From: Maneesh Soni <maneesh@in.ibm.com>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Al Viro <viro@parcelfarce.linux.theplanet.co.uk>,
Greg KH <greg@kroah.com>
Subject: [RFC 3/6] sysfs backing store ver 0.5
Date: Wed, 5 May 2004 18:28:33 +0530 [thread overview]
Message-ID: <20040505125833.GD1244@in.ibm.com> (raw)
In-Reply-To: <20040505125815.GC1244@in.ibm.com>
=> changes in version 0.5
o Cahnges to accomodate latest sysfs changes basically using
sysfs_get_kobject() while opening sysfs files.
=> changes in version 0.4
o Made necessary changes for checking DCACHE_SYSFS_CONNECTED flag while
opening the sysfs file in check_perm() and a few changes in variable names
=> changes in version 0.3
o Nil, just re-diffed
=> changes in version 0.2
o Nil, just re-diffed
=> Changes:
o Removed the extra kobject_get from sysfs_release()
=======================================================
o sysfs_create_file() will just link a new sysfs_dirent() structure representing
the attribute file to the kobject's s_children list.
o in sysfs_create() we take extra ref. only for dentries corresponding to
non-regular files or in other words pin only non-leaf dentries.
fs/sysfs/file.c | 65 +++++++++++++++++++++++++++----------------------------
fs/sysfs/inode.c | 14 +++++------
2 files changed, 39 insertions(+), 40 deletions(-)
diff -puN fs/sysfs/file.c~sysfs-leaves-file fs/sysfs/file.c
--- linux-2.6.6-rc3-mm1/fs/sysfs/file.c~sysfs-leaves-file 2004-05-05 10:55:13.000000000 +0530
+++ linux-2.6.6-rc3-mm1-maneesh/fs/sysfs/file.c 2004-05-05 10:55:13.000000000 +0530
@@ -9,14 +9,6 @@
#include "sysfs.h"
-static struct file_operations sysfs_file_operations;
-
-static int init_file(struct inode * inode)
-{
- inode->i_size = PAGE_SIZE;
- inode->i_fop = &sysfs_file_operations;
- return 0;
-}
#define to_subsys(k) container_of(k,struct subsystem,kset.kobj)
#define to_sattr(a) container_of(a,struct subsys_attribute,attr)
@@ -77,8 +69,10 @@ struct sysfs_buffer {
*/
static int fill_read_buffer(struct file * file, struct sysfs_buffer * buffer)
{
- struct attribute * attr = file->f_dentry->d_fsdata;
- struct kobject * kobj = file->f_dentry->d_parent->d_fsdata;
+ struct sysfs_dirent * attr_sd = file->f_dentry->d_fsdata;
+ struct attribute * attr = attr_sd->s_element;
+ struct sysfs_dirent * kobj_sd = file->f_dentry->d_parent->d_fsdata;
+ struct kobject * kobj = kobj_sd->s_element;
struct sysfs_ops * ops = buffer->ops;
int ret = 0;
ssize_t count;
@@ -134,6 +128,9 @@ static int flush_read_buffer(struct sysf
* is in the file's ->d_fsdata. The target object is in the directory's
* ->d_fsdata.
*
+ * It is safe to use ->d_parent->d_fsdata as both dentry and the kobject
+ * are pinned in ->open().
+ *
* We call fill_read_buffer() to allocate and fill the buffer from the
* object's show() method exactly once (if the read is happening from
* the beginning of the file). That should fill the entire buffer with
@@ -198,8 +195,10 @@ fill_write_buffer(struct sysfs_buffer *
static int
flush_write_buffer(struct file * file, struct sysfs_buffer * buffer, size_t count)
{
- struct attribute * attr = file->f_dentry->d_fsdata;
- struct kobject * kobj = file->f_dentry->d_parent->d_fsdata;
+ struct sysfs_dirent * attr_sd = file->f_dentry->d_fsdata;
+ struct attribute * attr = attr_sd->s_element;
+ struct sysfs_dirent * kobj_sd = file->f_dentry->d_parent->d_fsdata;
+ struct kobject * kobj = kobj_sd->s_element;
struct sysfs_ops * ops = buffer->ops;
return ops->store(kobj,attr,buffer->page,count);
@@ -239,7 +238,8 @@ sysfs_write_file(struct file *file, cons
static int check_perm(struct inode * inode, struct file * file)
{
struct kobject *kobj = sysfs_get_kobject(file->f_dentry->d_parent);
- struct attribute * attr = file->f_dentry->d_fsdata;
+ struct sysfs_dirent * attr_sd = file->f_dentry->d_fsdata;
+ struct attribute * attr = attr_sd->s_element;
struct sysfs_buffer * buffer;
struct sysfs_ops * ops = NULL;
int error = 0;
@@ -320,8 +320,10 @@ static int sysfs_open_file(struct inode
static int sysfs_release(struct inode * inode, struct file * filp)
{
- struct kobject * kobj = filp->f_dentry->d_parent->d_fsdata;
- struct attribute * attr = filp->f_dentry->d_fsdata;
+ struct sysfs_dirent * attr_sd = filp->f_dentry->d_fsdata;
+ struct attribute * attr = attr_sd->s_element;
+ struct sysfs_dirent * kobj_sd = filp->f_dentry->d_parent->d_fsdata;
+ struct kobject * kobj = kobj_sd->s_element;
struct sysfs_buffer * buffer = filp->private_data;
if (kobj)
@@ -336,7 +338,7 @@ static int sysfs_release(struct inode *
return 0;
}
-static struct file_operations sysfs_file_operations = {
+struct file_operations sysfs_file_operations = {
.read = sysfs_read_file,
.write = sysfs_write_file,
.llseek = generic_file_llseek,
@@ -345,23 +347,20 @@ static struct file_operations sysfs_file
};
-int sysfs_add_file(struct dentry * dir, const struct attribute * attr)
+int sysfs_add_file(struct dentry * parent, const struct attribute * attr, int t)
{
- struct dentry * dentry;
- int error;
+ struct sysfs_dirent * sd;
+ struct sysfs_dirent * parent_sd = parent->d_fsdata;
+ int error = 0;
- down(&dir->d_inode->i_sem);
- dentry = sysfs_get_dentry(dir,attr->name);
- if (!IS_ERR(dentry)) {
- error = sysfs_create(dentry,
- (attr->mode & S_IALLUGO) | S_IFREG,
- init_file);
- if (!error)
- dentry->d_fsdata = (void *)attr;
- dput(dentry);
- } else
- error = PTR_ERR(dentry);
- up(&dir->d_inode->i_sem);
+ down(&parent->d_inode->i_sem);
+ sd = sysfs_new_dirent(parent_sd, (void *) attr, t);
+ if (!sd)
+ error = -ENOMEM;
+ else
+ sd->s_mode = (attr->mode & S_IALLUGO) | S_IFREG ;
+ up(&parent->d_inode->i_sem);
+
return error;
}
@@ -374,8 +373,8 @@ int sysfs_add_file(struct dentry * dir,
int sysfs_create_file(struct kobject * kobj, const struct attribute * attr)
{
- if (kobj && attr)
- return sysfs_add_file(kobj->dentry,attr);
+ if (kobj && kobj->dentry && attr)
+ return sysfs_add_file(kobj->dentry, attr, SYSFS_KOBJ_ATTR);
return -EINVAL;
}
diff -puN fs/sysfs/inode.c~sysfs-leaves-file fs/sysfs/inode.c
--- linux-2.6.6-rc3-mm1/fs/sysfs/inode.c~sysfs-leaves-file 2004-05-05 10:55:13.000000000 +0530
+++ linux-2.6.6-rc3-mm1-maneesh/fs/sysfs/inode.c 2004-05-05 10:55:14.000000000 +0530
@@ -11,6 +11,8 @@
#include <linux/pagemap.h>
#include <linux/namei.h>
#include <linux/backing-dev.h>
+#include "sysfs.h"
+
extern struct super_block * sysfs_sb;
static struct address_space_operations sysfs_aops = {
@@ -61,7 +63,8 @@ int sysfs_create(struct dentry * dentry,
error = init(inode);
if (!error) {
d_instantiate(dentry, inode);
- dget(dentry); /* Extra count - pin the dentry in core */
+ if (S_ISDIR(mode))
+ dget(dentry); /* pin only directory dentry in core */
} else
iput(inode);
Done:
@@ -97,18 +100,15 @@ void sysfs_hash_and_remove(struct dentry
atomic_read(&victim->d_count));
d_drop(victim);
- /* release the target kobject in case of
- * a symlink
- */
- if (S_ISLNK(victim->d_inode->i_mode))
- kobject_put(victim->d_fsdata);
- simple_unlink(dir->d_inode,victim);
+ if (S_ISDIR(victim->d_inode->i_mode))
+ simple_unlink(dir->d_inode,victim);
}
/*
* Drop reference from sysfs_get_dentry() above.
*/
dput(victim);
}
+ sysfs_remove_dirent(dir->d_fsdata, name);
up(&dir->d_inode->i_sem);
}
_
--
Maneesh Soni
Linux Technology Center,
IBM Software Lab, Bangalore, India
email: maneesh@in.ibm.com
Phone: 91-80-25044999 Fax: 91-80-25268553
T/L : 9243696
next prev parent reply other threads:[~2004-05-05 12:53 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-05-05 12:57 [RFC 0/6] sysfs backing store ver 0.5 Maneesh Soni
2004-05-05 12:57 ` [RFC 1/6] " Maneesh Soni
2004-05-05 12:58 ` [RFC 2/6] " Maneesh Soni
2004-05-05 12:58 ` Maneesh Soni [this message]
2004-05-05 12:59 ` [RFC 4/6] " Maneesh Soni
2004-05-05 12:59 ` [RFC 5/6] " Maneesh Soni
2004-05-05 12:59 ` [RFC 6/6] " Maneesh Soni
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