atomic_open(): massage the create_error logics a bit

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-04-27 02:36:39 -04:00
parent 9d0728e16e
commit 55db2fd936

View file

@ -2855,33 +2855,30 @@ static int atomic_open(struct nameidata *nd, struct dentry *dentry,
* Another problem is returing the "right" error value (e.g. for an
* O_EXCL open we want to return EEXIST not EROFS).
*/
if (((open_flag & (O_CREAT | O_TRUNC)) ||
(open_flag & O_ACCMODE) != O_RDONLY) && unlikely(!got_write)) {
if (!(open_flag & O_CREAT)) {
/*
* No O_CREATE -> atomicity not a requirement -> fall
* back to lookup + open
*/
goto no_open;
} else if (open_flag & (O_EXCL | O_TRUNC)) {
/* Fall back and fail with the right error */
create_error = -EROFS;
goto no_open;
} else {
/* No side effects, safe to clear O_CREAT */
create_error = -EROFS;
open_flag &= ~O_CREAT;
}
}
if (open_flag & O_CREAT) {
error = may_o_create(&nd->path, dentry, mode);
if (error) {
create_error = error;
if (open_flag & O_EXCL)
if (unlikely(!got_write)) {
create_error = -EROFS;
if (open_flag & (O_EXCL | O_TRUNC)) {
/* Fall back and fail with the right error */
goto no_open;
}
/* No side effects, safe to clear O_CREAT */
open_flag &= ~O_CREAT;
} else {
create_error = may_o_create(&nd->path, dentry, mode);
if (create_error) {
if (open_flag & O_EXCL)
goto no_open;
open_flag &= ~O_CREAT;
}
}
} else if ((open_flag & (O_TRUNC|O_WRONLY|O_RDWR)) &&
unlikely(!got_write)) {
/*
* No O_CREATE -> atomicity not a requirement -> fall
* back to lookup + open
*/
goto no_open;
}
if (nd->flags & LOOKUP_DIRECTORY)