From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 7B9357CBF for ; Sun, 13 Dec 2015 19:27:29 -0600 (CST) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay3.corp.sgi.com (Postfix) with ESMTP id F3C06AC005 for ; Sun, 13 Dec 2015 17:27:28 -0800 (PST) Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id 5LFJGoaBpjBErm0g for ; Sun, 13 Dec 2015 17:27:26 -0800 (PST) Date: Mon, 14 Dec 2015 12:27:12 +1100 From: Dave Chinner Subject: Re: [PATCH, RFC] mkfs: get sector size from host fs dev when mkfs'ing file Message-ID: <20151214012712.GL26718@dastard> References: <5660CD5E.2040209@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <5660CD5E.2040209@redhat.com> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Eric Sandeen Cc: xfs@oss.sgi.com On Thu, Dec 03, 2015 at 05:16:46PM -0600, Eric Sandeen wrote: > Now that we allow logical-sector-sized DIOs even if our xfs > filesystem is set to physical-sector-sized "sectors," we can > allow the creation of filesystem images with block and sector > sizes down to the host device's logical sector size, rather > than the filesystem's sector size. > > So in platform_findsizes(), change our query of the filesystem > to a query of the device, and use that for sector size in the > S_IFREG case. > > This allows the creation of i.e. a 2k block sized image on > an xfs filesystem w/ 4k sector size created on a 4k/512 > block device, which would otherwise fail today. > > Signed-off-by: Eric Sandeen > --- > > This feels like about my 5th stab at this; it seems like > the correct thing to do but by now my brain is full. > Seem sane? I'm not sure I like the idea of encoding blkid functionality into libxfs, especially as blkid support is optional: commit 6635d6ab510c58996f5ed3f212148db5e3c299ba Author: Jan Tulak Date: Wed Oct 14 10:57:39 2015 +1100 build: make libblkid usage optional > Still needs a run through xfstests but wanted to see if this > was obviously bonkers or not...? > > (I don't know why copy/Makefile needs a $(LIBBLKID), either...) Because libxfs now has a dependency on libblkid, and libxfs is a static library so it doesn't resolve undefined extern objects as the library is built. That is only done when linking binaries.... > index 885016a..3a8dc12 100644 > --- a/libxfs/linux.c > +++ b/libxfs/linux.c > @@ -24,6 +24,7 @@ > #include > #include > #include > +#include > > #include "libxfs_priv.h" > #include "xfs_fs.h" > @@ -142,18 +143,29 @@ platform_findsizes(char *path, int fd, long long *sz, int *bsz) > progname, path, strerror(errno)); > exit(1); > } > + > if ((st.st_mode & S_IFMT) == S_IFREG) { > - struct xfs_fsop_geom_v1 geom = { 0 }; > + int fd; > + char *hostfs_dev_path; /* path to host fs device */ > > *sz = (long long)(st.st_size >> 9); > - if (ioctl(fd, XFS_IOC_FSGEOMETRY_V1, &geom) < 0) { > - /* > - * fall back to BBSIZE; mkfs might fail if there's a > - * size mismatch between the image & the host fs... > - */ > - *bsz = BBSIZE; > - } else > - *bsz = geom.sectsize; > + > + /* > + * Default to BBSIZE; mkfs might fail if there's a > + * size mismatch between the image & the host fs... > + */ > + *bsz = BBSIZE; > + > + /* Get logical sector size of host device */ > + hostfs_dev_path = blkid_devno_to_devname(st.st_dev); > + if (hostfs_dev_path) { > + fd = open(hostfs_dev_path, O_RDONLY); > + if (fd >= 0) > + if (ioctl(fd, BLKSSZGET, bsz) < 0) > + *bsz = BBSIZE; > + close(fd); > + free(hostfs_dev_path); > + } So the current behaviour is to use the underlying filesystem sector size, but we might have a 4k fs sector on a 512 physical sector device, and you want to detect this, right? The logical sector size is exposed by the filesystem in the XFS_IOC_DIOINFO information. i.e: case XFS_IOC_DIOINFO: { struct dioattr da; xfs_buftarg_t *target = XFS_IS_REALTIME_INODE(ip) ? mp->m_rtdev_targp : mp->m_ddev_targp; da.d_mem = da.d_miniosz = target->bt_logical_sectorsize; da.d_maxiosz = INT_MAX & ~(da.d_miniosz - 1); if (copy_to_user(arg, &da, sizeof(da))) return -EFAULT; return 0; } Isn't this exactly what XFS_IOC_DIOINFO is for? (Oh, and "old kernels don't support...." simply means the distros will have a kernel patch to backport, too....) Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs