Btrfs: Add mount -o ssd, which includes optimizations for seek free storage
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 2c569b4..b69a466 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1431,6 +1431,19 @@
data = BTRFS_BLOCK_GROUP_MIXED;
}
+ /* for SSD, cluster allocations together as much as possible */
+ if (btrfs_test_opt(root, SSD)) {
+ if (!data) {
+ if (root->fs_info->last_alloc)
+ hint_byte = root->fs_info->last_alloc;
+ else {
+ hint_byte = hint_byte &
+ ~((u64)BTRFS_BLOCK_GROUP_SIZE - 1);
+ empty_size += 16 * 1024 * 1024;
+ }
+ }
+ }
+
search_end = min(search_end,
btrfs_super_total_bytes(&info->super_copy));
if (hint_byte) {
@@ -1456,6 +1469,19 @@
}
search_start = find_search_start(root, &block_group, search_start,
total_needed, data);
+
+ if (!data && btrfs_test_opt(root, SSD) && info->last_alloc &&
+ search_start != info->last_alloc) {
+ info->last_alloc = 0;
+ if (!empty_size) {
+ empty_size += 16 * 1024 * 1024;
+ total_needed += empty_size;
+ }
+ search_start = find_search_start(root, &block_group,
+ search_start, total_needed,
+ data);
+ }
+
search_start = stripe_align(root, search_start);
cached_start = search_start;
btrfs_init_path(path);
@@ -1610,6 +1636,8 @@
error:
btrfs_release_path(root, path);
btrfs_free_path(path);
+ if (btrfs_test_opt(root, SSD) && !ret && !data)
+ info->last_alloc = ins->objectid + ins->offset;
return ret;
}
/*
@@ -1778,7 +1806,8 @@
buf->start, buf->start + buf->len - 1,
EXTENT_CSUM, GFP_NOFS);
buf->flags |= EXTENT_CSUM;
- btrfs_set_buffer_defrag(buf);
+ if (!btrfs_test_opt(root, SSD))
+ btrfs_set_buffer_defrag(buf);
trans->blocks_used++;
return buf;
}