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sysfs, kernfs: introduce kernfs_create_dir[_ns]()

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Introduce kernfs interface to manipulate a directory which takes and
returns sysfs_dirents.

create_dir() is renamed to kernfs_create_dir_ns() and its argumantes
and return value are updated.  create_dir() usages are replaced with
kernfs_create_dir_ns() and sysfs_create_subdir() usages are replaced
with kernfs_create_dir().  Dup warnings are handled explicitly by
sysfs users of the kernfs interface.

sysfs_enable_ns() is renamed to kernfs_enable_ns().

This patch doesn't introduce any behavior changes.

v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS.

v3: kernfs_enable_ns() added.

v4: Refreshed on top of "sysfs: drop kobj_ns_type handling, take #2"
    so that this patch removes sysfs_enable_ns().

Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Tejun Heo
2013-11-28 14:54:15 -05:00
committed by Greg Kroah-Hartman
parent 7c6e2d362c
commit 93b2b8e4aa
6 changed files with 54 additions and 37 deletions
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54
fs/sysfs/dir.c
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@@ -666,9 +666,18 @@ struct sysfs_dirent *sysfs_get_dirent_ns(struct sysfs_dirent *parent_sd,
}
EXPORT_SYMBOL_GPL(sysfs_get_dirent_ns);
static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
const char *name, const void *ns,
struct sysfs_dirent **p_sd)
/**
* kernfs_create_dir_ns - create a directory
* @parent: parent in which to create a new directory
* @name: name of the new directory
* @priv: opaque data associated with the new directory
* @ns: optional namespace tag of the directory
*
* Returns the created node on success, ERR_PTR() value on failure.
*/
struct sysfs_dirent *kernfs_create_dir_ns(struct sysfs_dirent *parent,
const char *name, void *priv,
const void *ns)
{
umode_t mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
struct sysfs_addrm_cxt acxt;
@@ -678,28 +687,21 @@ static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
/* allocate */
sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
if (!sd)
return -ENOMEM;
return ERR_PTR(-ENOMEM);
sd->s_ns = ns;
sd->priv = kobj;
sd->priv = priv;
/* link in */
sysfs_addrm_start(&acxt);
rc = sysfs_add_one(&acxt, sd, parent_sd);
rc = __sysfs_add_one(&acxt, sd, parent);
sysfs_addrm_finish(&acxt);
if (rc == 0)
*p_sd = sd;
else
sysfs_put(sd);
if (!rc)
return sd;
return rc;
}
int sysfs_create_subdir(struct kobject *kobj, const char *name,
struct sysfs_dirent **p_sd)
{
return create_dir(kobj, kobj->sd, name, NULL, p_sd);
sysfs_put(sd);
return ERR_PTR(rc);
}
/**
@@ -710,7 +712,6 @@ int sysfs_create_subdir(struct kobject *kobj, const char *name,
int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
{
struct sysfs_dirent *parent_sd, *sd;
int error = 0;
BUG_ON(!kobj);
@@ -722,10 +723,15 @@ int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
if (!parent_sd)
return -ENOENT;
error = create_dir(kobj, parent_sd, kobject_name(kobj), ns, &sd);
if (!error)
kobj->sd = sd;
return error;
sd = kernfs_create_dir_ns(parent_sd, kobject_name(kobj), kobj, ns);
if (IS_ERR(sd)) {
if (PTR_ERR(sd) == -EEXIST)
sysfs_warn_dup(parent_sd, kobject_name(kobj));
return PTR_ERR(sd);
}
kobj->sd = sd;
return 0;
}
static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry,
@@ -1005,14 +1011,14 @@ int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj,
}
/**
* sysfs_enable_ns - enable namespace under a directory
* kernfs_enable_ns - enable namespace under a directory
* @sd: directory of interest, should be empty
*
* This is to be called right after @sd is created to enable namespace
* under it. All children of @sd must have non-NULL namespace tags and
* only the ones which match the super_block's tag will be visible.
*/
void sysfs_enable_ns(struct sysfs_dirent *sd)
void kernfs_enable_ns(struct sysfs_dirent *sd)
{
WARN_ON_ONCE(sysfs_type(sd) != SYSFS_DIR);
WARN_ON_ONCE(!RB_EMPTY_ROOT(&sd->s_dir.children));