| Message ID | 20191031204737.20310-1-jlayton@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] ceph: don't try to handle hashed dentries in non-O_CREAT atomic_open | expand |
diff --git a/fs/ceph/file.c b/fs/ceph/file.c index e9689e7bea08..bd77adb64bfd 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 */
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. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jeff Layton <jlayton@kernel.org> --- fs/ceph/file.c | 3 +++ 1 file changed, 3 insertions(+)