| From | Arnd Bergmann <> | Date | Thu, 15 Mar 2018 21:11:27 +0100 | Subject | Re: [PATCH v2 14/36] fs: add ksys_mount() helper; remove in-kernel calls to sys_mount() |
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On Thu, Mar 15, 2018 at 8:05 PM, Dominik Brodowski <linux@dominikbrodowski.net> wrote: > Using this helper allows us to avoid the in-kernel calls to the sys_mount() > syscall. > > Cc: Alexander Viro <viro@zeniv.linux.org.uk> > Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
> diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c > index 50025d7959cb..4afb04686c8e 100644 > --- a/drivers/base/devtmpfs.c > +++ b/drivers/base/devtmpfs.c > @@ -356,7 +356,8 @@ int devtmpfs_mount(const char *mntdir) > if (!thread) > return 0; > > - err = sys_mount("devtmpfs", (char *)mntdir, "devtmpfs", MS_SILENT, NULL); > + err = ksys_mount("devtmpfs", (char *)mntdir, "devtmpfs", MS_SILENT, > + NULL); > if (err) > printk(KERN_INFO "devtmpfs: error mounting %i\n", err); > else > @@ -382,7 +383,7 @@ static int devtmpfsd(void *p) > *err = sys_unshare(CLONE_NEWNS); > if (*err) > goto out; > - *err = sys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options); > + *err = ksys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options); > if (*err) > goto out; > sys_chdir("/.."); /* will traverse into overmounted root */
Shouldn't the callers of sys_mount just call do_mount() instead?
As I understand it, sys_mount is already a wrapper around do_mount() that copies its arguments from user space, but we don't need that when called from inside the kernel.
Arnd
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