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Btrfs: early inline file data code

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Signed-off-by: Chris Mason <chris.mason@oracle.com>
This commit is contained in:
Chris Mason 2007-04-04 09:36:31 -04:00 committed by David Woodhouse
parent 9d64272cd3
commit df24a2b9c9
2 changed files with 248 additions and 10 deletions
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18
fs/btrfs/ctree.c
View File

@ -16,21 +16,26 @@ static int balance_node_right(struct btrfs_trans_handle *trans, struct
static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root,
struct btrfs_path *path, int level, int slot);
inline void btrfs_init_path(struct btrfs_path *p)
{
memset(p, 0, sizeof(*p));
}
struct btrfs_path *btrfs_alloc_path(void)
{
return kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
struct btrfs_path *path;
path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
if (path)
btrfs_init_path(path);
return path;
}
void btrfs_free_path(struct btrfs_path *p)
{
btrfs_release_path(NULL, p);
kmem_cache_free(btrfs_path_cachep, p);
}
inline void btrfs_init_path(struct btrfs_path *p)
{
memset(p, 0, sizeof(*p));
}
void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
{
int i;
@ -77,6 +82,7 @@ static int btrfs_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root
btrfs_free_extent(trans, root, buf->b_blocknr, 1, 1);
}
btrfs_block_release(root, buf);
mark_buffer_dirty(cow);
*cow_ret = cow;
return 0;
}

240
fs/btrfs/super.c
View File

@ -816,6 +816,73 @@ printk("btrfs sync_fs\n");
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 @@ static int btrfs_get_block(struct inode *inode, sector_t iblock,
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 @@ out:
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 file_operations btrfs_dir_file_operations = {
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 inode_operations btrfs_file_inode_operations = {
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,
};