Revision 619b0488038224391e64fa03854651ca0f5efe56 authored by Raistlin on 26 June 2008, 16:54:09 UTC, committed by Ingo Molnar on 01 July 2008, 06:23:24 UTC
Here it is another little Oops we found while configuring invalid values
via cgroups:

echo 0 > /dev/cgroups/0/cpu.rt_period_us
or
echo 4294967296 > /dev/cgroups/0/cpu.rt_period_us

[  205.509825] divide error: 0000 [#1]
[  205.510151] Modules linked in:
[  205.510151]
[  205.510151] Pid: 2339, comm: bash Not tainted (2.6.26-rc8 #33)
[  205.510151] EIP: 0060:[<c030c6ef>] EFLAGS: 00000293 CPU: 0
[  205.510151] EIP is at div64_u64+0x5f/0x70
[  205.510151] EAX: 0000389f EBX: 00000000 ECX: 00000000 EDX: 00000000
[  205.510151] ESI: d9800000 EDI: 00000000 EBP: c6cede60 ESP: c6cede50
[  205.510151]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 0068
[  205.510151] Process bash (pid: 2339, ti=c6cec000 task=c79be370 task.ti=c6cec000)
[  205.510151] Stack: d9800000 0000389f c05971a0 d9800000 c6cedeb4 c0214dbd 00000000 00000000
[  205.510151]        c6cede88 c0242bd8 c05377c0 c7a41b40 00000000 00000000 00000000 c05971a0
[  205.510151]        c780ed20 c7508494 c7a41b40 00000000 00000002 c6cedebc c05971a0 ffffffea
[  205.510151] Call Trace:
[  205.510151]  [<c0214dbd>] ? __rt_schedulable+0x1cd/0x240
[  205.510151]  [<c0242bd8>] ? cgroup_file_open+0x18/0xe0
[  205.510151]  [<c0214fe4>] ? tg_set_bandwidth+0xa4/0xf0
[  205.510151]  [<c0215066>] ? sched_group_set_rt_period+0x36/0x50
[  205.510151]  [<c021508e>] ? cpu_rt_period_write_uint+0xe/0x10
[  205.510151]  [<c0242dc5>] ? cgroup_file_write+0x125/0x160
[  205.510151]  [<c0232c15>] ? hrtimer_interrupt+0x155/0x190
[  205.510151]  [<c02f047f>] ? security_file_permission+0xf/0x20
[  205.510151]  [<c0277ad8>] ? rw_verify_area+0x48/0xc0
[  205.510151]  [<c0283744>] ? dupfd+0x104/0x130
[  205.510151]  [<c027838c>] ? vfs_write+0x9c/0x160
[  205.510151]  [<c0242ca0>] ? cgroup_file_write+0x0/0x160
[  205.510151]  [<c027850d>] ? sys_write+0x3d/0x70
[  205.510151]  [<c0203019>] ? sysenter_past_esp+0x6a/0x91
[  205.510151]  =======================
[  205.510151] Code: 0f 45 de 31 f6 0f ad d0 d3 ea f6 c1 20 0f 45 c2 0f 45 d6 89 45 f0 89 55 f4 8b 55 f4 31 c9 8b 45 f0 39 d3 89 c6 77 08 89 d0 31 d2 <f7> f3 89 c1 83 c4 08 89 f0 f7 f3 89 ca 5b 5e 5d c3 55 89 e5 56
[  205.510151] EIP: [<c030c6ef>] div64_u64+0x5f/0x70 SS:ESP 0068:c6cede50

The attached patch solves the issue for me.

I'm checking as soon as possible for the period not being zero since, if
it is, going ahead is useless. This way we also save a mutex_lock() and
a read_lock() wrt doing it inside tg_set_bandwidth() or
__rt_schedulable().

Signed-off-by: Dario Faggioli <raistlin@linux.it>
Signed-off-by: Michael Trimarchi <trimarchimichael@yahoo.it>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
1 parent 79c5379
Raw File
dir.h
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * dir.h
 *
 * Function prototypes
 *
 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#ifndef OCFS2_DIR_H
#define OCFS2_DIR_H

struct buffer_head *ocfs2_find_entry(const char *name,
				     int namelen,
				     struct inode *dir,
				     struct ocfs2_dir_entry **res_dir);
int ocfs2_delete_entry(handle_t *handle,
		       struct inode *dir,
		       struct ocfs2_dir_entry *de_del,
		       struct buffer_head *bh);
int __ocfs2_add_entry(handle_t *handle,
		      struct inode *dir,
		      const char *name, int namelen,
		      struct inode *inode, u64 blkno,
		      struct buffer_head *parent_fe_bh,
		      struct buffer_head *insert_bh);
static inline int ocfs2_add_entry(handle_t *handle,
				  struct dentry *dentry,
				  struct inode *inode, u64 blkno,
				  struct buffer_head *parent_fe_bh,
				  struct buffer_head *insert_bh)
{
	return __ocfs2_add_entry(handle, dentry->d_parent->d_inode,
				 dentry->d_name.name, dentry->d_name.len,
				 inode, blkno, parent_fe_bh, insert_bh);
}
int ocfs2_update_entry(struct inode *dir, handle_t *handle,
		       struct buffer_head *de_bh, struct ocfs2_dir_entry *de,
		       struct inode *new_entry_inode);

int ocfs2_check_dir_for_entry(struct inode *dir,
			      const char *name,
			      int namelen);
int ocfs2_empty_dir(struct inode *inode);
int ocfs2_find_files_on_disk(const char *name,
			     int namelen,
			     u64 *blkno,
			     struct inode *inode,
			     struct buffer_head **dirent_bh,
			     struct ocfs2_dir_entry **dirent);
int ocfs2_lookup_ino_from_name(struct inode *dir, const char *name,
			       int namelen, u64 *blkno);
int ocfs2_readdir(struct file *filp, void *dirent, filldir_t filldir);
int ocfs2_dir_foreach(struct inode *inode, loff_t *f_pos, void *priv,
		      filldir_t filldir);
int ocfs2_prepare_dir_for_insert(struct ocfs2_super *osb,
				 struct inode *dir,
				 struct buffer_head *parent_fe_bh,
				 const char *name,
				 int namelen,
				 struct buffer_head **ret_de_bh);
struct ocfs2_alloc_context;
int ocfs2_fill_new_dir(struct ocfs2_super *osb,
		       handle_t *handle,
		       struct inode *parent,
		       struct inode *inode,
		       struct buffer_head *fe_bh,
		       struct ocfs2_alloc_context *data_ac);

#endif /* OCFS2_DIR_H */
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