[PATCH] sysfs: fix problem with duplicate sysfs directories and files
The following patch checks for existing sysfs_dirent before
preparing new one while creating sysfs directories and files.
Signed-off-by: Maneesh Soni <maneesh@in.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index cfd290d..bea1f4c 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -50,6 +50,32 @@
return sd;
}
+/**
+ *
+ * Return -EEXIST if there is already a sysfs element with the same name for
+ * the same parent.
+ *
+ * called with parent inode's i_mutex held
+ */
+int sysfs_dirent_exist(struct sysfs_dirent *parent_sd,
+ const unsigned char *new)
+{
+ struct sysfs_dirent * sd;
+
+ list_for_each_entry(sd, &parent_sd->s_children, s_sibling) {
+ if (sd->s_element) {
+ const unsigned char *existing = sysfs_get_name(sd);
+ if (strcmp(existing, new))
+ continue;
+ else
+ return -EEXIST;
+ }
+ }
+
+ return 0;
+}
+
+
int sysfs_make_dirent(struct sysfs_dirent * parent_sd, struct dentry * dentry,
void * element, umode_t mode, int type)
{
@@ -102,7 +128,11 @@
mutex_lock(&p->d_inode->i_mutex);
*d = lookup_one_len(n, p, strlen(n));
if (!IS_ERR(*d)) {
- error = sysfs_make_dirent(p->d_fsdata, *d, k, mode, SYSFS_DIR);
+ if (sysfs_dirent_exist(p->d_fsdata, n))
+ error = -EEXIST;
+ else
+ error = sysfs_make_dirent(p->d_fsdata, *d, k, mode,
+ SYSFS_DIR);
if (!error) {
error = sysfs_create(*d, mode, init_dir);
if (!error) {
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index e21f402..5e83e72 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -361,10 +361,12 @@
{
struct sysfs_dirent * parent_sd = dir->d_fsdata;
umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG;
- int error = 0;
+ int error = -EEXIST;
mutex_lock(&dir->d_inode->i_mutex);
- error = sysfs_make_dirent(parent_sd, NULL, (void *) attr, mode, type);
+ if (!sysfs_dirent_exist(parent_sd, attr->name))
+ error = sysfs_make_dirent(parent_sd, NULL, (void *)attr,
+ mode, type);
mutex_unlock(&dir->d_inode->i_mutex);
return error;
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index e38d633..fe23f47 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -82,12 +82,13 @@
int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char * name)
{
struct dentry * dentry = kobj->dentry;
- int error = 0;
+ int error = -EEXIST;
BUG_ON(!kobj || !kobj->dentry || !name);
mutex_lock(&dentry->d_inode->i_mutex);
- error = sysfs_add_link(dentry, name, target);
+ if (!sysfs_dirent_exist(dentry->d_fsdata, name))
+ error = sysfs_add_link(dentry, name, target);
mutex_unlock(&dentry->d_inode->i_mutex);
return error;
}
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 3f8953e..cf11d5b 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -5,6 +5,7 @@
extern struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent *);
extern int sysfs_create(struct dentry *, int mode, int (*init)(struct inode *));
+extern int sysfs_dirent_exist(struct sysfs_dirent *, const unsigned char *);
extern int sysfs_make_dirent(struct sysfs_dirent *, struct dentry *, void *,
umode_t, int);