Re: [PATCH v2 05/10] btrfs-progs: undelete-subvol: introduce recover_dead_root

2018-05-06 Thread Lu Fengqi 

On Wed, Apr 18, 2018 at 01:16:55PM +0800, Qu Wenruo wrote:



On 2018年03月27日 15:06, Lu Fengqi wrote:

The function will find the root_item specified by the subvol_id,
clear the BTRFS_ROOT_SUBVOL_DEAD flag and set root_refs to one.


Sorry I didn't point it out in btrfs_link_subvol() patch, but at least
to me, refs should only be modified by btrfs_link_subvol(), just like
btrfs_unlink().


This has bothered me a long time. The function create_subvol has set
root_refs to 1 before linking the subvolume in the kernel or
btrfs_progs.

I would like to modify the refs to 1 in btrfs_link_subvol as you said,
regardless of the root_refs of the subvolume is already 1 (only when
link_subvol_for_convert is caller).

--
Thanks,
Lu



Thanks,
Qu



Signed-off-by: Lu Fengqi 
---
 ctree.h   |  1 +
 undelete-subvol.c | 55 +++
 2 files changed, 56 insertions(+)

diff --git a/ctree.h b/ctree.h
index 4bff0b821472..7c0b8150bc4e 100644
--- a/ctree.h
+++ b/ctree.h
@@ -184,6 +184,7 @@ static int btrfs_csum_sizes[] = { 4 };
 #define BTRFS_FT_MAX   9
 
 #define BTRFS_ROOT_SUBVOL_RDONLY	(1ULL << 0)

+#define BTRFS_ROOT_SUBVOL_DEAD (1ULL << 48)
 
 /*

  * the key defines the order in the tree, and so it also defines (optimal)
diff --git a/undelete-subvol.c b/undelete-subvol.c
index 00fcc4895778..781057df2b84 100644
--- a/undelete-subvol.c
+++ b/undelete-subvol.c
@@ -12,6 +12,9 @@
  */
 
 #include "ctree.h"

+#include "transaction.h"
+#include "disk-io.h"
+#include "messages.h"
 
 /*

  * Determines whether the subvolume is intact, according to the drop_progress
@@ -51,3 +54,55 @@ out:
btrfs_release_path();
return ret;
 }
+
+/*
+ * Clear BTRFS_ROOT_SUBVOL_DEAD flag and set the root_refs to one.
+ *
+ * @root   the root of root tree.
+ * @subvol_id  specify the root_item which will be modified.
+ *
+ * Return 0 if no error occurred.
+ */
+static int recover_dead_root(struct btrfs_trans_handle *trans,
+struct btrfs_root *root, u64 subvol_id)
+{
+   struct btrfs_key key;
+   struct btrfs_path path;
+   struct extent_buffer *leaf;
+   struct btrfs_root_item root_item;
+   u64 root_flags;
+   u64 offset;
+   int ret;
+
+   key.objectid = subvol_id;
+   key.type = BTRFS_ROOT_ITEM_KEY;
+   key.offset = 0;
+
+   btrfs_init_path();
+   ret = btrfs_search_slot(trans, root, , , 0, 0);
+   if (ret) {
+   error("couldn't find ROOT_ITEM for %llu failed: %d",
+   subvol_id, ret);
+   goto out;
+   }
+
+   leaf = path.nodes[0];
+
+   offset = btrfs_item_ptr_offset(leaf, path.slots[0]);
+   read_extent_buffer(leaf, _item, offset, sizeof(root_item));
+
+   /* Clear BTRFS_ROOT_SUBVOL_DEAD */
+   root_flags = btrfs_root_flags(_item);
+   btrfs_set_root_flags(_item,
+root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
+
+   /* Increase the refs */
+   btrfs_set_root_refs(_item, 1);
+
+   write_extent_buffer(leaf, _item, offset, sizeof(root_item));
+   btrfs_mark_buffer_dirty(leaf);
+
+out:
+   btrfs_release_path();
+   return ret;
+}






--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: [PATCH v2 05/10] btrfs-progs: undelete-subvol: introduce recover_dead_root

2018-04-17 Thread Qu Wenruo 


On 2018年03月27日 15:06, Lu Fengqi wrote:
> The function will find the root_item specified by the subvol_id,
> clear the BTRFS_ROOT_SUBVOL_DEAD flag and set root_refs to one.

Sorry I didn't point it out in btrfs_link_subvol() patch, but at least
to me, refs should only be modified by btrfs_link_subvol(), just like
btrfs_unlink().

Thanks,
Qu

> 
> Signed-off-by: Lu Fengqi 
> ---
>  ctree.h   |  1 +
>  undelete-subvol.c | 55 
> +++
>  2 files changed, 56 insertions(+)
> 
> diff --git a/ctree.h b/ctree.h
> index 4bff0b821472..7c0b8150bc4e 100644
> --- a/ctree.h
> +++ b/ctree.h
> @@ -184,6 +184,7 @@ static int btrfs_csum_sizes[] = { 4 };
>  #define BTRFS_FT_MAX 9
>  
>  #define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0)
> +#define BTRFS_ROOT_SUBVOL_DEAD   (1ULL << 48)
>  
>  /*
>   * the key defines the order in the tree, and so it also defines (optimal)
> diff --git a/undelete-subvol.c b/undelete-subvol.c
> index 00fcc4895778..781057df2b84 100644
> --- a/undelete-subvol.c
> +++ b/undelete-subvol.c
> @@ -12,6 +12,9 @@
>   */
>  
>  #include "ctree.h"
> +#include "transaction.h"
> +#include "disk-io.h"
> +#include "messages.h"
>  
>  /*
>   * Determines whether the subvolume is intact, according to the drop_progress
> @@ -51,3 +54,55 @@ out:
>   btrfs_release_path();
>   return ret;
>  }
> +
> +/*
> + * Clear BTRFS_ROOT_SUBVOL_DEAD flag and set the root_refs to one.
> + *
> + * @root the root of root tree.
> + * @subvol_idspecify the root_item which will be modified.
> + *
> + * Return 0 if no error occurred.
> + */
> +static int recover_dead_root(struct btrfs_trans_handle *trans,
> +  struct btrfs_root *root, u64 subvol_id)
> +{
> + struct btrfs_key key;
> + struct btrfs_path path;
> + struct extent_buffer *leaf;
> + struct btrfs_root_item root_item;
> + u64 root_flags;
> + u64 offset;
> + int ret;
> +
> + key.objectid = subvol_id;
> + key.type = BTRFS_ROOT_ITEM_KEY;
> + key.offset = 0;
> +
> + btrfs_init_path();
> + ret = btrfs_search_slot(trans, root, , , 0, 0);
> + if (ret) {
> + error("couldn't find ROOT_ITEM for %llu failed: %d",
> + subvol_id, ret);
> + goto out;
> + }
> +
> + leaf = path.nodes[0];
> +
> + offset = btrfs_item_ptr_offset(leaf, path.slots[0]);
> + read_extent_buffer(leaf, _item, offset, sizeof(root_item));
> +
> + /* Clear BTRFS_ROOT_SUBVOL_DEAD */
> + root_flags = btrfs_root_flags(_item);
> + btrfs_set_root_flags(_item,
> +  root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
> +
> + /* Increase the refs */
> + btrfs_set_root_refs(_item, 1);
> +
> + write_extent_buffer(leaf, _item, offset, sizeof(root_item));
> + btrfs_mark_buffer_dirty(leaf);
> +
> +out:
> + btrfs_release_path();
> + return ret;
> +}
> 



signature.asc
Description: OpenPGP digital signature

[PATCH v2 05/10] btrfs-progs: undelete-subvol: introduce recover_dead_root

2018-03-27 Thread Lu Fengqi 
The function will find the root_item specified by the subvol_id,
clear the BTRFS_ROOT_SUBVOL_DEAD flag and set root_refs to one.

Signed-off-by: Lu Fengqi 
---
 ctree.h   |  1 +
 undelete-subvol.c | 55 +++
 2 files changed, 56 insertions(+)

diff --git a/ctree.h b/ctree.h
index 4bff0b821472..7c0b8150bc4e 100644
--- a/ctree.h
+++ b/ctree.h
@@ -184,6 +184,7 @@ static int btrfs_csum_sizes[] = { 4 };
 #define BTRFS_FT_MAX   9
 
 #define BTRFS_ROOT_SUBVOL_RDONLY   (1ULL << 0)
+#define BTRFS_ROOT_SUBVOL_DEAD (1ULL << 48)
 
 /*
  * the key defines the order in the tree, and so it also defines (optimal)
diff --git a/undelete-subvol.c b/undelete-subvol.c
index 00fcc4895778..781057df2b84 100644
--- a/undelete-subvol.c
+++ b/undelete-subvol.c
@@ -12,6 +12,9 @@
  */
 
 #include "ctree.h"
+#include "transaction.h"
+#include "disk-io.h"
+#include "messages.h"
 
 /*
  * Determines whether the subvolume is intact, according to the drop_progress
@@ -51,3 +54,55 @@ out:
btrfs_release_path();
return ret;
 }
+
+/*
+ * Clear BTRFS_ROOT_SUBVOL_DEAD flag and set the root_refs to one.
+ *
+ * @root   the root of root tree.
+ * @subvol_id  specify the root_item which will be modified.
+ *
+ * Return 0 if no error occurred.
+ */
+static int recover_dead_root(struct btrfs_trans_handle *trans,
+struct btrfs_root *root, u64 subvol_id)
+{
+   struct btrfs_key key;
+   struct btrfs_path path;
+   struct extent_buffer *leaf;
+   struct btrfs_root_item root_item;
+   u64 root_flags;
+   u64 offset;
+   int ret;
+
+   key.objectid = subvol_id;
+   key.type = BTRFS_ROOT_ITEM_KEY;
+   key.offset = 0;
+
+   btrfs_init_path();
+   ret = btrfs_search_slot(trans, root, , , 0, 0);
+   if (ret) {
+   error("couldn't find ROOT_ITEM for %llu failed: %d",
+   subvol_id, ret);
+   goto out;
+   }
+
+   leaf = path.nodes[0];
+
+   offset = btrfs_item_ptr_offset(leaf, path.slots[0]);
+   read_extent_buffer(leaf, _item, offset, sizeof(root_item));
+
+   /* Clear BTRFS_ROOT_SUBVOL_DEAD */
+   root_flags = btrfs_root_flags(_item);
+   btrfs_set_root_flags(_item,
+root_flags & ~BTRFS_ROOT_SUBVOL_DEAD);
+
+   /* Increase the refs */
+   btrfs_set_root_refs(_item, 1);
+
+   write_extent_buffer(leaf, _item, offset, sizeof(root_item));
+   btrfs_mark_buffer_dirty(leaf);
+
+out:
+   btrfs_release_path();
+   return ret;
+}
-- 
2.16.2



--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html