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authorIlya Dryomov <idryomov@gmail.com>2013-08-12 13:33:04 +0200
committerChris Mason <chris.mason@fusionio.com>2013-09-01 14:16:06 +0200
commita1e8780a89ec13217fa1c8f86faf5546110e1402 (patch)
treef39579b432809b689801a31207f76a2efd4499d2 /fs/btrfs
parentBtrfs: add alloc_fs_devices and switch to it (diff)
downloadlinux-a1e8780a89ec13217fa1c8f86faf5546110e1402.tar.xz
linux-a1e8780a89ec13217fa1c8f86faf5546110e1402.zip
Btrfs: rollback btrfs_device fields on umount
It turns out we don't properly rollback in-core btrfs_device state on umount. We zero out ->bdev, ->in_fs_metadata and that's about it. In particular, we don't zero out ->generation, and this can lead to us refusing a mount -- a non-NULL fs_devices->latest_bdev is essential, but btrfs_close_extra_devices will happily assign NULL to ->latest_bdev if the first device on the dev_list happens to be missing and consequently has no bdev attached. This happens because since commit a6b0d5c8 btrfs_close_extra_devices adjusts ->latest_bdev, and in doing that, relies on the ->generation. Fix this, and possibly other problems, by zeroing out everything except for what device_list_add sets, so that a mount right after insmod and 'btrfs dev scan' is no different from any later mount in this respect. Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/volumes.c15
1 files changed, 6 insertions, 9 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index d38065eca7c9..ed685991b2c1 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -674,22 +674,19 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
if (device->can_discard)
fs_devices->num_can_discard--;
- new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
- BUG_ON(!new_device); /* -ENOMEM */
- memcpy(new_device, device, sizeof(*new_device));
+ new_device = btrfs_alloc_device(NULL, &device->devid,
+ device->uuid);
+ BUG_ON(IS_ERR(new_device)); /* -ENOMEM */
/* Safe because we are under uuid_mutex */
if (device->name) {
name = rcu_string_strdup(device->name->str, GFP_NOFS);
- BUG_ON(device->name && !name); /* -ENOMEM */
+ BUG_ON(!name); /* -ENOMEM */
rcu_assign_pointer(new_device->name, name);
}
- new_device->bdev = NULL;
- new_device->writeable = 0;
- new_device->in_fs_metadata = 0;
- new_device->can_discard = 0;
- spin_lock_init(&new_device->io_lock);
+
list_replace_rcu(&device->dev_list, &new_device->dev_list);
+ new_device->fs_devices = device->fs_devices;
call_rcu(&device->rcu, free_device);
}