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>

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 76277d7..b00a3fc 100644 (file)
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -400,22 +400,19 @@ 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);
 }
@@ -424,10 +421,11 @@ 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
@@ -440,27 +438,28 @@ 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;
 
-       if (!!sysfs_ns_type(acxt->parent_sd) != !!sd->s_ns) {
+       if (!!sysfs_ns_type(parent_sd) != !!sd->s_ns) {
                WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
-                       sysfs_ns_type(acxt->parent_sd) ? "required" : "invalid",
-                       acxt->parent_sd->s_name, sd->s_name);
+                       sysfs_ns_type(parent_sd) ? "required" : "invalid",
+                       parent_sd->s_name, sd->s_name);
                return -EINVAL;
        }
 
        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;
@@ -494,10 +493,11 @@ 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
@@ -510,17 +510,18 @@ 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));
@@ -554,7 +555,7 @@ 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;
@@ -577,6 +578,7 @@ 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);
@@ -687,8 +689,8 @@ 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)
@@ -811,7 +813,7 @@ 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);
 }
@@ -831,7 +833,7 @@ 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);

diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 4697019..1656a79 100644 (file)
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -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)

diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c
index 07193d7..364c887 100644 (file)
--- a/fs/sysfs/inode.c
+++ b/fs/sysfs/inode.c
@@ -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)

diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index e651b6c..3fdad86 100644 (file)
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -56,14 +56,14 @@ 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);
        /* Symlinks must be between directories with the same ns_type */
        if (!ns_type ||
            (ns_type == sysfs_ns_type(sd->s_symlink.target_sd->s_parent))) {
                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);
        } else {
                error = -EINVAL;
                WARN(1, KERN_WARNING

diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index 8ffc370..48835f5 100644 (file)
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -132,7 +132,6 @@ do {                                                                \
  * Context structure to be used while adding/removing nodes.
  */
 struct sysfs_addrm_cxt {
-       struct sysfs_dirent     *parent_sd;
        struct sysfs_dirent     *removed;
 };
 
@@ -165,10 +164,11 @@ 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);