Revision 8cf66504210d308a35cca35fe9c310b1241f9fa7 authored by Qian Cai on 11 July 2019, 16:17:45 UTC, committed by Linus Torvalds on 21 July 2019, 16:57:13 UTC
The commit b3aa14f02254 ("iommu: remove the mapping_error dma_map_ops
method") incorrectly changed the checking from dma_ops_alloc_iova() in
map_sg() causes a crash under memory pressure as dma_ops_alloc_iova()
never return DMA_MAPPING_ERROR on failure but 0, so the error handling
is all wrong.

   kernel BUG at drivers/iommu/iova.c:801!
    Workqueue: kblockd blk_mq_run_work_fn
    RIP: 0010:iova_magazine_free_pfns+0x7d/0xc0
    Call Trace:
     free_cpu_cached_iovas+0xbd/0x150
     alloc_iova_fast+0x8c/0xba
     dma_ops_alloc_iova.isra.6+0x65/0xa0
     map_sg+0x8c/0x2a0
     scsi_dma_map+0xc6/0x160
     pqi_aio_submit_io+0x1f6/0x440 [smartpqi]
     pqi_scsi_queue_command+0x90c/0xdd0 [smartpqi]
     scsi_queue_rq+0x79c/0x1200
     blk_mq_dispatch_rq_list+0x4dc/0xb70
     blk_mq_sched_dispatch_requests+0x249/0x310
     __blk_mq_run_hw_queue+0x128/0x200
     blk_mq_run_work_fn+0x27/0x30
     process_one_work+0x522/0xa10
     worker_thread+0x63/0x5b0
     kthread+0x1d2/0x1f0
     ret_from_fork+0x22/0x40

Fixes: b3aa14f02254 ("iommu: remove the mapping_error dma_map_ops method")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 618381f
Raw File
xfs_itable.h
// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (c) 2000-2001 Silicon Graphics, Inc.  All Rights Reserved.
 */
#ifndef __XFS_ITABLE_H__
#define	__XFS_ITABLE_H__

/* In-memory representation of a userspace request for batch inode data. */
struct xfs_ibulk {
	struct xfs_mount	*mp;
	void __user		*ubuffer; /* user output buffer */
	xfs_ino_t		startino; /* start with this inode */
	unsigned int		icount;   /* number of elements in ubuffer */
	unsigned int		ocount;   /* number of records returned */
	unsigned int		flags;    /* see XFS_IBULK_FLAG_* */
};

/* Only iterate within the same AG as startino */
#define XFS_IBULK_SAME_AG	(XFS_IWALK_SAME_AG)

/* Return value that means we want to abort the walk. */
#define XFS_IBULK_ABORT		(XFS_IWALK_ABORT)

/*
 * Advance the user buffer pointer by one record of the given size.  If the
 * buffer is now full, return the appropriate error code.
 */
static inline int
xfs_ibulk_advance(
	struct xfs_ibulk	*breq,
	size_t			bytes)
{
	char __user		*b = breq->ubuffer;

	breq->ubuffer = b + bytes;
	breq->ocount++;
	return breq->ocount == breq->icount ? XFS_IBULK_ABORT : 0;
}

/*
 * Return stat information in bulk (by-inode) for the filesystem.
 */

typedef int (*bulkstat_one_fmt_pf)(struct xfs_ibulk *breq,
		const struct xfs_bulkstat *bstat);

int xfs_bulkstat_one(struct xfs_ibulk *breq, bulkstat_one_fmt_pf formatter);
int xfs_bulkstat(struct xfs_ibulk *breq, bulkstat_one_fmt_pf formatter);
void xfs_bulkstat_to_bstat(struct xfs_mount *mp, struct xfs_bstat *bs1,
		const struct xfs_bulkstat *bstat);

typedef int (*inumbers_fmt_pf)(struct xfs_ibulk *breq,
		const struct xfs_inumbers *igrp);

int xfs_inumbers(struct xfs_ibulk *breq, inumbers_fmt_pf formatter);
void xfs_inumbers_to_inogrp(struct xfs_inogrp *ig1,
		const struct xfs_inumbers *ig);

#endif	/* __XFS_ITABLE_H__ */
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