On Thu, Mar 09, 2006 at 07:40:14PM +0530, Maneesh Soni wrote:
> On Wed, Mar 08, 2006 at 09:58:16PM -0800, Greg KH wrote:
>
> >
> > I have a test module that shows this at:
> > http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/gregkh/sysfs-test.patch
> > just load the 'gregkh' module and look in /sys/class/gregkh/ to see the
> > duplicate "gregkh1" directories.
> >
>
> Thnaks for the testcase, I could verify the following patch using this. I
> don't see the duplicate "gregkh1" directories. Please queue it for post 2.6.16
> if you are ok with it.
Looks good. I tweaked it a bit (returned -EEXIST from functions if the
file already existed), and renamed the function to play nicer in the
global namespace. Updated patch is below
Thanks a lot for doing this, I appreciate it.
greg k-h
-------------
>From [email protected] Thu Mar 9 06:13:04 2006
Date: Thu, 9 Mar 2006 19:40:14 +0530
From: Maneesh Soni <[email protected]>
To: Greg KH <[email protected]>
Cc: Patrick Mochel <[email protected]>
Subject: sysfs: fix problem with duplicate sysfs directories and files
Message-ID: <[email protected]>
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 <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
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
@@ -450,10 +450,12 @@ 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);
-
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