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