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| author | Jeff Mahoney <jeffm@suse.com> | 2014-05-27 12:59:57 -0400 |
|---|---|---|
| committer | Chris Mason <clm@fb.com> | 2014-06-09 17:21:01 -0700 |
| commit | c1895442be01c58449e3bf9272f22062a670e08f (patch) | |
| tree | 8a09bb69c59dfdbcff5869cb82490487ec0bf86e /fs/btrfs/sysfs.c | |
| parent | 7e3ae33efad1490d01040f552ef50e58ed6376ca (diff) | |
| download | lwn-c1895442be01c58449e3bf9272f22062a670e08f.tar.gz lwn-c1895442be01c58449e3bf9272f22062a670e08f.zip | |
btrfs: allocate raid type kobjects dynamically
We are currently allocating space_info objects in an array when we
allocate space_info. When a user does something like:
# btrfs balance start -mconvert=raid1 -dconvert=raid1 /mnt
# btrfs balance start -mconvert=single -dconvert=single /mnt -f
# btrfs balance start -mconvert=raid1 -dconvert=raid1 /
We can end up with memory corruption since the kobject hasn't
been reinitialized properly and the name pointer was left set.
The rationale behind allocating them statically was to avoid
creating a separate kobject container that just contained the
raid type. It used the index in the array to determine the index.
Ultimately, though, this wastes more memory than it saves in all
but the most complex scenarios and introduces kobject lifetime
questions.
This patch allocates the kobjects dynamically instead. Note that
we also remove the kobject_get/put of the parent kobject since
kobject_add and kobject_del do that internally.
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reported-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <clm@fb.com>
Diffstat (limited to 'fs/btrfs/sysfs.c')
| -rw-r--r-- | fs/btrfs/sysfs.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/btrfs/sysfs.c b/fs/btrfs/sysfs.c index c0dfda5644f2..df39458f1487 100644 --- a/fs/btrfs/sysfs.c +++ b/fs/btrfs/sysfs.c @@ -254,6 +254,7 @@ static ssize_t global_rsv_reserved_show(struct kobject *kobj, BTRFS_ATTR(global_rsv_reserved, 0444, global_rsv_reserved_show); #define to_space_info(_kobj) container_of(_kobj, struct btrfs_space_info, kobj) +#define to_raid_kobj(_kobj) container_of(_kobj, struct raid_kobject, kobj) static ssize_t raid_bytes_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf); @@ -266,7 +267,7 @@ static ssize_t raid_bytes_show(struct kobject *kobj, { struct btrfs_space_info *sinfo = to_space_info(kobj->parent); struct btrfs_block_group_cache *block_group; - int index = kobj - sinfo->block_group_kobjs; + int index = to_raid_kobj(kobj)->raid_type; u64 val = 0; down_read(&sinfo->groups_sem); @@ -288,7 +289,7 @@ static struct attribute *raid_attributes[] = { static void release_raid_kobj(struct kobject *kobj) { - kobject_put(kobj->parent); + kfree(to_raid_kobj(kobj)); } struct kobj_type btrfs_raid_ktype = { |