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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: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tejun Heo 2013-09-18 17:15:35 -04:00 committed by Greg Kroah-Hartman
parent 5b8802143a
commit d69ac5a0bb
5 changed files with 38 additions and 36 deletions
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52
fs/sysfs/dir.c
View File

@ -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);

4
fs/sysfs/file.c
View File

@ -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)

2
fs/sysfs/inode.c
View File

@ -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)

6
fs/sysfs/symlink.c
View File

@ -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)

10
fs/sysfs/sysfs.h
View File

@ -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,
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_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);
void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd);
void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt);