To check whether a file system is mounted, nilfs-tune was comparing
the device name to the contents of /etc/mtab. This check does not
detect a mounted file system when the device has multiple names, which
is a common case when using LVM. (LVM creates symbolic links from
/dev/mapper/vg-lv to /dev/dm-X.)
This patch, borrowed from the analogous check in e2fsprogs, compares
the device number (field st_rdev of struct stat) rather than the
device name.
Signed-off-by: Matteo Frigo <athena@xxxxxxxx>
---
configure.ac | 3 +-
sbin/nilfs-tune/nilfs-tune.c | 69 +++++++++++++++++++++++++++++++----------
2 files changed, 54 insertions(+), 18 deletions(-)
diff --git a/configure.ac b/configure.ac
index af75142..963e2fd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -37,7 +37,8 @@ AC_HEADER_STDC
AC_HEADER_SYS_WAIT
AC_CHECK_HEADERS([fcntl.h libintl.h limits.h locale.h mntent.h paths.h \
stdlib.h string.h strings.h sys/ioctl.h sys/mount.h \
- sys/time.h syslog.h unistd.h linux/types.h grp.h pwd.h])
+ sys/time.h syslog.h unistd.h linux/types.h grp.h pwd.h \
+ mntent.h])
# Checks for typedefs, structures, and compiler characteristics.
AC_C_CONST
diff --git a/sbin/nilfs-tune/nilfs-tune.c b/sbin/nilfs-tune/nilfs-tune.c
index 18513f2..5b7f030 100644
--- a/sbin/nilfs-tune/nilfs-tune.c
+++ b/sbin/nilfs-tune/nilfs-tune.c
@@ -58,6 +58,11 @@
#include <pwd.h>
#endif /* HAVE_PWD_H */
+#ifdef HAVE_MNTENT_H
+#include <mntent.h>
+#endif
+
+#include <sys/stat.h>
#include <ctype.h>
#include <errno.h>
@@ -444,26 +449,57 @@ int modify_nilfs(char *device, struct nilfs_tune_options *opts)
return ret;
}
-/* Code borrowed from nilfs2-util/sbin/mkfs/mkfs.c */
+/* check_mount() checks whether DEVICE is a mounted file system.
+ Returns 0 if the DEVICE is *not* mounted (which we consider a
+ successful outcome), and -1 if DEVICE is mounted or if the mount
+ status cannot be determined.
+
+ Derived from e2fsprogs/lib/ext2fs/ismounted.c
+ Copyright (C) 1995,1996,1997,1998,1999,2000 Theodore Ts'o,
+ LGPL v2
+*/
static int check_mount(const char *device)
{
- FILE *fp;
- char line[LINE_BUFFER_SIZE];
-
- fp = fopen(MOUNTS, "r");
- if (fp == NULL) {
+ struct mntent *mnt;
+ struct stat st_buf;
+ FILE *f;
+ dev_t file_dev = 0, file_rdev = 0;
+ ino_t file_ino = 0;
+
+ f = setmntent(MOUNTS, "r");
+ if (f == NULL) {
fprintf(stderr, "Error: cannot open %s!", MOUNTS);
- return 1;
+ return -1;
}
- while (fgets(line, LINE_BUFFER_SIZE, fp) != NULL) {
- if (strncmp(strtok(line, " "), device, strlen(device)) == 0) {
- fclose(fp);
- return 1;
+ if (stat(device, &st_buf) == 0) {
+ if (S_ISBLK(st_buf.st_mode)) {
+ file_rdev = st_buf.st_rdev;
+ } else {
+ file_dev = st_buf.st_dev;
+ file_ino = st_buf.st_ino;
}
}
- fclose(fp);
- return 0;
+
+ while ((mnt = getmntent(f)) != NULL) {
+ if (mnt->mnt_fsname[0] != '/')
+ continue;
+ if (strcmp(device, mnt->mnt_fsname) == 0)
+ break;
+ if (stat(mnt->mnt_fsname, &st_buf) == 0) {
+ if (S_ISBLK(st_buf.st_mode)) {
+ if (file_rdev && (file_rdev == st_buf.st_rdev))
+ break;
+ } else {
+ if (file_dev && ((file_dev == st_buf.st_dev) &&
+ (file_ino == st_buf.st_ino)))
+ break;
+ }
+ }
+ }
+
+ endmntent(f);
+ return (mnt == NULL) ? 0 : -1;
}
int main(int argc, char *argv[])
@@ -486,12 +522,11 @@ int main(int argc, char *argv[])
exit(EXIT_FAILURE);
}
- if (!opts.force && opts.flags == O_RDWR && check_mount(device)) {
- fprintf(stderr, "Warning: %s is currently mounted.\n"
+ if (!opts.force && opts.flags == O_RDWR && (check_mount(device) < 0)) {
+ fprintf(stderr, "ERROR: %s is currently mounted. Aborting execution.\n"
"Running nilfs-tune on a mounted file system "
"may cause SEVERE damage.\n"
- "You can force to modify file system by "
- "\"-f\" option.\n",
+ "You can use the \"-f\" option to force this operation.\n",
device);
exit(EXIT_SUCCESS);
}
--
1.7.1
--
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