[PATCH] btrfs: Make btrfs_finish_chunk_alloc private to block-group.c

[PATCH] btrfs: Make btrfs_finish_chunk_alloc private to block-group.c

[Nikolay Borisov]

One of the final things that must be done to add a new chunk is
allocating its device extents and inserting them in the extent tree.
This is currently done in btrfs_finish_chunk_alloc whose name isn't very
informative. What's more this functino is only used in block-group.c but
is defined as public. There isn't anything special about it that would
warrant it being defined in volumes.c.

Just move btrfs_finish_chunk_alloc and alloc_chunk_dev_extent to
block-group.c, make the former static and it to alloc_chunk_dev_extents.
The new name is a lot more explicit about the purpose of the function.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>

---
 fs/btrfs/block-group.c | 98 +++++++++++++++++++++++++++++++++++++++++-
 fs/btrfs/volumes.c     | 92 ---------------------------------------
 fs/btrfs/volumes.h     |  2 -
 3 files changed, 96 insertions(+), 96 deletions(-)

diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
index c557327b4545..2e133ee61d83 100644
--- a/fs/btrfs/block-group.c
+++ b/fs/btrfs/block-group.c
@@ -2236,6 +2236,100 @@ static int insert_block_group_item(struct btrfs_trans_handle *trans,
 	return btrfs_insert_item(trans, root, &key, &bgi, sizeof(bgi));
 }
 
+
+static int alloc_dev_extent(struct btrfs_trans_handle *trans,
+			    struct btrfs_device *device, u64 chunk_offset,
+			    u64 start, u64 num_bytes)
+{
+	int ret;
+	struct btrfs_path *path;
+	struct btrfs_fs_info *fs_info = device->fs_info;
+	struct btrfs_root *root = fs_info->dev_root;
+	struct btrfs_dev_extent *extent;
+	struct extent_buffer *leaf;
+	struct btrfs_key key;
+
+	WARN_ON(!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state));
+	WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
+	path = btrfs_alloc_path();
+	if (!path)
+		return -ENOMEM;
+
+	key.objectid = device->devid;
+	key.offset = start;
+	key.type = BTRFS_DEV_EXTENT_KEY;
+	ret = btrfs_insert_empty_item(trans, root, path, &key,
+				      sizeof(*extent));
+	if (ret)
+		goto out;
+
+	leaf = path->nodes[0];
+	extent = btrfs_item_ptr(leaf, path->slots[0],
+				struct btrfs_dev_extent);
+	btrfs_set_dev_extent_chunk_tree(leaf, extent,
+					BTRFS_CHUNK_TREE_OBJECTID);
+	btrfs_set_dev_extent_chunk_objectid(leaf, extent,
+					    BTRFS_FIRST_CHUNK_TREE_OBJECTID);
+	btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
+
+	btrfs_set_dev_extent_length(leaf, extent, num_bytes);
+	btrfs_mark_buffer_dirty(leaf);
+out:
+	btrfs_free_path(path);
+	return ret;
+}
+
+
+/*
+ * This function belongs to phase 2.
+ *
+ * See the comment at btrfs_chunk_alloc() for details about the chunk allocation
+ * phases.
+ */
+static int alloc_chunk_dev_extents(struct btrfs_trans_handle *trans,
+				   u64 chunk_offset, u64 chunk_size)
+{
+	struct btrfs_fs_info *fs_info = trans->fs_info;
+	struct btrfs_device *device;
+	struct extent_map *em;
+	struct map_lookup *map;
+	u64 dev_offset;
+	u64 stripe_size;
+	int i;
+	int ret = 0;
+
+	em = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size);
+	if (IS_ERR(em))
+		return PTR_ERR(em);
+
+	map = em->map_lookup;
+	stripe_size = em->orig_block_len;
+
+	/*
+	 * Take the device list mutex to prevent races with the final phase of
+	 * a device replace operation that replaces the device object associated
+	 * with the map's stripes, because the device object's id can change
+	 * at any time during that final phase of the device replace operation
+	 * (dev-replace.c:btrfs_dev_replace_finishing()), so we could grab the
+	 * replaced device and then see it with an ID of BTRFS_DEV_REPLACE_DEVID,
+	 * resulting in persisting a device extent item with such ID.
+	 */
+	mutex_lock(&fs_info->fs_devices->device_list_mutex);
+	for (i = 0; i < map->num_stripes; i++) {
+		device = map->stripes[i].dev;
+		dev_offset = map->stripes[i].physical;
+
+		ret = alloc_dev_extent(trans, device, chunk_offset, dev_offset,
+				       stripe_size);
+		if (ret)
+			break;
+	}
+	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
+
+	free_extent_map(em);
+	return ret;
+}
+
 /*
  * This function, btrfs_create_pending_block_groups(), belongs to the phase 2 of
  * chunk allocation.
@@ -2270,8 +2364,8 @@ void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans)
 			if (ret)
 				btrfs_abort_transaction(trans, ret);
 		}
-		ret = btrfs_finish_chunk_alloc(trans, block_group->start,
-					block_group->length);
+		ret = alloc_chunk_dev_extents(trans, block_group->start,
+					      block_group->length);
 		if (ret)
 			btrfs_abort_transaction(trans, ret);
 		add_block_group_free_space(trans, block_group);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c6c14315b1c9..f820c32f4a0d 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -1758,48 +1758,6 @@ static int btrfs_free_dev_extent(struct btrfs_trans_handle *trans,
 	return ret;
 }
 
-static int btrfs_alloc_dev_extent(struct btrfs_trans_handle *trans,
-				  struct btrfs_device *device,
-				  u64 chunk_offset, u64 start, u64 num_bytes)
-{
-	int ret;
-	struct btrfs_path *path;
-	struct btrfs_fs_info *fs_info = device->fs_info;
-	struct btrfs_root *root = fs_info->dev_root;
-	struct btrfs_dev_extent *extent;
-	struct extent_buffer *leaf;
-	struct btrfs_key key;
-
-	WARN_ON(!test_bit(BTRFS_DEV_STATE_IN_FS_METADATA, &device->dev_state));
-	WARN_ON(test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state));
-	path = btrfs_alloc_path();
-	if (!path)
-		return -ENOMEM;
-
-	key.objectid = device->devid;
-	key.offset = start;
-	key.type = BTRFS_DEV_EXTENT_KEY;
-	ret = btrfs_insert_empty_item(trans, root, path, &key,
-				      sizeof(*extent));
-	if (ret)
-		goto out;
-
-	leaf = path->nodes[0];
-	extent = btrfs_item_ptr(leaf, path->slots[0],
-				struct btrfs_dev_extent);
-	btrfs_set_dev_extent_chunk_tree(leaf, extent,
-					BTRFS_CHUNK_TREE_OBJECTID);
-	btrfs_set_dev_extent_chunk_objectid(leaf, extent,
-					    BTRFS_FIRST_CHUNK_TREE_OBJECTID);
-	btrfs_set_dev_extent_chunk_offset(leaf, extent, chunk_offset);
-
-	btrfs_set_dev_extent_length(leaf, extent, num_bytes);
-	btrfs_mark_buffer_dirty(leaf);
-out:
-	btrfs_free_path(path);
-	return ret;
-}
-
 static u64 find_next_chunk(struct btrfs_fs_info *fs_info)
 {
 	struct extent_map_tree *em_tree;
@@ -5462,56 +5420,6 @@ struct btrfs_block_group *btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
 	return block_group;
 }
 
-/*
- * This function, btrfs_finish_chunk_alloc(), belongs to phase 2.
- *
- * See the comment at btrfs_chunk_alloc() for details about the chunk allocation
- * phases.
- */
-int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
-			     u64 chunk_offset, u64 chunk_size)
-{
-	struct btrfs_fs_info *fs_info = trans->fs_info;
-	struct btrfs_device *device;
-	struct extent_map *em;
-	struct map_lookup *map;
-	u64 dev_offset;
-	u64 stripe_size;
-	int i;
-	int ret = 0;
-
-	em = btrfs_get_chunk_map(fs_info, chunk_offset, chunk_size);
-	if (IS_ERR(em))
-		return PTR_ERR(em);
-
-	map = em->map_lookup;
-	stripe_size = em->orig_block_len;
-
-	/*
-	 * Take the device list mutex to prevent races with the final phase of
-	 * a device replace operation that replaces the device object associated
-	 * with the map's stripes, because the device object's id can change
-	 * at any time during that final phase of the device replace operation
-	 * (dev-replace.c:btrfs_dev_replace_finishing()), so we could grab the
-	 * replaced device and then see it with an ID of BTRFS_DEV_REPLACE_DEVID,
-	 * resulting in persisting a device extent item with such ID.
-	 */
-	mutex_lock(&fs_info->fs_devices->device_list_mutex);
-	for (i = 0; i < map->num_stripes; i++) {
-		device = map->stripes[i].dev;
-		dev_offset = map->stripes[i].physical;
-
-		ret = btrfs_alloc_dev_extent(trans, device, chunk_offset,
-					     dev_offset, stripe_size);
-		if (ret)
-			break;
-	}
-	mutex_unlock(&fs_info->fs_devices->device_list_mutex);
-
-	free_extent_map(em);
-	return ret;
-}
-
 /*
  * This function, btrfs_chunk_alloc_add_chunk_item(), typically belongs to the
  * phase 1 of chunk allocation. It belongs to phase 2 only when allocating system
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 55a8ba244716..70c749eee3ad 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -508,8 +508,6 @@ int btrfs_is_parity_mirror(struct btrfs_fs_info *fs_info,
 			   u64 logical, u64 len);
 unsigned long btrfs_full_stripe_len(struct btrfs_fs_info *fs_info,
 				    u64 logical);
-int btrfs_finish_chunk_alloc(struct btrfs_trans_handle *trans,
-			     u64 chunk_offset, u64 chunk_size);
 int btrfs_chunk_alloc_add_chunk_item(struct btrfs_trans_handle *trans,
 				     struct btrfs_block_group *bg);
 int btrfs_remove_chunk(struct btrfs_trans_handle *trans, u64 chunk_offset);
-- 
2.17.1

Re: [PATCH] btrfs: Make btrfs_finish_chunk_alloc private to block-group.c

[Johannes Thumshirn]

On 02/07/2021 14:48, Nikolay Borisov wrote:
> One of the final things that must be done to add a new chunk is
> allocating its device extents and inserting them in the extent tree.
> This is currently done in btrfs_finish_chunk_alloc whose name isn't very
> informative. What's more this functino is only used in block-group.c bu                      function ~^                                 but ~^

> is defined as public. There isn't anything special about it that would
> warrant it being defined in volumes.c.
> 
> Just move btrfs_finish_chunk_alloc and alloc_chunk_dev_extent to
> block-group.c, make the former static and it to alloc_chunk_dev_extents.
                                   rename ~^


> The new name is a lot more explicit about the purpose of the function.
> 
> Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> 
> ---
>  fs/btrfs/block-group.c | 98 +++++++++++++++++++++++++++++++++++++++++-
>  fs/btrfs/volumes.c     | 92 ---------------------------------------
>  fs/btrfs/volumes.h     |  2 -
>  3 files changed, 96 insertions(+), 96 deletions(-)
> 
> diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
> index c557327b4545..2e133ee61d83 100644
> --- a/fs/btrfs/block-group.c
> +++ b/fs/btrfs/block-group.c
> @@ -2236,6 +2236,100 @@ static int insert_block_group_item(struct btrfs_trans_handle *trans,
>  	return btrfs_insert_item(trans, root, &key, &bgi, sizeof(bgi));
>  }
>  
> +

double newline

Re: [PATCH] btrfs: Make btrfs_finish_chunk_alloc private to block-group.c

[Filipe Manana]

On Fri, Jul 2, 2021 at 2:21 PM Johannes Thumshirn
<Johannes.Thumshirn@wdc.com> wrote:
>
> On 02/07/2021 14:48, Nikolay Borisov wrote:
> > One of the final things that must be done to add a new chunk is
> > allocating its device extents and inserting them in the extent tree.
> > This is currently done in btrfs_finish_chunk_alloc whose name isn't very
> > informative. What's more this functino is only used in block-group.c bu                      function ~^                                 but ~^
>
> > is defined as public. There isn't anything special about it that would
> > warrant it being defined in volumes.c.
> >
> > Just move btrfs_finish_chunk_alloc and alloc_chunk_dev_extent to
> > block-group.c, make the former static and it to alloc_chunk_dev_extents.
>                                    rename ~^
>
>
> > The new name is a lot more explicit about the purpose of the function.

I find the new name confusing as well.

alloc_chunk_dev_extents() suggests it's allocating device extents, but
it's not, all it does is insert the device extent items into the
devices btree.
Allocation of extents happened in phase 1, through btrfs_alloc_chunk().

Thanks.

> >
> > Signed-off-by: Nikolay Borisov <nborisov@suse.com>
> >
> > ---
> >  fs/btrfs/block-group.c | 98 +++++++++++++++++++++++++++++++++++++++++-
> >  fs/btrfs/volumes.c     | 92 ---------------------------------------
> >  fs/btrfs/volumes.h     |  2 -
> >  3 files changed, 96 insertions(+), 96 deletions(-)
> >
> > diff --git a/fs/btrfs/block-group.c b/fs/btrfs/block-group.c
> > index c557327b4545..2e133ee61d83 100644
> > --- a/fs/btrfs/block-group.c
> > +++ b/fs/btrfs/block-group.c
> > @@ -2236,6 +2236,100 @@ static int insert_block_group_item(struct btrfs_trans_handle *trans,
> >       return btrfs_insert_item(trans, root, &key, &bgi, sizeof(bgi));
> >  }
> >
> > +
>
> double newline
>


-- 
Filipe David Manana,

“Whether you think you can, or you think you can't — you're right.”

Re: [PATCH] btrfs: Make btrfs_finish_chunk_alloc private to block-group.c

[Nikolay Borisov]

On 2.07.21 г. 17:12, Filipe Manana wrote:
> On Fri, Jul 2, 2021 at 2:21 PM Johannes Thumshirn
> <Johannes.Thumshirn@wdc.com> wrote:
>>
>> On 02/07/2021 14:48, Nikolay Borisov wrote:
>>> One of the final things that must be done to add a new chunk is
>>> allocating its device extents and inserting them in the extent tree.
>>> This is currently done in btrfs_finish_chunk_alloc whose name isn't very
>>> informative. What's more this functino is only used in block-group.c bu                      function ~^                                 but ~^
>>
>>> is defined as public. There isn't anything special about it that would
>>> warrant it being defined in volumes.c.
>>>
>>> Just move btrfs_finish_chunk_alloc and alloc_chunk_dev_extent to
>>> block-group.c, make the former static and it to alloc_chunk_dev_extents.
>>                                    rename ~^
>>
>>
>>> The new name is a lot more explicit about the purpose of the function.
> 
> I find the new name confusing as well.
> 
> alloc_chunk_dev_extents() suggests it's allocating device extents, but
> it's not, all it does is insert the device extent items into the
> devices btree.
> Allocation of extents happened in phase 1, through btrfs_alloc_chunk().

The reason I give it plural name is because the inner function is called
alloc_dev_extent hence I gave the top level functino a plural form. I'm
fine simply renaming both functions to insert_dev_extent[s] respectively?

<snip>

Re: [PATCH] btrfs: Make btrfs_finish_chunk_alloc private to block-group.c

[Filipe Manana]

On Fri, Jul 2, 2021 at 4:03 PM Nikolay Borisov <nborisov@suse.com> wrote:
>
>
>
> On 2.07.21 г. 17:12, Filipe Manana wrote:
> > On Fri, Jul 2, 2021 at 2:21 PM Johannes Thumshirn
> > <Johannes.Thumshirn@wdc.com> wrote:
> >>
> >> On 02/07/2021 14:48, Nikolay Borisov wrote:
> >>> One of the final things that must be done to add a new chunk is
> >>> allocating its device extents and inserting them in the extent tree.
> >>> This is currently done in btrfs_finish_chunk_alloc whose name isn't very
> >>> informative. What's more this functino is only used in block-group.c bu                      function ~^                                 but ~^
> >>
> >>> is defined as public. There isn't anything special about it that would
> >>> warrant it being defined in volumes.c.
> >>>
> >>> Just move btrfs_finish_chunk_alloc and alloc_chunk_dev_extent to
> >>> block-group.c, make the former static and it to alloc_chunk_dev_extents.
> >>                                    rename ~^
> >>
> >>
> >>> The new name is a lot more explicit about the purpose of the function.
> >
> > I find the new name confusing as well.
> >
> > alloc_chunk_dev_extents() suggests it's allocating device extents, but
> > it's not, all it does is insert the device extent items into the
> > devices btree.
> > Allocation of extents happened in phase 1, through btrfs_alloc_chunk().
>
> The reason I give it plural name is because the inner function is called
> alloc_dev_extent hence I gave the top level functino a plural form. I'm
> fine simply renaming both functions to insert_dev_extent[s] respectively?

Yes, that's much better. Either "insert" or "add".

Also please fix the changelog:

"One of the final things that must be done to add a new chunk is
allocating its device extents and inserting them in the extent tree."

The allocation part is not done in this phase, as I mentioned earlier,
and the insertion is in the devices btree and not in the extent btree.

Thanks.

>
> <snip>



-- 
Filipe David Manana,

“Whether you think you can, or you think you can't — you're right.”