btrfs: add missing device::flush_bio puts

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")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 84d37b4..b5c67dd 100644 (file)
--- 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 @@ again:
                list_del_init(&device->dev_list);
                fs_devices->num_devices--;
                rcu_string_free(device->name);
+               bio_put(device->flush_bio);
                kfree(device);
        }
 
@@ -2353,6 +2358,7 @@ 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;
@@ -2362,6 +2368,7 @@ 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;
@@ -2505,6 +2512,7 @@ error_trans:
        if (trans)
                btrfs_end_transaction(trans);
        rcu_string_free(device->name);
+       bio_put(device->flush_bio);
        kfree(device);
 error:
        blkdev_put(bdev, FMODE_EXCL);
@@ -2571,6 +2579,7 @@ 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;
@@ -6288,6 +6297,7 @@ 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);
                }