From: Chao Yu <chao@kernel.org>
To: Zhikang Zhang <zhangzhikang1@huawei.com>,
jaegeuk@kernel.org, yuchao0@huawei.com
Cc: miaoxie@huawei.com, linux-f2fs-devel@lists.sourceforge.net
Subject: Re: [PATCH v3] f2fs: avoid sleeping under spin_lock
Date: Mon, 10 Sep 2018 22:34:58 +0800 [thread overview]
Message-ID: <90a59906-e849-2adf-bbf8-0241dc5e1377@kernel.org> (raw)
In-Reply-To: <1536567505-5755-1-git-send-email-zhangzhikang1@huawei.com>
On 2018/9/10 16:18, Zhikang Zhang wrote:
> In the call trace below, we might sleep in function dput().
>
> So in order to avoid sleeping under spin_lock, we remove f2fs_mark_inode_dirty_sync
> from __try_update_largest_extent && __drop_largest_extent.
>
> BUG: sleeping function called from invalid context at fs/dcache.c:796
> Call trace:
> dump_backtrace+0x0/0x3f4
> show_stack+0x24/0x30
> dump_stack+0xe0/0x138
> ___might_sleep+0x2a8/0x2c8
> __might_sleep+0x78/0x10c
> dput+0x7c/0x750
> block_dump___mark_inode_dirty+0x120/0x17c
> __mark_inode_dirty+0x344/0x11f0
> f2fs_mark_inode_dirty_sync+0x40/0x50
> __insert_extent_tree+0x2e0/0x2f4
> f2fs_update_extent_tree_range+0xcf4/0xde8
> f2fs_update_extent_cache+0x114/0x12c
> f2fs_update_data_blkaddr+0x40/0x50
> write_data_page+0x150/0x314
> do_write_data_page+0x648/0x2318
> __write_data_page+0xdb4/0x1640
> f2fs_write_cache_pages+0x768/0xafc
> __f2fs_write_data_pages+0x590/0x1218
> f2fs_write_data_pages+0x64/0x74
> do_writepages+0x74/0xe4
> __writeback_single_inode+0xdc/0x15f0
> writeback_sb_inodes+0x574/0xc98
> __writeback_inodes_wb+0x190/0x204
> wb_writeback+0x730/0xf14
> wb_check_old_data_flush+0x1bc/0x1c8
> wb_workfn+0x554/0xf74
> process_one_work+0x440/0x118c
> worker_thread+0xac/0x974
> kthread+0x1a0/0x1c8
> ret_from_fork+0x10/0x1c
Missed a Signed-off-by here?
Signed-off-by: Zhikang Zhang <zhangzhikang1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
I think Jaegeuk can help to add them when merging this patch. :)
Thanks,
> ---
> fs/f2fs/extent_cache.c | 51 +++++++++++++++++++++++++++++++-------------------
> fs/f2fs/f2fs.h | 7 ++++---
> 2 files changed, 36 insertions(+), 22 deletions(-)
>
> diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
> index 231b77e..a70cd25 100644
> --- a/fs/f2fs/extent_cache.c
> +++ b/fs/f2fs/extent_cache.c
> @@ -308,14 +308,13 @@ static unsigned int __free_extent_tree(struct f2fs_sb_info *sbi,
> return count - atomic_read(&et->node_cnt);
> }
>
> -static void __drop_largest_extent(struct inode *inode,
> +static void __drop_largest_extent(struct extent_tree *et,
> pgoff_t fofs, unsigned int len)
> {
> - struct extent_info *largest = &F2FS_I(inode)->extent_tree->largest;
> -
> - if (fofs < largest->fofs + largest->len && fofs + len > largest->fofs) {
> - largest->len = 0;
> - f2fs_mark_inode_dirty_sync(inode, true);
> + if (fofs < et->largest.fofs + et->largest.len &&
> + fofs + len > et->largest.fofs) {
> + et->largest.len = 0;
> + et->largest_updated = true;
> }
> }
>
> @@ -416,12 +415,11 @@ static bool f2fs_lookup_extent_tree(struct inode *inode, pgoff_t pgofs,
> return ret;
> }
>
> -static struct extent_node *__try_merge_extent_node(struct inode *inode,
> +static struct extent_node *__try_merge_extent_node(struct f2fs_sb_info *sbi,
> struct extent_tree *et, struct extent_info *ei,
> struct extent_node *prev_ex,
> struct extent_node *next_ex)
> {
> - struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> struct extent_node *en = NULL;
>
> if (prev_ex && __is_back_mergeable(ei, &prev_ex->ei)) {
> @@ -443,7 +441,7 @@ static struct extent_node *__try_merge_extent_node(struct inode *inode,
> if (!en)
> return NULL;
>
> - __try_update_largest_extent(inode, et, en);
> + __try_update_largest_extent(et, en);
>
> spin_lock(&sbi->extent_lock);
> if (!list_empty(&en->list)) {
> @@ -454,12 +452,11 @@ static struct extent_node *__try_merge_extent_node(struct inode *inode,
> return en;
> }
>
> -static struct extent_node *__insert_extent_tree(struct inode *inode,
> +static struct extent_node *__insert_extent_tree(struct f2fs_sb_info *sbi,
> struct extent_tree *et, struct extent_info *ei,
> struct rb_node **insert_p,
> struct rb_node *insert_parent)
> {
> - struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> struct rb_node **p;
> struct rb_node *parent = NULL;
> struct extent_node *en = NULL;
> @@ -476,7 +473,7 @@ static struct extent_node *__insert_extent_tree(struct inode *inode,
> if (!en)
> return NULL;
>
> - __try_update_largest_extent(inode, et, en);
> + __try_update_largest_extent(et, en);
>
> /* update in global extent list */
> spin_lock(&sbi->extent_lock);
> @@ -497,6 +494,7 @@ static void f2fs_update_extent_tree_range(struct inode *inode,
> struct rb_node **insert_p = NULL, *insert_parent = NULL;
> unsigned int end = fofs + len;
> unsigned int pos = (unsigned int)fofs;
> + bool updated = false;
>
> if (!et)
> return;
> @@ -517,7 +515,7 @@ static void f2fs_update_extent_tree_range(struct inode *inode,
> * drop largest extent before lookup, in case it's already
> * been shrunk from extent tree
> */
> - __drop_largest_extent(inode, fofs, len);
> + __drop_largest_extent(et, fofs, len);
>
> /* 1. lookup first extent node in range [fofs, fofs + len - 1] */
> en = (struct extent_node *)f2fs_lookup_rb_tree_ret(&et->root,
> @@ -550,7 +548,7 @@ static void f2fs_update_extent_tree_range(struct inode *inode,
> set_extent_info(&ei, end,
> end - dei.fofs + dei.blk,
> org_end - end);
> - en1 = __insert_extent_tree(inode, et, &ei,
> + en1 = __insert_extent_tree(sbi, et, &ei,
> NULL, NULL);
> next_en = en1;
> } else {
> @@ -570,7 +568,7 @@ static void f2fs_update_extent_tree_range(struct inode *inode,
> }
>
> if (parts)
> - __try_update_largest_extent(inode, et, en);
> + __try_update_largest_extent(et, en);
> else
> __release_extent_node(sbi, et, en);
>
> @@ -590,15 +588,16 @@ static void f2fs_update_extent_tree_range(struct inode *inode,
> if (blkaddr) {
>
> set_extent_info(&ei, fofs, blkaddr, len);
> - if (!__try_merge_extent_node(inode, et, &ei, prev_en, next_en))
> - __insert_extent_tree(inode, et, &ei,
> + if (!__try_merge_extent_node(sbi, et, &ei, prev_en, next_en))
> + __insert_extent_tree(sbi, et, &ei,
> insert_p, insert_parent);
>
> /* give up extent_cache, if split and small updates happen */
> if (dei.len >= 1 &&
> prev.len < F2FS_MIN_EXTENT_LEN &&
> et->largest.len < F2FS_MIN_EXTENT_LEN) {
> - __drop_largest_extent(inode, 0, UINT_MAX);
> + et->largest.len = 0;
> + et->largest_updated = true;
> set_inode_flag(inode, FI_NO_EXTENT);
> }
> }
> @@ -606,7 +605,15 @@ static void f2fs_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;
> + }
> +
> write_unlock(&et->lock);
> +
> + if (updated)
> + f2fs_mark_inode_dirty_sync(inode, true);
> }
>
> unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink)
> @@ -705,6 +712,7 @@ void f2fs_drop_extent_tree(struct inode *inode)
> {
> struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
> struct extent_tree *et = F2FS_I(inode)->extent_tree;
> + bool updated = false;
>
> if (!f2fs_may_extent_tree(inode))
> return;
> @@ -713,8 +721,13 @@ void f2fs_drop_extent_tree(struct inode *inode)
>
> write_lock(&et->lock);
> __free_extent_tree(sbi, et);
> - __drop_largest_extent(inode, 0, UINT_MAX);
> + if (et->largest.len) {
> + et->largest.len = 0;
> + updated = true;
> + }
> write_unlock(&et->lock);
> + if (updated)
> + f2fs_mark_inode_dirty_sync(inode, true);
> }
>
> void f2fs_destroy_extent_tree(struct inode *inode)
> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
> index abf9256..e146e6c 100644
> --- a/fs/f2fs/f2fs.h
> +++ b/fs/f2fs/f2fs.h
> @@ -572,6 +572,7 @@ struct extent_tree {
> struct list_head list; /* to be used by sbi->zombie_list */
> rwlock_t lock; /* protect extent info rb-tree */
> atomic_t node_cnt; /* # of extent node in rb-tree*/
> + bool largest_updated; /* largest extent updated */
> };
>
> /*
> @@ -754,12 +755,12 @@ static inline bool __is_front_mergeable(struct extent_info *cur,
> }
>
> extern void f2fs_mark_inode_dirty_sync(struct inode *inode, bool sync);
> -static inline void __try_update_largest_extent(struct inode *inode,
> - struct extent_tree *et, struct extent_node *en)
> +static inline void __try_update_largest_extent(struct extent_tree *et,
> + struct extent_node *en)
> {
> if (en->ei.len > et->largest.len) {
> et->largest = en->ei;
> - f2fs_mark_inode_dirty_sync(inode, true);
> + et->largest_updated = true;
> }
> }
>
>
next prev parent reply other threads:[~2018-09-10 14:35 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-10 8:18 [PATCH v3] f2fs: avoid sleeping under spin_lock Zhikang Zhang
2018-09-10 14:34 ` Chao Yu [this message]
2018-09-11 20:24 ` Jaegeuk Kim
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