diff options
| -rw-r--r-- | fs/btrfs/send.c | 175 |
1 files changed, 72 insertions, 103 deletions
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 0a894399be1..e26a3a62fd3 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -121,7 +121,6 @@ struct send_ctx { struct list_head name_cache_list; int name_cache_size; - struct file *cur_inode_filp; char *read_buf; }; @@ -2120,77 +2119,6 @@ out: } /* - * Called for regular files when sending extents data. Opens a struct file - * to read from the file. - */ -static int open_cur_inode_file(struct send_ctx *sctx) -{ - int ret = 0; - struct btrfs_key key; - struct path path; - struct inode *inode; - struct dentry *dentry; - struct file *filp; - int new = 0; - - if (sctx->cur_inode_filp) - goto out; - - key.objectid = sctx->cur_ino; - key.type = BTRFS_INODE_ITEM_KEY; - key.offset = 0; - - inode = btrfs_iget(sctx->send_root->fs_info->sb, &key, sctx->send_root, - &new); - if (IS_ERR(inode)) { - ret = PTR_ERR(inode); - goto out; - } - - dentry = d_obtain_alias(inode); - inode = NULL; - if (IS_ERR(dentry)) { - ret = PTR_ERR(dentry); - goto out; - } - - path.mnt = sctx->mnt; - path.dentry = dentry; - filp = dentry_open(&path, O_RDONLY | O_LARGEFILE, current_cred()); - dput(dentry); - dentry = NULL; - if (IS_ERR(filp)) { - ret = PTR_ERR(filp); - goto out; - } - sctx->cur_inode_filp = filp; - -out: - /* - * no xxxput required here as every vfs op - * does it by itself on failure - */ - return ret; -} - -/* - * Closes the struct file that was created in open_cur_inode_file - */ -static int close_cur_inode_file(struct send_ctx *sctx) -{ - int ret = 0; - - if (!sctx->cur_inode_filp) - goto out; - - ret = filp_close(sctx->cur_inode_filp, NULL); - sctx->cur_inode_filp = NULL; - -out: - return ret; -} - -/* * Sends a BTRFS_SEND_C_SUBVOL command/item to userspace */ static int send_subvol_begin(struct send_ctx *sctx) @@ -3622,6 +3550,72 @@ out: return ret; } +static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len) +{ + struct btrfs_root *root = sctx->send_root; + struct btrfs_fs_info *fs_info = root->fs_info; + struct inode *inode; + struct page *page; + char *addr; + struct btrfs_key key; + pgoff_t index = offset >> PAGE_CACHE_SHIFT; + pgoff_t last_index; + unsigned pg_offset = offset & ~PAGE_CACHE_MASK; + ssize_t ret = 0; + + key.objectid = sctx->cur_ino; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + + inode = btrfs_iget(fs_info->sb, &key, root, NULL); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + if (offset + len > i_size_read(inode)) { + if (offset > i_size_read(inode)) + len = 0; + else + len = offset - i_size_read(inode); + } + if (len == 0) + goto out; + + last_index = (offset + len - 1) >> PAGE_CACHE_SHIFT; + while (index <= last_index) { + unsigned cur_len = min_t(unsigned, len, + PAGE_CACHE_SIZE - pg_offset); + page = find_or_create_page(inode->i_mapping, index, GFP_NOFS); + if (!page) { + ret = -ENOMEM; + break; + } + + if (!PageUptodate(page)) { + btrfs_readpage(NULL, page); + lock_page(page); + if (!PageUptodate(page)) { + unlock_page(page); + page_cache_release(page); + ret = -EIO; + break; + } + } + + addr = kmap(page); + memcpy(sctx->read_buf + ret, addr + pg_offset, cur_len); + kunmap(page); + unlock_page(page); + page_cache_release(page); + index++; + pg_offset = 0; + len -= cur_len; + ret += cur_len; + } +out: + iput(inode); + return ret; +} + /* * Read some bytes from the current inode/file and send a write command to * user space. @@ -3630,35 +3624,20 @@ static int send_write(struct send_ctx *sctx, u64 offset, u32 len) { int ret = 0; struct fs_path *p; - loff_t pos = offset; - int num_read = 0; - mm_segment_t old_fs; + ssize_t num_read = 0; p = fs_path_alloc(); if (!p) return -ENOMEM; - /* - * vfs normally only accepts user space buffers for security reasons. - * we only read from the file and also only provide the read_buf buffer - * to vfs. As this buffer does not come from a user space call, it's - * ok to temporary allow kernel space buffers. - */ - old_fs = get_fs(); - set_fs(KERNEL_DS); - verbose_printk("btrfs: send_write offset=%llu, len=%d\n", offset, len); - ret = open_cur_inode_file(sctx); - if (ret < 0) - goto out; - - ret = vfs_read(sctx->cur_inode_filp, sctx->read_buf, len, &pos); - if (ret < 0) - goto out; - num_read = ret; - if (!num_read) + num_read = fill_read_buf(sctx, offset, len); + if (num_read <= 0) { + if (num_read < 0) + ret = num_read; goto out; + } ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE); if (ret < 0) @@ -3677,7 +3656,6 @@ verbose_printk("btrfs: send_write offset=%llu, len=%d\n", offset, len); tlv_put_failure: out: fs_path_free(p); - set_fs(old_fs); if (ret < 0) return ret; return num_read; @@ -4222,10 +4200,6 @@ static int changed_inode(struct send_ctx *sctx, u64 left_gen = 0; u64 right_gen = 0; - ret = close_cur_inode_file(sctx); - if (ret < 0) - goto out; - sctx->cur_ino = key->objectid; sctx->cur_inode_new_gen = 0; @@ -4686,11 +4660,6 @@ static int send_subvol(struct send_ctx *sctx) } out: - if (!ret) - ret = close_cur_inode_file(sctx); - else - close_cur_inode_file(sctx); - free_recorded_refs(sctx); return ret; } |