Btrfs: virtual address space subset filter

Select chunks which have at least one byte located inside a given
[vstart, vend) virtual address space range.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index c60071a..e86c9e4 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2207,6 +2207,20 @@ static int chunk_drange_filter(struct extent_buffer *leaf,
        return 1;
 }
 
+/* [vstart, vend) */
+static int chunk_vrange_filter(struct extent_buffer *leaf,
+                              struct btrfs_chunk *chunk,
+                              u64 chunk_offset,
+                              struct btrfs_balance_args *bargs)
+{
+       if (chunk_offset < bargs->vend &&
+           chunk_offset + btrfs_chunk_length(leaf, chunk) > bargs->vstart)
+               /* at least part of the chunk is inside this vrange */
+               return 0;
+
+       return 1;
+}
+
 static int should_balance_chunk(struct btrfs_root *root,
                                struct extent_buffer *leaf,
                                struct btrfs_chunk *chunk, u64 chunk_offset)
@@ -2252,6 +2266,12 @@ static int should_balance_chunk(struct btrfs_root *root,
                return 0;
        }
 
+       /* vrange filter */
+       if ((bargs->flags & BTRFS_BALANCE_ARGS_VRANGE) &&
+           chunk_vrange_filter(leaf, chunk, chunk_offset, bargs)) {
+               return 0;
+       }
+
        return 1;
 }
 

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 844b08e..eac26c3 100644 (file)
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -203,6 +203,7 @@ struct map_lookup {
 #define BTRFS_BALANCE_ARGS_USAGE       (1ULL << 1)
 #define BTRFS_BALANCE_ARGS_DEVID       (1ULL << 2)
 #define BTRFS_BALANCE_ARGS_DRANGE      (1ULL << 3)
+#define BTRFS_BALANCE_ARGS_VRANGE      (1ULL << 4)
 
 struct btrfs_balance_args;
 struct btrfs_balance_control {