From maneesh@in.ibm.com Thu Mar 9 06:13:04 2006 Date: Thu, 9 Mar 2006 19:40:14 +0530 From: Maneesh Soni To: Greg KH Cc: Patrick Mochel Subject: sysfs: fix problem with duplicate sysfs directories and files Message-ID: <20060309141014.GB10667@in.ibm.com> Content-Disposition: inline The following patch checks for existing sysfs_dirent before preparing new one while creating sysfs directories and files. Signed-off-by: Maneesh Soni Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 30 +++++++++++++++++++++++++++++- fs/sysfs/file.c | 6 ++++-- fs/sysfs/symlink.c | 5 +++-- fs/sysfs/sysfs.h | 1 + 4 files changed, 37 insertions(+), 5 deletions(-) --- gregkh-2.6.orig/fs/sysfs/dir.c +++ gregkh-2.6/fs/sysfs/dir.c @@ -51,6 +51,30 @@ static struct sysfs_dirent * sysfs_new_d 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) { + 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) { @@ -117,7 +141,11 @@ static int create_dir(struct kobject * k 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) { --- gregkh-2.6.orig/fs/sysfs/file.c +++ gregkh-2.6/fs/sysfs/file.c @@ -436,10 +436,12 @@ int sysfs_add_file(struct dentry * dir, { 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; --- gregkh-2.6.orig/fs/sysfs/symlink.c +++ gregkh-2.6/fs/sysfs/symlink.c @@ -82,12 +82,13 @@ exit1: 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; } --- gregkh-2.6.orig/fs/sysfs/sysfs.h +++ gregkh-2.6/fs/sysfs/sysfs.h @@ -5,6 +5,7 @@ extern kmem_cache_t *sysfs_dir_cachep; 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);