path_openat(): take O_PATH handling out of do_last()

do_last() and lookup_open() simpler that way and so does O_PATH
itself.  As it bloody well should: we find what the pathname
resolves to, same way as in stat() et.al. and associate it with
FMODE_PATH struct file.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-04-26 00:02:50 -04:00
parent 3b0a3c1ac1
commit 6ac087099e

View File

@ -3019,7 +3019,7 @@ static int lookup_open(struct nameidata *nd, struct path *path,
goto out_no_open;
}
if ((nd->flags & LOOKUP_OPEN) && dir_inode->i_op->atomic_open) {
if (dir_inode->i_op->atomic_open) {
return atomic_open(nd, dentry, path, file, op, got_write,
need_lookup, opened);
}
@ -3219,7 +3219,7 @@ static int do_last(struct nameidata *nd,
return error;
}
audit_inode(nd->name, nd->path.dentry, 0);
if (unlikely(d_is_symlink(nd->path.dentry)) && !(open_flag & O_PATH)) {
if (unlikely(d_is_symlink(nd->path.dentry))) {
error = -ELOOP;
goto out;
}
@ -3239,11 +3239,9 @@ static int do_last(struct nameidata *nd,
got_write = true;
}
finish_open_created:
if (likely(!(open_flag & O_PATH))) {
error = may_open(&nd->path, acc_mode, open_flag);
if (error)
goto out;
}
error = may_open(&nd->path, acc_mode, open_flag);
if (error)
goto out;
BUG_ON(*opened & FILE_OPENED); /* once it's opened, it's opened */
error = vfs_open(&nd->path, file, current_cred());
if (!error) {
@ -3357,6 +3355,18 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags,
return error;
}
static int do_o_path(struct nameidata *nd, unsigned flags, struct file *file)
{
struct path path;
int error = path_lookupat(nd, flags, &path);
if (!error) {
audit_inode(nd->name, path.dentry, 0);
error = vfs_open(&path, file, current_cred());
path_put(&path);
}
return error;
}
static struct file *path_openat(struct nameidata *nd,
const struct open_flags *op, unsigned flags)
{
@ -3376,6 +3386,13 @@ static struct file *path_openat(struct nameidata *nd,
goto out2;
}
if (unlikely(file->f_flags & O_PATH)) {
error = do_o_path(nd, flags, file);
if (!error)
opened |= FILE_OPENED;
goto out2;
}
s = path_init(nd, flags);
if (IS_ERR(s)) {
put_filp(file);