From 27fb7396f1d97004cf9597c6c6fcbec1f678fa97 Mon Sep 17 00:00:00 2001 From: Zhikang Zhang Date: Mon, 10 Sep 2018 16:18:25 +0800 Subject: [PATCH] f2fs: avoid sleeping under spin_lock 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 Signed-off-by: Zhikang Zhang Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- 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 231b77ef5a53..a70cd2580eae 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 @@ out: 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 @@ do_insert: 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 2ede7083ffc0..a31abd711aa0 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -573,6 +573,7 @@ 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 */ }; /* @@ -755,12 +756,12 @@ 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; } } -- 2.20.1