sysfs, kernfs: introduce kernfs[_find_and]_get() and kernfs_put()
Introduce kernfs interface for finding, getting and putting
sysfs_dirents.
* sysfs_find_dirent() is renamed to kernfs_find_ns() and lockdep
assertion for sysfs_mutex is added.
* sysfs_get_dirent_ns() is renamed to kernfs_find_and_get().
* Macro inline dancing around __sysfs_get/put() are removed and
kernfs_get/put() are made proper functions implemented in
fs/sysfs/dir.c.
While the conversions are mostly equivalent, there's one difference -
kernfs_get() doesn't return the input param as its return value. This
change is intentional. While passing through the input increases
writability in some areas, it is unnecessary and has been shown to
cause confusion regarding how the last ref is handled.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 76efeab..b137aa3 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -44,7 +44,7 @@
if (parent->s_flags & SYSFS_FLAG_NS)
sd->s_ns = target->s_ns;
sd->s_symlink.target_sd = target;
- sysfs_get(target); /* ref owned by symlink */
+ kernfs_get(target); /* ref owned by symlink */
sysfs_addrm_start(&acxt);
error = sysfs_add_one(&acxt, sd, parent);
@@ -53,7 +53,7 @@
if (!error)
return sd;
- sysfs_put(sd);
+ kernfs_put(sd);
return ERR_PTR(error);
}
@@ -72,15 +72,17 @@
* sysfs_remove_dir() for details.
*/
spin_lock(&sysfs_symlink_target_lock);
- if (target->sd)
- target_sd = sysfs_get(target->sd);
+ if (target->sd) {
+ target_sd = target->sd;
+ kernfs_get(target_sd);
+ }
spin_unlock(&sysfs_symlink_target_lock);
if (!target_sd)
return -ENOENT;
sd = kernfs_create_link(parent_sd, name, target_sd);
- sysfs_put(target_sd);
+ kernfs_put(target_sd);
if (!IS_ERR(sd))
return 0;
@@ -216,7 +218,7 @@
old_ns = targ->sd->s_ns;
result = -ENOENT;
- sd = sysfs_get_dirent_ns(parent_sd, old, old_ns);
+ sd = kernfs_find_and_get_ns(parent_sd, old, old_ns);
if (!sd)
goto out;
@@ -229,7 +231,7 @@
result = kernfs_rename_ns(sd, parent_sd, new, new_ns);
out:
- sysfs_put(sd);
+ kernfs_put(sd);
return result;
}
EXPORT_SYMBOL_GPL(sysfs_rename_link_ns);