btrfs: extend balance filter usage to take minimum and maximum

Similar to the 'limit' filter, we can enhance the 'usage' filter to
accept a range. The change is backward compatible, the range is applied
only in connection with the BTRFS_BALANCE_ARGS_USAGE_RANGE flag.

We don't have a usecase yet, the current syntax has been sufficient. The
enhancement should provide parity with other range-like filters.

Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 8ccbf43..4001585 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -823,8 +823,18 @@ struct btrfs_disk_balance_args {
         */
        __le64 profiles;
 
-       /* usage filter */
-       __le64 usage;
+       /*
+        * usage filter
+        * BTRFS_BALANCE_ARGS_USAGE with a single value means '0..N'
+        * BTRFS_BALANCE_ARGS_USAGE_RANGE - range syntax, min..max
+        */
+       union {
+               __le64 usage;
+               struct {
+                       __le32 usage_min;
+                       __le32 usage_max;
+               };
+       };
 
        /* devid filter */
        __le64 devid;

diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 9f5d167..17ed76d 100644 (file)
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3059,16 +3059,19 @@ static void update_balance_args(struct btrfs_balance_control *bctl)
         * (albeit full) chunks.
         */
        if (!(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+           !(bctl->data.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
            !(bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
                bctl->data.flags |= BTRFS_BALANCE_ARGS_USAGE;
                bctl->data.usage = 90;
        }
        if (!(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+           !(bctl->sys.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
            !(bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
                bctl->sys.flags |= BTRFS_BALANCE_ARGS_USAGE;
                bctl->sys.usage = 90;
        }
        if (!(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE) &&
+           !(bctl->meta.flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
            !(bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT)) {
                bctl->meta.flags |= BTRFS_BALANCE_ARGS_USAGE;
                bctl->meta.usage = 90;
@@ -3124,13 +3127,46 @@ static int chunk_usage_filter(struct btrfs_fs_info *fs_info, u64 chunk_offset,
                              struct btrfs_balance_args *bargs)
 {
        struct btrfs_block_group_cache *cache;
+       u64 chunk_used;
+       u64 user_thresh_min;
+       u64 user_thresh_max;
+       int ret = 1;
+
+       cache = btrfs_lookup_block_group(fs_info, chunk_offset);
+       chunk_used = btrfs_block_group_used(&cache->item);
+
+       if (bargs->usage_min == 0)
+               user_thresh_min = 0;
+       else
+               user_thresh_min = div_factor_fine(cache->key.offset,
+                                       bargs->usage_min);
+
+       if (bargs->usage_max == 0)
+               user_thresh_max = 1;
+       else if (bargs->usage_max > 100)
+               user_thresh_max = cache->key.offset;
+       else
+               user_thresh_max = div_factor_fine(cache->key.offset,
+                                       bargs->usage_max);
+
+       if (user_thresh_min <= chunk_used && chunk_used < user_thresh_max)
+               ret = 0;
+
+       btrfs_put_block_group(cache);
+       return ret;
+}
+
+static int chunk_usage_range_filter(struct btrfs_fs_info *fs_info,
+               u64 chunk_offset, struct btrfs_balance_args *bargs)
+{
+       struct btrfs_block_group_cache *cache;
        u64 chunk_used, user_thresh;
        int ret = 1;
 
        cache = btrfs_lookup_block_group(fs_info, chunk_offset);
        chunk_used = btrfs_block_group_used(&cache->item);
 
-       if (bargs->usage == 0)
+       if (bargs->usage_min == 0)
                user_thresh = 1;
        else if (bargs->usage > 100)
                user_thresh = cache->key.offset;
@@ -3279,6 +3315,9 @@ static int should_balance_chunk(struct btrfs_root *root,
        if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE) &&
            chunk_usage_filter(bctl->fs_info, chunk_offset, bargs)) {
                return 0;
+       } else if ((bargs->flags & BTRFS_BALANCE_ARGS_USAGE_RANGE) &&
+           chunk_usage_range_filter(bctl->fs_info, chunk_offset, bargs)) {
+               return 0;
        }
 
        /* devid filter */

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index a5bf224..2a396cb 100644 (file)
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -382,6 +382,7 @@ struct map_lookup {
 #define BTRFS_BALANCE_ARGS_LIMIT       (1ULL << 5)
 #define BTRFS_BALANCE_ARGS_LIMIT_RANGE (1ULL << 6)
 #define BTRFS_BALANCE_ARGS_STRIPES_RANGE (1ULL << 7)
+#define BTRFS_BALANCE_ARGS_USAGE_RANGE (1ULL << 8)
 
 #define BTRFS_BALANCE_ARGS_MASK                        \
        (BTRFS_BALANCE_ARGS_PROFILES |          \

diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 17a9470..dea8931 100644 (file)
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -206,7 +206,13 @@ struct btrfs_ioctl_feature_flags {
  */
 struct btrfs_balance_args {
        __u64 profiles;
-       __u64 usage;
+       union {
+               __le64 usage;
+               struct {
+                       __le32 usage_min;
+                       __le32 usage_max;
+               };
+       };
        __u64 devid;
        __u64 pstart;
        __u64 pend;