[PATCH AUTOSEL for 4.14 058/161] f2fs: avoid hungtask when GC encrypted block if io_bits is set

Sasha Levin
2018-04-09T03:17:50Z

From: Sheng Yong <shengyong1@huawei.com>

[ Upstream commit a9d572c7550044d5b217b5287d99a2e6d34b97b0 ]

When io_bits is set, GCing encrypted block may hit the following hungtask.
Since io_bits requires aligned block address, f2fs_submit_page_write may
return -EAGAIN if new_blkaddr does not satisify io_bits alignment. As a
result, the encrypted page will never be writtenback.

This patch makes move_data_block aware the EAGAIN error and cancel the
writeback.

[ 246.751371] INFO: task kworker/u4:4:797 blocked for more than 90 seconds.
[ 246.752423] Not tainted 4.15.0-rc4+ #11
[ 246.754176] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 246.755336] kworker/u4:4 D25448 797 2 0x80000000
[ 246.755597] Workqueue: writeback wb_workfn (flush-7:0)
[ 246.755616] Call Trace:
[ 246.755695] ? __schedule+0x322/0xa90
[ 246.755761] ? blk_init_request_from_bio+0x120/0x120
[ 246.755773] ? pci_mmcfg_check_reserved+0xb0/0xb0
[ 246.755801] ? __radix_tree_create+0x19e/0x200
[ 246.755813] ? delete_node+0x136/0x370
[ 246.755838] schedule+0x43/0xc0
[ 246.755904] io_schedule+0x17/0x40
[ 246.755939] wait_on_page_bit_common+0x17b/0x240
[ 246.755950] ? wake_page_function+0xa0/0xa0
[ 246.755961] ? add_to_page_cache_lru+0x160/0x160
[ 246.755972] ? page_cache_tree_insert+0x170/0x170
[ 246.755983] ? __lru_cache_add+0x96/0xb0
[ 246.756086] __filemap_fdatawait_range+0x14f/0x1c0
[ 246.756097] ? wait_on_page_bit_common+0x240/0x240
[ 246.756120] ? __wake_up_locked_key_bookmark+0x20/0x20
[ 246.756167] ? wait_on_all_pages_writeback+0xc9/0x100
[ 246.756179] ? __remove_ino_entry+0x120/0x120
[ 246.756192] ? wait_woken+0x100/0x100
[ 246.756204] filemap_fdatawait_range+0x9/0x20
[ 246.756216] write_checkpoint+0x18a1/0x1f00
[ 246.756254] ? blk_get_request+0x10/0x10
[ 246.756265] ? cpumask_next_and+0x43/0x60
[ 246.756279] ? f2fs_sync_inode_meta+0x160/0x160
[ 246.756289] ? remove_element.isra.4+0xa0/0xa0
[ 246.756300] ? __put_compound_page+0x40/0x40
[ 246.756310] ? f2fs_sync_fs+0xec/0x1c0
[ 246.756320] ? f2fs_sync_fs+0x120/0x1c0
[ 246.756329] f2fs_sync_fs+0x120/0x1c0
[ 246.756357] ? trace_event_raw_event_f2fs__page+0x260/0x260
[ 246.756393] ? ata_build_rw_tf+0x173/0x410
[ 246.756397] f2fs_balance_fs_bg+0x198/0x390
[ 246.756405] ? drop_inmem_page+0x230/0x230
[ 246.756415] ? ahci_qc_prep+0x1bb/0x2e0
[ 246.756418] ? ahci_qc_issue+0x1df/0x290
[ 246.756422] ? __accumulate_pelt_segments+0x42/0xd0
[ 246.756426] ? f2fs_write_node_pages+0xd1/0x380
[ 246.756429] f2fs_write_node_pages+0xd1/0x380
[ 246.756437] ? sync_node_pages+0x8f0/0x8f0
[ 246.756440] ? update_curr+0x53/0x220
[ 246.756444] ? __accumulate_pelt_segments+0xa2/0xd0
[ 246.756448] ? __update_load_avg_se.isra.39+0x349/0x360
[ 246.756452] ? do_writepages+0x2a/0xa0
[ 246.756456] do_writepages+0x2a/0xa0
[ 246.756460] __writeback_single_inode+0x70/0x490
[ 246.756463] ? check_preempt_wakeup+0x199/0x310
[ 246.756467] writeback_sb_inodes+0x2a2/0x660
[ 246.756471] ? is_empty_dir_inode+0x40/0x40
[ 246.756474] ? __writeback_single_inode+0x490/0x490
[ 246.756477] ? string+0xbf/0xf0
[ 246.756480] ? down_read_trylock+0x35/0x60
[ 246.756484] __writeback_inodes_wb+0x9f/0xf0
[ 246.756488] wb_writeback+0x41d/0x4b0
[ 246.756492] ? writeback_inodes_wb.constprop.55+0x150/0x150
[ 246.756498] ? set_worker_desc+0xf7/0x130
[ 246.756502] ? current_is_workqueue_rescuer+0x60/0x60
[ 246.756511] ? _find_next_bit+0x2c/0xa0
[ 246.756514] ? wb_workfn+0x400/0x5d0
[ 246.756518] wb_workfn+0x400/0x5d0
[ 246.756521] ? finish_task_switch+0xdf/0x2a0
[ 246.756525] ? inode_wait_for_writeback+0x30/0x30
[ 246.756529] process_one_work+0x3a7/0x6f0
[ 246.756533] worker_thread+0x82/0x750
[ 246.756537] kthread+0x16f/0x1c0
[ 246.756541] ? trace_event_raw_event_workqueue_work+0x110/0x110
[ 246.756544] ? kthread_create_worker_on_cpu+0xb0/0xb0
[ 246.756548] ret_from_fork+0x1f/0x30

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
---
fs/f2fs/gc.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
index bfe6a8ccc3a0..7fb2729d8ee0 100644
--- a/fs/f2fs/gc.c
+++ b/fs/f2fs/gc.c
@@ -695,7 +695,12 @@ static void move_data_block(struct inode *inode, block_t bidx,
fio.op = REQ_OP_WRITE;
fio.op_flags = REQ_SYNC;
fio.new_blkaddr = newaddr;
- f2fs_submit_page_write(&fio);
+ err = f2fs_submit_page_write(&fio);
+ if (err) {
+ if (PageWriteback(fio.encrypted_page))
+ end_page_writeback(fio.encrypted_page);
+ goto put_page_out;
+ }

f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);

--
2.15.1