[PATCH PREVIEW 0/4] nvme: keep alive and connection lost

block/Makefile

@@ -26,7 +26,8 @@ obj-$(CONFIG_MQ_IOSCHED_KYBER)	+= kyber-iosched.o
 bfq-y				:= bfq-iosched.o bfq-wf2q.o bfq-cgroup.o
 obj-$(CONFIG_IOSCHED_BFQ)	+= bfq.o
 
-obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o
+obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o blk-integrity.o t10-pi.o \
+				   bio-integrity-auto.o
 obj-$(CONFIG_BLK_DEV_ZONED)	+= blk-zoned.o
 obj-$(CONFIG_BLK_WBT)		+= blk-wbt.o
 obj-$(CONFIG_BLK_DEBUG_FS)	+= blk-mq-debugfs.o

block/bio-integrity-auto.c

@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2007, 2008, 2009 Oracle Corporation
+ * Written by: Martin K. Petersen <martin.petersen@oracle.com>
+ *
+ * Automatically generate and verify integrity data on PI capable devices if the
+ * bio submitter didn't provide PI itself.  This ensures that kernel verifies
+ * data integrity even if the file system (or other user of the block device) is
+ * not aware of PI.
+ */
+#include <linux/blk-integrity.h>
+#include <linux/workqueue.h>
+#include "blk.h"
+
+struct bio_integrity_data {
+	struct bio			*bio;
+	struct bvec_iter		saved_bio_iter;
+	struct work_struct		work;
+	struct bio_integrity_payload	bip;
+	struct bio_vec			bvec;
+};
+
+static struct kmem_cache *bid_slab;
+static mempool_t bid_pool;
+static struct workqueue_struct *kintegrityd_wq;
+
+static void bio_integrity_finish(struct bio_integrity_data *bid)
+{
+	bid->bio->bi_integrity = NULL;
+	bid->bio->bi_opf &= ~REQ_INTEGRITY;
+	kfree(bvec_virt(bid->bip.bip_vec));
+	mempool_free(bid, &bid_pool);
+}
+
+static void bio_integrity_verify_fn(struct work_struct *work)
+{
+	struct bio_integrity_data *bid =
+		container_of(work, struct bio_integrity_data, work);
+	struct bio *bio = bid->bio;
+
+	blk_integrity_verify_iter(bio, &bid->saved_bio_iter);
+	bio_integrity_finish(bid);
+	bio_endio(bio);
+}
+
+/**
+ * __bio_integrity_endio - Integrity I/O completion function
+ * @bio:	Protected bio
+ *
+ * Normally I/O completion is done in interrupt context.  However, verifying I/O
+ * integrity is a time-consuming task which must be run in process context.
+ *
+ * This function postpones completion accordingly.
+ */
+bool __bio_integrity_endio(struct bio *bio)
+{
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
+	struct bio_integrity_payload *bip = bio_integrity(bio);
+	struct bio_integrity_data *bid =
+		container_of(bip, struct bio_integrity_data, bip);
+
+	if (bio_op(bio) == REQ_OP_READ && !bio->bi_status && bi->csum_type) {
+		INIT_WORK(&bid->work, bio_integrity_verify_fn);
+		queue_work(kintegrityd_wq, &bid->work);
+		return false;
+	}
+
+	bio_integrity_finish(bid);
+	return true;
+}
+
+/**
+ * bio_integrity_prep - Prepare bio for integrity I/O
+ * @bio:	bio to prepare
+ *
+ * Checks if the bio already has an integrity payload attached.  If it does, the
+ * payload has been generated by another kernel subsystem, and we just pass it
+ * through.
+ * Otherwise allocates integrity payload and for writes the integrity metadata
+ * will be generated.  For reads, the completion handler will verify the
+ * metadata.
+ */
+bool bio_integrity_prep(struct bio *bio)
+{
+	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
+	struct bio_integrity_data *bid;
+	gfp_t gfp = GFP_NOIO;
+	unsigned int len;
+	void *buf;
+
+	if (!bi)
+		return true;
+
+	if (!bio_sectors(bio))
+		return true;
+
+	/* Already protected? */
+	if (bio_integrity(bio))
+		return true;
+
+	switch (bio_op(bio)) {
+	case REQ_OP_READ:
+		if (bi->flags & BLK_INTEGRITY_NOVERIFY)
+			return true;
+		break;
+	case REQ_OP_WRITE:
+		if (bi->flags & BLK_INTEGRITY_NOGENERATE)
+			return true;
+
+		/*
+		 * Zero the memory allocated to not leak uninitialized kernel
+		 * memory to disk for non-integrity metadata where nothing else
+		 * initializes the memory.
+		 */
+		if (bi->csum_type == BLK_INTEGRITY_CSUM_NONE)
+			gfp |= __GFP_ZERO;
+		break;
+	default:
+		return true;
+	}
+
+	if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
+		return true;
+
+	/* Allocate kernel buffer for protection data */
+	len = bio_integrity_bytes(bi, bio_sectors(bio));
+	buf = kmalloc(len, gfp);
+	if (!buf)
+		goto err_end_io;
+	bid = mempool_alloc(&bid_pool, GFP_NOIO);
+	if (!bid)
+		goto err_free_buf;
+	bio_integrity_init(bio, &bid->bip, &bid->bvec, 1);
+
+	bid->bio = bio;
+
+	bid->bip.bip_flags |= BIP_BLOCK_INTEGRITY;
+	bip_set_seed(&bid->bip, bio->bi_iter.bi_sector);
+
+	if (bi->csum_type == BLK_INTEGRITY_CSUM_IP)
+		bid->bip.bip_flags |= BIP_IP_CHECKSUM;
+	if (bi->csum_type)
+		bid->bip.bip_flags |= BIP_CHECK_GUARD;
+	if (bi->flags & BLK_INTEGRITY_REF_TAG)
+		bid->bip.bip_flags |= BIP_CHECK_REFTAG;
+
+	if (bio_integrity_add_page(bio, virt_to_page(buf), len,
+			offset_in_page(buf)) < len)
+		goto err_end_io;
+
+	/* Auto-generate integrity metadata if this is a write */
+	if (bio_data_dir(bio) == WRITE)
+		blk_integrity_generate(bio);
+	else
+		bid->saved_bio_iter = bio->bi_iter;
+	return true;
+
+err_free_buf:
+	kfree(buf);
+err_end_io:
+	bio->bi_status = BLK_STS_RESOURCE;
+	bio_endio(bio);
+	return false;
+}
+EXPORT_SYMBOL(bio_integrity_prep);
+
+void blk_flush_integrity(void)
+{
+	flush_workqueue(kintegrityd_wq);
+}
+
+static int __init blk_integrity_auto_init(void)
+{
+	bid_slab = kmem_cache_create("bio_integrity_data",
+			sizeof(struct bio_integrity_data), 0,
+			SLAB_HWCACHE_ALIGN | SLAB_PANIC, NULL);
+
+	if (mempool_init_slab_pool(&bid_pool, BIO_POOL_SIZE, bid_slab))
+		panic("bio: can't create integrity pool\n");
+
+	/*
+	 * kintegrityd won't block much but may burn a lot of CPU cycles.
+	 * Make it highpri CPU intensive wq with max concurrency of 1.
+	 */
+	kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
+					 WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
+	if (!kintegrityd_wq)
+		panic("Failed to create kintegrityd\n");
+	return 0;
+}
+subsys_initcall(blk_integrity_auto_init);