This adds a new io_uring interface to exchange meta along with read/write. Interface: Meta information is represented using a newly introduced 'struct io_uring_meta'. Application sets up a SQE128 ring, and prepares io_uring_meta within second SQE. Application populates 'struct io_uring_meta' fields as below: * meta_type: describes type of meta that is passed. Currently one type "Integrity" is supported. * meta_flags: these are meta-type specific flags. Three flags are exposed for integrity type, namely INTEGRITY_CHK_GUARD/APPTAG/REFTAG. * meta_len: length of the meta buffer * meta_addr: address of the meta buffer * app_tag: optional application-specific 16b value; this goes along with INTEGRITY_CHK_APPTAG flag. Block path (direct IO) , NVMe and SCSI driver are modified to support this. The first three patches are required to make the user metadata split work correctly. Patch 4,5 are prep patches. Patch 6 adds the io_uring support. Patch 7 gives us unified interface for user and kernel generated integrity. Patch 8 adds the support for block direct IO, patch 9 for NVMe, and patch 10 for SCSI. Some of the design choices came from this discussion [2]. Example program on how to use the interface is appended below [3] Tree: https://github.com/SamsungDS/linux/tree/feat/pi_us_v3 Testing: has been done by modifying fio to use this interface. https://github.sec.samsung.net/DS8-MemoryOpenSource/fio/tree/feat/test-meta-v4 Changes since v2: https://lore.kernel.org/linux-block/20240626100700.3629-1-anuj20.g@xxxxxxxxxxx/ - io_uring error handling styling (Gabriel) - add documented helper to get metadata bytes from data iter (hch) - during clone specify "what flags to clone" rather than "what not to clone" (hch) - Move uio_meta defination to bio-integrity.h (hch) - Rename apptag field to app_tag (hch) - Change datatype of flags field in uio_meta to bitwise (hch) - Don't introduce BIP_USER_CHK_FOO flags (hch, martin) - Driver should rely on block layer flags instead of seeing if it is user-passthrough (hch) - update the scsi code for handling user-meta (hch, martin) Changes since v1: https://lore.kernel.org/linux-block/20240425183943.6319-1-joshi.k@xxxxxxxxxxx/ - Do not use new opcode for meta, and also add the provision to introduce new meta types beyond integrity (Pavel) - Stuff IOCB_HAS_META check in need_complete_io (Jens) - Split meta handling in NVMe into a separate handler (Keith) - Add meta handling for __blkdev_direct_IO too (Keith) - Don't inherit BIP_COPY_USER flag for cloned bio's (Christoph) - Better commit descriptions (Christoph) Changes since RFC: - modify io_uring plumbing based on recent async handling state changes - fixes/enhancements to correctly handle the split for meta buffer - add flags to specify guard/reftag/apptag checks - add support to send apptag [1] https://lore.kernel.org/linux-block/719d2e-b0e6-663c-ec38-acf939e4a04b@xxxxxxxxxx/ [2] https://lore.kernel.org/linux-block/20240705083205.2111277-1-hch@xxxxxx/ [3] #define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <string.h> #include <linux/io_uring.h> #include <linux/types.h> #include "liburing.h" /* write data/meta. read both. compare. send apptag too. * prerequisite: * unprotected xfer: format namespace with 4KB + 8b, pi_type = 0 * protected xfer: format namespace with 4KB + 8b, pi_type = 1 */ #define DATA_LEN 4096 #define META_LEN 8 struct t10_pi_tuple { __be16 guard; __be16 apptag; __be32 reftag; }; int main(int argc, char *argv[]) { struct io_uring ring; struct io_uring_sqe *sqe = NULL; struct io_uring_cqe *cqe = NULL; void *wdb,*rdb; char wmb[META_LEN], rmb[META_LEN]; char *data_str = "data buffer"; char *meta_str = "meta"; int fd, ret, blksize; struct stat fstat; unsigned long long offset = DATA_LEN; struct t10_pi_tuple *pi; struct io_uring_meta *md; if (argc != 2) { fprintf(stderr, "Usage: %s <block-device>", argv[0]); return 1; }; if (stat(argv[1], &fstat) == 0) { blksize = (int)fstat.st_blksize; } else { perror("stat"); return 1; } if (posix_memalign(&wdb, blksize, DATA_LEN)) { perror("posix_memalign failed"); return 1; } if (posix_memalign(&rdb, blksize, DATA_LEN)) { perror("posix_memalign failed"); return 1; } strcpy(wdb, data_str); strcpy(wmb, meta_str); fd = open(argv[1], O_RDWR | O_DIRECT); if (fd < 0) { printf("Error in opening device\n"); return 0; } ret = io_uring_queue_init(8, &ring, IORING_SETUP_SQE128); if (ret) { fprintf(stderr, "ring setup failed: %d\n", ret); return 1; } /* write data + meta-buffer to device */ sqe = io_uring_get_sqe(&ring); if (!sqe) { fprintf(stderr, "get sqe failed\n"); return 1; } io_uring_prep_write(sqe, fd, wdb, DATA_LEN, offset); md = (struct io_uring_meta *) sqe->big_sqe_cmd; md->meta_type = META_TYPE_INTEGRITY; md->meta_addr = (__u64)wmb; md->meta_len = META_LEN; /* flags to ask for guard/reftag/apptag*/ md->meta_flags = INTEGRITY_CHK_APPTAG; md->app_tag = 0x1234; pi = (struct t10_pi_tuple *)wmb; pi->apptag = 0x3412; ret = io_uring_submit(&ring); if (ret <= 0) { fprintf(stderr, "sqe submit failed: %d\n", ret); return 1; } ret = io_uring_wait_cqe(&ring, &cqe); if (!cqe) { fprintf(stderr, "cqe is NULL :%d\n", ret); return 1; } if (cqe->res < 0) { fprintf(stderr, "write cqe failure: %d", cqe->res); return 1; } io_uring_cqe_seen(&ring, cqe); /* read data + meta-buffer back from device */ sqe = io_uring_get_sqe(&ring); if (!sqe) { fprintf(stderr, "get sqe failed\n"); return 1; } io_uring_prep_read(sqe, fd, rdb, DATA_LEN, offset); md = (struct io_uring_meta *) sqe->big_sqe_cmd; md->meta_type = META_TYPE_INTEGRITY; md->meta_addr = (__u64)rmb; md->meta_len = META_LEN; md->meta_flags = INTEGRITY_CHK_APPTAG; md->app_tag = 0x1234; ret = io_uring_submit(&ring); if (ret <= 0) { fprintf(stderr, "sqe submit failed: %d\n", ret); return 1; } ret = io_uring_wait_cqe(&ring, &cqe); if (!cqe) { fprintf(stderr, "cqe is NULL :%d\n", ret); return 1; } if (cqe->res < 0) { fprintf(stderr, "read cqe failure: %d", cqe->res); return 1; } io_uring_cqe_seen(&ring, cqe); if (strncmp(wmb, rmb, META_LEN)) printf("Failure: meta mismatch!, wmb=%s, rmb=%s\n", wmb, rmb); if (strncmp(wdb, rdb, DATA_LEN)) printf("Failure: data mismatch!\n"); io_uring_queue_exit(&ring); free(rdb); free(wdb); return 0; } Anuj Gupta (7): block: define set of integrity flags to be inherited by cloned bip block: introduce a helper to determine metadata bytes from data iter block: handle split correctly for user meta bounce buffer block: modify bio_integrity_map_user to accept iov_iter as argument io_uring/rw: add support to send meta along with read/write block,nvme: introduce BIP_CHECK_GUARD/REFTAG/APPTAG bip_flags scsi: add support for user-meta interface Kanchan Joshi (3): block: define meta io descriptor block: add support to pass user meta buffer nvme: add handling for app_tag block/bio-integrity.c | 71 ++++++++++++++++++++++++++++++----- block/fops.c | 25 ++++++++++++ block/t10-pi.c | 6 +++ drivers/nvme/host/core.c | 24 +++++++----- drivers/nvme/host/ioctl.c | 11 +++++- drivers/scsi/sd.c | 25 +++++++++++- drivers/scsi/sd_dif.c | 2 +- include/linux/bio-integrity.h | 33 ++++++++++++++-- include/linux/blk-integrity.h | 17 +++++++++ include/linux/fs.h | 1 + include/uapi/linux/io_uring.h | 32 ++++++++++++++++ io_uring/io_uring.c | 6 +++ io_uring/rw.c | 70 ++++++++++++++++++++++++++++++++-- io_uring/rw.h | 10 ++++- 14 files changed, 302 insertions(+), 31 deletions(-) -- 2.25.1
