2 files changed, 248 insertions, 10 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 453ce835209a..9ef65e2ecf51 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -16,19 +16,24 @@ 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);
 
-struct btrfs_path *btrfs_alloc_path(void)
+inline void btrfs_init_path(struct btrfs_path *p)
 {
-        return kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
+        memset(p, 0, sizeof(*p));
 }
 
-void btrfs_free_path(struct btrfs_path *p)
+struct btrfs_path *btrfs_alloc_path(void)
 {
-        kmem_cache_free(btrfs_path_cachep, p);
+        struct btrfs_path *path;
+        path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS);
+        if (path)
+                btrfs_init_path(path);
+        return path;
 }
 
-inline void btrfs_init_path(struct btrfs_path *p)
+void btrfs_free_path(struct btrfs_path *p)
 {
-        memset(p, 0, sizeof(*p));
+        btrfs_release_path(NULL, p);
+        kmem_cache_free(btrfs_path_cachep, p);
 }
 
 void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
@@ -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;
 }
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index fbc26eafc58c..68127b8462ab 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -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,
 };