Since we have reserved ranges array now, we can use them to skip all
these open codes.
And add some comment and asciidoc art for related part.
Signed-off-by: Qu Wenruo <quwen...@cn.fujitsu.com>
---
convert/main.c | 138 ++++++++++++++++++++++++++-------------------------------
1 file changed, 63 insertions(+), 75 deletions(-)
diff --git a/convert/main.c b/convert/main.c
index 41309645..e834c6f9 100644
--- a/convert/main.c
+++ b/convert/main.c
@@ -205,47 +205,40 @@ static int create_image_file_range(struct
btrfs_trans_handle *trans,
len = min_t(u64, len, BTRFS_MAX_EXTENT_SIZE);
/*
- * Skip sb ranges first
- * [0, 1M), [sb_offset(1), +64K), [sb_offset(2), +64K].
+ * Skip reserved ranges first
*
* Or we will insert a hole into current image file, and later
* migrate block will fail as there is already a file extent.
*/
- if (bytenr < 1024 * 1024) {
- *ret_len = 1024 * 1024 - bytenr;
- return 0;
- }
- for (i = 1; i < BTRFS_SUPER_MIRROR_MAX; i++) {
- u64 cur = btrfs_sb_offset(i);
+ for (i = 0; i < ARRAY_SIZE(btrfs_reserved_ranges); i++) {
+ const struct simple_range *reserved = &btrfs_reserved_ranges[i];
- if (bytenr >= cur && bytenr < cur + BTRFS_STRIPE_LEN) {
- *ret_len = cur + BTRFS_STRIPE_LEN - bytenr;
+ /*
+ * |-- reserved --|
+ * |--range---|
+ * or
+ * |---- reserved ----|
+ * |-- range --|
+ * Skip to reserved range end
+ */
+ if (bytenr >= reserved->start && bytenr < range_end(reserved)) {
+ *ret_len = range_end(reserved) - bytenr;
return 0;
}
- }
- for (i = 1; i < BTRFS_SUPER_MIRROR_MAX; i++) {
- u64 cur = btrfs_sb_offset(i);
/*
- * |--reserved--|
+ * |---reserved---|
* |----range-------|
- * May still need to go through file extent inserts
+ * Leading part may still create a file extent
*/
- if (bytenr < cur && bytenr + len >= cur) {
- len = min_t(u64, len, cur - bytenr);
+ if (bytenr < reserved->start &&
+ bytenr + len >= range_end(reserved)) {
+ len = min_t(u64, len, reserved->start - bytenr);
break;
}
- /*
- * |--reserved--|
- * |---range---|
- * Drop out, no need to insert anything
- */
- if (bytenr >= cur && bytenr < cur + BTRFS_STRIPE_LEN) {
- *ret_len = cur + BTRFS_STRIPE_LEN - bytenr;
- return 0;
- }
}
+ /* Check if we are going to insert regular file extent or hole */
cache = search_cache_extent(used, bytenr);
if (cache) {
if (cache->start <= bytenr) {
@@ -253,6 +246,7 @@ static int create_image_file_range(struct
btrfs_trans_handle *trans,
* |///////Used///////|
* |<--insert--->|
* bytenr
+ * Regular file extent
*/
len = min_t(u64, len, cache->start + cache->size -
bytenr);
@@ -262,6 +256,7 @@ static int create_image_file_range(struct
btrfs_trans_handle *trans,
* |//Used//|
* |<-insert-->|
* bytenr
+ * Hole
*/
len = min(len, cache->start - bytenr);
disk_bytenr = 0;
@@ -272,6 +267,7 @@ static int create_image_file_range(struct
btrfs_trans_handle *trans,
* |//Used//| |EOF
* |<-insert-->|
* bytenr
+ * Hole
*/
disk_bytenr = 0;
datacsum = 0;
@@ -317,24 +313,31 @@ static int migrate_one_reserved_range(struct
btrfs_trans_handle *trans,
struct btrfs_root *root,
struct cache_tree *used,
struct btrfs_inode_item *inode, int fd,
- u64 ino, u64 start, u64 len,
+ u64 ino, const struct simple_range *range,
u32 convert_flags)
{
- u64 cur_off = start;
- u64 cur_len = len;
- u64 hole_start = start;
+ u64 cur_off = range->start;
+ u64 cur_len = range->len;
+ u64 hole_start = range->start;
u64 hole_len;
struct cache_extent *cache;
struct btrfs_key key;
struct extent_buffer *eb;
int ret = 0;
- while (cur_off < start + len) {
+ /*
+ * It's possible that there are holes in reserved range:
+ * |<---------------- Reserved range ---------------------->|
+ * |<- Old fs data ->| |<- Old fs data ->|
+ * So here we need to iterate through old fs used space and only
+ * migrate ranges that covered by old fs data.
+ */
+ while (cur_off < range_end(range)) {
cache = lookup_cache_extent(used, cur_off, cur_len);
if (!cache)
break;
cur_off = max(cache->start, cur_off);
- cur_len = min(cache->start + cache->size, start + len) -
+ cur_len = min(cache->start + cache->size, range_end(range)) -
cur_off;
BUG_ON(cur_len < root->sectorsize);
@@ -386,20 +389,22 @@ static int migrate_one_reserved_range(struct
btrfs_trans_handle *trans,
cur_off += key.offset;
hole_start = cur_off;
- cur_len = start + len - cur_off;
+ cur_len = range_end(range) - cur_off;
}
- /* Last hole */
- if (start + len - hole_start > 0)
+ /*
+ * Last hole
+ * |<---- reserved -------->|
+ * |<- Old fs data ->| |
+ * | Hole |
+ */
+ if (range_end(range) - hole_start > 0)
ret = btrfs_record_file_extent(trans, root, ino, inode,
- hole_start, 0, start + len - hole_start);
+ hole_start, 0, range_end(range) - hole_start);
return ret;
}
/*
* Relocate the used ext2 data in reserved ranges
- * [0,1M)
- * [btrfs_sb_offset(1), +BTRFS_STRIPE_LEN)
- * [btrfs_sb_offset(2), +BTRFS_STRIPE_LEN)
*/
static int migrate_reserved_ranges(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
@@ -407,35 +412,19 @@ static int migrate_reserved_ranges(struct
btrfs_trans_handle *trans,
struct btrfs_inode_item *inode, int fd,
u64 ino, u64 total_bytes, u32 convert_flags)
{
- u64 cur_off;
- u64 cur_len;
+ int i;
int ret = 0;
- /* 0 ~ 1M */
- cur_off = 0;
- cur_len = 1024 * 1024;
- ret = migrate_one_reserved_range(trans, root, used, inode, fd, ino,
- cur_off, cur_len, convert_flags);
- if (ret < 0)
- return ret;
+ for (i = 0; i < ARRAY_SIZE(btrfs_reserved_ranges); i++) {
+ const struct simple_range *range = &btrfs_reserved_ranges[i];
- /* second sb(fisrt sb is included in 0~1M) */
- cur_off = btrfs_sb_offset(1);
- cur_len = min(total_bytes, cur_off + BTRFS_STRIPE_LEN) - cur_off;
- if (cur_off > total_bytes)
- return ret;
- ret = migrate_one_reserved_range(trans, root, used, inode, fd, ino,
- cur_off, cur_len, convert_flags);
- if (ret < 0)
- return ret;
-
- /* Last sb */
- cur_off = btrfs_sb_offset(2);
- cur_len = min(total_bytes, cur_off + BTRFS_STRIPE_LEN) - cur_off;
- if (cur_off > total_bytes)
- return ret;
- ret = migrate_one_reserved_range(trans, root, used, inode, fd, ino,
- cur_off, cur_len, convert_flags);
+ if (range->start > total_bytes)
+ return ret;
+ ret = migrate_one_reserved_range(trans, root, used, inode, fd,
+ ino, range, convert_flags);
+ if (ret < 0)
+ return ret;
+ }
return ret;
}
@@ -608,18 +597,17 @@ static int wipe_one_reserved_range(struct cache_tree
*tree,
static int wipe_reserved_ranges(struct cache_tree *tree, u64 min_stripe_size,
int ensure_size)
{
+ int i;
int ret;
- ret = wipe_one_reserved_range(tree, 0, 1024 * 1024, min_stripe_size,
- ensure_size);
- if (ret < 0)
- return ret;
- ret = wipe_one_reserved_range(tree, btrfs_sb_offset(1),
- BTRFS_STRIPE_LEN, min_stripe_size, ensure_size);
- if (ret < 0)
- return ret;
- ret = wipe_one_reserved_range(tree, btrfs_sb_offset(2),
- BTRFS_STRIPE_LEN, min_stripe_size, ensure_size);
+ for (i = 0; i < ARRAY_SIZE(btrfs_reserved_ranges); i++) {
+ const struct simple_range *range = &btrfs_reserved_ranges[i];
+
+ ret = wipe_one_reserved_range(tree, range->start, range->len,
+ min_stripe_size, ensure_size);
+ if (ret < 0)
+ return ret;
+ }
return ret;
}
--
2.12.0
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
