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Diffstat (limited to 'fs/sysfs/symlink.c')
-rw-r--r--fs/sysfs/symlink.c50
1 files changed, 28 insertions, 22 deletions
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 2dd4507d9edd..3ae3f1bf1a09 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -33,13 +33,15 @@ static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd,
BUG_ON(!name || !parent_sd);
- /* target->sd can go away beneath us but is protected with
- * sysfs_assoc_lock. Fetch target_sd from it.
+ /*
+ * We don't own @target and it may be removed at any time.
+ * Synchronize using sysfs_symlink_target_lock. See
+ * sysfs_remove_dir() for details.
*/
- spin_lock(&sysfs_assoc_lock);
+ spin_lock(&sysfs_symlink_target_lock);
if (target->sd)
target_sd = sysfs_get(target->sd);
- spin_unlock(&sysfs_assoc_lock);
+ spin_unlock(&sysfs_symlink_target_lock);
error = -ENOENT;
if (!target_sd)
@@ -52,18 +54,18 @@ static int sysfs_do_create_link_sd(struct sysfs_dirent *parent_sd,
ns_type = sysfs_ns_type(parent_sd);
if (ns_type)
- sd->s_ns = target->ktype->namespace(target);
+ sd->s_ns = target_sd->s_ns;
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
@@ -155,11 +157,17 @@ void sysfs_delete_link(struct kobject *kobj, struct kobject *targ,
const char *name)
{
const void *ns = NULL;
- spin_lock(&sysfs_assoc_lock);
+
+ /*
+ * We don't own @target and it may be removed at any time.
+ * Synchronize using sysfs_symlink_target_lock. See
+ * sysfs_remove_dir() for details.
+ */
+ spin_lock(&sysfs_symlink_target_lock);
if (targ->sd && sysfs_ns_type(kobj->sd))
ns = targ->sd->s_ns;
- spin_unlock(&sysfs_assoc_lock);
- sysfs_hash_and_remove(kobj->sd, ns, name);
+ spin_unlock(&sysfs_symlink_target_lock);
+ sysfs_hash_and_remove(kobj->sd, name, ns);
}
/**
@@ -176,24 +184,25 @@ void sysfs_remove_link(struct kobject *kobj, const char *name)
else
parent_sd = kobj->sd;
- sysfs_hash_and_remove(parent_sd, NULL, name);
+ sysfs_hash_and_remove(parent_sd, name, NULL);
}
EXPORT_SYMBOL_GPL(sysfs_remove_link);
/**
- * sysfs_rename_link - rename symlink in object's directory.
+ * sysfs_rename_link_ns - rename symlink in object's directory.
* @kobj: object we're acting for.
* @targ: object we're pointing to.
* @old: previous name of the symlink.
* @new: new name of the symlink.
+ * @new_ns: new namespace of the symlink.
*
* A helper function for the common rename symlink idiom.
*/
-int sysfs_rename_link(struct kobject *kobj, struct kobject *targ,
- const char *old, const char *new)
+int sysfs_rename_link_ns(struct kobject *kobj, struct kobject *targ,
+ const char *old, const char *new, const void *new_ns)
{
struct sysfs_dirent *parent_sd, *sd = NULL;
- const void *old_ns = NULL, *new_ns = NULL;
+ const void *old_ns = NULL;
int result;
if (!kobj)
@@ -205,7 +214,7 @@ int sysfs_rename_link(struct kobject *kobj, struct kobject *targ,
old_ns = targ->sd->s_ns;
result = -ENOENT;
- sd = sysfs_get_dirent(parent_sd, old_ns, old);
+ sd = sysfs_get_dirent_ns(parent_sd, old, old_ns);
if (!sd)
goto out;
@@ -215,16 +224,13 @@ int sysfs_rename_link(struct kobject *kobj, struct kobject *targ,
if (sd->s_symlink.target_sd->s_dir.kobj != targ)
goto out;
- if (sysfs_ns_type(parent_sd))
- new_ns = targ->ktype->namespace(targ);
-
- result = sysfs_rename(sd, parent_sd, new_ns, new);
+ result = sysfs_rename(sd, parent_sd, new, new_ns);
out:
sysfs_put(sd);
return result;
}
-EXPORT_SYMBOL_GPL(sysfs_rename_link);
+EXPORT_SYMBOL_GPL(sysfs_rename_link_ns);
static int sysfs_get_target_path(struct sysfs_dirent *parent_sd,
struct sysfs_dirent *target_sd, char *path)