diff options
Diffstat (limited to 'fs/ext4/inline.c')
| -rw-r--r-- | fs/ext4/inline.c | 177 |
1 files changed, 177 insertions, 0 deletions
diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c index 01274b1e7d4..65f7ffb5437 100644 --- a/fs/ext4/inline.c +++ b/fs/ext4/inline.c @@ -771,6 +771,183 @@ ext4_journalled_write_inline_data(struct inode *inode, return iloc.bh; } +/* + * Try to make the page cache and handle ready for the inline data case. + * We can call this function in 2 cases: + * 1. The inode is created and the first write exceeds inline size. We can + * clear the inode state safely. + * 2. The inode has inline data, then we need to read the data, make it + * update and dirty so that ext4_da_writepages can handle it. We don't + * need to start the journal since the file's metatdata isn't changed now. + */ +static int ext4_da_convert_inline_data_to_extent(struct address_space *mapping, + struct inode *inode, + unsigned flags, + void **fsdata) +{ + int ret = 0, inline_size; + struct page *page; + + page = grab_cache_page_write_begin(mapping, 0, flags); + if (!page) + return -ENOMEM; + + down_read(&EXT4_I(inode)->xattr_sem); + if (!ext4_has_inline_data(inode)) { + ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); + goto out; + } + + inline_size = ext4_get_inline_size(inode); + + if (!PageUptodate(page)) { + ret = ext4_read_inline_page(inode, page); + if (ret < 0) + goto out; + } + + ret = __block_write_begin(page, 0, inline_size, + ext4_da_get_block_prep); + if (ret) { + ext4_truncate_failed_write(inode); + goto out; + } + + SetPageDirty(page); + SetPageUptodate(page); + ext4_clear_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA); + *fsdata = (void *)CONVERT_INLINE_DATA; + +out: + up_read(&EXT4_I(inode)->xattr_sem); + if (page) { + unlock_page(page); + page_cache_release(page); + } + return ret; +} + +/* + * Prepare the write for the inline data. + * If the the data can be written into the inode, we just read + * the page and make it uptodate, and start the journal. + * Otherwise read the page, makes it dirty so that it can be + * handle in writepages(the i_disksize update is left to the + * normal ext4_da_write_end). + */ +int ext4_da_write_inline_data_begin(struct address_space *mapping, + struct inode *inode, + loff_t pos, unsigned len, + unsigned flags, + struct page **pagep, + void **fsdata) +{ + int ret, inline_size; + handle_t *handle; + struct page *page; + struct ext4_iloc iloc; + + ret = ext4_get_inode_loc(inode, &iloc); + if (ret) + return ret; + + handle = ext4_journal_start(inode, 1); + if (IS_ERR(handle)) { + ret = PTR_ERR(handle); + handle = NULL; + goto out; + } + + inline_size = ext4_get_max_inline_size(inode); + + ret = -ENOSPC; + if (inline_size >= pos + len) { + ret = ext4_prepare_inline_data(handle, inode, pos + len); + if (ret && ret != -ENOSPC) + goto out; + } + + if (ret == -ENOSPC) { + ret = ext4_da_convert_inline_data_to_extent(mapping, + inode, + flags, + fsdata); + goto out; + } + + /* + * We cannot recurse into the filesystem as the transaction + * is already started. + */ + flags |= AOP_FLAG_NOFS; + + page = grab_cache_page_write_begin(mapping, 0, flags); + if (!page) { + ret = -ENOMEM; + goto out; + } + + down_read(&EXT4_I(inode)->xattr_sem); + if (!ext4_has_inline_data(inode)) { + ret = 0; + goto out_release_page; + } + + if (!PageUptodate(page)) { + ret = ext4_read_inline_page(inode, page); + if (ret < 0) + goto out_release_page; + } + + up_read(&EXT4_I(inode)->xattr_sem); + *pagep = page; + handle = NULL; + brelse(iloc.bh); + return 1; +out_release_page: + up_read(&EXT4_I(inode)->xattr_sem); + unlock_page(page); + page_cache_release(page); +out: + if (handle) + ext4_journal_stop(handle); + brelse(iloc.bh); + return ret; +} + +int ext4_da_write_inline_data_end(struct inode *inode, loff_t pos, + unsigned len, unsigned copied, + struct page *page) +{ + int i_size_changed = 0; + + copied = ext4_write_inline_data_end(inode, pos, len, copied, page); + + /* + * No need to use i_size_read() here, the i_size + * cannot change under us because we hold i_mutex. + * + * But it's important to update i_size while still holding page lock: + * page writeout could otherwise come in and zero beyond i_size. + */ + if (pos+copied > inode->i_size) { + i_size_write(inode, pos+copied); + i_size_changed = 1; + } + unlock_page(page); + page_cache_release(page); + + /* + * Don't mark the inode dirty under page lock. First, it unnecessarily + * makes the holding time of page lock longer. Second, it forces lock + * ordering of page lock and transaction start for journaling + * filesystems. + */ + if (i_size_changed) + mark_inode_dirty(inode); + + return copied; +} int ext4_destroy_inline_data(handle_t *handle, struct inode *inode) { |