1 files changed, 62 insertions, 7 deletions

diff --git a/mkfs/common.c b/mkfs/common.c
index ba47684b..dd5e7ecf 100644
--- a/mkfs/common.c
+++ b/mkfs/common.c
@@ -438,12 +438,6 @@ out:
 	return ret;
 }
 
-u64 btrfs_min_dev_size(u32 nodesize)
-{
-	return 2 * (BTRFS_MKFS_SYSTEM_GROUP_SIZE +
-		    btrfs_min_global_blk_rsv_size(nodesize));
-}
-
 /*
  * Btrfs minimum size calculation is complicated, it should include at least:
  * 1. system group size
@@ -454,11 +448,72 @@ u64 btrfs_min_dev_size(u32 nodesize)
  * To avoid the overkill calculation, (system group + global block rsv) * 2
  * for *EACH* device should be good enough.
  */
-u64 btrfs_min_global_blk_rsv_size(u32 nodesize)
+static u64 btrfs_min_global_blk_rsv_size(u32 nodesize)
 {
 	return (u64)nodesize << 10;
 }
 
+u64 btrfs_min_dev_size(u32 nodesize, int mixed, u64 meta_profile,
+		       u64 data_profile)
+{
+	u64 reserved = 0;
+	u64 meta_size;
+	u64 data_size;
+
+	if (mixed)
+		return 2 * (BTRFS_MKFS_SYSTEM_GROUP_SIZE +
+			    btrfs_min_global_blk_rsv_size(nodesize));
+
+	/*
+	 * Minimal size calculation is complex due to several factors:
+	 * 1) Temporary chunk reuse
+	 *    If specified chunk profile is SINGLE, we can reuse
+	 *    temporary chunks, no need to allocate new chunks.
+	 *
+	 * 2) Different minimal chunk size for different profiles:
+	 *    For initial sys chunk, chunk size is fixed to 4M.
+	 *    For single profile, minimal chunk size is 8M for all.
+	 *    For other profiles, minimal chunk and stripe size ranges from 8M
+	 *    to 64M.
+	 *
+	 * To calculate it a little easier, here we assume we don't reuse any
+	 * temporary chunk, and calculate the size completely by ourselves.
+	 *
+	 * Temporary chunks sizes are always fixed:
+	 * One initial sys chunk, one SINGLE meta, and one SINGLE data.
+	 * The latter two are all 8M, accroding to @calc_size of
+	 * btrfs_alloc_chunk().
+	 */
+	reserved += BTRFS_MKFS_SYSTEM_GROUP_SIZE + SZ_8M * 2;
+
+	/*
+	 * For real chunks, we need to select different sizes:
+	 * For SINGLE, it's still fixed to 8M (@calc_size).
+	 * For other profiles, refer to max(@min_stripe_size, @calc_size).
+	 *
+	 * And use the stripe size to calculate its physical used space.
+	 */
+	if (meta_profile & BTRFS_BLOCK_GROUP_PROFILE_MASK)
+		meta_size = SZ_8M + SZ_32M;
+	else
+		meta_size = SZ_8M + SZ_8M;
+	/* For DUP/metadata,  2 stripes on one disk */
+	if (meta_profile & BTRFS_BLOCK_GROUP_DUP)
+		meta_size *= 2;
+	reserved += meta_size;
+
+	if (data_profile & BTRFS_BLOCK_GROUP_PROFILE_MASK)
+		data_size = SZ_64M;
+	else
+		data_size = SZ_8M;
+	/* For DUP/data,  2 stripes on one disk */
+	if (data_profile & BTRFS_BLOCK_GROUP_DUP)
+		data_size *= 2;
+	reserved += data_size;
+
+	return reserved;
+}
+
 #define isoctal(c)	(((c) & ~7) == '0')
 
 static inline void translate(char *f, char *t)