[PATCH v9 06/11] io_uring: introduce attributes for read/write and PI support
Anuj Gupta
anuj20.g at samsung.com
Thu Nov 14 02:45:12 PST 2024
Add the ability to pass additional attributes along with read/write.
Application can populate an array of 'struct io_uring_attr_vec' and pass
its address using the SQE field:
__u64 attr_vec_addr;
Along with number of attributes using:
__u8 nr_attr_indirect;
Overall 16 attributes are allowed and currently one attribute
'ATTR_TYPE_PI' is supported.
With PI attribute, userspace can pass following information:
- flags: integrity check flags IO_INTEGRITY_CHK_{GUARD/APPTAG/REFTAG}
- len: length of PI/metadata buffer
- addr: address of metadata buffer
- seed: seed value for reftag remapping
- app_tag: application defined 16b value
Process this information to prepare uio_meta_descriptor and pass it down
using kiocb->private.
PI attribute is supported only for direct IO. Also, vectored read/write
operations are not supported with PI currently.
Signed-off-by: Anuj Gupta <anuj20.g at samsung.com>
Signed-off-by: Kanchan Joshi <joshi.k at samsung.com>
---
include/uapi/linux/io_uring.h | 29 ++++++++
io_uring/io_uring.c | 1 +
io_uring/rw.c | 128 +++++++++++++++++++++++++++++++++-
io_uring/rw.h | 14 +++-
4 files changed, 169 insertions(+), 3 deletions(-)
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 5d08435b95a8..2e6808f6ba28 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -92,12 +92,18 @@ struct io_uring_sqe {
__u16 addr_len;
__u16 __pad3[1];
};
+ struct {
+ /* number of elements in the attribute vector */
+ __u8 nr_attr_indirect;
+ __u8 __pad4[3];
+ };
};
union {
struct {
__u64 addr3;
__u64 __pad2[1];
};
+ __u64 attr_vec_addr;
__u64 optval;
/*
* If the ring is initialized with IORING_SETUP_SQE128, then
@@ -107,6 +113,29 @@ struct io_uring_sqe {
};
};
+
+/* Attributes to be passed with read/write */
+enum io_uring_attr_type {
+ ATTR_TYPE_PI,
+ /* max supported attributes */
+ ATTR_TYPE_LAST = 16,
+};
+
+struct io_uring_attr_vec {
+ enum io_uring_attr_type type;
+ __u64 addr;
+};
+
+/* PI attribute information */
+struct io_uring_attr_pi {
+ __u16 flags;
+ __u16 app_tag;
+ __u32 len;
+ __u64 addr;
+ __u64 seed;
+ __u64 rsvd;
+};
+
/*
* If sqe->file_index is set to this for opcodes that instantiate a new
* direct descriptor (like openat/openat2/accept), then io_uring will allocate
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index bd71782057de..e32dd118d7c8 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -3867,6 +3867,7 @@ static int __init io_uring_init(void)
BUILD_BUG_SQE_ELEM(44, __u32, file_index);
BUILD_BUG_SQE_ELEM(44, __u16, addr_len);
BUILD_BUG_SQE_ELEM(46, __u16, __pad3[0]);
+ BUILD_BUG_SQE_ELEM(44, __u8, nr_attr_indirect);
BUILD_BUG_SQE_ELEM(48, __u64, addr3);
BUILD_BUG_SQE_ELEM_SIZE(48, 0, cmd);
BUILD_BUG_SQE_ELEM(56, __u64, __pad2);
diff --git a/io_uring/rw.c b/io_uring/rw.c
index cce8bc2ecd3f..93d7451b9370 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -257,11 +257,98 @@ static int io_prep_rw_setup(struct io_kiocb *req, int ddir, bool do_import)
return 0;
}
+static inline void io_meta_save_state(struct io_async_rw *io)
+{
+ io->meta_state.seed = io->meta.seed;
+ iov_iter_save_state(&io->meta.iter, &io->meta_state.iter_meta);
+}
+
+static inline void io_meta_restore(struct io_async_rw *io)
+{
+ io->meta.seed = io->meta_state.seed;
+ iov_iter_restore(&io->meta.iter, &io->meta_state.iter_meta);
+}
+
+static int io_prep_rw_pi(struct io_kiocb *req, struct io_rw *rw, int ddir,
+ const struct io_uring_attr_pi *pi_attr)
+{
+ const struct io_issue_def *def;
+ struct io_async_rw *io;
+ int ret;
+
+ if (READ_ONCE(pi_attr->rsvd))
+ return -EINVAL;
+
+ def = &io_issue_defs[req->opcode];
+ if (def->vectored)
+ return -EOPNOTSUPP;
+
+ io = req->async_data;
+ io->meta.flags = READ_ONCE(pi_attr->flags);
+ io->meta.app_tag = READ_ONCE(pi_attr->app_tag);
+ io->meta.seed = READ_ONCE(pi_attr->seed);
+ ret = import_ubuf(ddir, u64_to_user_ptr(READ_ONCE(pi_attr->addr)),
+ READ_ONCE(pi_attr->len), &io->meta.iter);
+ if (unlikely(ret < 0))
+ return ret;
+ rw->kiocb.ki_flags |= IOCB_HAS_METADATA;
+ io_meta_save_state(io);
+ return ret;
+}
+
+
+static inline int io_prep_pi_indirect(struct io_kiocb *req, struct io_rw *rw,
+ int ddir, u64 pi_attr_addr)
+{
+ struct io_uring_attr_pi pi_attr;
+
+ if (copy_from_user(&pi_attr, (void __user *)pi_attr_addr, sizeof(pi_attr)))
+ return -EFAULT;
+ return io_prep_rw_pi(req, rw, ddir, &pi_attr);
+}
+
+static int io_prep_attr_vec(struct io_kiocb *req, struct io_rw *rw, int ddir,
+ u64 attr_addr, u8 nr_attr)
+{
+ struct io_uring_attr_vec attr_vec[ATTR_TYPE_LAST];
+ size_t attr_vec_size = sizeof(struct io_uring_attr_vec) * nr_attr;
+ u8 dup[ATTR_TYPE_LAST] = {0};
+ enum io_uring_attr_type t;
+ int i, ret;
+
+ if (nr_attr > ATTR_TYPE_LAST)
+ return -EINVAL;
+ if (copy_from_user(attr_vec, (void __user *)attr_addr, attr_vec_size))
+ return -EFAULT;
+
+ for (i = 0; i < nr_attr; i++) {
+ t = attr_vec[i].type;
+ if (t >= ATTR_TYPE_LAST)
+ return -EINVAL;
+ /* allow each attribute only once */
+ if (dup[ATTR_TYPE_PI])
+ return -EBUSY;
+ dup[ATTR_TYPE_PI] = 1;
+
+ switch (t) {
+ case ATTR_TYPE_PI:
+ ret = io_prep_pi_indirect(req, rw, ddir, attr_vec[i].addr);
+ break;
+ default:
+ ret = -EOPNOTSUPP;
+ }
+ if (unlikely(ret))
+ return ret;
+ }
+ return 0;
+}
+
static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
int ddir, bool do_import)
{
struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
unsigned ioprio;
+ u8 nr_attr_indirect;
int ret;
rw->kiocb.ki_pos = READ_ONCE(sqe->off);
@@ -279,11 +366,29 @@ static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe,
rw->kiocb.ki_ioprio = get_current_ioprio();
}
rw->kiocb.dio_complete = NULL;
+ rw->kiocb.ki_flags = 0;
rw->addr = READ_ONCE(sqe->addr);
rw->len = READ_ONCE(sqe->len);
rw->flags = READ_ONCE(sqe->rw_flags);
- return io_prep_rw_setup(req, ddir, do_import);
+ ret = io_prep_rw_setup(req, ddir, do_import);
+
+ if (unlikely(ret))
+ return ret;
+
+ nr_attr_indirect = READ_ONCE(sqe->nr_attr_indirect);
+ if (nr_attr_indirect) {
+ u64 attr_vec_usr_addr = READ_ONCE(sqe->attr_vec_addr);
+
+ if (READ_ONCE(sqe->__pad4[0]) || READ_ONCE(sqe->__pad4[1]) ||
+ READ_ONCE(sqe->__pad4[2]))
+ return -EINVAL;
+
+ ret = io_prep_attr_vec(req, rw, ddir, attr_vec_usr_addr,
+ nr_attr_indirect);
+ }
+
+ return ret;
}
int io_prep_read(struct io_kiocb *req, const struct io_uring_sqe *sqe)
@@ -409,7 +514,10 @@ static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req)
static void io_resubmit_prep(struct io_kiocb *req)
{
struct io_async_rw *io = req->async_data;
+ struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
+ if (rw->kiocb.ki_flags & IOCB_HAS_METADATA)
+ io_meta_restore(io);
iov_iter_restore(&io->iter, &io->iter_state);
}
@@ -794,7 +902,7 @@ static int io_rw_init_file(struct io_kiocb *req, fmode_t mode, int rw_type)
if (!(req->flags & REQ_F_FIXED_FILE))
req->flags |= io_file_get_flags(file);
- kiocb->ki_flags = file->f_iocb_flags;
+ kiocb->ki_flags |= file->f_iocb_flags;
ret = kiocb_set_rw_flags(kiocb, rw->flags, rw_type);
if (unlikely(ret))
return ret;
@@ -828,6 +936,18 @@ static int io_rw_init_file(struct io_kiocb *req, fmode_t mode, int rw_type)
kiocb->ki_complete = io_complete_rw;
}
+ if (kiocb->ki_flags & IOCB_HAS_METADATA) {
+ struct io_async_rw *io = req->async_data;
+
+ /*
+ * We have a union of meta fields with wpq used for buffered-io
+ * in io_async_rw, so fail it here.
+ */
+ if (!(req->file->f_flags & O_DIRECT))
+ return -EOPNOTSUPP;
+ kiocb->private = &io->meta;
+ }
+
return 0;
}
@@ -902,6 +1022,8 @@ static int __io_read(struct io_kiocb *req, unsigned int issue_flags)
* manually if we need to.
*/
iov_iter_restore(&io->iter, &io->iter_state);
+ if (kiocb->ki_flags & IOCB_HAS_METADATA)
+ io_meta_restore(io);
do {
/*
@@ -1125,6 +1247,8 @@ int io_write(struct io_kiocb *req, unsigned int issue_flags)
} else {
ret_eagain:
iov_iter_restore(&io->iter, &io->iter_state);
+ if (kiocb->ki_flags & IOCB_HAS_METADATA)
+ io_meta_restore(io);
if (kiocb->ki_flags & IOCB_WRITE)
io_req_end_write(req);
return -EAGAIN;
diff --git a/io_uring/rw.h b/io_uring/rw.h
index 3f432dc75441..2d7656bd268d 100644
--- a/io_uring/rw.h
+++ b/io_uring/rw.h
@@ -2,6 +2,11 @@
#include <linux/pagemap.h>
+struct io_meta_state {
+ u32 seed;
+ struct iov_iter_state iter_meta;
+};
+
struct io_async_rw {
size_t bytes_done;
struct iov_iter iter;
@@ -9,7 +14,14 @@ struct io_async_rw {
struct iovec fast_iov;
struct iovec *free_iovec;
int free_iov_nr;
- struct wait_page_queue wpq;
+ /* wpq is for buffered io, while meta fields are used with direct io */
+ union {
+ struct wait_page_queue wpq;
+ struct {
+ struct uio_meta meta;
+ struct io_meta_state meta_state;
+ };
+ };
};
int io_prep_read_fixed(struct io_kiocb *req, const struct io_uring_sqe *sqe);
--
2.25.1
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