diff options
| author | Jeff Layton <jlayton@kernel.org> | 2019-10-30 12:15:10 -0400 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2019-11-05 15:42:44 +0100 |
| commit | 5bb5e6ee6f5c557dcd19822eccd7bcced1e1a410 (patch) | |
| tree | f8a1b79914122633ee4e1ec4139d9b8ff751f4bd /fs | |
| parent | 1f08529c84cfecaf1261ed9b7e17fab18541c58f (diff) | |
ceph: don't try to handle hashed dentries in non-O_CREAT atomic_open
If ceph_atomic_open is handed a !d_in_lookup dentry, then that means
that it already passed d_revalidate so we *know* that it's negative (or
at least was very recently). Just return -ENOENT in that case.
This also addresses a subtle bug in dentry handling. Non-O_CREAT opens
call atomic_open with the parent's i_rwsem shared, but calling
d_splice_alias on a hashed dentry requires the exclusive lock.
If ceph_atomic_open receives a hashed, negative dentry on a non-O_CREAT
open, and another client were to race in and create the file before we
issue our OPEN, ceph_fill_trace could end up calling d_splice_alias on
the dentry with the new inode with insufficient locks.
Cc: stable@vger.kernel.org
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ceph/file.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/ceph/file.c b/fs/ceph/file.c index d277f71abe0b..d2854cd2f4f5 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -462,6 +462,9 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry, err = ceph_security_init_secctx(dentry, mode, &as_ctx); if (err < 0) goto out_ctx; + } else if (!d_in_lookup(dentry)) { + /* If it's not being looked up, it's negative */ + return -ENOENT; } /* do the open */ |