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Message-ID: <20071029142427.GA21930@bigserver.hohndel.org>
Date: Mon, 29 Oct 2007 07:24:27 -0700
From: Dirk Hohndel <hohndel@...ux.intel.com>
To: Cornelia Huck <cornelia.huck@...ibm.com>
Cc: Andries Brouwer <aeb@....nl>, Al Viro <viro@....linux.org.uk>,
Jens Axboe <jens.axboe@...cle.com>,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] add_partition silently ignored errors
On Mon, Oct 29, 2007 at 02:06:57PM +0100, Cornelia Huck wrote:
> On Mon, 29 Oct 2007 05:22:11 -0700,
> Dirk Hohndel <hohndel@...ux.intel.com> wrote:
>
> <only commenting on the kobject part...>
>
> > @@ -390,20 +390,31 @@ void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len,
> > p->kobj.parent = &disk->kobj;
> > p->kobj.ktype = &ktype_part;
> > kobject_init(&p->kobj);
> > - kobject_add(&p->kobj);
> > + if (kobject_add(&p->kobj))
> > + return -1;
> > if (!disk->part_uevent_suppress)
> > kobject_uevent(&p->kobj, KOBJ_ADD);
> > - sysfs_create_link(&p->kobj, &block_subsys.kobj, "subsystem");
> > + if(sysfs_create_link(&p->kobj, &block_subsys.kobj, "subsystem")) {
> > + kobject_del(&p->kobj);
> > + kfree(p);
> > + return -1;
> > + }
>
>
> - This is missing a KOBJ_DEL uevent if you did a KOBJ_ADD uevent.
Completely missed that one.
> - Calling kfree() after you already registered the kobject via
> kobject_add() is wrong, since someone else might already have obtained
> a reference. You must drop your reference after kobject_del() and let
> the release mechanism take care of it.
Good point.
> <I think I'm having some kind of deja vu, since it seems I've already
> pointed that out a couple of times to different people :) >
>
> > if (flags & ADDPART_FLAG_WHOLEDISK) {
> > static struct attribute addpartattr = {
> > .name = "whole_disk",
> > .mode = S_IRUSR | S_IRGRP | S_IROTH,
> > };
> >
> > - sysfs_create_file(&p->kobj, &addpartattr);
> > + if (sysfs_create_file(&p->kobj, &addpartattr)) {
> > + kobject_del(&p->kobj);
> > + kfree(p);
> > + return -1;
> > + }
>
> Same here. You should probably also delete the link you created above.
Yep, fixed that as well.
How about the new patch below?
Signed-off-by: Dirk Hohndel <hohndel@...ux.intel.com>
---
block/ioctl.c | 5 ++++-
fs/partitions/check.c | 28 ++++++++++++++++++++++------
include/linux/genhd.h | 2 +-
3 files changed, 27 insertions(+), 8 deletions(-)
diff --git a/block/ioctl.c b/block/ioctl.c
index 52d6385..bb3933e 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -61,7 +61,10 @@ static int blkpg_ioctl(struct block_device *bdev, struct blkpg_ioctl_arg __user
}
}
/* all seems OK */
- add_partition(disk, part, start, length, ADDPART_FLAG_NONE);
+ if (add_partition(disk, part, start, length, ADDPART_FLAG_NONE)) {
+ mutex_unlock(&bdev->bd_mutex);
+ return -EBUSY;
+ }
mutex_unlock(&bdev->bd_mutex);
return 0;
case BLKPG_DEL_PARTITION:
diff --git a/fs/partitions/check.c b/fs/partitions/check.c
index 722e12e..6bdf855 100644
--- a/fs/partitions/check.c
+++ b/fs/partitions/check.c
@@ -368,13 +368,13 @@ void delete_partition(struct gendisk *disk, int part)
kobject_put(&p->kobj);
}
-void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len, int flags)
+int add_partition(struct gendisk *disk, int part, sector_t start, sector_t len, int flags)
{
struct hd_struct *p;
p = kzalloc(sizeof(*p), GFP_KERNEL);
if (!p)
- return;
+ return -1;
p->start_sect = start;
p->nr_sects = len;
@@ -390,20 +390,33 @@ void add_partition(struct gendisk *disk, int part, sector_t start, sector_t len,
p->kobj.parent = &disk->kobj;
p->kobj.ktype = &ktype_part;
kobject_init(&p->kobj);
- kobject_add(&p->kobj);
+ if (kobject_add(&p->kobj))
+ return -1;
if (!disk->part_uevent_suppress)
kobject_uevent(&p->kobj, KOBJ_ADD);
- sysfs_create_link(&p->kobj, &block_subsys.kobj, "subsystem");
+ if(sysfs_create_link(&p->kobj, &block_subsys.kobj, "subsystem"))
+ goto out_cleanup;
if (flags & ADDPART_FLAG_WHOLEDISK) {
static struct attribute addpartattr = {
.name = "whole_disk",
.mode = S_IRUSR | S_IRGRP | S_IROTH,
};
- sysfs_create_file(&p->kobj, &addpartattr);
+ if (sysfs_create_file(&p->kobj, &addpartattr)) {
+ sysfs_remove_link (&p->kobj, "subsystem");
+ goto out_cleanup;
+ }
}
partition_sysfs_add_subdir(p);
disk->part[part-1] = p;
+
+ return 0;
+
+out_cleanup:
+ if (!disk->part_uevent_suppress)
+ kobject_uevent(&p->kobj, KOBJ_REMOVE);
+ kobject_del(&p->kobj);
+ return -1;
}
static char *make_block_name(struct gendisk *disk)
@@ -554,8 +567,11 @@ int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
if (from + size > get_capacity(disk)) {
printk(" %s: p%d exceeds device capacity\n",
disk->disk_name, p);
+ return -EBUSY;
+ }
+ if(add_partition(disk, p, from, size, state->parts[p].flags)) {
+ return -EBUSY;
}
- add_partition(disk, p, from, size, state->parts[p].flags);
#ifdef CONFIG_BLK_DEV_MD
if (state->parts[p].flags & ADDPART_FLAG_RAID)
md_autodetect_dev(bdev->bd_dev+p);
diff --git a/include/linux/genhd.h b/include/linux/genhd.h
index a47b802..ae6af2c 100644
--- a/include/linux/genhd.h
+++ b/include/linux/genhd.h
@@ -414,7 +414,7 @@ struct unixware_disklabel {
char *disk_name (struct gendisk *hd, int part, char *buf);
extern int rescan_partitions(struct gendisk *disk, struct block_device *bdev);
-extern void add_partition(struct gendisk *, int, sector_t, sector_t, int);
+extern int add_partition(struct gendisk *, int, sector_t, sector_t, int);
extern void delete_partition(struct gendisk *, int);
extern void printk_all_partitions(void);
--
gitgui.0.8.4.g8d863
-
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