@@ -709,6 +709,10 @@ static struct extent_map *defrag_get_extent(struct btrfs_inode *inode,
em->start = start;
em->orig_start = start;
em->block_start = EXTENT_MAP_HOLE;
+ em->disk_bytenr = EXTENT_MAP_HOLE;
+ em->disk_num_bytes = 0;
+ em->ram_bytes = 0;
+ em->offset = 0;
em->len = key.offset - start;
break;
}
@@ -232,6 +232,58 @@ static bool mergeable_maps(const struct extent_map *prev, const struct extent_ma
return next->block_start == prev->block_start;
}
+/*
+ * Handle the ondisk data extents merge for @prev and @next.
+ *
+ * Only touches disk_bytenr/disk_num_bytes/offset/ram_bytes.
+ * For now only uncompressed regular extent can be merged.
+ *
+ * @prev and @next will be both updated to point to the new merged range.
+ * Thus one of them should be removed by the caller.
+ */
+static void merge_ondisk_extents(struct extent_map *prev, struct extent_map *next)
+{
+ u64 new_disk_bytenr;
+ u64 new_disk_num_bytes;
+ u64 new_offset;
+
+ /* @prev and @next should not be compressed. */
+ ASSERT(!extent_map_is_compressed(prev));
+ ASSERT(!extent_map_is_compressed(next));
+
+ /*
+ * There are several different cases that @prev and @next can be merged.
+ *
+ * 1) They are referring to the same data extent
+ * 2) Their ondisk data extents are adjacent and @prev is the tail
+ * and @next is the head of their data extents
+ * 3) One of @prev/@next is referrring to a larger merged data extent.
+ * (test_case_3 of extent maps tests).
+ *
+ * The calculation here always merge the data extents first, then update
+ * @offset using the new data extents.
+ *
+ * For case 1), the merged data extent would be the same.
+ * For case 2), we just merge the two data extents into one.
+ * For case 3), we just got the larger data extent.
+ */
+ new_disk_bytenr = min(prev->disk_bytenr, next->disk_bytenr);
+ new_disk_num_bytes = max(prev->disk_bytenr + prev->disk_num_bytes,
+ next->disk_bytenr + next->disk_num_bytes) -
+ new_disk_bytenr;
+ new_offset = prev->disk_bytenr + prev->offset - new_disk_bytenr;
+
+ prev->disk_bytenr = new_disk_bytenr;
+ prev->disk_num_bytes = new_disk_num_bytes;
+ prev->ram_bytes = new_disk_num_bytes;
+ prev->offset = new_offset;
+
+ next->disk_bytenr = new_disk_bytenr;
+ next->disk_num_bytes = new_disk_num_bytes;
+ next->ram_bytes = new_disk_num_bytes;
+ next->offset = new_offset;
+}
+
static void try_merge_map(struct btrfs_inode *inode, struct extent_map *em)
{
struct extent_map_tree *tree = &inode->extent_tree;
@@ -263,6 +315,9 @@ static void try_merge_map(struct btrfs_inode *inode, struct extent_map *em)
em->block_len += merge->block_len;
em->block_start = merge->block_start;
em->generation = max(em->generation, merge->generation);
+
+ if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE)
+ merge_ondisk_extents(merge, em);
em->flags |= EXTENT_FLAG_MERGED;
rb_erase_cached(&merge->rb_node, &tree->map);
@@ -278,6 +333,8 @@ static void try_merge_map(struct btrfs_inode *inode, struct extent_map *em)
if (rb && can_merge_extent_map(merge) && mergeable_maps(em, merge)) {
em->len += merge->len;
em->block_len += merge->block_len;
+ if (em->disk_bytenr < EXTENT_MAP_LAST_BYTE)
+ merge_ondisk_extents(em, merge);
rb_erase_cached(&merge->rb_node, &tree->map);
RB_CLEAR_NODE(&merge->rb_node);
em->generation = max(em->generation, merge->generation);
@@ -565,6 +622,7 @@ static noinline int merge_extent_mapping(struct btrfs_inode *inode,
!extent_map_is_compressed(em)) {
em->block_start += start_diff;
em->block_len = em->len;
+ em->offset += start_diff;
}
return add_extent_mapping(inode, em, 0);
}
@@ -783,14 +841,18 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end,
split->block_len = em->block_len;
else
split->block_len = split->len;
+ split->disk_bytenr = em->disk_bytenr;
split->disk_num_bytes = max(split->block_len,
em->disk_num_bytes);
+ split->offset = em->offset;
split->ram_bytes = em->ram_bytes;
} else {
split->orig_start = split->start;
split->block_len = 0;
split->block_start = em->block_start;
+ split->disk_bytenr = em->disk_bytenr;
split->disk_num_bytes = 0;
+ split->offset = 0;
split->ram_bytes = split->len;
}
@@ -811,13 +873,14 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end,
split->start = end;
split->len = em_end - end;
split->block_start = em->block_start;
+ split->disk_bytenr = em->disk_bytenr;
split->flags = flags;
split->generation = gen;
if (em->block_start < EXTENT_MAP_LAST_BYTE) {
split->disk_num_bytes = max(em->block_len,
em->disk_num_bytes);
-
+ split->offset = em->offset + end - em->start;
split->ram_bytes = em->ram_bytes;
if (compressed) {
split->block_len = em->block_len;
@@ -830,10 +893,11 @@ void btrfs_drop_extent_map_range(struct btrfs_inode *inode, u64 start, u64 end,
split->orig_start = em->orig_start;
}
} else {
+ split->disk_num_bytes = 0;
+ split->offset = 0;
split->ram_bytes = split->len;
split->orig_start = split->start;
split->block_len = 0;
- split->disk_num_bytes = 0;
}
if (extent_map_in_tree(em)) {
@@ -987,6 +1051,9 @@ int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre,
/* First, replace the em with a new extent_map starting from * em->start */
split_pre->start = em->start;
split_pre->len = pre;
+ split_pre->disk_bytenr = new_logical;
+ split_pre->disk_num_bytes = split_pre->len;
+ split_pre->offset = 0;
split_pre->orig_start = split_pre->start;
split_pre->block_start = new_logical;
split_pre->block_len = split_pre->len;
@@ -1005,10 +1072,12 @@ int split_extent_map(struct btrfs_inode *inode, u64 start, u64 len, u64 pre,
/* Insert the middle extent_map. */
split_mid->start = em->start + pre;
split_mid->len = em->len - pre;
+ split_mid->disk_bytenr = em->block_start + pre;
+ split_mid->disk_num_bytes = split_mid->len;
+ split_mid->offset = 0;
split_mid->orig_start = split_mid->start;
split_mid->block_start = em->block_start + pre;
split_mid->block_len = split_mid->len;
- split_mid->disk_num_bytes = split_mid->block_len;
split_mid->ram_bytes = split_mid->len;
split_mid->flags = flags;
split_mid->generation = em->generation;
@@ -71,12 +71,29 @@ struct extent_map {
*/
u64 orig_start;
+ /*
+ * The bytenr for of the full on-disk extent.
+ *
+ * For regular extents it's btrfs_file_extent_item::disk_bytenr.
+ * For holes it's EXTENT_MAP_HOLE and for inline extents it's
+ * EXTENT_MAP_INLINE.
+ */
+ u64 disk_bytenr;
+
/*
* The full on-disk extent length, matching
* btrfs_file_extent_item::disk_num_bytes.
*/
u64 disk_num_bytes;
+ /*
+ * Offset inside the decompressed extent.
+ *
+ * For regular extents it's btrfs_file_extent_item::offset.
+ * For holes and inline extents it's 0.
+ */
+ u64 offset;
+
/*
* The decompressed size of the whole on-disk extent, matching
* btrfs_file_extent_item::ram_bytes.
@@ -1294,12 +1294,17 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
em->len = btrfs_file_extent_end(path) - extent_start;
em->orig_start = extent_start -
btrfs_file_extent_offset(leaf, fi);
- em->disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
if (bytenr == 0) {
em->block_start = EXTENT_MAP_HOLE;
+ em->disk_bytenr = EXTENT_MAP_HOLE;
+ em->disk_num_bytes = 0;
+ em->offset = 0;
return;
}
+ em->disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
+ em->disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
+ em->offset = btrfs_file_extent_offset(leaf, fi);
if (compress_type != BTRFS_COMPRESS_NONE) {
extent_map_set_compression(em, compress_type);
em->block_start = bytenr;
@@ -1316,8 +1321,10 @@ void btrfs_extent_item_to_extent_map(struct btrfs_inode *inode,
ASSERT(extent_start == 0);
em->block_start = EXTENT_MAP_INLINE;
+ em->disk_bytenr = EXTENT_MAP_INLINE;
em->start = 0;
em->len = fs_info->sectorsize;
+ em->offset = 0;
/*
* Initialize orig_start and block_len with the same values
* as in inode.c:btrfs_get_extent().
@@ -2337,6 +2337,7 @@ static int fill_holes(struct btrfs_trans_handle *trans,
hole_em->orig_start = offset;
hole_em->block_start = EXTENT_MAP_HOLE;
+ hole_em->disk_bytenr = EXTENT_MAP_HOLE;
hole_em->block_len = 0;
hole_em->disk_num_bytes = 0;
hole_em->generation = trans->transid;
@@ -139,8 +139,9 @@ static noinline int run_delalloc_cow(struct btrfs_inode *inode,
bool pages_dirty);
static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
u64 len, u64 orig_start, u64 block_start,
- u64 block_len, u64 orig_block_len,
+ u64 block_len, u64 disk_num_bytes,
u64 ram_bytes, int compress_type,
+ struct btrfs_file_extent *file_extent,
int type);
static int data_reloc_print_warning_inode(u64 inum, u64 offset, u64 num_bytes,
@@ -1114,6 +1115,7 @@ static void submit_one_async_extent(struct async_chunk *async_chunk,
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_ordered_extent *ordered;
+ struct btrfs_file_extent file_extent = { 0 };
struct btrfs_key ins;
struct page *locked_page = NULL;
struct extent_map *em;
@@ -1158,6 +1160,13 @@ static void submit_one_async_extent(struct async_chunk *async_chunk,
}
/* Here we're doing allocation and writeback of the compressed pages */
+ file_extent.disk_bytenr = ins.objectid;
+ file_extent.disk_num_bytes = ins.offset;
+ file_extent.ram_bytes = async_extent->ram_size;
+ file_extent.num_bytes = async_extent->ram_size;
+ file_extent.offset = 0;
+ file_extent.compression = async_extent->compress_type;
+
em = create_io_em(inode, start,
async_extent->ram_size, /* len */
start, /* orig_start */
@@ -1166,6 +1175,7 @@ static void submit_one_async_extent(struct async_chunk *async_chunk,
ins.offset, /* orig_block_len */
async_extent->ram_size, /* ram_bytes */
async_extent->compress_type,
+ &file_extent,
BTRFS_ORDERED_COMPRESSED);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
@@ -1385,6 +1395,7 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
while (num_bytes > 0) {
struct btrfs_ordered_extent *ordered;
+ struct btrfs_file_extent file_extent = { 0 };
cur_alloc_size = num_bytes;
ret = btrfs_reserve_extent(root, cur_alloc_size, cur_alloc_size,
@@ -1421,6 +1432,12 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
extent_reserved = true;
ram_size = ins.offset;
+ file_extent.disk_bytenr = ins.objectid;
+ file_extent.disk_num_bytes = ins.offset;
+ file_extent.num_bytes = ins.offset;
+ file_extent.ram_bytes = ins.offset;
+ file_extent.offset = 0;
+ file_extent.compression = BTRFS_COMPRESS_NONE;
em = create_io_em(inode, start, ins.offset, /* len */
start, /* orig_start */
ins.objectid, /* block_start */
@@ -1428,6 +1445,7 @@ static noinline int cow_file_range(struct btrfs_inode *inode,
ins.offset, /* orig_block_len */
ram_size, /* ram_bytes */
BTRFS_COMPRESS_NONE, /* compress_type */
+ &file_extent,
BTRFS_ORDERED_REGULAR /* type */);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
@@ -1828,6 +1846,7 @@ struct can_nocow_file_extent_args {
u64 disk_bytenr;
u64 disk_num_bytes;
u64 extent_offset;
+
/* Number of bytes that can be written to in NOCOW mode. */
u64 num_bytes;
@@ -2152,6 +2171,7 @@ static noinline int run_delalloc_nocow(struct btrfs_inode *inode,
nocow_args.num_bytes, /* block_len */
nocow_args.disk_num_bytes, /* orig_block_len */
ram_bytes, BTRFS_COMPRESS_NONE,
+ &nocow_args.file_extent,
BTRFS_ORDERED_PREALLOC);
if (IS_ERR(em)) {
btrfs_dec_nocow_writers(nocow_bg);
@@ -4941,6 +4961,7 @@ int btrfs_cont_expand(struct btrfs_inode *inode, loff_t oldsize, loff_t size)
hole_em->orig_start = cur_offset;
hole_em->block_start = EXTENT_MAP_HOLE;
+ hole_em->disk_bytenr = EXTENT_MAP_HOLE;
hole_em->block_len = 0;
hole_em->disk_num_bytes = 0;
hole_em->ram_bytes = hole_size;
@@ -6801,6 +6822,7 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode,
}
em->start = EXTENT_MAP_HOLE;
em->orig_start = EXTENT_MAP_HOLE;
+ em->disk_bytenr = EXTENT_MAP_HOLE;
em->len = (u64)-1;
em->block_len = (u64)-1;
@@ -6966,7 +6988,8 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
const u64 block_len,
const u64 orig_block_len,
const u64 ram_bytes,
- const int type)
+ const int type,
+ struct btrfs_file_extent *file_extent)
{
struct extent_map *em = NULL;
struct btrfs_ordered_extent *ordered;
@@ -6975,7 +6998,7 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,
em = create_io_em(inode, start, len, orig_start, block_start,
block_len, orig_block_len, ram_bytes,
BTRFS_COMPRESS_NONE, /* compress_type */
- type);
+ file_extent, type);
if (IS_ERR(em))
goto out;
}
@@ -7006,6 +7029,7 @@ static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode,
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
+ struct btrfs_file_extent file_extent = { 0 };
struct extent_map *em;
struct btrfs_key ins;
u64 alloc_hint;
@@ -7024,9 +7048,16 @@ static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode,
if (ret)
return ERR_PTR(ret);
+ file_extent.disk_bytenr = ins.objectid;
+ file_extent.disk_num_bytes = ins.offset;
+ file_extent.num_bytes = ins.offset;
+ file_extent.ram_bytes = ins.offset;
+ file_extent.offset = 0;
+ file_extent.compression = BTRFS_COMPRESS_NONE;
em = btrfs_create_dio_extent(inode, dio_data, start, ins.offset, start,
ins.objectid, ins.offset, ins.offset,
- ins.offset, BTRFS_ORDERED_REGULAR);
+ ins.offset, BTRFS_ORDERED_REGULAR,
+ &file_extent);
btrfs_dec_block_group_reservations(fs_info, ins.objectid);
if (IS_ERR(em))
btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset,
@@ -7269,6 +7300,7 @@ static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
u64 len, u64 orig_start, u64 block_start,
u64 block_len, u64 disk_num_bytes,
u64 ram_bytes, int compress_type,
+ struct btrfs_file_extent *file_extent,
int type)
{
struct extent_map *em;
@@ -7326,9 +7358,11 @@ static struct extent_map *create_io_em(struct btrfs_inode *inode, u64 start,
em->len = len;
em->block_len = block_len;
em->block_start = block_start;
+ em->disk_bytenr = file_extent->disk_bytenr;
em->disk_num_bytes = disk_num_bytes;
em->ram_bytes = ram_bytes;
em->generation = -1;
+ em->offset = file_extent->offset;
em->flags |= EXTENT_FLAG_PINNED;
if (type == BTRFS_ORDERED_COMPRESSED)
extent_map_set_compression(em, compress_type);
@@ -7352,6 +7386,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
{
const bool nowait = (iomap_flags & IOMAP_NOWAIT);
struct btrfs_fs_info *fs_info = inode_to_fs_info(inode);
+ struct btrfs_file_extent file_extent = { 0 };
struct extent_map *em = *map;
int type;
u64 block_start, orig_start, orig_block_len, ram_bytes;
@@ -7382,7 +7417,8 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
block_start = em->block_start + (start - em->start);
if (can_nocow_extent(inode, start, &len, &orig_start,
- &orig_block_len, &ram_bytes, NULL, false, false) == 1) {
+ &orig_block_len, &ram_bytes,
+ &file_extent, false, false) == 1) {
bg = btrfs_inc_nocow_writers(fs_info, block_start);
if (bg)
can_nocow = true;
@@ -7410,7 +7446,8 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map,
em2 = btrfs_create_dio_extent(BTRFS_I(inode), dio_data, start, len,
orig_start, block_start,
len, orig_block_len,
- ram_bytes, type);
+ ram_bytes, type,
+ &file_extent);
btrfs_dec_nocow_writers(bg);
if (type == BTRFS_ORDERED_PREALLOC) {
free_extent_map(em);
@@ -9561,6 +9598,8 @@ static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
em->orig_start = cur_offset;
em->len = ins.offset;
em->block_start = ins.objectid;
+ em->disk_bytenr = ins.objectid;
+ em->offset = 0;
em->block_len = ins.offset;
em->disk_num_bytes = ins.offset;
em->ram_bytes = ins.offset;
@@ -10127,6 +10166,7 @@ ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
struct extent_changeset *data_reserved = NULL;
struct extent_state *cached_state = NULL;
struct btrfs_ordered_extent *ordered;
+ struct btrfs_file_extent file_extent = { 0 };
int compression;
size_t orig_count;
u64 start, end;
@@ -10300,10 +10340,16 @@ ssize_t btrfs_do_encoded_write(struct kiocb *iocb, struct iov_iter *from,
goto out_delalloc_release;
extent_reserved = true;
+ file_extent.disk_bytenr = ins.objectid;
+ file_extent.disk_num_bytes = ins.offset;
+ file_extent.num_bytes = num_bytes;
+ file_extent.ram_bytes = ram_bytes;
+ file_extent.offset = encoded->unencoded_offset;
+ file_extent.compression = compression;
em = create_io_em(inode, start, num_bytes,
start - encoded->unencoded_offset, ins.objectid,
ins.offset, ins.offset, ram_bytes, compression,
- BTRFS_ORDERED_COMPRESSED);
+ &file_extent, BTRFS_ORDERED_COMPRESSED);
if (IS_ERR(em)) {
ret = PTR_ERR(em);
goto out_free_reserved;
Introduce two new members for extent_map: - disk_bytenr - offset Both are matching the members with the same name inside btrfs_file_extent_items. For now this patch only touches those members when: - Reading btrfs_file_extent_items from disk - Inserting new holes - Merging two extent maps With the new disk_bytenr and disk_num_bytes, doing merging would be a little complex, as we have 3 different cases: * Both extent maps are referring to the same data extent * Both extent maps are referring to different data extents, but those data extents are adjacent, and extent maps are at head/tail of each data extents * One of the extent map is referring to an merged and larger data extent that covers both extent maps The 3rd case seems only valid in selftest (test_case_3()), but a new helper merge_ondisk_extents() should be able to handle all of them. To properly assign values for those new members, a new btrfs_file_extent parameter is introduced to all the involved call sites. - For NOCOW writes the btrfs_file_extent would be exposed from can_nocow_file_extent(). - For other writes, the members can be easily calculated As most of them have 0 offset and utilizing the whole on-disk data extent. The exception is encoded write, but thankfully that interface provided offset directly and all other needed info. For now, both the old members (block_start/block_len/orig_start) are co-existing with the new members (disk_bytenr/offset), meanwhile all the critical code is still using the old members only. The cleanup would happen later after all the older and newer members are properly validated. Signed-off-by: Qu Wenruo <wqu@suse.com> --- fs/btrfs/defrag.c | 4 +++ fs/btrfs/extent_map.c | 75 +++++++++++++++++++++++++++++++++++++++++-- fs/btrfs/extent_map.h | 17 ++++++++++ fs/btrfs/file-item.c | 9 +++++- fs/btrfs/file.c | 1 + fs/btrfs/inode.c | 60 ++++++++++++++++++++++++++++++---- 6 files changed, 155 insertions(+), 11 deletions(-)