From fd6f32f78645db32b6b95a42e45da2ddd6de0e67 Mon Sep 17 00:00:00 2001 From: Juha-Matti Tilli Date: Sun, 2 Dec 2018 12:47:08 +0200 Subject: libata: whitelist all SAMSUNG MZ7KM* solid-state disks These devices support read zero after trim (RZAT), as they advertise to the OS. However, the OS doesn't believe the SSDs unless they are explicitly whitelisted. Acked-by: Martin K. Petersen Signed-off-by: Juha-Matti Tilli Signed-off-by: Jens Axboe --- drivers/ata/libata-core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c index a7f5202a4815..b8c3f9e6af89 100644 --- a/drivers/ata/libata-core.c +++ b/drivers/ata/libata-core.c @@ -4602,6 +4602,7 @@ static const struct ata_blacklist_entry ata_device_blacklist [] = { { "SSD*INTEL*", NULL, ATA_HORKAGE_ZERO_AFTER_TRIM, }, { "Samsung*SSD*", NULL, ATA_HORKAGE_ZERO_AFTER_TRIM, }, { "SAMSUNG*SSD*", NULL, ATA_HORKAGE_ZERO_AFTER_TRIM, }, + { "SAMSUNG*MZ7KM*", NULL, ATA_HORKAGE_ZERO_AFTER_TRIM, }, { "ST[1248][0248]0[FH]*", NULL, ATA_HORKAGE_ZERO_AFTER_TRIM, }, /* -- cgit v1.2.3 From ffe81d45322cc3cb140f0db080a4727ea284661e Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Tue, 4 Dec 2018 20:06:48 -0700 Subject: 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 If we later merge with this request, then the old tables are no longer valid.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 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 --- 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) { -- cgit v1.2.3