Btrfs: make raid attr array more readable

PATCH In review Miao Xie 2 participants 3 messages Jan 16, 2013 – Jan 17, 2013 Btrfs file system

lore

Share & tools

lore

Miao Xie

author

2013-01-16 11:32 UTC #0 lore raw

PATCH 2/2 Btrfs: make raid attr array more readable

As the title said, this patch just make raid attr array more readable.

Cc Liu Bo <[email protected]>

Signed-off-by Miao Xie <[email protected]>

---
 fs/btrfs/ctree.h       | 10 +++++++++-
 fs/btrfs/extent-tree.c | 22 +++++++++-------------
 fs/btrfs/volumes.c     | 47 +++++++++++++++++++++++++++++++++++++++++------
 3 files changed, 59 insertions(+), 20 deletions(-)

fs/btrfs/ctree.h +9 -1

index 9ee099f..541ce9a 100644
@@ -953,7 +953,15 @@ struct btrfs_dev_replace_item {
 #define BTRFS_BLOCK_GROUP_DUP		(1ULL << 5)
 #define BTRFS_BLOCK_GROUP_RAID10	(1ULL << 6)
 #define BTRFS_BLOCK_GROUP_RESERVED	BTRFS_AVAIL_ALLOC_BIT_SINGLE
-#define BTRFS_NR_RAID_TYPES		5
+
+enum btrfs_raid_types {
+	BTRFS_RAID_RAID10,
+	BTRFS_RAID_RAID1,
+	BTRFS_RAID_DUP,
+	BTRFS_RAID_RAID0,
+	BTRFS_RAID_SINGLE,
+	BTRFS_NR_RAID_TYPES
+};
 
 #define BTRFS_BLOCK_GROUP_TYPE_MASK	(BTRFS_BLOCK_GROUP_DATA |    \
 					 BTRFS_BLOCK_GROUP_SYSTEM |  \

fs/btrfs/extent-tree.c +9 ~~-13~~

index e68585d..6de0621 100644
@@ -5547,20 +5547,16 @@ wait_block_group_cache_done(struct btrfs_block_group_cache *cache)
 
 int __get_raid_index(u64 flags)
 {
-	int index;
-
 	if (flags & BTRFS_BLOCK_GROUP_RAID10)
-		index = 0;
+		return BTRFS_RAID_RAID10;
 	else if (flags & BTRFS_BLOCK_GROUP_RAID1)
-		index = 1;
+		return BTRFS_RAID_RAID1;
 	else if (flags & BTRFS_BLOCK_GROUP_DUP)
-		index = 2;
+		return BTRFS_RAID_DUP;
 	else if (flags & BTRFS_BLOCK_GROUP_RAID0)
-		index = 3;
+		return BTRFS_RAID_RAID0;
 	else
-		index = 4;
-
-	return index;
+		return BTRFS_RAID_SINGLE;
 }
 
 static int get_block_group_index(struct btrfs_block_group_cache *cache)

@@ -7520,16 +7516,16 @@ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr)
 		index = get_block_group_index(block_group);
 	}
 
-	if (index == 0) {
+	if (index == BTRFS_RAID_RAID10) {
 		dev_min = 4;
 		/* Divide by 2 */
 		min_free >>= 1;
-	} else if (index == 1) {
+	} else if (index == BTRFS_RAID_RAID1) {
 		dev_min = 2;
-	} else if (index == 2) {
+	} else if (index == BTRFS_RAID_DUP) {
 		/* Multiply by 2 */
 		min_free <<= 1;
-	} else if (index == 3) {
+	} else if (index == BTRFS_RAID_RAID0) {
 		dev_min = fs_devices->rw_devices;
 		do_div(min_free, dev_min);
 	}

fs/btrfs/volumes.c +41 -6

54 lines not on this page · raw message

Signature · 1 line

1.7.11.7

David Sterba

2013-01-16 14:04 UTC #1 lore raw

Quoted 1 line · Miao Xie

As the title said, this patch just make raid attr array more readable.

Nice cleanup, thanks.

fs/btrfs/volumes.c static int btrfs_cmp_device_info(const void *a, const void *b) · line 3499

Quoted 12 lines

fs/btrfs/volumes.c +4 -1

@@ -3492,13 +3492,48 @@ static int btrfs_cmp_device_info(const void *a, const void *b)
 }
 
 struct btrfs_raid_attr btrfs_raid_array[BTRFS_NR_RAID_TYPES] = {
-	{ 1, 1, 2, 2, 2, 2 /* raid1 */ },
 
+	[BTRFS_RAID_RAID1] = {
+		.sub_stripes	= 1,
+		.dev_stripes	= 1,
+		.devs_max	= 2,

Unrelated, but I'm curious why is this set to 2 (and was before)? This will give preference to the same 2 devices as long as there's space, so the allocator will not spread the data over the device set. I'd expect the same behaviour as in RAID10 profile here.

fs/btrfs/volumes.c static int btrfs_cmp_device_info(const void *a, const void *b) · line 3510

Quoted 4 lines

fs/btrfs/volumes.c +4 -0

+		.devs_min	= 2,
+		.devs_increment	= 2,
+		.ncopies	= 2,
+	},

david

Miao Xie

author

2013-01-17 05:38 UTC #2 lore raw

PATCH v2 2/2 Btrfs: make raid attr array more readable

The current code of raid attr arry is hard to understand and it is easy to introduce some problem if we modify the array. So I changed it and made it more readable.