From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54249) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WQcvi-000703-BX for qemu-devel@nongnu.org; Thu, 20 Mar 2014 09:22:47 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WQcvb-0007iA-2v for qemu-devel@nongnu.org; Thu, 20 Mar 2014 09:22:42 -0400 Received: from mx1.redhat.com ([209.132.183.28]:55770) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WQcva-0007hw-Rh for qemu-devel@nongnu.org; Thu, 20 Mar 2014 09:22:35 -0400 Date: Thu, 20 Mar 2014 14:22:19 +0100 From: Kevin Wolf Message-ID: <20140320132219.GA3450@noname.redhat.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [PATCH v7 for 2.0 3/4] raw-posix: Add full image preallocation option List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Hu Tao Cc: Stefan Hajnoczi , qemu-devel@nongnu.org Am 17.03.2014 um 07:53 hat Hu Tao geschrieben: > This patch adds a new option preallocation for raw format, and implements > full preallocation. > > Signed-off-by: Hu Tao > --- > block/raw-posix.c | 43 +++++++++++++++++++++++++++++++++++-------- > 1 file changed, 35 insertions(+), 8 deletions(-) > > diff --git a/block/raw-posix.c b/block/raw-posix.c > index a363b71..e004ff8 100644 > --- a/block/raw-posix.c > +++ b/block/raw-posix.c > @@ -1240,6 +1240,7 @@ static int raw_create(const char *filename, QEMUOptionParameter *options, > int fd; > int result = 0; > int64_t total_size = 0; > + PreallocMode prealloc = PREALLOC_MODE_OFF; > > strstart(filename, "file:", &filename); > > @@ -1247,6 +1248,16 @@ static int raw_create(const char *filename, QEMUOptionParameter *options, > while (options && options->name) { > if (!strcmp(options->name, BLOCK_OPT_SIZE)) { > total_size = options->value.n & BDRV_SECTOR_MASK; > + } else if (!strcmp(options->name, BLOCK_OPT_PREALLOC)) { > + if (!options->value.s || !strcmp(options->value.s, "off")) { > + prealloc = PREALLOC_MODE_OFF; > + } else if (!strcmp(options->value.s, "full")) { > + prealloc = PREALLOC_MODE_FULL; > + } else { > + error_setg(errp, "Invalid preallocation mode: '%s'", > + options->value.s); > + return -EINVAL; > + } > } > options++; > } > @@ -1256,16 +1267,27 @@ static int raw_create(const char *filename, QEMUOptionParameter *options, > if (fd < 0) { > result = -errno; > error_setg_errno(errp, -result, "Could not create file"); > - } else { > - if (ftruncate(fd, total_size) != 0) { > - result = -errno; > - error_setg_errno(errp, -result, "Could not resize file"); > - } > - if (qemu_close(fd) != 0) { > - result = -errno; > - error_setg_errno(errp, -result, "Could not close the new file"); > + goto out; > + } > + if (ftruncate(fd, total_size) != 0) { > + result = -errno; > + error_setg_errno(errp, -result, "Could not resize file"); > + goto out_close; > + } > + if (prealloc == PREALLOC_MODE_FULL) { > + /* posix_fallocate() doesn't set errno. */ > + result = -posix_fallocate(fd, 0, total_size); > + if (result != 0) { > + error_setg_errno(errp, -result, > + "Could not preallocate data for the new file"); > } Can you please make that PREALLOC_MODE_METADATA? You're really only preallocating metadata on a filesystem level here. If the backing block device were thin provisioned, we wouldn't make any attempt to preallocate that (e.g. with a loop writing zeroes or bdrv_write_zeroes() without BDRV_REQ_MAY_UNMAP), so I'd hardly call it "full" preallocation. Kevin