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umount: instead of non-standard -D, use -d with opposite meaning

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(closes bug 1604)
umount: do not try to free loop device or erase mtab if remounted ro
umount: do not complain several times about the same mountpoint

function                                             old     new   delta
umount_main                                          646     638      -8
packed_usage                                       23662   23652     -10
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-18)             Total: -18 bytes
This commit is contained in:
Denis Vlasenko 2008-02-14 12:00:21 +00:00
parent 773f6710c1
commit b2e578a1f2
2 changed files with 38 additions and 37 deletions
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2
include/usage.h
View File

@ -3996,7 +3996,7 @@ USE_FEATURE_RUN_PARTS_FANCY("\n -l Prints names of all matching files even when
"\n -l Lazy umount (detach filesystem)" \
"\n -f Force umount (i.e., unreachable NFS server)" \
USE_FEATURE_MOUNT_LOOP( \
"\n -D Do not free loop device (if a loop device has been used)")
"\n -d Free loop device if it has been used")
#define umount_example_usage \
"$ umount /dev/hdc1\n"

73
util-linux/umount.c
View File

@ -13,14 +13,19 @@
#include "libbb.h"
/* ignored: -v -d -t -i */
#define OPTION_STRING "flDnra" "vdt:i"
#define OPTION_STRING "fldnra" "vdt:i"
#define OPT_FORCE (1 << 0)
#define OPT_LAZY (1 << 1)
#define OPT_DONTFREELOOP (1 << 2)
#define OPT_FREELOOP (1 << 2)
#define OPT_NO_MTAB (1 << 3)
#define OPT_REMOUNT (1 << 4)
#define OPT_ALL (ENABLE_FEATURE_UMOUNT_ALL ? (1 << 5) : 0)
// These constants from linux/fs.h must match OPT_FORCE and OPT_LAZY,
// otherwise "doForce" trick below won't work!
//#define MNT_FORCE 0x00000001 /* Attempt to forcibly umount */
//#define MNT_DETACH 0x00000002 /* Just detach from the tree */
int umount_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int umount_main(int argc, char **argv)
{
@ -28,7 +33,7 @@ int umount_main(int argc, char **argv)
char *const path = xmalloc(PATH_MAX + 2); /* to save stack */
struct mntent me;
FILE *fp;
char *fstype = 0;
char *fstype = NULL;
int status = EXIT_SUCCESS;
unsigned opt;
struct mtab_list {
@ -37,13 +42,9 @@ int umount_main(int argc, char **argv)
struct mtab_list *next;
} *mtl, *m;
/* Parse any options */
opt = getopt32(argv, OPTION_STRING, &fstype);
argc -= optind;
//argc -= optind;
argv += optind;
doForce = MAX((opt & OPT_FORCE), (opt & OPT_LAZY));
/* Get a list of mount points from mtab. We read them all in now mostly
@ -51,12 +52,10 @@ int umount_main(int argc, char **argv)
* we iterate over it, or about getting stuck in a loop on the same failing
* entry. Notice that this also naturally reverses the list so that -a
* umounts the most recent entries first. */
m = mtl = NULL;
m = mtl = 0;
/* If we're umounting all, then m points to the start of the list and
* the argument list should be empty (which will match all). */
// If we're umounting all, then m points to the start of the list and
// the argument list should be empty (which will match all).
fp = setmntent(bb_path_mtab_file, "r");
if (!fp) {
if (opt & OPT_ALL)
@ -75,11 +74,11 @@ int umount_main(int argc, char **argv)
endmntent(fp);
}
/* If we're not umounting all, we need at least one argument. */
// If we're not umounting all, we need at least one argument.
if (!(opt & OPT_ALL) && !fstype) {
m = 0;
if (!argc)
if (!argv[0])
bb_show_usage();
m = NULL;
}
// Loop through everything we're supposed to umount, and do so.
@ -93,10 +92,10 @@ int umount_main(int argc, char **argv)
// For umount -a, end of mtab means time to exit.
else if (opt & OPT_ALL)
break;
// Get next command line argument (and look it up in mtab list)
else if (!argc--)
break;
// Use command line argument (and look it up in mtab list)
else {
if (!zapit)
break;
argv++;
realpath(zapit, path);
for (m = mtl; m; m = m->next)
@ -112,26 +111,29 @@ int umount_main(int argc, char **argv)
curstat = umount(zapit);
// Force the unmount, if necessary.
if (curstat && doForce) {
if (curstat && doForce)
curstat = umount2(zapit, doForce);
if (curstat)
bb_error_msg("forced umount of %s failed!", zapit);
}
// If still can't umount, maybe remount read-only?
if (curstat && (opt & OPT_REMOUNT) && errno == EBUSY && m) {
curstat = mount(m->device, zapit, NULL, MS_REMOUNT|MS_RDONLY, NULL);
bb_error_msg(curstat ? "cannot remount %s read-only" :
"%s busy - remounted read-only", m->device);
}
if (curstat) {
status = EXIT_FAILURE;
bb_perror_msg("cannot umount %s", zapit);
if ((opt & OPT_REMOUNT) && errno == EBUSY && m) {
// Note! Even if we succeed here, later we should not
// free loop device or erase mtab entry!
const char *msg = "%s busy - remounted read-only";
curstat = mount(m->device, zapit, NULL, MS_REMOUNT|MS_RDONLY, NULL);
if (curstat) {
msg = "cannot remount %s read-only";
status = EXIT_FAILURE;
}
bb_error_msg(msg, m->device);
} else {
status = EXIT_FAILURE;
bb_perror_msg("cannot %sumount %s", (doForce ? "forcibly " : ""), zapit);
}
} else {
/* De-allocate the loop device. This ioctl should be ignored on
* any non-loop block devices. */
if (ENABLE_FEATURE_MOUNT_LOOP && !(opt & OPT_DONTFREELOOP) && m)
// De-allocate the loop device. This ioctl should be ignored on
// any non-loop block devices.
if (ENABLE_FEATURE_MOUNT_LOOP && (opt & OPT_FREELOOP) && m)
del_loop(m->device);
if (ENABLE_FEATURE_MTAB_SUPPORT && !(opt & OPT_NO_MTAB) && m)
erase_mtab(m->dir);
@ -140,13 +142,12 @@ int umount_main(int argc, char **argv)
// Find next matching mtab entry for -a or umount /dev
// Note this means that "umount /dev/blah" will unmount all instances
// of /dev/blah, not just the most recent.
while (m && (m = m->next))
if (m) while ((m = m->next) != NULL)
if ((opt & OPT_ALL) || !strcmp(path, m->device))
break;
}
// Free mtab list if necessary
if (ENABLE_FEATURE_CLEAN_UP) {
while (mtl) {
m = mtl->next;