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Fri, 11 Aug 2023 19:56:59 +0900 (KST) Received: from green245.sa.corp.samsungelectronics.net (unknown [107.99.41.245]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20230811105654epsmtip2f5ca9c0c86786979107bcf3f14805923~6TvKvI32t1192511925epsmtip2k; Fri, 11 Aug 2023 10:56:54 +0000 (GMT) From: Nitesh Shetty To: Jens Axboe , Jonathan Corbet , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, Keith Busch , Christoph Hellwig , Sagi Grimberg , Chaitanya Kulkarni , Alexander Viro , Christian Brauner Cc: martin.petersen@oracle.com, mcgrof@kernel.org, dlemoal@kernel.org, gost.dev@samsung.com, Nitesh Shetty , Anuj Gupta , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v14 03/11] block: add copy offload support Date: Fri, 11 Aug 2023 16:22:46 +0530 Message-Id: <20230811105300.15889-4-nj.shetty@samsung.com> X-Mailer: git-send-email 2.35.1.500.gb896f729e2 In-Reply-To: <20230811105300.15889-1-nj.shetty@samsung.com> MIME-Version: 1.0 X-Brightmail-Tracker: H4sIAAAAAAAAA02Te1BUVRzHO/fevVwYaK6L1QFHY7aoEQV2cdkOJIhIeEmbYVLH0mrd2CsQ sLvuQ6wZC+ORwsAi4GDLEgImCiZKQLzDRUFAghZ5OiAm9IABgkyQRWyXBfO/z+/7e//OHArn mkhnKlKmZpUySTSPtCMqmza+6f6pU6+UP9jliErbmnH0dfoTHJUMaUk00TQL0GjjNwCN/LwN 1U/lcNBAYzWGLpXcxFCGoRegsR4dhuoHN6H8pPMEqqtvJVB3jZ5EeRfGbFBRyxKG+tPHAKo0 5eHoysQ0gW4NrkOdT1o4AS8zncPXCKa7Q8OUFZ8imR/Pf8XUDsSRTGFaJodJjZ8imZmxQYKZ bughmbTyYsD8U7aBKRudxELtD0RtjWAlUlbpwsrC5NJIWbgfb9ce8Q6xt4gvcBf4oLd4LjJJ DOvHC9od6h4cGW3el+dyVBKtMUuhEpWK5+m/VSnXqFmXCLlK7cdjFdJohVDhoZLEqDSycA8Z q/YV8Ple3ubAQ1ERN7JnSUWR/7HsU5UgDjR4JQNbCtJCOFJehCUDO4pL1wI43jsNrMYsgCNz icQzo+REB76acsNwB7c6qgH811TLsRqJGMxPnTLnUxRJb4LtTymLvpaOw+HV2sLlujhtwKAu fxKzlHKkfeHd70dICxO0K8z+qQdY2MGsDxTct7EUgrQn1N5bY5Ft6bfhdJmRtIasga3fjhIW xulXYXxFzvJEkH5KQdPpdNI6ahBM+k27wo5wvKXcxsrO8C9t0grHwktZF0lrcgKAuj4dsDq2 wcQ2LW4ZAqc3wtIaT6u8Hp5pu4JZG78IU02jmFV3gFXfrfJr8HLpuZW+TrB37sQKM1Cvn1q5 dhqAxsYhTjpw0T23kO65hXT/tz4H8GLgxCpUMeFsmLdCIGNjn71zmDymDCz/AregKtCft+Rh ABgFDABSOG+tg98eo5TrIJV8/gWrlIuVmmhWZQDe5oOfxp1fCpObv5FMLRYIffhCkUgk9Nki EvBecZhIzJVy6XCJmo1iWQWrXM3DKFvnOCw411GYdWzzx4/mxu0bTOvnA9vZ4fmqnAdGY/Vt ne/MQmSfaHG7/4EAW3WztFR6L6Wwoq//4uGdE/ZU4WTtydCH2n0HZS0a+etdR47zDeKakMtu CU6ZKe2leUU99MODY/QPCX8+Fj3onHkX+70+kMe4I7qu72rGnYziXZ99eVa/P+VmV2BdR6tf VlDT0cXDBSHG3UTBO7/+vb390Hu3NbHxQ8nq+ke5mR+9saE9k5k6kvVB8MnuWZ2YGA54vMWr 1znjjIb7vv7+XlfXC9f2X79roxgJ0X6ydCtw3olbYjq+GGT3wsK+YSfiw85fUsTSdWc3++9o 9trLL44s79tZwVnI1Ff/cZ1HqCIkAjdcqZL8B+zNr+yOBAAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrNIsWRmVeSWpSXmKPExsWy7bCSvO5v4WspBju+qFusP3WM2aJpwl9m i9V3+9ksXh/+xGjx5EA7o8WD/fYWe9/NZrW4eWAnk8XK1UeZLCYdusZo8fTqLCaLvbe0LRa2 LWGx2LP3JIvF5V1z2CzmL3vKbrH8+D8mixsTnjJabPs9n9li3ev3LBYnbklbnP97nNVBzOP8 vY0sHpfPlnpsWtXJ5rF5Sb3H7psNbB6L+yazevQ2v2Pz+Pj0FovH+31X2Tz6tqxi9Pi8Sc5j 05O3TAE8UVw2Kak5mWWpRfp2CVwZR6Z/YitYblcxvXMbYwPjPqMuRk4OCQETiSOHrjB3MXJx CAlsZ5TYfuokI0RCUmLZ3yPMELawxMp/z9khipqZJLZd2wDkcHCwCWhLnP7PARIXEehilujc +Y4FpIFZ4ByTxMnb/CC2sICVxO2lD9hAbBYBVYnp26+CLeAFit9c9BBsjoSAvkT/fUGQMKeA tcT7TZfAyoWASj4sOwhVLihxcuYTqPHyEs1bZzNPYBSYhSQ1C0lqASPTKkbR1ILi3PTc5AJD veLE3OLSvHS95PzcTYzg+NQK2sG4bP1fvUOMTByMhxglOJiVRHhtgy+lCPGmJFZWpRblxxeV 5qQWH2KU5mBREudVzulMERJITyxJzU5NLUgtgskycXBKNTAFXtlT9fcIi+GZW3PW9960vHor /sSWqFxV/afrNN8rTIo62b3ZMKzg/dk59c9mJN7waPQo8he2qTdyq/cxElNT/tEpsGbvvNdx FyPXt4jOTd7j6Hcl4wHPmbWHt4WGBl7snrz2QvrBYpZ4dscvawWnbRbcs+2fu4/zw6UhdoLR W50OMwpF3mXz9g6dbLs/6OyBsEkmYYl+cfYar24u8WcKFXw4kft33OXbu06oFXkn3srk1xIR Mlk9of/273mXwrYZnFh06PuCg1cM9I1ygldP/7buh2/kvtu20+O7HI7lVNXmex1+7sh4rrN3 UUvxfCEBX5OQDXsLN5086PPaa+vp89L7PxV1OZxze3jFdJqfEktxRqKhFnNRcSIAPOycrD4D AAA= X-CMS-MailID: 20230811105659epcas5p1982eeaeb580c4cb9b23a29270945be08 X-Msg-Generator: CA X-Sendblock-Type: REQ_APPROVE CMS-TYPE: 105P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20230811105659epcas5p1982eeaeb580c4cb9b23a29270945be08 References: <20230811105300.15889-1-nj.shetty@samsung.com> X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL, SPF_HELO_PASS,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: 1773942449848108545 X-GMAIL-MSGID: 1773942449848108545 Introduce blkdev_copy_offload to perform copy offload. Issue REQ_OP_COPY_SRC with source info along with taking a plug. This flows till request layer and waits for dst bio to arrive. Issue REQ_OP_COPY_DST with destination info and this bio reaches request layer and merges with src request. For any reason, if a request comes to the driver with only one of src/dst bio, we fail the copy offload. Larger copy will be divided, based on max_copy_sectors limit. Signed-off-by: Anuj Gupta Signed-off-by: Nitesh Shetty --- block/blk-lib.c | 196 +++++++++++++++++++++++++++++++++++++++++ include/linux/blkdev.h | 4 + 2 files changed, 200 insertions(+) diff --git a/block/blk-lib.c b/block/blk-lib.c index e59c3069e835..ad512293730b 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -10,6 +10,22 @@ #include "blk.h" +/* Keeps track of all outstanding copy IO */ +struct blkdev_copy_io { + atomic_t refcount; + ssize_t copied; + int status; + struct task_struct *waiter; + void (*endio)(void *private, int status, ssize_t copied); + void *private; +}; + +/* Keeps track of single outstanding copy offload IO */ +struct blkdev_copy_offload_io { + struct blkdev_copy_io *cio; + loff_t offset; +}; + static sector_t bio_discard_limit(struct block_device *bdev, sector_t sector) { unsigned int discard_granularity = bdev_discard_granularity(bdev); @@ -115,6 +131,186 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, } EXPORT_SYMBOL(blkdev_issue_discard); +static inline ssize_t 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 ((pos_in & align) || (pos_out & align) || (len & align) || !len || + len >= COPY_MAX_BYTES) + return -EINVAL; + + return 0; +} + +static inline void blkdev_copy_endio(struct blkdev_copy_io *cio) +{ + if (cio->endio) { + cio->endio(cio->private, cio->status, cio->copied); + kfree(cio); + } else { + struct task_struct *waiter = cio->waiter; + + WRITE_ONCE(cio->waiter, NULL); + blk_wake_io_task(waiter); + } +} + +/* + * 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 complete. + * Returns the length of bytes copied or error + */ +static ssize_t blkdev_copy_wait_io_completion(struct blkdev_copy_io *cio) +{ + ssize_t ret; + + for (;;) { + __set_current_state(TASK_UNINTERRUPTIBLE); + if (!READ_ONCE(cio->waiter)) + break; + blk_io_schedule(); + } + __set_current_state(TASK_RUNNING); + ret = cio->copied; + kfree(cio); + + return ret; +} + +static void blkdev_copy_offload_dst_endio(struct bio *bio) +{ + struct blkdev_copy_offload_io *offload_io = bio->bi_private; + struct blkdev_copy_io *cio = offload_io->cio; + + if (bio->bi_status) { + cio->copied = min_t(ssize_t, offload_io->offset, cio->copied); + if (!cio->status) + cio->status = blk_status_to_errno(bio->bi_status); + } + bio_put(bio); + + if (atomic_dec_and_test(&cio->refcount)) + blkdev_copy_endio(cio); +} + +/* + * @bdev: block device + * @pos_in: source offset + * @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, + * for synchronous operation this should be NULL + * @gfp_mask: memory allocation flags (for bio_alloc) + * + * For synchronous operation returns the length of bytes copied or error + * For asynchronous operation returns -EIOCBQUEUED or error + * + * Description: + * Copy source offset to destination offset within block device, using + * device's native copy offload feature. + * We perform copy operation by sending 2 bio's. + * 1. We take a plug and send a REQ_OP_COPY_SRC bio along with source + * sector and length. Once this bio reaches request layer, we form a + * request and wait for dst bio to arrive. + * 2. We issue REQ_OP_COPY_DST bio along with destination sector, length. + * Once this bio reaches request layer and find a request with previously + * sent source info we merge the destination bio and return. + * 3. Release the plug and request is sent to driver + * This design works only for drivers with request queue. + */ +ssize_t blkdev_copy_offload(struct block_device *bdev, loff_t pos_in, + loff_t pos_out, size_t len, + void (*endio)(void *, int, ssize_t), + void *private, gfp_t gfp) +{ + struct blkdev_copy_io *cio; + struct blkdev_copy_offload_io *offload_io; + struct bio *src_bio, *dst_bio; + ssize_t rem, chunk, ret; + ssize_t max_copy_bytes = bdev_max_copy_sectors(bdev) << SECTOR_SHIFT; + struct blk_plug plug; + + if (!max_copy_bytes) + return -EINVAL; + + ret = blkdev_copy_sanity_check(bdev, pos_in, bdev, pos_out, len); + if (ret) + return ret; + + cio = kzalloc(sizeof(*cio), GFP_KERNEL); + if (!cio) + return -ENOMEM; + atomic_set(&cio->refcount, 1); + cio->waiter = current; + cio->endio = endio; + cio->private = private; + + /* + * If there is a error, copied will be set to least successfully + * completed copied length + */ + cio->copied = len; + for (rem = len; rem > 0; rem -= chunk) { + chunk = min(rem, max_copy_bytes); + + offload_io = kzalloc(sizeof(*offload_io), GFP_KERNEL); + if (!offload_io) + goto err_free_cio; + offload_io->cio = cio; + /* + * For partial completion, we use offload_io->offset to truncate + * successful copy length + */ + offload_io->offset = len - rem; + + src_bio = bio_alloc(bdev, 0, REQ_OP_COPY_SRC, gfp); + if (!src_bio) + goto err_free_offload_io; + src_bio->bi_iter.bi_size = chunk; + src_bio->bi_iter.bi_sector = pos_in >> SECTOR_SHIFT; + + blk_start_plug(&plug); + dst_bio = blk_next_bio(src_bio, bdev, 0, REQ_OP_COPY_DST, gfp); + dst_bio->bi_iter.bi_size = chunk; + dst_bio->bi_iter.bi_sector = pos_out >> SECTOR_SHIFT; + dst_bio->bi_end_io = blkdev_copy_offload_dst_endio; + dst_bio->bi_private = offload_io; + + if (rem != chunk) + atomic_inc(&cio->refcount); + submit_bio(dst_bio); + blk_finish_plug(&plug); + pos_in += chunk; + pos_out += chunk; + } + + if (cio->endio) + return -EIOCBQUEUED; + + return blkdev_copy_wait_io_completion(cio); + +err_free_offload_io: + kfree(offload_io); +err_free_cio: + cio->copied = min_t(ssize_t, cio->copied, (len - rem)); + cio->status = -ENOMEM; + if (rem == len) { + kfree(cio); + return cio->status; + } + if (cio->endio) + return cio->status; + + return blkdev_copy_wait_io_completion(cio); +} +EXPORT_SYMBOL_GPL(blkdev_copy_offload); + 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/include/linux/blkdev.h b/include/linux/blkdev.h index 6ab3b0d60315..81558cb7c019 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1042,6 +1042,10 @@ 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); +ssize_t blkdev_copy_offload(struct block_device *bdev, loff_t pos_in, + loff_t pos_out, size_t len, + void (*endio)(void *, int, ssize_t), + 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 */