allow link_path_walk() to take ERR_PTR()

There is a check for IS_ERR(name) immediately upstream of each call
of link_path_walk(name, nd), with positives treated as if link_path_walk()
failed with PTR_ERR(name).  Taking that check into link_path_walk() itself
simplifies things nicely.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2018-07-09 16:33:23 -04:00
parent edc2b1da77
commit 9b5858e99a

View File

@ -2028,6 +2028,8 @@ static int link_path_walk(const char *name, struct nameidata *nd)
{
int err;
if (IS_ERR(name))
return PTR_ERR(name);
while (*name=='/')
name++;
if (!*name)
@ -2265,12 +2267,7 @@ static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path
const char *s = path_init(nd, flags);
int err;
if (IS_ERR(s)) {
terminate_walk(nd);
return PTR_ERR(s);
}
if (unlikely(flags & LOOKUP_DOWN)) {
if (unlikely(flags & LOOKUP_DOWN) && !IS_ERR(s)) {
err = handle_lookup_down(nd);
if (unlikely(err < 0)) {
terminate_walk(nd);
@ -2281,10 +2278,6 @@ static int path_lookupat(struct nameidata *nd, unsigned flags, struct path *path
while (!(err = link_path_walk(s, nd))
&& ((err = lookup_last(nd)) > 0)) {
s = trailing_symlink(nd);
if (IS_ERR(s)) {
err = PTR_ERR(s);
break;
}
}
if (!err)
err = complete_walk(nd);
@ -2331,12 +2324,7 @@ static int path_parentat(struct nameidata *nd, unsigned flags,
struct path *parent)
{
const char *s = path_init(nd, flags);
int err;
if (IS_ERR(s)) {
terminate_walk(nd);
return PTR_ERR(s);
}
err = link_path_walk(s, nd);
int err = link_path_walk(s, nd);
if (!err)
err = complete_walk(nd);
if (!err) {
@ -2663,17 +2651,10 @@ path_mountpoint(struct nameidata *nd, unsigned flags, struct path *path)
{
const char *s = path_init(nd, flags);
int err;
if (IS_ERR(s)) {
terminate_walk(nd);
return PTR_ERR(s);
}
while (!(err = link_path_walk(s, nd)) &&
(err = mountpoint_last(nd)) > 0) {
s = trailing_symlink(nd);
if (IS_ERR(s)) {
err = PTR_ERR(s);
break;
}
}
if (!err) {
*path = nd->path;
@ -3510,19 +3491,10 @@ static struct file *path_openat(struct nameidata *nd,
}
s = path_init(nd, flags);
if (IS_ERR(s)) {
terminate_walk(nd);
fput(file);
return ERR_CAST(s);
}
while (!(error = link_path_walk(s, nd)) &&
(error = do_last(nd, file, op)) > 0) {
nd->flags &= ~(LOOKUP_OPEN|LOOKUP_CREATE|LOOKUP_EXCL);
s = trailing_symlink(nd);
if (IS_ERR(s)) {
error = PTR_ERR(s);
break;
}
}
terminate_walk(nd);
out2: