Btrfs: progress on file_write
Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason
committed by
David Woodhouse
David Woodhouse
parent
6567e837df
commit
b18c668581
284
fs/btrfs/super.c
284
fs/btrfs/super.c
@@ -1089,7 +1089,6 @@ static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
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extent_start = btrfs_disk_key_offset(&leaf->items[path->slots[0]].key);
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extent_start = extent_start >> inode->i_blkbits;
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extent_start += btrfs_file_extent_offset(item);
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extent_end = extent_start + btrfs_file_extent_num_blocks(item);
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if (iblock >= extent_start && iblock < extent_end) {
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err = 0;
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@@ -1103,6 +1102,7 @@ allocate:
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err = 0;
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goto out;
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}
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#if 0
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ret = btrfs_alloc_file_extent(trans, root, objectid,
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iblock << inode->i_blkbits,
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1, extent_end, &blocknr);
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@@ -1115,9 +1115,11 @@ allocate:
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map_bh(result, inode->i_sb, blocknr);
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btrfs_map_bh_to_logical(root, result, blocknr);
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#endif
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out:
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btrfs_release_path(root, path);
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btrfs_free_path(path);
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printk("mapping iblock %lu to %lu\n", iblock, result->b_blocknr);
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if (trans)
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btrfs_end_transaction(trans, root);
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return err;
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@@ -1273,8 +1275,244 @@ failed:
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return err;
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}
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static int prepare_pages(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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static int drop_csums(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct inode *inode,
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u64 start, u64 end)
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{
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struct btrfs_path *path;
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struct btrfs_leaf *leaf;
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struct btrfs_key key;
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int slot;
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struct btrfs_csum_item *item;
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char *old_block = NULL;
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u64 cur = start;
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u64 found_end;
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u64 num_csums;
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u64 item_size;
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int ret;
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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while(cur < end) {
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item = btrfs_lookup_csum(trans, root, path,
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inode->i_ino, cur, 1);
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if (IS_ERR(item)) {
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cur += root->blocksize;
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continue;
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}
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leaf = btrfs_buffer_leaf(path->nodes[0]);
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slot = path->slots[0];
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btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
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item_size = btrfs_item_size(leaf->items + slot);
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num_csums = item_size / sizeof(struct btrfs_csum_item);
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found_end = key.offset + (num_csums << inode->i_blkbits);
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cur = found_end;
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if (found_end > end) {
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char *src;
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old_block = kmalloc(root->blocksize, GFP_NOFS);
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src = btrfs_item_ptr(leaf, slot, char);
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memcpy(old_block, src, item_size);
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}
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if (key.offset < start) {
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u64 new_size = (start - key.offset) >>
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inode->i_blkbits;
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new_size *= sizeof(struct btrfs_csum_item);
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ret = btrfs_truncate_item(trans, root, path, new_size);
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BUG_ON(ret);
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} else {
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btrfs_del_item(trans, root, path);
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}
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btrfs_release_path(root, path);
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if (found_end > end) {
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char *dst;
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int i;
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int new_size;
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num_csums = (found_end - end) >> inode->i_blkbits;
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new_size = num_csums * sizeof(struct btrfs_csum_item);
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key.offset = end;
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ret = btrfs_insert_empty_item(trans, root, path,
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&key, new_size);
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BUG_ON(ret);
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dst = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
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path->slots[0], char);
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memcpy(dst, old_block + item_size - new_size,
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new_size);
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item = (struct btrfs_csum_item *)dst;
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for (i = 0; i < num_csums; i++) {
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btrfs_set_csum_extent_offset(item, end);
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item++;
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}
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mark_buffer_dirty(path->nodes[0]);
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kfree(old_block);
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break;
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}
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}
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btrfs_free_path(path);
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return 0;
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}
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static int drop_extents(struct btrfs_trans_handle *trans,
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struct btrfs_root *root,
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struct inode *inode,
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u64 start, u64 end)
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{
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int ret;
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struct btrfs_key key;
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struct btrfs_leaf *leaf;
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int slot;
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struct btrfs_file_extent_item *extent;
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u64 extent_end;
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int keep;
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struct btrfs_file_extent_item old;
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struct btrfs_path *path;
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u64 search_start = start;
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int bookend;
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path = btrfs_alloc_path();
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if (!path)
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return -ENOMEM;
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search_again:
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printk("drop extent inode %lu start %Lu end %Lu\n", inode->i_ino, start, end);
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ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
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search_start, -1);
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if (ret != 0) {
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printk("lookup failed\n");
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goto out;
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}
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while(1) {
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keep = 0;
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bookend = 0;
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leaf = btrfs_buffer_leaf(path->nodes[0]);
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slot = path->slots[0];
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btrfs_disk_key_to_cpu(&key, &leaf->items[slot].key);
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printk("found key %Lu %Lu %u\n", key.objectid, key.offset, key.flags);
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extent = btrfs_item_ptr(leaf, slot,
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struct btrfs_file_extent_item);
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extent_end = key.offset +
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(btrfs_file_extent_num_blocks(extent) <<
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inode->i_blkbits);
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printk("extent end is %Lu\n", extent_end);
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if (key.offset >= end || key.objectid != inode->i_ino) {
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ret = 0;
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goto out;
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}
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if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY)
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goto next_leaf;
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if (end < extent_end && end >= key.offset) {
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memcpy(&old, extent, sizeof(old));
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ret = btrfs_inc_extent_ref(trans, root,
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btrfs_file_extent_disk_blocknr(&old),
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btrfs_file_extent_disk_num_blocks(&old));
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BUG_ON(ret);
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bookend = 1;
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}
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if (start > key.offset) {
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u64 new_num;
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/* truncate existing extent */
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keep = 1;
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WARN_ON(start & (root->blocksize - 1));
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new_num = (start - key.offset) >> inode->i_blkbits;
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printk("truncating existing extent, was %Lu ", btrfs_file_extent_num_blocks(extent));
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btrfs_set_file_extent_num_blocks(extent, new_num);
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printk("now %Lu\n", btrfs_file_extent_num_blocks(extent));
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mark_buffer_dirty(path->nodes[0]);
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}
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if (!keep) {
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u64 disk_blocknr;
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u64 disk_num_blocks;
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printk("del old\n");
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disk_blocknr = btrfs_file_extent_disk_blocknr(extent);
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disk_num_blocks =
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btrfs_file_extent_disk_num_blocks(extent);
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search_start = key.offset +
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(btrfs_file_extent_num_blocks(extent) <<
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inode->i_blkbits);
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ret = btrfs_del_item(trans, root, path);
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BUG_ON(ret);
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btrfs_release_path(root, path);
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ret = btrfs_free_extent(trans, root, disk_blocknr,
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disk_num_blocks, 0);
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BUG_ON(ret);
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if (!bookend && search_start >= end) {
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ret = 0;
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goto out;
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}
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if (!bookend)
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goto search_again;
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}
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if (bookend) {
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/* create bookend */
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struct btrfs_key ins;
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printk("bookend! extent end %Lu\n", extent_end);
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ins.objectid = inode->i_ino;
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ins.offset = end;
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ins.flags = 0;
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btrfs_set_key_type(&ins, BTRFS_EXTENT_DATA_KEY);
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btrfs_release_path(root, path);
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ret = drop_csums(trans, root, inode, start, end);
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BUG_ON(ret);
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ret = btrfs_insert_empty_item(trans, root, path, &ins,
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sizeof(*extent));
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BUG_ON(ret);
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extent = btrfs_item_ptr(
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btrfs_buffer_leaf(path->nodes[0]),
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path->slots[0],
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struct btrfs_file_extent_item);
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btrfs_set_file_extent_disk_blocknr(extent,
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btrfs_file_extent_disk_blocknr(&old));
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btrfs_set_file_extent_disk_num_blocks(extent,
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btrfs_file_extent_disk_num_blocks(&old));
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btrfs_set_file_extent_offset(extent,
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btrfs_file_extent_offset(&old) +
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((end - key.offset) >> inode->i_blkbits));
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WARN_ON(btrfs_file_extent_num_blocks(&old) <
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(end - key.offset) >> inode->i_blkbits);
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btrfs_set_file_extent_num_blocks(extent,
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btrfs_file_extent_num_blocks(&old) -
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((end - key.offset) >> inode->i_blkbits));
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btrfs_set_file_extent_generation(extent,
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btrfs_file_extent_generation(&old));
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printk("new bookend at offset %Lu, file_extent_offset %Lu, file_extent_num_blocks %Lu\n", end, btrfs_file_extent_offset(extent), btrfs_file_extent_num_blocks(extent));
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btrfs_mark_buffer_dirty(path->nodes[0]);
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ret = 0;
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goto out_nocsum;
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}
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next_leaf:
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if (slot >= btrfs_header_nritems(&leaf->header) - 1) {
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ret = btrfs_next_leaf(root, path);
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if (ret) {
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ret = 0;
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goto out;
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}
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} else {
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path->slots[0]++;
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}
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}
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out:
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ret = drop_csums(trans, root, inode, start, end);
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BUG_ON(ret);
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out_nocsum:
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btrfs_free_path(path);
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return ret;
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}
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static int prepare_pages(struct btrfs_root *root,
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struct file *file,
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struct page **pages,
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size_t num_pages,
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@@ -1289,7 +1527,6 @@ static int prepare_pages(struct btrfs_trans_handle *trans,
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struct inode *inode = file->f_path.dentry->d_inode;
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int offset;
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int err = 0;
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int ret;
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int this_write;
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struct buffer_head *bh;
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struct buffer_head *head;
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@@ -1305,18 +1542,21 @@ static int prepare_pages(struct btrfs_trans_handle *trans,
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}
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offset = pos & (PAGE_CACHE_SIZE -1);
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this_write = min(PAGE_CACHE_SIZE - offset, write_bytes);
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if (!PageUptodate(pages[i]) &&
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(pages[i]->index == first_index ||
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pages[i]->index == last_index) && pos < isize) {
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#if 0
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if ((pages[i]->index == first_index ||
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pages[i]->index == last_index) && pos < isize &&
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!PageUptodate(pages[i])) {
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ret = mpage_readpage(pages[i], btrfs_get_block);
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BUG_ON(ret);
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lock_page(pages[i]);
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}
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#endif
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create_empty_buffers(pages[i], root->fs_info->sb->s_blocksize,
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(1 << BH_Uptodate));
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head = page_buffers(pages[i]);
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bh = head;
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do {
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printk("mapping page %lu to block %Lu\n", pages[i]->index, alloc_extent_start);
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err = btrfs_map_bh_to_logical(root, bh,
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alloc_extent_start);
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BUG_ON(err);
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@@ -1351,7 +1591,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
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int ret = 0;
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struct inode *inode = file->f_path.dentry->d_inode;
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struct btrfs_root *root = BTRFS_I(inode)->root;
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struct page *pages[1];
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struct page *pages[8];
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unsigned long first_index;
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unsigned long last_index;
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u64 start_pos;
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@@ -1359,6 +1599,7 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
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u64 alloc_extent_start;
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u64 orig_extent_start;
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struct btrfs_trans_handle *trans;
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struct btrfs_key ins;
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if (file->f_flags & O_DIRECT)
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return -EINVAL;
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@@ -1390,16 +1631,24 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
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trans = btrfs_start_transaction(root, 1);
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if (!trans) {
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err = -ENOMEM;
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mutex_unlock(&root->fs_info->fs_mutex);
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goto out_unlock;
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}
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ret = btrfs_alloc_file_extent(trans, root, inode->i_ino,
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start_pos, num_blocks, 1,
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&alloc_extent_start);
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BUG_ON(ret);
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if (start_pos < inode->i_size) {
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ret = drop_extents(trans, root, inode,
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start_pos,
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(pos + count + root->blocksize -1) &
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~(root->blocksize - 1));
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}
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orig_extent_start = start_pos;
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ret = btrfs_end_transaction(trans, root);
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ret = btrfs_alloc_extent(trans, root, num_blocks, 1,
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(u64)-1, &ins);
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BUG_ON(ret);
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ret = btrfs_insert_file_extent(trans, root, inode->i_ino,
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start_pos, ins.objectid, ins.offset);
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BUG_ON(ret);
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alloc_extent_start = ins.objectid;
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ret = btrfs_end_transaction(trans, root);
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mutex_unlock(&root->fs_info->fs_mutex);
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while(count > 0) {
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@@ -1407,16 +1656,21 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf,
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size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
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size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
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PAGE_CACHE_SHIFT;
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ret = prepare_pages(NULL, root, file, pages, num_pages,
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printk("num_pages is %lu\n", num_pages);
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memset(pages, 0, sizeof(pages));
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ret = prepare_pages(root, file, pages, num_pages,
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pos, first_index, last_index,
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write_bytes, alloc_extent_start);
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BUG_ON(ret);
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/* FIXME blocks != pagesize */
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alloc_extent_start += num_pages;
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ret = btrfs_copy_from_user(pos, num_pages,
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write_bytes, pages, buf);
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BUG_ON(ret);
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printk("2num_pages is %lu\n", num_pages);
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ret = dirty_and_release_pages(NULL, root, file, pages,
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num_pages, orig_extent_start,
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pos, write_bytes);
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