Now that we have the kobj_completion structure available, let's use it
in ext4.
Note that we aggregate the del/put/wait_for_completion in one
kobj_completion_del_and_wait call. Since the kobject isn't used for
anything while the fs is shutting down and we wait until it's released
before continuing anyway, this is safe.
Signed-off-by: Jeff Mahoney <[email protected]>
---
fs/ext4/ext4.h | 4 ++--
fs/ext4/super.c | 41 ++++++++++++-----------------------------
2 files changed, 14 insertions(+), 31 deletions(-)
--- a/fs/ext4/ext4.h 2013-09-03 11:23:20.054928553 -0400
+++ b/fs/ext4/ext4.h 2013-09-10 13:03:42.794548845 -0400
@@ -30,6 +30,7 @@
#include <linux/blockgroup_lock.h>
#include <linux/percpu_counter.h>
#include <crypto/hash.h>
+#include <linux/kobj_completion.h>
#ifdef __KERNEL__
#include <linux/compat.h>
#endif
@@ -1198,8 +1199,7 @@ struct ext4_sb_info {
struct percpu_counter s_dirtyclusters_counter;
struct blockgroup_lock *s_blockgroup_lock;
struct proc_dir_entry *s_proc;
- struct kobject s_kobj;
- struct completion s_kobj_unregister;
+ struct kobj_completion s_kobjc;
struct super_block *s_sb;
/* Journaling */
--- a/fs/ext4/super.c 2013-09-03 11:23:20.066928375 -0400
+++ b/fs/ext4/super.c 2013-09-10 13:04:16.702156431 -0400
@@ -793,7 +793,8 @@ static void ext4_put_super(struct super_
remove_proc_entry("options", sbi->s_proc);
remove_proc_entry(sb->s_id, ext4_proc_root);
}
- kobject_del(&sbi->s_kobj);
+
+ kobj_completion_del_and_wait(&sbi->s_kobjc);
for (i = 0; i < sbi->s_gdb_count; i++)
brelse(sbi->s_group_desc[i]);
@@ -832,12 +833,6 @@ static void ext4_put_super(struct super_
if (sbi->s_mmp_tsk)
kthread_stop(sbi->s_mmp_tsk);
sb->s_fs_info = NULL;
- /*
- * Now that we are completely done shutting down the
- * superblock, we need to actually destroy the kobject.
- */
- kobject_put(&sbi->s_kobj);
- wait_for_completion(&sbi->s_kobj_unregister);
if (sbi->s_chksum_driver)
crypto_free_shash(sbi->s_chksum_driver);
kfree(sbi->s_blockgroup_lock);
@@ -2622,11 +2617,12 @@ static struct attribute *ext4_feat_attrs
NULL,
};
+#define kobj_to_sb_info(kobj) \
+ container_of(kobj, struct ext4_sb_info, s_kobjc.kc_kobj)
static ssize_t ext4_attr_show(struct kobject *kobj,
struct attribute *attr, char *buf)
{
- struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
- s_kobj);
+ struct ext4_sb_info *sbi = kobj_to_sb_info(kobj);
struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
return a->show ? a->show(a, sbi, buf) : 0;
@@ -2636,19 +2632,12 @@ static ssize_t ext4_attr_store(struct ko
struct attribute *attr,
const char *buf, size_t len)
{
- struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
- s_kobj);
+ struct ext4_sb_info *sbi = kobj_to_sb_info(kobj);
struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
return a->store ? a->store(a, sbi, buf, len) : 0;
}
-static void ext4_sb_release(struct kobject *kobj)
-{
- struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
- s_kobj);
- complete(&sbi->s_kobj_unregister);
-}
static const struct sysfs_ops ext4_attr_ops = {
.show = ext4_attr_show,
@@ -2658,18 +2647,13 @@ static const struct sysfs_ops ext4_attr_
static struct kobj_type ext4_ktype = {
.default_attrs = ext4_attrs,
.sysfs_ops = &ext4_attr_ops,
- .release = ext4_sb_release,
+ .release = kobj_completion_release,
};
-static void ext4_feat_release(struct kobject *kobj)
-{
- complete(&ext4_feat->f_kobj_unregister);
-}
-
static struct kobj_type ext4_feat_ktype = {
.default_attrs = ext4_feat_attrs,
.sysfs_ops = &ext4_attr_ops,
- .release = ext4_feat_release,
+ .release = kobj_completion_release,
};
/*
@@ -4066,10 +4050,9 @@ no_journal:
if (err)
goto failed_mount6;
- sbi->s_kobj.kset = ext4_kset;
- init_completion(&sbi->s_kobj_unregister);
- err = kobject_init_and_add(&sbi->s_kobj, &ext4_ktype, NULL,
- "%s", sb->s_id);
+ sbi->s_kobjc.kc_kobj.kset = ext4_kset;
+ kobj_completion_init(&sbi->s_kobjc, &ext4_ktype);
+ err = kobject_add(&sbi->s_kobjc.kc_kobj, NULL, "%s", sb->s_id);
if (err)
goto failed_mount7;
@@ -4125,7 +4108,7 @@ cantfind_ext4:
#ifdef CONFIG_QUOTA
failed_mount8:
- kobject_del(&sbi->s_kobj);
+ kobj_completion_del_and_wait(&sbi->s_kobjc);
#endif
failed_mount7:
ext4_unregister_li_request(sb);
--
Jeff Mahoney
SUSE Labs
On Tue, Sep 10, 2013 at 01:44:13PM -0400, Jeff Mahoney wrote:
> Now that we have the kobj_completion structure available, let's use it
> in ext4.
>
> Note that we aggregate the del/put/wait_for_completion in one
> kobj_completion_del_and_wait call. Since the kobject isn't used for
> anything while the fs is shutting down and we wait until it's released
> before continuing anyway, this is safe.
>
> Signed-off-by: Jeff Mahoney <[email protected]>
I don't have a huge objection to this, but given that it's not fixing
a bug, and it's not saving _that_ many lines of code, if you want to
run the first patch through Greg's tree (which is fine with me), I
might wait to merge this patch until 3.13, so it's not obvious that
it's worth dealing with the inter-tree dependency, since it
complicates testing on my end.
Does that sound reasonable?
- Ted
On 9/11/13 9:48 PM, Theodore Ts'o wrote:
> On Tue, Sep 10, 2013 at 01:44:13PM -0400, Jeff Mahoney wrote:
>> Now that we have the kobj_completion structure available, let's use it
>> in ext4.
>>
>> Note that we aggregate the del/put/wait_for_completion in one
>> kobj_completion_del_and_wait call. Since the kobject isn't used for
>> anything while the fs is shutting down and we wait until it's released
>> before continuing anyway, this is safe.
>>
>> Signed-off-by: Jeff Mahoney <[email protected]>
>
> I don't have a huge objection to this, but given that it's not fixing
> a bug, and it's not saving _that_ many lines of code, if you want to
> run the first patch through Greg's tree (which is fine with me), I
> might wait to merge this patch until 3.13, so it's not obvious that
> it's worth dealing with the inter-tree dependency, since it
> complicates testing on my end.
>
> Does that sound reasonable?
Works for me. The ext4 case isn't something I'm in a huge rush to get in
-- it was just the most obvious (to me) existing users of the
kobj/completion pair.
-Jeff
--
Jeff Mahoney
SUSE Labs