On 06/05/2017 07:48 PM, Trond Myklebust wrote:
On Mon, 2017-06-05 at 16:05 +0800, Jia-Ju Bai wrote:The driver may sleep under a rcu read lock, and function call path is: nfs_permission (acquire the lock by rcu_read_lock) nfs_do_access nfs_access_add_cache kmalloc(GFP_KERNEL) --> may sleep To fix it, "GFP_KERNEL" is replaced with "GFP_ATOMIC". Signed-off-by: Jia-Ju Bai<baijiaju1990@xxxxxxx> --- fs/nfs/dir.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 32ccd77..7a074db 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -2333,7 +2333,7 @@ static void nfs_access_add_rbtree(struct inode *inode, struct nfs_access_entry *void nfs_access_add_cache(struct inode *inode, structnfs_access_entry *set) { - struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_KERNEL); + struct nfs_access_entry *cache = kmalloc(sizeof(*cache), GFP_ATOMIC); if (cache == NULL) return; RB_CLEAR_NODE(&cache->rb_node);The RCU locked codepath will not ever hit nfs_access_add_rbtree(). It returns with an error code of -ECHILD after the test of "may_block". Cheers Trond
Yes, I think you are right. Thanks, Jia-Ju Bai -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
