Hi Stanislav,
I've looked more into it and I found some issues with the patch:
Stanislav Brabec <sbrabec@xxxxxxx> writes:
> + while ((c = *subpath++))
^^^ subpath is always post-incremented
> + {
> + if (c == '/') {
> + if (!last_is_slash) {
> + component_no++;
> + if (component_no == 3)
> + break;
^^^ when we break subpath
actually 1 past the /
> + }
> + last_is_slash = true;
> + } else
> + last_is_slash = false;
> + }
> + if (component_no == 3) {
> + int subpath_len = strlen(subpath);
> + if (strncmp(root, subpath, subpath_len)) {
^^^ ^^^ hence why here
with //localhost/share/dir in fstab we never get here
p root => $1 = 0x7f28aa9977d0 "/dir"
p subpath => $2 = 0x7f28aa9979a2 "dir"
> + if (*(root + subpath_len + 1) == 0)
> + return "/";
> + return root + subpath_len + 1;
> + }
> + }
> + DBG(FS, ul_debugobj(fs, "cifs: leading part of root \"%s\" does
> not equal to mounted source subdir \"%s\"; should not happen", root,
> src));
^^^ this message gets printed with //localhost/share //localhost/share/
That being said, I could not make your patch fail i.e. make mount -a
mount the fs twice. So I'm not sure what happens there... I thought I
would give it a try.
I'm attaching a simpler patch that makes uses of streq_paths() in
lib/strutils.c (Note: streq_paths() and next_path_segment() have to be
backported for older versions of util-linux).
From a29acba1a7c71cdbfc1cc98f2905bfaf19b97a29 Mon Sep 17 00:00:00 2001
From: Aurelien Aptel <aaptel@xxxxxxxx>
Date: Thu, 1 Sep 2016 13:57:42 +0200
Subject: [PATCH] libmount/src/tab.c: fix mount -a for cifs
when mounting a cifs share, the src is actually an UNC path which can in
in several forms:
simple: //host/share, //host/share/
including subpath: //host/share/sub/path
to check if the cifs fs is mounted we have to extract the subpath and
compare *that* to the root.
Signed-off-by: Aurelien Aptel <aaptel@xxxxxxxx>
---
libmount/src/tab.c | 27 ++++++++++++++++++++++++---
1 file changed, 24 insertions(+), 3 deletions(-)
diff --git a/libmount/src/tab.c b/libmount/src/tab.c
index 341e5e3..9c49ec8 100644
--- a/libmount/src/tab.c
+++ b/libmount/src/tab.c
@@ -1329,6 +1329,20 @@ err:
}
#endif /* HAVE_BTRFS_SUPPORT */
+static const char *get_cifs_unc_subdir_path (const char *unc)
+{
+ /*
+ * 1 or more slash: %*[/]
+ * 1 or more non-slash: %*[^/]
+ * number of byte read: %n
+ */
+ int share_end = 0;
+ int r = sscanf(unc, "%*[/]%*[^/]%*[/]%*[^/]%n", &share_end);
+ if (r == EOF || share_end == 0)
+ return NULL;
+ return unc + share_end;
+}
+
/*
* tb: /proc/self/mountinfo
* fs: filesystem
@@ -1563,9 +1577,16 @@ int mnt_table_is_fs_mounted(struct libmnt_table *tb, struct libmnt_fs *fstab_fs)
}
if (root) {
- const char *r = mnt_fs_get_root(fs);
- if (!r || strcmp(r, root) != 0)
- continue;
+ if (strcmp(mnt_fs_get_fstype(fs), "cifs") == 0) {
+ const char *unc_subdir = get_cifs_unc_subdir_path(src);
+ const char *path_on_fs = mnt_fs_get_root(fs);
+ if (!unc_subdir || !path_on_fs || !streq_paths(unc_subdir, path_on_fs))
+ continue;
+ } else {
+ const char *r = mnt_fs_get_root(fs);
+ if (!r || strcmp(r, root) != 0)
+ continue;
+ }
}
/*
--
2.1.4
Attachment:
signature.asc
Description: PGP signature
