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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dir.h
/******************************************************************************
*******************************************************************************
**
** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
** Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
**
** This copyrighted material is made available to anyone wishing to use,
** modify, copy, or redistribute it subject to the terms and conditions
** of the GNU General Public License v.2.
**
*******************************************************************************
******************************************************************************/
#ifndef __DIR_DOT_H__
#define __DIR_DOT_H__
int dlm_dir_nodeid(struct dlm_rsb *rsb);
int dlm_hash2nodeid(struct dlm_ls *ls, uint32_t hash);
void dlm_dir_remove_entry(struct dlm_ls *ls, int nodeid, char *name, int len);
void dlm_dir_clear(struct dlm_ls *ls);
void dlm_clear_free_entries(struct dlm_ls *ls);
int dlm_recover_directory(struct dlm_ls *ls);
int dlm_dir_lookup(struct dlm_ls *ls, int nodeid, char *name, int namelen,
int *r_nodeid);
void dlm_copy_master_names(struct dlm_ls *ls, char *inbuf, int inlen,
char *outbuf, int outlen, int nodeid);
#endif /* __DIR_DOT_H__ */
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