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 <zhangzhikang1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 231b77ef5a53bffef1e9ce8ab5cfe98a99b6c8c3..a70cd2580eae1eb326b69ddef395d54e582de732 100644 (file)
--- 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 3a8a60e6844cc9c1f8579a263fe038f89fa47894..88b8d5073581beacb897724bd65b63f9f7356cf5 100644 (file)
--- 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;
        }
 }