ceph: fix sleeping function called from invalid context.

[ 1121.231883] BUG: sleeping function called from invalid context at kernel/rwsem.c:20
[ 1121.231935] in_atomic(): 1, irqs_disabled(): 0, pid: 9831, name: mv
[ 1121.231971] 1 lock held by mv/9831:
[ 1121.231973]  #0:  (&(&ci->i_ceph_lock)->rlock){+.+...},at:[<ffffffffa02bbd38>] ceph_getxattr+0x58/0x1d0 [ceph]
[ 1121.231998] CPU: 3 PID: 9831 Comm: mv Not tainted 3.10.0-rc6+ #215
[ 1121.232000] Hardware name: To Be Filled By O.E.M. To Be Filled By
O.E.M./To be filled by O.E.M., BIOS 080015  11/09/2011
[ 1121.232027]  ffff88006d355a80 ffff880092f69ce0 ffffffff8168348c ffff880092f69cf8
[ 1121.232045]  ffffffff81070435 ffff88006d355a20 ffff880092f69d20 ffffffff816899ba
[ 1121.232052]  0000000300000004 ffff8800b76911d0 ffff88006d355a20 ffff880092f69d68
[ 1121.232056] Call Trace:
[ 1121.232062]  [<ffffffff8168348c>] dump_stack+0x19/0x1b
[ 1121.232067]  [<ffffffff81070435>] __might_sleep+0xe5/0x110
[ 1121.232071]  [<ffffffff816899ba>] down_read+0x2a/0x98
[ 1121.232080]  [<ffffffffa02baf70>] ceph_vxattrcb_layout+0x60/0xf0 [ceph]
[ 1121.232088]  [<ffffffffa02bbd7f>] ceph_getxattr+0x9f/0x1d0 [ceph]
[ 1121.232093]  [<ffffffff81188d28>] vfs_getxattr+0xa8/0xd0
[ 1121.232097]  [<ffffffff8118900b>] getxattr+0xab/0x1c0
[ 1121.232100]  [<ffffffff811704f2>] ? final_putname+0x22/0x50
[ 1121.232104]  [<ffffffff81155f80>] ? kmem_cache_free+0xb0/0x260
[ 1121.232107]  [<ffffffff811704f2>] ? final_putname+0x22/0x50
[ 1121.232110]  [<ffffffff8109e63d>] ? trace_hardirqs_on+0xd/0x10
[ 1121.232114]  [<ffffffff816957a7>] ? sysret_check+0x1b/0x56
[ 1121.232120]  [<ffffffff81189c9c>] SyS_fgetxattr+0x6c/0xc0
[ 1121.232125]  [<ffffffff81695782>] system_call_fastpath+0x16/0x1b
[ 1121.232129] BUG: scheduling while atomic: mv/9831/0x10000002
[ 1121.232154] 1 lock held by mv/9831:
[ 1121.232156]  #0:  (&(&ci->i_ceph_lock)->rlock){+.+...}, at:
[<ffffffffa02bbd38>] ceph_getxattr+0x58/0x1d0 [ceph]

I think move the ci->i_ceph_lock down is safe because we can't free
ceph_inode_info at there.

CC: stable@vger.kernel.org  # 3.8+
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Reviewed-by: Sage Weil <sage@inktank.com>

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 9b6b2b6..be661d8 100644 (file)
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -675,17 +675,18 @@ ssize_t ceph_getxattr(struct dentry *dentry, const char *name, void *value,
        if (!ceph_is_valid_xattr(name))
                return -ENODATA;
 
-       spin_lock(&ci->i_ceph_lock);
-       dout("getxattr %p ver=%lld index_ver=%lld\n", inode,
-            ci->i_xattrs.version, ci->i_xattrs.index_version);
 
        /* let's see if a virtual xattr was requested */
        vxattr = ceph_match_vxattr(inode, name);
        if (vxattr && !(vxattr->exists_cb && !vxattr->exists_cb(ci))) {
                err = vxattr->getxattr_cb(ci, value, size);
-               goto out;
+               return err;
        }
 
+       spin_lock(&ci->i_ceph_lock);
+       dout("getxattr %p ver=%lld index_ver=%lld\n", inode,
+            ci->i_xattrs.version, ci->i_xattrs.index_version);
+
        if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1) &&
            (ci->i_xattrs.index_version >= ci->i_xattrs.version)) {
                goto get_xattr;