https://github.com/torvalds/linux
Revision 914ee295af418e936ec20a08c1663eaabe4cd07a authored by Xin Zhong on 09 December 2010, 09:30:14 UTC, committed by Chris Mason on 10 December 2010, 21:29:10 UTC
This problem is found in meego testing: http://bugs.meego.com/show_bug.cgi?id=6672 A file in btrfs is mmaped and the mmaped buffer is passed to pwrite to write to the same page of the same file. In btrfs_file_aio_write(), the pages is locked by prepare_pages(). So when btrfs_copy_from_user() is called, page fault happens and the same page needs to be locked again in filemap_fault(). The fix is to move iov_iter_fault_in_readable() before prepage_pages() to make page fault happen before pages are locked. And also disable page fault in critical region in btrfs_copy_from_user(). Reviewed-by: Yan, Zheng<zheng.z.yan@intel.com> Signed-off-by: Zhong, Xin <xin.zhong@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
1 parent f106e82
Tip revision: 914ee295af418e936ec20a08c1663eaabe4cd07a authored by Xin Zhong on 09 December 2010, 09:30:14 UTC
Btrfs: pwrite blocked when writing from the mmaped buffer of the same page
Btrfs: pwrite blocked when writing from the mmaped buffer of the same page
Tip revision: 914ee29
vxfs_extern.h
/*
* Copyright (c) 2000-2001 Christoph Hellwig.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions, and the following disclaimer,
* without modification.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL").
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
*/
#ifndef _VXFS_EXTERN_H_
#define _VXFS_EXTERN_H_
/*
* Veritas filesystem driver - external prototypes.
*
* This file contains prototypes for all vxfs functions used
* outside their respective source files.
*/
struct kmem_cache;
struct super_block;
struct vxfs_inode_info;
struct inode;
/* vxfs_bmap.c */
extern daddr_t vxfs_bmap1(struct inode *, long);
/* vxfs_fshead.c */
extern int vxfs_read_fshead(struct super_block *);
/* vxfs_immed.c */
extern const struct inode_operations vxfs_immed_symlink_iops;
/* vxfs_inode.c */
extern const struct address_space_operations vxfs_immed_aops;
extern struct kmem_cache *vxfs_inode_cachep;
extern void vxfs_dumpi(struct vxfs_inode_info *, ino_t);
extern struct inode * vxfs_get_fake_inode(struct super_block *,
struct vxfs_inode_info *);
extern void vxfs_put_fake_inode(struct inode *);
extern struct vxfs_inode_info * vxfs_blkiget(struct super_block *, u_long, ino_t);
extern struct vxfs_inode_info * vxfs_stiget(struct super_block *, ino_t);
extern struct inode * vxfs_iget(struct super_block *, ino_t);
extern void vxfs_evict_inode(struct inode *);
/* vxfs_lookup.c */
extern const struct inode_operations vxfs_dir_inode_ops;
extern const struct file_operations vxfs_dir_operations;
/* vxfs_olt.c */
extern int vxfs_read_olt(struct super_block *, u_long);
/* vxfs_subr.c */
extern const struct address_space_operations vxfs_aops;
extern struct page * vxfs_get_page(struct address_space *, u_long);
extern void vxfs_put_page(struct page *);
extern struct buffer_head * vxfs_bread(struct inode *, int);
#endif /* _VXFS_EXTERN_H_ */
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