autofs-5.1.9 - refactor amd function umount_amd_ext_mount()
From: Ian Kent <raven@themaw.net>
The amd mounts function umount_amd_ext_mount() needs some improvement.
Make sure the function returns true for success and false for failure
and add a parameter to control if the expternal mount reference should
be decremented on successful umount.
If the reference count of the external mount is greater than 1 there's
some other mount using (symlink pointing to) it so don't try to umount
it just return success.
Also check for the case where the mount is already mounted.
Signed-off-by: Ian Kent <raven@themaw.net>
---
CHANGELOG | 1 +
daemon/automount.c | 4 +--
include/mounts.h | 2 +
lib/mounts.c | 80 ++++++++++++++++++++++++++++++---------------------
modules/parse_amd.c | 10 +++---
5 files changed, 56 insertions(+), 41 deletions(-)
diff --git a/CHANGELOG b/CHANGELOG
index 07ed2478b..bc1511192 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -8,6 +8,7 @@
- fix amd external mount mount handling.
- don't free ext mount if mounted.
- refactor amd function do_program_mount().
+- refactor umount_amd_ext_mount().
02/11/2023 autofs-5.1.9
- fix kernel mount status notification.
diff --git a/daemon/automount.c b/daemon/automount.c
index 6cb3b1be4..474b29a16 100644
--- a/daemon/automount.c
+++ b/daemon/automount.c
@@ -633,7 +633,7 @@ static int umount_subtree_mounts(struct autofs_point *ap, const char *path, unsi
/* Check for an external mount and umount if possible */
mnt = mnts_find_amdmount(path);
if (mnt) {
- umount_amd_ext_mount(ap, mnt->ext_mp);
+ umount_amd_ext_mount(ap, mnt->ext_mp, 1);
mnts_remove_amdmount(path);
mnts_put_mount(mnt);
}
@@ -699,7 +699,7 @@ int umount_multi(struct autofs_point *ap, const char *path, int incl)
/* Check for an external mount and attempt umount if needed */
mnt = mnts_find_amdmount(path);
if (mnt) {
- umount_amd_ext_mount(ap, mnt->ext_mp);
+ umount_amd_ext_mount(ap, mnt->ext_mp, 1);
mnts_remove_amdmount(path);
mnts_put_mount(mnt);
}
diff --git a/include/mounts.h b/include/mounts.h
index 8e6f62a02..381d120c7 100644
--- a/include/mounts.h
+++ b/include/mounts.h
@@ -199,7 +199,7 @@ int try_remount(struct autofs_point *, struct mapent *, unsigned int);
void set_indirect_mount_tree_catatonic(struct autofs_point *);
void set_direct_mount_tree_catatonic(struct autofs_point *, struct mapent *);
int umount_ent(struct autofs_point *, const char *);
-int umount_amd_ext_mount(struct autofs_point *, const char *);
+int umount_amd_ext_mount(struct autofs_point *, const char *, int remove);
int clean_stale_multi_triggers(struct autofs_point *, struct mapent *, char *, const char *);
#endif
diff --git a/lib/mounts.c b/lib/mounts.c
index 9a12dbf2f..dda19a9ea 100644
--- a/lib/mounts.c
+++ b/lib/mounts.c
@@ -3078,37 +3078,62 @@ int umount_ent(struct autofs_point *ap, const char *path)
return mounted;
}
-int umount_amd_ext_mount(struct autofs_point *ap, const char *path)
+int umount_amd_ext_mount(struct autofs_point *ap, const char *path, int remove)
{
struct ext_mount *em;
char *umount = NULL;
- char *mp;
+ char *mp = NULL;
int rv = 1;
+ int ret;
pthread_mutex_lock(&ext_mount_hash_mutex);
-
em = ext_mount_lookup(path);
if (!em) {
pthread_mutex_unlock(&ext_mount_hash_mutex);
+ rv = 0;
goto out;
}
mp = strdup(em->mp);
if (!mp) {
pthread_mutex_unlock(&ext_mount_hash_mutex);
+ rv = 0;
goto out;
}
if (em->umount) {
umount = strdup(em->umount);
if (!umount) {
pthread_mutex_unlock(&ext_mount_hash_mutex);
- free(mp);
+ rv = 0;
goto out;
}
}
-
+ /* Don't try and umount if there's more than one
+ * user of the external mount.
+ */
+ if (em->ref > 1) {
+ pthread_mutex_unlock(&ext_mount_hash_mutex);
+ if (!remove)
+ error(ap->logopt,
+ "reference count mismatch, called with remove false");
+ else
+ ext_mount_remove(mp);
+ goto out;
+ }
+ /* This shouldn't happen ... */
+ if (!is_mounted(mp, MNTS_REAL)) {
+ pthread_mutex_unlock(&ext_mount_hash_mutex);
+ error(ap->logopt, "failed to umount program mount at %s", mp);
+ if (remove)
+ ext_mount_remove(mp);
+ goto out;
+ }
pthread_mutex_unlock(&ext_mount_hash_mutex);
- if (umount) {
+ if (!umount) {
+ ret = umount_ent(ap, mp);
+ if (ret)
+ rv = 0;
+ } else {
char *prog;
char **argv;
int argc = -1;
@@ -3117,41 +3142,30 @@ int umount_amd_ext_mount(struct autofs_point *ap, const char *path)
argv = NULL;
argc = construct_argv(umount, &prog, &argv);
- if (argc == -1)
- goto done;
-
- if (!ext_mount_remove(mp)) {
- rv =0;
- goto out_free;
- }
-
- rv = spawnv(ap->logopt, prog, (const char * const *) argv);
- if (rv == -1 || (WIFEXITED(rv) && WEXITSTATUS(rv)))
+ if (argc == -1) {
error(ap->logopt,
- "failed to umount program mount at %s", mp);
- else {
+ "failed to allocate args for umount of %s", mp);
rv = 0;
- debug(ap->logopt, "umounted program mount at %s", mp);
- rmdir_path(ap, mp, ap->dev);
+ goto out;
}
-out_free:
+ ret = spawnv(ap->logopt, prog, (const char * const *) argv);
+ rv = WIFEXITED(ret) && !WEXITSTATUS(ret);
free_argv(argc, (const char **) argv);
-
- goto done;
}
- if (ext_mount_remove(mp)) {
- rv = umount_ent(ap, mp);
- if (rv)
- error(ap->logopt,
- "failed to umount external mount %s", mp);
- else
- debug(ap->logopt, "umounted external mount %s", mp);
+ if (is_mounted(mp, MNTS_REAL))
+ error(ap->logopt,
+ "failed to umount external mount %s", mp);
+ else {
+ info(ap->logopt, "umounted external mount %s", mp);
+ rmdir_path(ap, mp, ap->dev);
}
-done:
+ if (remove)
+ ext_mount_remove(mp);
+out:
if (umount)
free(umount);
- free(mp);
-out:
+ if (mp)
+ free(mp);
return rv;
}
diff --git a/modules/parse_amd.c b/modules/parse_amd.c
index 4d98fb024..41e4b2d64 100644
--- a/modules/parse_amd.c
+++ b/modules/parse_amd.c
@@ -1140,7 +1140,7 @@ symlink:
if (entry->sublink) {
/* failed to complete sublink mount */
- umount_amd_ext_mount(ap, entry->fs);
+ umount_amd_ext_mount(ap, entry->fs, 1);
}
out:
return ret;
@@ -1191,7 +1191,7 @@ static int do_generic_mount(struct autofs_point *ap, const char *name,
/* If we have an external mount add it to the list */
if (!ext_mount_add(entry->fs, entry->umount)) {
if (umount)
- umount_amd_ext_mount(ap, entry->fs);
+ umount_amd_ext_mount(ap, entry->fs, 0);
error(ap->logopt, MODPREFIX
"error: could not add external mount %s",
entry->fs);
@@ -1242,7 +1242,7 @@ static int do_nfs_mount(struct autofs_point *ap, const char *name,
/* We might be using an external mount */
if (!ext_mount_add(entry->fs, entry->umount)) {
if (umount)
- umount_amd_ext_mount(ap, entry->fs);
+ umount_amd_ext_mount(ap, entry->fs, 0);
error(ap->logopt, MODPREFIX
"error: could not add external mount %s", entry->fs);
ret = 1;
@@ -1477,7 +1477,7 @@ static int do_program_mount(struct autofs_point *ap,
free(str);
goto done;
}
- umount_amd_ext_mount(ap, entry->fs);
+ umount_amd_ext_mount(ap, entry->fs, 0);
}
error(ap->logopt, MODPREFIX
"%s: failed to mount using %s", entry->type, entry->mount);
@@ -1488,7 +1488,7 @@ static int do_program_mount(struct autofs_point *ap,
done:
rv = do_link_mount(ap, name, entry, 0);
if (rv) {
- if (umount_amd_ext_mount(ap, entry->fs)) {
+ if (!umount_amd_ext_mount(ap, entry->fs, 1)) {
debug(ap->logopt, MODPREFIX
"%s: failed to cleanup external mount at %s",
entry->type, entry->fs);