Revision e34a314c5e49fe6b763568f6576b19f1299c33c2 authored by Dave Chinner on 27 January 2011, 01:13:35 UTC, committed by Alex Elder on 28 January 2011, 15:01:33 UTC
After test 139, kmemleak shows:

unreferenced object 0xffff880078b405d8 (size 400):
  comm "xfs_io", pid 4904, jiffies 4294909383 (age 1186.728s)
  hex dump (first 32 bytes):
    60 c1 17 79 00 88 ff ff 60 c1 17 79 00 88 ff ff  `..y....`..y....
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<ffffffff81afb04d>] kmemleak_alloc+0x2d/0x60
    [<ffffffff8115c6cf>] kmem_cache_alloc+0x13f/0x2b0
    [<ffffffff814aaa97>] kmem_zone_alloc+0x77/0xf0
    [<ffffffff814aab2e>] kmem_zone_zalloc+0x1e/0x50
    [<ffffffff8147cd6b>] xfs_efi_init+0x4b/0xb0
    [<ffffffff814a4ee8>] xfs_trans_get_efi+0x58/0x90
    [<ffffffff81455fab>] xfs_bmap_finish+0x8b/0x1d0
    [<ffffffff814851b4>] xfs_itruncate_finish+0x2c4/0x5d0
    [<ffffffff814a970f>] xfs_setattr+0x8df/0xa70
    [<ffffffff814b5c7b>] xfs_vn_setattr+0x1b/0x20
    [<ffffffff8117dc00>] notify_change+0x170/0x2e0
    [<ffffffff81163bf6>] do_truncate+0x66/0xa0
    [<ffffffff81163d0b>] sys_ftruncate+0xdb/0xe0
    [<ffffffff8103a002>] system_call_fastpath+0x16/0x1b
    [<ffffffffffffffff>] 0xffffffffffffffff

The cause of the leak is that the "remove" parameter of IOP_UNPIN()
is never set when a CIL push is aborted. This means that the EFI
item is never freed if it was in the push being cancelled. The
problem is specific to delayed logging, but has uncovered a couple
of problems with the handling of IOP_UNPIN(remove).

Firstly, we cannot safely call xfs_trans_del_item() from IOP_UNPIN()
in the CIL commit failure path or the iclog write failure path
because for delayed loging we have no transaction context. Hence we
must only call xfs_trans_del_item() if the log item being unpinned
has an active log item descriptor.

Secondly, xfs_trans_uncommit() does not handle log item descriptor
freeing during the traversal of log items on a transaction. It can
reference a freed log item descriptor when unpinning an EFI item.
Hence it needs to use a safe list traversal method to allow items to
be removed from the transaction during IOP_UNPIN().

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Alex Elder <aelder@sgi.com>
1 parent 7db37c5
Raw File
xfs_btree_trace.h
/*
 * Copyright (c) 2008 Silicon Graphics, Inc.
 * 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.
 *
 * This program is distributed in the hope that it would 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 the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#ifndef __XFS_BTREE_TRACE_H__
#define	__XFS_BTREE_TRACE_H__

struct xfs_btree_cur;
struct xfs_buf;


/*
 * Trace hooks.
 * i,j = integer (32 bit)
 * b = btree block buffer (xfs_buf_t)
 * p = btree ptr
 * r = btree record
 * k = btree key
 */

#ifdef XFS_BTREE_TRACE

/*
 * Trace buffer entry types.
 */
#define XFS_BTREE_KTRACE_ARGBI   1
#define XFS_BTREE_KTRACE_ARGBII  2
#define XFS_BTREE_KTRACE_ARGFFFI 3
#define XFS_BTREE_KTRACE_ARGI    4
#define XFS_BTREE_KTRACE_ARGIPK  5
#define XFS_BTREE_KTRACE_ARGIPR  6
#define XFS_BTREE_KTRACE_ARGIK   7
#define XFS_BTREE_KTRACE_ARGR	 8
#define XFS_BTREE_KTRACE_CUR     9

/*
 * Sub-types for cursor traces.
 */
#define XBT_ARGS	0
#define XBT_ENTRY	1
#define XBT_ERROR	2
#define XBT_EXIT	3

void xfs_btree_trace_argbi(const char *, struct xfs_btree_cur *,
		struct xfs_buf *, int, int);
void xfs_btree_trace_argbii(const char *, struct xfs_btree_cur *,
		struct xfs_buf *, int, int, int);
void xfs_btree_trace_argi(const char *, struct xfs_btree_cur *, int, int);
void xfs_btree_trace_argipk(const char *, struct xfs_btree_cur *, int,
		union xfs_btree_ptr, union xfs_btree_key *, int);
void xfs_btree_trace_argipr(const char *, struct xfs_btree_cur *, int,
		union xfs_btree_ptr, union xfs_btree_rec *, int);
void xfs_btree_trace_argik(const char *, struct xfs_btree_cur *, int,
		union xfs_btree_key *, int);
void xfs_btree_trace_argr(const char *, struct xfs_btree_cur *,
		union xfs_btree_rec *, int);
void xfs_btree_trace_cursor(const char *, struct xfs_btree_cur *, int, int);

#define	XFS_BTREE_TRACE_ARGBI(c, b, i)	\
	xfs_btree_trace_argbi(__func__, c, b, i, __LINE__)
#define	XFS_BTREE_TRACE_ARGBII(c, b, i, j)	\
	xfs_btree_trace_argbii(__func__, c, b, i, j, __LINE__)
#define	XFS_BTREE_TRACE_ARGI(c, i)	\
	xfs_btree_trace_argi(__func__, c, i, __LINE__)
#define	XFS_BTREE_TRACE_ARGIPK(c, i, p, k)	\
	xfs_btree_trace_argipk(__func__, c, i, p, k, __LINE__)
#define	XFS_BTREE_TRACE_ARGIPR(c, i, p, r)	\
	xfs_btree_trace_argipr(__func__, c, i, p, r, __LINE__)
#define	XFS_BTREE_TRACE_ARGIK(c, i, k)	\
	xfs_btree_trace_argik(__func__, c, i, k, __LINE__)
#define XFS_BTREE_TRACE_ARGR(c, r)	\
	xfs_btree_trace_argr(__func__, c, r, __LINE__)
#define	XFS_BTREE_TRACE_CURSOR(c, t)	\
	xfs_btree_trace_cursor(__func__, c, t, __LINE__)
#else
#define	XFS_BTREE_TRACE_ARGBI(c, b, i)
#define	XFS_BTREE_TRACE_ARGBII(c, b, i, j)
#define	XFS_BTREE_TRACE_ARGI(c, i)
#define	XFS_BTREE_TRACE_ARGIPK(c, i, p, s)
#define	XFS_BTREE_TRACE_ARGIPR(c, i, p, r)
#define	XFS_BTREE_TRACE_ARGIK(c, i, k)
#define XFS_BTREE_TRACE_ARGR(c, r)
#define	XFS_BTREE_TRACE_CURSOR(c, t)
#endif	/* XFS_BTREE_TRACE */

#endif /* __XFS_BTREE_TRACE_H__ */
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