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Revision 84811412464d66fcf73661a279aa1d7985166495 authored by Prashant Malani on 20 November 2019, 19:40:21 UTC, committed by David S. Miller on 20 November 2019, 20:48:13 UTC 
r8152: Re-order napi_disable in rtl8152_close
 
Both rtl_work_func_t() and rtl8152_close() call napi_disable().
Since the two calls aren't protected by a lock, if the close
function starts executing before the work function, we can get into a
situation where the napi_disable() function is called twice in
succession (first by rtl8152_close(), then by set_carrier()).

In such a situation, the second call would loop indefinitely, since
rtl8152_close() doesn't call napi_enable() to clear the NAPI_STATE_SCHED
bit.

The rtl8152_close() function in turn issues a
cancel_delayed_work_sync(), and so it would wait indefinitely for the
rtl_work_func_t() to complete. Since rtl8152_close() is called by a
process holding rtnl_lock() which is requested by other processes, this
eventually leads to a system deadlock and crash.

Re-order the napi_disable() call to occur after the work function
disabling and urb cancellation calls are issued.

Change-Id: I6ef0b703fc214998a037a68f722f784e1d07815e
Reported-by: http://crbug.com/1017928
Signed-off-by: Prashant Malani <pmalani@chromium.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent b172845
Raw File
uptodate.h 
/* SPDX-License-Identifier: GPL-2.0-or-later */
/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * uptodate.h
 *
 * Cluster uptodate tracking
 *
 * Copyright (C) 2002, 2004, 2005 Oracle.  All rights reserved.
 */

#ifndef OCFS2_UPTODATE_H
#define OCFS2_UPTODATE_H

/*
 * The caching code relies on locking provided by the user of
 * struct ocfs2_caching_info.  These operations connect that up.
 */
struct ocfs2_caching_operations {
	/*
	 * A u64 representing the owning structure.  Usually this
	 * is the block number (i_blkno or whatnot).  This is used so
	 * that caching log messages can identify the owning structure.
	 */
	u64	(*co_owner)(struct ocfs2_caching_info *ci);

	/* The superblock is needed during I/O. */
	struct super_block *(*co_get_super)(struct ocfs2_caching_info *ci);
	/*
	 * Lock and unlock the caching data.  These will not sleep, and
	 * should probably be spinlocks.
	 */
	void	(*co_cache_lock)(struct ocfs2_caching_info *ci);
	void	(*co_cache_unlock)(struct ocfs2_caching_info *ci);

	/*
	 * Lock and unlock for disk I/O.  These will sleep, and should
	 * be mutexes.
	 */
	void	(*co_io_lock)(struct ocfs2_caching_info *ci);
	void	(*co_io_unlock)(struct ocfs2_caching_info *ci);
};

int __init init_ocfs2_uptodate_cache(void);
void exit_ocfs2_uptodate_cache(void);

void ocfs2_metadata_cache_init(struct ocfs2_caching_info *ci,
			       const struct ocfs2_caching_operations *ops);
void ocfs2_metadata_cache_purge(struct ocfs2_caching_info *ci);
void ocfs2_metadata_cache_exit(struct ocfs2_caching_info *ci);

u64 ocfs2_metadata_cache_owner(struct ocfs2_caching_info *ci);
void ocfs2_metadata_cache_io_lock(struct ocfs2_caching_info *ci);
void ocfs2_metadata_cache_io_unlock(struct ocfs2_caching_info *ci);

int ocfs2_buffer_uptodate(struct ocfs2_caching_info *ci,
			  struct buffer_head *bh);
void ocfs2_set_buffer_uptodate(struct ocfs2_caching_info *ci,
			       struct buffer_head *bh);
void ocfs2_set_new_buffer_uptodate(struct ocfs2_caching_info *ci,
				   struct buffer_head *bh);
void ocfs2_remove_from_cache(struct ocfs2_caching_info *ci,
			     struct buffer_head *bh);
void ocfs2_remove_xattr_clusters_from_cache(struct ocfs2_caching_info *ci,
					    sector_t block,
					    u32 c_len);
int ocfs2_buffer_read_ahead(struct ocfs2_caching_info *ci,
			    struct buffer_head *bh);

#endif /* OCFS2_UPTODATE_H */
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