block: remove i_bdev
[linux-2.6-microblaze.git] / fs / io_uring.c
index b42dfa0..8f13c04 100644 (file)
@@ -995,20 +995,33 @@ static void io_sq_thread_drop_mm(void)
        if (mm) {
                kthread_unuse_mm(mm);
                mmput(mm);
+               current->mm = NULL;
        }
 }
 
 static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx)
 {
-       if (!current->mm) {
-               if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL) ||
-                            !ctx->sqo_task->mm ||
-                            !mmget_not_zero(ctx->sqo_task->mm)))
-                       return -EFAULT;
-               kthread_use_mm(ctx->sqo_task->mm);
+       struct mm_struct *mm;
+
+       if (current->mm)
+               return 0;
+
+       /* Should never happen */
+       if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL)))
+               return -EFAULT;
+
+       task_lock(ctx->sqo_task);
+       mm = ctx->sqo_task->mm;
+       if (unlikely(!mm || !mmget_not_zero(mm)))
+               mm = NULL;
+       task_unlock(ctx->sqo_task);
+
+       if (mm) {
+               kthread_use_mm(mm);
+               return 0;
        }
 
-       return 0;
+       return -EFAULT;
 }
 
 static int io_sq_thread_acquire_mm(struct io_ring_ctx *ctx,
@@ -1274,9 +1287,12 @@ static bool io_identity_cow(struct io_kiocb *req)
        /* add one for this request */
        refcount_inc(&id->count);
 
-       /* drop old identity, assign new one. one ref for req, one for tctx */
-       if (req->work.identity != tctx->identity &&
-           refcount_sub_and_test(2, &req->work.identity->count))
+       /* drop tctx and req identity references, if needed */
+       if (tctx->identity != &tctx->__identity &&
+           refcount_dec_and_test(&tctx->identity->count))
+               kfree(tctx->identity);
+       if (req->work.identity != &tctx->__identity &&
+           refcount_dec_and_test(&req->work.identity->count))
                kfree(req->work.identity);
 
        req->work.identity = id;
@@ -1365,6 +1381,9 @@ static void io_prep_async_work(struct io_kiocb *req)
        io_req_init_async(req);
        id = req->work.identity;
 
+       if (req->flags & REQ_F_FORCE_ASYNC)
+               req->work.flags |= IO_WQ_WORK_CONCURRENT;
+
        if (req->flags & REQ_F_ISREG) {
                if (def->hash_reg_file || (ctx->flags & IORING_SETUP_IOPOLL))
                        io_wq_hash_work(&req->work, file_inode(req->file));
@@ -1574,14 +1593,29 @@ static void io_cqring_mark_overflow(struct io_ring_ctx *ctx)
        }
 }
 
-static inline bool io_match_files(struct io_kiocb *req,
-                                      struct files_struct *files)
+static inline bool __io_match_files(struct io_kiocb *req,
+                                   struct files_struct *files)
 {
+       return ((req->flags & REQ_F_WORK_INITIALIZED) &&
+               (req->work.flags & IO_WQ_WORK_FILES)) &&
+               req->work.identity->files == files;
+}
+
+static bool io_match_files(struct io_kiocb *req,
+                          struct files_struct *files)
+{
+       struct io_kiocb *link;
+
        if (!files)
                return true;
-       if ((req->flags & REQ_F_WORK_INITIALIZED) &&
-           (req->work.flags & IO_WQ_WORK_FILES))
-               return req->work.identity->files == files;
+       if (__io_match_files(req, files))
+               return true;
+       if (req->flags & REQ_F_LINK_HEAD) {
+               list_for_each_entry(link, &req->link_list, link_list) {
+                       if (__io_match_files(link, files))
+                               return true;
+               }
+       }
        return false;
 }
 
@@ -1665,7 +1699,8 @@ static void __io_cqring_fill_event(struct io_kiocb *req, long res, long cflags)
                WRITE_ONCE(cqe->user_data, req->user_data);
                WRITE_ONCE(cqe->res, res);
                WRITE_ONCE(cqe->flags, cflags);
-       } else if (ctx->cq_overflow_flushed || req->task->io_uring->in_idle) {
+       } else if (ctx->cq_overflow_flushed ||
+                  atomic_read(&req->task->io_uring->in_idle)) {
                /*
                 * If we're in ring overflow flush mode, or in task cancel mode,
                 * then we cannot store the request for later flushing, we need
@@ -1835,7 +1870,7 @@ static void __io_free_req(struct io_kiocb *req)
        io_dismantle_req(req);
 
        percpu_counter_dec(&tctx->inflight);
-       if (tctx->in_idle)
+       if (atomic_read(&tctx->in_idle))
                wake_up(&tctx->wait);
        put_task_struct(req->task);
 
@@ -1846,59 +1881,39 @@ static void __io_free_req(struct io_kiocb *req)
        percpu_ref_put(&ctx->refs);
 }
 
-static bool io_link_cancel_timeout(struct io_kiocb *req)
+static void io_kill_linked_timeout(struct io_kiocb *req)
 {
-       struct io_timeout_data *io = req->async_data;
        struct io_ring_ctx *ctx = req->ctx;
-       int ret;
-
-       ret = hrtimer_try_to_cancel(&io->timer);
-       if (ret != -1) {
-               io_cqring_fill_event(req, -ECANCELED);
-               io_commit_cqring(ctx);
-               req->flags &= ~REQ_F_LINK_HEAD;
-               io_put_req_deferred(req, 1);
-               return true;
-       }
-
-       return false;
-}
-
-static bool __io_kill_linked_timeout(struct io_kiocb *req)
-{
        struct io_kiocb *link;
-       bool wake_ev;
+       bool cancelled = false;
+       unsigned long flags;
 
-       if (list_empty(&req->link_list))
-               return false;
-       link = list_first_entry(&req->link_list, struct io_kiocb, link_list);
-       if (link->opcode != IORING_OP_LINK_TIMEOUT)
-               return false;
+       spin_lock_irqsave(&ctx->completion_lock, flags);
+       link = list_first_entry_or_null(&req->link_list, struct io_kiocb,
+                                       link_list);
        /*
         * Can happen if a linked timeout fired and link had been like
         * req -> link t-out -> link t-out [-> ...]
         */
-       if (!(link->flags & REQ_F_LTIMEOUT_ACTIVE))
-               return false;
+       if (link && (link->flags & REQ_F_LTIMEOUT_ACTIVE)) {
+               struct io_timeout_data *io = link->async_data;
+               int ret;
 
-       list_del_init(&link->link_list);
-       wake_ev = io_link_cancel_timeout(link);
+               list_del_init(&link->link_list);
+               ret = hrtimer_try_to_cancel(&io->timer);
+               if (ret != -1) {
+                       io_cqring_fill_event(link, -ECANCELED);
+                       io_commit_cqring(ctx);
+                       cancelled = true;
+               }
+       }
        req->flags &= ~REQ_F_LINK_TIMEOUT;
-       return wake_ev;
-}
-
-static void io_kill_linked_timeout(struct io_kiocb *req)
-{
-       struct io_ring_ctx *ctx = req->ctx;
-       unsigned long flags;
-       bool wake_ev;
-
-       spin_lock_irqsave(&ctx->completion_lock, flags);
-       wake_ev = __io_kill_linked_timeout(req);
        spin_unlock_irqrestore(&ctx->completion_lock, flags);
 
-       if (wake_ev)
+       if (cancelled) {
                io_cqring_ev_posted(ctx);
+               io_put_req(link);
+       }
 }
 
 static struct io_kiocb *io_req_link_next(struct io_kiocb *req)
@@ -2701,11 +2716,7 @@ static struct file *__io_file_get(struct io_submit_state *state, int fd)
 
 static bool io_bdev_nowait(struct block_device *bdev)
 {
-#ifdef CONFIG_BLOCK
        return !bdev || blk_queue_nowait(bdev_get_queue(bdev));
-#else
-       return true;
-#endif
 }
 
 /*
@@ -2718,14 +2729,16 @@ static bool io_file_supports_async(struct file *file, int rw)
        umode_t mode = file_inode(file)->i_mode;
 
        if (S_ISBLK(mode)) {
-               if (io_bdev_nowait(file->f_inode->i_bdev))
+               if (IS_ENABLED(CONFIG_BLOCK) &&
+                   io_bdev_nowait(I_BDEV(file->f_mapping->host)))
                        return true;
                return false;
        }
        if (S_ISCHR(mode) || S_ISSOCK(mode))
                return true;
        if (S_ISREG(mode)) {
-               if (io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&
+               if (IS_ENABLED(CONFIG_BLOCK) &&
+                   io_bdev_nowait(file->f_inode->i_sb->s_bdev) &&
                    file->f_op != &io_uring_fops)
                        return true;
                return false;
@@ -3532,8 +3545,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock,
         * we return to userspace.
         */
        if (req->flags & REQ_F_ISREG) {
-               __sb_start_write(file_inode(req->file)->i_sb,
-                                       SB_FREEZE_WRITE, true);
+               sb_start_write(file_inode(req->file)->i_sb);
                __sb_writers_release(file_inode(req->file)->i_sb,
                                        SB_FREEZE_WRITE);
        }
@@ -4977,8 +4989,10 @@ static int io_poll_double_wake(struct wait_queue_entry *wait, unsigned mode,
                /* make sure double remove sees this as being gone */
                wait->private = NULL;
                spin_unlock(&poll->head->lock);
-               if (!done)
-                       __io_async_wake(req, poll, mask, io_poll_task_func);
+               if (!done) {
+                       /* use wait func handler, so it matches the rq type */
+                       poll->wait.func(&poll->wait, mode, sync, key);
+               }
        }
        refcount_dec(&req->refs);
        return 1;
@@ -6180,7 +6194,6 @@ static struct io_kiocb *io_prep_linked_timeout(struct io_kiocb *req)
 static void __io_queue_sqe(struct io_kiocb *req, struct io_comp_state *cs)
 {
        struct io_kiocb *linked_timeout;
-       struct io_kiocb *nxt;
        const struct cred *old_creds = NULL;
        int ret;
 
@@ -6206,7 +6219,6 @@ again:
         */
        if (ret == -EAGAIN && !(req->flags & REQ_F_NOWAIT)) {
                if (!io_arm_poll_handler(req)) {
-punt:
                        /*
                         * Queued up for async execution, worker will release
                         * submit reference when the iocb is actually submitted.
@@ -6216,33 +6228,25 @@ punt:
 
                if (linked_timeout)
                        io_queue_linked_timeout(linked_timeout);
-               goto exit;
-       }
+       } else if (likely(!ret)) {
+               /* drop submission reference */
+               req = io_put_req_find_next(req);
+               if (linked_timeout)
+                       io_queue_linked_timeout(linked_timeout);
 
-       if (unlikely(ret)) {
+               if (req) {
+                       if (!(req->flags & REQ_F_FORCE_ASYNC))
+                               goto again;
+                       io_queue_async_work(req);
+               }
+       } else {
                /* un-prep timeout, so it'll be killed as any other linked */
                req->flags &= ~REQ_F_LINK_TIMEOUT;
                req_set_fail_links(req);
                io_put_req(req);
                io_req_complete(req, ret);
-               goto exit;
        }
 
-       /* drop submission reference */
-       nxt = io_put_req_find_next(req);
-       if (linked_timeout)
-               io_queue_linked_timeout(linked_timeout);
-
-       if (nxt) {
-               req = nxt;
-
-               if (req->flags & REQ_F_FORCE_ASYNC) {
-                       linked_timeout = NULL;
-                       goto punt;
-               }
-               goto again;
-       }
-exit:
        if (old_creds)
                revert_creds(old_creds);
 }
@@ -6266,13 +6270,6 @@ fail_req:
                        if (unlikely(ret))
                                goto fail_req;
                }
-
-               /*
-                * Never try inline submit of IOSQE_ASYNC is set, go straight
-                * to async execution.
-                */
-               io_req_init_async(req);
-               req->work.flags |= IO_WQ_WORK_CONCURRENT;
                io_queue_async_work(req);
        } else {
                if (sqe) {
@@ -7727,7 +7724,8 @@ static int io_uring_alloc_task_context(struct task_struct *task)
        xa_init(&tctx->xa);
        init_waitqueue_head(&tctx->wait);
        tctx->last = NULL;
-       tctx->in_idle = 0;
+       atomic_set(&tctx->in_idle, 0);
+       tctx->sqpoll = false;
        io_init_identity(&tctx->__identity);
        tctx->identity = &tctx->__identity;
        task->io_uring = tctx;
@@ -8420,22 +8418,6 @@ static bool io_match_link(struct io_kiocb *preq, struct io_kiocb *req)
        return false;
 }
 
-static bool io_match_link_files(struct io_kiocb *req,
-                               struct files_struct *files)
-{
-       struct io_kiocb *link;
-
-       if (io_match_files(req, files))
-               return true;
-       if (req->flags & REQ_F_LINK_HEAD) {
-               list_for_each_entry(link, &req->link_list, link_list) {
-                       if (io_match_files(link, files))
-                               return true;
-               }
-       }
-       return false;
-}
-
 /*
  * We're looking to cancel 'req' because it's holding on to our files, but
  * 'req' could be a link to another request. See if it is, and cancel that
@@ -8485,7 +8467,21 @@ static bool io_timeout_remove_link(struct io_ring_ctx *ctx,
 
 static bool io_cancel_link_cb(struct io_wq_work *work, void *data)
 {
-       return io_match_link(container_of(work, struct io_kiocb, work), data);
+       struct io_kiocb *req = container_of(work, struct io_kiocb, work);
+       bool ret;
+
+       if (req->flags & REQ_F_LINK_TIMEOUT) {
+               unsigned long flags;
+               struct io_ring_ctx *ctx = req->ctx;
+
+               /* protect against races with linked timeouts */
+               spin_lock_irqsave(&ctx->completion_lock, flags);
+               ret = io_match_link(req, data);
+               spin_unlock_irqrestore(&ctx->completion_lock, flags);
+       } else {
+               ret = io_match_link(req, data);
+       }
+       return ret;
 }
 
 static void io_attempt_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req)
@@ -8511,6 +8507,7 @@ static void io_attempt_cancel(struct io_ring_ctx *ctx, struct io_kiocb *req)
 }
 
 static void io_cancel_defer_files(struct io_ring_ctx *ctx,
+                                 struct task_struct *task,
                                  struct files_struct *files)
 {
        struct io_defer_entry *de = NULL;
@@ -8518,7 +8515,8 @@ static void io_cancel_defer_files(struct io_ring_ctx *ctx,
 
        spin_lock_irq(&ctx->completion_lock);
        list_for_each_entry_reverse(de, &ctx->defer_list, list) {
-               if (io_match_link_files(de->req, files)) {
+               if (io_task_match(de->req, task) &&
+                   io_match_files(de->req, files)) {
                        list_cut_position(&list, &ctx->defer_list, &de->list);
                        break;
                }
@@ -8544,7 +8542,6 @@ static bool io_uring_cancel_files(struct io_ring_ctx *ctx,
        if (list_empty_careful(&ctx->inflight_list))
                return false;
 
-       io_cancel_defer_files(ctx, files);
        /* cancel all at once, should be faster than doing it one by one*/
        io_wq_cancel_cb(ctx->io_wq, io_wq_files_match, files, true);
 
@@ -8630,8 +8627,16 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
 {
        struct task_struct *task = current;
 
-       if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data)
+       if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
                task = ctx->sq_data->thread;
+               atomic_inc(&task->io_uring->in_idle);
+               io_sq_thread_park(ctx->sq_data);
+       }
+
+       if (files)
+               io_cancel_defer_files(ctx, NULL, files);
+       else
+               io_cancel_defer_files(ctx, task, NULL);
 
        io_cqring_overflow_flush(ctx, true, task, files);
 
@@ -8639,12 +8644,23 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
                io_run_task_work();
                cond_resched();
        }
+
+       if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
+               atomic_dec(&task->io_uring->in_idle);
+               /*
+                * If the files that are going away are the ones in the thread
+                * identity, clear them out.
+                */
+               if (task->io_uring->identity->files == files)
+                       task->io_uring->identity->files = NULL;
+               io_sq_thread_unpark(ctx->sq_data);
+       }
 }
 
 /*
  * Note that this task has used io_uring. We use it for cancelation purposes.
  */
-static int io_uring_add_task_file(struct file *file)
+static int io_uring_add_task_file(struct io_ring_ctx *ctx, struct file *file)
 {
        struct io_uring_task *tctx = current->io_uring;
 
@@ -8666,6 +8682,14 @@ static int io_uring_add_task_file(struct file *file)
                tctx->last = file;
        }
 
+       /*
+        * This is race safe in that the task itself is doing this, hence it
+        * cannot be going through the exit/cancel paths at the same time.
+        * This cannot be modified while exit/cancel is running.
+        */
+       if (!tctx->sqpoll && (ctx->flags & IORING_SETUP_SQPOLL))
+               tctx->sqpoll = true;
+
        return 0;
 }
 
@@ -8707,7 +8731,7 @@ void __io_uring_files_cancel(struct files_struct *files)
        unsigned long index;
 
        /* make sure overflow events are dropped */
-       tctx->in_idle = true;
+       atomic_inc(&tctx->in_idle);
 
        xa_for_each(&tctx->xa, index, file) {
                struct io_ring_ctx *ctx = file->private_data;
@@ -8716,6 +8740,35 @@ void __io_uring_files_cancel(struct files_struct *files)
                if (files)
                        io_uring_del_task_file(file);
        }
+
+       atomic_dec(&tctx->in_idle);
+}
+
+static s64 tctx_inflight(struct io_uring_task *tctx)
+{
+       unsigned long index;
+       struct file *file;
+       s64 inflight;
+
+       inflight = percpu_counter_sum(&tctx->inflight);
+       if (!tctx->sqpoll)
+               return inflight;
+
+       /*
+        * If we have SQPOLL rings, then we need to iterate and find them, and
+        * add the pending count for those.
+        */
+       xa_for_each(&tctx->xa, index, file) {
+               struct io_ring_ctx *ctx = file->private_data;
+
+               if (ctx->flags & IORING_SETUP_SQPOLL) {
+                       struct io_uring_task *__tctx = ctx->sqo_task->io_uring;
+
+                       inflight += percpu_counter_sum(&__tctx->inflight);
+               }
+       }
+
+       return inflight;
 }
 
 /*
@@ -8729,11 +8782,11 @@ void __io_uring_task_cancel(void)
        s64 inflight;
 
        /* make sure overflow events are dropped */
-       tctx->in_idle = true;
+       atomic_inc(&tctx->in_idle);
 
        do {
                /* read completions before cancelations */
-               inflight = percpu_counter_sum(&tctx->inflight);
+               inflight = tctx_inflight(tctx);
                if (!inflight)
                        break;
                __io_uring_files_cancel(NULL);
@@ -8744,13 +8797,13 @@ void __io_uring_task_cancel(void)
                 * If we've seen completions, retry. This avoids a race where
                 * a completion comes in before we did prepare_to_wait().
                 */
-               if (inflight != percpu_counter_sum(&tctx->inflight))
+               if (inflight != tctx_inflight(tctx))
                        continue;
                schedule();
        } while (1);
 
        finish_wait(&tctx->wait, &wait);
-       tctx->in_idle = false;
+       atomic_dec(&tctx->in_idle);
 }
 
 static int io_uring_flush(struct file *file, void *data)
@@ -8895,7 +8948,7 @@ SYSCALL_DEFINE6(io_uring_enter, unsigned int, fd, u32, to_submit,
                        io_sqpoll_wait_sq(ctx);
                submitted = to_submit;
        } else if (to_submit) {
-               ret = io_uring_add_task_file(f.file);
+               ret = io_uring_add_task_file(ctx, f.file);
                if (unlikely(ret))
                        goto out;
                mutex_lock(&ctx->uring_lock);
@@ -8932,7 +8985,8 @@ out_fput:
 #ifdef CONFIG_PROC_FS
 static int io_uring_show_cred(int id, void *p, void *data)
 {
-       const struct cred *cred = p;
+       struct io_identity *iod = p;
+       const struct cred *cred = iod->creds;
        struct seq_file *m = data;
        struct user_namespace *uns = seq_user_ns(m);
        struct group_info *gi;
@@ -9124,7 +9178,7 @@ err_fd:
 #if defined(CONFIG_UNIX)
        ctx->ring_sock->file = file;
 #endif
-       if (unlikely(io_uring_add_task_file(file))) {
+       if (unlikely(io_uring_add_task_file(ctx, file))) {
                file = ERR_PTR(-ENOMEM);
                goto err_fd;
        }
@@ -9169,6 +9223,7 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p,
                 * to a power-of-two, if it isn't already. We do NOT impose
                 * any cq vs sq ring sizing.
                 */
+               p->cq_entries = roundup_pow_of_two(p->cq_entries);
                if (p->cq_entries < p->sq_entries)
                        return -EINVAL;
                if (p->cq_entries > IORING_MAX_CQ_ENTRIES) {
@@ -9176,7 +9231,6 @@ static int io_uring_create(unsigned entries, struct io_uring_params *p,
                                return -EINVAL;
                        p->cq_entries = IORING_MAX_CQ_ENTRIES;
                }
-               p->cq_entries = roundup_pow_of_two(p->cq_entries);
        } else {
                p->cq_entries = 2 * p->sq_entries;
        }