-- Suparna Bhattacharya (suparna@in.ibm.com) Linux Technology Center IBM Software Labs, India
diff -ur linux-2.5.66/fs/aio.c linux-2.5.66aio/fs/aio.c --- linux-2.5.66/fs/aio.c Tue Mar 25 03:30:22 2003 +++ linux-2.5.66aio/fs/aio.c Wed Mar 26 20:25:02 2003 @@ -395,6 +396,7 @@ req->ki_cancel = NULL; req->ki_retry = NULL; req->ki_user_obj = NULL; + INIT_LIST_HEAD(&req->ki_run_list); /* Check if the completion queue has enough free space to * accept an event from this io. @@ -558,46 +560,124 @@ enter_lazy_tlb(mm, current, smp_processor_id()); } -/* Run on kevent's context. FIXME: needs to be per-cpu and warn if an - * operation blocks. - */ -static void aio_kick_handler(void *data) +static inline int __queue_kicked_iocb(struct kiocb *iocb) { - struct kioctx *ctx = data; + struct kioctx *ctx = iocb->ki_ctx; - use_mm(ctx->mm); + if (list_empty(&iocb->ki_run_list)) { + list_add_tail(&iocb->ki_run_list, + &ctx->run_list); + return 1; + } + return 0; +} - spin_lock_irq(&ctx->ctx_lock); - while (!list_empty(&ctx->run_list)) { - struct kiocb *iocb; - long ret; +/* Expects to be called with iocb->ki_ctx->lock held */ +static ssize_t aio_run_iocb(struct kiocb *iocb) +{ + struct kioctx *ctx = iocb->ki_ctx; + ssize_t (*retry)(struct kiocb *); + ssize_t ret; - iocb = list_entry(ctx->run_list.next, struct kiocb, - ki_run_list); - list_del(&iocb->ki_run_list); - iocb->ki_users ++; - spin_unlock_irq(&ctx->ctx_lock); + if (iocb->ki_retried++ > 1024*1024) { + printk("Maximal retry count. Bytes done %d\n", + iocb->ki_nbytes - iocb->ki_left); + return -EAGAIN; + } + + if (!(iocb->ki_retried & 0xff)) { + printk("%ld aio retries completed %d bytes of %d\n", + iocb->ki_retried, + iocb->ki_nbytes - iocb->ki_left, iocb->ki_nbytes); + } + + if (!(retry = iocb->ki_retry)) { + printk("aio_run_iocb: iocb->ki_retry = NULL\n"); + return 0; + } + + iocb->ki_users ++; + kiocbClearKicked(iocb); + iocb->ki_run_list.next = iocb->ki_run_list.prev = NULL; + iocb->ki_retry = NULL; + spin_unlock_irq(&ctx->ctx_lock); + + BUG_ON(current->iocb != NULL); + + current->iocb = iocb; + ret = retry(iocb); + current->iocb = NULL; - kiocbClearKicked(iocb); - ret = iocb->ki_retry(iocb); - if (-EIOCBQUEUED != ret) { + if (-EIOCBQUEUED != ret) { + if (list_empty(&iocb->ki_wait.task_list)) aio_complete(iocb, ret, 0); - iocb = NULL; - } + else + printk("can't delete iocb in use\n"); + } else { + if (list_empty(&iocb->ki_wait.task_list)) + kiocbSetKicked(iocb); + } + spin_lock_irq(&ctx->ctx_lock); - spin_lock_irq(&ctx->ctx_lock); - if (NULL != iocb) - __aio_put_req(ctx, iocb); + iocb->ki_retry = retry; + INIT_LIST_HEAD(&iocb->ki_run_list); + if (kiocbIsKicked(iocb)) { + BUG_ON(ret != -EIOCBQUEUED); + __queue_kicked_iocb(iocb); + } + __aio_put_req(ctx, iocb); + return ret; +} + +static void aio_run_iocbs(struct kioctx *ctx) +{ + struct kiocb *iocb; + ssize_t ret; + + spin_lock_irq(&ctx->ctx_lock); + while (!list_empty(&ctx->run_list)) { + iocb = list_entry(ctx->run_list.next, struct kiocb, + ki_run_list); + list_del(&iocb->ki_run_list); + ret = aio_run_iocb(iocb); } spin_unlock_irq(&ctx->ctx_lock); +} + +/* Run on aiod/kevent's context. FIXME: needs to be per-cpu and warn if an + * operation blocks. + */ +static void aio_kick_handler(void *data) +{ + struct kioctx *ctx = data; + use_mm(ctx->mm); + aio_run_iocbs(ctx); unuse_mm(ctx->mm); } -void kick_iocb(struct kiocb *iocb) + +void queue_kicked_iocb(struct kiocb *iocb) { struct kioctx *ctx = iocb->ki_ctx; + unsigned long flags; + int run = 0; + + WARN_ON((!list_empty(&iocb->ki_wait.task_list))); + + spin_lock_irqsave(&ctx->ctx_lock, flags); + run = __queue_kicked_iocb(iocb); + spin_unlock_irqrestore(&ctx->ctx_lock, flags); + if (run) { + if (waitqueue_active(&ctx->wait)) + wake_up(&ctx->wait); + else + queue_work(aio_wq, &ctx->wq); + } +} +void kick_iocb(struct kiocb *iocb) +{ /* sync iocbs are easy: they can only ever be executing from a * single context. */ if (is_sync_kiocb(iocb)) { @@ -607,11 +687,9 @@ } if (!kiocbTryKick(iocb)) { - unsigned long flags; - spin_lock_irqsave(&ctx->ctx_lock, flags); - list_add_tail(&iocb->ki_run_list, &ctx->run_list); - spin_unlock_irqrestore(&ctx->ctx_lock, flags); - schedule_work(&ctx->wq); + queue_kicked_iocb(iocb); + } else { + pr_debug("iocb already kicked or in progress\n"); } } @@ -642,13 +720,13 @@ iocb->ki_user_data = res; if (iocb->ki_users == 1) { iocb->ki_users = 0; - return 1; + ret = 1; + } else { + spin_lock_irq(&ctx->ctx_lock); + iocb->ki_users--; + ret = (0 == iocb->ki_users); + spin_unlock_irq(&ctx->ctx_lock); } - spin_lock_irq(&ctx->ctx_lock); - iocb->ki_users--; - ret = (0 == iocb->ki_users); - spin_unlock_irq(&ctx->ctx_lock); - /* sync iocbs put the task here for us */ wake_up_process(iocb->ki_user_obj); return ret; @@ -664,6 +742,9 @@ */ spin_lock_irqsave(&ctx->ctx_lock, flags); + if (iocb->ki_run_list.prev && !list_empty(&iocb->ki_run_list)) + list_del_init(&iocb->ki_run_list); + ring = kmap_atomic(info->ring_pages[0], KM_IRQ1); tail = info->tail; @@ -865,6 +946,8 @@ ret = 0; if (to.timed_out) /* Only check after read evt */ break; + /* accelerate kicked iocbs for this ctx */ + aio_run_iocbs(ctx); schedule(); if (signal_pending(tsk)) { ret = -EINTR; @@ -984,6 +1067,149 @@ return -EINVAL; } +ssize_t aio_pread(struct kiocb *iocb) +{ + struct file *file = iocb->ki_filp; + ssize_t ret = 0; + + ret = file->f_op->aio_read(iocb, iocb->ki_buf, + iocb->ki_left, iocb->ki_pos); + + pr_debug("aio_pread: fop ret %d\n", ret); + + /* + * Can't just depend on iocb->ki_left to determine + * whether we are done. This may have been a short read. + */ + if (ret > 0) { + iocb->ki_buf += ret; + iocb->ki_left -= ret; + + ret = -EIOCBQUEUED; + } + + /* This means we must have transferred all that we could */ + /* No need to retry anymore */ + if (ret == 0) + ret = iocb->ki_nbytes - iocb->ki_left; + + return ret; +} + +ssize_t aio_pwrite(struct kiocb *iocb) +{ + struct file *file = iocb->ki_filp; + ssize_t ret = 0; + + ret = file->f_op->aio_write(iocb, iocb->ki_buf, + iocb->ki_left, iocb->ki_pos); + + pr_debug("aio_pread: fop ret %d\n", ret); + + /* + * TBD: Even if iocb->ki_left = 0, could we need to + * wait for data to be sync'd ? Or can we assume + * that aio_fdsync/aio_fsync would be called explicitly + * as required. + */ + if (ret > 0) { + iocb->ki_buf += ret; + iocb->ki_left -= ret; + + ret = -EIOCBQUEUED; + } + + /* This means we must have transferred all that we could */ + /* No need to retry anymore */ + if (ret == 0) + ret = iocb->ki_nbytes - iocb->ki_left; + + return ret; +} + +ssize_t aio_fdsync(struct kiocb *iocb) +{ + struct file *file = iocb->ki_filp; + ssize_t ret = -EINVAL; + + if (file->f_op->aio_fsync) + ret = file->f_op->aio_fsync(iocb, 1); + return ret; +} + +ssize_t aio_fsync(struct kiocb *iocb) +{ + struct file *file = iocb->ki_filp; + ssize_t ret = -EINVAL; + + if (file->f_op->aio_fsync) + ret = file->f_op->aio_fsync(iocb, 0); + return ret; +} + +/* Called during initial submission and subsequent retry operations */ +ssize_t aio_setup_iocb(struct kiocb *iocb) +{ + struct file *file = iocb->ki_filp; + ssize_t ret = 0; + + switch (iocb->ki_opcode) { + case IOCB_CMD_PREAD: + ret = -EBADF; + if (unlikely(!(file->f_mode & FMODE_READ))) + break; + ret = -EFAULT; + if (unlikely(!access_ok(VERIFY_WRITE, iocb->ki_buf, + iocb->ki_left))) + break; + ret = -EINVAL; + if (file->f_op->aio_read) + iocb->ki_retry = aio_pread; + break; + case IOCB_CMD_PWRITE: + ret = -EBADF; + if (unlikely(!(file->f_mode & FMODE_WRITE))) + break; + ret = -EFAULT; + if (unlikely(!access_ok(VERIFY_READ, iocb->ki_buf, + iocb->ki_left))) + break; + ret = -EINVAL; + if (file->f_op->aio_write) + iocb->ki_retry = aio_pwrite; + break; + case IOCB_CMD_FDSYNC: + ret = -EINVAL; + if (file->f_op->aio_fsync) + iocb->ki_retry = aio_fdsync; + break; + case IOCB_CMD_FSYNC: + ret = -EINVAL; + if (file->f_op->aio_fsync) + iocb->ki_retry = aio_fsync; + break; + default: + dprintk("EINVAL: io_submit: no operation provided\n"); + ret = -EINVAL; + } + + if (!iocb->ki_retry) + return ret; + + pr_debug("ki_pos = %llu\n", iocb->ki_pos); + + return 0; +} + +int aio_wake_function(wait_queue_t *wait, unsigned mode, int sync) +{ + struct kiocb *iocb = container_of(wait, struct kiocb, ki_wait); + + list_del_init(&wait->task_list); + kick_iocb(iocb); + return 1; +} + static int FASTCALL(io_submit_one(struct kioctx *ctx, struct iocb *user_iocb, struct iocb *iocb)); static int io_submit_one(struct kioctx *ctx, struct iocb *user_iocb, @@ -992,7 +1218,6 @@ struct kiocb *req; struct file *file; ssize_t ret; - char *buf; /* enforce forwards compatibility on users */ if (unlikely(iocb->aio_reserved1 || iocb->aio_reserved2 || @@ -1033,51 +1258,27 @@ req->ki_user_data = iocb->aio_data; req->ki_pos = iocb->aio_offset; - buf = (char *)(unsigned long)iocb->aio_buf; + req->ki_buf = (char *)(unsigned long)iocb->aio_buf; + req->ki_left = req->ki_nbytes = iocb->aio_nbytes; + req->ki_opcode = iocb->aio_lio_opcode; + init_waitqueue_func_entry(&req->ki_wait, aio_wake_function); + INIT_LIST_HEAD(&req->ki_wait.task_list); + req->ki_run_list.next = req->ki_run_list.prev = NULL; + req->ki_retry = NULL; + req->ki_retried = 0; - switch (iocb->aio_lio_opcode) { - case IOCB_CMD_PREAD: - ret = -EBADF; - if (unlikely(!(file->f_mode & FMODE_READ))) - goto out_put_req; - ret = -EFAULT; - if (unlikely(!access_ok(VERIFY_WRITE, buf, iocb->aio_nbytes))) - goto out_put_req; - ret = -EINVAL; - if (file->f_op->aio_read) - ret = file->f_op->aio_read(req, buf, - iocb->aio_nbytes, req->ki_pos); - break; - case IOCB_CMD_PWRITE: - ret = -EBADF; - if (unlikely(!(file->f_mode & FMODE_WRITE))) - goto out_put_req; - ret = -EFAULT; - if (unlikely(!access_ok(VERIFY_READ, buf, iocb->aio_nbytes))) - goto out_put_req; - ret = -EINVAL; - if (file->f_op->aio_write) - ret = file->f_op->aio_write(req, buf, - iocb->aio_nbytes, req->ki_pos); - break; - case IOCB_CMD_FDSYNC: - ret = -EINVAL; - if (file->f_op->aio_fsync) - ret = file->f_op->aio_fsync(req, 1); - break; - case IOCB_CMD_FSYNC: - ret = -EINVAL; - if (file->f_op->aio_fsync) - ret = file->f_op->aio_fsync(req, 0); - break; - default: - dprintk("EINVAL: io_submit: no operation provided\n"); - ret = -EINVAL; - } + ret = aio_setup_iocb(req); + + if ((-EBADF == ret) || (-EFAULT == ret)) + goto out_put_req; + + spin_lock_irq(&ctx->ctx_lock); + ret = aio_run_iocb(req); + spin_unlock_irq(&ctx->ctx_lock); + + if (-EIOCBQUEUED == ret) + queue_work(aio_wq, &ctx->wq); - if (likely(-EIOCBQUEUED == ret)) - return 0; - aio_complete(req, ret, 0); return 0; out_put_req: diff -ur linux-2.5.66/include/linux/aio.h linux-2.5.66aio/include/linux/aio.h --- linux-2.5.66/include/linux/aio.h Tue Mar 25 03:29:54 2003 +++ linux-2.5.66aio/include/linux/aio.h Wed Mar 26 18:46:18 2003 @@ -54,7 +54,7 @@ struct file *ki_filp; struct kioctx *ki_ctx; /* may be NULL for sync ops */ int (*ki_cancel)(struct kiocb *, struct io_event *); - long (*ki_retry)(struct kiocb *); + ssize_t (*ki_retry)(struct kiocb *); struct list_head ki_list; /* the aio core uses this * for cancellation */ @@ -62,6 +62,14 @@ void *ki_user_obj; /* pointer to userland's iocb */ __u64 ki_user_data; /* user's data for completion */ loff_t ki_pos; + + /* State that we remember to be able to restart/retry */ + unsigned short ki_opcode; + size_t ki_nbytes; /* copy of iocb->aio_nbytes */ + char *ki_buf; /* remaining iocb->aio_buf */ + size_t ki_left; /* remaining bytes */ + wait_queue_t ki_wait; + long ki_retried; /* just for testing */ char private[KIOCB_PRIVATE_SIZE]; }; @@ -77,6 +85,8 @@ (x)->ki_ctx = &tsk->active_mm->default_kioctx; \ (x)->ki_cancel = NULL; \ (x)->ki_user_obj = tsk; \ + (x)->ki_user_data = 0; \ + init_wait((&(x)->ki_wait)); \ } while (0) #define AIO_RING_MAGIC 0xa10a10a1 @@ -151,6 +161,13 @@ #define get_ioctx(kioctx) do { if (unlikely(atomic_read(&(kioctx)->users) <= 0)) BUG(); atomic_inc(&(kioctx)->users); } while (0) #define put_ioctx(kioctx) do { if (unlikely(atomic_dec_and_test(&(kioctx)->users))) __put_ioctx(kioctx); else if (unlikely(atomic_read(&(kioctx)->users) < 0)) BUG(); } while (0) +#define do_sync_op(op) do { \ + struct kiocb *iocb = current->iocb; \ + current->iocb = NULL; \ + op; \ + current->iocb = iocb; \ + } while (0); + #include <linux/aio_abi.h> static inline struct kiocb *list_kiocb(struct list_head *h) diff -ur linux-2.5.66/include/linux/init_task.h linux-2.5.66aio/include/linux/init_task.h --- linux-2.5.66/include/linux/init_task.h Tue Mar 25 03:30:00 2003 +++ linux-2.5.66aio/include/linux/init_task.h Fri Mar 21 14:50:42 2003 @@ -103,6 +103,7 @@ .alloc_lock = SPIN_LOCK_UNLOCKED, \ .switch_lock = SPIN_LOCK_UNLOCKED, \ .journal_info = NULL, \ + .iocb = NULL, \ } diff -ur linux-2.5.66/include/linux/sched.h linux-2.5.66aio/include/linux/sched.h --- linux-2.5.66/include/linux/sched.h Tue Mar 25 03:30:00 2003 +++ linux-2.5.66aio/include/linux/sched.h Fri Mar 21 14:50:42 2003 @@ -438,6 +438,8 @@ unsigned long ptrace_message; siginfo_t *last_siginfo; /* For ptrace use. */ +/* current aio handle */ + struct kiocb *iocb; }; extern void __put_task_struct(struct task_struct *tsk); diff -ur linux-2.5.66/kernel/fork.c linux-2.5.66aio/kernel/fork.c --- linux-2.5.66/kernel/fork.c Tue Mar 25 03:30:00 2003 +++ linux-2.5.66aio/kernel/fork.c Wed Mar 26 18:32:24 2003 @@ -856,6 +856,7 @@ p->lock_depth = -1; /* -1 = no lock */ p->start_time = get_jiffies_64(); p->security = NULL; + p->iocb = NULL; retval = -ENOMEM; if (security_task_alloc(p)) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/