From htejun@gmail.com Thu Aug 2 14:30:35 2007 From: Tejun Heo Date: Thu, 2 Aug 2007 21:38:03 +0900 Subject: [PATCH 4/5] sysfs: make sysfs_add_one() automatically check for duplicate entry To: ebiederm@xmission.com, gregkh@suse.de, linux-kernel@vger.kernel.org, satyam@infradead.org, cornelia.huck@de.ibm.com, stern@rowland.harvard.edu, htejun@gmail.com Cc: Tejun Heo Message-ID: <11860582831609-git-send-email-htejun@gmail.com> Make sysfs_add_one() check for duplicate entry and return -EEXIST if such entry exists. This simplifies node addition code a bit. This patch doesn't introduce any noticeable behavior change. Signed-off-by: Tejun Heo Acked-by: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 26 +++++++++++++++++--------- fs/sysfs/file.c | 12 +++++------- fs/sysfs/symlink.c | 9 +++------ fs/sysfs/sysfs.h | 2 +- 4 files changed, 26 insertions(+), 23 deletions(-) --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -491,9 +491,16 @@ void sysfs_addrm_start(struct sysfs_addr * * LOCKING: * Determined by sysfs_addrm_start(). + * + * RETURNS: + * 0 on success, -EEXIST if entry with the given name already + * exists. */ -void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) +int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) { + if (sysfs_find_dirent(acxt->parent_sd, sd->s_name)) + return -EEXIST; + sd->s_parent = sysfs_get(acxt->parent_sd); if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode) @@ -502,6 +509,8 @@ void sysfs_add_one(struct sysfs_addrm_cx acxt->cnt++; sysfs_link_sibling(sd); + + return 0; } /** @@ -691,6 +700,7 @@ static int create_dir(struct kobject *ko umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; + int rc; /* allocate */ sd = sysfs_new_dirent(name, mode, SYSFS_DIR); @@ -700,17 +710,15 @@ static int create_dir(struct kobject *ko /* link in */ sysfs_addrm_start(&acxt, parent_sd); + rc = sysfs_add_one(&acxt, sd); + sysfs_addrm_finish(&acxt); - if (!sysfs_find_dirent(parent_sd, name)) - sysfs_add_one(&acxt, sd); - - if (!sysfs_addrm_finish(&acxt)) { + if (rc == 0) + *p_sd = sd; + else sysfs_put(sd); - return -EEXIST; - } - *p_sd = sd; - return 0; + return rc; } int sysfs_create_subdir(struct kobject *kobj, const char *name, --- a/fs/sysfs/file.c +++ b/fs/sysfs/file.c @@ -397,6 +397,7 @@ int sysfs_add_file(struct sysfs_dirent * umode_t mode = (attr->mode & S_IALLUGO) | S_IFREG; struct sysfs_addrm_cxt acxt; struct sysfs_dirent *sd; + int rc; sd = sysfs_new_dirent(attr->name, mode, type); if (!sd) @@ -404,16 +405,13 @@ int sysfs_add_file(struct sysfs_dirent * sd->s_elem.attr.attr = (void *)attr; sysfs_addrm_start(&acxt, dir_sd); + rc = sysfs_add_one(&acxt, sd); + sysfs_addrm_finish(&acxt); - if (!sysfs_find_dirent(dir_sd, attr->name)) - sysfs_add_one(&acxt, sd); - - if (!sysfs_addrm_finish(&acxt)) { + if (rc) sysfs_put(sd); - return -EEXIST; - } - return 0; + return rc; } --- a/fs/sysfs/symlink.c +++ b/fs/sysfs/symlink.c @@ -91,14 +91,11 @@ int sysfs_create_link(struct kobject * k target_sd = NULL; /* reference is now owned by the symlink */ sysfs_addrm_start(&acxt, parent_sd); + error = sysfs_add_one(&acxt, sd); + sysfs_addrm_finish(&acxt); - if (!sysfs_find_dirent(parent_sd, name)) - sysfs_add_one(&acxt, sd); - - if (!sysfs_addrm_finish(&acxt)) { - error = -EEXIST; + if (error) goto out_put; - } return 0; --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -62,7 +62,7 @@ extern struct sysfs_dirent *sysfs_get_ac extern void sysfs_put_active_two(struct sysfs_dirent *sd); extern void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *parent_sd); -extern void sysfs_add_one(struct sysfs_addrm_cxt *acxt, +extern int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd); extern void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);