Attachment 305085 Details for Bug 442618 – Patcg to check for nohide mounts

[patch] Patcg to check for nohide mounts

autofs-5.0.3-nfs4-nohide-check.patch (text/plain), 6.26 KB, created by Ian Kent on 2008-05-12 07:03:00 UTC

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Creator: Ian Kent

Created: 2008-05-12 07:03:00 UTC

Size: 6.26 KB

patch

obsolete

>autofs 5.0.3 - check for nohide mounts
>
>From: Ian Kent <raven@themaw.net>
>
>If a server exports file systems with the nohide option
>autofs will mistakenly over mount them when it constructs
>and mounts its multi-mount triggers.
>
>This patch makes autofs check for nohide mounts and ignores
>them if the kernel mounts them while it mounts multi-mount
>triggers.
>
>We don't want to fight with NFS over mounting these because
>it confuses autofs and they magically go away when the owner
>mount is umounted. This isn't ideal because autofs will mount
>the nohide exports while constructing its multi-mount triggers
>but it is unavoidable at the moment.
>---
>
> daemon/direct.c     |   26 ++++++++++++++++++--------
> include/automount.h |    4 ++++
> lib/parse_subs.c    |   26 ++++++++++++++++++--------
> 3 files changed, 40 insertions(+), 16 deletions(-)
>
>
>diff --git a/daemon/direct.c b/daemon/direct.c
>index a9dda87..c67f38a 100644
>--- a/daemon/direct.c
>+++ b/daemon/direct.c
>@@ -664,12 +664,12 @@ int mount_autofs_offset(struct autofs_point *ap, struct mapent *me)
> 		if (ap->state != ST_READMAP)
> 			warn(ap->logopt,
> 			      "trigger %s already mounted", me->key);
>-		return 0;
>+		return MOUNT_OFFSET_OK;
> 	}
> 
> 	if (me->ioctlfd != -1) {
> 		error(ap->logopt, "active offset mount %s", me->key);
>-		return -1;
>+		return MOUNT_OFFSET_FAIL;
> 	}
> 
> 	status = pthread_once(&key_mnt_params_once, key_mnt_params_init);
>@@ -683,7 +683,7 @@ int mount_autofs_offset(struct autofs_point *ap, struct mapent *me)
> 			crit(ap->logopt,
> 			  "mnt_params value create failed for offset mount %s",
> 			  me->key);
>-			return 0;
>+			return MOUNT_OFFSET_OK;
> 		}
> 		mp->options = NULL;
> 
>@@ -697,12 +697,22 @@ int mount_autofs_offset(struct autofs_point *ap, struct mapent *me)
> 	if (!mp->options) {
> 		mp->options = make_options_string(ap->path, ap->kpipefd, "offset");
> 		if (!mp->options)
>-			return 0;
>+			return MOUNT_OFFSET_OK;
> 	}
> 
> 	/* In case the directory doesn't exist, try to mkdir it */
> 	if (mkdir_path(me->key, 0555) < 0) {
> 		if (errno == EEXIST) {
>+			/*
>+			 * If the mount point directory is a real mount
>+			 * and it isn't the root offset then it must be
>+			 * a "nohide" mount, automounted by the kernel NFS
>+			 * client.
>+			 */
>+			if (me->multi != me &&
>+			    is_mounted(_PROC_MOUNTS, me->key, MNTS_REAL))
>+				return MOUNT_OFFSET_IGNORE;
>+
> 			/* 
> 			 * If we recieve an error, and it's EEXIST
> 			 * we know the directory was not created.
>@@ -721,13 +731,13 @@ int mount_autofs_offset(struct autofs_point *ap, struct mapent *me)
> 			debug(ap->logopt,
> 			     "can't create mount directory: %s, %s",
> 			     me->key, estr);
>-			return -1;
>+			return MOUNT_OFFSET_FAIL;
> 		} else {
> 			char *estr = strerror_r(errno, buf, MAX_ERR_BUF);
> 			crit(ap->logopt,
> 			     "failed to create mount directory: %s, %s",
> 			     me->key, estr);
>-			return -1;
>+			return MOUNT_OFFSET_FAIL;
> 		}
> 	} else {
> 		/* No errors so the directory was successfully created */
>@@ -787,7 +797,7 @@ int mount_autofs_offset(struct autofs_point *ap, struct mapent *me)
> 
> 	debug(ap->logopt, "mounted trigger %s", me->key);
> 
>-	return 0;
>+	return MOUNT_OFFSET_OK;
> 
> out_close:
> 	close(ioctlfd);
>@@ -797,7 +807,7 @@ out_err:
> 	if (stat(me->key, &st) == 0 && me->dir_created)
> 		 rmdir_path(ap, me->key, st.st_dev);
> 
>-	return -1;
>+	return MOUNT_OFFSET_FAIL;
> }
> 
> static int expire_direct(int ioctlfd, const char *path, unsigned int when, unsigned int logopt)
>diff --git a/include/automount.h b/include/automount.h
>index cd8ce7b..d59be77 100644
>--- a/include/automount.h
>+++ b/include/automount.h
>@@ -468,6 +468,10 @@ struct autofs_point {
> 
> /* Standard functions used by daemon or modules */
> 
>+#define	MOUNT_OFFSET_OK		0
>+#define	MOUNT_OFFSET_FAIL	-1
>+#define MOUNT_OFFSET_IGNORE	-2
>+
> void *handle_mounts(void *arg);
> int umount_multi(struct autofs_point *ap, const char *path, int incl);
> int send_ready(unsigned logopt, int ioctlfd, unsigned int wait_queue_token);
>diff --git a/lib/parse_subs.c b/lib/parse_subs.c
>index 5422fef..27cb0fc 100644
>--- a/lib/parse_subs.c
>+++ b/lib/parse_subs.c
>@@ -390,7 +390,7 @@ int mount_multi_triggers(struct autofs_point *ap, char *root, struct mapent *me,
> 	struct list_head *pos = NULL;
> 	unsigned int fs_path_len;
> 	unsigned int mounted;
>-	int start;
>+	int ret, start;
> 
> 	fs_path_len = strlen(root) + strlen(base);
> 	if (fs_path_len > PATH_MAX)
>@@ -411,15 +411,25 @@ int mount_multi_triggers(struct autofs_point *ap, char *root, struct mapent *me,
> 		}
> 
> 		oe = cache_lookup_offset(base, offset, start, &me->multi_list);
>-		if (!oe)
>+		if (!oe || !oe->mapent)
> 			goto cont;
> 
> 		debug(ap->logopt, "mount offset %s", oe->key);
> 
>-		if (mount_autofs_offset(ap, oe) < 0)
>-			warn(ap->logopt, "failed to mount offset");
>-		else
>+		ret = mount_autofs_offset(ap, oe);
>+		if (ret >= MOUNT_OFFSET_OK)
> 			mounted++;
>+		else {
>+			if (ret != MOUNT_OFFSET_IGNORE)
>+				warn(ap->logopt, "failed to mount offset");
>+			else {
>+				debug(ap->logopt,
>+				      "ignoring \"nohide\" trigger %s",
>+				      oe->key);
>+				free(oe->mapent);
>+				oe->mapent = NULL;
>+			}
>+		}
> cont:
> 		offset = cache_get_offset(base,
> 				offset, start, &me->multi_list, &pos);
>@@ -457,7 +467,7 @@ int umount_multi_triggers(struct autofs_point *ap, char *root, struct mapent *me
> 
> 		oe = cache_lookup_offset(mm_base, offset, start, &me->multi_list);
> 		/* root offset is a special case */
>-		if (!oe || (strlen(oe->key) - start) == 1)
>+		if (!oe || !oe->mapent || (strlen(oe->key) - start) == 1)
> 			continue;
> 
> 		/*
>@@ -481,7 +491,7 @@ int umount_multi_triggers(struct autofs_point *ap, char *root, struct mapent *me
> 	while ((offset = cache_get_offset(mm_base, offset, start, mm_root, &pos))) {
> 		oe = cache_lookup_offset(mm_base, offset, start, &me->multi_list);
> 		/* root offset is a special case */
>-		if (!oe || (strlen(oe->key) - start) == 1)
>+		if (!oe || !oe->mapent || (strlen(oe->key) - start) == 1)
> 			continue;
> 
> 		debug(ap->logopt, "umount offset %s", oe->key);
>@@ -505,7 +515,7 @@ int umount_multi_triggers(struct autofs_point *ap, char *root, struct mapent *me
> 		if (is_mounted(_PATH_MOUNTED, root, MNTS_REAL)) {
> 			info(ap->logopt, "unmounting dir = %s", root);
> 			if (umount_ent(ap, root)) {
>-				if (!mount_multi_triggers(ap, root, me, "/"))
>+				if (mount_multi_triggers(ap, root, me, "/") < 0)
> 					warn(ap->logopt,
> 					     "failed to remount offset triggers");
> 				return left++;

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Attachments on bug 442618: 305085