From: jon ernst Subject: Re: [PATCH 5/6 v2] ext4: Introduce FALLOC_FL_ZERO_RANGE flag for fallocate Date: Wed, 26 Feb 2014 23:41:15 -0500 Message-ID: References: <1393355679-11160-1-git-send-email-lczerner@redhat.com> <1393355679-11160-6-git-send-email-lczerner@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: linux-fsdevel@vger.kernel.org, "linux-ext4@vger.kernel.org List" , Theodore Ts'o , xfs@oss.sgi.com To: Lukas Czerner Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com List-Id: linux-ext4.vger.kernel.org On Wed, Feb 26, 2014 at 1:00 AM, jon ernst wrote: > On Tue, Feb 25, 2014 at 2:14 PM, Lukas Czerner wrote: >> Introduce new FALLOC_FL_ZERO_RANGE flag for fallocate. This has the same >> functionality as xfs ioctl XFS_IOC_ZERO_RANGE. >> >> It can be used to convert a range of file to zeros preferably without >> issuing data IO. Blocks should be preallocated for the regions that span >> holes in the file, and the entire range is preferable converted to >> unwritten extents >> >> This can be also used to preallocate blocks past EOF in the same way as >> with fallocate. Flag FALLOC_FL_KEEP_SIZE which should cause the inode >> size to remain the same. >> >> Also add appropriate tracepoints. >> >> Signed-off-by: Lukas Czerner >> --- >> fs/ext4/ext4.h | 2 + >> fs/ext4/extents.c | 270 +++++++++++++++++++++++++++++++++++++++++--- >> fs/ext4/inode.c | 17 ++- >> include/trace/events/ext4.h | 64 +++++------ >> static int >> +ext4_ext_convert_initialized_extent(handle_t *handle, struct inode *inode, >> + struct ext4_map_blocks *map, >> + struct ext4_ext_path *path, int flags, >> + unsigned int allocated, ext4_fsblk_t newblock) >> +{ >> + int ret = 0; >> + int err = 0; >> + >> + /* >> + * Make sure that the extent is no bigger than we support with >> + * uninitialized extent >> + */ >> + if (map->m_len > EXT_UNINIT_MAX_LEN) >> + map->m_len = EXT_UNINIT_MAX_LEN / 2; > Pardon my possible dumb question. Why do you use "EXT_UNINIT_MAX_LEN/ 2;" here instead of "EXT_UNINIT_MAX_LEN" I don't see the reason why we can't use EXT_UNINIT_MAX_LEN here. (resend, Ping on this question, thank you!) Thanks! Jon _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs