diff options
| author | Yan, Zheng <zyan@redhat.com> | 2016-03-07 10:34:50 +0800 |
|---|---|---|
| committer | Ilya Dryomov <idryomov@gmail.com> | 2016-03-25 18:51:55 +0100 |
| commit | 315f24088048a51eed341c53be66ea477a3c7d16 (patch) | |
| tree | b0947756198ee556f500e2b5dd001104fec003b8 /fs/ceph/file.c | |
| parent | 29dccfa5af388916e48a3edc5ac9dc8cc996d9b4 (diff) | |
ceph: fix security xattr deadlock
When security is enabled, security module can call filesystem's
getxattr/setxattr callbacks during d_instantiate(). For cephfs,
d_instantiate() is usually called by MDS' dispatch thread, while
handling MDS reply. If the MDS reply does not include xattrs and
corresponding caps, getxattr/setxattr need to send a new request
to MDS and waits for the reply. This makes MDS' dispatch sleep,
nobody handles later MDS replies.
The fix is make sure lookup/atomic_open reply include xattrs and
corresponding caps. So getxattr can be handled by cached xattrs.
This requires some modification to both MDS and request message.
(Client tells MDS what caps it wants; MDS encodes proper caps in
the reply)
Smack security module may call setxattr during d_instantiate().
Unlike getxattr, we can't force MDS to issue CEPH_CAP_XATTR_EXCL
to us. So just make setxattr return error when called by MDS'
dispatch thread.
Signed-off-by: Yan, Zheng <zyan@redhat.com>
Diffstat (limited to 'fs/ceph/file.c')
| -rw-r--r-- | fs/ceph/file.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/ceph/file.c b/fs/ceph/file.c index 389adacbc719..334a75170a3b 100644 --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -300,6 +300,7 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry, struct ceph_mds_request *req; struct dentry *dn; struct ceph_acls_info acls = {}; + int mask; int err; dout("atomic_open %p dentry %p '%pd' %s flags %d mode 0%o\n", @@ -335,6 +336,12 @@ int ceph_atomic_open(struct inode *dir, struct dentry *dentry, acls.pagelist = NULL; } } + + mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED; + if (ceph_security_xattr_wanted(dir)) + mask |= CEPH_CAP_XATTR_SHARED; + req->r_args.open.mask = cpu_to_le32(mask); + req->r_locked_dir = dir; /* caller holds dir->i_mutex */ err = ceph_mdsc_do_request(mdsc, (flags & (O_CREAT|O_TRUNC)) ? dir : NULL, |