Messages in this thread Patch in this message | | | Date | Wed, 12 Sep 2018 13:03:32 -0700 | From | Jaegeuk Kim <> | Subject | Re: [PATCH v2] f2fs: submit cached bio to avoid endless PageWriteback |
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On 09/12, Chao Yu wrote: > 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@huawei.com> > --- > v2: > - cover node path suggested by Jaegeuk. > > fs/f2fs/f2fs.h | 4 ++- > fs/f2fs/gc.c | 72 +++++++++++++++++++++++++++++++++++--------------- > fs/f2fs/node.c | 14 +++++++--- > 3 files changed, 65 insertions(+), 25 deletions(-) > > diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h > index 8c8ce6b8f45a..da60e283ad1b 100644 > --- a/fs/f2fs/f2fs.h > +++ b/fs/f2fs/f2fs.h > @@ -523,6 +523,8 @@ enum { > */ > }; > > +#define WAIT_WRITEBACK 1 /* indicate page is set dirty in GC */ > + > #define DEFAULT_RETRY_IO_COUNT 8 /* maximum retry read IO count */ > > /* maximum retry quota flush count */ > @@ -2876,7 +2878,7 @@ 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..1ee287b7b94b 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) > + 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) > { > 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; > @@ -819,36 +830,46 @@ 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); > + > + err = WAIT_WRITEBACK;
Can we just return 0, and check like this?
if (f2fs_post_read_required(inode)) { 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) submitted++; }
> } else { > struct f2fs_io_info fio = { > .sbi = F2FS_I_SB(inode), > @@ -864,7 +885,6 @@ 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 +909,7 @@ static void move_data_page(struct inode *inode, block_t bidx, int gc_type, > } > out: > f2fs_put_page(page, 1); > + return err; > } > > /* > @@ -898,7 +919,7 @@ 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 +927,7 @@ 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 +944,7 @@ 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 +1016,7 @@ 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 +1036,15 @@ 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) > + submitted++; > + > if (locked) { > up_write(&fi->i_gc_rwsem[WRITE]); > up_write(&fi->i_gc_rwsem[READ]); > @@ -1030,6 +1056,8 @@ 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 +1085,7 @@ 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 +1129,11 @@ 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 +1144,7 @@ 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..5594765f4a71 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, > @@ -1597,22 +1599,28 @@ 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 */ > if (!PageWriteback(node_page)) > set_page_dirty(node_page); > + err = WAIT_WRITEBACK; > } > out_page: > 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.rc1
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