On Wed, Apr 18, 2018 at 01:28:23PM +0800, Qu Wenruo wrote:
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.fnst@xxxxxxxxxxxxxx>
---
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.
Make sense.
+ * @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".
I also like the shorter function name.
+{
+ 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.
This loop will perform some additions and deletions of the items on the
tree, so we have to call btrfs_search_slot in the loop.
+ 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.
Make sense.
--
Thanks,
Lu
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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