From 1883251686b1de012e909c4459deceff1f95a96c Mon Sep 17 00:00:00 2001
From: Chris Mason <chris.mason@oracle.com>
Date: Fri, 30 Nov 2007 11:30:24 -0500
Subject: [PATCH] Add simple stripe size parameter

---
 ctree.h       | 15 +++++++++++++++
 disk-io.c     |  1 +
 extent-tree.c | 27 ++++++++++++++++++++-------
 mkfs.c        | 11 ++++++++---
 4 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/ctree.h b/ctree.h
index 2f55b15..fb972c1 100644
--- a/ctree.h
+++ b/ctree.h
@@ -122,6 +122,7 @@ struct btrfs_super_block {
 	__le32 sectorsize;
 	__le32 nodesize;
 	__le32 leafsize;
+	__le32 stripesize;
 	u8 root_level;
 } __attribute__ ((__packed__));
 
@@ -324,6 +325,9 @@ struct btrfs_root {
 	/* leaf allocations are done in leafsize units */
 	u32 leafsize;
 
+	/* leaf allocations are done in leafsize units */
+	u32 stripesize;
+
 	int ref_cows;
 	u32 type;
 };
@@ -903,6 +907,17 @@ static inline void btrfs_set_super_leafsize(struct btrfs_super_block *s,
 	s->leafsize = cpu_to_le32(val);
 }
 
+static inline u32 btrfs_super_stripesize(struct btrfs_super_block *s)
+{
+	return le32_to_cpu(s->stripesize);
+}
+
+static inline void btrfs_set_super_stripesize(struct btrfs_super_block *s,
+						u32 val)
+{
+	s->stripesize = cpu_to_le32(val);
+}
+
 static inline u64 btrfs_super_root_dir(struct btrfs_super_block *s)
 {
 	return le64_to_cpu(s->root_dir_objectid);
diff --git a/disk-io.c b/disk-io.c
index df77040..026cdfd 100644
--- a/disk-io.c
+++ b/disk-io.c
@@ -320,6 +320,7 @@ static int __setup_root(struct btrfs_super_block *super,
 	root->sectorsize = btrfs_super_sectorsize(super);
 	root->nodesize = btrfs_super_nodesize(super);
 	root->leafsize = btrfs_super_leafsize(super);
+	root->stripesize = btrfs_super_stripesize(super);
 	root->ref_cows = 0;
 	root->fs_info = fs_info;
 	memset(&root->root_key, 0, sizeof(root->root_key));
diff --git a/extent-tree.c b/extent-tree.c
index 8f7dc06..8615a43 100644
--- a/extent-tree.c
+++ b/extent-tree.c
@@ -372,6 +372,13 @@ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
 	return ret ? ret : pending_ret;
 }
 
+static u64 stripe_align(struct btrfs_root *root, u64 val)
+{
+	u64 mask = ((u64)root->stripesize - 1);
+	u64 ret = (val + mask) & ~mask;
+	return ret;
+}
+
 /*
  * walks the btree of allocated extents and find a hole of a given size.
  * The key ins is changed to record the hole:
@@ -390,6 +397,7 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
 	u64 hole_size = 0;
 	int slot = 0;
 	u64 last_byte = 0;
+	u64 aligned;
 	int start_found;
 	struct btrfs_leaf *l;
 	struct btrfs_root * root = orig_root->fs_info->extent_root;
@@ -397,6 +405,7 @@ static int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root
 	if (root->fs_info->last_insert.objectid > search_start)
 		search_start = root->fs_info->last_insert.objectid;
 
+	search_start = stripe_align(root, search_start);
 	btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY);
 
 check_failed:
@@ -421,13 +430,15 @@ check_failed:
 			if (ret < 0)
 				goto error;
 			if (!start_found) {
-				ins->objectid = search_start;
-				ins->offset = (u64)-1 - search_start;
+				aligned = stripe_align(root, search_start);
+				ins->objectid = aligned;
+				ins->offset = (u64)-1 - aligned;
 				start_found = 1;
 				goto check_pending;
 			}
-			ins->objectid = last_byte > search_start ?
-					last_byte : search_start;
+			ins->objectid = stripe_align(root,
+						     last_byte > search_start ?
+						     last_byte : search_start);
 			ins->offset = (u64)-1 - ins->objectid;
 			goto check_pending;
 		}
@@ -438,9 +449,11 @@ check_failed:
 			if (start_found) {
 				if (last_byte < search_start)
 					last_byte = search_start;
-				hole_size = key.objectid - last_byte;
-				if (hole_size > total_needed) {
-					ins->objectid = last_byte;
+				aligned = stripe_align(root, last_byte);
+				hole_size = key.objectid - aligned;
+				if (key.objectid > aligned &&
+				    hole_size > total_needed) {
+					ins->objectid = aligned;
 					ins->offset = hole_size;
 					goto check_pending;
 				}
diff --git a/mkfs.c b/mkfs.c
index 1f1519e..044117a 100644
--- a/mkfs.c
+++ b/mkfs.c
@@ -180,7 +180,7 @@ err:
 }
 
 int mkfs(int fd, char *pathname, u64 num_bytes, u32 nodesize, u32 leafsize,
-	 u32 sectorsize)
+	 u32 sectorsize, u32 stripesize)
 {
 	struct btrfs_super_block super;
 	struct btrfs_leaf *empty_leaf;
@@ -204,6 +204,7 @@ printf("blocksize is %d\n", leafsize);
 	btrfs_set_super_sectorsize(&super, sectorsize);
 	btrfs_set_super_leafsize(&super, leafsize);
 	btrfs_set_super_nodesize(&super, nodesize);
+	btrfs_set_super_stripesize(&super, stripesize);
 
 	num_bytes = (num_bytes / sectorsize) * sectorsize;
 	btrfs_set_super_total_bytes(&super, num_bytes);
@@ -353,12 +354,13 @@ int main(int ac, char **av)
 	u32 leafsize = 8 * 1024;
 	u32 sectorsize = 4096;
 	u32 nodesize = 8 * 1024;
+	u32 stripesize = 4096;
 	char *buf = malloc(sectorsize);
 	char *realpath_name;
 
 	while(1) {
 		int c;
-		c = getopt(ac, av, "l:n:");
+		c = getopt(ac, av, "l:n:s:");
 		if (c < 0)
 			break;
 		switch(c) {
@@ -368,6 +370,9 @@ int main(int ac, char **av)
 			case 'n':
 				nodesize = atol(optarg);
 				break;
+			case 's':
+				stripesize = atol(optarg);
+				break;
 			default:
 				print_usage();
 		}
@@ -426,7 +431,7 @@ int main(int ac, char **av)
 	}
 	realpath_name = realpath(file, NULL);
 	ret = mkfs(fd, realpath_name, block_count, nodesize, leafsize,
-		   sectorsize);
+		   sectorsize, stripesize);
 	if (ret) {
 		fprintf(stderr, "error during mkfs %d\n", ret);
 		exit(1);
-- 
2.7.4