Commit d69ac5a0 authored by Tejun Heo's avatar Tejun Heo Committed by Greg Kroah-Hartman
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sysfs: remove sysfs_addrm_cxt->parent_sd 



sysfs_addrm_start/finish() enclose sysfs_dirent additions and
deletions and sysfs_addrm_cxt is used to record information necessary
to finish the operations.  Currently, sysfs_addrm_start() takes
@parent_sd, records it in sysfs_addrm_cxt, and assumes that all
operations in the block are performed under that @parent_sd.

This assumption has been fine until now but we want to make some
operations behave recursively and, while having @parent_sd recorded in
sysfs_addrm_cxt doesn't necessarily prevents that, it becomes
confusing.

This patch removes sysfs_addrm_cxt->parent_sd and makes
sysfs_add_one() take an explicit @parent_sd parameter.  Note that
sysfs_remove_one() doesn't need the extra argument as its parent is
always known from the target @sd.

While at it, add __acquires/releases() notations to
sysfs_addrm_start/finish() respectively.

This patch doesn't make any functional difference.

Signed-off-by: default avatarTejun Heo <tj@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 5b880214

fs/sysfs/dir.c

+27 −25
Original line number Diff line number Diff line
@@ -406,22 +406,19 @@ struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type) 
/**

 *	sysfs_addrm_start - prepare for sysfs_dirent add/remove

 *	@acxt: pointer to sysfs_addrm_cxt to be used

 *	@parent_sd: parent sysfs_dirent

 *

 *	This function is called when the caller is about to add or

 *	remove sysfs_dirent under @parent_sd.  This function acquires

 *	sysfs_mutex.  @acxt is used to keep and pass context to

 *	other addrm functions.

 *	This function is called when the caller is about to add or remove

 *	sysfs_dirent.  This function acquires sysfs_mutex.  @acxt is used

 *	to keep and pass context to other addrm functions.

 *

 *	LOCKING:

 *	Kernel thread context (may sleep).  sysfs_mutex is locked on

 *	return.

 */

void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,

		       struct sysfs_dirent *parent_sd)

void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt)

	__acquires(sysfs_mutex)

{

	memset(acxt, 0, sizeof(*acxt));

	acxt->parent_sd = parent_sd;



	mutex_lock(&sysfs_mutex);

}
@@ -430,10 +427,11 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, 
 *	__sysfs_add_one - add sysfs_dirent to parent without warning

 *	@acxt: addrm context to use

 *	@sd: sysfs_dirent to be added

 *	@parent_sd: the parent sysfs_dirent to add @sd to

 *

 *	Get @acxt->parent_sd and set sd->s_parent to it and increment

 *	nlink of parent inode if @sd is a directory and link into the

 *	children list of the parent.

 *	Get @parent_sd and set @sd->s_parent to it and increment nlink of

 *	the parent inode if @sd is a directory and link into the children

 *	list of the parent.

 *

 *	This function should be called between calls to

 *	sysfs_addrm_start() and sysfs_addrm_finish() and should be
@@ -446,20 +444,21 @@ void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt, 
 *	0 on success, -EEXIST if entry with the given name already

 *	exists.

 */

int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)

int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,

		    struct sysfs_dirent *parent_sd)

{

	struct sysfs_inode_attrs *ps_iattr;

	int ret;



	sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns);

	sd->s_parent = sysfs_get(acxt->parent_sd);

	sd->s_parent = sysfs_get(parent_sd);



	ret = sysfs_link_sibling(sd);

	if (ret)

		return ret;



	/* Update timestamps on the parent */

	ps_iattr = acxt->parent_sd->s_iattr;

	ps_iattr = parent_sd->s_iattr;

	if (ps_iattr) {

		struct iattr *ps_iattrs = &ps_iattr->ia_iattr;

		ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
@@ -493,10 +492,11 @@ static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) 
 *	sysfs_add_one - add sysfs_dirent to parent

 *	@acxt: addrm context to use

 *	@sd: sysfs_dirent to be added

 *	@parent_sd: the parent sysfs_dirent to add @sd to

 *

 *	Get @acxt->parent_sd and set sd->s_parent to it and increment

 *	nlink of parent inode if @sd is a directory and link into the

 *	children list of the parent.

 *	Get @parent_sd and set @sd->s_parent to it and increment nlink of

 *	the parent inode if @sd is a directory and link into the children

 *	list of the parent.

 *

 *	This function should be called between calls to

 *	sysfs_addrm_start() and sysfs_addrm_finish() and should be
@@ -509,17 +509,18 @@ static char *sysfs_pathname(struct sysfs_dirent *sd, char *path) 
 *	0 on success, -EEXIST if entry with the given name already

 *	exists.

 */

int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)

int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,

		  struct sysfs_dirent *parent_sd)

{

	int ret;



	ret = __sysfs_add_one(acxt, sd);

	ret = __sysfs_add_one(acxt, sd, parent_sd);

	if (ret == -EEXIST) {

		char *path = kzalloc(PATH_MAX, GFP_KERNEL);

		WARN(1, KERN_WARNING

		     "sysfs: cannot create duplicate filename '%s'\n",

		     (path == NULL) ? sd->s_name

				    : (sysfs_pathname(acxt->parent_sd, path),

				    : (sysfs_pathname(parent_sd, path),

				       strlcat(path, "/", PATH_MAX),

				       strlcat(path, sd->s_name, PATH_MAX),

				       path));
@@ -553,7 +554,7 @@ void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) 
	sysfs_unlink_sibling(sd);



	/* Update timestamps on the parent */

	ps_iattr = acxt->parent_sd->s_iattr;

	ps_iattr = sd->s_parent->s_iattr;

	if (ps_iattr) {

		struct iattr *ps_iattrs = &ps_iattr->ia_iattr;

		ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
@@ -576,6 +577,7 @@ void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) 
 *	sysfs_mutex is released.

 */

void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)

	__releases(sysfs_mutex)

{

	/* release resources acquired by sysfs_addrm_start() */

	mutex_unlock(&sysfs_mutex);
@@ -678,8 +680,8 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd, 
	sd->s_dir.kobj = kobj;



	/* link in */

	sysfs_addrm_start(&acxt, parent_sd);

	rc = sysfs_add_one(&acxt, sd);

	sysfs_addrm_start(&acxt);

	rc = sysfs_add_one(&acxt, sd, parent_sd);

	sysfs_addrm_finish(&acxt);



	if (rc == 0)
@@ -772,7 +774,7 @@ static void remove_dir(struct sysfs_dirent *sd) 
{

	struct sysfs_addrm_cxt acxt;



	sysfs_addrm_start(&acxt, sd->s_parent);

	sysfs_addrm_start(&acxt);

	sysfs_remove_one(&acxt, sd);

	sysfs_addrm_finish(&acxt);

}
@@ -792,7 +794,7 @@ static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd) 
		return;



	pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);

	sysfs_addrm_start(&acxt, dir_sd);

	sysfs_addrm_start(&acxt);

	pos = rb_first(&dir_sd->s_dir.children);

	while (pos) {

		struct sysfs_dirent *sd = to_sysfs_dirent(pos);

fs/sysfs/file.c

+2 −2
Original line number Diff line number Diff line
@@ -502,8 +502,8 @@ int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd, 
	sd->s_attr.attr = (void *)attr;

	sysfs_dirent_init_lockdep(sd);



	sysfs_addrm_start(&acxt, dir_sd);

	rc = sysfs_add_one(&acxt, sd);

	sysfs_addrm_start(&acxt);

	rc = sysfs_add_one(&acxt, sd, dir_sd);

	sysfs_addrm_finish(&acxt);



	if (rc)

fs/sysfs/inode.c

+1 −1
Original line number Diff line number Diff line
@@ -326,7 +326,7 @@ int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name, 
		return -ENOENT;

	}



	sysfs_addrm_start(&acxt, dir_sd);

	sysfs_addrm_start(&acxt);



	sd = sysfs_find_dirent(dir_sd, name, ns);

	if (sd)

fs/sysfs/symlink.c

+3 −3
Original line number Diff line number Diff line
@@ -53,11 +53,11 @@ static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd, 
	sd->s_symlink.target_sd = target_sd;

	target_sd = NULL;	/* reference is now owned by the symlink */



	sysfs_addrm_start(&acxt, parent_sd);

	sysfs_addrm_start(&acxt);

	if (warn)

		error = sysfs_add_one(&acxt, sd);

		error = sysfs_add_one(&acxt, sd, parent_sd);

	else

		error = __sysfs_add_one(&acxt, sd);

		error = __sysfs_add_one(&acxt, sd, parent_sd);

	sysfs_addrm_finish(&acxt);



	if (error)

fs/sysfs/sysfs.h

+5 −5
Original line number Diff line number Diff line
@@ -120,7 +120,6 @@ do { \ 
 * Context structure to be used while adding/removing nodes.

 */

struct sysfs_addrm_cxt {

	struct sysfs_dirent	*parent_sd;

	struct sysfs_dirent	*removed;

};
@@ -154,10 +153,11 @@ extern const struct inode_operations sysfs_dir_inode_operations; 
struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd);

struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd);

void sysfs_put_active(struct sysfs_dirent *sd);

void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,

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);

int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,

		  struct sysfs_dirent *parent_sd);

int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);

int 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);

void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);

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