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Gateway) with SMTP id AE.DF.28392.0D74B646; Mon, 22 May 2023 19:45:36 +0900 (KST) Received: from green245.sa.corp.samsungelectronics.net (unknown [107.99.41.245]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20230522104532epsmtip2839b424711300915eee77a57ffa0f158~hcVH0JBQe1645416454epsmtip22; Mon, 22 May 2023 10:45:32 +0000 (GMT) From: Nitesh Shetty To: Jens Axboe , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, Keith Busch , Christoph Hellwig , Sagi Grimberg , James Smart , Chaitanya Kulkarni , Alexander Viro , Christian Brauner , "Matthew Wilcox (Oracle)" , Andrew Morton Cc: martin.petersen@oracle.com, linux-scsi@vger.kernel.org, James.Bottomley@HansenPartnership.com, bvanassche@acm.org, hare@suse.de, ming.lei@redhat.com, dlemoal@kernel.org, anuj20.g@samsung.com, joshi.k@samsung.com, nitheshshetty@gmail.com, gost.dev@samsung.com, Nitesh Shetty , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v11 2/9] block: Add copy offload support infrastructure Date: Mon, 22 May 2023 16:11:33 +0530 Message-Id: <20230522104146.2856-3-nj.shetty@samsung.com> X-Mailer: git-send-email 2.35.1.500.gb896f729e2 In-Reply-To: <20230522104146.2856-1-nj.shetty@samsung.com> MIME-Version: 1.0 X-Brightmail-Tracker: H4sIAAAAAAAAA01TaUxUVxjlvje8GdCxD9B4WVTyxLAJzCBMLyJihZZX1BRD05D+oSM8GYRZ OosUEsOmtEW2ohAciCJt2URGAQlrWxbLVjJStjANS1NoZMeBWpFQyjDY+u98555zz/2+m4+D W9aybTjREiUjlwhjKcKcVd/h7OxWdiEmkjdehSFN7884KtJUESglZxNHD8azCTTfoQcof2Ud R1M/+qPWpUJTNPZTI4ZaSnIxVPHgKYYeZ3NQ8/0XGHq6tUig3PYRgGaG1Rhq1bmiltYeFhps KiLQRNWWKbpXOsNGN0cbCFTW9Q+G2m+lYqhhOhmg+o17OKqeX2ahbp0t0m52maKNV0XEmcP0 4NA5Wj3ZT9CN6nE2rZ14zKLzc3sJurbchR7sV9E1lV8TdI0+l013F2yw6NrvEunmsSSCzkxd IugXMzoWvfzDMEFn1VWCEKtPY06JGGEkI7dnJBHSyGhJlB91LjQ8INxbwOO78X3Qu5S9RChm /KjA8yFuH0THbk+Ksr8qjFVtUyFChYLyOH1KLlUpGXuRVKH0oxhZZKzMS+auEIoVKkmUu4RR nuTzeJ7e28LPYkRPFtowWW7YF5OVnawksB6UDsw4kPSCw1+WsdKBOceSbAZwQf/XbqEHUPMq 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i6YJf5ktVt/tZ7N4ffgTo8W0Dz+ZLR7st7fY+242q8XNAzuZLPYsmsRksXL1USaLjf0cFrsX fmSyOPr/LZvFpEPXGC2eXp3FZLH3lrbFnr0nWSwu75rDZnFvzX9Wi/nLnrJbdF/fwWax/Pg/ JotDk5uZLHY8aWS02PZ7PrPFutfvWSxO3JK2OP/3OKvF7x9z2BzkPC5f8faYdf8sm8fOWXfZ Pc7f28jiMW3SKTaPzSu0PC6fLfXYtKqTzWPTp0nsHidm/Gbx2Lyk3mP3zQY2j97md2weH5/e YvF4v+8qm0ffllWMAcJRXDYpqTmZZalF+nYJXBlb3xxkKpgUUXF/1RGWBsaf7l2MHBwSAiYS U34pdzFycggJ7GCU+HFCHcSWEJCUWPb3CDOELSyx8t9z9i5GLqCaZiaJjZ+nsoD0sgloS5z+ zwESFxH4wCyxfssiRpAGZoHbzBLbrkeA2MIC7hKXzm8Ai7MIqEp8uXWZHaSXV8BSYscuVYgT 9CX67wuCVHAKWEm8uDiLGSQsBFQxYZkRSJhXQFDi5MwnLBDD5SWat85mnsAoMAtJahaS1AJG plWMkqkFxbnpucWGBUZ5qeV6xYm5xaV56XrJ+bmbGMEpQUtrB+OeVR/0DjEycTAeYpTgYFYS 4Q3sS04R4k1JrKxKLcqPLyrNSS0+xCjNwaIkznuh62S8kEB6YklqdmpqQWoRTJaJg1OqgUlL 1n/6yXROxbMh/j2P3k/ecs00P2tFpz/rhuaIGQ17r84pP79hn0x1RQfP4aolz/aYtlruWDXz eG1v8s7IM9sNYpLMnk7csljGKvm0+PfL4lqrfu9Yc3fdN6Gt0vLWf4PckwTTKwtdFsZsn1De Nm3rv5gmQznGCVfkjKJ2i6mHpOzsZriYpfs6m3eiZXYX74/Vf2vb0zOmeloelZ522V73xadg VVvn1KWRdy4lHc9ILPjk0XzLtaGuNsXQqORnoby4lt35j198L+byKMtzJ4c+5on5Y9fwcu7t rOVz1muZJaR/jHpxL/gAc0+QZaPkjK8pG7my/lef0jyfbBEnUDpX01+uQcBvjeOc65N0lFiK MxINtZiLihMB06tcTXgDAAA= X-CMS-MailID: 20230522104536epcas5p23dd8108dd267ec588e5c36e8f9eb9fe8 X-Msg-Generator: CA X-Sendblock-Type: REQ_APPROVE CMS-TYPE: 105P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20230522104536epcas5p23dd8108dd267ec588e5c36e8f9eb9fe8 References: <20230522104146.2856-1-nj.shetty@samsung.com> Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Introduce blkdev_issue_copy which takes similar arguments as copy_file_range and performs copy offload between two bdevs. Introduce REQ_COPY copy offload operation flag. Create a read-write bio pair with a token as payload and submitted to the device in order. Read request populates token with source specific information which is then passed with write request. This design is courtesy Mikulas Patocka's token based copy Larger copy will be divided, based on max_copy_sectors limit. Signed-off-by: Nitesh Shetty Signed-off-by: Anuj Gupta --- block/blk-lib.c | 235 ++++++++++++++++++++++++++++++++++++++ block/blk.h | 2 + include/linux/blk_types.h | 25 ++++ include/linux/blkdev.h | 3 + 4 files changed, 265 insertions(+) diff --git a/block/blk-lib.c b/block/blk-lib.c index e59c3069e835..ed089e703cb1 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -115,6 +115,241 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, } EXPORT_SYMBOL(blkdev_issue_discard); +/* + * For synchronous copy offload/emulation, wait and process all in-flight BIOs. + * This must only be called once all bios have been issued so that the refcount + * can only decrease. This just waits for all bios to make it through + * blkdev_copy_write_endio. + */ +static int blkdev_copy_wait_completion(struct cio *cio) +{ + int ret; + + if (cio->endio) + return 0; + + if (atomic_read(&cio->refcount)) { + __set_current_state(TASK_UNINTERRUPTIBLE); + blk_io_schedule(); + } + + ret = cio->comp_len; + kfree(cio); + + return ret; +} + +static void blkdev_copy_offload_write_endio(struct bio *bio) +{ + struct copy_ctx *ctx = bio->bi_private; + struct cio *cio = ctx->cio; + sector_t clen; + + if (bio->bi_status) { + clen = (bio->bi_iter.bi_sector << SECTOR_SHIFT) - cio->pos_out; + cio->comp_len = min_t(sector_t, clen, cio->comp_len); + } + __free_page(bio->bi_io_vec[0].bv_page); + bio_put(bio); + + kfree(ctx); + if (!atomic_dec_and_test(&cio->refcount)) + return; + if (cio->endio) { + cio->endio(cio->private, cio->comp_len); + kfree(cio); + } else + blk_wake_io_task(cio->waiter); +} + +static void blkdev_copy_offload_read_endio(struct bio *read_bio) +{ + struct copy_ctx *ctx = read_bio->bi_private; + struct cio *cio = ctx->cio; + sector_t clen; + + if (read_bio->bi_status) { + clen = (read_bio->bi_iter.bi_sector << SECTOR_SHIFT) + - cio->pos_in; + cio->comp_len = min_t(sector_t, clen, cio->comp_len); + __free_page(read_bio->bi_io_vec[0].bv_page); + bio_put(ctx->write_bio); + bio_put(read_bio); + kfree(ctx); + if (atomic_dec_and_test(&cio->refcount)) { + if (cio->endio) { + cio->endio(cio->private, cio->comp_len); + kfree(cio); + } else + blk_wake_io_task(cio->waiter); + } + return; + } + + schedule_work(&ctx->dispatch_work); + bio_put(read_bio); +} + +static void blkdev_copy_dispatch_work(struct work_struct *work) +{ + struct copy_ctx *ctx = container_of(work, struct copy_ctx, + dispatch_work); + + submit_bio(ctx->write_bio); +} + +/* + * __blkdev_copy_offload - Use device's native copy offload feature. + * we perform copy operation by sending 2 bio. + * 1. First we send a read bio with REQ_COPY flag along with a token and source + * and length. Once read bio reaches driver layer, device driver adds all the + * source info to token and does a fake completion. + * 2. Once read operation completes, we issue write with REQ_COPY flag with same + * token. In driver layer, token info is used to form a copy offload command. + * + * Returns the length of bytes copied or error if encountered + */ +static int __blkdev_copy_offload(struct block_device *bdev_in, loff_t pos_in, + struct block_device *bdev_out, loff_t pos_out, size_t len, + cio_iodone_t endio, void *private, gfp_t gfp_mask) +{ + struct cio *cio; + struct copy_ctx *ctx; + struct bio *read_bio, *write_bio; + struct page *token; + sector_t copy_len; + sector_t rem, max_copy_len; + + cio = kzalloc(sizeof(struct cio), GFP_KERNEL); + if (!cio) + return -ENOMEM; + atomic_set(&cio->refcount, 0); + cio->waiter = current; + cio->endio = endio; + cio->private = private; + + max_copy_len = min(bdev_max_copy_sectors(bdev_in), + bdev_max_copy_sectors(bdev_out)) << SECTOR_SHIFT; + + cio->pos_in = pos_in; + cio->pos_out = pos_out; + /* If there is a error, comp_len will be set to least successfully + * completed copied length + */ + cio->comp_len = len; + for (rem = len; rem > 0; rem -= copy_len) { + copy_len = min(rem, max_copy_len); + + token = alloc_page(gfp_mask); + if (unlikely(!token)) + goto err_token; + + ctx = kzalloc(sizeof(struct copy_ctx), gfp_mask); + if (!ctx) + goto err_ctx; + read_bio = bio_alloc(bdev_in, 1, REQ_OP_READ | REQ_COPY + | REQ_SYNC | REQ_NOMERGE, gfp_mask); + if (!read_bio) + goto err_read_bio; + write_bio = bio_alloc(bdev_out, 1, REQ_OP_WRITE + | REQ_COPY | REQ_SYNC | REQ_NOMERGE, gfp_mask); + if (!write_bio) + goto err_write_bio; + + ctx->cio = cio; + ctx->write_bio = write_bio; + INIT_WORK(&ctx->dispatch_work, blkdev_copy_dispatch_work); + + __bio_add_page(read_bio, token, PAGE_SIZE, 0); + read_bio->bi_iter.bi_size = copy_len; + read_bio->bi_iter.bi_sector = pos_in >> SECTOR_SHIFT; + read_bio->bi_end_io = blkdev_copy_offload_read_endio; + read_bio->bi_private = ctx; + + __bio_add_page(write_bio, token, PAGE_SIZE, 0); + write_bio->bi_iter.bi_size = copy_len; + write_bio->bi_end_io = blkdev_copy_offload_write_endio; + write_bio->bi_iter.bi_sector = pos_out >> SECTOR_SHIFT; + write_bio->bi_private = ctx; + + atomic_inc(&cio->refcount); + submit_bio(read_bio); + pos_in += copy_len; + pos_out += copy_len; + } + + /* Wait for completion of all IO's*/ + return blkdev_copy_wait_completion(cio); + +err_write_bio: + bio_put(read_bio); +err_read_bio: + kfree(ctx); +err_ctx: + __free_page(token); +err_token: + cio->comp_len = min_t(sector_t, cio->comp_len, (len - rem)); + if (!atomic_read(&cio->refcount)) + return -ENOMEM; + /* Wait for submitted IOs to complete */ + return blkdev_copy_wait_completion(cio); +} + +static inline int blkdev_copy_sanity_check(struct block_device *bdev_in, + loff_t pos_in, struct block_device *bdev_out, loff_t pos_out, + size_t len) +{ + unsigned int align = max(bdev_logical_block_size(bdev_out), + bdev_logical_block_size(bdev_in)) - 1; + + if (bdev_read_only(bdev_out)) + return -EPERM; + + if ((pos_in & align) || (pos_out & align) || (len & align) || !len || + len >= COPY_MAX_BYTES) + return -EINVAL; + + return 0; +} + +/* + * @bdev_in: source block device + * @pos_in: source offset + * @bdev_out: destination block device + * @pos_out: destination offset + * @len: length in bytes to be copied + * @endio: endio function to be called on completion of copy operation, + * for synchronous operation this should be NULL + * @private: endio function will be called with this private data, should be + * NULL, if operation is synchronous in nature + * @gfp_mask: memory allocation flags (for bio_alloc) + * + * Returns the length of bytes copied or error if encountered + * + * Description: + * Copy source offset from source block device to destination block + * device. Max total length of copy is limited to MAX_COPY_TOTAL_LENGTH + */ +int blkdev_issue_copy(struct block_device *bdev_in, loff_t pos_in, + struct block_device *bdev_out, loff_t pos_out, size_t len, + cio_iodone_t endio, void *private, gfp_t gfp_mask) +{ + struct request_queue *q_in = bdev_get_queue(bdev_in); + struct request_queue *q_out = bdev_get_queue(bdev_out); + int ret; + + ret = blkdev_copy_sanity_check(bdev_in, pos_in, bdev_out, pos_out, len); + if (ret) + return ret; + + if (blk_queue_copy(q_in) && blk_queue_copy(q_out)) + ret = __blkdev_copy_offload(bdev_in, pos_in, bdev_out, pos_out, + len, endio, private, gfp_mask); + + return ret; +} +EXPORT_SYMBOL_GPL(blkdev_issue_copy); + static int __blkdev_issue_write_zeroes(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct bio **biop, unsigned flags) diff --git a/block/blk.h b/block/blk.h index 45547bcf1119..ec48a237fe12 100644 --- a/block/blk.h +++ b/block/blk.h @@ -303,6 +303,8 @@ static inline bool bio_may_exceed_limits(struct bio *bio, break; } + if (unlikely(op_is_copy(bio->bi_opf))) + return false; /* * All drivers must accept single-segments bios that are <= PAGE_SIZE. * This is a quick and dirty check that relies on the fact that diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h index 740afe80f297..0117e33087e1 100644 --- a/include/linux/blk_types.h +++ b/include/linux/blk_types.h @@ -420,6 +420,7 @@ enum req_flag_bits { */ /* for REQ_OP_WRITE_ZEROES: */ __REQ_NOUNMAP, /* do not free blocks when zeroing */ + __REQ_COPY, /* copy request */ __REQ_NR_BITS, /* stops here */ }; @@ -444,6 +445,7 @@ enum req_flag_bits { #define REQ_POLLED (__force blk_opf_t)(1ULL << __REQ_POLLED) #define REQ_ALLOC_CACHE (__force blk_opf_t)(1ULL << __REQ_ALLOC_CACHE) #define REQ_SWAP (__force blk_opf_t)(1ULL << __REQ_SWAP) +#define REQ_COPY ((__force blk_opf_t)(1ULL << __REQ_COPY)) #define REQ_DRV (__force blk_opf_t)(1ULL << __REQ_DRV) #define REQ_FS_PRIVATE (__force blk_opf_t)(1ULL << __REQ_FS_PRIVATE) @@ -474,6 +476,11 @@ static inline bool op_is_write(blk_opf_t op) return !!(op & (__force blk_opf_t)1); } +static inline bool op_is_copy(blk_opf_t op) +{ + return op & REQ_COPY; +} + /* * Check if the bio or request is one that needs special treatment in the * flush state machine. @@ -533,4 +540,22 @@ struct blk_rq_stat { u64 batch; }; +typedef void (cio_iodone_t)(void *private, int comp_len); + +struct cio { + struct task_struct *waiter; /* waiting task (NULL if none) */ + atomic_t refcount; + loff_t pos_in; + loff_t pos_out; + size_t comp_len; + cio_iodone_t *endio; /* applicable for async operation */ + void *private; /* applicable for async operation */ +}; + +struct copy_ctx { + struct cio *cio; + struct work_struct dispatch_work; + struct bio *write_bio; +}; + #endif /* __LINUX_BLK_TYPES_H */ diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index c9bf11adccb3..6f2814ab4741 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1051,6 +1051,9 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct bio **biop); int blkdev_issue_secure_erase(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp); +int blkdev_issue_copy(struct block_device *bdev_in, loff_t pos_in, + struct block_device *bdev_out, loff_t pos_out, size_t len, + cio_iodone_t end_io, void *private, gfp_t gfp_mask); #define BLKDEV_ZERO_NOUNMAP (1 << 0) /* do not free blocks */ #define BLKDEV_ZERO_NOFALLBACK (1 << 1) /* don't write explicit zeroes */