Justus Winter, le Wed 20 Nov 2013 11:10:08 +0100, a écrit :
> Previously the mtab detector tried to detect whether it talks to
> itself by comparing the control port of the translator it currently
> visits with its own. This was done to prevent deadlocks. However, this
> did not detect non-trivial loops, i.e. two mtab translators would
> still dead-lock each other.
>
> Now that it is safe to actually file_name_lookup the root node of a
> mtab translator without triggering the generation of content, this
> logic can just be omitted.
Ack.
> * trans/mtab.c (mtab_populate): Remove the loop detection logic.
> ---
> trans/mtab.c | 43 +++++++++++--------------------------------
> 1 file changed, 11 insertions(+), 32 deletions(-)
>
> diff --git a/trans/mtab.c b/trans/mtab.c
> index b1a3939..d3c3583 100644
> --- a/trans/mtab.c
> +++ b/trans/mtab.c
> @@ -286,7 +286,6 @@ mtab_populate (struct mtab *mtab, const char *path, int
> insecure)
>
> /* These resources are freed in the epilogue. */
> file_t node = MACH_PORT_NULL;
> - fsys_t fsys = MACH_PORT_NULL;
> char *argz = NULL;
> size_t argz_len = 0;
> char **argv = NULL;
> @@ -299,16 +298,16 @@ mtab_populate (struct mtab *mtab, const char *path, int
> insecure)
> char *children = NULL;
> size_t children_len = 0;
>
> - /* Get the underlying node. */
> - node = file_name_lookup (path, O_NOTRANS, 0666);
> - if (node == MACH_PORT_NULL)
> - {
> - err = errno;
> - goto errout;
> - }
> -
> if (! insecure)
> {
> + /* Get the underlying node. */
> + node = file_name_lookup (path, O_NOTRANS, 0666);
> + if (node == MACH_PORT_NULL)
> + {
> + err = errno;
> + goto errout;
> + }
> +
> /* Check who owns the node the translator is bound to. */
> io_statbuf_t st;
> err = io_stat (node, &st);
> @@ -320,28 +319,11 @@ mtab_populate (struct mtab *mtab, const char *path, int
> insecure)
> err = EPERM;
> goto errout;
> }
> - }
>
> - err = file_get_translator_cntl (node, &fsys);
> - if (err == EPERM)
> - /* If we do not have permission to do that, it cannot be a node
> - bound to our control port, so ignore this error. */
> - err = 0;
> -
> - if (err == ENXIO && strcmp (path, "/") == 0)
> - /* The root translator fails differently, but this can't be bound
> - to our control port either, so ignore this error. */
> - err = 0;
> -
> - if (err)
> - return err;
> -
> - if (control && control->pi.port_right == fsys)
> - /* This node is bound to our control port, ignore it. */
> - goto errout;
> + mach_port_deallocate (mach_task_self (), node);
> + }
>
> - /* Re-do the lookup without O_NOTRANS to get the root node. */
> - mach_port_deallocate (mach_task_self (), node);
> + /* (Re-)do the lookup without O_NOTRANS to get the root node. */
> node = file_name_lookup (path, 0, 0666);
> if (node == MACH_PORT_NULL)
> {
> @@ -465,9 +447,6 @@ mtab_populate (struct mtab *mtab, const char *path, int
> insecure)
> if (node != MACH_PORT_NULL)
> mach_port_deallocate (mach_task_self (), node);
>
> - if (fsys != MACH_PORT_NULL)
> - mach_port_deallocate (mach_task_self (), fsys);
> -
> if (argz)
> vm_deallocate (mach_task_self (), (vm_address_t) argz, argz_len);
>
> --
> 1.7.10.4
>
--
Samuel
<A> mr - remove the home of correct users who accidentally enter mr
<A> instead of rm
