[PATCH V1] ceph: fix sleeping function called from invalid context.

From: majianpeng
Date: Wed Jun 19 2013 - 02:58:20 EST


[ 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.

Signed-off-by: Jianpeng Ma <majianpeng@xxxxxxxxx>
---
fs/ceph/xattr.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 9b6b2b6..be661d8 100644
--- 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;
--
1.8.3.rc1.44.gb387c77
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