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[PATCH v4 1/2] libxcmd: generalize topology functions

To: xfs@xxxxxxxxxxx
Subject: [PATCH v4 1/2] libxcmd: generalize topology functions
From: "Bill O'Donnell" <billodo@xxxxxxxxxx>
Date: Fri, 12 Feb 2016 13:03:30 -0600
Delivered-to: xfs@xxxxxxxxxxx
In-reply-to: <1455303811-9874-1-git-send-email-billodo@xxxxxxxxxx>
References: <1455303811-9874-1-git-send-email-billodo@xxxxxxxxxx>
Move general topology functions from xfs_mkfs to new topology
collection in libxcmd.

Signed-off-by: Bill O'Donnell <billodo@xxxxxxxxxx>
---
 include/Makefile   |   1 +
 include/libxcmd.h  |  56 +++++++++
 libxcmd/Makefile   |   2 +-
 libxcmd/topology.c | 341 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 mkfs/Makefile      |   2 +-
 mkfs/xfs_mkfs.c    | 321 +------------------------------------------------
 6 files changed, 401 insertions(+), 322 deletions(-)
 create mode 100644 include/libxcmd.h
 create mode 100644 libxcmd/topology.c

diff --git a/include/Makefile b/include/Makefile
index 6148756..2671f07 100644
--- a/include/Makefile
+++ b/include/Makefile
@@ -20,6 +20,7 @@ include $(TOPDIR)/include/builddefs
 
 LIBHFILES = libxfs.h \
        libxlog.h \
+       libxcmd.h \
        atomic.h \
        bitops.h \
        cache.h \
diff --git a/include/libxcmd.h b/include/libxcmd.h
new file mode 100644
index 0000000..a912534
--- /dev/null
+++ b/include/libxcmd.h
@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2000-2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef __LIBXCMD_H__
+#define __LIBXCMD_H__
+
+#include "libxfs.h"
+#include <sys/time.h>
+
+/*
+ * Device topology information.
+ */
+typedef struct fs_topology {
+       int     dsunit;         /* stripe unit - data subvolume */
+       int     dswidth;        /* stripe width - data subvolume */
+       int     rtswidth;       /* stripe width - rt subvolume */
+       int     lsectorsize;    /* logical sector size &*/
+       int     psectorsize;    /* physical sector size */
+} fs_topology_t;
+
+extern void
+get_topology(
+       libxfs_init_t           *xi,
+       struct fs_topology      *ft,
+       int                     force_overwrite);
+
+extern void
+calc_default_ag_geometry(
+       int             blocklog,
+       __uint64_t      dblocks,
+       int             multidisk,
+       __uint64_t      *agsize,
+       __uint64_t      *agcount);
+
+extern int
+check_overwrite(
+       char            *device);
+
+
+
+#endif /* __LIBXCMD_H__ */
diff --git a/libxcmd/Makefile b/libxcmd/Makefile
index 7701ed9..aab8d6d 100644
--- a/libxcmd/Makefile
+++ b/libxcmd/Makefile
@@ -10,7 +10,7 @@ LT_CURRENT = 0
 LT_REVISION = 0
 LT_AGE = 0
 
-CFILES = command.c input.c paths.c projects.c help.c quit.c
+CFILES = command.c input.c paths.c projects.c help.c quit.c topology.c
 
 ifeq ($(HAVE_GETMNTENT),yes)
 LCFLAGS += -DHAVE_GETMNTENT
diff --git a/libxcmd/topology.c b/libxcmd/topology.c
new file mode 100644
index 0000000..4cbe4b1
--- /dev/null
+++ b/libxcmd/topology.c
@@ -0,0 +1,341 @@
+/*
+ * Copyright (c) 2000-2001,2005 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include "libxfs.h"
+#include "libxcmd.h"
+#ifdef ENABLE_BLKID
+#  include <blkid/blkid.h>
+#endif /* ENABLE_BLKID */
+#include "../mkfs/xfs_mkfs.h"
+
+#define TERABYTES(count, blog) ((__uint64_t)(count) << (40 - (blog)))
+#define GIGABYTES(count, blog) ((__uint64_t)(count) << (30 - (blog)))
+#define MEGABYTES(count, blog) ((__uint64_t)(count) << (20 - (blog)))
+
+void
+calc_default_ag_geometry(
+       int             blocklog,
+       __uint64_t      dblocks,
+       int             multidisk,
+       __uint64_t      *agsize,
+       __uint64_t      *agcount)
+{
+       __uint64_t      blocks = 0;
+       int             shift = 0;
+
+       /*
+        * First handle the high extreme - the point at which we will
+        * always use the maximum AG size.
+        *
+        * This applies regardless of storage configuration.
+        */
+       if (dblocks >= TERABYTES(32, blocklog)) {
+               blocks = XFS_AG_MAX_BLOCKS(blocklog);
+               goto done;
+       }
+
+       /*
+        * For the remainder we choose an AG size based on the
+        * number of data blocks available, trying to keep the
+        * number of AGs relatively small (especially compared
+        * to the original algorithm).  AG count is calculated
+        * based on the preferred AG size, not vice-versa - the
+        * count can be increased by growfs, so prefer to use
+        * smaller counts at mkfs time.
+        *
+        * For a single underlying storage device between 128MB
+        * and 4TB in size, just use 4 AGs, otherwise scale up
+        * smoothly between min/max AG sizes.
+        */
+
+       if (!multidisk && dblocks >= MEGABYTES(128, blocklog)) {
+               if (dblocks >= TERABYTES(4, blocklog)) {
+                       blocks = XFS_AG_MAX_BLOCKS(blocklog);
+                       goto done;
+               }
+               shift = 2;
+       } else if (dblocks > GIGABYTES(512, blocklog))
+               shift = 5;
+       else if (dblocks > GIGABYTES(8, blocklog))
+               shift = 4;
+       else if (dblocks >= MEGABYTES(128, blocklog))
+               shift = 3;
+       else if (dblocks >= MEGABYTES(64, blocklog))
+               shift = 2;
+       else if (dblocks >= MEGABYTES(32, blocklog))
+               shift = 1;
+       else
+               shift = 0;
+       /*
+        * If dblocks is not evenly divisible by the number of
+        * desired AGs, round "blocks" up so we don't lose the
+        * last bit of the filesystem. The same principle applies
+        * to the AG count, so we don't lose the last AG!
+        */
+       blocks = dblocks >> shift;
+       if (dblocks & xfs_mask32lo(shift)) {
+               if (blocks < XFS_AG_MAX_BLOCKS(blocklog))
+                   blocks++;
+       }
+done:
+       *agsize = blocks;
+       *agcount = dblocks / blocks + (dblocks % blocks != 0);
+}
+
+/*
+ * Check for existing filesystem or partition table on device.
+ * Returns:
+ *      1 for existing fs or partition
+ *      0 for nothing found
+ *     -1 for internal error
+ */
+#ifdef ENABLE_BLKID
+int
+check_overwrite(
+       char            *device)
+{
+       const char      *type;
+       blkid_probe     pr = NULL;
+       int             ret;
+       int             fd;
+       long long       size;
+       int             bsz;
+
+       if (!device || !*device)
+               return 0;
+
+       ret = -1; /* will reset on success of all setup calls */
+
+       fd = open(device, O_RDONLY);
+       if (fd < 0)
+               goto out;
+       platform_findsizes(device, fd, &size, &bsz);
+       close(fd);
+
+       /* nothing to overwrite on a 0-length device */
+       if (size == 0) {
+               ret = 0;
+               goto out;
+       }
+
+       pr = blkid_new_probe_from_filename(device);
+       if (!pr)
+               goto out;
+
+       ret = blkid_probe_enable_partitions(pr, 1);
+       if (ret < 0)
+               goto out;
+
+       ret = blkid_do_fullprobe(pr);
+       if (ret < 0)
+               goto out;
+
+       /*
+        * Blkid returns 1 for nothing found and 0 when it finds a signature,
+        * but we want the exact opposite, so reverse the return value here.
+        *
+        * In addition print some useful diagnostics about what actually is
+        * on the device.
+        */
+       if (ret) {
+               ret = 0;
+               goto out;
+       }
+
+       if (!blkid_probe_lookup_value(pr, "TYPE", &type, NULL)) {
+               fprintf(stderr,
+                       _("%s: %s appears to contain an existing "
+                       "filesystem (%s).\n"), progname, device, type);
+       } else if (!blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL)) {
+               fprintf(stderr,
+                       _("%s: %s appears to contain a partition "
+                       "table (%s).\n"), progname, device, type);
+       } else {
+               fprintf(stderr,
+                       _("%s: %s appears to contain something weird "
+                       "according to blkid\n"), progname, device);
+       }
+       ret = 1;
+
+out:
+       if (pr)
+               blkid_free_probe(pr);
+       if (ret == -1)
+               fprintf(stderr,
+                       _("%s: probe of %s failed, cannot detect "
+                         "existing filesystem.\n"), progname, device);
+       return ret;
+}
+
+static void
+blkid_get_topology(
+       const char      *device,
+       int             *sunit,
+       int             *swidth,
+       int             *lsectorsize,
+       int             *psectorsize,
+       int             force_overwrite)
+{
+
+       blkid_topology  tp;
+       blkid_probe     pr;
+       unsigned long   val;
+       struct stat     statbuf;
+
+       /* can't get topology info from a file */
+       if (!stat(device, &statbuf) && S_ISREG(statbuf.st_mode))
+               return;
+
+       pr = blkid_new_probe_from_filename(device);
+       if (!pr)
+               return;
+
+       tp = blkid_probe_get_topology(pr);
+       if (!tp)
+               goto out_free_probe;
+
+       val = blkid_topology_get_logical_sector_size(tp);
+       *lsectorsize = val;
+       val = blkid_topology_get_physical_sector_size(tp);
+       *psectorsize = val;
+       val = blkid_topology_get_minimum_io_size(tp);
+       *sunit = val;
+       val = blkid_topology_get_optimal_io_size(tp);
+       *swidth = val;
+
+       /*
+        * If the reported values are the same as the physical sector size
+        * do not bother to report anything.  It will only cause warnings
+        * if people specify larger stripe units or widths manually.
+        */
+       if (*sunit == *psectorsize || *swidth == *psectorsize) {
+               *sunit = 0;
+               *swidth = 0;
+       }
+
+       /*
+        * Blkid reports the information in terms of bytes, but we want it in
+        * terms of 512 bytes blocks (only to convert it to bytes later..)
+        */
+       *sunit = *sunit >> 9;
+       *swidth = *swidth >> 9;
+
+       if (blkid_topology_get_alignment_offset(tp) != 0) {
+               fprintf(stderr,
+                       _("warning: device is not properly aligned %s\n"),
+                       device);
+
+               if (!force_overwrite) {
+                       fprintf(stderr,
+                               _("Use -f to force usage of a misaligned 
device\n"));
+
+                       exit(EXIT_FAILURE);
+               }
+               /* Do not use physical sector size if the device is misaligned 
*/
+               *psectorsize = *lsectorsize;
+       }
+
+       blkid_free_probe(pr);
+       return;
+
+out_free_probe:
+       blkid_free_probe(pr);
+       fprintf(stderr,
+               _("warning: unable to probe device topology for device %s\n"),
+               device);
+}
+#else /* ifdef ENABLE_BLKID */
+/*
+ * Without blkid, we can't do a good check for signatures.
+ * So instead of some messy attempts, just disable any checks
+ * and always return 'nothing found'.
+ */
+#  warning BLKID is disabled, so signature detection and block device\
+ access are not working!
+
+int
+check_overwrite(
+       char            *device)
+{
+       return 1;
+}
+
+static void
+blkid_get_topology(
+       const char      *device,
+       int             *sunit,
+       int             *swidth,
+       int             *lsectorsize,
+       int             *psectorsize,
+       int             force_overwrite)
+{
+       /*
+        * Shouldn't make any difference (no blkid = no block device access),
+        * but make sure this dummy replacement returns with at least some
+        * sanity.
+        */
+       *lsectorsize = *psectorsize = 512;
+}
+
+#endif /* ENABLE_BLKID */
+
+
+void
+get_topology(
+       libxfs_init_t           *xi,
+       struct fs_topology      *ft,
+       int                     force_overwrite)
+{
+       struct stat statbuf;
+       char *dfile = xi->volname ? xi->volname : xi->dname;
+
+       /*
+        * If our target is a regular file, use platform_findsizes
+        * to try to obtain the underlying filesystem's requirements
+        * for direct IO; we'll set our sector size to that if possible.
+        */
+       if (xi->disfile ||
+           (!stat(dfile, &statbuf) && S_ISREG(statbuf.st_mode))) {
+               int fd;
+               int flags = O_RDONLY;
+               long long dummy;
+
+               /* with xi->disfile we may not have the file yet! */
+               if (xi->disfile)
+                       flags |= O_CREAT;
+
+               fd = open(dfile, flags, 0666);
+               if (fd >= 0) {
+                       platform_findsizes(dfile, fd, &dummy, &ft->lsectorsize);
+                       close(fd);
+                       ft->psectorsize = ft->lsectorsize;
+               } else
+                       ft->psectorsize = ft->lsectorsize = BBSIZE;
+       } else {
+               blkid_get_topology(dfile, &ft->dsunit, &ft->dswidth,
+                                  &ft->lsectorsize, &ft->psectorsize,
+                                  force_overwrite);
+       }
+
+       if (xi->rtname && !xi->risfile) {
+               int sunit, lsectorsize, psectorsize;
+
+               blkid_get_topology(xi->rtname, &sunit, &ft->rtswidth,
+                                  &lsectorsize, &psectorsize, force_overwrite);
+       }
+}
diff --git a/mkfs/Makefile b/mkfs/Makefile
index 570ab07..2997398 100644
--- a/mkfs/Makefile
+++ b/mkfs/Makefile
@@ -10,7 +10,7 @@ LTCOMMAND = mkfs.xfs
 HFILES = xfs_mkfs.h
 CFILES = maxtrres.c proto.c xfs_mkfs.c
 
-LLDLIBS += $(LIBBLKID) $(LIBXFS) $(LIBUUID) $(LIBRT) $(LIBPTHREAD)
+LLDLIBS += $(LIBBLKID) $(LIBXFS) $(LIBUUID) $(LIBRT) $(LIBPTHREAD) $(LIBXCMD)
 LTDEPENDENCIES += $(LIBXFS)
 LLDFLAGS = -static-libtool-libs
 
diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 4c3a802..0a02719 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -22,17 +22,7 @@
 #  include <blkid/blkid.h>
 #endif /* ENABLE_BLKID */
 #include "xfs_mkfs.h"
-
-/*
- * Device topology information.
- */
-struct fs_topology {
-       int     dsunit;         /* stripe unit - data subvolume */
-       int     dswidth;        /* stripe width - data subvolume */
-       int     rtswidth;       /* stripe width - rt subvolume */
-       int     lsectorsize;    /* logical sector size &*/
-       int     psectorsize;    /* physical sector size */
-};
+#include "libxcmd.h"
 
 /*
  * Prototypes for internal functions.
@@ -295,244 +285,6 @@ calc_stripe_factors(
        }
 }
 
-/*
- * Check for existing filesystem or partition table on device.
- * Returns:
- *      1 for existing fs or partition
- *      0 for nothing found
- *     -1 for internal error
- */
-#ifdef ENABLE_BLKID
-static int
-check_overwrite(
-       char            *device)
-{
-       const char      *type;
-       blkid_probe     pr = NULL;
-       int             ret;
-       int             fd;
-       long long       size;
-       int             bsz;
-
-       if (!device || !*device)
-               return 0;
-
-       ret = -1; /* will reset on success of all setup calls */
-
-       fd = open(device, O_RDONLY);
-       if (fd < 0)
-               goto out;
-       platform_findsizes(device, fd, &size, &bsz);
-       close(fd);
-
-       /* nothing to overwrite on a 0-length device */
-       if (size == 0) {
-               ret = 0;
-               goto out;
-       }
-
-       pr = blkid_new_probe_from_filename(device);
-       if (!pr)
-               goto out;
-
-       ret = blkid_probe_enable_partitions(pr, 1);
-       if (ret < 0)
-               goto out;
-
-       ret = blkid_do_fullprobe(pr);
-       if (ret < 0)
-               goto out;
-
-       /*
-        * Blkid returns 1 for nothing found and 0 when it finds a signature,
-        * but we want the exact opposite, so reverse the return value here.
-        *
-        * In addition print some useful diagnostics about what actually is
-        * on the device.
-        */
-       if (ret) {
-               ret = 0;
-               goto out;
-       }
-
-       if (!blkid_probe_lookup_value(pr, "TYPE", &type, NULL)) {
-               fprintf(stderr,
-                       _("%s: %s appears to contain an existing "
-                       "filesystem (%s).\n"), progname, device, type);
-       } else if (!blkid_probe_lookup_value(pr, "PTTYPE", &type, NULL)) {
-               fprintf(stderr,
-                       _("%s: %s appears to contain a partition "
-                       "table (%s).\n"), progname, device, type);
-       } else {
-               fprintf(stderr,
-                       _("%s: %s appears to contain something weird "
-                       "according to blkid\n"), progname, device);
-       }
-       ret = 1;
-
-out:
-       if (pr)
-               blkid_free_probe(pr);
-       if (ret == -1)
-               fprintf(stderr,
-                       _("%s: probe of %s failed, cannot detect "
-                         "existing filesystem.\n"), progname, device);
-       return ret;
-}
-
-static void blkid_get_topology(
-       const char      *device,
-       int             *sunit,
-       int             *swidth,
-       int             *lsectorsize,
-       int             *psectorsize,
-       int             force_overwrite)
-{
-
-       blkid_topology tp;
-       blkid_probe pr;
-       unsigned long val;
-       struct stat statbuf;
-
-       /* can't get topology info from a file */
-       if (!stat(device, &statbuf) && S_ISREG(statbuf.st_mode))
-               return;
-
-       pr = blkid_new_probe_from_filename(device);
-       if (!pr)
-               return;
-
-       tp = blkid_probe_get_topology(pr);
-       if (!tp)
-               goto out_free_probe;
-
-       val = blkid_topology_get_logical_sector_size(tp);
-       *lsectorsize = val;
-       val = blkid_topology_get_physical_sector_size(tp);
-       *psectorsize = val;
-       val = blkid_topology_get_minimum_io_size(tp);
-       *sunit = val;
-       val = blkid_topology_get_optimal_io_size(tp);
-       *swidth = val;
-
-       /*
-        * If the reported values are the same as the physical sector size
-        * do not bother to report anything.  It will only cause warnings
-        * if people specify larger stripe units or widths manually.
-        */
-       if (*sunit == *psectorsize || *swidth == *psectorsize) {
-               *sunit = 0;
-               *swidth = 0;
-       }
-
-       /*
-        * Blkid reports the information in terms of bytes, but we want it in
-        * terms of 512 bytes blocks (only to convert it to bytes later..)
-        */
-       *sunit = *sunit >> 9;
-       *swidth = *swidth >> 9;
-
-       if (blkid_topology_get_alignment_offset(tp) != 0) {
-               fprintf(stderr,
-                       _("warning: device is not properly aligned %s\n"),
-                       device);
-
-               if (!force_overwrite) {
-                       fprintf(stderr,
-                               _("Use -f to force usage of a misaligned 
device\n"));
-
-                       exit(EXIT_FAILURE);
-               }
-               /* Do not use physical sector size if the device is misaligned 
*/
-               *psectorsize = *lsectorsize;
-       }
-
-       blkid_free_probe(pr);
-       return;
-
-out_free_probe:
-       blkid_free_probe(pr);
-       fprintf(stderr,
-               _("warning: unable to probe device topology for device %s\n"),
-               device);
-}
-#else /* ifdef ENABLE_BLKID */
-/*
- * Without blkid, we can't do a good check for signatures.
- * So instead of some messy attempts, just disable any checks
- * and always return 'nothing found'.
- */
-#  warning BLKID is disabled, so signature detection and block device\
- access are not working!
-static int
-check_overwrite(
-       char            *device)
-{
-       return 1;
-}
-
-static void blkid_get_topology(
-       const char      *device,
-       int             *sunit,
-       int             *swidth,
-       int             *lsectorsize,
-       int             *psectorsize,
-       int             force_overwrite)
-{
-       /*
-        * Shouldn't make any difference (no blkid = no block device access),
-        * but make sure this dummy replacement returns with at least some
-        * sanity.
-        */
-       *lsectorsize = *psectorsize = 512;
-}
-
-#endif /* ENABLE_BLKID */
-
-static void get_topology(
-       libxfs_init_t           *xi,
-       struct fs_topology      *ft,
-       int                     force_overwrite)
-{
-       struct stat statbuf;
-       char *dfile = xi->volname ? xi->volname : xi->dname;
-
-       /*
-        * If our target is a regular file, use platform_findsizes
-        * to try to obtain the underlying filesystem's requirements
-        * for direct IO; we'll set our sector size to that if possible.
-        */
-       if (xi->disfile ||
-           (!stat(dfile, &statbuf) && S_ISREG(statbuf.st_mode))) {
-               int fd;
-               int flags = O_RDONLY;
-               long long dummy;
-
-               /* with xi->disfile we may not have the file yet! */
-               if (xi->disfile)
-                       flags |= O_CREAT;
-
-               fd = open(dfile, flags, 0666);
-               if (fd >= 0) {
-                       platform_findsizes(dfile, fd, &dummy, &ft->lsectorsize);
-                       close(fd);
-                       ft->psectorsize = ft->lsectorsize;
-               } else
-                       ft->psectorsize = ft->lsectorsize = BBSIZE;
-       } else {
-               blkid_get_topology(dfile, &ft->dsunit, &ft->dswidth,
-                                  &ft->lsectorsize, &ft->psectorsize,
-                                  force_overwrite);
-       }
-
-       if (xi->rtname && !xi->risfile) {
-               int sunit, lsectorsize, psectorsize;
-
-               blkid_get_topology(xi->rtname, &sunit, &ft->rtswidth,
-                                  &lsectorsize, &psectorsize, force_overwrite);
-       }
-}
-
 static void
 fixup_log_stripe_unit(
        int             lsflag,
@@ -640,77 +392,6 @@ calc_default_imaxpct(
        return 1;
 }
 
-
-void
-calc_default_ag_geometry(
-       int             blocklog,
-       __uint64_t      dblocks,
-       int             multidisk,
-       __uint64_t      *agsize,
-       __uint64_t      *agcount)
-{
-       __uint64_t      blocks = 0;
-       int             shift = 0;
-
-       /*
-        * First handle the high extreme - the point at which we will
-        * always use the maximum AG size.
-        *
-        * This applies regardless of storage configuration.
-        */
-       if (dblocks >= TERABYTES(32, blocklog)) {
-               blocks = XFS_AG_MAX_BLOCKS(blocklog);
-               goto done;
-       }
-
-       /*
-        * For the remainder we choose an AG size based on the
-        * number of data blocks available, trying to keep the
-        * number of AGs relatively small (especially compared
-        * to the original algorithm).  AG count is calculated
-        * based on the preferred AG size, not vice-versa - the
-        * count can be increased by growfs, so prefer to use
-        * smaller counts at mkfs time.
-        *
-        * For a single underlying storage device between 128MB
-        * and 4TB in size, just use 4 AGs, otherwise scale up
-        * smoothly between min/max AG sizes.
-        */
-
-       if (!multidisk && dblocks >= MEGABYTES(128, blocklog)) {
-               if (dblocks >= TERABYTES(4, blocklog)) {
-                       blocks = XFS_AG_MAX_BLOCKS(blocklog);
-                       goto done;
-               }
-               shift = 2;
-       } else if (dblocks > GIGABYTES(512, blocklog))
-               shift = 5;
-       else if (dblocks > GIGABYTES(8, blocklog))
-               shift = 4;
-       else if (dblocks >= MEGABYTES(128, blocklog))
-               shift = 3;
-       else if (dblocks >= MEGABYTES(64, blocklog))
-               shift = 2;
-       else if (dblocks >= MEGABYTES(32, blocklog))
-               shift = 1;
-       else
-               shift = 0;
-       /*
-        * If dblocks is not evenly divisible by the number of
-        * desired AGs, round "blocks" up so we don't lose the
-        * last bit of the filesystem. The same principle applies
-        * to the AG count, so we don't lose the last AG!
-        */
-       blocks = dblocks >> shift;
-       if (dblocks & xfs_mask32lo(shift)) {
-               if (blocks < XFS_AG_MAX_BLOCKS(blocklog))
-                   blocks++;
-       }
-done:
-       *agsize = blocks;
-       *agcount = dblocks / blocks + (dblocks % blocks != 0);
-}
-
 static void
 validate_ag_geometry(
        int             blocklog,
-- 
2.5.0

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