vfs: fix renameat to retry on ESTALE errors

...as always, rename is the messiest of the bunch. We have to track
whether to retry or not via a separate flag since the error handling
is already quite complex.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Jeff Layton 2012-12-11 12:10:10 -05:00 committed by Al Viro
parent 5d18f8133c
commit c6a9428401

View file

@ -3840,15 +3840,17 @@ SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname,
struct nameidata oldnd, newnd;
struct filename *from;
struct filename *to;
unsigned int lookup_flags = 0;
bool should_retry = false;
int error;
from = user_path_parent(olddfd, oldname, &oldnd, 0);
retry:
from = user_path_parent(olddfd, oldname, &oldnd, lookup_flags);
if (IS_ERR(from)) {
error = PTR_ERR(from);
goto exit;
}
to = user_path_parent(newdfd, newname, &newnd, 0);
to = user_path_parent(newdfd, newname, &newnd, lookup_flags);
if (IS_ERR(to)) {
error = PTR_ERR(to);
goto exit1;
@ -3920,11 +3922,18 @@ exit3:
unlock_rename(new_dir, old_dir);
mnt_drop_write(oldnd.path.mnt);
exit2:
if (retry_estale(error, lookup_flags))
should_retry = true;
path_put(&newnd.path);
putname(to);
exit1:
path_put(&oldnd.path);
putname(from);
if (should_retry) {
should_retry = false;
lookup_flags |= LOOKUP_REVAL;
goto retry;
}
exit:
return error;
}