[PATCH 05/12] btrfs-progs: factor out decide_stripe_size()

[Naohiro Aota]

Factor out decide_stripe_size() from btrfs_alloc_chunk(). This new function
calculates the actual stripe size to allocate and decides the size of a
stripe (ctl->calc_size).

This commit has no functional changes.

Signed-off-by: Naohiro Aota <naohiro.a...@wdc.com>
---
 kernel-shared/volumes.c | 44 +++++++++++++++++++++++++++++++----------
 1 file changed, 34 insertions(+), 10 deletions(-)

diff --git a/kernel-shared/volumes.c b/kernel-shared/volumes.c
index 1ca71a9bc430..95b42eab846d 100644
--- a/kernel-shared/volumes.c
+++ b/kernel-shared/volumes.c
@@ -1087,6 +1087,37 @@ static void init_alloc_chunk_ctl(struct btrfs_fs_info 
*info,
        }
 }
 
+static int decide_stripe_size_regular(struct alloc_chunk_ctl *ctl)
+{
+       u64 chunk_size = chunk_bytes_by_type(ctl->type, ctl->calc_size, ctl);
+
+       if (chunk_size > ctl->max_chunk_size) {
+               ctl->calc_size = ctl->max_chunk_size;
+               ctl->calc_size /= ctl->num_stripes;
+               ctl->calc_size /= ctl->stripe_len;
+               ctl->calc_size *= ctl->stripe_len;
+       }
+       /* we don't want tiny stripes */
+       ctl->calc_size = max_t(u64, ctl->calc_size, ctl->min_stripe_size);
+
+       /* Align to the stripe length */
+       ctl->calc_size /= ctl->stripe_len;
+       ctl->calc_size *= ctl->stripe_len;
+
+       return 0;
+}
+
+static int decide_stripe_size(struct btrfs_fs_info *info,
+                             struct alloc_chunk_ctl *ctl)
+{
+       switch (info->fs_devices->chunk_alloc_policy) {
+       case BTRFS_CHUNK_ALLOC_REGULAR:
+               return decide_stripe_size_regular(ctl);
+       default:
+               BUG();
+       }
+}
+
 int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
                      struct btrfs_fs_info *info, u64 *start,
                      u64 *num_bytes, u64 type)
@@ -1121,17 +1152,10 @@ int btrfs_alloc_chunk(struct btrfs_trans_handle *trans,
                return -ENOSPC;
 
 again:
-       if (chunk_bytes_by_type(type, ctl.calc_size, &ctl) > 
ctl.max_chunk_size) {
-               ctl.calc_size = ctl.max_chunk_size;
-               ctl.calc_size /= ctl.num_stripes;
-               ctl.calc_size /= ctl.stripe_len;
-               ctl.calc_size *= ctl.stripe_len;
-       }
-       /* we don't want tiny stripes */
-       ctl.calc_size = max_t(u64, ctl.calc_size, ctl.min_stripe_size);
+       ret = decide_stripe_size(info, &ctl);
+       if (ret < 0)
+               return ret;
 
-       ctl.calc_size /= ctl.stripe_len;
-       ctl.calc_size *= ctl.stripe_len;
        INIT_LIST_HEAD(&private_devs);
        cur = dev_list->next;
        index = 0;
-- 
2.31.1