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authorJens Axboe <axboe@kernel.dk>2019-12-18 09:50:26 -0700
committerJens Axboe <axboe@kernel.dk>2020-01-20 17:03:59 -0700
commitd3656344fea0339fb0365c8df4d2beba4e0089cd (patch)
tree088de11b0e4b91c33ed3f449def3278a827b4a01
parentadd7b6b85a4dfa89283834d181e87ea2144b9028 (diff)
io_uring: add lookup table for various opcode needs
We currently have various switch statements that check if an opcode needs a file, mm, etc. These are hard to keep in sync as opcodes are added. Add a struct io_op_def that holds all of this information, so we have just one spot to update when opcodes are added. This also enables us to NOT allocate req->io if a deferred command doesn't need it, and corrects some mistakes we had in terms of what commands need mm context. Signed-off-by: Jens Axboe <axboe@kernel.dk>
-rw-r--r--fs/io_uring.c208
1 files changed, 155 insertions, 53 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c
index b086a2dc47e2..244aaccbc82b 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -516,6 +516,135 @@ struct io_submit_state {
unsigned int ios_left;
};
+struct io_op_def {
+ /* needs req->io allocated for deferral/async */
+ unsigned async_ctx : 1;
+ /* needs current->mm setup, does mm access */
+ unsigned needs_mm : 1;
+ /* needs req->file assigned */
+ unsigned needs_file : 1;
+ /* needs req->file assigned IFF fd is >= 0 */
+ unsigned fd_non_neg : 1;
+ /* hash wq insertion if file is a regular file */
+ unsigned hash_reg_file : 1;
+ /* unbound wq insertion if file is a non-regular file */
+ unsigned unbound_nonreg_file : 1;
+};
+
+static const struct io_op_def io_op_defs[] = {
+ {
+ /* IORING_OP_NOP */
+ },
+ {
+ /* IORING_OP_READV */
+ .async_ctx = 1,
+ .needs_mm = 1,
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ {
+ /* IORING_OP_WRITEV */
+ .async_ctx = 1,
+ .needs_mm = 1,
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ {
+ /* IORING_OP_FSYNC */
+ .needs_file = 1,
+ },
+ {
+ /* IORING_OP_READ_FIXED */
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ {
+ /* IORING_OP_WRITE_FIXED */
+ .needs_file = 1,
+ .hash_reg_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ {
+ /* IORING_OP_POLL_ADD */
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ {
+ /* IORING_OP_POLL_REMOVE */
+ },
+ {
+ /* IORING_OP_SYNC_FILE_RANGE */
+ .needs_file = 1,
+ },
+ {
+ /* IORING_OP_SENDMSG */
+ .async_ctx = 1,
+ .needs_mm = 1,
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ {
+ /* IORING_OP_RECVMSG */
+ .async_ctx = 1,
+ .needs_mm = 1,
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ {
+ /* IORING_OP_TIMEOUT */
+ .async_ctx = 1,
+ .needs_mm = 1,
+ },
+ {
+ /* IORING_OP_TIMEOUT_REMOVE */
+ },
+ {
+ /* IORING_OP_ACCEPT */
+ .needs_mm = 1,
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ {
+ /* IORING_OP_ASYNC_CANCEL */
+ },
+ {
+ /* IORING_OP_LINK_TIMEOUT */
+ .async_ctx = 1,
+ .needs_mm = 1,
+ },
+ {
+ /* IORING_OP_CONNECT */
+ .async_ctx = 1,
+ .needs_mm = 1,
+ .needs_file = 1,
+ .unbound_nonreg_file = 1,
+ },
+ {
+ /* IORING_OP_FALLOCATE */
+ .needs_file = 1,
+ },
+ {
+ /* IORING_OP_OPENAT */
+ .needs_file = 1,
+ .fd_non_neg = 1,
+ },
+ {
+ /* IORING_OP_CLOSE */
+ .needs_file = 1,
+ },
+ {
+ /* IORING_OP_FILES_UPDATE */
+ .needs_mm = 1,
+ },
+ {
+ /* IORING_OP_STATX */
+ .needs_mm = 1,
+ .needs_file = 1,
+ .fd_non_neg = 1,
+ },
+};
+
static void io_wq_submit_work(struct io_wq_work **workptr);
static void io_cqring_fill_event(struct io_kiocb *req, long res);
static void io_put_req(struct io_kiocb *req);
@@ -671,41 +800,20 @@ static void __io_commit_cqring(struct io_ring_ctx *ctx)
}
}
-static inline bool io_req_needs_user(struct io_kiocb *req)
-{
- return !(req->opcode == IORING_OP_READ_FIXED ||
- req->opcode == IORING_OP_WRITE_FIXED);
-}
-
static inline bool io_prep_async_work(struct io_kiocb *req,
struct io_kiocb **link)
{
+ const struct io_op_def *def = &io_op_defs[req->opcode];
bool do_hashed = false;
- switch (req->opcode) {
- case IORING_OP_WRITEV:
- case IORING_OP_WRITE_FIXED:
- /* only regular files should be hashed for writes */
- if (req->flags & REQ_F_ISREG)
+ if (req->flags & REQ_F_ISREG) {
+ if (def->hash_reg_file)
do_hashed = true;
- /* fall-through */
- case IORING_OP_READV:
- case IORING_OP_READ_FIXED:
- case IORING_OP_SENDMSG:
- case IORING_OP_RECVMSG:
- case IORING_OP_ACCEPT:
- case IORING_OP_POLL_ADD:
- case IORING_OP_CONNECT:
- /*
- * We know REQ_F_ISREG is not set on some of these
- * opcodes, but this enables us to keep the check in
- * just one place.
- */
- if (!(req->flags & REQ_F_ISREG))
+ } else {
+ if (def->unbound_nonreg_file)
req->work.flags |= IO_WQ_WORK_UNBOUND;
- break;
}
- if (io_req_needs_user(req))
+ if (def->needs_mm)
req->work.flags |= IO_WQ_WORK_NEEDS_USER;
*link = io_prep_linked_timeout(req);
@@ -1826,6 +1934,8 @@ static void io_req_map_rw(struct io_kiocb *req, ssize_t io_size,
static int io_alloc_async_ctx(struct io_kiocb *req)
{
+ if (!io_op_defs[req->opcode].async_ctx)
+ return 0;
req->io = kmalloc(sizeof(*req->io), GFP_KERNEL);
return req->io == NULL;
}
@@ -3765,29 +3875,13 @@ static void io_wq_submit_work(struct io_wq_work **workptr)
io_wq_assign_next(workptr, nxt);
}
-static bool io_req_op_valid(int op)
-{
- return op >= IORING_OP_NOP && op < IORING_OP_LAST;
-}
-
static int io_req_needs_file(struct io_kiocb *req, int fd)
{
- switch (req->opcode) {
- case IORING_OP_NOP:
- case IORING_OP_POLL_REMOVE:
- case IORING_OP_TIMEOUT:
- case IORING_OP_TIMEOUT_REMOVE:
- case IORING_OP_ASYNC_CANCEL:
- case IORING_OP_LINK_TIMEOUT:
+ if (!io_op_defs[req->opcode].needs_file)
return 0;
- case IORING_OP_OPENAT:
- case IORING_OP_STATX:
- return fd != -1;
- default:
- if (io_req_op_valid(req->opcode))
- return 1;
- return -EINVAL;
- }
+ if (fd == -1 && io_op_defs[req->opcode].fd_non_neg)
+ return 0;
+ return 1;
}
static inline struct file *io_file_from_index(struct io_ring_ctx *ctx,
@@ -3804,7 +3898,7 @@ static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
{
struct io_ring_ctx *ctx = req->ctx;
unsigned flags;
- int fd, ret;
+ int fd;
flags = READ_ONCE(sqe->flags);
fd = READ_ONCE(sqe->fd);
@@ -3812,9 +3906,8 @@ static int io_req_set_file(struct io_submit_state *state, struct io_kiocb *req,
if (flags & IOSQE_IO_DRAIN)
req->flags |= REQ_F_IO_DRAIN;
- ret = io_req_needs_file(req, fd);
- if (ret <= 0)
- return ret;
+ if (!io_req_needs_file(req, fd))
+ return 0;
if (flags & IOSQE_FIXED_FILE) {
if (unlikely(!ctx->file_data ||
@@ -4240,7 +4333,16 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
break;
}
- if (io_req_needs_user(req) && !*mm) {
+ /* will complete beyond this point, count as submitted */
+ submitted++;
+
+ if (unlikely(req->opcode >= IORING_OP_LAST)) {
+ io_cqring_add_event(req, -EINVAL);
+ io_double_put_req(req);
+ break;
+ }
+
+ if (io_op_defs[req->opcode].needs_mm && !*mm) {
mm_fault = mm_fault || !mmget_not_zero(ctx->sqo_mm);
if (!mm_fault) {
use_mm(ctx->sqo_mm);
@@ -4248,7 +4350,6 @@ static int io_submit_sqes(struct io_ring_ctx *ctx, unsigned int nr,
}
}
- submitted++;
req->ring_file = ring_file;
req->ring_fd = ring_fd;
req->has_user = *mm != NULL;
@@ -6104,6 +6205,7 @@ out_fput:
static int __init io_uring_init(void)
{
+ BUILD_BUG_ON(ARRAY_SIZE(io_op_defs) != IORING_OP_LAST);
req_cachep = KMEM_CACHE(io_kiocb, SLAB_HWCACHE_ALIGN | SLAB_PANIC);
return 0;
};