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Mon, 20 May 2024 20:44:54 +0900 (KST) Received: from epsmtrp1.samsung.com (unknown [182.195.40.13]) by epcas5p1.samsung.com (KnoxPortal) with ESMTPA id 20240520102906epcas5p15b5a0b3c8edd0bf3073030a792a328bb~RK6rliQlI1728917289epcas5p1S; Mon, 20 May 2024 10:29:05 +0000 (GMT) Received: from epsmgmc1p1new.samsung.com (unknown [182.195.42.40]) by epsmtrp1.samsung.com (KnoxPortal) with ESMTP id 20240520102905epsmtrp169417753e2cc00699cbe79d756354e11~RK6rkZBPI2026720267epsmtrp1N; Mon, 20 May 2024 10:29:05 +0000 (GMT) X-AuditID: b6c32a49-cefff700000025c2-cd-664b37b55210 Received: from epsmtip2.samsung.com ( [182.195.34.31]) by epsmgmc1p1new.samsung.com (Symantec Messaging Gateway) with SMTP id 77.ED.09238.1F52B466; Mon, 20 May 2024 19:29:05 +0900 (KST) Received: from green245.sa.corp.samsungelectronics.net (unknown [107.99.41.245]) by epsmtip2.samsung.com (KnoxPortal) with ESMTPA id 20240520102901epsmtip201169637c5bcedb66ae04a739ad6f033~RK6nifmXN2248422484epsmtip2r; Mon, 20 May 2024 10:29:01 +0000 (GMT) From: Nitesh Shetty To: Jens Axboe , Jonathan Corbet , Alasdair Kergon , Mike Snitzer , Mikulas Patocka , Keith Busch , Christoph Hellwig , Sagi Grimberg , Chaitanya Kulkarni , Alexander Viro , Christian Brauner , Jan Kara Cc: martin.petersen@oracle.com, bvanassche@acm.org, david@fromorbit.com, hare@suse.de, damien.lemoal@opensource.wdc.com, anuj20.g@samsung.com, joshi.k@samsung.com, nitheshshetty@gmail.com, gost.dev@samsung.com, Nitesh Shetty , Vincent Fu , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, dm-devel@lists.linux.dev, linux-nvme@lists.infradead.org, linux-fsdevel@vger.kernel.org Subject: [PATCH v20 04/12] block: add emulation for copy Date: Mon, 20 May 2024 15:50:17 +0530 Message-Id: <20240520102033.9361-5-nj.shetty@samsung.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20240520102033.9361-1-nj.shetty@samsung.com> X-Brightmail-Tracker: H4sIAAAAAAAAA0VTa1BUZRie75zl7C7N1hmw/CAxZrUpcVhYYpcPAm3KaQ4ukxSjSVF4Yg+X AZZlzy5KTggSCihyUWlYRIFdQMARheUm1yBAIaQRWQTjki5ORMitLIeAWBbr3/M+7/s+zzfP Ny8Pt1kl7HkRCjWjUtBRQsKaU9e5y8m5zkMW6mo04qiqtxtHJ7NWcFQ5lkmgmc5FgHLnn+PI 1H4aoOX+ARwZuscBKiwu4KCR9kYMNRfnYKi8sgtD+d8lY6hrbZZAOR1GgKaGtBhqGd2Nik7p Oai55Q4HDd66RKArpVNcVNaziqHs1CEMNZiSAKpbvoKj6zNzHHR79HX0+EwqQAMrPVbvOVCD 92VUbzGkGrVjXGpg/CaHGuzXUNUVaQRVoz9B/VqTB6imkUSC0p07b0VlJD8lqMaUCStqYWqU Q821DhHUOUMFoH4s/IHrb/tZpHc4Q8sZlSOjCImRRyjCfISygOAPgiVSV7Gz2BN5CB0VdDTj I9zn5+/8YUTUekxCxzg6SrNO+dMsK3TZ462K0agZx/AYVu0jZJTyKKW7UsTS0axGESZSMGov saurm2R98Ehk+MjaU66y7f1jpnIjlggeSdIBjwdJd1jb4pEO+DwbsgnABzo3C14EsPqRKh1Y r+NnAObrfsHMDfN8fcmfmKXRAuDShB5YihQMZj38h2tWJcjdsG+NZ+a3kJU4PFOTzTEXOPkA hyU3nmxI2ZIIdszc5Zoxh3wT5jX1cczLAtIT1ppEFrc3YOWNdtyM+aQXbK+d3zCDZA0fDrYa uZahfXDlScXm82zhbz2GTd4eTmee2sRHYfmFq4Rl+VsAtcNaYGnshSm9mbjZGCd3wapbLhba AV7svb6hiZMvw4xl06a+ADZcfoF3wGtVhYQF20HjX0mEJVIKZl/73BJKBoDTv18lssB27f8O hQBUADtGyUaHMaxEKVYwR//7s5CY6GqwcQhOvg1gbHJe1AEwHugAkIcLtwiqDb6hNgI5Hf81 o4oJVmmiGLYDSNbzy8btXw2JWb8khTpY7O7p6i6VSt0935GKhVsFMykFchsyjFYzkQyjZFQv 9jAe3z4RI6V763fqfzYkjOZLzrddiMOUP/3R9LZtwr1tewIDRZdU0ysB45/IpoNc5lr4XiV5 /ICBDC8Hh7bjEbGdXQUTD+OdEtUviXxzXIqGMr5vmlxYTom1HtavNuvEs4ElxwSta1MBduN3 RAdH/Ny6D+XKmZBXRlWX61NPpHseOIt9k/spW1fAStLKLvbNBx901nCXSotiQ5srg2Sl7yZ/ dWhYP1v4d8OzgcOvpd1L3H7XLv7+W/Uf2ZTUV9BJQXELO76Yxrr03atU4ultj4t2Fm/V1g32 2cj6/W8mHQn1T+g9PvdxB82pLZu0p9y+HNAZorwHTx7YvxStM5gO6wP1i7dpP/v9z4UcNpwW O+Eqlv4XIAOT35EEAAA= X-Brightmail-Tracker: H4sIAAAAAAAAAzWRe0hTYRjG+845nh2F5WmTPHZRWdnNnC2KPqPMQvSEIgVRdiFbelylTttm WRKay9RJakrpzJhNuzjLdFszL5lMl6Wphak5mEE5DEydhdmFaTrpv4f39zzv88JLoJx6bAVx VixjJGJhPA93wQxtPC+/KZ+w2C05k1vg085XKMwosKOw2pKPw7G27wDetv1G4UhrFoB/u3tR qH81DGC5+i4Gh1obENisLkRgVbUJgXeK5Qg0zY3jsNA4AKC1vxSBL8y+8N71Sgw2v3iDwb7G MhyqHlhZ8GHHLAJvZvcj8PnIVQANf1UorBmbxOBr80r4JTcbwF57h1PQarrvQxjdqabohlIL i+4drsPovu5kWqvJwWldZRr9VacEdNNQOk5X5BU50TfkEzjdkPnJiZ6ymjF6sqUfp/P0GkC/ LW9nHeAec9kVw8SfvcBI/ANPuZwZmptgJb3clzJSNYCkg8/bFcCZoMhtVP39aUQBXAgO2QQo U98PsAg8qAf2dnRRc6mq2VHWokmOUJ8fTcwDgsBJX6prjliYu5H1KDUlz3VsQslvKNU984G1 kOaSkDKO9Tg0RvpQyqYubCHMJgOoZyP8xQIvqrq21VHmTO6kWp/ZHEdw5i2WQRteAJaWgyUa 4MEkSRNECdGCJIGYuciXChOkyWIRPzoxQQscv9204TkYVs3yjQAhgBFQBMpzY2v1+2M57Bjh pcuMJDFKkhzPSI1gJYHx3NmCkjsxHFIklDFxDJPESP5ThHBekY6I/Jf5ufF+iCLOKVIEj82D T9ALJ9qe/JEpS9DmK3KD5+8Dobe7Zq/8Gvw4A6a577P7f2X15DWfCNDVueamDmTLjv8s1uxy PvnOpI9TedQdjlOvMm5rV4dLOu2l+uOna26Vb3RrKQu3r/UvCjDnrw/2xL4dsZqITK2Bq9AJ 2gonePXLx1VLfN3zD8q4NQfZhzuepnZc21FVu9lHNnqE0CpSNtqie89vPvrOe2uAa8ia5aGa KLNYlujXYtGLigfylcesnl45JXt7ggMjdjbakoPWGOAhDNmd1phyPuv7eOOnHTPL1iuu+nEg Oo1Gev/RWU7tyYjih9QaRpWlWesiK3iY9IxQsAmVSIX/ACP3pNxKAwAA X-CMS-MailID: 20240520102906epcas5p15b5a0b3c8edd0bf3073030a792a328bb X-Msg-Generator: CA Content-Type: text/plain; charset="utf-8" X-Sendblock-Type: REQ_APPROVE CMS-TYPE: 105P DLP-Filter: Pass X-CFilter-Loop: Reflected X-CMS-RootMailID: 20240520102906epcas5p15b5a0b3c8edd0bf3073030a792a328bb References: <20240520102033.9361-1-nj.shetty@samsung.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: For the devices which does not support copy, copy emulation is added. It is required for in-kernel users like fabrics, where file descriptor is not available and hence they can't use copy_file_range. Copy-emulation is implemented by reading from source into memory and writing to the corresponding destination. At present in kernel user of emulation is fabrics. Signed-off-by: Nitesh Shetty Signed-off-by: Vincent Fu Signed-off-by: Anuj Gupta --- block/blk-lib.c | 223 +++++++++++++++++++++++++++++++++++++++++ include/linux/blkdev.h | 4 + 2 files changed, 227 insertions(+) diff --git a/block/blk-lib.c b/block/blk-lib.c index e83461abb581..e0dd17f42c8e 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -26,6 +26,20 @@ struct blkdev_copy_offload_io { loff_t offset; }; +/* Keeps track of single outstanding copy emulation IO */ +struct blkdev_copy_emulation_io { + struct blkdev_copy_io *cio; + struct work_struct emulation_work; + void *buf; + ssize_t buf_len; + loff_t pos_in; + loff_t pos_out; + ssize_t len; + struct block_device *bdev_in; + struct block_device *bdev_out; + gfp_t gfp; +}; + static sector_t bio_discard_limit(struct block_device *bdev, sector_t sector) { unsigned int discard_granularity = bdev_discard_granularity(bdev); @@ -307,6 +321,215 @@ ssize_t blkdev_copy_offload(struct block_device *bdev, loff_t pos_in, } EXPORT_SYMBOL_GPL(blkdev_copy_offload); +static void *blkdev_copy_alloc_buf(ssize_t req_size, ssize_t *alloc_size, + gfp_t gfp) +{ + int min_size = PAGE_SIZE; + char *buf; + + while (req_size >= min_size) { + buf = kvmalloc(req_size, gfp); + if (buf) { + *alloc_size = req_size; + return buf; + } + req_size >>= 1; + } + + return NULL; +} + +static struct bio *bio_map_buf(void *data, unsigned int len, gfp_t gfp) +{ + unsigned long kaddr = (unsigned long)data; + unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT; + unsigned long start = kaddr >> PAGE_SHIFT; + const int nr_pages = end - start; + bool is_vmalloc = is_vmalloc_addr(data); + struct page *page; + int offset, i; + struct bio *bio; + + bio = bio_kmalloc(nr_pages, gfp); + if (!bio) + return ERR_PTR(-ENOMEM); + bio_init(bio, NULL, bio->bi_inline_vecs, nr_pages, 0); + + if (is_vmalloc) { + flush_kernel_vmap_range(data, len); + bio->bi_private = data; + } + + offset = offset_in_page(kaddr); + for (i = 0; i < nr_pages; i++) { + unsigned int bytes = PAGE_SIZE - offset; + + if (len <= 0) + break; + + if (bytes > len) + bytes = len; + + if (!is_vmalloc) + page = virt_to_page(data); + else + page = vmalloc_to_page(data); + if (bio_add_page(bio, page, bytes, offset) < bytes) { + /* we don't support partial mappings */ + bio_uninit(bio); + kfree(bio); + return ERR_PTR(-EINVAL); + } + + data += bytes; + len -= bytes; + offset = 0; + } + + return bio; +} + +static void blkdev_copy_emulation_work(struct work_struct *work) +{ + struct blkdev_copy_emulation_io *emulation_io = container_of(work, + struct blkdev_copy_emulation_io, emulation_work); + struct blkdev_copy_io *cio = emulation_io->cio; + struct bio *read_bio, *write_bio; + loff_t pos_in = emulation_io->pos_in, pos_out = emulation_io->pos_out; + ssize_t rem, chunk; + int ret = 0; + + for (rem = emulation_io->len; rem > 0; rem -= chunk) { + chunk = min_t(int, emulation_io->buf_len, rem); + + read_bio = bio_map_buf(emulation_io->buf, + emulation_io->buf_len, + emulation_io->gfp); + if (IS_ERR(read_bio)) { + ret = PTR_ERR(read_bio); + break; + } + read_bio->bi_opf = REQ_OP_READ | REQ_SYNC; + bio_set_dev(read_bio, emulation_io->bdev_in); + read_bio->bi_iter.bi_sector = pos_in >> SECTOR_SHIFT; + read_bio->bi_iter.bi_size = chunk; + ret = submit_bio_wait(read_bio); + kfree(read_bio); + if (ret) + break; + + write_bio = bio_map_buf(emulation_io->buf, + emulation_io->buf_len, + emulation_io->gfp); + if (IS_ERR(write_bio)) { + ret = PTR_ERR(write_bio); + break; + } + write_bio->bi_opf = REQ_OP_WRITE | REQ_SYNC; + bio_set_dev(write_bio, emulation_io->bdev_out); + write_bio->bi_iter.bi_sector = pos_out >> SECTOR_SHIFT; + write_bio->bi_iter.bi_size = chunk; + ret = submit_bio_wait(write_bio); + kfree(write_bio); + if (ret) + break; + + pos_in += chunk; + pos_out += chunk; + } + cio->status = ret; + kvfree(emulation_io->buf); + kfree(emulation_io); + blkdev_copy_endio(cio); +} + +static inline ssize_t queue_max_hw_bytes(struct request_queue *q) +{ + return min_t(ssize_t, queue_max_hw_sectors(q) << SECTOR_SHIFT, + queue_max_segments(q) << PAGE_SHIFT); +} +/* + * @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, + * 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: + * If native copy offload feature is absent, caller can use this function + * to perform copy. + * We store information required to perform the copy along with temporary + * buffer allocation. We async punt copy emulation to a worker. And worker + * performs copy in 2 steps. + * 1. Read data from source to temporary buffer + * 2. Write data to destination from temporary buffer + */ +ssize_t blkdev_copy_emulation(struct block_device *bdev_in, loff_t pos_in, + struct block_device *bdev_out, loff_t pos_out, + size_t len, void (*endio)(void *, int, ssize_t), + void *private, gfp_t gfp) +{ + struct request_queue *in = bdev_get_queue(bdev_in); + struct request_queue *out = bdev_get_queue(bdev_out); + struct blkdev_copy_emulation_io *emulation_io; + struct blkdev_copy_io *cio; + ssize_t ret; + size_t max_hw_bytes = min(queue_max_hw_bytes(in), + queue_max_hw_bytes(out)); + + ret = blkdev_copy_sanity_check(bdev_in, pos_in, bdev_out, pos_out, len); + if (ret) + return ret; + + cio = kzalloc(sizeof(*cio), gfp); + if (!cio) + return -ENOMEM; + + cio->waiter = current; + cio->copied = len; + cio->endio = endio; + cio->private = private; + + emulation_io = kzalloc(sizeof(*emulation_io), gfp); + if (!emulation_io) + goto err_free_cio; + emulation_io->cio = cio; + INIT_WORK(&emulation_io->emulation_work, blkdev_copy_emulation_work); + emulation_io->pos_in = pos_in; + emulation_io->pos_out = pos_out; + emulation_io->len = len; + emulation_io->bdev_in = bdev_in; + emulation_io->bdev_out = bdev_out; + emulation_io->gfp = gfp; + + emulation_io->buf = blkdev_copy_alloc_buf(min(max_hw_bytes, len), + &emulation_io->buf_len, gfp); + if (!emulation_io->buf) + goto err_free_emulation_io; + + schedule_work(&emulation_io->emulation_work); + + if (cio->endio) + return -EIOCBQUEUED; + + return blkdev_copy_wait_for_completion_io(cio); + +err_free_emulation_io: + kfree(emulation_io); +err_free_cio: + kfree(cio); + return -ENOMEM; +} +EXPORT_SYMBOL_GPL(blkdev_copy_emulation); + 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 3b88dcd5c433..8b1edb46880a 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1083,6 +1083,10 @@ 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); +ssize_t blkdev_copy_emulation(struct block_device *bdev_in, loff_t pos_in, + struct block_device *bdev_out, loff_t pos_out, + size_t len, void (*endio)(void *, int, ssize_t), + void *private, gfp_t gfp); #define BLKDEV_ZERO_NOUNMAP (1 << 0) /* do not free blocks */ #define BLKDEV_ZERO_NOFALLBACK (1 << 1) /* don't write explicit zeroes */ -- 2.17.1