Following function can drops d_count twice against one reference
by lookup_one_len.
<SOURCE>
/**
* sysfs_update_file - update the modified timestamp on an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
*/
int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
{
struct dentry * dir = kobj->dentry;
struct dentry * victim;
int res = -ENOENT;
mutex_lock(&dir->d_inode->i_mutex);
victim = lookup_one_len(attr->name, dir, strlen(attr->name));
if (!IS_ERR(victim)) {
/* make sure dentry is really there */
if (victim->d_inode &&
(victim->d_parent->d_inode == dir->d_inode)) {
victim->d_inode->i_mtime = CURRENT_TIME;
fsnotify_modify(victim);
/**
* Drop reference from initial sysfs_get_dentry().
*/
dput(victim);
res = 0;
} else
d_drop(victim);
/**
* Drop the reference acquired from sysfs_get_dentry() above.
*/
dput(victim);
}
mutex_unlock(&dir->d_inode->i_mutex);
return res;
}
</SOURCE>
PCI-hotplug (drivers/pci/hotplug/pci_hotplug_core.c) is only user of
this function. I confirmed that dentry of /sys/bus/pci/slots/XXX/*
have negative d_count value.
This patch removes unnecessary dput().
Signed-off-by: Hidetoshi Seto <[email protected]>
---
fs/sysfs/file.c | 5 -----
1 files changed, 5 deletions(-)
Index: linux-2.6.18/fs/sysfs/file.c
===================================================================
--- linux-2.6.18.orig/fs/sysfs/file.c
+++ linux-2.6.18/fs/sysfs/file.c
@@ -483,11 +483,6 @@
(victim->d_parent->d_inode == dir->d_inode)) {
victim->d_inode->i_mtime = CURRENT_TIME;
fsnotify_modify(victim);
-
- /**
- * Drop reference from initial sysfs_get_dentry().
- */
- dput(victim);
res = 0;
} else
d_drop(victim);
And the obsolete comment should be updated (or totally removed).
Signed-off-by: Hidetoshi Seto <[email protected]>
---
fs/sysfs/file.c | 2 +-
1 files changed, 1 insertion(+), 1 deletion(-)
Index: linux-2.6.18/fs/sysfs/file.c
===================================================================
--- linux-2.6.18.orig/fs/sysfs/file.c
+++ linux-2.6.18/fs/sysfs/file.c
@@ -488,7 +488,7 @@
d_drop(victim);
/**
- * Drop the reference acquired from sysfs_get_dentry() above.
+ * Drop the reference acquired from lookup_one_len() above.
*/
dput(victim);
}
On Wed, Sep 20, 2006 at 04:38:00PM +0900, Hidetoshi Seto wrote:
> Following function can drops d_count twice against one reference
> by lookup_one_len.
>
> <SOURCE>
> /**
> * sysfs_update_file - update the modified timestamp on an object attribute.
> * @kobj: object we're acting for.
> * @attr: attribute descriptor.
> */
> int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
> {
> struct dentry * dir = kobj->dentry;
> struct dentry * victim;
> int res = -ENOENT;
>
> mutex_lock(&dir->d_inode->i_mutex);
> victim = lookup_one_len(attr->name, dir, strlen(attr->name));
> if (!IS_ERR(victim)) {
> /* make sure dentry is really there */
> if (victim->d_inode &&
> (victim->d_parent->d_inode == dir->d_inode)) {
> victim->d_inode->i_mtime = CURRENT_TIME;
> fsnotify_modify(victim);
>
> /**
> * Drop reference from initial sysfs_get_dentry().
> */
> dput(victim);
> res = 0;
> } else
> d_drop(victim);
>
> /**
> * Drop the reference acquired from sysfs_get_dentry() above.
> */
> dput(victim);
> }
> mutex_unlock(&dir->d_inode->i_mutex);
>
> return res;
> }
> </SOURCE>
>
> PCI-hotplug (drivers/pci/hotplug/pci_hotplug_core.c) is only user of
> this function. I confirmed that dentry of /sys/bus/pci/slots/XXX/*
> have negative d_count value.
>
> This patch removes unnecessary dput().
>
> Signed-off-by: Hidetoshi Seto <[email protected]>
>
> ---
> fs/sysfs/file.c | 5 -----
> 1 files changed, 5 deletions(-)
>
> Index: linux-2.6.18/fs/sysfs/file.c
> ===================================================================
> --- linux-2.6.18.orig/fs/sysfs/file.c
> +++ linux-2.6.18/fs/sysfs/file.c
> @@ -483,11 +483,6 @@
> (victim->d_parent->d_inode == dir->d_inode)) {
> victim->d_inode->i_mtime = CURRENT_TIME;
> fsnotify_modify(victim);
> -
> - /**
> - * Drop reference from initial sysfs_get_dentry().
> - */
> - dput(victim);
> res = 0;
> } else
> d_drop(victim);
>
> -
>
Looks good to me..
Thanks
Maneesh
This is a note to let you know that I've just added the patch titled
Subject: sysfs: remove duplicated dput in sysfs_update_file
to my gregkh-2.6 tree. Its filename is
sysfs-remove-duplicated-dput-in-sysfs_update_file.patch
This tree can be found at
http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/
>From [email protected] Wed Sep 20 00:35:46 2006
Message-ID: <[email protected]>
Date: Wed, 20 Sep 2006 16:38:00 +0900
From: Hidetoshi Seto <[email protected]>
To: Greg KH <[email protected]>
Cc: Linux Kernel list <[email protected]>
Subject: sysfs: remove duplicated dput in sysfs_update_file
Following function can drops d_count twice against one reference
by lookup_one_len.
<SOURCE>
/**
* sysfs_update_file - update the modified timestamp on an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
*/
int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
{
struct dentry * dir = kobj->dentry;
struct dentry * victim;
int res = -ENOENT;
mutex_lock(&dir->d_inode->i_mutex);
victim = lookup_one_len(attr->name, dir, strlen(attr->name));
if (!IS_ERR(victim)) {
/* make sure dentry is really there */
if (victim->d_inode &&
(victim->d_parent->d_inode == dir->d_inode)) {
victim->d_inode->i_mtime = CURRENT_TIME;
fsnotify_modify(victim);
/**
* Drop reference from initial sysfs_get_dentry().
*/
dput(victim);
res = 0;
} else
d_drop(victim);
/**
* Drop the reference acquired from sysfs_get_dentry() above.
*/
dput(victim);
}
mutex_unlock(&dir->d_inode->i_mutex);
return res;
}
</SOURCE>
PCI-hotplug (drivers/pci/hotplug/pci_hotplug_core.c) is only user of
this function. I confirmed that dentry of /sys/bus/pci/slots/XXX/*
have negative d_count value.
This patch removes unnecessary dput().
Signed-off-by: Hidetoshi Seto <[email protected]>
Acked-by: Maneesh Soni <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/sysfs/file.c | 5 -----
1 file changed, 5 deletions(-)
--- gregkh-2.6.orig/fs/sysfs/file.c
+++ gregkh-2.6/fs/sysfs/file.c
@@ -497,11 +497,6 @@ int sysfs_update_file(struct kobject * k
(victim->d_parent->d_inode == dir->d_inode)) {
victim->d_inode->i_mtime = CURRENT_TIME;
fsnotify_modify(victim);
-
- /**
- * Drop reference from initial sysfs_get_dentry().
- */
- dput(victim);
res = 0;
} else
d_drop(victim);
Patches currently in gregkh-2.6 which might be from [email protected] are
driver/sysfs-remove-duplicated-dput-in-sysfs_update_file.patch
driver/sysfs-update-obsolete-comment-in-sysfs_update_file.patch
This is a note to let you know that I've just added the patch titled
Subject: sysfs: update obsolete comment in sysfs_update_file
to my gregkh-2.6 tree. Its filename is
sysfs-update-obsolete-comment-in-sysfs_update_file.patch
This tree can be found at
http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/
>From [email protected] Wed Sep 20 00:46:42 2006
Message-ID: <[email protected]>
Date: Wed, 20 Sep 2006 16:49:02 +0900
From: Hidetoshi Seto <[email protected]>
To: Greg KH <[email protected]>
Cc: Linux Kernel list <[email protected]>
Subject: sysfs: update obsolete comment in sysfs_update_file
And the obsolete comment should be updated (or totally removed).
Signed-off-by: Hidetoshi Seto <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/sysfs/file.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- gregkh-2.6.orig/fs/sysfs/file.c
+++ gregkh-2.6/fs/sysfs/file.c
@@ -502,7 +502,7 @@ int sysfs_update_file(struct kobject * k
d_drop(victim);
/**
- * Drop the reference acquired from sysfs_get_dentry() above.
+ * Drop the reference acquired from lookup_one_len() above.
*/
dput(victim);
}
Patches currently in gregkh-2.6 which might be from [email protected] are
driver/sysfs-remove-duplicated-dput-in-sysfs_update_file.patch
driver/sysfs-update-obsolete-comment-in-sysfs_update_file.patch