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	Linux v4.20-rc5-86-gb72f711a4efa
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				| @ -1,99 +0,0 @@ | ||||
| From ffe81d45322cc3cb140f0db080a4727ea284661e Mon Sep 17 00:00:00 2001 | ||||
| From: Jens Axboe <axboe@kernel.dk> | ||||
| Date: Tue, 4 Dec 2018 20:06:48 -0700 | ||||
| Subject: [PATCH] blk-mq: fix corruption with direct issue | ||||
| 
 | ||||
| If we attempt a direct issue to a SCSI device, and it returns BUSY, then | ||||
| we queue the request up normally. However, the SCSI layer may have | ||||
| already setup SG tables etc for this particular command. If we later | ||||
| merge with this request, then the old tables are no longer valid. Once | ||||
| we issue the IO, we only read/write the original part of the request, | ||||
| not the new state of it. | ||||
| 
 | ||||
| This causes data corruption, and is most often noticed with the file | ||||
| system complaining about the just read data being invalid: | ||||
| 
 | ||||
| [  235.934465] EXT4-fs error (device sda1): ext4_iget:4831: inode #7142: comm dpkg-query: bad extra_isize 24937 (inode size 256) | ||||
| 
 | ||||
| because most of it is garbage... | ||||
| 
 | ||||
| This doesn't happen from the normal issue path, as we will simply defer | ||||
| the request to the hardware queue dispatch list if we fail. Once it's on | ||||
| the dispatch list, we never merge with it. | ||||
| 
 | ||||
| Fix this from the direct issue path by flagging the request as | ||||
| REQ_NOMERGE so we don't change the size of it before issue. | ||||
| 
 | ||||
| See also: | ||||
|   https://bugzilla.kernel.org/show_bug.cgi?id=201685 | ||||
| 
 | ||||
| Tested-by: Guenter Roeck <linux@roeck-us.net> | ||||
| Fixes: 6ce3dd6eec1 ("blk-mq: issue directly if hw queue isn't busy in case of 'none'") | ||||
| Cc: stable@vger.kernel.org | ||||
| Signed-off-by: Jens Axboe <axboe@kernel.dk> | ||||
| Signed-off-by: Jeremy Cline <jcline@redhat.com> | ||||
| ---
 | ||||
|  block/blk-mq.c | 26 +++++++++++++++++++++++++- | ||||
|  1 file changed, 25 insertions(+), 1 deletion(-) | ||||
| 
 | ||||
| diff --git a/block/blk-mq.c b/block/blk-mq.c
 | ||||
| index 3f91c6e5b17a..3262d83b9e07 100644
 | ||||
| --- a/block/blk-mq.c
 | ||||
| +++ b/block/blk-mq.c
 | ||||
| @@ -1715,6 +1715,15 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
 | ||||
|  		break; | ||||
|  	case BLK_STS_RESOURCE: | ||||
|  	case BLK_STS_DEV_RESOURCE: | ||||
| +		/*
 | ||||
| +		 * If direct dispatch fails, we cannot allow any merging on
 | ||||
| +		 * this IO. Drivers (like SCSI) may have set up permanent state
 | ||||
| +		 * for this request, like SG tables and mappings, and if we
 | ||||
| +		 * merge to it later on then we'll still only do IO to the
 | ||||
| +		 * original part.
 | ||||
| +		 */
 | ||||
| +		rq->cmd_flags |= REQ_NOMERGE;
 | ||||
| +
 | ||||
|  		blk_mq_update_dispatch_busy(hctx, true); | ||||
|  		__blk_mq_requeue_request(rq); | ||||
|  		break; | ||||
| @@ -1727,6 +1736,18 @@ static blk_status_t __blk_mq_issue_directly(struct blk_mq_hw_ctx *hctx,
 | ||||
|  	return ret; | ||||
|  } | ||||
|   | ||||
| +/*
 | ||||
| + * Don't allow direct dispatch of anything but regular reads/writes,
 | ||||
| + * as some of the other commands can potentially share request space
 | ||||
| + * with data we need for the IO scheduler. If we attempt a direct dispatch
 | ||||
| + * on those and fail, we can't safely add it to the scheduler afterwards
 | ||||
| + * without potentially overwriting data that the driver has already written.
 | ||||
| + */
 | ||||
| +static bool blk_rq_can_direct_dispatch(struct request *rq)
 | ||||
| +{
 | ||||
| +	return req_op(rq) == REQ_OP_READ || req_op(rq) == REQ_OP_WRITE;
 | ||||
| +}
 | ||||
| +
 | ||||
|  static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx, | ||||
|  						struct request *rq, | ||||
|  						blk_qc_t *cookie, | ||||
| @@ -1748,7 +1769,7 @@ static blk_status_t __blk_mq_try_issue_directly(struct blk_mq_hw_ctx *hctx,
 | ||||
|  		goto insert; | ||||
|  	} | ||||
|   | ||||
| -	if (q->elevator && !bypass_insert)
 | ||||
| +	if (!blk_rq_can_direct_dispatch(rq) || (q->elevator && !bypass_insert))
 | ||||
|  		goto insert; | ||||
|   | ||||
|  	if (!blk_mq_get_dispatch_budget(hctx)) | ||||
| @@ -1810,6 +1831,9 @@ void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
 | ||||
|  		struct request *rq = list_first_entry(list, struct request, | ||||
|  				queuelist); | ||||
|   | ||||
| +		if (!blk_rq_can_direct_dispatch(rq))
 | ||||
| +			break;
 | ||||
| +
 | ||||
|  		list_del_init(&rq->queuelist); | ||||
|  		ret = blk_mq_request_issue_directly(rq); | ||||
|  		if (ret != BLK_STS_OK) { | ||||
| -- 
 | ||||
| 2.19.2 | ||||
| 
 | ||||
							
								
								
									
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							| @ -1 +1 @@ | ||||
| d0897090458211f9c6b2d7f5af87f4d3b0403f69 | ||||
| b72f711a4efadfaa8a16f9cb708bfe1ce6125906 | ||||
|  | ||||
| @ -69,7 +69,7 @@ Summary: The Linux kernel | ||||
| # The rc snapshot level | ||||
| %global rcrev 5 | ||||
| # The git snapshot level | ||||
| %define gitrev 2 | ||||
| %define gitrev 3 | ||||
| # Set rpm version accordingly | ||||
| %define rpmversion 4.%{upstream_sublevel}.0 | ||||
| %endif | ||||
| @ -609,9 +609,6 @@ Patch504: iio-accel-kxcjk1013-Add-more-hardware-ids.patch | ||||
| # rhbz 1645070 patch queued upstream for merging into 4.21 | ||||
| Patch505: asus-fx503-keyb.patch | ||||
| 
 | ||||
| # https://bugzilla.kernel.org/show_bug.cgi?id=201685 | ||||
| Patch506: blk-mq-fix-corruption-with-direct-issue.patch | ||||
| 
 | ||||
| # END OF PATCH DEFINITIONS | ||||
| 
 | ||||
| %endif | ||||
| @ -1884,6 +1881,9 @@ fi | ||||
| # | ||||
| # | ||||
| %changelog | ||||
| * Fri Dec 07 2018 Justin M. Forbes <jforbes@fedoraproject.org> - 4.20.0-0.rc5.git3.1 | ||||
| - Linux v4.20-rc5-86-gb72f711a4efa | ||||
| 
 | ||||
| * Wed Dec 05 2018 Justin M. Forbes <jforbes@fedoraproject.org> - 4.20.0-0.rc5.git2.1 | ||||
| - Linux v4.20-rc5-44-gd08970904582 | ||||
| 
 | ||||
|  | ||||
							
								
								
									
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							| @ -1,3 +1,3 @@ | ||||
| SHA512 (linux-4.19.tar.xz) = ab67cc746b375a8b135e8b23e35e1d6787930d19b3c26b2679787d62951cbdbc3bb66f8ededeb9b890e5008b2459397f9018f1a6772fdef67780b06a4cb9f6f4 | ||||
| SHA512 (patch-4.20-rc5.xz) = 389daea25e1a19050fa2e7f4eb7cc8e462a83560a06b43b5bd8458bfcf3754c987660c2b42f9adeacd956342f4520c45d2982fbee4cfd2b8825f9153db06aaa9 | ||||
| SHA512 (patch-4.20-rc5-git2.xz) = 7f7c2f053d314ced612c773a023b171f24c60a7f41878557d77e307239b88b0d12d7532e3ba0b377959a12570fd639d5ad71960e87fdd1d21ff22296c4ea4167 | ||||
| SHA512 (patch-4.20-rc5-git3.xz) = 1b7cb0ddc1213104c001fb0dc9dedc03bf5c482d6823de685a661fafb5458d413868d4f07f23013bb85c258e9eda73fb12d6089e0df97c667733fb79eb8fcf17 | ||||
|  | ||||
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