On 11/01/2017 01:44 AM, David Sterba wrote:
This fixes potential bio leaks, in several error paths. Unfortunatelly
the device structure freeing is opencoded in many places and I missed
them when introducing the flush_bio.
Most of the time, devices get freed through call_rcu(..., free_device),
so it at least it's not that easy to hit the leak, but it's still
possible through the path that frees stale devices.
Fixes: e0ae99941423 ("btrfs: preallocate device flush bio")
Signed-off-by: David Sterba <dsterba@xxxxxxxx>
Reviewed-by: Anand Jain <anand.jain@xxxxxxxxxx>
Thanks, Anand
---
fs/btrfs/volumes.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index ea8b20839ac0..08fb4b5609b7 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -189,6 +189,7 @@ static void free_fs_devices(struct btrfs_fs_devices *fs_devices)
struct btrfs_device, dev_list);
list_del(&device->dev_list);
rcu_string_free(device->name);
+ bio_put(device->flush_bio);
kfree(device);
}
kfree(fs_devices);
@@ -578,6 +579,7 @@ static void btrfs_free_stale_device(struct btrfs_device *cur_dev)
fs_devs->num_devices--;
list_del(&dev->dev_list);
rcu_string_free(dev->name);
+ bio_put(dev->flush_bio);
kfree(dev);
}
break;
@@ -630,6 +632,7 @@ static noinline int device_list_add(const char *path,
name = rcu_string_strdup(path, GFP_NOFS);
if (!name) {
+ bio_put(device->flush_bio);
kfree(device);
return -ENOMEM;
}
@@ -742,6 +745,7 @@ static struct btrfs_fs_devices *clone_fs_devices(struct btrfs_fs_devices *orig)
name = rcu_string_strdup(orig_dev->name->str,
GFP_KERNEL);
if (!name) {
+ bio_put(device->flush_bio);
kfree(device);
goto error;
}
@@ -807,6 +811,7 @@ void btrfs_close_extra_devices(struct btrfs_fs_devices *fs_devices, int step)
list_del_init(&device->dev_list);
fs_devices->num_devices--;
rcu_string_free(device->name);
+ bio_put(device->flush_bio);
kfree(device);
}
@@ -2337,6 +2342,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
name = rcu_string_strdup(device_path, GFP_KERNEL);
if (!name) {
+ bio_put(device->flush_bio);
kfree(device);
ret = -ENOMEM;
goto error;
@@ -2346,6 +2352,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
rcu_string_free(device->name);
+ bio_put(device->flush_bio);
kfree(device);
ret = PTR_ERR(trans);
goto error;
@@ -2489,6 +2496,7 @@ int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *device_path
if (trans)
btrfs_end_transaction(trans);
rcu_string_free(device->name);
+ bio_put(device->flush_bio);
kfree(device);
error:
blkdev_put(bdev, FMODE_EXCL);
@@ -2555,6 +2563,7 @@ int btrfs_init_dev_replace_tgtdev(struct btrfs_fs_info *fs_info,
name = rcu_string_strdup(device_path, GFP_KERNEL);
if (!name) {
+ bio_put(device->flush_bio);
kfree(device);
ret = -ENOMEM;
goto error;
@@ -6271,6 +6280,7 @@ struct btrfs_device *btrfs_alloc_device(struct btrfs_fs_info *fs_info,
ret = find_next_devid(fs_info, &tmp);
if (ret) {
+ bio_put(dev->flush_bio);
kfree(dev);
return ERR_PTR(ret);
}
--
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