On Sat, Jun 26, 2021 at 07:07:42AM +0200, Sebastien Marie wrote:
> Hi,
>
> The following diff removes LOCKLEAF from NDINIT. The code doesn't
> doesn't need it: the returned vnode is released immediately. The
> string path is built from the namei() call using REALPATH, during
> directories traversal.
>
> Without LOCKLEAF, calling vrele() only is enough if namei() found a
> file, instead of calling VOP_UNLOCK() + vrele().
>
> Comments or OK ?
> --
> Sebastien Marie
>
> diff dca1bd8d5621788b92aad3f944ac9999965773e2
> 545f8aacd74a1f793d1289475eb1c3f84d649e06
> blob - 840ea5453e13604cb38b6a5d580370053386ce71
> blob + fe240bb520b142726f358dfec4eaf6f26de151c1
> --- sys/kern/vfs_syscalls.c
> +++ sys/kern/vfs_syscalls.c
> @@ -916,36 +916,35 @@ sys___realpath(struct proc *p, void *v, register_t *re
> }
>
> free(cwdbuf, M_TEMP, cwdlen);
> }
>
> /* find root "/" or "//" */
> for (c = pathname; *c != '\0'; c++) {
> if (*c != '/')
> break;
> }
> - NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | SAVENAME | REALPATH,
> - UIO_SYSSPACE, pathname, p);
> + NDINIT(&nd, LOOKUP, FOLLOW | SAVENAME | REALPATH, UIO_SYSSPACE,
> + pathname, p);
>
> nd.ni_cnd.cn_rpbuf = rpbuf;
> nd.ni_cnd.cn_rpi = strlen(rpbuf);
>
> nd.ni_pledge = PLEDGE_RPATH;
> nd.ni_unveil = UNVEIL_READ;
> if ((error = namei(&nd)) != 0)
> goto end;
>
> - /* release lock and reference from namei */
> - if (nd.ni_vp) {
> - VOP_UNLOCK(nd.ni_vp);
> + /* release reference from namei */
> + if (nd.ni_vp)
> vrele(nd.ni_vp);
> - }
> +
> error = copyoutstr(nd.ni_cnd.cn_rpbuf, SCARG(uap, resolved),
> MAXPATHLEN, NULL);
>
> #ifdef KTRACE
> if (KTRPOINT(p, KTR_NAMEI))
> ktrnamei(p, nd.ni_cnd.cn_rpbuf);
> #endif
> pool_put(&namei_pool, nd.ni_cnd.cn_pnbuf);
> end:
> pool_put(&namei_pool, rpbuf);
>
Makes sense. OK claudio@
--
:wq Claudio
