If we are dropping last inode reference from downconvert thread, we will end up calling ocfs2_mark_lockres_freeing() which can block if the lock we are freeing is queued thus creating an A-A deadlock. Luckily, since we are the downconvert thread, we can immediately dequeue the lock and thus avoid waiting in this case. Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Reviewed-by: Srinivas Eeda <srinivas.eeda@oracle.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
		
			
				
	
	
		
			173 lines
		
	
	
	
		
			5.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			173 lines
		
	
	
	
		
			5.8 KiB
			
		
	
	
	
		
			C
		
	
	
	
	
	
/* -*- mode: c; c-basic-offset: 8; -*-
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 * vim: noexpandtab sw=8 ts=8 sts=0:
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 *
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 * dlmglue.h
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 *
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 * description here
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 *
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 * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
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 *
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 * This program is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU General Public
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 * License as published by the Free Software Foundation; either
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 * version 2 of the License, or (at your option) any later version.
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 *
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 * This program is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * General Public License for more details.
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 *
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 * You should have received a copy of the GNU General Public
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 * License along with this program; if not, write to the
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 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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 * Boston, MA 021110-1307, USA.
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 */
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#ifndef DLMGLUE_H
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#define DLMGLUE_H
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#include "dcache.h"
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#define OCFS2_LVB_VERSION 5
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struct ocfs2_meta_lvb {
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	__u8         lvb_version;
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	__u8         lvb_reserved0;
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	__be16       lvb_idynfeatures;
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	__be32       lvb_iclusters;
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	__be32       lvb_iuid;
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	__be32       lvb_igid;
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	__be64       lvb_iatime_packed;
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	__be64       lvb_ictime_packed;
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	__be64       lvb_imtime_packed;
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	__be64       lvb_isize;
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	__be16       lvb_imode;
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	__be16       lvb_inlink;
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	__be32       lvb_iattr;
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	__be32       lvb_igeneration;
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	__be32       lvb_reserved2;
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};
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#define OCFS2_QINFO_LVB_VERSION 1
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struct ocfs2_qinfo_lvb {
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	__u8	lvb_version;
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	__u8	lvb_reserved[3];
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	__be32	lvb_bgrace;
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	__be32	lvb_igrace;
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	__be32	lvb_syncms;
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	__be32	lvb_blocks;
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	__be32	lvb_free_blk;
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	__be32	lvb_free_entry;
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};
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#define OCFS2_ORPHAN_LVB_VERSION 1
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struct ocfs2_orphan_scan_lvb {
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	__u8	lvb_version;
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	__u8	lvb_reserved[3];
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	__be32	lvb_os_seqno;
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};
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/* ocfs2_inode_lock_full() 'arg_flags' flags */
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/* don't wait on recovery. */
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#define OCFS2_META_LOCK_RECOVERY	(0x01)
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/* Instruct the dlm not to queue ourselves on the other node. */
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#define OCFS2_META_LOCK_NOQUEUE		(0x02)
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/* don't block waiting for the downconvert thread, instead return -EAGAIN */
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#define OCFS2_LOCK_NONBLOCK		(0x04)
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/* Locking subclasses of inode cluster lock */
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enum {
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	OI_LS_NORMAL = 0,
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	OI_LS_PARENT,
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	OI_LS_RENAME1,
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	OI_LS_RENAME2,
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	OI_LS_REFLINK_TARGET,
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};
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int ocfs2_dlm_init(struct ocfs2_super *osb);
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void ocfs2_dlm_shutdown(struct ocfs2_super *osb, int hangup_pending);
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void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res);
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void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
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			       enum ocfs2_lock_type type,
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			       unsigned int generation,
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			       struct inode *inode);
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void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl,
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				u64 parent, struct inode *inode);
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struct ocfs2_file_private;
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void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
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			      struct ocfs2_file_private *fp);
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struct ocfs2_mem_dqinfo;
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void ocfs2_qinfo_lock_res_init(struct ocfs2_lock_res *lockres,
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                               struct ocfs2_mem_dqinfo *info);
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void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres,
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				  struct ocfs2_super *osb, u64 ref_blkno,
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				  unsigned int generation);
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void ocfs2_lock_res_free(struct ocfs2_lock_res *res);
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int ocfs2_create_new_inode_locks(struct inode *inode);
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int ocfs2_drop_inode_locks(struct inode *inode);
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int ocfs2_rw_lock(struct inode *inode, int write);
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void ocfs2_rw_unlock(struct inode *inode, int write);
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int ocfs2_open_lock(struct inode *inode);
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int ocfs2_try_open_lock(struct inode *inode, int write);
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void ocfs2_open_unlock(struct inode *inode);
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int ocfs2_inode_lock_atime(struct inode *inode,
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			  struct vfsmount *vfsmnt,
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			  int *level);
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int ocfs2_inode_lock_full_nested(struct inode *inode,
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			 struct buffer_head **ret_bh,
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			 int ex,
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			 int arg_flags,
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			 int subclass);
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int ocfs2_inode_lock_with_page(struct inode *inode,
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			      struct buffer_head **ret_bh,
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			      int ex,
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			      struct page *page);
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/* Variants without special locking class or flags */
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#define ocfs2_inode_lock_full(i, r, e, f)\
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		ocfs2_inode_lock_full_nested(i, r, e, f, OI_LS_NORMAL)
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#define ocfs2_inode_lock_nested(i, b, e, s)\
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		ocfs2_inode_lock_full_nested(i, b, e, 0, s)
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/* 99% of the time we don't want to supply any additional flags --
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 * those are for very specific cases only. */
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#define ocfs2_inode_lock(i, b, e) ocfs2_inode_lock_full_nested(i, b, e, 0, OI_LS_NORMAL)
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void ocfs2_inode_unlock(struct inode *inode,
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		       int ex);
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int ocfs2_super_lock(struct ocfs2_super *osb,
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		     int ex);
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void ocfs2_super_unlock(struct ocfs2_super *osb,
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			int ex);
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int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno);
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void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno);
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int ocfs2_rename_lock(struct ocfs2_super *osb);
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void ocfs2_rename_unlock(struct ocfs2_super *osb);
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int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex);
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void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex);
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int ocfs2_dentry_lock(struct dentry *dentry, int ex);
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void ocfs2_dentry_unlock(struct dentry *dentry, int ex);
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int ocfs2_file_lock(struct file *file, int ex, int trylock);
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void ocfs2_file_unlock(struct file *file);
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int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex);
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void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex);
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struct ocfs2_refcount_tree;
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int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex);
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void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex);
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void ocfs2_mark_lockres_freeing(struct ocfs2_super *osb,
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				struct ocfs2_lock_res *lockres);
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void ocfs2_simple_drop_lockres(struct ocfs2_super *osb,
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			       struct ocfs2_lock_res *lockres);
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/* for the downconvert thread */
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void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb);
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struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void);
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void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug);
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/* To set the locking protocol on module initialization */
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void ocfs2_set_locking_protocol(void);
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#endif	/* DLMGLUE_H */
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