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 <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
