lkml.org 
[lkml]   [2003]   [Nov]   [12]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[RFC 1/5] sysfs-backing-store.patch


o This patch describes the necessary data structures needed for sysfs backing
store and the changes related to initialing sysfs filesystem. sysfs_dirent
represents any element from kobject infrastructure. The element could be
kobject, attribute, binary attribute, attribute group or symlink. kobject
hierarchy is represented by using sysfs_dirent's s_children & s_sibling
links.

o Root of sysfs filesystem is represented by statically allocated sysfs_dirent
structure. Initialisation now does not mount sysfs filesystem and just
does registration.

o The patch also has some support routines internal to sysfs code.


fs/sysfs/mount.c | 41 ++++++++++---------
fs/sysfs/sysfs.h | 103 ++++++++++++++++++++++++++++++++++++++++++++++--
include/linux/kobject.h | 2
include/linux/sysfs.h | 19 ++++++++
4 files changed, 142 insertions(+), 23 deletions(-)

diff -puN include/linux/kobject.h~sysfs-backing-store include/linux/kobject.h
--- linux-2.6.0-test9/include/linux/kobject.h~sysfs-backing-store 2003-11-12 16:02:27.000000000 +0530
+++ linux-2.6.0-test9-maneesh/include/linux/kobject.h 2003-11-12 16:02:27.000000000 +0530
@@ -31,7 +31,7 @@ struct kobject {
struct kobject * parent;
struct kset * kset;
struct kobj_type * ktype;
- struct dentry * dentry;
+ struct sysfs_dirent * s_dirent;
};

extern int kobject_set_name(struct kobject *, const char *, ...)
diff -puN include/linux/sysfs.h~sysfs-backing-store include/linux/sysfs.h
--- linux-2.6.0-test9/include/linux/sysfs.h~sysfs-backing-store 2003-11-12 16:02:27.000000000 +0530
+++ linux-2.6.0-test9-maneesh/include/linux/sysfs.h 2003-11-12 16:14:56.000000000 +0530
@@ -9,6 +9,8 @@
#ifndef _SYSFS_H_
#define _SYSFS_H_

+#include <linux/rwsem.h>
+
struct kobject;
struct module;

@@ -63,6 +65,23 @@ struct attribute_group {
struct attribute ** attrs;
};

+struct sysfs_dirent {
+ struct list_head s_sibling;
+ struct list_head s_children;
+ void * s_element;
+ struct dentry * s_dentry;
+ int s_type;
+ struct rw_semaphore s_rwsem;
+};
+
+/* Types of kobject elements represented by sysfs_dirent */
+#define SYSFS_ROOT 0x0001
+#define SYSFS_KOBJECT 0x0002
+#define SYSFS_KOBJ_ATTR 0x0004
+#define SYSFS_KOBJ_BIN_ATTR 0x0008
+#define SYSFS_KOBJ_ATTR_GROUP 0x0010
+#define SYSFS_KOBJ_LINK 0x0020
+
int sysfs_create_group(struct kobject *, const struct attribute_group *);
void sysfs_remove_group(struct kobject *, const struct attribute_group *);

diff -puN fs/sysfs/mount.c~sysfs-backing-store fs/sysfs/mount.c
--- linux-2.6.0-test9/fs/sysfs/mount.c~sysfs-backing-store 2003-11-12 16:02:27.000000000 +0530
+++ linux-2.6.0-test9-maneesh/fs/sysfs/mount.c 2003-11-12 16:02:27.000000000 +0530
@@ -14,7 +14,6 @@
/* Random magic number */
#define SYSFS_MAGIC 0x62656572

-struct vfsmount *sysfs_mount;
struct super_block * sysfs_sb = NULL;

static struct super_operations sysfs_ops = {
@@ -22,6 +21,15 @@ static struct super_operations sysfs_ops
.drop_inode = generic_delete_inode,
};

+struct sysfs_dirent sysfs_root = {
+ .s_sibling = LIST_HEAD_INIT(sysfs_root.s_sibling),
+ .s_children = LIST_HEAD_INIT(sysfs_root.s_children),
+ .s_element = NULL,
+ .s_dentry = NULL,
+ .s_type = SYSFS_ROOT,
+ .s_rwsem = __RWSEM_INITIALIZER(sysfs_root.s_rwsem),
+};
+
static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *inode;
@@ -35,10 +43,9 @@ static int sysfs_fill_super(struct super

inode = sysfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO);
if (inode) {
- inode->i_op = &simple_dir_inode_operations;
- inode->i_fop = &simple_dir_operations;
- /* directory inodes start off with i_nlink == 2 (for "." entry) */
- inode->i_nlink++;
+ inode->i_op = &sysfs_dir_inode_operations;
+ inode->i_fop = &sysfs_dir_operations;
+ inode->i_nlink += sysfs_get_link_count(&sysfs_root);
} else {
pr_debug("sysfs: could not get root inode\n");
return -ENOMEM;
@@ -50,7 +57,10 @@ static int sysfs_fill_super(struct super
iput(inode);
return -ENOMEM;
}
+ root->d_fsdata = &sysfs_root;
+ sysfs_root.s_dentry = root;
sb->s_root = root;
+
return 0;
}

@@ -60,24 +70,19 @@ static struct super_block *sysfs_get_sb(
return get_sb_single(fs_type, flags, data, sysfs_fill_super);
}

+static void sysfs_kill_super(struct super_block * sb)
+{
+ sysfs_root.s_dentry = NULL;
+ kill_anon_super(sb);
+}
+
static struct file_system_type sysfs_fs_type = {
.name = "sysfs",
.get_sb = sysfs_get_sb,
- .kill_sb = kill_litter_super,
+ .kill_sb = sysfs_kill_super,
};

int __init sysfs_init(void)
{
- int err;
-
- err = register_filesystem(&sysfs_fs_type);
- if (!err) {
- sysfs_mount = kern_mount(&sysfs_fs_type);
- if (IS_ERR(sysfs_mount)) {
- printk(KERN_ERR "sysfs: could not mount!\n");
- err = PTR_ERR(sysfs_mount);
- sysfs_mount = NULL;
- }
- }
- return err;
+ return register_filesystem(&sysfs_fs_type);
}
diff -puN fs/sysfs/sysfs.h~sysfs-backing-store fs/sysfs/sysfs.h
--- linux-2.6.0-test9/fs/sysfs/sysfs.h~sysfs-backing-store 2003-11-12 16:02:27.000000000 +0530
+++ linux-2.6.0-test9-maneesh/fs/sysfs/sysfs.h 2003-11-12 16:02:27.000000000 +0530
@@ -1,13 +1,108 @@

-extern struct vfsmount * sysfs_mount;
+#include <linux/fs.h>
+
+extern struct sysfs_dirent sysfs_root;

extern struct inode * sysfs_new_inode(mode_t mode);
extern int sysfs_create(struct dentry *, int mode, int (*init)(struct inode *));

extern struct dentry * sysfs_get_dentry(struct dentry *, const char *);

-extern int sysfs_add_file(struct dentry * dir, const struct attribute * attr);
-extern void sysfs_hash_and_remove(struct dentry * dir, const char * name);
+extern int sysfs_add_file(struct sysfs_dirent * , const struct attribute * );
+extern void sysfs_hash_and_remove(struct sysfs_dirent *, const char *);

-extern int sysfs_create_subdir(struct kobject *, const char *, struct dentry **);
extern void sysfs_remove_subdir(struct dentry *);
+extern char * sysfs_get_name(struct sysfs_dirent *);
+extern int sysfs_get_link_count(struct sysfs_dirent *);
+extern struct dentry * sysfs_get_new_dentry(struct dentry *, const char *);
+extern int sysfs_init_file(struct inode * inode);
+extern int sysfs_symlink(struct inode *, struct dentry *, const char *);
+
+extern struct inode_operations sysfs_dir_inode_operations;
+extern struct file_operations sysfs_dir_operations;
+extern struct file_operations bin_fops;
+
+struct dentry * sysfs_lookup(struct inode *, struct dentry *, struct nameidata *);
+int sysfs_dir_open(struct inode *inode, struct file *file);
+int sysfs_dir_close(struct inode *inode, struct file *file);
+loff_t sysfs_dir_lseek(struct file *file, loff_t offset, int origin);
+int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir);
+
+static inline struct kobject * sysfs_get_file_kobject(struct dentry * dentry)
+{
+ struct dentry * parent;
+ struct sysfs_dirent * sd;
+
+ parent = dentry->d_parent;
+ sd = parent->d_fsdata;
+ if (sd->s_type == SYSFS_KOBJ_ATTR_GROUP)
+ sd = parent->d_parent->d_fsdata;
+
+ return (struct kobject *) sd->s_element;
+
+}
+
+static inline struct attribute * sysfs_get_file_attr(struct file * filp)
+{
+ struct sysfs_dirent * sd = filp->f_dentry->d_fsdata;
+ return sd->s_element;
+
+}
+
+static inline struct sysfs_dirent *
+sysfs_alloc_dirent(struct sysfs_dirent * parent_sd, void * element, int type)
+{
+ struct sysfs_dirent * sd;
+
+ sd = kmalloc(sizeof(*sd), GFP_KERNEL);
+ if (!sd)
+ return ERR_PTR(-ENOMEM);
+
+ init_rwsem(&sd->s_rwsem);
+ INIT_LIST_HEAD(&sd->s_children);
+ sd->s_element = element;
+ sd->s_type = type;
+ sd->s_dentry = NULL;
+
+ down_write(&parent_sd->s_rwsem);
+ list_add(&sd->s_sibling, &parent_sd->s_children);
+ up_write(&parent_sd->s_rwsem);
+
+ return sd;
+}
+
+static inline void
+sysfs_free_dirent(struct sysfs_dirent * parent_sd, const char * name)
+{
+ struct sysfs_dirent * sd;
+ struct list_head * tmp;
+
+ down_write(&parent_sd->s_rwsem);
+ tmp = parent_sd->s_children.next;
+ while (tmp != &parent_sd->s_children) {
+ sd = list_entry(tmp, struct sysfs_dirent, s_sibling);
+ tmp = tmp->next;
+ if (!strcmp(name, sysfs_get_name(sd))) {
+ list_del(&sd->s_sibling);
+ kfree(sd);
+ }
+ }
+ up_write(&parent_sd->s_rwsem);
+}
+
+static inline void
+sysfs_free_children(struct sysfs_dirent * parent_sd)
+{
+ struct sysfs_dirent * sd;
+ struct list_head * tmp;
+
+ down_write(&parent_sd->s_rwsem);
+ tmp = parent_sd->s_children.next;
+ while (tmp != &parent_sd->s_children) {
+ sd = list_entry(tmp, struct sysfs_dirent, s_sibling);
+ tmp = tmp->next;
+ list_del(&sd->s_sibling);
+ kfree(sd);
+ }
+ up_write(&parent_sd->s_rwsem);
+}
_
--
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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2005-03-22 13:58    [W:0.083 / U:18.996 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site