On 02/05/13 03:05, NeilBrown wrote:
>
>
> Hi Steve,
> I just noticed
>
> commit ebe2826ca571a3959c3b5c8e29686c621f2775cf
> Author: Steve Dickson <steved@xxxxxxxxxx>
> Date: Sat Mar 23 10:30:17 2013 -0400
>
> mountd: regression in crossmounts
>
> Sorry I missed the email you presumably sent me to let me know
> that I had caused a regression.
Yes I should have... That was my bad...
>
> Here is the proper fix.
Yes it does work.. thanks!
The new is committed!
steved.
>
> Thanks,
> NeilBrown
>
>
> Subject: [PATCH] mountd: Fix is_subdirectory again.
>
> commit ebe2826ca571a (mountd: regression in crossmounts)
> said it was:
> Reverting the logic of commit 8e2fb3fc until
> a better solution can be found for the original
> problem.
>
> here is the "something better".
>
> The problem was that is_subdirectory() would also succeed if the two
> directories were the same. This is needed for path_matches() which
> needs to see if the child is same-or-descendant.
>
> So this patch rearranges path_matches() to do the "are they the same"
> test itself and only bother with is_subdirectory() if it they are not
> the same.
>
> So now is_subdirectory() can be strict, and so can be usable for
> subexport(), which needs a strong 'in subdirectory - not the same' test.
>
> Signed-off-by: NeilBrown <neilb@xxxxxxx>
>
> diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
> index 737927c..517aa62 100644
> --- a/utils/mountd/cache.c
> +++ b/utils/mountd/cache.c
> @@ -347,20 +347,26 @@ static char *next_mnt(void **v, char *p)
>
> static int is_subdirectory(char *child, char *parent)
> {
> + /* Check is child is strictly a subdirectory of
> + * parent or a more distant descendant.
> + */
> size_t l = strlen(parent);
>
> - if (strcmp(parent, "/") == 0)
> + if (strcmp(parent, "/") == 0 && child[1] != 0)
> return 1;
>
> - return strcmp(child, parent) == 0
> - || (strncmp(child, parent, l) == 0 && child[l] == '/');
> + return (strncmp(child, parent, l) == 0 && child[l] == '/');
> }
>
> static int path_matches(nfs_export *exp, char *path)
> {
> - if (exp->m_export.e_flags & NFSEXP_CROSSMOUNT)
> - return is_subdirectory(path, exp->m_export.e_path);
> - return strcmp(path, exp->m_export.e_path) == 0;
> + /* Does the path match the export? I.e. is it an
> + * exact match, or does the export have CROSSMOUNT, and path
> + * is a descendant?
> + */
> + return strcmp(path, exp->m_export.e_path) == 0
> + || ((exp->m_export.e_flags & NFSEXP_CROSSMOUNT)
> + && is_subdirectory(path, exp->m_export.e_path));
> }
>
> static int
> @@ -369,15 +375,13 @@ export_matches(nfs_export *exp, char *dom, char *path, struct addrinfo *ai)
> return path_matches(exp, path) && client_matches(exp, dom, ai);
> }
>
> -/* True iff e1 is a child of e2 and e2 has crossmnt set: */
> +/* True iff e1 is a child of e2 (or descendant) and e2 has crossmnt set: */
> static bool subexport(struct exportent *e1, struct exportent *e2)
> {
> char *p1 = e1->e_path, *p2 = e2->e_path;
> - size_t l2 = strlen(p2);
>
> return e2->e_flags & NFSEXP_CROSSMOUNT
> - && strncmp(p1, p2, l2) == 0
> - && p1[l2] == '/';
> + && is_subdirectory(p1, p2);
> }
>
> struct parsed_fsid {
>
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