On 2018年03月27日 15:06, Lu Fengqi wrote: > The function default will traverse the all orphan items on the tree root, > and recover the all intact subvolumes. If subvol_id is specified, then only > the corresponding subvolume will be recovered. > > Signed-off-by: Lu Fengqi <lufq.f...@cn.fujitsu.com> > --- > v2: add subvol_id argumenta to specify subvol_id instead of recovering > all subvolumes. > > undelete-subvol.c | 70 > +++++++++++++++++++++++++++++++++++++++++++++++++++++++ > undelete-subvol.h | 2 ++ > 2 files changed, 72 insertions(+) > > diff --git a/undelete-subvol.c b/undelete-subvol.c > index 9243e35545c5..5b494ca086ab 100644 > --- a/undelete-subvol.c > +++ b/undelete-subvol.c > @@ -15,6 +15,7 @@ > #include "transaction.h" > #include "disk-io.h" > #include "messages.h" > +#include "undelete-subvol.h" > > /* > * Determines whether the subvolume is intact, according to the drop_progress > @@ -182,3 +183,72 @@ static int link_subvol_to_lostfound(struct btrfs_root > *root, u64 subvol_id) > out: > return ret; > } > + > +/* > + * Traverse all orphan items on the root tree, restore them to the lost+found > + * directory if the corresponding subvolumes are still intact left on the > disk. > + * > + * @root the root of the root tree.
Same comment here.
> + * @subvol_id if not set to 0, skip other subvolumes and only recover
> the
> + * subvolume specified by @subvol_id.
> + *
> + * Return 0 if no error occurred even if no subvolume was recovered.
> + */
> +int btrfs_undelete_intact_subvols(struct btrfs_root *root, u64 subvol_id)
I prefer to remove the word "_intact".
> +{
> + struct btrfs_key key;
> + struct btrfs_path path;
> + u64 found_count = 0;
> + u64 recovered_count = 0;
> + int ret = 0;
> +
> + key.objectid = BTRFS_ORPHAN_OBJECTID;
> + key.type = BTRFS_ORPHAN_ITEM_KEY;
> + key.offset = subvol_id ? subvol_id + 1 : (u64)-1;
> +
> + btrfs_init_path(&path);
I would prefer to do btrfs_search_slot() here, and then use
btrfs_previous_item() to iterate, other than calling btrfs_search_slot()
several times.
> + while (subvol_id != key.offset) {
> + ret = btrfs_search_slot(NULL, root, &key, &path, 0, 0);
> + if (ret < 0) {
> + error("search ORPHAN_ITEM for %llu failed.\n",
> + key.offset);
> + break;
> + }
> +
> + path.slots[0]--;
Btrfs_previous_item() is much better here.
Especially when above btrfs_search_slot() could return 0 (key found) and
path.slots[0] could be 0.
That's also the reason why I prefer btrfs_search_slot() then
btrfs_previous_item() in the loop.
Thanks,
Qu
> + btrfs_item_key_to_cpu(path.nodes[0], &key, path.slots[0]);
> +
> + btrfs_release_path(&path);
> +
> + /* No more BTRFS_ORPHAN_ITEM, so we don't need to continue. */
> + if (key.type != BTRFS_ORPHAN_ITEM_KEY) {
> + ret = 0;
> + break;
> + }
> +
> + /* If subvol_id is non-zero, skip other deleted subvolume. */
> + if (subvol_id && subvol_id != key.offset) {
> + ret = -ENOENT;
> + break;
> + }
> +
> + if (!is_subvol_intact(root, key.offset))
> + continue;
> +
> + /* Here we can confirm there is an intact subvolume. */
> + found_count++;
> + ret = link_subvol_to_lostfound(root, key.offset);
> + if (ret == 0) {
> + recovered_count++;
> + printf(
> + "Recovered subvolume %llu to lost+found successfully.\n",
> + key.offset);
> + }
> +
> + }
> +
> + printf("Found %llu subvols left intact\n", found_count);
> + printf("Recovered %llu subvols\n", found_count);
> +
> + return ret;
> +}
> diff --git a/undelete-subvol.h b/undelete-subvol.h
> index 7cfd100cce37..f773210c46fe 100644
> --- a/undelete-subvol.h
> +++ b/undelete-subvol.h
> @@ -14,4 +14,6 @@
> #ifndef __BTRFS_UNDELETE_SUBVOLUME_H__
> #define __BTRFS_UNDELETE_SUBVOLUME_H__
>
> +int btrfs_undelete_intact_subvols(struct btrfs_root *root, u64 subvol_id);
> +
> #endif
>
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