Messages in this thread Patch in this message | | | From | Namhyung Kim <> | Subject | [PATCH v2] init: replace sys_mount() to do_mount() | Date | Tue, 17 Aug 2010 23:38:09 +0900 |
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sys_mount() just copies all (string) arguments from user space to kernel and calls do_mount(). In this case we have all args in kernel already so there is no need to call sys_mount(). One thing we should take care is 'data' have to be in a page unless it is NULL. Do it manually.
Signed-off-by: Namhyung Kim <namhyung@gmail.com> ---
I found 3 more calls in init/do_mounts_initrd.c and merged them. Please apply this instead.
2010-08-17 (Tue), 15:41 +0200, Arnd Bergmann: > Maybe you can fix that as well in the same patch and move this safeguard > into the copy_mount_options() function? I guess ideally we'd even mark > the arguments to do_mount() as pointers to const, but that might create > an excessive amount of churn.
Arnd, thanks for reviewing and the suggestion but I think that should be in a different patch (set).
init/do_mounts.c | 18 ++++++++++++++++-- init/do_mounts_initrd.c | 6 +++--- 2 files changed, 19 insertions(+), 5 deletions(-)
diff --git a/init/do_mounts.c b/init/do_mounts.c index 02e3ca4..8eabff6 100644 --- a/init/do_mounts.c +++ b/init/do_mounts.c @@ -217,7 +217,21 @@ static void __init get_fs_names(char *page)
static int __init do_mount_root(char *name, char *fs, int flags, void *data) { - int err = sys_mount(name, "/root", fs, flags, data); + int err; + unsigned long data_page = 0; + + if (data) { + /* data should be in a page */ + data_page = __get_free_page(GFP_KERNEL); + if (!data_page) + return -ENOMEM; + strlcpy((char *) data_page, data, PAGE_SIZE); + } + + err = do_mount(name, "/root", fs, flags, (void *) data_page); + + if (data_page) + free_page(data_page); if (err) return err;
@@ -417,6 +431,6 @@ void __init prepare_namespace(void) mount_root(); out: devtmpfs_mount("dev"); - sys_mount(".", "/", NULL, MS_MOVE, NULL); + do_mount(".", "/", NULL, MS_MOVE, NULL); sys_chroot("."); } diff --git a/init/do_mounts_initrd.c b/init/do_mounts_initrd.c index 2b10853..8355501 100644 --- a/init/do_mounts_initrd.c +++ b/init/do_mounts_initrd.c @@ -48,7 +48,7 @@ static void __init handle_initrd(void) old_fd = sys_open("/old", 0, 0); /* move initrd over / and chdir/chroot in initrd root */ sys_chdir("/root"); - sys_mount(".", "/", NULL, MS_MOVE, NULL); + do_mount(".", "/", NULL, MS_MOVE, NULL); sys_chroot(".");
/* @@ -66,7 +66,7 @@ static void __init handle_initrd(void)
/* move initrd to rootfs' /old */ sys_fchdir(old_fd); - sys_mount("/", ".", NULL, MS_MOVE, NULL); + do_mount("/", ".", NULL, MS_MOVE, NULL); /* switch root and cwd back to / of rootfs */ sys_fchdir(root_fd); sys_chroot("."); @@ -82,7 +82,7 @@ static void __init handle_initrd(void) mount_root();
printk(KERN_NOTICE "Trying to move old root to /initrd ... "); - error = sys_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL); + error = do_mount("/old", "/root/initrd", NULL, MS_MOVE, NULL); if (!error) printk("okay\n"); else { -- 1.7.0.4
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