another core.
schedule down_write f2fs_submit_page_write -> by this time, this page in page cache is tagged as PAGECACHE_TAG_WRITEBACK and PAGECACHE_TAG_DIRTY is cleared, due to which f2fs_sync_meta_pages() cannot sync this page in do_checkpoint() path. f2fs_do_write_meta_page __f2fs_write_meta_page f2fs_write_meta_page shrink_page_list shrink_inactive_list shrink_node_memcg shrink_node kswapd
Signed-off-by: Sahitya Tummala stummala@codeaurora.org Reviewed-by: Chao Yu yuchao0@huawei.com Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- fs/f2fs/checkpoint.c | 16 +++++++--------- fs/f2fs/f2fs.h | 2 +- fs/f2fs/super.c | 2 +- 3 files changed, 9 insertions(+), 11 deletions(-)
diff --git a/fs/f2fs/checkpoint.c b/fs/f2fs/checkpoint.c index ffdaba0c55d29..fc33fdb31c75d 100644 --- a/fs/f2fs/checkpoint.c +++ b/fs/f2fs/checkpoint.c @@ -1250,20 +1250,20 @@ static void unblock_operations(struct f2fs_sb_info *sbi) f2fs_unlock_all(sbi); }
-void f2fs_wait_on_all_pages_writeback(struct f2fs_sb_info *sbi) +void f2fs_wait_on_all_pages(struct f2fs_sb_info *sbi, int type) { DEFINE_WAIT(wait);
for (;;) { prepare_to_wait(&sbi->cp_wait, &wait, TASK_UNINTERRUPTIBLE);
- if (!get_pages(sbi, F2FS_WB_CP_DATA)) + if (!get_pages(sbi, type)) break;
if (unlikely(f2fs_cp_error(sbi))) break;
- io_schedule_timeout(5*HZ); + io_schedule_timeout(HZ/50); } finish_wait(&sbi->cp_wait, &wait); } @@ -1384,8 +1384,6 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
/* Flush all the NAT/SIT pages */ f2fs_sync_meta_pages(sbi, META, LONG_MAX, FS_CP_META_IO); - f2fs_bug_on(sbi, get_pages(sbi, F2FS_DIRTY_META) && - !f2fs_cp_error(sbi));
/* * modify checkpoint @@ -1493,11 +1491,11 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
/* Here, we have one bio having CP pack except cp pack 2 page */ f2fs_sync_meta_pages(sbi, META, LONG_MAX, FS_CP_META_IO); - f2fs_bug_on(sbi, get_pages(sbi, F2FS_DIRTY_META) && - !f2fs_cp_error(sbi)); + /* Wait for all dirty meta pages to be submitted for IO */ + f2fs_wait_on_all_pages(sbi, F2FS_DIRTY_META);
/* wait for previous submitted meta pages writeback */ - f2fs_wait_on_all_pages_writeback(sbi); + f2fs_wait_on_all_pages(sbi, F2FS_WB_CP_DATA);
/* flush all device cache */ err = f2fs_flush_device_cache(sbi); @@ -1506,7 +1504,7 @@ static int do_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc)
/* barrier and flush checkpoint cp pack 2 page if it can */ commit_checkpoint(sbi, ckpt, start_blk); - f2fs_wait_on_all_pages_writeback(sbi); + f2fs_wait_on_all_pages(sbi, F2FS_WB_CP_DATA);
/* * invalidate intermediate page cache borrowed from meta inode diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 5a888a063c7f1..b0e0535f7f56a 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -3196,7 +3196,7 @@ int f2fs_get_valid_checkpoint(struct f2fs_sb_info *sbi); void f2fs_update_dirty_page(struct inode *inode, struct page *page); void f2fs_remove_dirty_inode(struct inode *inode); int f2fs_sync_dirty_inodes(struct f2fs_sb_info *sbi, enum inode_type type); -void f2fs_wait_on_all_pages_writeback(struct f2fs_sb_info *sbi); +void f2fs_wait_on_all_pages(struct f2fs_sb_info *sbi, int type); int f2fs_write_checkpoint(struct f2fs_sb_info *sbi, struct cp_control *cpc); void f2fs_init_ino_entry_info(struct f2fs_sb_info *sbi); int __init f2fs_create_checkpoint_caches(void); diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index ac01c3f8863d9..a0a2f46f450dc 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -1105,7 +1105,7 @@ static void f2fs_put_super(struct super_block *sb) /* our cp_error case, we can wait for any writeback page */ f2fs_flush_merged_writes(sbi);
- f2fs_wait_on_all_pages_writeback(sbi); + f2fs_wait_on_all_pages(sbi, F2FS_WB_CP_DATA);
f2fs_bug_on(sbi, sbi->fsync_node_num);