kernfs: fix kernfs_node_from_dentry() (f41c5934) · Commits · 戴 / test

Currently kernfs_node_from_dentry() returns NULL for root dentry, because root_dentry->d_op == NULL. Due to this bug cgroupstats_build() returns -EINVAL for root cgroup. # mount -t cgroup -o cpuacct /cgroup # Documentation/accounting/getdelays -C /cgroup fatal reply error, errno -22 With this fix: # Documentation/accounting/getdelays -C /cgroup sleeping 305, blocked 0, running 1, stopped 0, uninterruptible 1 Signed-off-by:

Li Zefan <lizefan@huawei.com> Acked-by:

Tejun Heo <tj@kernel.org> Signed-off-by:

Greg Kroah-Hartman <gregkh@linuxfoundation.org>

fs/kernfs/dir.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -500,7 +500,7 @@ const struct dentry_operations kernfs_dops = {
		*/
		struct kernfs_node kernfs_node_from_dentry(struct dentry dentry)
		{
		if (dentry->d_op == &kernfs_dops)
		if (dentry->d_sb->s_op == &kernfs_sops)
		return dentry->d_fsdata;
		return NULL;
		}

fs/kernfs/kernfs-internal.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -65,6 +65,7 @@ struct kernfs_super_info {
		};
		#define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info))

		extern const struct super_operations kernfs_sops;
		extern struct kmem_cache *kernfs_node_cache;

		/*

fs/kernfs/mount.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -39,7 +39,7 @@ static int kernfs_sop_show_options(struct seq_file sf, struct dentry dentry)
		return 0;
		}

		static const struct super_operations kernfs_sops = {
		const struct super_operations kernfs_sops = {
		.statfs = simple_statfs,
		.drop_inode = generic_delete_inode,
		.evict_inode = kernfs_evict_inode,

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