Revision 7fb5409df092589b86cc9412d926879cb572b7f0 authored by Jan Kara on 10 February 2008, 06:08:38 UTC, committed by Theodore Ts'o on 10 February 2008, 06:08:38 UTC
We cannot start transaction in ext4_direct_IO() and just let it last during the whole write because dio_get_page() acquires mmap_sem which ranks above transaction start (e.g. because we have dependency chain mmap_sem->PageLock->journal_start, or because we update atime while holding mmap_sem) and thus deadlocks could happen. We solve the problem by starting a transaction separately for each ext4_get_block() call. We *could* have a problem that we allocate a block and before its data are written out the machine crashes and thus we expose stale data. But that does not happen because for hole-filling generic code falls back to buffered writes and for file extension, we add inode to orphan list and thus in case of crash, journal replay will truncate inode back to the original size. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Mingming Cao <cmm@us.ibm.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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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_inode.c */
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_clear_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 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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