From 69000d82eee1b41d88afc75861153b7e514bb777 Mon Sep 17 00:00:00 2001 From: Phong Tran Date: Fri, 13 Dec 2019 22:33:07 +0700 Subject: ext4: use RCU API in debug_print_tree struct ext4_sb_info.system_blks was marked __rcu. But access the pointer without using RCU lock and dereference. Sparse warning with __rcu notation: block_validity.c:139:29: warning: incorrect type in argument 1 (different address spaces) block_validity.c:139:29: expected struct rb_root const * block_validity.c:139:29: got struct rb_root [noderef] * Link: https://lore.kernel.org/r/20191213153306.30744-1-tranmanphong@gmail.com Reviewed-by: Jan Kara Signed-off-by: Phong Tran Signed-off-by: Theodore Ts'o --- fs/ext4/block_validity.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c index d4d4fdfac1a6..1ee04e76bbe0 100644 --- a/fs/ext4/block_validity.c +++ b/fs/ext4/block_validity.c @@ -133,10 +133,13 @@ static void debug_print_tree(struct ext4_sb_info *sbi) { struct rb_node *node; struct ext4_system_zone *entry; + struct ext4_system_blocks *system_blks; int first = 1; printk(KERN_INFO "System zones: "); - node = rb_first(&sbi->system_blks->root); + rcu_read_lock(); + system_blks = rcu_dereference(sbi->system_blks); + node = rb_first(&system_blks->root); while (node) { entry = rb_entry(node, struct ext4_system_zone, node); printk(KERN_CONT "%s%llu-%llu", first ? "" : ", ", @@ -144,6 +147,7 @@ static void debug_print_tree(struct ext4_sb_info *sbi) first = 0; node = rb_next(node); } + rcu_read_unlock(); printk(KERN_CONT "\n"); } -- cgit v1.2.3