Re: [PATCH 1/2] btrfs: Don't search devid for every verify_one_dev_extent() call

[Anand Jain]

On 1/30/19 3:39 PM, Qu Wenruo wrote:

verify_one_dev_extent() will call btrfs_find_device() for each dev
extent, this waste some CPU time just searching the devices list.


Move the search one level up, into the btrfs_verify_dev_extents(), so
for each device we only call btrfs_find_device() once.


This does not apply on misc-next. Looks like this patch's branch is 
missing the seed fix.

Looks good.

Reviewed-by: Anand Jain <anand.j...@oracle.com>


Signed-off-by: Qu Wenruo <w...@suse.com>
---
  fs/btrfs/volumes.c | 26 ++++++++++++++++----------
  1 file changed, 16 insertions(+), 10 deletions(-)

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 2576b1a379c9..8e932d7d2fe6 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -7761,13 +7761,14 @@ static u64 calc_stripe_length(u64 type, u64 chunk_len, 
int num_stripes)
  }
  
  static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
-                                u64 chunk_offset, u64 devid,
-                                u64 physical_offset, u64 physical_len)
+                                struct btrfs_device *dev,
+                                u64 chunk_offset, u64 physical_offset,
+                                u64 physical_len)
  {
        struct extent_map_tree *em_tree = &fs_info->mapping_tree.map_tree;
        struct extent_map *em;
        struct map_lookup *map;
-       struct btrfs_device *dev;
+       u64 devid = dev->devid;
        u64 stripe_len;
        bool found = false;
        int ret = 0;
@@ -7819,12 +7820,6 @@ static int verify_one_dev_extent(struct btrfs_fs_info 
*fs_info,
        }
  
  	/* Make sure no dev extent is beyond device bondary */
-       dev = btrfs_find_device(fs_info, devid, NULL, NULL);
-       if (!dev) {
-               btrfs_err(fs_info, "failed to find devid %llu", devid);
-               ret = -EUCLEAN;
-               goto out;
-       }
        if (physical_offset + physical_len > dev->disk_total_bytes) {
                btrfs_err(fs_info,
  "dev extent devid %llu physical offset %llu len %llu is beyond device boundary 
%llu",
@@ -7874,6 +7869,7 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info 
*fs_info)
  {
        struct btrfs_path *path;
        struct btrfs_root *root = fs_info->dev_root;
+       struct btrfs_device *device = NULL;
        struct btrfs_key key;
        u64 prev_devid = 0;
        u64 prev_dev_ext_end = 0;
@@ -7917,6 +7913,16 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info 
*fs_info)
                devid = key.objectid;
                physical_offset = key.offset;
  
+		if (!device || devid != device->devid) {
+                       device = btrfs_find_device(fs_info, devid, NULL, NULL);
+                       if (!device) {
+                               btrfs_err(fs_info, "failed to find devid %llu",
+                                         devid);
+                               ret = -EUCLEAN;
+                               goto out;
+                       }
+               }
+
                dext = btrfs_item_ptr(leaf, slot, struct btrfs_dev_extent);
                chunk_offset = btrfs_dev_extent_chunk_offset(leaf, dext);
                physical_len = btrfs_dev_extent_length(leaf, dext);
@@ -7930,7 +7936,7 @@ int btrfs_verify_dev_extents(struct btrfs_fs_info 
*fs_info)
                        goto out;
                }
  
-		ret = verify_one_dev_extent(fs_info, chunk_offset, devid,
+               ret = verify_one_dev_extent(fs_info, device, chunk_offset,
                                            physical_offset, physical_len);
                if (ret < 0)
                        goto out;