[PATCH 2/2 V2] mkfs.xfs: don't call blkid_get_topology on regular files

[Eric Sandeen <sandeen@xxxxxxxxxxx>]

If we encounter a target that's really a regular file,
even without "-d file..." on the cmdline, call
platform_findsizes() instead of blkid_get_topology to
try to discover the "sector size" via the fsgeom() call.

Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
---

V2: Lose local "isa_file" flag, just switch based on 
(xi->disfile) or (stat works & S_ISREG)

diff --git a/mkfs/xfs_mkfs.c b/mkfs/xfs_mkfs.c
index 188b6b3..3b8bf67 100644
--- a/mkfs/xfs_mkfs.c
+++ b/mkfs/xfs_mkfs.c
@@ -456,9 +456,25 @@ static void get_topology(
        struct fs_topology      *ft,
        int                     force_overwrite)
 {
-       if (!xi->disfile) {
-               const char *dfile = xi->volname ? xi->volname : xi->dname;
+       struct stat statbuf;
+       char *dfile = xi->volname ? xi->volname : xi->dname;
 
+       /*
+        * Don't call blkid for topology if this is a "-d file" target, or
+        * if we've simply been pointed at a regular file.  platform_findsizes
+        * will attempt to find the underlying sector size of the host fs.
+        */
+       if (xi->disfile ||
+           (!stat(dfile, &statbuf) && S_ISREG(statbuf.st_mode))) {
+               int fd;
+               long long dummy;
+
+               fd = open(dfile, O_RDONLY);
+               if (fd >= 0) {
+                       platform_findsizes(dfile, fd, &dummy, &ft->lsectorsize);
+                       close(fd);
+               }
+       } else {
                blkid_get_topology(dfile, &ft->dsunit, &ft->dswidth,
                                   &ft->lsectorsize, &ft->psectorsize,
                                   force_overwrite);