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Commit bc755553 authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
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sysfs, kernfs: make inode number ida per kernfs_root 



kernfs is being updated to allow multiple sysfs_dirent hierarchies so
that it can also be used by other users.  Currently, inode number is
allocated using a global ida, sysfs_ino_ida; however, inos for
different hierarchies should be handled separately.

This patch makes ino allocation per kernfs_root.  sysfs_ino_ida is
replaced by kernfs_root->ino_ida and sysfs_new_dirent() is updated to
take @root and allocate ino from it.  ida_simple_get/remove() are used
instead of sysfs_ino_lock and sysfs_alloc/free_ino().

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ba7443bc

fs/kernfs/dir.c

+13 −34
Original line number Diff line number Diff line
@@ -21,9 +21,6 @@ DEFINE_MUTEX(sysfs_mutex); 


#define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb)



static DEFINE_SPINLOCK(sysfs_ino_lock);

static DEFINE_IDA(sysfs_ino_ida);



/**

 *	sysfs_name_hash

 *	@name: Null terminated string to hash
@@ -205,32 +202,6 @@ static void sysfs_deactivate(struct sysfs_dirent *sd) 
	rwsem_release(&sd->dep_map, 1, _RET_IP_);

}



static int sysfs_alloc_ino(unsigned int *pino)

{

	int ino, rc;



 retry:

	spin_lock(&sysfs_ino_lock);

	rc = ida_get_new_above(&sysfs_ino_ida, 1, &ino);

	spin_unlock(&sysfs_ino_lock);



	if (rc == -EAGAIN) {

		if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL))

			goto retry;

		rc = -ENOMEM;

	}



	*pino = ino;

	return rc;

}



static void sysfs_free_ino(unsigned int ino)

{

	spin_lock(&sysfs_ino_lock);

	ida_remove(&sysfs_ino_ida, ino);

	spin_unlock(&sysfs_ino_lock);

}



/**

 * kernfs_get - get a reference count on a sysfs_dirent

 * @sd: the target sysfs_dirent
@@ -276,7 +247,7 @@ void kernfs_put(struct sysfs_dirent *sd) 
		security_release_secctx(sd->s_iattr->ia_secdata,

					sd->s_iattr->ia_secdata_len);

	kfree(sd->s_iattr);

	sysfs_free_ino(sd->s_ino);

	ida_simple_remove(&root->ino_ida, sd->s_ino);

	kmem_cache_free(sysfs_dir_cachep, sd);



	sd = parent_sd;
@@ -285,6 +256,7 @@ void kernfs_put(struct sysfs_dirent *sd) 
			goto repeat;

	} else {

		/* just released the root sd, free @root too */

		ida_destroy(&root->ino_ida);

		kfree(root);

	}

}
@@ -360,10 +332,12 @@ const struct dentry_operations sysfs_dentry_ops = { 
	.d_release	= sysfs_dentry_release,

};



struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)

struct sysfs_dirent *sysfs_new_dirent(struct kernfs_root *root,

				      const char *name, umode_t mode, int type)

{

	char *dup_name = NULL;

	struct sysfs_dirent *sd;

	int ret;



	if (type & SYSFS_COPY_NAME) {

		name = dup_name = kstrdup(name, GFP_KERNEL);
@@ -375,8 +349,10 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) 
	if (!sd)

		goto err_out1;



	if (sysfs_alloc_ino(&sd->s_ino))

	ret = ida_simple_get(&root->ino_ida, 1, 0, GFP_KERNEL);

	if (ret < 0)

		goto err_out2;

	sd->s_ino = ret;



	atomic_set(&sd->s_count, 1);

	atomic_set(&sd->s_active, 0);
@@ -628,8 +604,11 @@ struct kernfs_root *kernfs_create_root(void *priv) 
	if (!root)

		return ERR_PTR(-ENOMEM);



	sd = sysfs_new_dirent("", S_IFDIR | S_IRUGO | S_IXUGO, SYSFS_DIR);

	ida_init(&root->ino_ida);



	sd = sysfs_new_dirent(root, "", S_IFDIR | S_IRUGO | S_IXUGO, SYSFS_DIR);

	if (!sd) {

		ida_destroy(&root->ino_ida);

		kfree(root);

		return ERR_PTR(-ENOMEM);

	}
@@ -674,7 +653,7 @@ struct sysfs_dirent *kernfs_create_dir_ns(struct sysfs_dirent *parent, 
	int rc;



	/* allocate */

	sd = sysfs_new_dirent(name, mode, SYSFS_DIR);

	sd = sysfs_new_dirent(kernfs_root(parent), name, mode, SYSFS_DIR);

	if (!sd)

		return ERR_PTR(-ENOMEM);

fs/kernfs/file.c

+2 −2
Original line number Diff line number Diff line
@@ -775,8 +775,8 @@ struct sysfs_dirent *kernfs_create_file_ns_key(struct sysfs_dirent *parent, 
	struct sysfs_dirent *sd;

	int rc;



	sd = sysfs_new_dirent(name, (mode & S_IALLUGO) | S_IFREG,

			      SYSFS_KOBJ_ATTR);

	sd = sysfs_new_dirent(kernfs_root(parent), name,

			      (mode & S_IALLUGO) | S_IFREG, SYSFS_KOBJ_ATTR);

	if (!sd)

		return ERR_PTR(-ENOMEM);

fs/kernfs/kernfs-internal.h

+2 −1
Original line number Diff line number Diff line
@@ -160,7 +160,8 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt); 
int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,

		  struct sysfs_dirent *parent_sd);

void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);

struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type);

struct sysfs_dirent *sysfs_new_dirent(struct kernfs_root *root,

				      const char *name, umode_t mode, int type);



/*

 * file.c

fs/kernfs/symlink.c

+2 −1
Original line number Diff line number Diff line
@@ -30,7 +30,8 @@ struct sysfs_dirent *kernfs_create_link(struct sysfs_dirent *parent, 
	struct sysfs_addrm_cxt acxt;

	int error;



	sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK);

	sd = sysfs_new_dirent(kernfs_root(parent), name, S_IFLNK|S_IRWXUGO,

			      SYSFS_KOBJ_LINK);

	if (!sd)

		return ERR_PTR(-ENOMEM);

include/linux/kernfs.h

+4 −0
Original line number Diff line number Diff line
@@ -11,6 +11,7 @@ 
#include <linux/err.h>

#include <linux/list.h>

#include <linux/mutex.h>

#include <linux/idr.h>

#include <linux/lockdep.h>



struct file;
@@ -23,6 +24,9 @@ struct sysfs_dirent; 
struct kernfs_root {

	/* published fields */

	struct sysfs_dirent	*sd;



	/* private fields, do not use outside kernfs proper */

	struct ida		ino_ida;

};



struct sysfs_open_file {