Commit 41fc1c27 authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
Browse files

sysfs: make sysfs_add/remove_one() call link/unlink_sibling() implictly 



When adding or removing a sysfs_dirent, the user used to be required
to call link/unlink separately.  It was for two reasons - code looked
like that before sysfs_addrm_cxt conversion and to avoid looping
through parent_sd->children list twice during removal.

Performance optimization during removal just isn't worth it.  Make
sysfs_add/remove_one() call sysfs_link/unlink_sibing() implicitly.
This makes code simpler albeit slightly less efficient.  This change
doesn't introduce any noticeable behavior change.

Signed-off-by: default avatarTejun Heo <htejun@gmail.com>
Acked-by: default avatarCornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent ff869de7

fs/sysfs/dir.c

+10 −11
Original line number Diff line number Diff line
@@ -30,7 +30,7 @@ static DEFINE_IDA(sysfs_ino_ida); 
 *	Locking:

 *	mutex_lock(sysfs_mutex)

 */

void sysfs_link_sibling(struct sysfs_dirent *sd)

static void sysfs_link_sibling(struct sysfs_dirent *sd)

{

	struct sysfs_dirent *parent_sd = sd->s_parent;
@@ -49,7 +49,7 @@ void sysfs_link_sibling(struct sysfs_dirent *sd) 
 *	Locking:

 *	mutex_lock(sysfs_mutex)

 */

void sysfs_unlink_sibling(struct sysfs_dirent *sd)

static void sysfs_unlink_sibling(struct sysfs_dirent *sd)

{

	struct sysfs_dirent **pos;
@@ -500,6 +500,8 @@ void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) 
		inc_nlink(acxt->parent_inode);



	acxt->cnt++;



	sysfs_link_sibling(sd);

}



/**
@@ -521,7 +523,9 @@ void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) 
 */

void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)

{

	BUG_ON(sd->s_sibling || (sd->s_flags & SYSFS_FLAG_REMOVED));

	BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED);



	sysfs_unlink_sibling(sd);



	sd->s_flags |= SYSFS_FLAG_REMOVED;

	sd->s_sibling = acxt->removed;
@@ -697,10 +701,8 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, 
	/* link in */

	sysfs_addrm_start(&acxt, parent_sd);



	if (!sysfs_find_dirent(parent_sd, name)) {

	if (!sysfs_find_dirent(parent_sd, name))

		sysfs_add_one(&acxt, sd);

		sysfs_link_sibling(sd);

	}



	if (!sysfs_addrm_finish(&acxt)) {

		sysfs_put(sd);
@@ -821,7 +823,6 @@ static void remove_dir(struct sysfs_dirent *sd) 
	struct sysfs_addrm_cxt acxt;



	sysfs_addrm_start(&acxt, sd->s_parent);

	sysfs_unlink_sibling(sd);

	sysfs_remove_one(&acxt, sd);

	sysfs_addrm_finish(&acxt);

}
@@ -846,11 +847,9 @@ static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) 
	while (*pos) {

		struct sysfs_dirent *sd = *pos;



		if (sysfs_type(sd) && sysfs_type(sd) != SYSFS_DIR) {

			*pos = sd->s_sibling;

			sd->s_sibling = NULL;

		if (sysfs_type(sd) && sysfs_type(sd) != SYSFS_DIR)

			sysfs_remove_one(&acxt, sd);

		} else

		else

			pos = &(*pos)->s_sibling;

	}

	sysfs_addrm_finish(&acxt);

fs/sysfs/file.c

+1 −3
Original line number Diff line number Diff line
@@ -405,10 +405,8 @@ int sysfs_add_file(struct sysfs_dirent *dir_sd, const struct attribute *attr, 


	sysfs_addrm_start(&acxt, dir_sd);



	if (!sysfs_find_dirent(dir_sd, attr->name)) {

	if (!sysfs_find_dirent(dir_sd, attr->name))

		sysfs_add_one(&acxt, sd);

		sysfs_link_sibling(sd);

	}



	if (!sysfs_addrm_finish(&acxt)) {

		sysfs_put(sd);

fs/sysfs/inode.c

+4 −13
Original line number Diff line number Diff line
@@ -189,25 +189,16 @@ void sysfs_instantiate(struct dentry *dentry, struct inode *inode) 
int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name)

{

	struct sysfs_addrm_cxt acxt;

	struct sysfs_dirent **pos, *sd;

	struct sysfs_dirent *sd;



	if (!dir_sd)

		return -ENOENT;



	sysfs_addrm_start(&acxt, dir_sd);



	for (pos = &dir_sd->s_children; *pos; pos = &(*pos)->s_sibling) {

		sd = *pos;



		if (!sysfs_type(sd))

			continue;

		if (!strcmp(sd->s_name, name)) {

			*pos = sd->s_sibling;

			sd->s_sibling = NULL;

	sd = sysfs_find_dirent(dir_sd, name);

	if (sd)

		sysfs_remove_one(&acxt, sd);

			break;

		}

	}



	if (sysfs_addrm_finish(&acxt))

		return 0;

fs/sysfs/symlink.c

+1 −3
Original line number Diff line number Diff line
@@ -92,10 +92,8 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char 


	sysfs_addrm_start(&acxt, parent_sd);



	if (!sysfs_find_dirent(parent_sd, name)) {

	if (!sysfs_find_dirent(parent_sd, name))

		sysfs_add_one(&acxt, sd);

		sysfs_link_sibling(sd);

	}



	if (!sysfs_addrm_finish(&acxt)) {

		error = -EEXIST;

fs/sysfs/sysfs.h

+0 −2
Original line number Diff line number Diff line
@@ -56,8 +56,6 @@ extern struct sysfs_dirent sysfs_root; 
extern struct kmem_cache *sysfs_dir_cachep;



extern struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);

extern void sysfs_link_sibling(struct sysfs_dirent *sd);

extern void sysfs_unlink_sibling(struct sysfs_dirent *sd);

extern struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);

extern void sysfs_put_active(struct sysfs_dirent *sd);

extern struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd);

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