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From: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
To: Elias Oltmanns <eo@nebensachen.de>
Subject: Re: [PATCH] IDE: Fix HDIO_DRIVE_RESET handling
Date: Tue, 24 Jun 2008 00:41:45 +0200
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       Randy Dunlap <randy.dunlap@oracle.com>
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On Monday 23 June 2008, Elias Oltmanns wrote:
> Currently, the code path executing an HDIO_DRIVE_RESET ioctl is broken
> in various ways.  Most importantly, it is treated as an out of band
> request in an illegal way which may very likely lead to system lock ups.
> Use the drive's request queue to avoid this problem (and fix a locking
> issue for free along the way).
> 
> Signed-off-by: Elias Oltmanns <eo@nebensachen.de>

[...]

> +		} else if (!rq->rq_disk && blk_special_request(rq))
> +			/*
> +			 * TODO: Once all ULDs have been modified to
> +			 * check for specific op codes rather than
> +			 * blindly accepting any special request, the
> +			 * echeck for ->rq_disk above may be replaced

'echeck' typo.

[...]

> +static inline void ide_complete_drive_reset(ide_drive_t *drive)
> +{
> +	struct request *rq = HWGROUP(drive)->rq;
> +
> +	if (rq && blk_special_request(rq) && rq->cmd[0] == REQ_DRIVE_RESET)

Shouldn't we be also checking for !rq->rq_disk here?

[ also HWGROUP() macro is on its way out ]

Otherwise OK.