Re: [PATCH 2.6] sysfs_remove_dir

[Hanna Linder <hannal@us.ibm.com>]

Maneesh, Pat,

Just wanted to let you know I ran this patch
on 2.6.0-test5 with my input class patch and there
were no problems. Still working on my patch though.

Hanna


--On Monday, September 15, 2003 03:51:28 PM +0530 Maneesh Soni <maneesh@in.ibm.com> wrote:

> 
> Hi Pat,
> 
> sysfs_remove_dir() does not remove the contents of subdirs corresponding
> to the attribute groups of a kobject. The following patch fixes this by first
> removing the subdir contents and then removing thus emptied subdirs along
> with the other attribute files of the kobject and plugs the memory
> leakage resulting from orphan dentries.
> 
> I tested it by inserting and removing "dummy.o" network module and verifying
> that dentires corresponding to "statistics" attribute group are removed.
> 
> Please comment.
> 
> Thanks
> Maneesh
> 
> 
> 
>  o sysfs_remove_dir() has to remove the files in the subdirs (corresponding
>    to the attribute groups) and then remove such empty subdirs along with the 
>    other attribute files for the given kobject. The following patch does this
>    assuming that there are/will be no attribute sub-groups.
> 
> 
>  fs/sysfs/dir.c |   22 +++++++++++++++++-----
>  1 files changed, 17 insertions(+), 5 deletions(-)
> 
> diff -puN fs/sysfs/dir.c~sysfs_remove_dir-fix fs/sysfs/dir.c
> --- linux-2.6.0-test5-mm2/fs/sysfs/dir.c~sysfs_remove_dir-fix	2003-09-15 15:08:45.000000000 +0530
> +++ linux-2.6.0-test5-mm2-maneesh/fs/sysfs/dir.c	2003-09-15 15:26:04.000000000 +0530
> @@ -119,23 +119,30 @@ void sysfs_remove_dir(struct kobject * k
>  {
>  	struct list_head * node;
>  	struct dentry * dentry = dget(kobj->dentry);
> +	struct dentry * parent;
>  
>  	if (!dentry)
>  		return;
>  
>  	pr_debug("sysfs %s: removing dir\n",dentry->d_name.name);
> -	down(&dentry->d_inode->i_sem);
>  
> +	parent = dentry;
> +	down(&parent->d_inode->i_sem);
>  	spin_lock(&dcache_lock);
> -	node = dentry->d_subdirs.next;
> -	while (node != &dentry->d_subdirs) {
> -		struct dentry * d = list_entry(node,struct dentry,d_child);
> +repeat:
> +	node = parent->d_subdirs.next;
> +	while (node != &parent->d_subdirs) {
> +		struct dentry * d = list_entry(node, struct dentry, d_child);
>  		list_del_init(node);
>  
>  		pr_debug(" o %s (%d): ",d->d_name.name,atomic_read(&d->d_count));
>  		if (d->d_inode) {
>  			d = dget_locked(d);
>  			pr_debug("removing");
> +			if (!list_empty(&d->d_subdirs)) {
> +				parent = d;
> +				goto repeat;
> +			}
>  
>  			/**
>  			 * Unlink and unhash.
> @@ -147,7 +154,12 @@ void sysfs_remove_dir(struct kobject * k
>  			spin_lock(&dcache_lock);
>  		}
>  		pr_debug(" done\n");
> -		node = dentry->d_subdirs.next;
> +		node = parent->d_subdirs.next;
> +	}
> +
> +	if (!list_empty(&dentry->d_subdirs)) {
> +		parent = dentry;
> +		goto repeat;
>  	}
>  	list_del_init(&dentry->d_child);
>  	spin_unlock(&dcache_lock);
> 
> _
> 
> -- 
> Maneesh Soni
> Linux Technology Center, 
> IBM Software Lab, Bangalore, India
> email: maneesh@in.ibm.com
> Phone: 91-80-5044999 Fax: 91-80-5268553
> T/L : 9243696
> -
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