From: Anatol Pomozov Subject: Re: [PATCH 2/2] ext4: Remove code duplication in ext4_get_block_write_nolock() Date: Mon, 15 Oct 2012 12:14:37 -0700 Message-ID: References: <1350328009-22740-1-git-send-email-anatol.pomozov@gmail.com> <1350328009-22740-2-git-send-email-anatol.pomozov@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: Anatol Pomozov To: tytso@mit.edu, wenqing.lz@taobao.com, linux-ext4@vger.kernel.org Return-path: Received: from mail-la0-f46.google.com ([209.85.215.46]:55786 "EHLO mail-la0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754431Ab2JOTOj (ORCPT ); Mon, 15 Oct 2012 15:14:39 -0400 Received: by mail-la0-f46.google.com with SMTP id h6so3648077lag.19 for ; Mon, 15 Oct 2012 12:14:37 -0700 (PDT) In-Reply-To: <1350328009-22740-2-git-send-email-anatol.pomozov@gmail.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Mon, Oct 15, 2012 at 12:06 PM, Anatol Pomozov wrote: > 729f52c6be51013 introduced function ext4_get_block_write_nolock() that > is very similar to _ext4_get_block(). Eliminate code duplication > by passing different flags to _ext4_get_block() > > Tested: xfs tests > > Signed-off-by: Anatol Pomozov > --- > fs/ext4/inode.c | 63 ++++++++++++++++++++++----------------------------------- > 1 file changed, 24 insertions(+), 39 deletions(-) > > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index b3c243b..9829c3d 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -683,7 +683,7 @@ static int _ext4_get_block(struct inode *inode, sector_t iblock, > map.m_lblk = iblock; > map.m_len = bh->b_size >> inode->i_blkbits; > > - if (flags && !handle) { > + if (flags && !(flags | EXT4_GET_BLOCKS_NO_LOCK) && !handle) { > /* Direct IO write... */ > if (map.m_len > DIO_MAX_BLOCKS) > map.m_len = DIO_MAX_BLOCKS; > @@ -880,6 +880,8 @@ static int do_journal_get_write_access(handle_t *handle, > > static int ext4_get_block_write(struct inode *inode, sector_t iblock, > struct buffer_head *bh_result, int create); > +static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock, > + struct buffer_head *bh_result, int create); > static int ext4_write_begin(struct file *file, struct address_space *mapping, > loff_t pos, unsigned len, unsigned flags, > struct page **pagep, void **fsdata) > @@ -2850,29 +2852,12 @@ static int ext4_get_block_write(struct inode *inode, sector_t iblock, > } > > static int ext4_get_block_write_nolock(struct inode *inode, sector_t iblock, > - struct buffer_head *bh_result, int flags) > + struct buffer_head *bh_result, int create) > { > - handle_t *handle = ext4_journal_current_handle(); > - struct ext4_map_blocks map; > - int ret = 0; > - > - ext4_debug("ext4_get_block_write_nolock: inode %lu, flag %d\n", > - inode->i_ino, flags); > - > - flags = EXT4_GET_BLOCKS_NO_LOCK; > - > - map.m_lblk = iblock; > - map.m_len = bh_result->b_size >> inode->i_blkbits; > - > - ret = ext4_map_blocks(handle, inode, &map, flags); > - if (ret > 0) { > - map_bh(bh_result, inode->i_sb, map.m_pblk); > - bh_result->b_state = (bh_result->b_state & ~EXT4_MAP_FLAGS) | > - map.m_flags; > - bh_result->b_size = inode->i_sb->s_blocksize * map.m_len; > - ret = 0; > - } > - return ret; > + ext4_debug("ext4_get_block_write_nolock: inode %lu, create flag %d\n", > + inode->i_ino, create); > + return _ext4_get_block(inode, iblock, bh_result, > + EXT4_GET_BLOCKS_NO_LOCK); > } > > static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, > @@ -3003,6 +2988,8 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb, > loff_t final_size = offset + count; > if (rw == WRITE && final_size <= inode->i_size) { > int overwrite = 0; > + get_block_t *get_block_func = NULL; > + int dio_flags = 0; > > BUG_ON(iocb->private == NULL); > > @@ -3056,22 +3043,20 @@ static ssize_t ext4_ext_direct_IO(int rw, struct kiocb *iocb, > ext4_inode_aio_set(inode, io_end); > } > > - if (overwrite) > - ret = __blockdev_direct_IO(rw, iocb, inode, > - inode->i_sb->s_bdev, iov, > - offset, nr_segs, > - ext4_get_block_write_nolock, > - ext4_end_io_dio, > - NULL, > - 0); > - else > - ret = __blockdev_direct_IO(rw, iocb, inode, > - inode->i_sb->s_bdev, iov, > - offset, nr_segs, > - ext4_get_block_write, > - ext4_end_io_dio, > - NULL, > - DIO_LOCKING); > + if (overwrite) { > + get_block_func = ext4_get_block_write_nolock; Ideally if block layer (function __blockdev_direct_IO) accepted some user-data (e.g. flag) and later passed it back to callback function (i.e. ext4_get_block_write). In this case we do not need two functions ext4_get_block_write/ext4_get_block_write_nolock. > + } else { > + get_block_func = ext4_get_block_write; > + dio_flags = DIO_LOCKING; > + } > + ret = __blockdev_direct_IO(rw, iocb, inode, > + inode->i_sb->s_bdev, iov, > + offset, nr_segs, > + get_block_func, > + ext4_end_io_dio, > + NULL, > + dio_flags); > + > if (iocb->private) > ext4_inode_aio_set(inode, NULL); > /* > -- > 1.8.0.rc1 >