sysfs: Reject with a warning invalid uses of tagged directories. (903e21e2) · Commits · 戴 / test

sysfs is a core piece of ifrastructure that many people use and few people have all of the rules in their head on how to use it correctly. Add warnings for people using tagged directories improperly to that any misuses can be caught and diagnosed quickly. A single inexpensive test in sysfs_find_dirent is almost sufficient to catch all possible misuses. An additional warning is needed in sysfs_add_dirent so that we actually fail when attempting to add an untagged dirent in a tagged directory. Signed-off-by:

Eric W. Biederman <ebiederm@xmission.com> Acked-by:

Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by:

David S. Miller <davem@davemloft.net>

fs/sysfs/dir.c

+14 −0

Original line number	Diff line number	Diff line
		@@ -384,6 +384,13 @@ int __sysfs_add_one(struct sysfs_addrm_cxt acxt, struct sysfs_dirent sd)
		{
		struct sysfs_inode_attrs *ps_iattr;

		if (!!sysfs_ns_type(acxt->parent_sd) != !!sd->s_ns) {
		WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
		sysfs_ns_type(acxt->parent_sd)? "required": "invalid",
		acxt->parent_sd->s_name, sd->s_name);
		return -EINVAL;
		}

		if (sysfs_find_dirent(acxt->parent_sd, sd->s_ns, sd->s_name))
		return -EEXIST;

		@@ -542,6 +549,13 @@ struct sysfs_dirent sysfs_find_dirent(struct sysfs_dirent parent_sd,
		{
		struct sysfs_dirent *sd;

		if (!!sysfs_ns_type(parent_sd) != !!ns) {
		WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
		sysfs_ns_type(parent_sd)? "required": "invalid",
		parent_sd->s_name, name);
		return NULL;
		}

		for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling) {
		if (sd->s_ns != ns)
		continue;

fs/sysfs/file.c

+0 −3

Original line number	Diff line number	Diff line
		@@ -466,9 +466,6 @@ void sysfs_notify(struct kobject k, const char dir, const char *attr)
		mutex_lock(&sysfs_mutex);

		if (sd && dir)
		/* Only directories are tagged, so no need to pass
		* a tag explicitly.
		*/
		sd = sysfs_find_dirent(sd, NULL, dir);
		if (sd && attr)
		sd = sysfs_find_dirent(sd, NULL, attr);

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