Re: [PATCH v3] f2fs: submit cached bio to avoid endless PageWriteback

From: Jaegeuk Kim
Date: Tue Sep 25 2018 - 21:42:26 EST


On 09/26, Chao Yu wrote:
> On 2018/9/26 8:20, Jaegeuk Kim wrote:
> > On 09/21, Chao Yu wrote:
> >> On 2018/9/18 10:14, Chao Yu wrote:
> >>> On 2018/9/18 10:02, Jaegeuk Kim wrote:
> >>>> On 09/18, Chao Yu wrote:
> >>>>> On 2018/9/18 9:37, Jaegeuk Kim wrote:
> >>>>>> On 09/18, Chao Yu wrote:
> >>>>>>> On 2018/9/18 9:04, Jaegeuk Kim wrote:
> >>>>>>>> On 09/13, Chao Yu wrote:
> >>>>>>>>> From: Chao Yu <yuchao0@xxxxxxxxxx>
> >>>>>>>>>
> >>>>>>>>> When migrating encrypted block from background GC thread, we only add
> >>>>>>>>> them into f2fs inner bio cache, but forget to submit the cached bio, it
> >>>>>>>>> may cause potential deadlock when we are waiting page writebacked, fix
> >>>>>>>>> it.
> >>>>>>>>>
> >>>>>>>>> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
> >>>>>>>>> ---
> >>>>>>>>> v3:
> >>>>>>>>> clean up codes suggested by Jaegeuk.
> >>>>>>>>> fs/f2fs/f2fs.h | 2 +-
> >>>>>>>>> fs/f2fs/gc.c | 71 +++++++++++++++++++++++++++++++++++---------------
> >>>>>>>>> fs/f2fs/node.c | 13 ++++++---
> >>>>>>>>> 3 files changed, 61 insertions(+), 25 deletions(-)
> >>>>>>>>>
> >>>>>>>>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> >>>>>>>>> index b676b82312e0..917b2ca76aac 100644
> >>>>>>>>> --- a/fs/f2fs/f2fs.h
> >>>>>>>>> +++ b/fs/f2fs/f2fs.h
> >>>>>>>>> @@ -2869,7 +2869,7 @@ struct page *f2fs_new_node_page(struct dnode_of_data *dn, unsigned int ofs);
> >>>>>>>>> void f2fs_ra_node_page(struct f2fs_sb_info *sbi, nid_t nid);
> >>>>>>>>> struct page *f2fs_get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid);
> >>>>>>>>> struct page *f2fs_get_node_page_ra(struct page *parent, int start);
> >>>>>>>>> -void f2fs_move_node_page(struct page *node_page, int gc_type);
> >>>>>>>>> +int f2fs_move_node_page(struct page *node_page, int gc_type);
> >>>>>>>>> int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
> >>>>>>>>> struct writeback_control *wbc, bool atomic,
> >>>>>>>>> unsigned int *seq_id);
> >>>>>>>>> diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
> >>>>>>>>> index a4c1a419611d..f57622cfe058 100644
> >>>>>>>>> --- a/fs/f2fs/gc.c
> >>>>>>>>> +++ b/fs/f2fs/gc.c
> >>>>>>>>> @@ -461,7 +461,7 @@ static int check_valid_map(struct f2fs_sb_info *sbi,
> >>>>>>>>> * On validity, copy that node with cold status, otherwise (invalid node)
> >>>>>>>>> * ignore that.
> >>>>>>>>> */
> >>>>>>>>> -static void gc_node_segment(struct f2fs_sb_info *sbi,
> >>>>>>>>> +static int gc_node_segment(struct f2fs_sb_info *sbi,
> >>>>>>>>> struct f2fs_summary *sum, unsigned int segno, int gc_type)
> >>>>>>>>> {
> >>>>>>>>> struct f2fs_summary *entry;
> >>>>>>>>> @@ -469,6 +469,7 @@ static void gc_node_segment(struct f2fs_sb_info *sbi,
> >>>>>>>>> int off;
> >>>>>>>>> int phase = 0;
> >>>>>>>>> bool fggc = (gc_type == FG_GC);
> >>>>>>>>> + int submitted = 0;
> >>>>>>>>>
> >>>>>>>>> start_addr = START_BLOCK(sbi, segno);
> >>>>>>>>>
> >>>>>>>>> @@ -482,10 +483,11 @@ static void gc_node_segment(struct f2fs_sb_info *sbi,
> >>>>>>>>> nid_t nid = le32_to_cpu(entry->nid);
> >>>>>>>>> struct page *node_page;
> >>>>>>>>> struct node_info ni;
> >>>>>>>>> + int err;
> >>>>>>>>>
> >>>>>>>>> /* stop BG_GC if there is not enough free sections. */
> >>>>>>>>> if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
> >>>>>>>>> - return;
> >>>>>>>>> + return submitted;
> >>>>>>>>>
> >>>>>>>>> if (check_valid_map(sbi, segno, off) == 0)
> >>>>>>>>> continue;
> >>>>>>>>> @@ -522,7 +524,9 @@ static void gc_node_segment(struct f2fs_sb_info *sbi,
> >>>>>>>>> continue;
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> - f2fs_move_node_page(node_page, gc_type);
> >>>>>>>>> + err = f2fs_move_node_page(node_page, gc_type);
> >>>>>>>>> + if (!err && gc_type == FG_GC)
> >>>>>>>>> + submitted++;
> >>>>>>>>> stat_inc_node_blk_count(sbi, 1, gc_type);
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> @@ -531,6 +535,7 @@ static void gc_node_segment(struct f2fs_sb_info *sbi,
> >>>>>>>>>
> >>>>>>>>> if (fggc)
> >>>>>>>>> atomic_dec(&sbi->wb_sync_req[NODE]);
> >>>>>>>>> + return submitted;
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> /*
> >>>>>>>>> @@ -666,7 +671,7 @@ static int ra_data_block(struct inode *inode, pgoff_t index)
> >>>>>>>>> * Move data block via META_MAPPING while keeping locked data page.
> >>>>>>>>> * This can be used to move blocks, aka LBAs, directly on disk.
> >>>>>>>>> */
> >>>>>>>>> -static void move_data_block(struct inode *inode, block_t bidx,
> >>>>>>>>> +static int move_data_block(struct inode *inode, block_t bidx,
> >>>>>>>>> int gc_type, unsigned int segno, int off)
> >>>>>>>>
> >>>>>>>> We don't need to submit IOs in this case.
> >>>>>>>
> >>>>>>> Actually, previously, we missed to submit IOs for encrypted block only in
> >>>>>>> BGGC, so we fix to submit for this case, all other codes are cleanups. Right?
> >>>>>>
> >>>>>> The move_data_block migrates encrypted blocks all the time with meta page IOs.
> >>>>>> I don't know what you're saying about BGGC.
> >>>>>
> >>>>> In move_data_block(), we use f2fs_submit_page_write() to add encrypted page
> >>>>> in to sbi->write_io[META].bio cache, so before exit GC, we need to submit
> >>>>> this cache by f2fs_submit_merged_write(), otherwise bio with encrypted page
> >>>>> will be cached in sbi->write_io[META].bio for long time, since we only
> >>>>> submmit this bio cache in foreground GC.
> >>>>>
> >>>>> if (gc_type == FG_GC)
> >>>>> f2fs_submit_merged_write(sbi,
> >>>>> (type == SUM_TYPE_NODE) ? NODE : DATA);
> >>>>
> >>>> Does this issue pending META IOs? I think META won't block any NODE/DATA
> >>>> pages. Moreover checkpoint or reading the moved block make the IOs be flushed,
> >>>> so it doesn't hurt the consistency.
> >>
> >> It may cause long latency before someone flushes the meta IO, how about flushing
> >> IO like other flows, like writepages?
> >>
> >> Or is there any benefit that we still cache meta IO after GC?
> >>
> >>>
> >>> I just guess below endless waiting for page writeback is cased by this case
> >>
> >> Any thoughts?
> >
> > I'm waiting for the previous reported issue. Do we have this in products?
>
> I didn't see such stack in products.
>
> BTW, I added one patch in my tree, although this patch is not correct now
> since it is missing to submit bio in some cases, it can easily reproduce
> such stack, so I guess there is still at least one place we didn't submit
> bio correctly.

How can we easily reproduce this? Why do we need to submit all of them?

>
> https://git.kernel.org/pub/scm/linux/kernel/git/chao/linux.git/commit/?h=f2fs-dev&id=2ca666658fc1958ab176030d435efa2ce325aa52
>
> Thanks,
>
> >
> >>
> >>>
> >>> -000|__switch_to()
> >>>
> >>> -001|__schedule()
> >>>
> >>> -002|need_resched(inline)
> >>>
> >>> -002|schedule()
> >>>
> >>> -003|schedule_timeout()
> >>>
> >>> -004|get_current(inline)
> >>>
> >>> -004|io_schedule_timeout()
> >>>
> >>> -005|bit_wait_io()
> >>>
> >>> -006|__wait_on_bit()
> >>>
> >>> -007|wait_on_page_bit()
> >>>
> >>> -008|PageWriteback(inline)
> >>>
> >>> -008|wait_on_page_writeback(inline)
> >>>
> >>> -008|__filemap_fdatawait_range()
> >>>
> >>> -009|filemap_fdatawait_keep_errors()
> >>>
> >>> -010|sync_inodes_sb()
> >>>
> >>> -011|__sync_filesystem(inline)
> >>>
> >>> -011|sync_filesystem()
> >>>
> >>> -012|generic_shutdown_super()
> >>>
> >>> -013|kill_block_super()
> >>>
> >>> -014|kill_f2fs_super()
> >>>
> >>> -015|deactivate_locked_super()
> >>>
> >>> -016|deactivate_super()
> >>>
> >>> -017|mnt_free_id(inline)
> >>>
> >>> -017|cleanup_mnt()
> >>>
> >>> -018|__cleanup_mnt()
> >>>
> >>> -019|task_work_run()
> >>>
> >>> -020|do_notify_resume()
> >>>
> >>> -021|work_pending(asm)
> >>>
> >>> -->|exception
> >>>
> >>> -022|NUX:0x539E58(asm)
> >>>
> >>> ---|end of frame
> >>>
> >>>>
> >>>>>
> >>>>>>
> >>>>>>>
> >>>>>>> Thanks,
> >>>>>>>
> >>>>>>>>
> >>>>>>>>> {
> >>>>>>>>> struct f2fs_io_info fio = {
> >>>>>>>>> @@ -685,25 +690,29 @@ static void move_data_block(struct inode *inode, block_t bidx,
> >>>>>>>>> struct node_info ni;
> >>>>>>>>> struct page *page, *mpage;
> >>>>>>>>> block_t newaddr;
> >>>>>>>>> - int err;
> >>>>>>>>> + int err = 0;
> >>>>>>>>> bool lfs_mode = test_opt(fio.sbi, LFS);
> >>>>>>>>>
> >>>>>>>>> /* do not read out */
> >>>>>>>>> page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
> >>>>>>>>> if (!page)
> >>>>>>>>> - return;
> >>>>>>>>> + return -ENOMEM;
> >>>>>>>>>
> >>>>>>>>> - if (!check_valid_map(F2FS_I_SB(inode), segno, off))
> >>>>>>>>> + if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
> >>>>>>>>> + err = -ENOENT;
> >>>>>>>>> goto out;
> >>>>>>>>> + }
> >>>>>>>>>
> >>>>>>>>> if (f2fs_is_atomic_file(inode)) {
> >>>>>>>>> F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
> >>>>>>>>> F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
> >>>>>>>>> + err = -EAGAIN;
> >>>>>>>>> goto out;
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> if (f2fs_is_pinned_file(inode)) {
> >>>>>>>>> f2fs_pin_file_control(inode, true);
> >>>>>>>>> + err = -EAGAIN;
> >>>>>>>>> goto out;
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> @@ -714,6 +723,7 @@ static void move_data_block(struct inode *inode, block_t bidx,
> >>>>>>>>>
> >>>>>>>>> if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
> >>>>>>>>> ClearPageUptodate(page);
> >>>>>>>>> + err = -ENOENT;
> >>>>>>>>> goto put_out;
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> @@ -796,6 +806,7 @@ static void move_data_block(struct inode *inode, block_t bidx,
> >>>>>>>>> fio.new_blkaddr = newaddr;
> >>>>>>>>> f2fs_submit_page_write(&fio);
> >>>>>>>>> if (fio.retry) {
> >>>>>>>>> + err = -EAGAIN;
> >>>>>>>>> if (PageWriteback(fio.encrypted_page))
> >>>>>>>>> end_page_writeback(fio.encrypted_page);
> >>>>>>>>> goto put_page_out;
> >>>>>>>>> @@ -819,34 +830,42 @@ static void move_data_block(struct inode *inode, block_t bidx,
> >>>>>>>>> f2fs_put_dnode(&dn);
> >>>>>>>>> out:
> >>>>>>>>> f2fs_put_page(page, 1);
> >>>>>>>>> + return err;
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> -static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
> >>>>>>>>> +static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
> >>>>>>>>> unsigned int segno, int off)
> >>>>>>>>> {
> >>>>>>>>> struct page *page;
> >>>>>>>>> + int err = 0;
> >>>>>>>>>
> >>>>>>>>> page = f2fs_get_lock_data_page(inode, bidx, true);
> >>>>>>>>> if (IS_ERR(page))
> >>>>>>>>> - return;
> >>>>>>>>> + return PTR_ERR(page);
> >>>>>>>>>
> >>>>>>>>> - if (!check_valid_map(F2FS_I_SB(inode), segno, off))
> >>>>>>>>> + if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
> >>>>>>>>> + err = -ENOENT;
> >>>>>>>>> goto out;
> >>>>>>>>> + }
> >>>>>>>>>
> >>>>>>>>> if (f2fs_is_atomic_file(inode)) {
> >>>>>>>>> F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
> >>>>>>>>> F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
> >>>>>>>>> + err = -EAGAIN;
> >>>>>>>>> goto out;
> >>>>>>>>> }
> >>>>>>>>> if (f2fs_is_pinned_file(inode)) {
> >>>>>>>>> if (gc_type == FG_GC)
> >>>>>>>>> f2fs_pin_file_control(inode, true);
> >>>>>>>>> + err = -EAGAIN;
> >>>>>>>>> goto out;
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> if (gc_type == BG_GC) {
> >>>>>>>>> - if (PageWriteback(page))
> >>>>>>>>> + if (PageWriteback(page)) {
> >>>>>>>>> + err = -EAGAIN;
> >>>>>>>>> goto out;
> >>>>>>>>> + }
> >>>>>>>>> set_page_dirty(page);
> >>>>>>>>> set_cold_data(page);
> >>>>>>>>> } else {
> >>>>>>>>> @@ -864,7 +883,6 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
> >>>>>>>>> .io_type = FS_GC_DATA_IO,
> >>>>>>>>> };
> >>>>>>>>> bool is_dirty = PageDirty(page);
> >>>>>>>>> - int err;
> >>>>>>>>>
> >>>>>>>>> retry:
> >>>>>>>>> set_page_dirty(page);
> >>>>>>>>> @@ -889,6 +907,7 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
> >>>>>>>>> }
> >>>>>>>>> out:
> >>>>>>>>> f2fs_put_page(page, 1);
> >>>>>>>>> + return err;
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> /*
> >>>>>>>>> @@ -898,7 +917,7 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
> >>>>>>>>> * If the parent node is not valid or the data block address is different,
> >>>>>>>>> * the victim data block is ignored.
> >>>>>>>>> */
> >>>>>>>>> -static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
> >>>>>>>>> +static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
> >>>>>>>>> struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
> >>>>>>>>> {
> >>>>>>>>> struct super_block *sb = sbi->sb;
> >>>>>>>>> @@ -906,6 +925,7 @@ static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
> >>>>>>>>> block_t start_addr;
> >>>>>>>>> int off;
> >>>>>>>>> int phase = 0;
> >>>>>>>>> + int submitted = 0;
> >>>>>>>>>
> >>>>>>>>> start_addr = START_BLOCK(sbi, segno);
> >>>>>>>>>
> >>>>>>>>> @@ -922,7 +942,7 @@ static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
> >>>>>>>>>
> >>>>>>>>> /* stop BG_GC if there is not enough free sections. */
> >>>>>>>>> if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
> >>>>>>>>> - return;
> >>>>>>>>> + return submitted;
> >>>>>>>>>
> >>>>>>>>> if (check_valid_map(sbi, segno, off) == 0)
> >>>>>>>>> continue;
> >>>>>>>>> @@ -994,6 +1014,7 @@ static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
> >>>>>>>>> if (inode) {
> >>>>>>>>> struct f2fs_inode_info *fi = F2FS_I(inode);
> >>>>>>>>> bool locked = false;
> >>>>>>>>> + int err;
> >>>>>>>>>
> >>>>>>>>> if (S_ISREG(inode->i_mode)) {
> >>>>>>>>> if (!down_write_trylock(&fi->i_gc_rwsem[READ]))
> >>>>>>>>> @@ -1013,12 +1034,16 @@ static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
> >>>>>>>>> start_bidx = f2fs_start_bidx_of_node(nofs, inode)
> >>>>>>>>> + ofs_in_node;
> >>>>>>>>> if (f2fs_post_read_required(inode))
> >>>>>>>>> - move_data_block(inode, start_bidx, gc_type,
> >>>>>>>>> - segno, off);
> >>>>>>>>> + err = move_data_block(inode, start_bidx,
> >>>>>>>>> + gc_type, segno, off);
> >>>>>>>>> else
> >>>>>>>>> - move_data_page(inode, start_bidx, gc_type,
> >>>>>>>>> + err = move_data_page(inode, start_bidx, gc_type,
> >>>>>>>>> segno, off);
> >>>>>>>>>
> >>>>>>>>> + if (!err && (gc_type == FG_GC ||
> >>>>>>>>> + f2fs_post_read_required(inode)))
> >>>>>>>>> + submitted++;
> >>>>>>>>> +
> >>>>>>>>> if (locked) {
> >>>>>>>>> up_write(&fi->i_gc_rwsem[WRITE]);
> >>>>>>>>> up_write(&fi->i_gc_rwsem[READ]);
> >>>>>>>>> @@ -1030,6 +1055,8 @@ static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
> >>>>>>>>>
> >>>>>>>>> if (++phase < 5)
> >>>>>>>>> goto next_step;
> >>>>>>>>> +
> >>>>>>>>> + return submitted;
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
> >>>>>>>>> @@ -1057,6 +1084,7 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
> >>>>>>>>> int seg_freed = 0;
> >>>>>>>>> unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
> >>>>>>>>> SUM_TYPE_DATA : SUM_TYPE_NODE;
> >>>>>>>>> + int submitted = 0;
> >>>>>>>>>
> >>>>>>>>> /* readahead multi ssa blocks those have contiguous address */
> >>>>>>>>> if (sbi->segs_per_sec > 1)
> >>>>>>>>> @@ -1100,10 +1128,11 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
> >>>>>>>>> * - lock_page(sum_page)
> >>>>>>>>> */
> >>>>>>>>> if (type == SUM_TYPE_NODE)
> >>>>>>>>> - gc_node_segment(sbi, sum->entries, segno, gc_type);
> >>>>>>>>> - else
> >>>>>>>>> - gc_data_segment(sbi, sum->entries, gc_list, segno,
> >>>>>>>>> + submitted += gc_node_segment(sbi, sum->entries, segno,
> >>>>>>>>> gc_type);
> >>>>>>>>> + else
> >>>>>>>>> + submitted += gc_data_segment(sbi, sum->entries, gc_list,
> >>>>>>>>> + segno, gc_type);
> >>>>>>>>>
> >>>>>>>>> stat_inc_seg_count(sbi, type, gc_type);
> >>>>>>>>>
> >>>>>>>>> @@ -1114,7 +1143,7 @@ static int do_garbage_collect(struct f2fs_sb_info *sbi,
> >>>>>>>>> f2fs_put_page(sum_page, 0);
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> - if (gc_type == FG_GC)
> >>>>>>>>> + if (submitted)
> >>>>>>>>> f2fs_submit_merged_write(sbi,
> >>>>>>>>> (type == SUM_TYPE_NODE) ? NODE : DATA);
> >>>>>>>>>
> >>>>>>>>> diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
> >>>>>>>>> index fa2381c0bc47..214dd6326b4b 100644
> >>>>>>>>> --- a/fs/f2fs/node.c
> >>>>>>>>> +++ b/fs/f2fs/node.c
> >>>>>>>>> @@ -1584,8 +1584,10 @@ static int __write_node_page(struct page *page, bool atomic, bool *submitted,
> >>>>>>>>> return AOP_WRITEPAGE_ACTIVATE;
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> -void f2fs_move_node_page(struct page *node_page, int gc_type)
> >>>>>>>>> +int f2fs_move_node_page(struct page *node_page, int gc_type)
> >>>>>>>>> {
> >>>>>>>>> + int err = 0;
> >>>>>>>>> +
> >>>>>>>>> if (gc_type == FG_GC) {
> >>>>>>>>> struct writeback_control wbc = {
> >>>>>>>>> .sync_mode = WB_SYNC_ALL,
> >>>>>>>>> @@ -1597,12 +1599,16 @@ void f2fs_move_node_page(struct page *node_page, int gc_type)
> >>>>>>>>> f2fs_wait_on_page_writeback(node_page, NODE, true);
> >>>>>>>>>
> >>>>>>>>> f2fs_bug_on(F2FS_P_SB(node_page), PageWriteback(node_page));
> >>>>>>>>> - if (!clear_page_dirty_for_io(node_page))
> >>>>>>>>> + if (!clear_page_dirty_for_io(node_page)) {
> >>>>>>>>> + err = -EAGAIN;
> >>>>>>>>> goto out_page;
> >>>>>>>>> + }
> >>>>>>>>>
> >>>>>>>>> if (__write_node_page(node_page, false, NULL,
> >>>>>>>>> - &wbc, false, FS_GC_NODE_IO, NULL))
> >>>>>>>>> + &wbc, false, FS_GC_NODE_IO, NULL)) {
> >>>>>>>>> + err = -EAGAIN;
> >>>>>>>>> unlock_page(node_page);
> >>>>>>>>> + }
> >>>>>>>>> goto release_page;
> >>>>>>>>> } else {
> >>>>>>>>> /* set page dirty and write it */
> >>>>>>>>> @@ -1613,6 +1619,7 @@ void f2fs_move_node_page(struct page *node_page, int gc_type)
> >>>>>>>>> unlock_page(node_page);
> >>>>>>>>> release_page:
> >>>>>>>>> f2fs_put_page(node_page, 0);
> >>>>>>>>> + return err;
> >>>>>>>>> }
> >>>>>>>>>
> >>>>>>>>> static int f2fs_write_node_page(struct page *page,
> >>>>>>>>> --
> >>>>>>>>> 2.18.0
> >>>>>>>>
> >>>>>>>> .
> >>>>>>>>
> >>>>>>
> >>>>>> .
> >>>>>>
> >>>>
> >>>> .
> >>>>
> >>>
> >
> > .
> >