[PATCH 24/75] sysfs: make sysfs_add_one() automatically check for duplicate entry

Greg Kroah-Hartman
2007-10-12T22:31:48Z

From: Tejun Heo <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 <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
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(-)

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 354675a..6206032 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -491,9 +491,16 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
*
* 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_cxt *acxt, struct sysfs_dirent *sd)
acxt->cnt++;

sysfs_link_sibling(sd);
+
+ return 0;
}

/**
@@ -691,6 +700,7 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
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 *kobj, struct sysfs_dirent *parent_sd,

/* 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,
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index ea0e494..33bb340 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -397,6 +397,7 @@ int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr,
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 *dir_sd, const struct attribute *attr,
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;
}

diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index c129f30..a6b13f1 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -91,14 +91,11 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char
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;

diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 32b8b64..bb3f0c9 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -62,7 +62,7 @@ extern struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);
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);
--
1.5.3.4