Previously, xfs_info / xfs_growfs would only operate if
pointed at the root of a mounted xfs filesystem, and not a
file within that filesystem. (Although the ioctl will allow it,
the utility does not, to avoid errors and confusion).
When the info capability was moved to xfs_spaceman, this restriction
got lost.
And now that xfs_db can print xfs_info-like info about image files
and devices, the potential exists for misdirecting the request
and running the ioctl on a file and getting the underlying fs
info, rather than using libxfs to parse the image itself, if
the wrong tool is used to point at the file.
Add a new function to (ab)use XFS_IOC_FSINUMBERS to determine
whether the thing we've been pointed at is in fact the root
directory of a mounted xfs filesystem. If not, don't proceed.
Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
---
I need to look, perhaps this could simplify growfs as well.
I'm not sure I've put this in the right place (libfrog?) either,
but for the sake of discsussion ...
diff --git a/include/libfrog.h b/include/libfrog.h
index 2d8055b..f7cd00a 100644
--- a/include/libfrog.h
+++ b/include/libfrog.h
@@ -18,6 +18,9 @@
#ifndef __LIBFROG_UTIL_H_
#define __LIBFROG_UTIL_H_
+#include <stdbool.h>
+
unsigned int log2_roundup(unsigned int i);
+bool fd_is_xfs_root(int fd);
#endif /* __LIBFROG_UTIL_H_ */
diff --git a/libfrog/util.c b/libfrog/util.c
index 4896e4b..4913f38 100644
--- a/libfrog/util.c
+++ b/libfrog/util.c
@@ -16,6 +16,7 @@
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "platform_defs.h"
+#include "libxfs.h"
#include "libfrog.h"
/*
@@ -34,3 +35,44 @@ log2_roundup(unsigned int i)
}
return rval;
}
+
+/* Test whether a given fd is the root of a mounted xfs filesystem */
+bool
+fd_is_xfs_root(
+ int fd)
+{
+ struct xfs_fsop_bulkreq igrpreq = {0};
+ struct xfs_inogrp inogrp;
+ __u64 igrp_ino = 0;
+ __s32 igrplen = 0;
+ __u64 first_ino;
+ struct stat statbuf;
+
+ igrpreq.lastip = &igrp_ino;
+ igrpreq.icount = 1;
+ igrpreq.ubuffer = &inogrp;
+ igrpreq.ocount = &igrplen;
+
+ if (ioctl(fd, XFS_IOC_FSINUMBERS, &igrpreq))
+ return false;
+
+ /* find the first allocated inode */
+ while (!ioctl(fd, XFS_IOC_FSINUMBERS, &igrpreq)) {
+ if (inogrp.xi_alloccount)
+ break;
+ }
+
+ /* The ioctl failed ... */
+ if (!inogrp.xi_alloccount)
+ return false;
+
+ first_ino = inogrp.xi_startino + libxfs_lowbit64(inogrp.xi_allocmask);
+
+ if (fstat(fd, &statbuf))
+ return false;
+
+ if (first_ino != statbuf.st_ino)
+ return false;
+
+ return true;
+}
diff --git a/libxfs/libxfs_api_defs.h b/libxfs/libxfs_api_defs.h
index a23a28d..79a0bd7 100644
--- a/libxfs/libxfs_api_defs.h
+++ b/libxfs/libxfs_api_defs.h
@@ -25,6 +25,8 @@
* it can be included in both the internal and external libxfs header files
* without introducing any depenencies between the two.
*/
+#define xfs_lowbit32 libxfs_lowbit32
+#define xfs_lowbit64 libxfs_lowbit64
#define xfs_highbit32 libxfs_highbit32
#define xfs_highbit64 libxfs_highbit64
diff --git a/spaceman/info.c b/spaceman/info.c
index 6557b54..df088f4 100644
--- a/spaceman/info.c
+++ b/spaceman/info.c
@@ -44,6 +44,13 @@ info_f(
struct xfs_fsop_geom geo;
int error;
+ if (!fd_is_xfs_root(file->fd)) {
+ fprintf(stderr, _("%s: %s is not a mounted XFS filesystem\n"),
+ progname, file->name);
+ exitcode = 1;
+ return 0;
+ }
+
/* get the current filesystem size & geometry */
error = ioctl(file->fd, XFS_IOC_FSGEOMETRY, &geo);
if (error) {
--
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