btrfs-progs: extent-tree: Enhance btrfs_record_file_extent

Btrfs_record_file_extent() has some small problems like:
1) Can't handle overlapping extents
2) May create extent larger than BTRFS_MAX_EXTENT_SIZE

So enhance it using previously added facilites.
This is used for later btrfs-convert, as for new convert, we create
saved image first, then copy inode.
Which will also cause extent overlapping.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
Qu Wenruo 2016-01-29 13:03:24 +08:00 committed by David Sterba
parent f5e77e4c52
commit a21cc1ca3f
2 changed files with 142 additions and 78 deletions

View file

@ -578,6 +578,7 @@ struct btrfs_extent_item_v0 {
#define BTRFS_MAX_EXTENT_ITEM_SIZE(r) ((BTRFS_LEAF_DATA_SIZE(r) >> 4) - \
sizeof(struct btrfs_item))
#define BTRFS_MAX_EXTENT_SIZE (128 * 1024 * 1024)
#define BTRFS_EXTENT_FLAG_DATA (1ULL << 0)
#define BTRFS_EXTENT_FLAG_TREE_BLOCK (1ULL << 1)

View file

@ -3972,6 +3972,133 @@ next:
return 0;
}
static int __btrfs_record_file_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root, u64 objectid,
struct btrfs_inode_item *inode,
u64 file_pos, u64 disk_bytenr,
u64 *ret_num_bytes)
{
int ret;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_root *extent_root = info->extent_root;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_key ins_key;
struct btrfs_path *path;
struct btrfs_extent_item *ei;
u64 nbytes;
u64 extent_num_bytes;
u64 extent_bytenr;
u64 extent_offset;
u64 num_bytes = *ret_num_bytes;
num_bytes = min_t(u64, num_bytes, BTRFS_MAX_EXTENT_SIZE);
/*
* All supported file system should not use its 0 extent.
* As it's for hole
*/
if (disk_bytenr == 0) {
ret = btrfs_insert_file_extent(trans, root, objectid,
file_pos, disk_bytenr,
num_bytes, num_bytes);
return ret;
}
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
/* First to check extent overlap */
ret = btrfs_search_overlap_extent(extent_root, path, disk_bytenr,
num_bytes);
if (ret < 0)
goto fail;
if (ret > 0) {
/* Found overlap */
u64 cur_start;
u64 cur_len;
__get_extent_size(extent_root, path, &cur_start, &cur_len);
/*
* For convert case, this extent should be a subset of
* existing one.
*/
BUG_ON(disk_bytenr < cur_start);
extent_bytenr = cur_start;
extent_num_bytes = cur_len;
extent_offset = disk_bytenr - extent_bytenr;
} else {
/* No overlap, create new extent */
btrfs_release_path(path);
ins_key.objectid = disk_bytenr;
ins_key.offset = num_bytes;
ins_key.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_insert_empty_item(trans, extent_root, path,
&ins_key, sizeof(*ei));
if (ret == 0) {
leaf = path->nodes[0];
ei = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, ei, 0);
btrfs_set_extent_generation(leaf, ei, 0);
btrfs_set_extent_flags(leaf, ei,
BTRFS_EXTENT_FLAG_DATA);
btrfs_mark_buffer_dirty(leaf);
ret = btrfs_update_block_group(trans, root, disk_bytenr,
num_bytes, 1, 0);
if (ret)
goto fail;
} else if (ret != -EEXIST) {
goto fail;
}
btrfs_extent_post_op(trans, extent_root);
extent_bytenr = disk_bytenr;
extent_num_bytes = num_bytes;
extent_offset = 0;
}
btrfs_release_path(path);
ins_key.objectid = objectid;
ins_key.offset = file_pos;
btrfs_set_key_type(&ins_key, BTRFS_EXTENT_DATA_KEY);
ret = btrfs_insert_empty_item(trans, root, path, &ins_key,
sizeof(*fi));
if (ret)
goto fail;
leaf = path->nodes[0];
fi = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, fi, trans->transid);
btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG);
btrfs_set_file_extent_disk_bytenr(leaf, fi, extent_bytenr);
btrfs_set_file_extent_disk_num_bytes(leaf, fi, extent_num_bytes);
btrfs_set_file_extent_offset(leaf, fi, extent_offset);
btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
btrfs_set_file_extent_ram_bytes(leaf, fi, extent_num_bytes);
btrfs_set_file_extent_compression(leaf, fi, 0);
btrfs_set_file_extent_encryption(leaf, fi, 0);
btrfs_set_file_extent_other_encoding(leaf, fi, 0);
btrfs_mark_buffer_dirty(leaf);
nbytes = btrfs_stack_inode_nbytes(inode) + num_bytes;
btrfs_set_stack_inode_nbytes(inode, nbytes);
btrfs_release_path(path);
ret = btrfs_inc_extent_ref(trans, root, extent_bytenr, extent_num_bytes,
0, root->root_key.objectid, objectid,
file_pos - extent_offset);
if (ret)
goto fail;
ret = 0;
*ret_num_bytes = min(extent_num_bytes - extent_offset, num_bytes);
fail:
btrfs_free_path(path);
return ret;
}
/*
* Record a file extent. Do all the required works, such as inserting
* file extent item, inserting extent item and backref item into extent
@ -3983,86 +4110,22 @@ int btrfs_record_file_extent(struct btrfs_trans_handle *trans,
u64 file_pos, u64 disk_bytenr,
u64 num_bytes)
{
int ret;
struct btrfs_fs_info *info = root->fs_info;
struct btrfs_root *extent_root = info->extent_root;
struct extent_buffer *leaf;
struct btrfs_file_extent_item *fi;
struct btrfs_key ins_key;
struct btrfs_path path;
struct btrfs_extent_item *ei;
u64 nbytes;
u64 cur_disk_bytenr = disk_bytenr;
u64 cur_file_pos = file_pos;
u64 cur_num_bytes = num_bytes;
int ret = 0;
if (disk_bytenr == 0) {
ret = btrfs_insert_file_extent(trans, root, objectid,
file_pos, disk_bytenr,
num_bytes, num_bytes);
return ret;
while (num_bytes > 0) {
ret = __btrfs_record_file_extent(trans, root, objectid,
inode, cur_file_pos,
cur_disk_bytenr,
&cur_num_bytes);
if (ret < 0)
break;
cur_disk_bytenr += cur_num_bytes;
cur_file_pos += cur_num_bytes;
num_bytes -= cur_num_bytes;
}
btrfs_init_path(&path);
ins_key.objectid = objectid;
ins_key.offset = file_pos;
btrfs_set_key_type(&ins_key, BTRFS_EXTENT_DATA_KEY);
ret = btrfs_insert_empty_item(trans, root, &path, &ins_key,
sizeof(*fi));
if (ret)
goto fail;
leaf = path.nodes[0];
fi = btrfs_item_ptr(leaf, path.slots[0],
struct btrfs_file_extent_item);
btrfs_set_file_extent_generation(leaf, fi, trans->transid);
btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG);
btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
btrfs_set_file_extent_disk_num_bytes(leaf, fi, num_bytes);
btrfs_set_file_extent_offset(leaf, fi, 0);
btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
btrfs_set_file_extent_compression(leaf, fi, 0);
btrfs_set_file_extent_encryption(leaf, fi, 0);
btrfs_set_file_extent_other_encoding(leaf, fi, 0);
btrfs_mark_buffer_dirty(leaf);
nbytes = btrfs_stack_inode_nbytes(inode) + num_bytes;
btrfs_set_stack_inode_nbytes(inode, nbytes);
btrfs_release_path(&path);
ins_key.objectid = disk_bytenr;
ins_key.offset = num_bytes;
ins_key.type = BTRFS_EXTENT_ITEM_KEY;
ret = btrfs_insert_empty_item(trans, extent_root, &path,
&ins_key, sizeof(*ei));
if (ret == 0) {
leaf = path.nodes[0];
ei = btrfs_item_ptr(leaf, path.slots[0],
struct btrfs_extent_item);
btrfs_set_extent_refs(leaf, ei, 0);
btrfs_set_extent_generation(leaf, ei, 0);
btrfs_set_extent_flags(leaf, ei, BTRFS_EXTENT_FLAG_DATA);
btrfs_mark_buffer_dirty(leaf);
ret = btrfs_update_block_group(trans, root, disk_bytenr,
num_bytes, 1, 0);
if (ret)
goto fail;
} else if (ret != -EEXIST) {
goto fail;
}
btrfs_extent_post_op(trans, extent_root);
ret = btrfs_inc_extent_ref(trans, root, disk_bytenr, num_bytes, 0,
root->root_key.objectid,
objectid, file_pos);
if (ret)
goto fail;
ret = 0;
fail:
btrfs_release_path(&path);
return ret;
}