#include <linux/init.h>
#include <linux/errno.h>
#include <linux/syscalls.h>
-#include <linux/compat.h>
#include <net/compat.h>
#include <linux/refcount.h>
#include <linux/uio.h>
#include <linux/mman.h>
#include <linux/percpu.h>
#include <linux/slab.h>
-#include <linux/blk-mq.h>
#include <linux/bvec.h>
#include <linux/net.h>
#include <net/sock.h>
#include <linux/sched/mm.h>
#include <linux/uaccess.h>
#include <linux/nospec.h>
-#include <linux/sizes.h>
#include <linux/highmem.h>
#include <linux/fsnotify.h>
#include <linux/fadvise.h>
-#include <linux/eventpoll.h>
#include <linux/task_work.h>
-#include <linux/pagemap.h>
#include <linux/io_uring.h>
#include <linux/audit.h>
#include <linux/security.h>
#include "timeout.h"
#include "poll.h"
#include "cancel.h"
+#include "rw.h"
#define IORING_MAX_ENTRIES 32768
#define IORING_MAX_CQ_ENTRIES (2 * IORING_MAX_ENTRIES)
#define IO_REQ_CACHE_SIZE 32
#define IO_REQ_ALLOC_BATCH 8
-/*
- * First field must be the file pointer in all the
- * iocb unions! See also 'struct kiocb' in <linux/fs.h>
- */
-struct io_rw {
- /* NOTE: kiocb has the file as the first member, so don't do it here */
- struct kiocb kiocb;
- u64 addr;
- u32 len;
- rwf_t flags;
-};
-
-struct io_rw_state {
- struct iov_iter iter;
- struct iov_iter_state iter_state;
- struct iovec fast_iov[UIO_FASTIOV];
-};
-
-struct io_async_rw {
- struct io_rw_state s;
- const struct iovec *free_iovec;
- size_t bytes_done;
- struct wait_page_queue wpq;
-};
-
enum {
IO_CHECK_CQ_OVERFLOW_BIT,
IO_CHECK_CQ_DROPPED_BIT,
static void io_clean_op(struct io_kiocb *req);
static void io_queue_sqe(struct io_kiocb *req);
-static void io_req_task_queue(struct io_kiocb *req);
static void __io_submit_flush_completions(struct io_ring_ctx *ctx);
-static int io_req_prep_async(struct io_kiocb *req);
static void io_eventfd_signal(struct io_ring_ctx *ctx);
return false;
}
-static inline bool io_req_ffs_set(struct io_kiocb *req)
-{
- return req->flags & REQ_F_FIXED_FILE;
-}
-
static inline void io_req_track_inflight(struct io_kiocb *req)
{
if (!(req->flags & REQ_F_INFLIGHT)) {
wq_list_add_tail(&req->comp_list, &state->compl_reqs);
}
-static void io_queue_iowq(struct io_kiocb *req, bool *dont_use)
+void io_queue_iowq(struct io_kiocb *req, bool *dont_use)
{
struct io_kiocb *link = io_prep_linked_timeout(req);
struct io_uring_task *tctx = req->task->io_uring;
}
}
-static void __io_commit_cqring_flush(struct io_ring_ctx *ctx)
+void __io_commit_cqring_flush(struct io_ring_ctx *ctx)
{
if (ctx->off_timeout_used || ctx->drain_active) {
spin_lock(&ctx->completion_lock);
io_eventfd_signal(ctx);
}
-static inline unsigned int __io_cqring_events(struct io_ring_ctx *ctx)
-{
- return ctx->cached_cq_tail - READ_ONCE(ctx->rings->cq.head);
-}
-
-/*
- * writes to the cq entry need to come after reading head; the
- * control dependency is enough as we're using WRITE_ONCE to
- * fill the cq entry
- */
-static noinline struct io_uring_cqe *__io_get_cqe(struct io_ring_ctx *ctx)
-{
- struct io_rings *rings = ctx->rings;
- unsigned int off = ctx->cached_cq_tail & (ctx->cq_entries - 1);
- unsigned int shift = 0;
- unsigned int free, queued, len;
-
- if (ctx->flags & IORING_SETUP_CQE32)
- shift = 1;
-
- /* userspace may cheat modifying the tail, be safe and do min */
- queued = min(__io_cqring_events(ctx), ctx->cq_entries);
- free = ctx->cq_entries - queued;
- /* we need a contiguous range, limit based on the current array offset */
- len = min(free, ctx->cq_entries - off);
- if (!len)
- return NULL;
-
- ctx->cached_cq_tail++;
- ctx->cqe_cached = &rings->cqes[off];
- ctx->cqe_sentinel = ctx->cqe_cached + len;
- ctx->cqe_cached++;
- return &rings->cqes[off << shift];
-}
-
-static inline struct io_uring_cqe *io_get_cqe(struct io_ring_ctx *ctx)
-{
- if (likely(ctx->cqe_cached < ctx->cqe_sentinel)) {
- struct io_uring_cqe *cqe = ctx->cqe_cached;
-
- if (ctx->flags & IORING_SETUP_CQE32) {
- unsigned int off = ctx->cqe_cached - ctx->rings->cqes;
-
- cqe += off;
- }
-
- ctx->cached_cq_tail++;
- ctx->cqe_cached++;
- return cqe;
- }
-
- return __io_get_cqe(ctx);
-}
-
static void io_eventfd_signal(struct io_ring_ctx *ctx)
{
struct io_ev_fd *ev_fd;
rcu_read_unlock();
}
-static inline void io_cqring_wake(struct io_ring_ctx *ctx)
-{
- /*
- * wake_up_all() may seem excessive, but io_wake_function() and
- * io_should_wake() handle the termination of the loop and only
- * wake as many waiters as we need to.
- */
- if (wq_has_sleeper(&ctx->cq_wait))
- wake_up_all(&ctx->cq_wait);
-}
-
/*
* This should only get called when at least one event has been posted.
* Some applications rely on the eventfd notification count only changing
io_cqring_wake(ctx);
}
-static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
-{
- if (unlikely(ctx->off_timeout_used || ctx->drain_active ||
- ctx->has_evfd))
- __io_commit_cqring_flush(ctx);
-
- if (ctx->flags & IORING_SETUP_SQPOLL)
- io_cqring_wake(ctx);
-}
-
/* Returns true if there are no backlogged entries after the flush */
static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force)
{
}
}
-static bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data,
- s32 res, u32 cflags, u64 extra1,
- u64 extra2)
+bool io_cqring_event_overflow(struct io_ring_ctx *ctx, u64 user_data, s32 res,
+ u32 cflags, u64 extra1, u64 extra2)
{
struct io_overflow_cqe *ocqe;
size_t ocq_size = sizeof(struct io_overflow_cqe);
return true;
}
-static inline bool __io_fill_cqe_req(struct io_ring_ctx *ctx,
- struct io_kiocb *req)
-{
- struct io_uring_cqe *cqe;
-
- if (!(ctx->flags & IORING_SETUP_CQE32)) {
- trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
- req->cqe.res, req->cqe.flags, 0, 0);
-
- /*
- * If we can't get a cq entry, userspace overflowed the
- * submission (by quite a lot). Increment the overflow count in
- * the ring.
- */
- cqe = io_get_cqe(ctx);
- if (likely(cqe)) {
- memcpy(cqe, &req->cqe, sizeof(*cqe));
- return true;
- }
-
- return io_cqring_event_overflow(ctx, req->cqe.user_data,
- req->cqe.res, req->cqe.flags,
- 0, 0);
- } else {
- u64 extra1 = 0, extra2 = 0;
-
- if (req->flags & REQ_F_CQE32_INIT) {
- extra1 = req->extra1;
- extra2 = req->extra2;
- }
-
- trace_io_uring_complete(req->ctx, req, req->cqe.user_data,
- req->cqe.res, req->cqe.flags, extra1, extra2);
-
- /*
- * If we can't get a cq entry, userspace overflowed the
- * submission (by quite a lot). Increment the overflow count in
- * the ring.
- */
- cqe = io_get_cqe(ctx);
- if (likely(cqe)) {
- memcpy(cqe, &req->cqe, sizeof(struct io_uring_cqe));
- WRITE_ONCE(cqe->big_cqe[0], extra1);
- WRITE_ONCE(cqe->big_cqe[1], extra2);
- return true;
- }
-
- return io_cqring_event_overflow(ctx, req->cqe.user_data,
- req->cqe.res, req->cqe.flags,
- extra1, extra2);
- }
-}
-
bool io_fill_cqe_aux(struct io_ring_ctx *ctx, u64 user_data, s32 res,
u32 cflags)
{
__io_req_task_work_add(req, tctx, &tctx->task_list);
}
-static void io_req_task_prio_work_add(struct io_kiocb *req)
+void io_req_task_prio_work_add(struct io_kiocb *req)
{
struct io_uring_task *tctx = req->task->io_uring;
io_req_task_work_add(req);
}
-static void io_req_task_queue(struct io_kiocb *req)
+void io_req_task_queue(struct io_kiocb *req)
{
req->io_task_work.func = io_req_task_submit;
io_req_task_work_add(req);
}
-static void io_req_task_queue_reissue(struct io_kiocb *req)
-{
- req->io_task_work.func = io_queue_iowq;
- io_req_task_work_add(req);
-}
-
void io_queue_next(struct io_kiocb *req)
{
struct io_kiocb *nxt = io_req_find_next(req);
io_req_task_queue(nxt);
}
-static void io_free_batch_list(struct io_ring_ctx *ctx,
- struct io_wq_work_node *node)
+void io_free_batch_list(struct io_ring_ctx *ctx, struct io_wq_work_node *node)
__must_hold(&ctx->uring_lock)
{
struct task_struct *task = NULL;
return __io_cqring_events(ctx);
}
-int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin)
-{
- struct io_wq_work_node *pos, *start, *prev;
- unsigned int poll_flags = BLK_POLL_NOSLEEP;
- DEFINE_IO_COMP_BATCH(iob);
- int nr_events = 0;
-
- /*
- * Only spin for completions if we don't have multiple devices hanging
- * off our complete list.
- */
- if (ctx->poll_multi_queue || force_nonspin)
- poll_flags |= BLK_POLL_ONESHOT;
-
- wq_list_for_each(pos, start, &ctx->iopoll_list) {
- struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list);
- struct io_rw *rw = io_kiocb_to_cmd(req);
- int ret;
-
- /*
- * Move completed and retryable entries to our local lists.
- * If we find a request that requires polling, break out
- * and complete those lists first, if we have entries there.
- */
- if (READ_ONCE(req->iopoll_completed))
- break;
-
- ret = rw->kiocb.ki_filp->f_op->iopoll(&rw->kiocb, &iob, poll_flags);
- if (unlikely(ret < 0))
- return ret;
- else if (ret)
- poll_flags |= BLK_POLL_ONESHOT;
-
- /* iopoll may have completed current req */
- if (!rq_list_empty(iob.req_list) ||
- READ_ONCE(req->iopoll_completed))
- break;
- }
-
- if (!rq_list_empty(iob.req_list))
- iob.complete(&iob);
- else if (!pos)
- return 0;
-
- prev = start;
- wq_list_for_each_resume(pos, prev) {
- struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list);
-
- /* order with io_complete_rw_iopoll(), e.g. ->result updates */
- if (!smp_load_acquire(&req->iopoll_completed))
- break;
- nr_events++;
- if (unlikely(req->flags & REQ_F_CQE_SKIP))
- continue;
-
- req->cqe.flags = io_put_kbuf(req, 0);
- __io_fill_cqe_req(req->ctx, req);
- }
-
- if (unlikely(!nr_events))
- return 0;
-
- io_commit_cqring(ctx);
- io_cqring_ev_posted_iopoll(ctx);
- pos = start ? start->next : ctx->iopoll_list.first;
- wq_list_cut(&ctx->iopoll_list, prev, start);
- io_free_batch_list(ctx, pos);
- return nr_events;
-}
-
/*
* We can't just wait for polled events to come to us, we have to actively
* find and complete them.
return ret;
}
-
-static void kiocb_end_write(struct io_kiocb *req)
-{
- /*
- * Tell lockdep we inherited freeze protection from submission
- * thread.
- */
- if (req->flags & REQ_F_ISREG) {
- struct super_block *sb = file_inode(req->file)->i_sb;
-
- __sb_writers_acquired(sb, SB_FREEZE_WRITE);
- sb_end_write(sb);
- }
-}
-
-#ifdef CONFIG_BLOCK
-static bool io_resubmit_prep(struct io_kiocb *req)
-{
- struct io_async_rw *io = req->async_data;
-
- if (!req_has_async_data(req))
- return !io_req_prep_async(req);
- iov_iter_restore(&io->s.iter, &io->s.iter_state);
- return true;
-}
-
-static bool io_rw_should_reissue(struct io_kiocb *req)
-{
- umode_t mode = file_inode(req->file)->i_mode;
- struct io_ring_ctx *ctx = req->ctx;
-
- if (!S_ISBLK(mode) && !S_ISREG(mode))
- return false;
- if ((req->flags & REQ_F_NOWAIT) || (io_wq_current_is_worker() &&
- !(ctx->flags & IORING_SETUP_IOPOLL)))
- return false;
- /*
- * If ref is dying, we might be running poll reap from the exit work.
- * Don't attempt to reissue from that path, just let it fail with
- * -EAGAIN.
- */
- if (percpu_ref_is_dying(&ctx->refs))
- return false;
- /*
- * Play it safe and assume not safe to re-import and reissue if we're
- * not in the original thread group (or in task context).
- */
- if (!same_thread_group(req->task, current) || !in_task())
- return false;
- return true;
-}
-#else
-static bool io_resubmit_prep(struct io_kiocb *req)
-{
- return false;
-}
-static bool io_rw_should_reissue(struct io_kiocb *req)
-{
- return false;
-}
-#endif
-
-static bool __io_complete_rw_common(struct io_kiocb *req, long res)
-{
- struct io_rw *rw = io_kiocb_to_cmd(req);
-
- if (rw->kiocb.ki_flags & IOCB_WRITE) {
- kiocb_end_write(req);
- fsnotify_modify(req->file);
- } else {
- fsnotify_access(req->file);
- }
- if (unlikely(res != req->cqe.res)) {
- if ((res == -EAGAIN || res == -EOPNOTSUPP) &&
- io_rw_should_reissue(req)) {
- req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO;
- return true;
- }
- req_set_fail(req);
- req->cqe.res = res;
- }
- return false;
-}
-
inline void io_req_task_complete(struct io_kiocb *req, bool *locked)
{
if (*locked) {
}
}
-static void __io_complete_rw(struct io_kiocb *req, long res,
- unsigned int issue_flags)
-{
- if (__io_complete_rw_common(req, res))
- return;
- io_req_set_res(req, req->cqe.res, io_put_kbuf(req, issue_flags));
- __io_req_complete(req, issue_flags);
-}
-
-static void io_complete_rw(struct kiocb *kiocb, long res)
-{
- struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb);
- struct io_kiocb *req = cmd_to_io_kiocb(rw);
-
- if (__io_complete_rw_common(req, res))
- return;
- io_req_set_res(req, res, 0);
- req->io_task_work.func = io_req_task_complete;
- io_req_task_prio_work_add(req);
-}
-
-static void io_complete_rw_iopoll(struct kiocb *kiocb, long res)
-{
- struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb);
- struct io_kiocb *req = cmd_to_io_kiocb(rw);
-
- if (kiocb->ki_flags & IOCB_WRITE)
- kiocb_end_write(req);
- if (unlikely(res != req->cqe.res)) {
- if (res == -EAGAIN && io_rw_should_reissue(req)) {
- req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO;
- return;
- }
- req->cqe.res = res;
- }
-
- /* order with io_iopoll_complete() checking ->iopoll_completed */
- smp_store_release(&req->iopoll_completed, 1);
-}
-
/*
* After the iocb has been issued, it's safe to be found on the poll list.
* Adding the kiocb to the list AFTER submission ensures that we don't
return res;
}
-static inline bool io_file_supports_nowait(struct io_kiocb *req)
-{
- return req->flags & REQ_F_SUPPORT_NOWAIT;
-}
-
-static int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe)
-{
- struct io_rw *rw = io_kiocb_to_cmd(req);
- unsigned ioprio;
- int ret;
-
- rw->kiocb.ki_pos = READ_ONCE(sqe->off);
- /* used for fixed read/write too - just read unconditionally */
- req->buf_index = READ_ONCE(sqe->buf_index);
-
- if (req->opcode == IORING_OP_READ_FIXED ||
- req->opcode == IORING_OP_WRITE_FIXED) {
- struct io_ring_ctx *ctx = req->ctx;
- u16 index;
-
- if (unlikely(req->buf_index >= ctx->nr_user_bufs))
- return -EFAULT;
- index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
- req->imu = ctx->user_bufs[index];
- io_req_set_rsrc_node(req, ctx, 0);
- }
-
- ioprio = READ_ONCE(sqe->ioprio);
- if (ioprio) {
- ret = ioprio_check_cap(ioprio);
- if (ret)
- return ret;
-
- rw->kiocb.ki_ioprio = ioprio;
- } else {
- rw->kiocb.ki_ioprio = get_current_ioprio();
- }
-
- rw->addr = READ_ONCE(sqe->addr);
- rw->len = READ_ONCE(sqe->len);
- rw->flags = READ_ONCE(sqe->rw_flags);
- return 0;
-}
-
-static void io_readv_writev_cleanup(struct io_kiocb *req)
-{
- struct io_async_rw *io = req->async_data;
-
- kfree(io->free_iovec);
-}
-
-static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
-{
- switch (ret) {
- case -EIOCBQUEUED:
- break;
- case -ERESTARTSYS:
- case -ERESTARTNOINTR:
- case -ERESTARTNOHAND:
- case -ERESTART_RESTARTBLOCK:
- /*
- * We can't just restart the syscall, since previously
- * submitted sqes may already be in progress. Just fail this
- * IO with EINTR.
- */
- ret = -EINTR;
- fallthrough;
- default:
- kiocb->ki_complete(kiocb, ret);
- }
-}
-
-static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req)
-{
- struct io_rw *rw = io_kiocb_to_cmd(req);
-
- if (rw->kiocb.ki_pos != -1)
- return &rw->kiocb.ki_pos;
-
- if (!(req->file->f_mode & FMODE_STREAM)) {
- req->flags |= REQ_F_CUR_POS;
- rw->kiocb.ki_pos = req->file->f_pos;
- return &rw->kiocb.ki_pos;
- }
-
- rw->kiocb.ki_pos = 0;
- return NULL;
-}
-
-static void kiocb_done(struct io_kiocb *req, ssize_t ret,
- unsigned int issue_flags)
-{
- struct io_async_rw *io = req->async_data;
- struct io_rw *rw = io_kiocb_to_cmd(req);
-
- /* add previously done IO, if any */
- if (req_has_async_data(req) && io->bytes_done > 0) {
- if (ret < 0)
- ret = io->bytes_done;
- else
- ret += io->bytes_done;
- }
-
- if (req->flags & REQ_F_CUR_POS)
- req->file->f_pos = rw->kiocb.ki_pos;
- if (ret >= 0 && (rw->kiocb.ki_complete == io_complete_rw))
- __io_complete_rw(req, ret, issue_flags);
- else
- io_rw_done(&rw->kiocb, ret);
-
- if (req->flags & REQ_F_REISSUE) {
- req->flags &= ~REQ_F_REISSUE;
- if (io_resubmit_prep(req))
- io_req_task_queue_reissue(req);
- else
- io_req_task_queue_fail(req, ret);
- }
-}
-
-static int __io_import_fixed(struct io_kiocb *req, int ddir,
- struct iov_iter *iter, struct io_mapped_ubuf *imu)
-{
- struct io_rw *rw = io_kiocb_to_cmd(req);
- size_t len = rw->len;
- u64 buf_end, buf_addr = rw->addr;
- size_t offset;
-
- if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end)))
- return -EFAULT;
- /* not inside the mapped region */
- if (unlikely(buf_addr < imu->ubuf || buf_end > imu->ubuf_end))
- return -EFAULT;
-
- /*
- * May not be a start of buffer, set size appropriately
- * and advance us to the beginning.
- */
- offset = buf_addr - imu->ubuf;
- iov_iter_bvec(iter, ddir, imu->bvec, imu->nr_bvecs, offset + len);
-
- if (offset) {
- /*
- * Don't use iov_iter_advance() here, as it's really slow for
- * using the latter parts of a big fixed buffer - it iterates
- * over each segment manually. We can cheat a bit here, because
- * we know that:
- *
- * 1) it's a BVEC iter, we set it up
- * 2) all bvecs are PAGE_SIZE in size, except potentially the
- * first and last bvec
- *
- * So just find our index, and adjust the iterator afterwards.
- * If the offset is within the first bvec (or the whole first
- * bvec, just use iov_iter_advance(). This makes it easier
- * since we can just skip the first segment, which may not
- * be PAGE_SIZE aligned.
- */
- const struct bio_vec *bvec = imu->bvec;
-
- if (offset <= bvec->bv_len) {
- iov_iter_advance(iter, offset);
- } else {
- unsigned long seg_skip;
-
- /* skip first vec */
- offset -= bvec->bv_len;
- seg_skip = 1 + (offset >> PAGE_SHIFT);
-
- iter->bvec = bvec + seg_skip;
- iter->nr_segs -= seg_skip;
- iter->count -= bvec->bv_len + offset;
- iter->iov_offset = offset & ~PAGE_MASK;
- }
- }
-
- return 0;
-}
-
-static int io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter,
- unsigned int issue_flags)
-{
- if (WARN_ON_ONCE(!req->imu))
- return -EFAULT;
- return __io_import_fixed(req, rw, iter, req->imu);
-}
-
-#ifdef CONFIG_COMPAT
-static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
- unsigned int issue_flags)
-{
- struct io_rw *rw = io_kiocb_to_cmd(req);
- struct compat_iovec __user *uiov;
- compat_ssize_t clen;
- void __user *buf;
- size_t len;
-
- uiov = u64_to_user_ptr(rw->addr);
- if (!access_ok(uiov, sizeof(*uiov)))
- return -EFAULT;
- if (__get_user(clen, &uiov->iov_len))
- return -EFAULT;
- if (clen < 0)
- return -EINVAL;
-
- len = clen;
- buf = io_buffer_select(req, &len, issue_flags);
- if (!buf)
- return -ENOBUFS;
- rw->addr = (unsigned long) buf;
- iov[0].iov_base = buf;
- rw->len = iov[0].iov_len = (compat_size_t) len;
- return 0;
-}
-#endif
-
-static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
- unsigned int issue_flags)
-{
- struct io_rw *rw = io_kiocb_to_cmd(req);
- struct iovec __user *uiov = u64_to_user_ptr(rw->addr);
- void __user *buf;
- ssize_t len;
-
- if (copy_from_user(iov, uiov, sizeof(*uiov)))
- return -EFAULT;
-
- len = iov[0].iov_len;
- if (len < 0)
- return -EINVAL;
- buf = io_buffer_select(req, &len, issue_flags);
- if (!buf)
- return -ENOBUFS;
- rw->addr = (unsigned long) buf;
- iov[0].iov_base = buf;
- rw->len = iov[0].iov_len = len;
- return 0;
-}
-
-static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
- unsigned int issue_flags)
-{
- struct io_rw *rw = io_kiocb_to_cmd(req);
-
- if (req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)) {
- iov[0].iov_base = u64_to_user_ptr(rw->addr);
- iov[0].iov_len = rw->len;
- return 0;
- }
- if (rw->len != 1)
- return -EINVAL;
-
-#ifdef CONFIG_COMPAT
- if (req->ctx->compat)
- return io_compat_import(req, iov, issue_flags);
-#endif
-
- return __io_iov_buffer_select(req, iov, issue_flags);
-}
-
-static struct iovec *__io_import_iovec(int ddir, struct io_kiocb *req,
- struct io_rw_state *s,
- unsigned int issue_flags)
-{
- struct io_rw *rw = io_kiocb_to_cmd(req);
- struct iov_iter *iter = &s->iter;
- u8 opcode = req->opcode;
- struct iovec *iovec;
- void __user *buf;
- size_t sqe_len;
- ssize_t ret;
-
- if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
- ret = io_import_fixed(req, ddir, iter, issue_flags);
- if (ret)
- return ERR_PTR(ret);
- return NULL;
- }
-
- buf = u64_to_user_ptr(rw->addr);
- sqe_len = rw->len;
-
- if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
- if (io_do_buffer_select(req)) {
- buf = io_buffer_select(req, &sqe_len, issue_flags);
- if (!buf)
- return ERR_PTR(-ENOBUFS);
- rw->addr = (unsigned long) buf;
- rw->len = sqe_len;
- }
-
- ret = import_single_range(ddir, buf, sqe_len, s->fast_iov, iter);
- if (ret)
- return ERR_PTR(ret);
- return NULL;
- }
-
- iovec = s->fast_iov;
- if (req->flags & REQ_F_BUFFER_SELECT) {
- ret = io_iov_buffer_select(req, iovec, issue_flags);
- if (ret)
- return ERR_PTR(ret);
- iov_iter_init(iter, ddir, iovec, 1, iovec->iov_len);
- return NULL;
- }
-
- ret = __import_iovec(ddir, buf, sqe_len, UIO_FASTIOV, &iovec, iter,
- req->ctx->compat);
- if (unlikely(ret < 0))
- return ERR_PTR(ret);
- return iovec;
-}
-
-static inline int io_import_iovec(int rw, struct io_kiocb *req,
- struct iovec **iovec, struct io_rw_state *s,
- unsigned int issue_flags)
-{
- *iovec = __io_import_iovec(rw, req, s, issue_flags);
- if (unlikely(IS_ERR(*iovec)))
- return PTR_ERR(*iovec);
-
- iov_iter_save_state(&s->iter, &s->iter_state);
- return 0;
-}
-
-static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb)
-{
- return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos;
-}
-
-/*
- * For files that don't have ->read_iter() and ->write_iter(), handle them
- * by looping over ->read() or ->write() manually.
- */
-static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter)
-{
- struct kiocb *kiocb = &rw->kiocb;
- struct file *file = kiocb->ki_filp;
- ssize_t ret = 0;
- loff_t *ppos;
-
- /*
- * Don't support polled IO through this interface, and we can't
- * support non-blocking either. For the latter, this just causes
- * the kiocb to be handled from an async context.
- */
- if (kiocb->ki_flags & IOCB_HIPRI)
- return -EOPNOTSUPP;
- if ((kiocb->ki_flags & IOCB_NOWAIT) &&
- !(kiocb->ki_filp->f_flags & O_NONBLOCK))
- return -EAGAIN;
-
- ppos = io_kiocb_ppos(kiocb);
-
- while (iov_iter_count(iter)) {
- struct iovec iovec;
- ssize_t nr;
-
- if (!iov_iter_is_bvec(iter)) {
- iovec = iov_iter_iovec(iter);
- } else {
- iovec.iov_base = u64_to_user_ptr(rw->addr);
- iovec.iov_len = rw->len;
- }
-
- if (ddir == READ) {
- nr = file->f_op->read(file, iovec.iov_base,
- iovec.iov_len, ppos);
- } else {
- nr = file->f_op->write(file, iovec.iov_base,
- iovec.iov_len, ppos);
- }
-
- if (nr < 0) {
- if (!ret)
- ret = nr;
- break;
- }
- ret += nr;
- if (!iov_iter_is_bvec(iter)) {
- iov_iter_advance(iter, nr);
- } else {
- rw->addr += nr;
- rw->len -= nr;
- if (!rw->len)
- break;
- }
- if (nr != iovec.iov_len)
- break;
- }
-
- return ret;
-}
-
-static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec,
- const struct iovec *fast_iov, struct iov_iter *iter)
-{
- struct io_async_rw *io = req->async_data;
-
- memcpy(&io->s.iter, iter, sizeof(*iter));
- io->free_iovec = iovec;
- io->bytes_done = 0;
- /* can only be fixed buffers, no need to do anything */
- if (iov_iter_is_bvec(iter))
- return;
- if (!iovec) {
- unsigned iov_off = 0;
-
- io->s.iter.iov = io->s.fast_iov;
- if (iter->iov != fast_iov) {
- iov_off = iter->iov - fast_iov;
- io->s.iter.iov += iov_off;
- }
- if (io->s.fast_iov != fast_iov)
- memcpy(io->s.fast_iov + iov_off, fast_iov + iov_off,
- sizeof(struct iovec) * iter->nr_segs);
- } else {
- req->flags |= REQ_F_NEED_CLEANUP;
- }
-}
-
bool io_alloc_async_data(struct io_kiocb *req)
{
WARN_ON_ONCE(!io_op_defs[req->opcode].async_size);
return true;
}
-static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
- struct io_rw_state *s, bool force)
-{
- if (!force && !io_op_defs[req->opcode].prep_async)
- return 0;
- if (!req_has_async_data(req)) {
- struct io_async_rw *iorw;
-
- if (io_alloc_async_data(req)) {
- kfree(iovec);
- return -ENOMEM;
- }
-
- io_req_map_rw(req, iovec, s->fast_iov, &s->iter);
- iorw = req->async_data;
- /* we've copied and mapped the iter, ensure state is saved */
- iov_iter_save_state(&iorw->s.iter, &iorw->s.iter_state);
- }
- return 0;
-}
-
-static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
-{
- struct io_async_rw *iorw = req->async_data;
- struct iovec *iov;
- int ret;
-
- /* submission path, ->uring_lock should already be taken */
- ret = io_import_iovec(rw, req, &iov, &iorw->s, 0);
- if (unlikely(ret < 0))
- return ret;
-
- iorw->bytes_done = 0;
- iorw->free_iovec = iov;
- if (iov)
- req->flags |= REQ_F_NEED_CLEANUP;
- return 0;
-}
-
-static int io_readv_prep_async(struct io_kiocb *req)
-{
- return io_rw_prep_async(req, READ);
-}
-
-static int io_writev_prep_async(struct io_kiocb *req)
-{
- return io_rw_prep_async(req, WRITE);
-}
-
-/*
- * This is our waitqueue callback handler, registered through __folio_lock_async()
- * when we initially tried to do the IO with the iocb armed our waitqueue.
- * This gets called when the page is unlocked, and we generally expect that to
- * happen when the page IO is completed and the page is now uptodate. This will
- * queue a task_work based retry of the operation, attempting to copy the data
- * again. If the latter fails because the page was NOT uptodate, then we will
- * do a thread based blocking retry of the operation. That's the unexpected
- * slow path.
- */
-static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
- int sync, void *arg)
-{
- struct wait_page_queue *wpq;
- struct io_kiocb *req = wait->private;
- struct io_rw *rw = io_kiocb_to_cmd(req);
- struct wait_page_key *key = arg;
-
- wpq = container_of(wait, struct wait_page_queue, wait);
-
- if (!wake_page_match(wpq, key))
- return 0;
-
- rw->kiocb.ki_flags &= ~IOCB_WAITQ;
- list_del_init(&wait->entry);
- io_req_task_queue(req);
- return 1;
-}
-
-/*
- * This controls whether a given IO request should be armed for async page
- * based retry. If we return false here, the request is handed to the async
- * worker threads for retry. If we're doing buffered reads on a regular file,
- * we prepare a private wait_page_queue entry and retry the operation. This
- * will either succeed because the page is now uptodate and unlocked, or it
- * will register a callback when the page is unlocked at IO completion. Through
- * that callback, io_uring uses task_work to setup a retry of the operation.
- * That retry will attempt the buffered read again. The retry will generally
- * succeed, or in rare cases where it fails, we then fall back to using the
- * async worker threads for a blocking retry.
- */
-static bool io_rw_should_retry(struct io_kiocb *req)
-{
- struct io_async_rw *io = req->async_data;
- struct wait_page_queue *wait = &io->wpq;
- struct io_rw *rw = io_kiocb_to_cmd(req);
- struct kiocb *kiocb = &rw->kiocb;
-
- /* never retry for NOWAIT, we just complete with -EAGAIN */
- if (req->flags & REQ_F_NOWAIT)
- return false;
-
- /* Only for buffered IO */
- if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI))
- return false;
-
- /*
- * just use poll if we can, and don't attempt if the fs doesn't
- * support callback based unlocks
- */
- if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC))
- return false;
-
- wait->wait.func = io_async_buf_func;
- wait->wait.private = req;
- wait->wait.flags = 0;
- INIT_LIST_HEAD(&wait->wait.entry);
- kiocb->ki_flags |= IOCB_WAITQ;
- kiocb->ki_flags &= ~IOCB_NOWAIT;
- kiocb->ki_waitq = wait;
- return true;
-}
-
-static inline int io_iter_do_read(struct io_rw *rw, struct iov_iter *iter)
-{
- struct file *file = rw->kiocb.ki_filp;
-
- if (likely(file->f_op->read_iter))
- return call_read_iter(file, &rw->kiocb, iter);
- else if (file->f_op->read)
- return loop_rw_iter(READ, rw, iter);
- else
- return -EINVAL;
-}
-
-static bool need_read_all(struct io_kiocb *req)
-{
- return req->flags & REQ_F_ISREG ||
- S_ISBLK(file_inode(req->file)->i_mode);
-}
-
-static int io_rw_init_file(struct io_kiocb *req, fmode_t mode)
-{
- struct io_rw *rw = io_kiocb_to_cmd(req);
- struct kiocb *kiocb = &rw->kiocb;
- struct io_ring_ctx *ctx = req->ctx;
- struct file *file = req->file;
- int ret;
-
- if (unlikely(!file || !(file->f_mode & mode)))
- return -EBADF;
-
- if (!io_req_ffs_set(req))
- req->flags |= io_file_get_flags(file) << REQ_F_SUPPORT_NOWAIT_BIT;
-
- kiocb->ki_flags = iocb_flags(file);
- ret = kiocb_set_rw_flags(kiocb, rw->flags);
- if (unlikely(ret))
- return ret;
-
- /*
- * If the file is marked O_NONBLOCK, still allow retry for it if it
- * supports async. Otherwise it's impossible to use O_NONBLOCK files
- * reliably. If not, or it IOCB_NOWAIT is set, don't retry.
- */
- if ((kiocb->ki_flags & IOCB_NOWAIT) ||
- ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req)))
- req->flags |= REQ_F_NOWAIT;
-
- if (ctx->flags & IORING_SETUP_IOPOLL) {
- if (!(kiocb->ki_flags & IOCB_DIRECT) || !file->f_op->iopoll)
- return -EOPNOTSUPP;
-
- kiocb->private = NULL;
- kiocb->ki_flags |= IOCB_HIPRI | IOCB_ALLOC_CACHE;
- kiocb->ki_complete = io_complete_rw_iopoll;
- req->iopoll_completed = 0;
- } else {
- if (kiocb->ki_flags & IOCB_HIPRI)
- return -EINVAL;
- kiocb->ki_complete = io_complete_rw;
- }
-
- return 0;
-}
-
-static int io_read(struct io_kiocb *req, unsigned int issue_flags)
-{
- struct io_rw *rw = io_kiocb_to_cmd(req);
- struct io_rw_state __s, *s = &__s;
- struct iovec *iovec;
- struct kiocb *kiocb = &rw->kiocb;
- bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
- struct io_async_rw *io;
- ssize_t ret, ret2;
- loff_t *ppos;
-
- if (!req_has_async_data(req)) {
- ret = io_import_iovec(READ, req, &iovec, s, issue_flags);
- if (unlikely(ret < 0))
- return ret;
- } else {
- io = req->async_data;
- s = &io->s;
-
- /*
- * Safe and required to re-import if we're using provided
- * buffers, as we dropped the selected one before retry.
- */
- if (io_do_buffer_select(req)) {
- ret = io_import_iovec(READ, req, &iovec, s, issue_flags);
- if (unlikely(ret < 0))
- return ret;
- }
-
- /*
- * We come here from an earlier attempt, restore our state to
- * match in case it doesn't. It's cheap enough that we don't
- * need to make this conditional.
- */
- iov_iter_restore(&s->iter, &s->iter_state);
- iovec = NULL;
- }
- ret = io_rw_init_file(req, FMODE_READ);
- if (unlikely(ret)) {
- kfree(iovec);
- return ret;
- }
- req->cqe.res = iov_iter_count(&s->iter);
-
- if (force_nonblock) {
- /* If the file doesn't support async, just async punt */
- if (unlikely(!io_file_supports_nowait(req))) {
- ret = io_setup_async_rw(req, iovec, s, true);
- return ret ?: -EAGAIN;
- }
- kiocb->ki_flags |= IOCB_NOWAIT;
- } else {
- /* Ensure we clear previously set non-block flag */
- kiocb->ki_flags &= ~IOCB_NOWAIT;
- }
-
- ppos = io_kiocb_update_pos(req);
-
- ret = rw_verify_area(READ, req->file, ppos, req->cqe.res);
- if (unlikely(ret)) {
- kfree(iovec);
- return ret;
- }
-
- ret = io_iter_do_read(rw, &s->iter);
-
- if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) {
- req->flags &= ~REQ_F_REISSUE;
- /* if we can poll, just do that */
- if (req->opcode == IORING_OP_READ && file_can_poll(req->file))
- return -EAGAIN;
- /* IOPOLL retry should happen for io-wq threads */
- if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))
- goto done;
- /* no retry on NONBLOCK nor RWF_NOWAIT */
- if (req->flags & REQ_F_NOWAIT)
- goto done;
- ret = 0;
- } else if (ret == -EIOCBQUEUED) {
- goto out_free;
- } else if (ret == req->cqe.res || ret <= 0 || !force_nonblock ||
- (req->flags & REQ_F_NOWAIT) || !need_read_all(req)) {
- /* read all, failed, already did sync or don't want to retry */
- goto done;
- }
-
- /*
- * Don't depend on the iter state matching what was consumed, or being
- * untouched in case of error. Restore it and we'll advance it
- * manually if we need to.
- */
- iov_iter_restore(&s->iter, &s->iter_state);
-
- ret2 = io_setup_async_rw(req, iovec, s, true);
- if (ret2)
- return ret2;
-
- iovec = NULL;
- io = req->async_data;
- s = &io->s;
- /*
- * Now use our persistent iterator and state, if we aren't already.
- * We've restored and mapped the iter to match.
- */
-
- do {
- /*
- * We end up here because of a partial read, either from
- * above or inside this loop. Advance the iter by the bytes
- * that were consumed.
- */
- iov_iter_advance(&s->iter, ret);
- if (!iov_iter_count(&s->iter))
- break;
- io->bytes_done += ret;
- iov_iter_save_state(&s->iter, &s->iter_state);
-
- /* if we can retry, do so with the callbacks armed */
- if (!io_rw_should_retry(req)) {
- kiocb->ki_flags &= ~IOCB_WAITQ;
- return -EAGAIN;
- }
-
- /*
- * Now retry read with the IOCB_WAITQ parts set in the iocb. If
- * we get -EIOCBQUEUED, then we'll get a notification when the
- * desired page gets unlocked. We can also get a partial read
- * here, and if we do, then just retry at the new offset.
- */
- ret = io_iter_do_read(rw, &s->iter);
- if (ret == -EIOCBQUEUED)
- return IOU_ISSUE_SKIP_COMPLETE;
- /* we got some bytes, but not all. retry. */
- kiocb->ki_flags &= ~IOCB_WAITQ;
- iov_iter_restore(&s->iter, &s->iter_state);
- } while (ret > 0);
-done:
- kiocb_done(req, ret, issue_flags);
-out_free:
- /* it's faster to check here then delegate to kfree */
- if (iovec)
- kfree(iovec);
- return IOU_ISSUE_SKIP_COMPLETE;
-}
-
-static int io_write(struct io_kiocb *req, unsigned int issue_flags)
-{
- struct io_rw *rw = io_kiocb_to_cmd(req);
- struct io_rw_state __s, *s = &__s;
- struct iovec *iovec;
- struct kiocb *kiocb = &rw->kiocb;
- bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
- ssize_t ret, ret2;
- loff_t *ppos;
-
- if (!req_has_async_data(req)) {
- ret = io_import_iovec(WRITE, req, &iovec, s, issue_flags);
- if (unlikely(ret < 0))
- return ret;
- } else {
- struct io_async_rw *io = req->async_data;
-
- s = &io->s;
- iov_iter_restore(&s->iter, &s->iter_state);
- iovec = NULL;
- }
- ret = io_rw_init_file(req, FMODE_WRITE);
- if (unlikely(ret)) {
- kfree(iovec);
- return ret;
- }
- req->cqe.res = iov_iter_count(&s->iter);
-
- if (force_nonblock) {
- /* If the file doesn't support async, just async punt */
- if (unlikely(!io_file_supports_nowait(req)))
- goto copy_iov;
-
- /* file path doesn't support NOWAIT for non-direct_IO */
- if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
- (req->flags & REQ_F_ISREG))
- goto copy_iov;
-
- kiocb->ki_flags |= IOCB_NOWAIT;
- } else {
- /* Ensure we clear previously set non-block flag */
- kiocb->ki_flags &= ~IOCB_NOWAIT;
- }
-
- ppos = io_kiocb_update_pos(req);
-
- ret = rw_verify_area(WRITE, req->file, ppos, req->cqe.res);
- if (unlikely(ret))
- goto out_free;
-
- /*
- * Open-code file_start_write here to grab freeze protection,
- * which will be released by another thread in
- * io_complete_rw(). Fool lockdep by telling it the lock got
- * released so that it doesn't complain about the held lock when
- * we return to userspace.
- */
- if (req->flags & REQ_F_ISREG) {
- sb_start_write(file_inode(req->file)->i_sb);
- __sb_writers_release(file_inode(req->file)->i_sb,
- SB_FREEZE_WRITE);
- }
- kiocb->ki_flags |= IOCB_WRITE;
-
- if (likely(req->file->f_op->write_iter))
- ret2 = call_write_iter(req->file, kiocb, &s->iter);
- else if (req->file->f_op->write)
- ret2 = loop_rw_iter(WRITE, rw, &s->iter);
- else
- ret2 = -EINVAL;
-
- if (req->flags & REQ_F_REISSUE) {
- req->flags &= ~REQ_F_REISSUE;
- ret2 = -EAGAIN;
- }
-
- /*
- * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just
- * retry them without IOCB_NOWAIT.
- */
- if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
- ret2 = -EAGAIN;
- /* no retry on NONBLOCK nor RWF_NOWAIT */
- if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT))
- goto done;
- if (!force_nonblock || ret2 != -EAGAIN) {
- /* IOPOLL retry should happen for io-wq threads */
- if (ret2 == -EAGAIN && (req->ctx->flags & IORING_SETUP_IOPOLL))
- goto copy_iov;
-done:
- kiocb_done(req, ret2, issue_flags);
- ret = IOU_ISSUE_SKIP_COMPLETE;
- } else {
-copy_iov:
- iov_iter_restore(&s->iter, &s->iter_state);
- ret = io_setup_async_rw(req, iovec, s, false);
- return ret ?: -EAGAIN;
- }
-out_free:
- /* it's reportedly faster than delegating the null check to kfree() */
- if (iovec)
- kfree(iovec);
- return ret;
-}
-
static __maybe_unused int io_eopnotsupp_prep(struct io_kiocb *kiocb,
const struct io_uring_sqe *sqe)
{
return -EOPNOTSUPP;
}
-static int io_req_prep_async(struct io_kiocb *req)
+int io_req_prep_async(struct io_kiocb *req)
{
const struct io_op_def *def = &io_op_defs[req->opcode];
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/blk-mq.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/fsnotify.h>
+#include <linux/poll.h>
+#include <linux/nospec.h>
+#include <linux/compat.h>
+#include <linux/io_uring.h>
+
+#include <uapi/linux/io_uring.h>
+
+#include "io_uring_types.h"
+#include "io_uring.h"
+#include "opdef.h"
+#include "kbuf.h"
+#include "rsrc.h"
+#include "rw.h"
+
+struct io_rw {
+ /* NOTE: kiocb has the file as the first member, so don't do it here */
+ struct kiocb kiocb;
+ u64 addr;
+ u32 len;
+ rwf_t flags;
+};
+
+static inline bool io_file_supports_nowait(struct io_kiocb *req)
+{
+ return req->flags & REQ_F_SUPPORT_NOWAIT;
+}
+
+int io_prep_rw(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+ unsigned ioprio;
+ int ret;
+
+ rw->kiocb.ki_pos = READ_ONCE(sqe->off);
+ /* used for fixed read/write too - just read unconditionally */
+ req->buf_index = READ_ONCE(sqe->buf_index);
+
+ if (req->opcode == IORING_OP_READ_FIXED ||
+ req->opcode == IORING_OP_WRITE_FIXED) {
+ struct io_ring_ctx *ctx = req->ctx;
+ u16 index;
+
+ if (unlikely(req->buf_index >= ctx->nr_user_bufs))
+ return -EFAULT;
+ index = array_index_nospec(req->buf_index, ctx->nr_user_bufs);
+ req->imu = ctx->user_bufs[index];
+ io_req_set_rsrc_node(req, ctx, 0);
+ }
+
+ ioprio = READ_ONCE(sqe->ioprio);
+ if (ioprio) {
+ ret = ioprio_check_cap(ioprio);
+ if (ret)
+ return ret;
+
+ rw->kiocb.ki_ioprio = ioprio;
+ } else {
+ rw->kiocb.ki_ioprio = get_current_ioprio();
+ }
+
+ rw->addr = READ_ONCE(sqe->addr);
+ rw->len = READ_ONCE(sqe->len);
+ rw->flags = READ_ONCE(sqe->rw_flags);
+ return 0;
+}
+
+void io_readv_writev_cleanup(struct io_kiocb *req)
+{
+ struct io_async_rw *io = req->async_data;
+
+ kfree(io->free_iovec);
+}
+
+static inline void io_rw_done(struct kiocb *kiocb, ssize_t ret)
+{
+ switch (ret) {
+ case -EIOCBQUEUED:
+ break;
+ case -ERESTARTSYS:
+ case -ERESTARTNOINTR:
+ case -ERESTARTNOHAND:
+ case -ERESTART_RESTARTBLOCK:
+ /*
+ * We can't just restart the syscall, since previously
+ * submitted sqes may already be in progress. Just fail this
+ * IO with EINTR.
+ */
+ ret = -EINTR;
+ fallthrough;
+ default:
+ kiocb->ki_complete(kiocb, ret);
+ }
+}
+
+static inline loff_t *io_kiocb_update_pos(struct io_kiocb *req)
+{
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+
+ if (rw->kiocb.ki_pos != -1)
+ return &rw->kiocb.ki_pos;
+
+ if (!(req->file->f_mode & FMODE_STREAM)) {
+ req->flags |= REQ_F_CUR_POS;
+ rw->kiocb.ki_pos = req->file->f_pos;
+ return &rw->kiocb.ki_pos;
+ }
+
+ rw->kiocb.ki_pos = 0;
+ return NULL;
+}
+
+static void io_req_task_queue_reissue(struct io_kiocb *req)
+{
+ req->io_task_work.func = io_queue_iowq;
+ io_req_task_work_add(req);
+}
+
+#ifdef CONFIG_BLOCK
+static bool io_resubmit_prep(struct io_kiocb *req)
+{
+ struct io_async_rw *io = req->async_data;
+
+ if (!req_has_async_data(req))
+ return !io_req_prep_async(req);
+ iov_iter_restore(&io->s.iter, &io->s.iter_state);
+ return true;
+}
+
+static bool io_rw_should_reissue(struct io_kiocb *req)
+{
+ umode_t mode = file_inode(req->file)->i_mode;
+ struct io_ring_ctx *ctx = req->ctx;
+
+ if (!S_ISBLK(mode) && !S_ISREG(mode))
+ return false;
+ if ((req->flags & REQ_F_NOWAIT) || (io_wq_current_is_worker() &&
+ !(ctx->flags & IORING_SETUP_IOPOLL)))
+ return false;
+ /*
+ * If ref is dying, we might be running poll reap from the exit work.
+ * Don't attempt to reissue from that path, just let it fail with
+ * -EAGAIN.
+ */
+ if (percpu_ref_is_dying(&ctx->refs))
+ return false;
+ /*
+ * Play it safe and assume not safe to re-import and reissue if we're
+ * not in the original thread group (or in task context).
+ */
+ if (!same_thread_group(req->task, current) || !in_task())
+ return false;
+ return true;
+}
+#else
+static bool io_resubmit_prep(struct io_kiocb *req)
+{
+ return false;
+}
+static bool io_rw_should_reissue(struct io_kiocb *req)
+{
+ return false;
+}
+#endif
+
+static void kiocb_end_write(struct io_kiocb *req)
+{
+ /*
+ * Tell lockdep we inherited freeze protection from submission
+ * thread.
+ */
+ if (req->flags & REQ_F_ISREG) {
+ struct super_block *sb = file_inode(req->file)->i_sb;
+
+ __sb_writers_acquired(sb, SB_FREEZE_WRITE);
+ sb_end_write(sb);
+ }
+}
+
+static bool __io_complete_rw_common(struct io_kiocb *req, long res)
+{
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+
+ if (rw->kiocb.ki_flags & IOCB_WRITE) {
+ kiocb_end_write(req);
+ fsnotify_modify(req->file);
+ } else {
+ fsnotify_access(req->file);
+ }
+ if (unlikely(res != req->cqe.res)) {
+ if ((res == -EAGAIN || res == -EOPNOTSUPP) &&
+ io_rw_should_reissue(req)) {
+ req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO;
+ return true;
+ }
+ req_set_fail(req);
+ req->cqe.res = res;
+ }
+ return false;
+}
+
+static void __io_complete_rw(struct io_kiocb *req, long res,
+ unsigned int issue_flags)
+{
+ if (__io_complete_rw_common(req, res))
+ return;
+ io_req_set_res(req, req->cqe.res, io_put_kbuf(req, issue_flags));
+ __io_req_complete(req, issue_flags);
+}
+
+static void io_complete_rw(struct kiocb *kiocb, long res)
+{
+ struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb);
+ struct io_kiocb *req = cmd_to_io_kiocb(rw);
+
+ if (__io_complete_rw_common(req, res))
+ return;
+ io_req_set_res(req, res, 0);
+ req->io_task_work.func = io_req_task_complete;
+ io_req_task_prio_work_add(req);
+}
+
+static void io_complete_rw_iopoll(struct kiocb *kiocb, long res)
+{
+ struct io_rw *rw = container_of(kiocb, struct io_rw, kiocb);
+ struct io_kiocb *req = cmd_to_io_kiocb(rw);
+
+ if (kiocb->ki_flags & IOCB_WRITE)
+ kiocb_end_write(req);
+ if (unlikely(res != req->cqe.res)) {
+ if (res == -EAGAIN && io_rw_should_reissue(req)) {
+ req->flags |= REQ_F_REISSUE | REQ_F_PARTIAL_IO;
+ return;
+ }
+ req->cqe.res = res;
+ }
+
+ /* order with io_iopoll_complete() checking ->iopoll_completed */
+ smp_store_release(&req->iopoll_completed, 1);
+}
+
+static void kiocb_done(struct io_kiocb *req, ssize_t ret,
+ unsigned int issue_flags)
+{
+ struct io_async_rw *io = req->async_data;
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+
+ /* add previously done IO, if any */
+ if (req_has_async_data(req) && io->bytes_done > 0) {
+ if (ret < 0)
+ ret = io->bytes_done;
+ else
+ ret += io->bytes_done;
+ }
+
+ if (req->flags & REQ_F_CUR_POS)
+ req->file->f_pos = rw->kiocb.ki_pos;
+ if (ret >= 0 && (rw->kiocb.ki_complete == io_complete_rw))
+ __io_complete_rw(req, ret, issue_flags);
+ else
+ io_rw_done(&rw->kiocb, ret);
+
+ if (req->flags & REQ_F_REISSUE) {
+ req->flags &= ~REQ_F_REISSUE;
+ if (io_resubmit_prep(req))
+ io_req_task_queue_reissue(req);
+ else
+ io_req_task_queue_fail(req, ret);
+ }
+}
+
+static int __io_import_fixed(struct io_kiocb *req, int ddir,
+ struct iov_iter *iter, struct io_mapped_ubuf *imu)
+{
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+ size_t len = rw->len;
+ u64 buf_end, buf_addr = rw->addr;
+ size_t offset;
+
+ if (unlikely(check_add_overflow(buf_addr, (u64)len, &buf_end)))
+ return -EFAULT;
+ /* not inside the mapped region */
+ if (unlikely(buf_addr < imu->ubuf || buf_end > imu->ubuf_end))
+ return -EFAULT;
+
+ /*
+ * May not be a start of buffer, set size appropriately
+ * and advance us to the beginning.
+ */
+ offset = buf_addr - imu->ubuf;
+ iov_iter_bvec(iter, ddir, imu->bvec, imu->nr_bvecs, offset + len);
+
+ if (offset) {
+ /*
+ * Don't use iov_iter_advance() here, as it's really slow for
+ * using the latter parts of a big fixed buffer - it iterates
+ * over each segment manually. We can cheat a bit here, because
+ * we know that:
+ *
+ * 1) it's a BVEC iter, we set it up
+ * 2) all bvecs are PAGE_SIZE in size, except potentially the
+ * first and last bvec
+ *
+ * So just find our index, and adjust the iterator afterwards.
+ * If the offset is within the first bvec (or the whole first
+ * bvec, just use iov_iter_advance(). This makes it easier
+ * since we can just skip the first segment, which may not
+ * be PAGE_SIZE aligned.
+ */
+ const struct bio_vec *bvec = imu->bvec;
+
+ if (offset <= bvec->bv_len) {
+ iov_iter_advance(iter, offset);
+ } else {
+ unsigned long seg_skip;
+
+ /* skip first vec */
+ offset -= bvec->bv_len;
+ seg_skip = 1 + (offset >> PAGE_SHIFT);
+
+ iter->bvec = bvec + seg_skip;
+ iter->nr_segs -= seg_skip;
+ iter->count -= bvec->bv_len + offset;
+ iter->iov_offset = offset & ~PAGE_MASK;
+ }
+ }
+
+ return 0;
+}
+
+static int io_import_fixed(struct io_kiocb *req, int rw, struct iov_iter *iter,
+ unsigned int issue_flags)
+{
+ if (WARN_ON_ONCE(!req->imu))
+ return -EFAULT;
+ return __io_import_fixed(req, rw, iter, req->imu);
+}
+
+#ifdef CONFIG_COMPAT
+static ssize_t io_compat_import(struct io_kiocb *req, struct iovec *iov,
+ unsigned int issue_flags)
+{
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+ struct compat_iovec __user *uiov;
+ compat_ssize_t clen;
+ void __user *buf;
+ size_t len;
+
+ uiov = u64_to_user_ptr(rw->addr);
+ if (!access_ok(uiov, sizeof(*uiov)))
+ return -EFAULT;
+ if (__get_user(clen, &uiov->iov_len))
+ return -EFAULT;
+ if (clen < 0)
+ return -EINVAL;
+
+ len = clen;
+ buf = io_buffer_select(req, &len, issue_flags);
+ if (!buf)
+ return -ENOBUFS;
+ rw->addr = (unsigned long) buf;
+ iov[0].iov_base = buf;
+ rw->len = iov[0].iov_len = (compat_size_t) len;
+ return 0;
+}
+#endif
+
+static ssize_t __io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
+ unsigned int issue_flags)
+{
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+ struct iovec __user *uiov = u64_to_user_ptr(rw->addr);
+ void __user *buf;
+ ssize_t len;
+
+ if (copy_from_user(iov, uiov, sizeof(*uiov)))
+ return -EFAULT;
+
+ len = iov[0].iov_len;
+ if (len < 0)
+ return -EINVAL;
+ buf = io_buffer_select(req, &len, issue_flags);
+ if (!buf)
+ return -ENOBUFS;
+ rw->addr = (unsigned long) buf;
+ iov[0].iov_base = buf;
+ rw->len = iov[0].iov_len = len;
+ return 0;
+}
+
+static ssize_t io_iov_buffer_select(struct io_kiocb *req, struct iovec *iov,
+ unsigned int issue_flags)
+{
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+
+ if (req->flags & (REQ_F_BUFFER_SELECTED|REQ_F_BUFFER_RING)) {
+ iov[0].iov_base = u64_to_user_ptr(rw->addr);
+ iov[0].iov_len = rw->len;
+ return 0;
+ }
+ if (rw->len != 1)
+ return -EINVAL;
+
+#ifdef CONFIG_COMPAT
+ if (req->ctx->compat)
+ return io_compat_import(req, iov, issue_flags);
+#endif
+
+ return __io_iov_buffer_select(req, iov, issue_flags);
+}
+
+static struct iovec *__io_import_iovec(int ddir, struct io_kiocb *req,
+ struct io_rw_state *s,
+ unsigned int issue_flags)
+{
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+ struct iov_iter *iter = &s->iter;
+ u8 opcode = req->opcode;
+ struct iovec *iovec;
+ void __user *buf;
+ size_t sqe_len;
+ ssize_t ret;
+
+ if (opcode == IORING_OP_READ_FIXED || opcode == IORING_OP_WRITE_FIXED) {
+ ret = io_import_fixed(req, ddir, iter, issue_flags);
+ if (ret)
+ return ERR_PTR(ret);
+ return NULL;
+ }
+
+ buf = u64_to_user_ptr(rw->addr);
+ sqe_len = rw->len;
+
+ if (opcode == IORING_OP_READ || opcode == IORING_OP_WRITE) {
+ if (io_do_buffer_select(req)) {
+ buf = io_buffer_select(req, &sqe_len, issue_flags);
+ if (!buf)
+ return ERR_PTR(-ENOBUFS);
+ rw->addr = (unsigned long) buf;
+ rw->len = sqe_len;
+ }
+
+ ret = import_single_range(ddir, buf, sqe_len, s->fast_iov, iter);
+ if (ret)
+ return ERR_PTR(ret);
+ return NULL;
+ }
+
+ iovec = s->fast_iov;
+ if (req->flags & REQ_F_BUFFER_SELECT) {
+ ret = io_iov_buffer_select(req, iovec, issue_flags);
+ if (ret)
+ return ERR_PTR(ret);
+ iov_iter_init(iter, ddir, iovec, 1, iovec->iov_len);
+ return NULL;
+ }
+
+ ret = __import_iovec(ddir, buf, sqe_len, UIO_FASTIOV, &iovec, iter,
+ req->ctx->compat);
+ if (unlikely(ret < 0))
+ return ERR_PTR(ret);
+ return iovec;
+}
+
+static inline int io_import_iovec(int rw, struct io_kiocb *req,
+ struct iovec **iovec, struct io_rw_state *s,
+ unsigned int issue_flags)
+{
+ *iovec = __io_import_iovec(rw, req, s, issue_flags);
+ if (unlikely(IS_ERR(*iovec)))
+ return PTR_ERR(*iovec);
+
+ iov_iter_save_state(&s->iter, &s->iter_state);
+ return 0;
+}
+
+static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb)
+{
+ return (kiocb->ki_filp->f_mode & FMODE_STREAM) ? NULL : &kiocb->ki_pos;
+}
+
+/*
+ * For files that don't have ->read_iter() and ->write_iter(), handle them
+ * by looping over ->read() or ->write() manually.
+ */
+static ssize_t loop_rw_iter(int ddir, struct io_rw *rw, struct iov_iter *iter)
+{
+ struct kiocb *kiocb = &rw->kiocb;
+ struct file *file = kiocb->ki_filp;
+ ssize_t ret = 0;
+ loff_t *ppos;
+
+ /*
+ * Don't support polled IO through this interface, and we can't
+ * support non-blocking either. For the latter, this just causes
+ * the kiocb to be handled from an async context.
+ */
+ if (kiocb->ki_flags & IOCB_HIPRI)
+ return -EOPNOTSUPP;
+ if ((kiocb->ki_flags & IOCB_NOWAIT) &&
+ !(kiocb->ki_filp->f_flags & O_NONBLOCK))
+ return -EAGAIN;
+
+ ppos = io_kiocb_ppos(kiocb);
+
+ while (iov_iter_count(iter)) {
+ struct iovec iovec;
+ ssize_t nr;
+
+ if (!iov_iter_is_bvec(iter)) {
+ iovec = iov_iter_iovec(iter);
+ } else {
+ iovec.iov_base = u64_to_user_ptr(rw->addr);
+ iovec.iov_len = rw->len;
+ }
+
+ if (ddir == READ) {
+ nr = file->f_op->read(file, iovec.iov_base,
+ iovec.iov_len, ppos);
+ } else {
+ nr = file->f_op->write(file, iovec.iov_base,
+ iovec.iov_len, ppos);
+ }
+
+ if (nr < 0) {
+ if (!ret)
+ ret = nr;
+ break;
+ }
+ ret += nr;
+ if (!iov_iter_is_bvec(iter)) {
+ iov_iter_advance(iter, nr);
+ } else {
+ rw->addr += nr;
+ rw->len -= nr;
+ if (!rw->len)
+ break;
+ }
+ if (nr != iovec.iov_len)
+ break;
+ }
+
+ return ret;
+}
+
+static void io_req_map_rw(struct io_kiocb *req, const struct iovec *iovec,
+ const struct iovec *fast_iov, struct iov_iter *iter)
+{
+ struct io_async_rw *io = req->async_data;
+
+ memcpy(&io->s.iter, iter, sizeof(*iter));
+ io->free_iovec = iovec;
+ io->bytes_done = 0;
+ /* can only be fixed buffers, no need to do anything */
+ if (iov_iter_is_bvec(iter))
+ return;
+ if (!iovec) {
+ unsigned iov_off = 0;
+
+ io->s.iter.iov = io->s.fast_iov;
+ if (iter->iov != fast_iov) {
+ iov_off = iter->iov - fast_iov;
+ io->s.iter.iov += iov_off;
+ }
+ if (io->s.fast_iov != fast_iov)
+ memcpy(io->s.fast_iov + iov_off, fast_iov + iov_off,
+ sizeof(struct iovec) * iter->nr_segs);
+ } else {
+ req->flags |= REQ_F_NEED_CLEANUP;
+ }
+}
+
+static int io_setup_async_rw(struct io_kiocb *req, const struct iovec *iovec,
+ struct io_rw_state *s, bool force)
+{
+ if (!force && !io_op_defs[req->opcode].prep_async)
+ return 0;
+ if (!req_has_async_data(req)) {
+ struct io_async_rw *iorw;
+
+ if (io_alloc_async_data(req)) {
+ kfree(iovec);
+ return -ENOMEM;
+ }
+
+ io_req_map_rw(req, iovec, s->fast_iov, &s->iter);
+ iorw = req->async_data;
+ /* we've copied and mapped the iter, ensure state is saved */
+ iov_iter_save_state(&iorw->s.iter, &iorw->s.iter_state);
+ }
+ return 0;
+}
+
+static inline int io_rw_prep_async(struct io_kiocb *req, int rw)
+{
+ struct io_async_rw *iorw = req->async_data;
+ struct iovec *iov;
+ int ret;
+
+ /* submission path, ->uring_lock should already be taken */
+ ret = io_import_iovec(rw, req, &iov, &iorw->s, 0);
+ if (unlikely(ret < 0))
+ return ret;
+
+ iorw->bytes_done = 0;
+ iorw->free_iovec = iov;
+ if (iov)
+ req->flags |= REQ_F_NEED_CLEANUP;
+ return 0;
+}
+
+int io_readv_prep_async(struct io_kiocb *req)
+{
+ return io_rw_prep_async(req, READ);
+}
+
+int io_writev_prep_async(struct io_kiocb *req)
+{
+ return io_rw_prep_async(req, WRITE);
+}
+
+/*
+ * This is our waitqueue callback handler, registered through __folio_lock_async()
+ * when we initially tried to do the IO with the iocb armed our waitqueue.
+ * This gets called when the page is unlocked, and we generally expect that to
+ * happen when the page IO is completed and the page is now uptodate. This will
+ * queue a task_work based retry of the operation, attempting to copy the data
+ * again. If the latter fails because the page was NOT uptodate, then we will
+ * do a thread based blocking retry of the operation. That's the unexpected
+ * slow path.
+ */
+static int io_async_buf_func(struct wait_queue_entry *wait, unsigned mode,
+ int sync, void *arg)
+{
+ struct wait_page_queue *wpq;
+ struct io_kiocb *req = wait->private;
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+ struct wait_page_key *key = arg;
+
+ wpq = container_of(wait, struct wait_page_queue, wait);
+
+ if (!wake_page_match(wpq, key))
+ return 0;
+
+ rw->kiocb.ki_flags &= ~IOCB_WAITQ;
+ list_del_init(&wait->entry);
+ io_req_task_queue(req);
+ return 1;
+}
+
+/*
+ * This controls whether a given IO request should be armed for async page
+ * based retry. If we return false here, the request is handed to the async
+ * worker threads for retry. If we're doing buffered reads on a regular file,
+ * we prepare a private wait_page_queue entry and retry the operation. This
+ * will either succeed because the page is now uptodate and unlocked, or it
+ * will register a callback when the page is unlocked at IO completion. Through
+ * that callback, io_uring uses task_work to setup a retry of the operation.
+ * That retry will attempt the buffered read again. The retry will generally
+ * succeed, or in rare cases where it fails, we then fall back to using the
+ * async worker threads for a blocking retry.
+ */
+static bool io_rw_should_retry(struct io_kiocb *req)
+{
+ struct io_async_rw *io = req->async_data;
+ struct wait_page_queue *wait = &io->wpq;
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+ struct kiocb *kiocb = &rw->kiocb;
+
+ /* never retry for NOWAIT, we just complete with -EAGAIN */
+ if (req->flags & REQ_F_NOWAIT)
+ return false;
+
+ /* Only for buffered IO */
+ if (kiocb->ki_flags & (IOCB_DIRECT | IOCB_HIPRI))
+ return false;
+
+ /*
+ * just use poll if we can, and don't attempt if the fs doesn't
+ * support callback based unlocks
+ */
+ if (file_can_poll(req->file) || !(req->file->f_mode & FMODE_BUF_RASYNC))
+ return false;
+
+ wait->wait.func = io_async_buf_func;
+ wait->wait.private = req;
+ wait->wait.flags = 0;
+ INIT_LIST_HEAD(&wait->wait.entry);
+ kiocb->ki_flags |= IOCB_WAITQ;
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
+ kiocb->ki_waitq = wait;
+ return true;
+}
+
+static inline int io_iter_do_read(struct io_rw *rw, struct iov_iter *iter)
+{
+ struct file *file = rw->kiocb.ki_filp;
+
+ if (likely(file->f_op->read_iter))
+ return call_read_iter(file, &rw->kiocb, iter);
+ else if (file->f_op->read)
+ return loop_rw_iter(READ, rw, iter);
+ else
+ return -EINVAL;
+}
+
+static bool need_read_all(struct io_kiocb *req)
+{
+ return req->flags & REQ_F_ISREG ||
+ S_ISBLK(file_inode(req->file)->i_mode);
+}
+
+static inline bool io_req_ffs_set(struct io_kiocb *req)
+{
+ return req->flags & REQ_F_FIXED_FILE;
+}
+
+static int io_rw_init_file(struct io_kiocb *req, fmode_t mode)
+{
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+ struct kiocb *kiocb = &rw->kiocb;
+ struct io_ring_ctx *ctx = req->ctx;
+ struct file *file = req->file;
+ int ret;
+
+ if (unlikely(!file || !(file->f_mode & mode)))
+ return -EBADF;
+
+ if (!io_req_ffs_set(req))
+ req->flags |= io_file_get_flags(file) << REQ_F_SUPPORT_NOWAIT_BIT;
+
+ kiocb->ki_flags = iocb_flags(file);
+ ret = kiocb_set_rw_flags(kiocb, rw->flags);
+ if (unlikely(ret))
+ return ret;
+
+ /*
+ * If the file is marked O_NONBLOCK, still allow retry for it if it
+ * supports async. Otherwise it's impossible to use O_NONBLOCK files
+ * reliably. If not, or it IOCB_NOWAIT is set, don't retry.
+ */
+ if ((kiocb->ki_flags & IOCB_NOWAIT) ||
+ ((file->f_flags & O_NONBLOCK) && !io_file_supports_nowait(req)))
+ req->flags |= REQ_F_NOWAIT;
+
+ if (ctx->flags & IORING_SETUP_IOPOLL) {
+ if (!(kiocb->ki_flags & IOCB_DIRECT) || !file->f_op->iopoll)
+ return -EOPNOTSUPP;
+
+ kiocb->private = NULL;
+ kiocb->ki_flags |= IOCB_HIPRI | IOCB_ALLOC_CACHE;
+ kiocb->ki_complete = io_complete_rw_iopoll;
+ req->iopoll_completed = 0;
+ } else {
+ if (kiocb->ki_flags & IOCB_HIPRI)
+ return -EINVAL;
+ kiocb->ki_complete = io_complete_rw;
+ }
+
+ return 0;
+}
+
+int io_read(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+ struct io_rw_state __s, *s = &__s;
+ struct iovec *iovec;
+ struct kiocb *kiocb = &rw->kiocb;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+ struct io_async_rw *io;
+ ssize_t ret, ret2;
+ loff_t *ppos;
+
+ if (!req_has_async_data(req)) {
+ ret = io_import_iovec(READ, req, &iovec, s, issue_flags);
+ if (unlikely(ret < 0))
+ return ret;
+ } else {
+ io = req->async_data;
+ s = &io->s;
+
+ /*
+ * Safe and required to re-import if we're using provided
+ * buffers, as we dropped the selected one before retry.
+ */
+ if (io_do_buffer_select(req)) {
+ ret = io_import_iovec(READ, req, &iovec, s, issue_flags);
+ if (unlikely(ret < 0))
+ return ret;
+ }
+
+ /*
+ * We come here from an earlier attempt, restore our state to
+ * match in case it doesn't. It's cheap enough that we don't
+ * need to make this conditional.
+ */
+ iov_iter_restore(&s->iter, &s->iter_state);
+ iovec = NULL;
+ }
+ ret = io_rw_init_file(req, FMODE_READ);
+ if (unlikely(ret)) {
+ kfree(iovec);
+ return ret;
+ }
+ req->cqe.res = iov_iter_count(&s->iter);
+
+ if (force_nonblock) {
+ /* If the file doesn't support async, just async punt */
+ if (unlikely(!io_file_supports_nowait(req))) {
+ ret = io_setup_async_rw(req, iovec, s, true);
+ return ret ?: -EAGAIN;
+ }
+ kiocb->ki_flags |= IOCB_NOWAIT;
+ } else {
+ /* Ensure we clear previously set non-block flag */
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
+ }
+
+ ppos = io_kiocb_update_pos(req);
+
+ ret = rw_verify_area(READ, req->file, ppos, req->cqe.res);
+ if (unlikely(ret)) {
+ kfree(iovec);
+ return ret;
+ }
+
+ ret = io_iter_do_read(rw, &s->iter);
+
+ if (ret == -EAGAIN || (req->flags & REQ_F_REISSUE)) {
+ req->flags &= ~REQ_F_REISSUE;
+ /* if we can poll, just do that */
+ if (req->opcode == IORING_OP_READ && file_can_poll(req->file))
+ return -EAGAIN;
+ /* IOPOLL retry should happen for io-wq threads */
+ if (!force_nonblock && !(req->ctx->flags & IORING_SETUP_IOPOLL))
+ goto done;
+ /* no retry on NONBLOCK nor RWF_NOWAIT */
+ if (req->flags & REQ_F_NOWAIT)
+ goto done;
+ ret = 0;
+ } else if (ret == -EIOCBQUEUED) {
+ goto out_free;
+ } else if (ret == req->cqe.res || ret <= 0 || !force_nonblock ||
+ (req->flags & REQ_F_NOWAIT) || !need_read_all(req)) {
+ /* read all, failed, already did sync or don't want to retry */
+ goto done;
+ }
+
+ /*
+ * Don't depend on the iter state matching what was consumed, or being
+ * untouched in case of error. Restore it and we'll advance it
+ * manually if we need to.
+ */
+ iov_iter_restore(&s->iter, &s->iter_state);
+
+ ret2 = io_setup_async_rw(req, iovec, s, true);
+ if (ret2)
+ return ret2;
+
+ iovec = NULL;
+ io = req->async_data;
+ s = &io->s;
+ /*
+ * Now use our persistent iterator and state, if we aren't already.
+ * We've restored and mapped the iter to match.
+ */
+
+ do {
+ /*
+ * We end up here because of a partial read, either from
+ * above or inside this loop. Advance the iter by the bytes
+ * that were consumed.
+ */
+ iov_iter_advance(&s->iter, ret);
+ if (!iov_iter_count(&s->iter))
+ break;
+ io->bytes_done += ret;
+ iov_iter_save_state(&s->iter, &s->iter_state);
+
+ /* if we can retry, do so with the callbacks armed */
+ if (!io_rw_should_retry(req)) {
+ kiocb->ki_flags &= ~IOCB_WAITQ;
+ return -EAGAIN;
+ }
+
+ /*
+ * Now retry read with the IOCB_WAITQ parts set in the iocb. If
+ * we get -EIOCBQUEUED, then we'll get a notification when the
+ * desired page gets unlocked. We can also get a partial read
+ * here, and if we do, then just retry at the new offset.
+ */
+ ret = io_iter_do_read(rw, &s->iter);
+ if (ret == -EIOCBQUEUED)
+ return IOU_ISSUE_SKIP_COMPLETE;
+ /* we got some bytes, but not all. retry. */
+ kiocb->ki_flags &= ~IOCB_WAITQ;
+ iov_iter_restore(&s->iter, &s->iter_state);
+ } while (ret > 0);
+done:
+ kiocb_done(req, ret, issue_flags);
+out_free:
+ /* it's faster to check here then delegate to kfree */
+ if (iovec)
+ kfree(iovec);
+ return IOU_ISSUE_SKIP_COMPLETE;
+}
+
+int io_write(struct io_kiocb *req, unsigned int issue_flags)
+{
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+ struct io_rw_state __s, *s = &__s;
+ struct iovec *iovec;
+ struct kiocb *kiocb = &rw->kiocb;
+ bool force_nonblock = issue_flags & IO_URING_F_NONBLOCK;
+ ssize_t ret, ret2;
+ loff_t *ppos;
+
+ if (!req_has_async_data(req)) {
+ ret = io_import_iovec(WRITE, req, &iovec, s, issue_flags);
+ if (unlikely(ret < 0))
+ return ret;
+ } else {
+ struct io_async_rw *io = req->async_data;
+
+ s = &io->s;
+ iov_iter_restore(&s->iter, &s->iter_state);
+ iovec = NULL;
+ }
+ ret = io_rw_init_file(req, FMODE_WRITE);
+ if (unlikely(ret)) {
+ kfree(iovec);
+ return ret;
+ }
+ req->cqe.res = iov_iter_count(&s->iter);
+
+ if (force_nonblock) {
+ /* If the file doesn't support async, just async punt */
+ if (unlikely(!io_file_supports_nowait(req)))
+ goto copy_iov;
+
+ /* file path doesn't support NOWAIT for non-direct_IO */
+ if (force_nonblock && !(kiocb->ki_flags & IOCB_DIRECT) &&
+ (req->flags & REQ_F_ISREG))
+ goto copy_iov;
+
+ kiocb->ki_flags |= IOCB_NOWAIT;
+ } else {
+ /* Ensure we clear previously set non-block flag */
+ kiocb->ki_flags &= ~IOCB_NOWAIT;
+ }
+
+ ppos = io_kiocb_update_pos(req);
+
+ ret = rw_verify_area(WRITE, req->file, ppos, req->cqe.res);
+ if (unlikely(ret))
+ goto out_free;
+
+ /*
+ * Open-code file_start_write here to grab freeze protection,
+ * which will be released by another thread in
+ * io_complete_rw(). Fool lockdep by telling it the lock got
+ * released so that it doesn't complain about the held lock when
+ * we return to userspace.
+ */
+ if (req->flags & REQ_F_ISREG) {
+ sb_start_write(file_inode(req->file)->i_sb);
+ __sb_writers_release(file_inode(req->file)->i_sb,
+ SB_FREEZE_WRITE);
+ }
+ kiocb->ki_flags |= IOCB_WRITE;
+
+ if (likely(req->file->f_op->write_iter))
+ ret2 = call_write_iter(req->file, kiocb, &s->iter);
+ else if (req->file->f_op->write)
+ ret2 = loop_rw_iter(WRITE, rw, &s->iter);
+ else
+ ret2 = -EINVAL;
+
+ if (req->flags & REQ_F_REISSUE) {
+ req->flags &= ~REQ_F_REISSUE;
+ ret2 = -EAGAIN;
+ }
+
+ /*
+ * Raw bdev writes will return -EOPNOTSUPP for IOCB_NOWAIT. Just
+ * retry them without IOCB_NOWAIT.
+ */
+ if (ret2 == -EOPNOTSUPP && (kiocb->ki_flags & IOCB_NOWAIT))
+ ret2 = -EAGAIN;
+ /* no retry on NONBLOCK nor RWF_NOWAIT */
+ if (ret2 == -EAGAIN && (req->flags & REQ_F_NOWAIT))
+ goto done;
+ if (!force_nonblock || ret2 != -EAGAIN) {
+ /* IOPOLL retry should happen for io-wq threads */
+ if (ret2 == -EAGAIN && (req->ctx->flags & IORING_SETUP_IOPOLL))
+ goto copy_iov;
+done:
+ kiocb_done(req, ret2, issue_flags);
+ ret = IOU_ISSUE_SKIP_COMPLETE;
+ } else {
+copy_iov:
+ iov_iter_restore(&s->iter, &s->iter_state);
+ ret = io_setup_async_rw(req, iovec, s, false);
+ return ret ?: -EAGAIN;
+ }
+out_free:
+ /* it's reportedly faster than delegating the null check to kfree() */
+ if (iovec)
+ kfree(iovec);
+ return ret;
+}
+
+static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
+{
+ if (unlikely(ctx->off_timeout_used || ctx->drain_active ||
+ ctx->has_evfd))
+ __io_commit_cqring_flush(ctx);
+
+ if (ctx->flags & IORING_SETUP_SQPOLL)
+ io_cqring_wake(ctx);
+}
+
+int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin)
+{
+ struct io_wq_work_node *pos, *start, *prev;
+ unsigned int poll_flags = BLK_POLL_NOSLEEP;
+ DEFINE_IO_COMP_BATCH(iob);
+ int nr_events = 0;
+
+ /*
+ * Only spin for completions if we don't have multiple devices hanging
+ * off our complete list.
+ */
+ if (ctx->poll_multi_queue || force_nonspin)
+ poll_flags |= BLK_POLL_ONESHOT;
+
+ wq_list_for_each(pos, start, &ctx->iopoll_list) {
+ struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list);
+ struct io_rw *rw = io_kiocb_to_cmd(req);
+ int ret;
+
+ /*
+ * Move completed and retryable entries to our local lists.
+ * If we find a request that requires polling, break out
+ * and complete those lists first, if we have entries there.
+ */
+ if (READ_ONCE(req->iopoll_completed))
+ break;
+
+ ret = rw->kiocb.ki_filp->f_op->iopoll(&rw->kiocb, &iob, poll_flags);
+ if (unlikely(ret < 0))
+ return ret;
+ else if (ret)
+ poll_flags |= BLK_POLL_ONESHOT;
+
+ /* iopoll may have completed current req */
+ if (!rq_list_empty(iob.req_list) ||
+ READ_ONCE(req->iopoll_completed))
+ break;
+ }
+
+ if (!rq_list_empty(iob.req_list))
+ iob.complete(&iob);
+ else if (!pos)
+ return 0;
+
+ prev = start;
+ wq_list_for_each_resume(pos, prev) {
+ struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list);
+
+ /* order with io_complete_rw_iopoll(), e.g. ->result updates */
+ if (!smp_load_acquire(&req->iopoll_completed))
+ break;
+ nr_events++;
+ if (unlikely(req->flags & REQ_F_CQE_SKIP))
+ continue;
+
+ req->cqe.flags = io_put_kbuf(req, 0);
+ __io_fill_cqe_req(req->ctx, req);
+ }
+
+ if (unlikely(!nr_events))
+ return 0;
+
+ io_commit_cqring(ctx);
+ io_cqring_ev_posted_iopoll(ctx);
+ pos = start ? start->next : ctx->iopoll_list.first;
+ wq_list_cut(&ctx->iopoll_list, prev, start);
+ io_free_batch_list(ctx, pos);
+ return nr_events;
+}
projects / linux-2.6-microblaze.git / commitdiff