Btrfs: early inline file data code
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index fbc26ea..68127b8 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -816,6 +816,73 @@
return 0;
}
+static int btrfs_get_block_inline(struct inode *inode, sector_t iblock,
+ struct buffer_head *result, int create)
+{
+ struct btrfs_root *root = btrfs_sb(inode->i_sb);
+ struct btrfs_path *path;
+ struct btrfs_key key;
+ struct btrfs_leaf *leaf;
+ int num_bytes = result->b_size;
+ int item_size;
+ int ret;
+ u64 pos;
+ char *ptr;
+ int copy_size;
+ int err = 0;
+ char *safe_ptr;
+ char *data_ptr;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+
+ WARN_ON(create);
+ if (create) {
+ return 0;
+ }
+ pos = iblock << inode->i_blkbits;
+ key.objectid = inode->i_ino;
+ key.flags = 0;
+ btrfs_set_key_type(&key, BTRFS_INLINE_DATA_KEY);
+ ptr = kmap(result->b_page);
+ safe_ptr = ptr;
+ ptr += (pos & (PAGE_CACHE_SIZE -1));
+again:
+ key.offset = pos;
+ ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
+ if (ret) {
+ if (ret < 0)
+ err = ret;
+ else
+ err = 0;
+ goto out;
+ }
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ item_size = btrfs_item_size(leaf->items + path->slots[0]);
+ copy_size = min(num_bytes, item_size);
+ data_ptr = btrfs_item_ptr(leaf, path->slots[0], char);
+ WARN_ON(safe_ptr + PAGE_CACHE_SIZE < ptr + copy_size);
+ memcpy(ptr, data_ptr, copy_size);
+ pos += copy_size;
+ num_bytes -= copy_size;
+ WARN_ON(num_bytes < 0);
+ ptr += copy_size;
+ btrfs_release_path(root, path);
+ if (num_bytes != 0) {
+ if (pos >= i_size_read(inode))
+ memset(ptr, 0, num_bytes);
+ else
+ goto again;
+ }
+ set_buffer_uptodate(result);
+ map_bh(result, inode->i_sb, 0);
+ err = 0;
+out:
+ btrfs_free_path(path);
+ kunmap(result->b_page);
+ return err;
+}
+
static int btrfs_get_block_lock(struct inode *inode, sector_t iblock,
struct buffer_head *result, int create)
{
@@ -918,7 +985,8 @@
int err;
struct btrfs_root *root = btrfs_sb(inode->i_sb);
mutex_lock(&root->fs_info->fs_mutex);
- err = btrfs_get_block_lock(inode, iblock, result, create);
+ // err = btrfs_get_block_lock(inode, iblock, result, create);
+ err = btrfs_get_block_inline(inode, iblock, result, create);
mutex_unlock(&root->fs_info->fs_mutex);
return err;
}
@@ -1177,6 +1245,170 @@
return num_written ? num_written : err;
}
+static ssize_t inline_one_page(struct btrfs_root *root, struct inode *inode,
+ struct page *page, loff_t pos,
+ size_t offset, size_t write_bytes)
+{
+ struct btrfs_path *path;
+ struct btrfs_trans_handle *trans;
+ struct btrfs_key key;
+ struct btrfs_leaf *leaf;
+ struct btrfs_key found_key;
+ int ret;
+ size_t copy_size = 0;
+ char *dst = NULL;
+ int err = 0;
+ size_t num_written = 0;
+
+ path = btrfs_alloc_path();
+ BUG_ON(!path);
+ mutex_lock(&root->fs_info->fs_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ key.objectid = inode->i_ino;
+ key.flags = 0;
+ btrfs_set_key_type(&key, BTRFS_INLINE_DATA_KEY);
+
+again:
+ key.offset = pos;
+ ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
+ if (ret < 0) {
+ err = ret;
+ goto out;
+ }
+ if (ret == 0) {
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ btrfs_disk_key_to_cpu(&found_key,
+ &leaf->items[path->slots[0]].key);
+ copy_size = btrfs_item_size(leaf->items + path->slots[0]);
+ dst = btrfs_item_ptr(leaf, path->slots[0], char);
+ copy_size = min(write_bytes, copy_size);
+ goto copyit;
+ } else {
+ int slot = path->slots[0];
+ if (slot > 0) {
+ slot--;
+ }
+ // FIXME find max key
+ leaf = btrfs_buffer_leaf(path->nodes[0]);
+ btrfs_disk_key_to_cpu(&found_key,
+ &leaf->items[slot].key);
+ if (found_key.objectid != inode->i_ino)
+ goto insert;
+ if (btrfs_key_type(&found_key) != BTRFS_INLINE_DATA_KEY)
+ goto insert;
+ copy_size = btrfs_item_size(leaf->items + slot);
+ if (found_key.offset + copy_size <= pos)
+ goto insert;
+ dst = btrfs_item_ptr(leaf, path->slots[0], char);
+ dst += pos - found_key.offset;
+ copy_size = copy_size - (pos - found_key.offset);
+ BUG_ON(copy_size < 0);
+ copy_size = min(write_bytes, copy_size);
+ WARN_ON(copy_size == 0);
+ goto copyit;
+ }
+insert:
+ btrfs_release_path(root, path);
+ copy_size = min(write_bytes, (size_t)512);
+ ret = btrfs_insert_empty_item(trans, root, path, &key, copy_size);
+ BUG_ON(ret);
+ dst = btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+ path->slots[0], char);
+copyit:
+ WARN_ON(copy_size == 0);
+ WARN_ON(dst + copy_size >
+ btrfs_item_ptr(btrfs_buffer_leaf(path->nodes[0]),
+ path->slots[0], char) +
+ btrfs_item_size(btrfs_buffer_leaf(path->nodes[0])->items +
+ path->slots[0]));
+ btrfs_memcpy(root, path->nodes[0]->b_data, dst,
+ page_address(page) + offset, copy_size);
+ mark_buffer_dirty(path->nodes[0]);
+ btrfs_release_path(root, path);
+ pos += copy_size;
+ offset += copy_size;
+ num_written += copy_size;
+ write_bytes -= copy_size;
+ if (write_bytes)
+ goto again;
+out:
+ btrfs_free_path(path);
+ ret = btrfs_end_transaction(trans, root);
+ BUG_ON(ret);
+ mutex_unlock(&root->fs_info->fs_mutex);
+ return num_written ? num_written : err;
+}
+
+static ssize_t btrfs_file_inline_write(struct file *file,
+ const char __user *buf,
+ size_t count, loff_t *ppos)
+{
+ loff_t pos;
+ size_t num_written = 0;
+ int err = 0;
+ int ret = 0;
+ struct inode *inode = file->f_path.dentry->d_inode;
+ struct btrfs_root *root = btrfs_sb(inode->i_sb);
+ unsigned long page_index;
+
+ if (file->f_flags & O_DIRECT)
+ return -EINVAL;
+ pos = *ppos;
+
+ vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
+ current->backing_dev_info = inode->i_mapping->backing_dev_info;
+ err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
+ if (err)
+ goto out;
+ if (count == 0)
+ goto out;
+ err = remove_suid(file->f_path.dentry);
+ if (err)
+ goto out;
+ file_update_time(file);
+ mutex_lock(&inode->i_mutex);
+ while(count > 0) {
+ size_t offset = pos & (PAGE_CACHE_SIZE - 1);
+ size_t write_bytes = min(count, PAGE_CACHE_SIZE - offset);
+ struct page *page;
+
+ page_index = pos >> PAGE_CACHE_SHIFT;
+ page = grab_cache_page(inode->i_mapping, page_index);
+ if (!PageUptodate(page)) {
+ ret = mpage_readpage(page, btrfs_get_block);
+ BUG_ON(ret);
+ lock_page(page);
+ }
+ ret = btrfs_copy_from_user(pos, 1,
+ write_bytes, &page, buf);
+ BUG_ON(ret);
+ write_bytes = inline_one_page(root, inode, page, pos,
+ offset, write_bytes);
+ SetPageUptodate(page);
+ if (write_bytes > 0 && pos + write_bytes > inode->i_size) {
+ i_size_write(inode, pos + write_bytes);
+ mark_inode_dirty(inode);
+ }
+ page_cache_release(page);
+ unlock_page(page);
+ if (write_bytes < 0)
+ goto out_unlock;
+ buf += write_bytes;
+ count -= write_bytes;
+ pos += write_bytes;
+ num_written += write_bytes;
+
+ balance_dirty_pages_ratelimited(inode->i_mapping);
+ cond_resched();
+ }
+out_unlock:
+ mutex_unlock(&inode->i_mutex);
+out:
+ *ppos = pos;
+ current->backing_dev_info = NULL;
+ return num_written ? num_written : err;
+}
+
static int btrfs_read_actor(read_descriptor_t *desc, struct page *page,
unsigned long offset, unsigned long size)
{
@@ -1420,7 +1652,7 @@
static struct address_space_operations btrfs_aops = {
.readpage = btrfs_readpage,
- .readpages = btrfs_readpages,
+ // .readpages = btrfs_readpages,
.writepage = btrfs_writepage,
.sync_page = block_sync_page,
.prepare_write = btrfs_prepare_write,
@@ -1434,8 +1666,8 @@
static struct file_operations btrfs_file_operations = {
.llseek = generic_file_llseek,
.read = do_sync_read,
- .aio_read = btrfs_file_aio_read,
- .write = btrfs_file_write,
+ .aio_read = generic_file_aio_read,
+ .write = btrfs_file_inline_write,
.mmap = generic_file_mmap,
.open = generic_file_open,
};