From patchwork Sun Jul 22 07:59:45 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [RFC, 09/10, v1, RESEND] ext4: don't need to writeout all dirty pages in punch hole Date: Sat, 21 Jul 2012 21:59:45 -0000 From: Zheng Liu X-Patchwork-Id: 172500 Message-Id: <1342943986-12413-10-git-send-email-wenqing.lz@taobao.com> To: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org Cc: xiaoqiangnk@gmail.com, achender@linux.vnet.ibm.com, wenqing.lz@taobao.com From: Zheng Liu Now we don't need to writeout all dirty pages when punching a hole. The i_mutex locking is taken to avoid concurrent writes. In truncate_pagecache_range, all pages in this hole is released, and ext4_es_remove_space is called to update extent status tree. Signed-off-by: Zheng Liu --- fs/ext4/extents.c | 28 ++++++++++++---------------- 1 files changed, 12 insertions(+), 16 deletions(-) diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index f2c5294..2a526b4 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4529,9 +4529,11 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) loff_t first_page_offset, last_page_offset; int credits, err = 0; + mutex_lock(&inode->i_mutex); + /* No need to punch hole beyond i_size */ if (offset >= inode->i_size) - return 0; + goto error; /* * If the hole extends beyond i_size, set the hole @@ -4549,18 +4551,6 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) first_page_offset = first_page << PAGE_CACHE_SHIFT; last_page_offset = last_page << PAGE_CACHE_SHIFT; - /* - * Write out all dirty pages to avoid race conditions - * Then release them. - */ - if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { - err = filemap_write_and_wait_range(mapping, - offset, offset + length - 1); - - if (err) - return err; - } - /* Now release the pages */ if (last_page_offset > first_page_offset) { truncate_pagecache_range(inode, first_page_offset, @@ -4572,12 +4562,14 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) credits = ext4_writepage_trans_blocks(inode); handle = ext4_journal_start(inode, credits); - if (IS_ERR(handle)) - return PTR_ERR(handle); + if (IS_ERR(handle)) { + err = PTR_ERR(handle); + goto error; + } err = ext4_orphan_add(handle, inode); if (err) - goto out; + goto error; /* * Now we need to zero out the non-page-aligned data in the @@ -4652,6 +4644,8 @@ int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length) ext4_ext_invalidate_cache(inode); ext4_discard_preallocations(inode); + err = ext4_es_remove_space(inode, first_block, + stop_block - first_block); err = ext4_ext_remove_space(inode, first_block, stop_block - 1); ext4_ext_invalidate_cache(inode); @@ -4667,6 +4661,8 @@ out: inode->i_mtime = inode->i_ctime = ext4_current_time(inode); ext4_mark_inode_dirty(handle, inode); ext4_journal_stop(handle); +error: + mutex_unlock(&inode->i_mutex); return err; } int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,