| Message ID | 6ddf779148f44295acfbe547d9ec3aab@BJMBX02.spreadtrum.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [f2fs-dev] 答复: [PATCH v2 1/2] f2fs: fix to shrink read extent node in batches | expand |
On 2024/11/25 11:11, 王秀红 (Xiuhong Wang) wrote: > Hi Chao, > > after tested in this weekend with these patch base on the orginal case, no issue reproduced, so > Tested-by: Xiuhong Wang <xiuhong.wang@unisoc.com> Hi Xiuhong, Thanks for helping to test. Thanks, > > thanks! > > -----邮件原件----- > 发件人: Chao Yu <chao@kernel.org> > 发送时间: 2024年11月22日 14:50 > 收件人: jaegeuk@kernel.org > 抄送: linux-f2fs-devel@lists.sourceforge.net; linux-kernel@vger.kernel.org; Chao Yu <chao@kernel.org>; 王秀红 (Xiuhong Wang) <Xiuhong.Wang@unisoc.com>; 牛志国 (Zhiguo Niu) <Zhiguo.Niu@unisoc.com> > 主题: [PATCH v2 1/2] f2fs: fix to shrink read extent node in batches > > > 注意: 这封邮件来自于外部。除非你确定邮件内容安全，否则不要点击任何链接和附件。 > CAUTION: This email originated from outside of the organization. Do not click links or open attachments unless you recognize the sender and know the content is safe. > > > > We use rwlock to protect core structure data of extent tree during its shrink, however, if there is a huge number of extent nodes in extent tree, during shrink of extent tree, it may hold rwlock for a very long time, which may trigger kernel hang issue. > > This patch fixes to shrink read extent node in batches, so that, critical region of the rwlock can be shrunk to avoid its extreme long time hold. > > Reported-by: Xiuhong Wang <xiuhong.wang@unisoc.com> > Closes: https://lore.kernel.org/linux-f2fs-devel/20241112110627.1314632-1-xiuhong.wang@unisoc.com/ > Signed-off-by: Xiuhong Wang <xiuhong.wang@unisoc.com> > Signed-off-by: Zhiguo Niu <zhiguo.niu@unisoc.com> > Signed-off-by: Chao Yu <chao@kernel.org> > --- > v2: > - no updates. > fs/f2fs/extent_cache.c | 69 +++++++++++++++++++++++++----------------- > 1 file changed, 41 insertions(+), 28 deletions(-) > > diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c index 019c1f7b7fa5..b7a6817b44b0 100644 > --- a/fs/f2fs/extent_cache.c > +++ b/fs/f2fs/extent_cache.c > @@ -379,21 +379,22 @@ static struct extent_tree *__grab_extent_tree(struct inode *inode, } > > static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi, > - struct extent_tree *et) > + struct extent_tree *et, unsigned int > + nr_shrink) > { > struct rb_node *node, *next; > struct extent_node *en; > - unsigned int count = atomic_read(&et->node_cnt); > + unsigned int count; > > node = rb_first_cached(&et->root); > - while (node) { > + > + for (count = 0; node && count < nr_shrink; count++) { > next = rb_next(node); > en = rb_entry(node, struct extent_node, rb_node); > __release_extent_node(sbi, et, en); > node = next; > } > > - return count - atomic_read(&et->node_cnt); > + return count; > } > > static void __drop_largest_extent(struct extent_tree *et, @@ -622,6 +623,30 @@ static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi, > return en; > } > > +static unsigned int __destroy_extent_node(struct inode *inode, > + enum extent_type type) { > + struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > + struct extent_tree *et = F2FS_I(inode)->extent_tree[type]; > + unsigned int nr_shrink = type == EX_READ ? > + READ_EXTENT_CACHE_SHRINK_NUMBER : > + AGE_EXTENT_CACHE_SHRINK_NUMBER; > + unsigned int node_cnt = 0; > + > + if (!et || !atomic_read(&et->node_cnt)) > + return 0; > + > + while (atomic_read(&et->node_cnt)) { > + write_lock(&et->lock); > + node_cnt += __free_extent_tree(sbi, et, nr_shrink); > + write_unlock(&et->lock); > + } > + > + f2fs_bug_on(sbi, atomic_read(&et->node_cnt)); > + > + return node_cnt; > +} > + > static void __update_extent_tree_range(struct inode *inode, > struct extent_info *tei, enum extent_type type) { @@ -760,9 +785,6 @@ static void __update_extent_tree_range(struct inode *inode, > } > } > > - if (is_inode_flag_set(inode, FI_NO_EXTENT)) > - __free_extent_tree(sbi, et); > - > if (et->largest_updated) { > et->largest_updated = false; > updated = true; > @@ -780,6 +802,9 @@ static void __update_extent_tree_range(struct inode *inode, > out_read_extent_cache: > write_unlock(&et->lock); > > + if (is_inode_flag_set(inode, FI_NO_EXTENT)) > + __destroy_extent_node(inode, EX_READ); > + > if (updated) > f2fs_mark_inode_dirty_sync(inode, true); } @@ -942,10 +967,14 @@ static unsigned int __shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink > list_for_each_entry_safe(et, next, &eti->zombie_list, list) { > if (atomic_read(&et->node_cnt)) { > write_lock(&et->lock); > - node_cnt += __free_extent_tree(sbi, et); > + node_cnt += __free_extent_tree(sbi, et, > + nr_shrink - node_cnt - > + tree_cnt); > write_unlock(&et->lock); > } > - f2fs_bug_on(sbi, atomic_read(&et->node_cnt)); > + > + if (atomic_read(&et->node_cnt)) > + goto unlock_out; > + > list_del_init(&et->list); > radix_tree_delete(&eti->extent_tree_root, et->ino); > kmem_cache_free(extent_tree_slab, et); @@ -1084,23 +1113,6 @@ unsigned int f2fs_shrink_age_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink > return __shrink_extent_tree(sbi, nr_shrink, EX_BLOCK_AGE); } > > -static unsigned int __destroy_extent_node(struct inode *inode, > - enum extent_type type) > -{ > - struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > - struct extent_tree *et = F2FS_I(inode)->extent_tree[type]; > - unsigned int node_cnt = 0; > - > - if (!et || !atomic_read(&et->node_cnt)) > - return 0; > - > - write_lock(&et->lock); > - node_cnt = __free_extent_tree(sbi, et); > - write_unlock(&et->lock); > - > - return node_cnt; > -} > - > void f2fs_destroy_extent_node(struct inode *inode) { > __destroy_extent_node(inode, EX_READ); @@ -1109,7 +1121,6 @@ void f2fs_destroy_extent_node(struct inode *inode) > > static void __drop_extent_tree(struct inode *inode, enum extent_type type) { > - struct f2fs_sb_info *sbi = F2FS_I_SB(inode); > struct extent_tree *et = F2FS_I(inode)->extent_tree[type]; > bool updated = false; > > @@ -1117,7 +1128,6 @@ static void __drop_extent_tree(struct inode *inode, enum extent_type type) > return; > > write_lock(&et->lock); > - __free_extent_tree(sbi, et); > if (type == EX_READ) { > set_inode_flag(inode, FI_NO_EXTENT); > if (et->largest.len) { > @@ -1126,6 +1136,9 @@ static void __drop_extent_tree(struct inode *inode, enum extent_type type) > } > } > write_unlock(&et->lock); > + > + __destroy_extent_node(inode, type); > + > if (updated) > f2fs_mark_inode_dirty_sync(inode, true); } > -- > 2.40.1 >
diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c index 019c1f7b7fa5..b7a6817b44b0 100644 --- a/fs/f2fs/extent_cache.c +++ b/fs/f2fs/extent_cache.c @@ -379,21 +379,22 @@ static struct extent_tree *__grab_extent_tree(struct inode *inode, } static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi, - struct extent_tree *et) + struct extent_tree *et, unsigned int + nr_shrink) { struct rb_node *node, *next; struct extent_node *en; - unsigned int count = atomic_read(&et->node_cnt); + unsigned int count; node = rb_first_cached(&et->root); - while (node) { + + for (count = 0; node && count < nr_shrink; count++) { next = rb_next(node); en = rb_entry(node, struct extent_node, rb_node); __release_extent_node(sbi, et, en); node = next; } - return count - atomic_read(&et->node_cnt); + return count; } static void __drop_largest_extent(struct extent_tree *et, @@ -622,6 +623,30 @@ static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi, return en;