On Fri, Jul 13, 2007 at 11:21:23AM +0200, Kay Sievers wrote:
> On 7/12/07, Matthias Koenig <mkoenig@xxxxxxx> wrote:
> >it would be nice to have a mount option "nofail" indicating
> >that mount should not return an error if the device does not
> >exit. This is useful for hotpluggable devices which are configured
> >in fstab and might not exist at boot time.
>
> We should probably ignore failures of a failed mount syscall too?
> The device node may exist, even when there is no kernel device at the
> moment as as some subsystems like md create a bunch of nodes
> unconditionally.
Yes. It seems mount(2) returns ENXIO, ENOTBLK, ENOENT or ENOTDIR when
something is wrong with source device.
Please, see updated patch below.
Karel
>From a2b13fb0bced6525c2e47cdc6f4f9ebb8259f7b4 Mon Sep 17 00:00:00 2001
From: Matthias Koenig <mkoenig@xxxxxxx>
Date: Mon, 17 Dec 2007 11:33:20 +0100
Subject: [PATCH] mount: "nofail" mount option
It would be nice to have a mount option "nofail" indicating that mount
should not return an error if the device does not exit. This is useful
for hotpluggable devices which are configured in fstab and __might__
not exist at boot time.
Co-Author: Karel Zak <kzak@xxxxxxxxxx>
Signed-off-by: Matthias Koenig <mkoenig@xxxxxxx>
Signed-off-by: Karel Zak <kzak@xxxxxxxxxx>
---
mount/mount.8 | 3 +++
mount/mount.c | 21 +++++++++++++++++----
2 files changed, 20 insertions(+), 4 deletions(-)
diff --git a/mount/mount.8 b/mount/mount.8
index 54b11d4..ce52dd8 100644
--- a/mount/mount.8
+++ b/mount/mount.8
@@ -615,6 +615,9 @@ This option implies the options
(unless overridden by subsequent options, as in the option line
.BR group,dev,suid ).
.TP
+.B nofail
+Do not report errors for this device if it does not exist.
+.TP
.B mand
Allow mandatory locks on this filesystem. See
.BR fcntl (2).
diff --git a/mount/mount.c b/mount/mount.c
index 917f62a..0688c57 100644
--- a/mount/mount.c
+++ b/mount/mount.c
@@ -176,9 +176,12 @@ static const struct opt_map opt_map[] = {
{ "norelatime", 0, 1, MS_RELATIME }, /* Update access time without regard
to mtime/ctime */
#endif
+ { "nofail", 0, 0, MS_COMMENT}, /* Do not fail if ENOENT on dev */
{ NULL, 0, 0, 0 }
};
+static int opt_nofail = 0;
+
static const char *opt_loopdev, *opt_vfstype, *opt_offset, *opt_encryption,
*opt_speed, *opt_comment, *opt_uhelper;
@@ -383,6 +386,8 @@ parse_opt(char *opt, int *mask, char **extra_opts) {
verbose = 0;
}
#endif
+ if (streq(opt, "nofail"))
+ opt_nofail = 1;
return;
}
@@ -1198,9 +1203,11 @@ try_mount_one (const char *spec0, const char *node0, const char *types0,
else if (stat (node, &statbuf))
error (_("mount: mount point %s is a symbolic link to nowhere"),
node);
- else if (stat (spec, &statbuf))
+ else if (stat (spec, &statbuf)) {
+ if (opt_nofail)
+ goto out;
error (_("mount: special device %s does not exist"), spec);
- else {
+ } else {
errno = mnt_err;
perror("mount");
}
@@ -1208,10 +1215,12 @@ try_mount_one (const char *spec0, const char *node0, const char *types0,
case ENOTDIR:
if (stat (node, &statbuf) || ! S_ISDIR(statbuf.st_mode))
error (_("mount: mount point %s is not a directory"), node);
- else if (stat (spec, &statbuf) && errno == ENOTDIR)
+ else if (stat (spec, &statbuf) && errno == ENOTDIR) {
+ if (opt_nofail)
+ goto out;
error (_("mount: special device %s does not exist\n"
" (a path prefix is not a directory)\n"), spec);
- else {
+ } else {
errno = mnt_err;
perror("mount");
}
@@ -1296,6 +1305,8 @@ try_mount_one (const char *spec0, const char *node0, const char *types0,
break;
}
case ENOTBLK:
+ if (opt_nofail)
+ goto out;
if (stat (spec, &statbuf)) /* strange ... */
error (_("mount: %s is not a block device, and stat fails?"), spec);
else if (S_ISBLK(statbuf.st_mode))
@@ -1308,6 +1319,8 @@ try_mount_one (const char *spec0, const char *node0, const char *types0,
error (_("mount: %s is not a block device"), spec);
break;
case ENXIO:
+ if (opt_nofail)
+ goto out;
error (_("mount: %s is not a valid block device"), spec); break;
case EACCES: /* pre-linux 1.1.38, 1.1.41 and later */
case EROFS: /* linux 1.1.38 and later */
--
1.5.3.1
-
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