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authorEric W. Biederman <ebiederm@xmission.com>2011-10-12 22:02:43 +0000
committerDavid S. Miller <davem@davemloft.net>2011-10-19 19:24:16 -0400
commit903e21e2eea036f6947f523f732e28b33a63ed0f (patch)
treee63059c0acbfde6eca66cd9c293a984e64d6cab8 /fs/sysfs
parent23396180a9770df2c6a694bbb689c12bdf792f94 (diff)
downloadlwn-903e21e2eea036f6947f523f732e28b33a63ed0f.tar.gz
lwn-903e21e2eea036f6947f523f732e28b33a63ed0f.zip
sysfs: Reject with a warning invalid uses of tagged directories.
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>
Diffstat (limited to 'fs/sysfs')
-rw-r--r--fs/sysfs/dir.c14
-rw-r--r--fs/sysfs/file.c3
2 files changed, 14 insertions, 3 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 352d26d98c0a..26f370a9b5ce 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -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;
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 07c1b4ec00df..d4e6080b4b20 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -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);