From c992fe2925d776be066d9f6cc13f9ea11d78b657 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 11 Jan 2019 09:43:02 -0700 Subject: [PATCH] io_uring: add fsync support Add a new fsync opcode, which either syncs a range if one is passed, or the whole file if the offset and length fields are both cleared to zero. A flag is provided to use fdatasync semantics, that is only force out metadata which is required to retrieve the file data, but not others like metadata. Reviewed-by: Hannes Reinecke Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- fs/io_uring.c | 54 +++++++++++++++++++++++++++++++++++++++++++ include/uapi/linux/io_uring.h | 8 ++++++- 2 files changed, 61 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index f68052290426..745413d92712 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -24,6 +24,7 @@ * data that the application could potentially modify, it remains stable. * * Copyright (C) 2018-2019 Jens Axboe + * Copyright (c) 2018-2019 Christoph Hellwig */ #include #include @@ -557,6 +558,56 @@ static int io_nop(struct io_kiocb *req, u64 user_data) return 0; } +static int io_prep_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe) +{ + int fd; + + /* Prep already done */ + if (req->rw.ki_filp) + return 0; + + if (unlikely(sqe->addr || sqe->ioprio)) + return -EINVAL; + + fd = READ_ONCE(sqe->fd); + req->rw.ki_filp = fget(fd); + if (unlikely(!req->rw.ki_filp)) + return -EBADF; + + return 0; +} + +static int io_fsync(struct io_kiocb *req, const struct io_uring_sqe *sqe, + bool force_nonblock) +{ + loff_t sqe_off = READ_ONCE(sqe->off); + loff_t sqe_len = READ_ONCE(sqe->len); + loff_t end = sqe_off + sqe_len; + unsigned fsync_flags; + int ret; + + fsync_flags = READ_ONCE(sqe->fsync_flags); + if (unlikely(fsync_flags & ~IORING_FSYNC_DATASYNC)) + return -EINVAL; + + ret = io_prep_fsync(req, sqe); + if (ret) + return ret; + + /* fsync always requires a blocking context */ + if (force_nonblock) + return -EAGAIN; + + ret = vfs_fsync_range(req->rw.ki_filp, sqe_off, + end > 0 ? end : LLONG_MAX, + fsync_flags & IORING_FSYNC_DATASYNC); + + fput(req->rw.ki_filp); + io_cqring_add_event(req->ctx, sqe->user_data, ret, 0); + io_free_req(req); + return 0; +} + static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, const struct sqe_submit *s, bool force_nonblock) { @@ -578,6 +629,9 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req, case IORING_OP_WRITEV: ret = io_write(req, s, force_nonblock); break; + case IORING_OP_FSYNC: + ret = io_fsync(req, s->sqe, force_nonblock); + break; default: ret = -EINVAL; break; diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h index ac692823d6f4..4589d56d0b68 100644 --- a/include/uapi/linux/io_uring.h +++ b/include/uapi/linux/io_uring.h @@ -24,7 +24,7 @@ struct io_uring_sqe { __u32 len; /* buffer size or number of iovecs */ union { __kernel_rwf_t rw_flags; - __u32 __resv; + __u32 fsync_flags; }; __u64 user_data; /* data to be passed back at completion time */ __u64 __pad2[3]; @@ -33,6 +33,12 @@ struct io_uring_sqe { #define IORING_OP_NOP 0 #define IORING_OP_READV 1 #define IORING_OP_WRITEV 2 +#define IORING_OP_FSYNC 3 + +/* + * sqe->fsync_flags + */ +#define IORING_FSYNC_DATASYNC (1U << 0) /* * IO completion data structure (Completion Queue Entry) -- 2.11.0