From 5e64b0d9e86ffff8b299556341d85319117539e9 Mon Sep 17 00:00:00 2001 From: Tao Ma Date: Tue, 7 Sep 2010 13:30:05 +0800 Subject: ocfs2/lockdep: Move ip_xattr_sem out of ocfs2_xattr_get_nolock. As the name shows, we shouldn't have any lock in ocfs2_xattr_get_nolock. so lift ip_xattr_sem to the caller. This should be safe for us since the only 2 callers are: 1. ocfs2_xattr_get which will lock the resources. 2. ocfs2_mknod which don't need this locking. And this also resolves the following lockdep warning. ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.35+ #5 ------------------------------------------------------- reflink/30027 is trying to acquire lock: (&oi->ip_alloc_sem){+.+.+.}, at: [] ocfs2_reflink_ioctl+0x69a/0x1226 [ocfs2] but task is already holding lock: (&oi->ip_xattr_sem){++++..}, at: [] ocfs2_reflink_ioctl+0x68b/0x1226 [ocfs2] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&oi->ip_xattr_sem){++++..}: [] __lock_acquire+0x79a/0x7f1 [] lock_acquire+0xc6/0xed [] down_read+0x34/0x47 [] ocfs2_xattr_get_nolock+0xa0/0x4e6 [ocfs2] [] ocfs2_get_acl_nolock+0x5c/0x132 [ocfs2] [] ocfs2_init_acl+0x60/0x243 [ocfs2] [] ocfs2_mknod+0xae8/0xfea [ocfs2] [] ocfs2_create+0x9d/0x105 [ocfs2] [] vfs_create+0x9b/0xf4 [] do_last+0x2fd/0x5be [] do_filp_open+0x1fb/0x572 [] do_sys_open+0x5a/0xe7 [] sys_open+0x1b/0x1d [] system_call_fastpath+0x16/0x1b -> #2 (jbd2_handle){+.+...}: [] __lock_acquire+0x79a/0x7f1 [] lock_acquire+0xc6/0xed [] start_this_handle+0x4a3/0x4bc [jbd2] [] jbd2__journal_start+0xba/0xee [jbd2] [] jbd2_journal_start+0xe/0x10 [jbd2] [] ocfs2_start_trans+0xb7/0x19b [ocfs2] [] ocfs2_mknod+0x73e/0xfea [ocfs2] [] ocfs2_create+0x9d/0x105 [ocfs2] [] vfs_create+0x9b/0xf4 [] do_last+0x2fd/0x5be [] do_filp_open+0x1fb/0x572 [] do_sys_open+0x5a/0xe7 [] sys_open+0x1b/0x1d [] system_call_fastpath+0x16/0x1b -> #1 (&journal->j_trans_barrier){.+.+..}: [] __lock_acquire+0x79a/0x7f1 [] lock_release_non_nested+0x1e5/0x24b [] lock_release+0x158/0x17a [] __mutex_unlock_slowpath+0xbf/0x11b [] mutex_unlock+0x9/0xb [] ocfs2_free_ac_resource+0x31/0x67 [ocfs2] [] ocfs2_free_alloc_context+0x11/0x1d [ocfs2] [] ocfs2_write_begin_nolock+0x141e/0x159b [ocfs2] [] ocfs2_write_begin+0x11e/0x1e7 [ocfs2] [] generic_file_buffered_write+0x10c/0x210 [] ocfs2_file_aio_write+0x4cc/0x6d3 [ocfs2] [] do_sync_write+0xc2/0x106 [] vfs_write+0xae/0x131 [] sys_write+0x47/0x6f [] system_call_fastpath+0x16/0x1b -> #0 (&oi->ip_alloc_sem){+.+.+.}: [] validate_chain+0x727/0xd68 [] __lock_acquire+0x79a/0x7f1 [] lock_acquire+0xc6/0xed [] down_write+0x31/0x52 [] ocfs2_reflink_ioctl+0x69a/0x1226 [ocfs2] [] ocfs2_ioctl+0x61a/0x656 [ocfs2] [] vfs_ioctl+0x2a/0x9d [] do_vfs_ioctl+0x45d/0x4ae [] sys_ioctl+0x57/0x7a [] system_call_fastpath+0x16/0x1b Signed-off-by: Tao Ma Signed-off-by: Joel Becker --- fs/ocfs2/xattr.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs') diff --git a/fs/ocfs2/xattr.c b/fs/ocfs2/xattr.c index d03469f61801..06fa5e77c40e 100644 --- a/fs/ocfs2/xattr.c +++ b/fs/ocfs2/xattr.c @@ -1286,13 +1286,11 @@ int ocfs2_xattr_get_nolock(struct inode *inode, xis.inode_bh = xbs.inode_bh = di_bh; di = (struct ocfs2_dinode *)di_bh->b_data; - down_read(&oi->ip_xattr_sem); ret = ocfs2_xattr_ibody_get(inode, name_index, name, buffer, buffer_size, &xis); if (ret == -ENODATA && di->i_xattr_loc) ret = ocfs2_xattr_block_get(inode, name_index, name, buffer, buffer_size, &xbs); - up_read(&oi->ip_xattr_sem); return ret; } @@ -1316,8 +1314,10 @@ static int ocfs2_xattr_get(struct inode *inode, mlog_errno(ret); return ret; } + down_read(&OCFS2_I(inode)->ip_xattr_sem); ret = ocfs2_xattr_get_nolock(inode, di_bh, name_index, name, buffer, buffer_size); + up_read(&OCFS2_I(inode)->ip_xattr_sem); ocfs2_inode_unlock(inode, 0); -- cgit v1.2.3