take post-lookup part of do_last() out of loop

now we can have open_last_lookups() directly from the loop in
path_openat() - the rest of do_last() never returns a symlink
to follow, so we can bloody well leave the loop first.

Rename the rest of that thing from do_last() to do_open() and
make it return an int.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2020-03-05 11:41:29 -05:00
parent 0f70595301
commit c5971b8c63

View file

@ -3220,31 +3220,26 @@ static const char *open_last_lookups(struct nameidata *nd,
/*
* Handle the last step of open()
*/
static const char *do_last(struct nameidata *nd,
static int do_open(struct nameidata *nd,
struct file *file, const struct open_flags *op)
{
int open_flag = op->open_flag;
bool do_truncate;
int acc_mode;
const char *link;
int error;
link = open_last_lookups(nd, file, op);
if (unlikely(link))
return link;
if (!(file->f_mode & FMODE_CREATED))
audit_inode(nd->name, nd->path.dentry, 0);
if (open_flag & O_CREAT) {
if (d_is_dir(nd->path.dentry))
return ERR_PTR(-EISDIR);
return -EISDIR;
error = may_create_in_sticky(nd->dir_mode, nd->dir_uid,
d_backing_inode(nd->path.dentry));
if (unlikely(error))
return ERR_PTR(error);
return error;
}
if ((nd->flags & LOOKUP_DIRECTORY) && !d_can_lookup(nd->path.dentry))
return ERR_PTR(-ENOTDIR);
return -ENOTDIR;
do_truncate = false;
acc_mode = op->acc_mode;
@ -3255,7 +3250,7 @@ static const char *do_last(struct nameidata *nd,
} else if (d_is_reg(nd->path.dentry) && open_flag & O_TRUNC) {
error = mnt_want_write(nd->path.mnt);
if (error)
return ERR_PTR(error);
return error;
do_truncate = true;
}
error = may_open(&nd->path, acc_mode, open_flag);
@ -3271,7 +3266,7 @@ static const char *do_last(struct nameidata *nd,
}
if (do_truncate)
mnt_drop_write(nd->path.mnt);
return ERR_PTR(error);
return error;
}
struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode, int open_flag)
@ -3374,8 +3369,10 @@ static struct file *path_openat(struct nameidata *nd,
} else {
const char *s = path_init(nd, flags);
while (!(error = link_path_walk(s, nd)) &&
(s = do_last(nd, file, op)) != NULL)
(s = open_last_lookups(nd, file, op)) != NULL)
;
if (!error)
error = do_open(nd, file, op);
terminate_walk(nd);
}
if (likely(!error)) {