*
* See ../COPYING for licensing terms.
*/
+#define pr_fmt(fmt) "%s: " fmt, __func__
+
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/time.h>
#include <linux/aio_abi.h>
-#include <linux/module.h>
+#include <linux/export.h>
#include <linux/syscalls.h>
+#include <linux/backing-dev.h>
#include <linux/uio.h>
-#define DEBUG 0
-
#include <linux/sched.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/mman.h>
+#include <linux/mmu_context.h>
#include <linux/slab.h>
#include <linux/timer.h>
#include <linux/aio.h>
#include <linux/workqueue.h>
#include <linux/security.h>
#include <linux/eventfd.h>
+#include <linux/blkdev.h>
+#include <linux/compat.h>
#include <asm/kmap_types.h>
#include <asm/uaccess.h>
-#include <asm/mmu_context.h>
-#if DEBUG > 1
-#define dprintk printk
-#else
-#define dprintk(x...) do { ; } while (0)
-#endif
+#define AIO_RING_MAGIC 0xa10a10a1
+#define AIO_RING_COMPAT_FEATURES 1
+#define AIO_RING_INCOMPAT_FEATURES 0
+struct aio_ring {
+ unsigned id; /* kernel internal index number */
+ unsigned nr; /* number of io_events */
+ unsigned head;
+ unsigned tail;
+
+ unsigned magic;
+ unsigned compat_features;
+ unsigned incompat_features;
+ unsigned header_length; /* size of aio_ring */
+
+
+ struct io_event io_events[0];
+}; /* 128 bytes + ring size */
+
+#define AIO_RING_PAGES 8
+
+struct kioctx {
+ atomic_t users;
+ atomic_t dead;
+
+ /* This needs improving */
+ unsigned long user_id;
+ struct hlist_node list;
+
+ /*
+ * This is what userspace passed to io_setup(), it's not used for
+ * anything but counting against the global max_reqs quota.
+ *
+ * The real limit is nr_events - 1, which will be larger (see
+ * aio_setup_ring())
+ */
+ unsigned max_reqs;
+
+ /* Size of ringbuffer, in units of struct io_event */
+ unsigned nr_events;
+
+ unsigned long mmap_base;
+ unsigned long mmap_size;
+
+ struct page **ring_pages;
+ long nr_pages;
+
+ struct rcu_head rcu_head;
+ struct work_struct rcu_work;
+
+ struct {
+ atomic_t reqs_active;
+ } ____cacheline_aligned_in_smp;
+
+ struct {
+ spinlock_t ctx_lock;
+ struct list_head active_reqs; /* used for cancellation */
+ } ____cacheline_aligned_in_smp;
+
+ struct {
+ struct mutex ring_lock;
+ wait_queue_head_t wait;
+ } ____cacheline_aligned_in_smp;
+
+ struct {
+ unsigned tail;
+ spinlock_t completion_lock;
+ } ____cacheline_aligned_in_smp;
+
+ struct page *internal_pages[AIO_RING_PAGES];
+};
/*------ sysctl variables----*/
static DEFINE_SPINLOCK(aio_nr_lock);
static struct kmem_cache *kiocb_cachep;
static struct kmem_cache *kioctx_cachep;
-static struct workqueue_struct *aio_wq;
-
-/* Used for rare fput completion. */
-static void aio_fput_routine(struct work_struct *);
-static DECLARE_WORK(fput_work, aio_fput_routine);
-
-static DEFINE_SPINLOCK(fput_lock);
-static LIST_HEAD(fput_head);
-
-static void aio_kick_handler(struct work_struct *);
-static void aio_queue_work(struct kioctx *);
-
/* aio_setup
* Creates the slab caches used by the aio routines, panic on
* failure as this is done early during the boot sequence.
kiocb_cachep = KMEM_CACHE(kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
- aio_wq = create_workqueue("aio");
-
- pr_debug("aio_setup: sizeof(struct page) = %d\n", (int)sizeof(struct page));
+ pr_debug("sizeof(struct page) = %zu\n", sizeof(struct page));
return 0;
}
+__initcall(aio_setup);
static void aio_free_ring(struct kioctx *ctx)
{
- struct aio_ring_info *info = &ctx->ring_info;
long i;
- for (i=0; i<info->nr_pages; i++)
- put_page(info->ring_pages[i]);
+ for (i = 0; i < ctx->nr_pages; i++)
+ put_page(ctx->ring_pages[i]);
- if (info->mmap_size) {
- down_write(&ctx->mm->mmap_sem);
- do_munmap(ctx->mm, info->mmap_base, info->mmap_size);
- up_write(&ctx->mm->mmap_sem);
- }
-
- if (info->ring_pages && info->ring_pages != info->internal_pages)
- kfree(info->ring_pages);
- info->ring_pages = NULL;
- info->nr = 0;
+ if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages)
+ kfree(ctx->ring_pages);
}
static int aio_setup_ring(struct kioctx *ctx)
{
struct aio_ring *ring;
- struct aio_ring_info *info = &ctx->ring_info;
unsigned nr_events = ctx->max_reqs;
- unsigned long size;
+ struct mm_struct *mm = current->mm;
+ unsigned long size, populate;
int nr_pages;
/* Compensate for the ring buffer's head/tail overlap entry */
nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring)) / sizeof(struct io_event);
- info->nr = 0;
- info->ring_pages = info->internal_pages;
+ ctx->nr_events = 0;
+ ctx->ring_pages = ctx->internal_pages;
if (nr_pages > AIO_RING_PAGES) {
- info->ring_pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
- if (!info->ring_pages)
+ ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *),
+ GFP_KERNEL);
+ if (!ctx->ring_pages)
return -ENOMEM;
}
- info->mmap_size = nr_pages * PAGE_SIZE;
- dprintk("attempting mmap of %lu bytes\n", info->mmap_size);
- down_write(&ctx->mm->mmap_sem);
- info->mmap_base = do_mmap(NULL, 0, info->mmap_size,
- PROT_READ|PROT_WRITE, MAP_ANONYMOUS|MAP_PRIVATE,
- 0);
- if (IS_ERR((void *)info->mmap_base)) {
- up_write(&ctx->mm->mmap_sem);
- info->mmap_size = 0;
+ ctx->mmap_size = nr_pages * PAGE_SIZE;
+ pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size);
+ down_write(&mm->mmap_sem);
+ ctx->mmap_base = do_mmap_pgoff(NULL, 0, ctx->mmap_size,
+ PROT_READ|PROT_WRITE,
+ MAP_ANONYMOUS|MAP_PRIVATE, 0, &populate);
+ if (IS_ERR((void *)ctx->mmap_base)) {
+ up_write(&mm->mmap_sem);
+ ctx->mmap_size = 0;
aio_free_ring(ctx);
return -EAGAIN;
}
- dprintk("mmap address: 0x%08lx\n", info->mmap_base);
- info->nr_pages = get_user_pages(current, ctx->mm,
- info->mmap_base, nr_pages,
- 1, 0, info->ring_pages, NULL);
- up_write(&ctx->mm->mmap_sem);
+ pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base);
+ ctx->nr_pages = get_user_pages(current, mm, ctx->mmap_base, nr_pages,
+ 1, 0, ctx->ring_pages, NULL);
+ up_write(&mm->mmap_sem);
- if (unlikely(info->nr_pages != nr_pages)) {
+ if (unlikely(ctx->nr_pages != nr_pages)) {
aio_free_ring(ctx);
return -EAGAIN;
}
+ if (populate)
+ mm_populate(ctx->mmap_base, populate);
- ctx->user_id = info->mmap_base;
+ ctx->user_id = ctx->mmap_base;
+ ctx->nr_events = nr_events; /* trusted copy */
- info->nr = nr_events; /* trusted copy */
-
- ring = kmap_atomic(info->ring_pages[0], KM_USER0);
+ ring = kmap_atomic(ctx->ring_pages[0]);
ring->nr = nr_events; /* user copy */
ring->id = ctx->user_id;
ring->head = ring->tail = 0;
ring->compat_features = AIO_RING_COMPAT_FEATURES;
ring->incompat_features = AIO_RING_INCOMPAT_FEATURES;
ring->header_length = sizeof(struct aio_ring);
- kunmap_atomic(ring, KM_USER0);
+ kunmap_atomic(ring);
+ flush_dcache_page(ctx->ring_pages[0]);
return 0;
}
-
-/* aio_ring_event: returns a pointer to the event at the given index from
- * kmap_atomic(, km). Release the pointer with put_aio_ring_event();
- */
#define AIO_EVENTS_PER_PAGE (PAGE_SIZE / sizeof(struct io_event))
#define AIO_EVENTS_FIRST_PAGE ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event))
#define AIO_EVENTS_OFFSET (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE)
-#define aio_ring_event(info, nr, km) ({ \
- unsigned pos = (nr) + AIO_EVENTS_OFFSET; \
- struct io_event *__event; \
- __event = kmap_atomic( \
- (info)->ring_pages[pos / AIO_EVENTS_PER_PAGE], km); \
- __event += pos % AIO_EVENTS_PER_PAGE; \
- __event; \
-})
-
-#define put_aio_ring_event(event, km) do { \
- struct io_event *__event = (event); \
- (void)__event; \
- kunmap_atomic((void *)((unsigned long)__event & PAGE_MASK), km); \
-} while(0)
+void kiocb_set_cancel_fn(struct kiocb *req, kiocb_cancel_fn *cancel)
+{
+ struct kioctx *ctx = req->ki_ctx;
+ unsigned long flags;
+
+ spin_lock_irqsave(&ctx->ctx_lock, flags);
+
+ if (!req->ki_list.next)
+ list_add(&req->ki_list, &ctx->active_reqs);
+
+ req->ki_cancel = cancel;
+
+ spin_unlock_irqrestore(&ctx->ctx_lock, flags);
+}
+EXPORT_SYMBOL(kiocb_set_cancel_fn);
+
+static int kiocb_cancel(struct kioctx *ctx, struct kiocb *kiocb,
+ struct io_event *res)
+{
+ kiocb_cancel_fn *old, *cancel;
+ int ret = -EINVAL;
+
+ /*
+ * Don't want to set kiocb->ki_cancel = KIOCB_CANCELLED unless it
+ * actually has a cancel function, hence the cmpxchg()
+ */
+
+ cancel = ACCESS_ONCE(kiocb->ki_cancel);
+ do {
+ if (!cancel || cancel == KIOCB_CANCELLED)
+ return ret;
+
+ old = cancel;
+ cancel = cmpxchg(&kiocb->ki_cancel, old, KIOCB_CANCELLED);
+ } while (cancel != old);
+
+ atomic_inc(&kiocb->ki_users);
+ spin_unlock_irq(&ctx->ctx_lock);
+
+ memset(res, 0, sizeof(*res));
+ res->obj = (u64)(unsigned long)kiocb->ki_obj.user;
+ res->data = kiocb->ki_user_data;
+ ret = cancel(kiocb, res);
+
+ spin_lock_irq(&ctx->ctx_lock);
+
+ return ret;
+}
+
+static void free_ioctx_rcu(struct rcu_head *head)
+{
+ struct kioctx *ctx = container_of(head, struct kioctx, rcu_head);
+ kmem_cache_free(kioctx_cachep, ctx);
+}
+
+/*
+ * When this function runs, the kioctx has been removed from the "hash table"
+ * and ctx->users has dropped to 0, so we know no more kiocbs can be submitted -
+ * now it's safe to cancel any that need to be.
+ */
+static void free_ioctx(struct kioctx *ctx)
+{
+ struct aio_ring *ring;
+ struct io_event res;
+ struct kiocb *req;
+ unsigned head, avail;
+
+ spin_lock_irq(&ctx->ctx_lock);
+
+ while (!list_empty(&ctx->active_reqs)) {
+ req = list_first_entry(&ctx->active_reqs,
+ struct kiocb, ki_list);
+
+ list_del_init(&req->ki_list);
+ kiocb_cancel(ctx, req, &res);
+ }
+
+ spin_unlock_irq(&ctx->ctx_lock);
+
+ ring = kmap_atomic(ctx->ring_pages[0]);
+ head = ring->head;
+ kunmap_atomic(ring);
+
+ while (atomic_read(&ctx->reqs_active) > 0) {
+ wait_event(ctx->wait,
+ head != ctx->tail ||
+ atomic_read(&ctx->reqs_active) <= 0);
+
+ avail = (head <= ctx->tail ? ctx->tail : ctx->nr_events) - head;
+
+ atomic_sub(avail, &ctx->reqs_active);
+ head += avail;
+ head %= ctx->nr_events;
+ }
+
+ WARN_ON(atomic_read(&ctx->reqs_active) < 0);
+
+ aio_free_ring(ctx);
+
+ pr_debug("freeing %p\n", ctx);
+
+ /*
+ * Here the call_rcu() is between the wait_event() for reqs_active to
+ * hit 0, and freeing the ioctx.
+ *
+ * aio_complete() decrements reqs_active, but it has to touch the ioctx
+ * after to issue a wakeup so we use rcu.
+ */
+ call_rcu(&ctx->rcu_head, free_ioctx_rcu);
+}
+
+static void put_ioctx(struct kioctx *ctx)
+{
+ if (unlikely(atomic_dec_and_test(&ctx->users)))
+ free_ioctx(ctx);
+}
/* ioctx_alloc
* Allocates and initializes an ioctx. Returns an ERR_PTR if it failed.
*/
static struct kioctx *ioctx_alloc(unsigned nr_events)
{
- struct mm_struct *mm;
+ struct mm_struct *mm = current->mm;
struct kioctx *ctx;
+ int err = -ENOMEM;
/* Prevent overflows */
if ((nr_events > (0x10000000U / sizeof(struct io_event))) ||
return ERR_PTR(-EINVAL);
}
- if ((unsigned long)nr_events > aio_max_nr)
+ if (!nr_events || (unsigned long)nr_events > aio_max_nr)
return ERR_PTR(-EAGAIN);
ctx = kmem_cache_zalloc(kioctx_cachep, GFP_KERNEL);
return ERR_PTR(-ENOMEM);
ctx->max_reqs = nr_events;
- mm = ctx->mm = current->mm;
- atomic_inc(&mm->mm_count);
- atomic_set(&ctx->users, 1);
+ atomic_set(&ctx->users, 2);
+ atomic_set(&ctx->dead, 0);
spin_lock_init(&ctx->ctx_lock);
- spin_lock_init(&ctx->ring_info.ring_lock);
+ spin_lock_init(&ctx->completion_lock);
+ mutex_init(&ctx->ring_lock);
init_waitqueue_head(&ctx->wait);
INIT_LIST_HEAD(&ctx->active_reqs);
- INIT_LIST_HEAD(&ctx->run_list);
- INIT_DELAYED_WORK(&ctx->wq, aio_kick_handler);
if (aio_setup_ring(ctx) < 0)
goto out_freectx;
/* limit the number of system wide aios */
spin_lock(&aio_nr_lock);
- if (aio_nr + ctx->max_reqs > aio_max_nr ||
- aio_nr + ctx->max_reqs < aio_nr)
- ctx->max_reqs = 0;
- else
- aio_nr += ctx->max_reqs;
- spin_unlock(&aio_nr_lock);
- if (ctx->max_reqs == 0)
+ if (aio_nr + nr_events > aio_max_nr ||
+ aio_nr + nr_events < aio_nr) {
+ spin_unlock(&aio_nr_lock);
goto out_cleanup;
+ }
+ aio_nr += ctx->max_reqs;
+ spin_unlock(&aio_nr_lock);
- /* now link into global list. kludge. FIXME */
- write_lock(&mm->ioctx_list_lock);
- ctx->next = mm->ioctx_list;
- mm->ioctx_list = ctx;
- write_unlock(&mm->ioctx_list_lock);
+ /* now link into global list. */
+ spin_lock(&mm->ioctx_lock);
+ hlist_add_head_rcu(&ctx->list, &mm->ioctx_list);
+ spin_unlock(&mm->ioctx_lock);
- dprintk("aio: allocated ioctx %p[%ld]: mm=%p mask=0x%x\n",
- ctx, ctx->user_id, current->mm, ctx->ring_info.nr);
+ pr_debug("allocated ioctx %p[%ld]: mm=%p mask=0x%x\n",
+ ctx, ctx->user_id, mm, ctx->nr_events);
return ctx;
out_cleanup:
- __put_ioctx(ctx);
- return ERR_PTR(-EAGAIN);
-
+ err = -EAGAIN;
+ aio_free_ring(ctx);
out_freectx:
- mmdrop(mm);
kmem_cache_free(kioctx_cachep, ctx);
- ctx = ERR_PTR(-ENOMEM);
+ pr_debug("error allocating ioctx %d\n", err);
+ return ERR_PTR(err);
+}
- dprintk("aio: error allocating ioctx %p\n", ctx);
- return ctx;
+static void kill_ioctx_work(struct work_struct *work)
+{
+ struct kioctx *ctx = container_of(work, struct kioctx, rcu_work);
+
+ wake_up_all(&ctx->wait);
+ put_ioctx(ctx);
}
-/* aio_cancel_all
- * Cancels all outstanding aio requests on an aio context. Used
- * when the processes owning a context have all exited to encourage
- * the rapid destruction of the kioctx.
- */
-static void aio_cancel_all(struct kioctx *ctx)
+static void kill_ioctx_rcu(struct rcu_head *head)
{
- int (*cancel)(struct kiocb *, struct io_event *);
- struct io_event res;
- spin_lock_irq(&ctx->ctx_lock);
- ctx->dead = 1;
- while (!list_empty(&ctx->active_reqs)) {
- struct list_head *pos = ctx->active_reqs.next;
- struct kiocb *iocb = list_kiocb(pos);
- list_del_init(&iocb->ki_list);
- cancel = iocb->ki_cancel;
- kiocbSetCancelled(iocb);
- if (cancel) {
- iocb->ki_users++;
- spin_unlock_irq(&ctx->ctx_lock);
- cancel(iocb, &res);
- spin_lock_irq(&ctx->ctx_lock);
- }
- }
- spin_unlock_irq(&ctx->ctx_lock);
+ struct kioctx *ctx = container_of(head, struct kioctx, rcu_head);
+
+ INIT_WORK(&ctx->rcu_work, kill_ioctx_work);
+ schedule_work(&ctx->rcu_work);
}
-static void wait_for_all_aios(struct kioctx *ctx)
+/* kill_ioctx
+ * Cancels all outstanding aio requests on an aio context. Used
+ * when the processes owning a context have all exited to encourage
+ * the rapid destruction of the kioctx.
+ */
+static void kill_ioctx(struct mm_struct *mm, struct kioctx *ctx)
{
- struct task_struct *tsk = current;
- DECLARE_WAITQUEUE(wait, tsk);
+ if (!atomic_xchg(&ctx->dead, 1)) {
+ spin_lock(&mm->ioctx_lock);
+ hlist_del_rcu(&ctx->list);
+ spin_unlock(&mm->ioctx_lock);
- spin_lock_irq(&ctx->ctx_lock);
- if (!ctx->reqs_active)
- goto out;
+ /*
+ * It'd be more correct to do this in free_ioctx(), after all
+ * the outstanding kiocbs have finished - but by then io_destroy
+ * has already returned, so io_setup() could potentially return
+ * -EAGAIN with no ioctxs actually in use (as far as userspace
+ * could tell).
+ */
+ spin_lock(&aio_nr_lock);
+ BUG_ON(aio_nr - ctx->max_reqs > aio_nr);
+ aio_nr -= ctx->max_reqs;
+ spin_unlock(&aio_nr_lock);
- add_wait_queue(&ctx->wait, &wait);
- set_task_state(tsk, TASK_UNINTERRUPTIBLE);
- while (ctx->reqs_active) {
- spin_unlock_irq(&ctx->ctx_lock);
- io_schedule();
- set_task_state(tsk, TASK_UNINTERRUPTIBLE);
- spin_lock_irq(&ctx->ctx_lock);
- }
- __set_task_state(tsk, TASK_RUNNING);
- remove_wait_queue(&ctx->wait, &wait);
+ if (ctx->mmap_size)
+ vm_munmap(ctx->mmap_base, ctx->mmap_size);
-out:
- spin_unlock_irq(&ctx->ctx_lock);
+ /* Between hlist_del_rcu() and dropping the initial ref */
+ call_rcu(&ctx->rcu_head, kill_ioctx_rcu);
+ }
}
/* wait_on_sync_kiocb:
*/
ssize_t wait_on_sync_kiocb(struct kiocb *iocb)
{
- while (iocb->ki_users) {
+ while (atomic_read(&iocb->ki_users)) {
set_current_state(TASK_UNINTERRUPTIBLE);
- if (!iocb->ki_users)
+ if (!atomic_read(&iocb->ki_users))
break;
io_schedule();
}
__set_current_state(TASK_RUNNING);
return iocb->ki_user_data;
}
+EXPORT_SYMBOL(wait_on_sync_kiocb);
-/* exit_aio: called when the last user of mm goes away. At this point,
- * there is no way for any new requests to be submited or any of the
- * io_* syscalls to be called on the context. However, there may be
- * outstanding requests which hold references to the context; as they
- * go away, they will call put_ioctx and release any pinned memory
- * associated with the request (held via struct page * references).
+/*
+ * exit_aio: called when the last user of mm goes away. At this point, there is
+ * no way for any new requests to be submited or any of the io_* syscalls to be
+ * called on the context.
+ *
+ * There may be outstanding kiocbs, but free_ioctx() will explicitly wait on
+ * them.
*/
void exit_aio(struct mm_struct *mm)
{
- struct kioctx *ctx = mm->ioctx_list;
- mm->ioctx_list = NULL;
- while (ctx) {
- struct kioctx *next = ctx->next;
- ctx->next = NULL;
- aio_cancel_all(ctx);
-
- wait_for_all_aios(ctx);
- /*
- * Ensure we don't leave the ctx on the aio_wq
- */
- cancel_work_sync(&ctx->wq.work);
+ struct kioctx *ctx;
+ struct hlist_node *n;
+ hlist_for_each_entry_safe(ctx, n, &mm->ioctx_list, list) {
if (1 != atomic_read(&ctx->users))
printk(KERN_DEBUG
"exit_aio:ioctx still alive: %d %d %d\n",
- atomic_read(&ctx->users), ctx->dead,
- ctx->reqs_active);
- put_ioctx(ctx);
- ctx = next;
- }
-}
-
-/* __put_ioctx
- * Called when the last user of an aio context has gone away,
- * and the struct needs to be freed.
- */
-void __put_ioctx(struct kioctx *ctx)
-{
- unsigned nr_events = ctx->max_reqs;
-
- BUG_ON(ctx->reqs_active);
-
- cancel_delayed_work(&ctx->wq);
- cancel_work_sync(&ctx->wq.work);
- aio_free_ring(ctx);
- mmdrop(ctx->mm);
- ctx->mm = NULL;
- pr_debug("__put_ioctx: freeing %p\n", ctx);
- kmem_cache_free(kioctx_cachep, ctx);
+ atomic_read(&ctx->users),
+ atomic_read(&ctx->dead),
+ atomic_read(&ctx->reqs_active));
+ /*
+ * We don't need to bother with munmap() here -
+ * exit_mmap(mm) is coming and it'll unmap everything.
+ * Since aio_free_ring() uses non-zero ->mmap_size
+ * as indicator that it needs to unmap the area,
+ * just set it to 0; aio_free_ring() is the only
+ * place that uses ->mmap_size, so it's safe.
+ */
+ ctx->mmap_size = 0;
- if (nr_events) {
- spin_lock(&aio_nr_lock);
- BUG_ON(aio_nr - nr_events > aio_nr);
- aio_nr -= nr_events;
- spin_unlock(&aio_nr_lock);
+ kill_ioctx(mm, ctx);
}
}
/* aio_get_req
- * Allocate a slot for an aio request. Increments the users count
+ * Allocate a slot for an aio request. Increments the ki_users count
* of the kioctx so that the kioctx stays around until all requests are
* complete. Returns NULL if no requests are free.
*
- * Returns with kiocb->users set to 2. The io submit code path holds
+ * Returns with kiocb->ki_users set to 2. The io submit code path holds
* an extra reference while submitting the i/o.
* This prevents races between the aio code path referencing the
* req (after submitting it) and aio_complete() freeing the req.
*/
-static struct kiocb *__aio_get_req(struct kioctx *ctx)
+static inline struct kiocb *aio_get_req(struct kioctx *ctx)
{
- struct kiocb *req = NULL;
- struct aio_ring *ring;
- int okay = 0;
+ struct kiocb *req;
- req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL);
- if (unlikely(!req))
+ if (atomic_read(&ctx->reqs_active) >= ctx->nr_events)
return NULL;
- req->ki_flags = 0;
- req->ki_users = 2;
- req->ki_key = 0;
- req->ki_ctx = ctx;
- req->ki_cancel = NULL;
- req->ki_retry = NULL;
- req->ki_dtor = NULL;
- req->private = NULL;
- req->ki_iovec = NULL;
- INIT_LIST_HEAD(&req->ki_run_list);
- req->ki_eventfd = ERR_PTR(-EINVAL);
-
- /* Check if the completion queue has enough free space to
- * accept an event from this io.
- */
- spin_lock_irq(&ctx->ctx_lock);
- ring = kmap_atomic(ctx->ring_info.ring_pages[0], KM_USER0);
- if (ctx->reqs_active < aio_ring_avail(&ctx->ring_info, ring)) {
- list_add(&req->ki_list, &ctx->active_reqs);
- ctx->reqs_active++;
- okay = 1;
- }
- kunmap_atomic(ring, KM_USER0);
- spin_unlock_irq(&ctx->ctx_lock);
+ if (atomic_inc_return(&ctx->reqs_active) > ctx->nr_events - 1)
+ goto out_put;
- if (!okay) {
- kmem_cache_free(kiocb_cachep, req);
- req = NULL;
- }
+ req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
+ if (unlikely(!req))
+ goto out_put;
- return req;
-}
+ atomic_set(&req->ki_users, 2);
+ req->ki_ctx = ctx;
-static inline struct kiocb *aio_get_req(struct kioctx *ctx)
-{
- struct kiocb *req;
- /* Handle a potential starvation case -- should be exceedingly rare as
- * requests will be stuck on fput_head only if the aio_fput_routine is
- * delayed and the requests were the last user of the struct file.
- */
- req = __aio_get_req(ctx);
- if (unlikely(NULL == req)) {
- aio_fput_routine(NULL);
- req = __aio_get_req(ctx);
- }
return req;
+out_put:
+ atomic_dec(&ctx->reqs_active);
+ return NULL;
}
-static inline void really_put_req(struct kioctx *ctx, struct kiocb *req)
+static void kiocb_free(struct kiocb *req)
{
- assert_spin_locked(&ctx->ctx_lock);
-
- if (!IS_ERR(req->ki_eventfd))
- fput(req->ki_eventfd);
+ if (req->ki_filp)
+ fput(req->ki_filp);
+ if (req->ki_eventfd != NULL)
+ eventfd_ctx_put(req->ki_eventfd);
if (req->ki_dtor)
req->ki_dtor(req);
if (req->ki_iovec != &req->ki_inline_vec)
- kfree(req->ki_iovec);
- kmem_cache_free(kiocb_cachep, req);
- ctx->reqs_active--;
-
- if (unlikely(!ctx->reqs_active && ctx->dead))
- wake_up(&ctx->wait);
-}
-
-static void aio_fput_routine(struct work_struct *data)
-{
- spin_lock_irq(&fput_lock);
- while (likely(!list_empty(&fput_head))) {
- struct kiocb *req = list_kiocb(fput_head.next);
- struct kioctx *ctx = req->ki_ctx;
-
- list_del(&req->ki_list);
- spin_unlock_irq(&fput_lock);
-
- /* Complete the fput */
- __fput(req->ki_filp);
-
- /* Link the iocb into the context's free list */
- spin_lock_irq(&ctx->ctx_lock);
- really_put_req(ctx, req);
- spin_unlock_irq(&ctx->ctx_lock);
-
- put_ioctx(ctx);
- spin_lock_irq(&fput_lock);
- }
- spin_unlock_irq(&fput_lock);
-}
-
-/* __aio_put_req
- * Returns true if this put was the last user of the request.
- */
-static int __aio_put_req(struct kioctx *ctx, struct kiocb *req)
-{
- dprintk(KERN_DEBUG "aio_put(%p): f_count=%d\n",
- req, atomic_read(&req->ki_filp->f_count));
-
- assert_spin_locked(&ctx->ctx_lock);
-
- req->ki_users --;
- BUG_ON(req->ki_users < 0);
- if (likely(req->ki_users))
- return 0;
- list_del(&req->ki_list); /* remove from active_reqs */
- req->ki_cancel = NULL;
- req->ki_retry = NULL;
-
- /* Must be done under the lock to serialise against cancellation.
- * Call this aio_fput as it duplicates fput via the fput_work.
- */
- if (unlikely(atomic_dec_and_test(&req->ki_filp->f_count))) {
- get_ioctx(ctx);
- spin_lock(&fput_lock);
- list_add(&req->ki_list, &fput_head);
- spin_unlock(&fput_lock);
- queue_work(aio_wq, &fput_work);
- } else
- really_put_req(ctx, req);
- return 1;
-}
-
-/* aio_put_req
- * Returns true if this put was the last user of the kiocb,
- * false if the request is still in use.
- */
-int aio_put_req(struct kiocb *req)
-{
- struct kioctx *ctx = req->ki_ctx;
- int ret;
- spin_lock_irq(&ctx->ctx_lock);
- ret = __aio_put_req(ctx, req);
- spin_unlock_irq(&ctx->ctx_lock);
- return ret;
-}
-
-/* Lookup an ioctx id. ioctx_list is lockless for reads.
- * FIXME: this is O(n) and is only suitable for development.
- */
-struct kioctx *lookup_ioctx(unsigned long ctx_id)
-{
- struct kioctx *ioctx;
- struct mm_struct *mm;
-
- mm = current->mm;
- read_lock(&mm->ioctx_list_lock);
- for (ioctx = mm->ioctx_list; ioctx; ioctx = ioctx->next)
- if (likely(ioctx->user_id == ctx_id && !ioctx->dead)) {
- get_ioctx(ioctx);
- break;
- }
- read_unlock(&mm->ioctx_list_lock);
-
- return ioctx;
-}
-
-/*
- * use_mm
- * Makes the calling kernel thread take on the specified
- * mm context.
- * Called by the retry thread execute retries within the
- * iocb issuer's mm context, so that copy_from/to_user
- * operations work seamlessly for aio.
- * (Note: this routine is intended to be called only
- * from a kernel thread context)
- */
-static void use_mm(struct mm_struct *mm)
-{
- struct mm_struct *active_mm;
- struct task_struct *tsk = current;
-
- task_lock(tsk);
- tsk->flags |= PF_BORROWED_MM;
- active_mm = tsk->active_mm;
- atomic_inc(&mm->mm_count);
- tsk->mm = mm;
- tsk->active_mm = mm;
- /*
- * Note that on UML this *requires* PF_BORROWED_MM to be set, otherwise
- * it won't work. Update it accordingly if you change it here
- */
- switch_mm(active_mm, mm, tsk);
- task_unlock(tsk);
-
- mmdrop(active_mm);
-}
-
-/*
- * unuse_mm
- * Reverses the effect of use_mm, i.e. releases the
- * specified mm context which was earlier taken on
- * by the calling kernel thread
- * (Note: this routine is intended to be called only
- * from a kernel thread context)
- */
-static void unuse_mm(struct mm_struct *mm)
-{
- struct task_struct *tsk = current;
-
- task_lock(tsk);
- tsk->flags &= ~PF_BORROWED_MM;
- tsk->mm = NULL;
- /* active_mm is still 'mm' */
- enter_lazy_tlb(mm, tsk);
- task_unlock(tsk);
-}
-
-/*
- * Queue up a kiocb to be retried. Assumes that the kiocb
- * has already been marked as kicked, and places it on
- * the retry run list for the corresponding ioctx, if it
- * isn't already queued. Returns 1 if it actually queued
- * the kiocb (to tell the caller to activate the work
- * queue to process it), or 0, if it found that it was
- * already queued.
- */
-static inline int __queue_kicked_iocb(struct kiocb *iocb)
-{
- struct kioctx *ctx = iocb->ki_ctx;
-
- assert_spin_locked(&ctx->ctx_lock);
-
- if (list_empty(&iocb->ki_run_list)) {
- list_add_tail(&iocb->ki_run_list,
- &ctx->run_list);
- return 1;
- }
- return 0;
-}
-
-/* aio_run_iocb
- * This is the core aio execution routine. It is
- * invoked both for initial i/o submission and
- * subsequent retries via the aio_kick_handler.
- * Expects to be invoked with iocb->ki_ctx->lock
- * already held. The lock is released and reacquired
- * as needed during processing.
- *
- * Calls the iocb retry method (already setup for the
- * iocb on initial submission) for operation specific
- * handling, but takes care of most of common retry
- * execution details for a given iocb. The retry method
- * needs to be non-blocking as far as possible, to avoid
- * holding up other iocbs waiting to be serviced by the
- * retry kernel thread.
- *
- * The trickier parts in this code have to do with
- * ensuring that only one retry instance is in progress
- * for a given iocb at any time. Providing that guarantee
- * simplifies the coding of individual aio operations as
- * it avoids various potential races.
- */
-static ssize_t aio_run_iocb(struct kiocb *iocb)
-{
- struct kioctx *ctx = iocb->ki_ctx;
- ssize_t (*retry)(struct kiocb *);
- ssize_t ret;
-
- if (!(retry = iocb->ki_retry)) {
- printk("aio_run_iocb: iocb->ki_retry = NULL\n");
- return 0;
- }
-
- /*
- * We don't want the next retry iteration for this
- * operation to start until this one has returned and
- * updated the iocb state. However, wait_queue functions
- * can trigger a kick_iocb from interrupt context in the
- * meantime, indicating that data is available for the next
- * iteration. We want to remember that and enable the
- * next retry iteration _after_ we are through with
- * this one.
- *
- * So, in order to be able to register a "kick", but
- * prevent it from being queued now, we clear the kick
- * flag, but make the kick code *think* that the iocb is
- * still on the run list until we are actually done.
- * When we are done with this iteration, we check if
- * the iocb was kicked in the meantime and if so, queue
- * it up afresh.
- */
-
- kiocbClearKicked(iocb);
-
- /*
- * This is so that aio_complete knows it doesn't need to
- * pull the iocb off the run list (We can't just call
- * INIT_LIST_HEAD because we don't want a kick_iocb to
- * queue this on the run list yet)
- */
- iocb->ki_run_list.next = iocb->ki_run_list.prev = NULL;
- spin_unlock_irq(&ctx->ctx_lock);
-
- /* Quit retrying if the i/o has been cancelled */
- if (kiocbIsCancelled(iocb)) {
- ret = -EINTR;
- aio_complete(iocb, ret, 0);
- /* must not access the iocb after this */
- goto out;
- }
-
- /*
- * Now we are all set to call the retry method in async
- * context.
- */
- ret = retry(iocb);
-
- if (ret != -EIOCBRETRY && ret != -EIOCBQUEUED) {
- BUG_ON(!list_empty(&iocb->ki_wait.task_list));
- aio_complete(iocb, ret, 0);
- }
-out:
- spin_lock_irq(&ctx->ctx_lock);
-
- if (-EIOCBRETRY == ret) {
- /*
- * OK, now that we are done with this iteration
- * and know that there is more left to go,
- * this is where we let go so that a subsequent
- * "kick" can start the next iteration
- */
-
- /* will make __queue_kicked_iocb succeed from here on */
- INIT_LIST_HEAD(&iocb->ki_run_list);
- /* we must queue the next iteration ourselves, if it
- * has already been kicked */
- if (kiocbIsKicked(iocb)) {
- __queue_kicked_iocb(iocb);
-
- /*
- * __queue_kicked_iocb will always return 1 here, because
- * iocb->ki_run_list is empty at this point so it should
- * be safe to unconditionally queue the context into the
- * work queue.
- */
- aio_queue_work(ctx);
- }
- }
- return ret;
-}
-
-/*
- * __aio_run_iocbs:
- * Process all pending retries queued on the ioctx
- * run list.
- * Assumes it is operating within the aio issuer's mm
- * context.
- */
-static int __aio_run_iocbs(struct kioctx *ctx)
-{
- struct kiocb *iocb;
- struct list_head run_list;
-
- assert_spin_locked(&ctx->ctx_lock);
-
- list_replace_init(&ctx->run_list, &run_list);
- while (!list_empty(&run_list)) {
- iocb = list_entry(run_list.next, struct kiocb,
- ki_run_list);
- list_del(&iocb->ki_run_list);
- /*
- * Hold an extra reference while retrying i/o.
- */
- iocb->ki_users++; /* grab extra reference */
- aio_run_iocb(iocb);
- __aio_put_req(ctx, iocb);
- }
- if (!list_empty(&ctx->run_list))
- return 1;
- return 0;
-}
-
-static void aio_queue_work(struct kioctx * ctx)
-{
- unsigned long timeout;
- /*
- * if someone is waiting, get the work started right
- * away, otherwise, use a longer delay
- */
- smp_mb();
- if (waitqueue_active(&ctx->wait))
- timeout = 1;
- else
- timeout = HZ/10;
- queue_delayed_work(aio_wq, &ctx->wq, timeout);
-}
-
-
-/*
- * aio_run_iocbs:
- * Process all pending retries queued on the ioctx
- * run list.
- * Assumes it is operating within the aio issuer's mm
- * context.
- */
-static inline void aio_run_iocbs(struct kioctx *ctx)
-{
- int requeue;
-
- spin_lock_irq(&ctx->ctx_lock);
-
- requeue = __aio_run_iocbs(ctx);
- spin_unlock_irq(&ctx->ctx_lock);
- if (requeue)
- aio_queue_work(ctx);
-}
-
-/*
- * just like aio_run_iocbs, but keeps running them until
- * the list stays empty
- */
-static inline void aio_run_all_iocbs(struct kioctx *ctx)
-{
- spin_lock_irq(&ctx->ctx_lock);
- while (__aio_run_iocbs(ctx))
- ;
- spin_unlock_irq(&ctx->ctx_lock);
-}
-
-/*
- * aio_kick_handler:
- * Work queue handler triggered to process pending
- * retries on an ioctx. Takes on the aio issuer's
- * mm context before running the iocbs, so that
- * copy_xxx_user operates on the issuer's address
- * space.
- * Run on aiod's context.
- */
-static void aio_kick_handler(struct work_struct *work)
-{
- struct kioctx *ctx = container_of(work, struct kioctx, wq.work);
- mm_segment_t oldfs = get_fs();
- struct mm_struct *mm;
- int requeue;
-
- set_fs(USER_DS);
- use_mm(ctx->mm);
- spin_lock_irq(&ctx->ctx_lock);
- requeue =__aio_run_iocbs(ctx);
- mm = ctx->mm;
- spin_unlock_irq(&ctx->ctx_lock);
- unuse_mm(mm);
- set_fs(oldfs);
- /*
- * we're in a worker thread already, don't use queue_delayed_work,
- */
- if (requeue)
- queue_delayed_work(aio_wq, &ctx->wq, 0);
-}
-
-
-/*
- * Called by kick_iocb to queue the kiocb for retry
- * and if required activate the aio work queue to process
- * it
- */
-static void try_queue_kicked_iocb(struct kiocb *iocb)
-{
- struct kioctx *ctx = iocb->ki_ctx;
- unsigned long flags;
- int run = 0;
-
- /* We're supposed to be the only path putting the iocb back on the run
- * list. If we find that the iocb is *back* on a wait queue already
- * than retry has happened before we could queue the iocb. This also
- * means that the retry could have completed and freed our iocb, no
- * good. */
- BUG_ON((!list_empty(&iocb->ki_wait.task_list)));
+ kfree(req->ki_iovec);
+ kmem_cache_free(kiocb_cachep, req);
+}
- spin_lock_irqsave(&ctx->ctx_lock, flags);
- /* set this inside the lock so that we can't race with aio_run_iocb()
- * testing it and putting the iocb on the run list under the lock */
- if (!kiocbTryKick(iocb))
- run = __queue_kicked_iocb(iocb);
- spin_unlock_irqrestore(&ctx->ctx_lock, flags);
- if (run)
- aio_queue_work(ctx);
+void aio_put_req(struct kiocb *req)
+{
+ if (atomic_dec_and_test(&req->ki_users))
+ kiocb_free(req);
}
+EXPORT_SYMBOL(aio_put_req);
-/*
- * kick_iocb:
- * Called typically from a wait queue callback context
- * (aio_wake_function) to trigger a retry of the iocb.
- * The retry is usually executed by aio workqueue
- * threads (See aio_kick_handler).
- */
-void kick_iocb(struct kiocb *iocb)
+static struct kioctx *lookup_ioctx(unsigned long ctx_id)
{
- /* sync iocbs are easy: they can only ever be executing from a
- * single context. */
- if (is_sync_kiocb(iocb)) {
- kiocbSetKicked(iocb);
- wake_up_process(iocb->ki_obj.tsk);
- return;
+ struct mm_struct *mm = current->mm;
+ struct kioctx *ctx, *ret = NULL;
+
+ rcu_read_lock();
+
+ hlist_for_each_entry_rcu(ctx, &mm->ioctx_list, list) {
+ if (ctx->user_id == ctx_id) {
+ atomic_inc(&ctx->users);
+ ret = ctx;
+ break;
+ }
}
- try_queue_kicked_iocb(iocb);
+ rcu_read_unlock();
+ return ret;
}
-EXPORT_SYMBOL(kick_iocb);
/* aio_complete
* Called when the io request on the given iocb is complete.
- * Returns true if this is the last user of the request. The
- * only other user of the request can be the cancellation code.
*/
-int aio_complete(struct kiocb *iocb, long res, long res2)
+void aio_complete(struct kiocb *iocb, long res, long res2)
{
struct kioctx *ctx = iocb->ki_ctx;
- struct aio_ring_info *info;
struct aio_ring *ring;
- struct io_event *event;
+ struct io_event *ev_page, *event;
unsigned long flags;
- unsigned long tail;
- int ret;
+ unsigned tail, pos;
/*
* Special case handling for sync iocbs:
* - the sync task helpfully left a reference to itself in the iocb
*/
if (is_sync_kiocb(iocb)) {
- BUG_ON(iocb->ki_users != 1);
+ BUG_ON(atomic_read(&iocb->ki_users) != 1);
iocb->ki_user_data = res;
- iocb->ki_users = 0;
+ atomic_set(&iocb->ki_users, 0);
wake_up_process(iocb->ki_obj.tsk);
- return 1;
+ return;
}
/*
- * Check if the user asked us to deliver the result through an
- * eventfd. The eventfd_signal() function is safe to be called
- * from IRQ context.
+ * Take rcu_read_lock() in case the kioctx is being destroyed, as we
+ * need to issue a wakeup after decrementing reqs_active.
*/
- if (!IS_ERR(iocb->ki_eventfd))
- eventfd_signal(iocb->ki_eventfd, 1);
+ rcu_read_lock();
- info = &ctx->ring_info;
-
- /* add a completion event to the ring buffer.
- * must be done holding ctx->ctx_lock to prevent
- * other code from messing with the tail
- * pointer since we might be called from irq
- * context.
- */
- spin_lock_irqsave(&ctx->ctx_lock, flags);
+ if (iocb->ki_list.next) {
+ unsigned long flags;
- if (iocb->ki_run_list.prev && !list_empty(&iocb->ki_run_list))
- list_del_init(&iocb->ki_run_list);
+ spin_lock_irqsave(&ctx->ctx_lock, flags);
+ list_del(&iocb->ki_list);
+ spin_unlock_irqrestore(&ctx->ctx_lock, flags);
+ }
/*
* cancelled requests don't get events, userland was given one
* when the event got cancelled.
*/
- if (kiocbIsCancelled(iocb))
+ if (unlikely(xchg(&iocb->ki_cancel,
+ KIOCB_CANCELLED) == KIOCB_CANCELLED)) {
+ atomic_dec(&ctx->reqs_active);
+ /* Still need the wake_up in case free_ioctx is waiting */
goto put_rq;
+ }
+
+ /*
+ * Add a completion event to the ring buffer. Must be done holding
+ * ctx->ctx_lock to prevent other code from messing with the tail
+ * pointer since we might be called from irq context.
+ */
+ spin_lock_irqsave(&ctx->completion_lock, flags);
- ring = kmap_atomic(info->ring_pages[0], KM_IRQ1);
+ tail = ctx->tail;
+ pos = tail + AIO_EVENTS_OFFSET;
- tail = info->tail;
- event = aio_ring_event(info, tail, KM_IRQ0);
- if (++tail >= info->nr)
+ if (++tail >= ctx->nr_events)
tail = 0;
+ ev_page = kmap_atomic(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
+ event = ev_page + pos % AIO_EVENTS_PER_PAGE;
+
event->obj = (u64)(unsigned long)iocb->ki_obj.user;
event->data = iocb->ki_user_data;
event->res = res;
event->res2 = res2;
- dprintk("aio_complete: %p[%lu]: %p: %p %Lx %lx %lx\n",
- ctx, tail, iocb, iocb->ki_obj.user, iocb->ki_user_data,
- res, res2);
+ kunmap_atomic(ev_page);
+ flush_dcache_page(ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE]);
+
+ pr_debug("%p[%u]: %p: %p %Lx %lx %lx\n",
+ ctx, tail, iocb, iocb->ki_obj.user, iocb->ki_user_data,
+ res, res2);
/* after flagging the request as done, we
* must never even look at it again
*/
smp_wmb(); /* make event visible before updating tail */
- info->tail = tail;
+ ctx->tail = tail;
+
+ ring = kmap_atomic(ctx->ring_pages[0]);
ring->tail = tail;
+ kunmap_atomic(ring);
+ flush_dcache_page(ctx->ring_pages[0]);
+
+ spin_unlock_irqrestore(&ctx->completion_lock, flags);
- put_aio_ring_event(event, KM_IRQ0);
- kunmap_atomic(ring, KM_IRQ1);
+ pr_debug("added to ring %p at [%u]\n", iocb, tail);
+
+ /*
+ * Check if the user asked us to deliver the result through an
+ * eventfd. The eventfd_signal() function is safe to be called
+ * from IRQ context.
+ */
+ if (iocb->ki_eventfd != NULL)
+ eventfd_signal(iocb->ki_eventfd, 1);
- pr_debug("added to ring %p at [%lu]\n", iocb, tail);
put_rq:
/* everything turned out well, dispose of the aiocb. */
- ret = __aio_put_req(ctx, iocb);
+ aio_put_req(iocb);
+
+ /*
+ * We have to order our ring_info tail store above and test
+ * of the wait list below outside the wait lock. This is
+ * like in wake_up_bit() where clearing a bit has to be
+ * ordered with the unlocked test.
+ */
+ smp_mb();
if (waitqueue_active(&ctx->wait))
wake_up(&ctx->wait);
- spin_unlock_irqrestore(&ctx->ctx_lock, flags);
- return ret;
+ rcu_read_unlock();
}
+EXPORT_SYMBOL(aio_complete);
-/* aio_read_evt
- * Pull an event off of the ioctx's event ring. Returns the number of
- * events fetched (0 or 1 ;-)
- * FIXME: make this use cmpxchg.
- * TODO: make the ringbuffer user mmap()able (requires FIXME).
+/* aio_read_events
+ * Pull an event off of the ioctx's event ring. Returns the number of
+ * events fetched
*/
-static int aio_read_evt(struct kioctx *ioctx, struct io_event *ent)
+static long aio_read_events_ring(struct kioctx *ctx,
+ struct io_event __user *event, long nr)
{
- struct aio_ring_info *info = &ioctx->ring_info;
struct aio_ring *ring;
- unsigned long head;
- int ret = 0;
+ unsigned head, pos;
+ long ret = 0;
+ int copy_ret;
+
+ mutex_lock(&ctx->ring_lock);
- ring = kmap_atomic(info->ring_pages[0], KM_USER0);
- dprintk("in aio_read_evt h%lu t%lu m%lu\n",
- (unsigned long)ring->head, (unsigned long)ring->tail,
- (unsigned long)ring->nr);
+ ring = kmap_atomic(ctx->ring_pages[0]);
+ head = ring->head;
+ kunmap_atomic(ring);
- if (ring->head == ring->tail)
+ pr_debug("h%u t%u m%u\n", head, ctx->tail, ctx->nr_events);
+
+ if (head == ctx->tail)
goto out;
- spin_lock(&info->ring_lock);
-
- head = ring->head % info->nr;
- if (head != ring->tail) {
- struct io_event *evp = aio_ring_event(info, head, KM_USER1);
- *ent = *evp;
- head = (head + 1) % info->nr;
- smp_mb(); /* finish reading the event before updatng the head */
- ring->head = head;
- ret = 1;
- put_aio_ring_event(evp, KM_USER1);
+ while (ret < nr) {
+ long avail;
+ struct io_event *ev;
+ struct page *page;
+
+ avail = (head <= ctx->tail ? ctx->tail : ctx->nr_events) - head;
+ if (head == ctx->tail)
+ break;
+
+ avail = min(avail, nr - ret);
+ avail = min_t(long, avail, AIO_EVENTS_PER_PAGE -
+ ((head + AIO_EVENTS_OFFSET) % AIO_EVENTS_PER_PAGE));
+
+ pos = head + AIO_EVENTS_OFFSET;
+ page = ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE];
+ pos %= AIO_EVENTS_PER_PAGE;
+
+ ev = kmap(page);
+ copy_ret = copy_to_user(event + ret, ev + pos,
+ sizeof(*ev) * avail);
+ kunmap(page);
+
+ if (unlikely(copy_ret)) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ ret += avail;
+ head += avail;
+ head %= ctx->nr_events;
}
- spin_unlock(&info->ring_lock);
+ ring = kmap_atomic(ctx->ring_pages[0]);
+ ring->head = head;
+ kunmap_atomic(ring);
+ flush_dcache_page(ctx->ring_pages[0]);
+
+ pr_debug("%li h%u t%u\n", ret, head, ctx->tail);
+
+ atomic_sub(ret, &ctx->reqs_active);
out:
- kunmap_atomic(ring, KM_USER0);
- dprintk("leaving aio_read_evt: %d h%lu t%lu\n", ret,
- (unsigned long)ring->head, (unsigned long)ring->tail);
+ mutex_unlock(&ctx->ring_lock);
+
return ret;
}
-struct aio_timeout {
- struct timer_list timer;
- int timed_out;
- struct task_struct *p;
-};
-
-static void timeout_func(unsigned long data)
+static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr,
+ struct io_event __user *event, long *i)
{
- struct aio_timeout *to = (struct aio_timeout *)data;
+ long ret = aio_read_events_ring(ctx, event + *i, nr - *i);
- to->timed_out = 1;
- wake_up_process(to->p);
-}
+ if (ret > 0)
+ *i += ret;
-static inline void init_timeout(struct aio_timeout *to)
-{
- init_timer(&to->timer);
- to->timer.data = (unsigned long)to;
- to->timer.function = timeout_func;
- to->timed_out = 0;
- to->p = current;
-}
+ if (unlikely(atomic_read(&ctx->dead)))
+ ret = -EINVAL;
-static inline void set_timeout(long start_jiffies, struct aio_timeout *to,
- const struct timespec *ts)
-{
- to->timer.expires = start_jiffies + timespec_to_jiffies(ts);
- if (time_after(to->timer.expires, jiffies))
- add_timer(&to->timer);
- else
- to->timed_out = 1;
-}
+ if (!*i)
+ *i = ret;
-static inline void clear_timeout(struct aio_timeout *to)
-{
- del_singleshot_timer_sync(&to->timer);
+ return ret < 0 || *i >= min_nr;
}
-static int read_events(struct kioctx *ctx,
- long min_nr, long nr,
+static long read_events(struct kioctx *ctx, long min_nr, long nr,
struct io_event __user *event,
struct timespec __user *timeout)
{
- long start_jiffies = jiffies;
- struct task_struct *tsk = current;
- DECLARE_WAITQUEUE(wait, tsk);
- int ret;
- int i = 0;
- struct io_event ent;
- struct aio_timeout to;
- int retry = 0;
-
- /* needed to zero any padding within an entry (there shouldn't be
- * any, but C is fun!
- */
- memset(&ent, 0, sizeof(ent));
-retry:
- ret = 0;
- while (likely(i < nr)) {
- ret = aio_read_evt(ctx, &ent);
- if (unlikely(ret <= 0))
- break;
-
- dprintk("read event: %Lx %Lx %Lx %Lx\n",
- ent.data, ent.obj, ent.res, ent.res2);
-
- /* Could we split the check in two? */
- ret = -EFAULT;
- if (unlikely(copy_to_user(event, &ent, sizeof(ent)))) {
- dprintk("aio: lost an event due to EFAULT.\n");
- break;
- }
- ret = 0;
-
- /* Good, event copied to userland, update counts. */
- event ++;
- i ++;
- }
-
- if (min_nr <= i)
- return i;
- if (ret)
- return ret;
-
- /* End fast path */
-
- /* racey check, but it gets redone */
- if (!retry && unlikely(!list_empty(&ctx->run_list))) {
- retry = 1;
- aio_run_all_iocbs(ctx);
- goto retry;
- }
+ ktime_t until = { .tv64 = KTIME_MAX };
+ long ret = 0;
- init_timeout(&to);
if (timeout) {
struct timespec ts;
- ret = -EFAULT;
+
if (unlikely(copy_from_user(&ts, timeout, sizeof(ts))))
- goto out;
+ return -EFAULT;
- set_timeout(start_jiffies, &to, &ts);
+ until = timespec_to_ktime(ts);
}
- while (likely(i < nr)) {
- add_wait_queue_exclusive(&ctx->wait, &wait);
- do {
- set_task_state(tsk, TASK_INTERRUPTIBLE);
- ret = aio_read_evt(ctx, &ent);
- if (ret)
- break;
- if (min_nr <= i)
- break;
- ret = 0;
- if (to.timed_out) /* Only check after read evt */
- break;
- /* Try to only show up in io wait if there are ops
- * in flight */
- if (ctx->reqs_active)
- io_schedule();
- else
- schedule();
- if (signal_pending(tsk)) {
- ret = -EINTR;
- break;
- }
- /*ret = aio_read_evt(ctx, &ent);*/
- } while (1) ;
-
- set_task_state(tsk, TASK_RUNNING);
- remove_wait_queue(&ctx->wait, &wait);
-
- if (unlikely(ret <= 0))
- break;
-
- ret = -EFAULT;
- if (unlikely(copy_to_user(event, &ent, sizeof(ent)))) {
- dprintk("aio: lost an event due to EFAULT.\n");
- break;
- }
-
- /* Good, event copied to userland, update counts. */
- event ++;
- i ++;
- }
+ /*
+ * Note that aio_read_events() is being called as the conditional - i.e.
+ * we're calling it after prepare_to_wait() has set task state to
+ * TASK_INTERRUPTIBLE.
+ *
+ * But aio_read_events() can block, and if it blocks it's going to flip
+ * the task state back to TASK_RUNNING.
+ *
+ * This should be ok, provided it doesn't flip the state back to
+ * TASK_RUNNING and return 0 too much - that causes us to spin. That
+ * will only happen if the mutex_lock() call blocks, and we then find
+ * the ringbuffer empty. So in practice we should be ok, but it's
+ * something to be aware of when touching this code.
+ */
+ wait_event_interruptible_hrtimeout(ctx->wait,
+ aio_read_events(ctx, min_nr, nr, event, &ret), until);
- if (timeout)
- clear_timeout(&to);
-out:
- return i ? i : ret;
-}
+ if (!ret && signal_pending(current))
+ ret = -EINTR;
-/* Take an ioctx and remove it from the list of ioctx's. Protects
- * against races with itself via ->dead.
- */
-static void io_destroy(struct kioctx *ioctx)
-{
- struct mm_struct *mm = current->mm;
- struct kioctx **tmp;
- int was_dead;
-
- /* delete the entry from the list is someone else hasn't already */
- write_lock(&mm->ioctx_list_lock);
- was_dead = ioctx->dead;
- ioctx->dead = 1;
- for (tmp = &mm->ioctx_list; *tmp && *tmp != ioctx;
- tmp = &(*tmp)->next)
- ;
- if (*tmp)
- *tmp = ioctx->next;
- write_unlock(&mm->ioctx_list_lock);
-
- dprintk("aio_release(%p)\n", ioctx);
- if (likely(!was_dead))
- put_ioctx(ioctx); /* twice for the list */
-
- aio_cancel_all(ioctx);
- wait_for_all_aios(ioctx);
- put_ioctx(ioctx); /* once for the lookup */
+ return ret;
}
/* sys_io_setup:
* pointer is passed for ctxp. Will fail with -ENOSYS if not
* implemented.
*/
-asmlinkage long sys_io_setup(unsigned nr_events, aio_context_t __user *ctxp)
+SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
{
struct kioctx *ioctx = NULL;
unsigned long ctx;
ret = PTR_ERR(ioctx);
if (!IS_ERR(ioctx)) {
ret = put_user(ioctx->user_id, ctxp);
- if (!ret)
- return 0;
-
- get_ioctx(ioctx); /* io_destroy() expects us to hold a ref */
- io_destroy(ioctx);
+ if (ret)
+ kill_ioctx(current->mm, ioctx);
+ put_ioctx(ioctx);
}
out:
/* sys_io_destroy:
* Destroy the aio_context specified. May cancel any outstanding
* AIOs and block on completion. Will fail with -ENOSYS if not
- * implemented. May fail with -EFAULT if the context pointed to
+ * implemented. May fail with -EINVAL if the context pointed to
* is invalid.
*/
-asmlinkage long sys_io_destroy(aio_context_t ctx)
+SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
{
struct kioctx *ioctx = lookup_ioctx(ctx);
if (likely(NULL != ioctx)) {
- io_destroy(ioctx);
+ kill_ioctx(current->mm, ioctx);
+ put_ioctx(ioctx);
return 0;
}
pr_debug("EINVAL: io_destroy: invalid context id\n");
BUG_ON(ret > 0 && iocb->ki_left == 0);
}
-static ssize_t aio_rw_vect_retry(struct kiocb *iocb)
+typedef ssize_t (aio_rw_op)(struct kiocb *, const struct iovec *,
+ unsigned long, loff_t);
+
+static ssize_t aio_rw_vect_retry(struct kiocb *iocb, int rw, aio_rw_op *rw_op)
{
struct file *file = iocb->ki_filp;
struct address_space *mapping = file->f_mapping;
struct inode *inode = mapping->host;
- ssize_t (*rw_op)(struct kiocb *, const struct iovec *,
- unsigned long, loff_t);
ssize_t ret = 0;
- unsigned short opcode;
-
- if ((iocb->ki_opcode == IOCB_CMD_PREADV) ||
- (iocb->ki_opcode == IOCB_CMD_PREAD)) {
- rw_op = file->f_op->aio_read;
- opcode = IOCB_CMD_PREADV;
- } else {
- rw_op = file->f_op->aio_write;
- opcode = IOCB_CMD_PWRITEV;
- }
/* This matches the pread()/pwrite() logic */
if (iocb->ki_pos < 0)
return -EINVAL;
+ if (rw == WRITE)
+ file_start_write(file);
do {
ret = rw_op(iocb, &iocb->ki_iovec[iocb->ki_cur_seg],
iocb->ki_nr_segs - iocb->ki_cur_seg,
/* retry all partial writes. retry partial reads as long as its a
* regular file. */
} while (ret > 0 && iocb->ki_left > 0 &&
- (opcode == IOCB_CMD_PWRITEV ||
+ (rw == WRITE ||
(!S_ISFIFO(inode->i_mode) && !S_ISSOCK(inode->i_mode))));
+ if (rw == WRITE)
+ file_end_write(file);
/* This means we must have transferred all that we could */
/* No need to retry anymore */
/* If we managed to write some out we return that, rather than
* the eventual error. */
- if (opcode == IOCB_CMD_PWRITEV
- && ret < 0 && ret != -EIOCBQUEUED && ret != -EIOCBRETRY
+ if (rw == WRITE
+ && ret < 0 && ret != -EIOCBQUEUED
&& iocb->ki_nbytes - iocb->ki_left)
ret = iocb->ki_nbytes - iocb->ki_left;
return ret;
}
-static 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;
-}
-
-static 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;
-}
-
-static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb)
+static ssize_t aio_setup_vectored_rw(int rw, struct kiocb *kiocb, bool compat)
{
ssize_t ret;
- ret = rw_copy_check_uvector(type, (struct iovec __user *)kiocb->ki_buf,
- kiocb->ki_nbytes, 1,
- &kiocb->ki_inline_vec, &kiocb->ki_iovec);
+ kiocb->ki_nr_segs = kiocb->ki_nbytes;
+
+#ifdef CONFIG_COMPAT
+ if (compat)
+ ret = compat_rw_copy_check_uvector(rw,
+ (struct compat_iovec __user *)kiocb->ki_buf,
+ kiocb->ki_nr_segs, 1, &kiocb->ki_inline_vec,
+ &kiocb->ki_iovec);
+ else
+#endif
+ ret = rw_copy_check_uvector(rw,
+ (struct iovec __user *)kiocb->ki_buf,
+ kiocb->ki_nr_segs, 1, &kiocb->ki_inline_vec,
+ &kiocb->ki_iovec);
if (ret < 0)
- goto out;
+ return ret;
- kiocb->ki_nr_segs = kiocb->ki_nbytes;
- kiocb->ki_cur_seg = 0;
- /* ki_nbytes/left now reflect bytes instead of segs */
+ /* ki_nbytes now reflect bytes instead of segs */
kiocb->ki_nbytes = ret;
- kiocb->ki_left = ret;
-
- ret = 0;
-out:
- return ret;
+ return 0;
}
-static ssize_t aio_setup_single_vector(struct kiocb *kiocb)
+static ssize_t aio_setup_single_vector(int rw, struct kiocb *kiocb)
{
+ if (unlikely(!access_ok(!rw, kiocb->ki_buf, kiocb->ki_nbytes)))
+ return -EFAULT;
+
kiocb->ki_iovec = &kiocb->ki_inline_vec;
kiocb->ki_iovec->iov_base = kiocb->ki_buf;
- kiocb->ki_iovec->iov_len = kiocb->ki_left;
+ kiocb->ki_iovec->iov_len = kiocb->ki_nbytes;
kiocb->ki_nr_segs = 1;
- kiocb->ki_cur_seg = 0;
return 0;
}
* Performs the initial checks and aio retry method
* setup for the kiocb at the time of io submission.
*/
-static ssize_t aio_setup_iocb(struct kiocb *kiocb)
+static ssize_t aio_run_iocb(struct kiocb *req, bool compat)
{
- struct file *file = kiocb->ki_filp;
- ssize_t ret = 0;
+ struct file *file = req->ki_filp;
+ ssize_t ret;
+ int rw;
+ fmode_t mode;
+ aio_rw_op *rw_op;
- switch (kiocb->ki_opcode) {
+ switch (req->ki_opcode) {
case IOCB_CMD_PREAD:
- ret = -EBADF;
- if (unlikely(!(file->f_mode & FMODE_READ)))
- break;
- ret = -EFAULT;
- if (unlikely(!access_ok(VERIFY_WRITE, kiocb->ki_buf,
- kiocb->ki_left)))
- break;
- ret = security_file_permission(file, MAY_READ);
- if (unlikely(ret))
- break;
- ret = aio_setup_single_vector(kiocb);
- if (ret)
- break;
- ret = -EINVAL;
- if (file->f_op->aio_read)
- kiocb->ki_retry = aio_rw_vect_retry;
- break;
- case IOCB_CMD_PWRITE:
- ret = -EBADF;
- if (unlikely(!(file->f_mode & FMODE_WRITE)))
- break;
- ret = -EFAULT;
- if (unlikely(!access_ok(VERIFY_READ, kiocb->ki_buf,
- kiocb->ki_left)))
- break;
- ret = security_file_permission(file, MAY_WRITE);
- if (unlikely(ret))
- break;
- ret = aio_setup_single_vector(kiocb);
- if (ret)
- break;
- ret = -EINVAL;
- if (file->f_op->aio_write)
- kiocb->ki_retry = aio_rw_vect_retry;
- break;
case IOCB_CMD_PREADV:
- ret = -EBADF;
- if (unlikely(!(file->f_mode & FMODE_READ)))
- break;
- ret = security_file_permission(file, MAY_READ);
- if (unlikely(ret))
- break;
- ret = aio_setup_vectored_rw(READ, kiocb);
- if (ret)
- break;
- ret = -EINVAL;
- if (file->f_op->aio_read)
- kiocb->ki_retry = aio_rw_vect_retry;
- break;
+ mode = FMODE_READ;
+ rw = READ;
+ rw_op = file->f_op->aio_read;
+ goto rw_common;
+
+ case IOCB_CMD_PWRITE:
case IOCB_CMD_PWRITEV:
- ret = -EBADF;
- if (unlikely(!(file->f_mode & FMODE_WRITE)))
- break;
- ret = security_file_permission(file, MAY_WRITE);
- if (unlikely(ret))
- break;
- ret = aio_setup_vectored_rw(WRITE, kiocb);
+ mode = FMODE_WRITE;
+ rw = WRITE;
+ rw_op = file->f_op->aio_write;
+ goto rw_common;
+rw_common:
+ if (unlikely(!(file->f_mode & mode)))
+ return -EBADF;
+
+ if (!rw_op)
+ return -EINVAL;
+
+ ret = (req->ki_opcode == IOCB_CMD_PREADV ||
+ req->ki_opcode == IOCB_CMD_PWRITEV)
+ ? aio_setup_vectored_rw(rw, req, compat)
+ : aio_setup_single_vector(rw, req);
if (ret)
- break;
- ret = -EINVAL;
- if (file->f_op->aio_write)
- kiocb->ki_retry = aio_rw_vect_retry;
+ return ret;
+
+ ret = rw_verify_area(rw, file, &req->ki_pos, req->ki_nbytes);
+ if (ret < 0)
+ return ret;
+
+ req->ki_nbytes = ret;
+ req->ki_left = ret;
+
+ ret = aio_rw_vect_retry(req, rw, rw_op);
break;
+
case IOCB_CMD_FDSYNC:
- ret = -EINVAL;
- if (file->f_op->aio_fsync)
- kiocb->ki_retry = aio_fdsync;
+ if (!file->f_op->aio_fsync)
+ return -EINVAL;
+
+ ret = file->f_op->aio_fsync(req, 1);
break;
+
case IOCB_CMD_FSYNC:
- ret = -EINVAL;
- if (file->f_op->aio_fsync)
- kiocb->ki_retry = aio_fsync;
+ if (!file->f_op->aio_fsync)
+ return -EINVAL;
+
+ ret = file->f_op->aio_fsync(req, 0);
break;
+
default:
- dprintk("EINVAL: io_submit: no operation provided\n");
- ret = -EINVAL;
+ pr_debug("EINVAL: no operation provided\n");
+ return -EINVAL;
}
- if (!kiocb->ki_retry)
- return ret;
+ if (ret != -EIOCBQUEUED) {
+ /*
+ * There's no easy way to restart the syscall since other AIO's
+ * may be already running. Just fail this IO with EINTR.
+ */
+ if (unlikely(ret == -ERESTARTSYS || ret == -ERESTARTNOINTR ||
+ ret == -ERESTARTNOHAND ||
+ ret == -ERESTART_RESTARTBLOCK))
+ ret = -EINTR;
+ aio_complete(req, ret, 0);
+ }
return 0;
}
-/*
- * aio_wake_function:
- * wait queue callback function for aio notification,
- * Simply triggers a retry of the operation via kick_iocb.
- *
- * This callback is specified in the wait queue entry in
- * a kiocb.
- *
- * Note:
- * This routine is executed with the wait queue lock held.
- * Since kick_iocb acquires iocb->ctx->ctx_lock, it nests
- * the ioctx lock inside the wait queue lock. This is safe
- * because this callback isn't used for wait queues which
- * are nested inside ioctx lock (i.e. ctx->wait)
- */
-static int aio_wake_function(wait_queue_t *wait, unsigned mode,
- int sync, void *key)
-{
- struct kiocb *iocb = container_of(wait, struct kiocb, ki_wait);
-
- list_del_init(&wait->task_list);
- kick_iocb(iocb);
- return 1;
-}
-
-int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
- struct iocb *iocb)
+static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
+ struct iocb *iocb, bool compat)
{
struct kiocb *req;
- struct file *file;
ssize_t ret;
/* enforce forwards compatibility on users */
if (unlikely(iocb->aio_reserved1 || iocb->aio_reserved2)) {
- pr_debug("EINVAL: io_submit: reserve field set\n");
+ pr_debug("EINVAL: reserve field set\n");
return -EINVAL;
}
return -EINVAL;
}
- file = fget(iocb->aio_fildes);
- if (unlikely(!file))
- return -EBADF;
-
- req = aio_get_req(ctx); /* returns with 2 references to req */
- if (unlikely(!req)) {
- fput(file);
+ req = aio_get_req(ctx);
+ if (unlikely(!req))
return -EAGAIN;
+
+ req->ki_filp = fget(iocb->aio_fildes);
+ if (unlikely(!req->ki_filp)) {
+ ret = -EBADF;
+ goto out_put_req;
}
- req->ki_filp = file;
+
if (iocb->aio_flags & IOCB_FLAG_RESFD) {
/*
* If the IOCB_FLAG_RESFD flag of aio_flags is set, get an
* an eventfd() fd, and will be signaled for each completed
* event using the eventfd_signal() function.
*/
- req->ki_eventfd = eventfd_fget((int) iocb->aio_resfd);
- if (unlikely(IS_ERR(req->ki_eventfd))) {
+ req->ki_eventfd = eventfd_ctx_fdget((int) iocb->aio_resfd);
+ if (IS_ERR(req->ki_eventfd)) {
ret = PTR_ERR(req->ki_eventfd);
+ req->ki_eventfd = NULL;
goto out_put_req;
}
}
- ret = put_user(req->ki_key, &user_iocb->aio_key);
+ ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
if (unlikely(ret)) {
- dprintk("EFAULT: aio_key\n");
+ pr_debug("EFAULT: aio_key\n");
goto out_put_req;
}
req->ki_buf = (char __user *)(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);
-
- ret = aio_setup_iocb(req);
+ ret = aio_run_iocb(req, compat);
if (ret)
goto out_put_req;
- spin_lock_irq(&ctx->ctx_lock);
- aio_run_iocb(req);
- if (!list_empty(&ctx->run_list)) {
- /* drain the run list */
- while (__aio_run_iocbs(ctx))
- ;
- }
- spin_unlock_irq(&ctx->ctx_lock);
aio_put_req(req); /* drop extra ref to req */
return 0;
-
out_put_req:
+ atomic_dec(&ctx->reqs_active);
aio_put_req(req); /* drop extra ref to req */
aio_put_req(req); /* drop i/o ref to req */
return ret;
}
-/* sys_io_submit:
- * Queue the nr iocbs pointed to by iocbpp for processing. Returns
- * the number of iocbs queued. May return -EINVAL if the aio_context
- * specified by ctx_id is invalid, if nr is < 0, if the iocb at
- * *iocbpp[0] is not properly initialized, if the operation specified
- * is invalid for the file descriptor in the iocb. May fail with
- * -EFAULT if any of the data structures point to invalid data. May
- * fail with -EBADF if the file descriptor specified in the first
- * iocb is invalid. May fail with -EAGAIN if insufficient resources
- * are available to queue any iocbs. Will return 0 if nr is 0. Will
- * fail with -ENOSYS if not implemented.
- */
-asmlinkage long sys_io_submit(aio_context_t ctx_id, long nr,
- struct iocb __user * __user *iocbpp)
+long do_io_submit(aio_context_t ctx_id, long nr,
+ struct iocb __user *__user *iocbpp, bool compat)
{
struct kioctx *ctx;
long ret = 0;
- int i;
+ int i = 0;
+ struct blk_plug plug;
if (unlikely(nr < 0))
return -EINVAL;
+ if (unlikely(nr > LONG_MAX/sizeof(*iocbpp)))
+ nr = LONG_MAX/sizeof(*iocbpp);
+
if (unlikely(!access_ok(VERIFY_READ, iocbpp, (nr*sizeof(*iocbpp)))))
return -EFAULT;
ctx = lookup_ioctx(ctx_id);
if (unlikely(!ctx)) {
- pr_debug("EINVAL: io_submit: invalid context id\n");
+ pr_debug("EINVAL: invalid context id\n");
return -EINVAL;
}
+ blk_start_plug(&plug);
+
/*
* AKPM: should this return a partial result if some of the IOs were
* successfully submitted?
break;
}
- ret = io_submit_one(ctx, user_iocb, &tmp);
+ ret = io_submit_one(ctx, user_iocb, &tmp, compat);
if (ret)
break;
}
+ blk_finish_plug(&plug);
put_ioctx(ctx);
return i ? i : ret;
}
+/* sys_io_submit:
+ * Queue the nr iocbs pointed to by iocbpp for processing. Returns
+ * the number of iocbs queued. May return -EINVAL if the aio_context
+ * specified by ctx_id is invalid, if nr is < 0, if the iocb at
+ * *iocbpp[0] is not properly initialized, if the operation specified
+ * is invalid for the file descriptor in the iocb. May fail with
+ * -EFAULT if any of the data structures point to invalid data. May
+ * fail with -EBADF if the file descriptor specified in the first
+ * iocb is invalid. May fail with -EAGAIN if insufficient resources
+ * are available to queue any iocbs. Will return 0 if nr is 0. Will
+ * fail with -ENOSYS if not implemented.
+ */
+SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
+ struct iocb __user * __user *, iocbpp)
+{
+ return do_io_submit(ctx_id, nr, iocbpp, 0);
+}
+
/* lookup_kiocb
* Finds a given iocb for cancellation.
*/
assert_spin_locked(&ctx->ctx_lock);
+ if (key != KIOCB_KEY)
+ return NULL;
+
/* TODO: use a hash or array, this sucks. */
list_for_each(pos, &ctx->active_reqs) {
struct kiocb *kiocb = list_kiocb(pos);
- if (kiocb->ki_obj.user == iocb && kiocb->ki_key == key)
+ if (kiocb->ki_obj.user == iocb)
return kiocb;
}
return NULL;
* invalid. May fail with -EAGAIN if the iocb specified was not
* cancelled. Will fail with -ENOSYS if not implemented.
*/
-asmlinkage long sys_io_cancel(aio_context_t ctx_id, struct iocb __user *iocb,
- struct io_event __user *result)
+SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
+ struct io_event __user *, result)
{
- int (*cancel)(struct kiocb *iocb, struct io_event *res);
+ struct io_event res;
struct kioctx *ctx;
struct kiocb *kiocb;
u32 key;
return -EINVAL;
spin_lock_irq(&ctx->ctx_lock);
- ret = -EAGAIN;
+
kiocb = lookup_kiocb(ctx, iocb, key);
- if (kiocb && kiocb->ki_cancel) {
- cancel = kiocb->ki_cancel;
- kiocb->ki_users ++;
- kiocbSetCancelled(kiocb);
- } else
- cancel = NULL;
+ if (kiocb)
+ ret = kiocb_cancel(ctx, kiocb, &res);
+ else
+ ret = -EINVAL;
+
spin_unlock_irq(&ctx->ctx_lock);
- if (NULL != cancel) {
- struct io_event tmp;
- pr_debug("calling cancel\n");
- memset(&tmp, 0, sizeof(tmp));
- tmp.obj = (u64)(unsigned long)kiocb->ki_obj.user;
- tmp.data = kiocb->ki_user_data;
- ret = cancel(kiocb, &tmp);
- if (!ret) {
- /* Cancellation succeeded -- copy the result
- * into the user's buffer.
- */
- if (copy_to_user(result, &tmp, sizeof(tmp)))
- ret = -EFAULT;
- }
- } else
- ret = -EINVAL;
+ if (!ret) {
+ /* Cancellation succeeded -- copy the result
+ * into the user's buffer.
+ */
+ if (copy_to_user(result, &res, sizeof(res)))
+ ret = -EFAULT;
+ }
put_ioctx(ctx);
/* io_getevents:
* Attempts to read at least min_nr events and up to nr events from
- * the completion queue for the aio_context specified by ctx_id. May
- * fail with -EINVAL if ctx_id is invalid, if min_nr is out of range,
- * if nr is out of range, if when is out of range. May fail with
- * -EFAULT if any of the memory specified to is invalid. May return
- * 0 or < min_nr if no events are available and the timeout specified
- * by when has elapsed, where when == NULL specifies an infinite
- * timeout. Note that the timeout pointed to by when is relative and
- * will be updated if not NULL and the operation blocks. Will fail
- * with -ENOSYS if not implemented.
+ * the completion queue for the aio_context specified by ctx_id. If
+ * it succeeds, the number of read events is returned. May fail with
+ * -EINVAL if ctx_id is invalid, if min_nr is out of range, if nr is
+ * out of range, if timeout is out of range. May fail with -EFAULT
+ * if any of the memory specified is invalid. May return 0 or
+ * < min_nr if the timeout specified by timeout has elapsed
+ * before sufficient events are available, where timeout == NULL
+ * specifies an infinite timeout. Note that the timeout pointed to by
+ * timeout is relative. Will fail with -ENOSYS if not implemented.
*/
-asmlinkage long sys_io_getevents(aio_context_t ctx_id,
- long min_nr,
- long nr,
- struct io_event __user *events,
- struct timespec __user *timeout)
+SYSCALL_DEFINE5(io_getevents, aio_context_t, ctx_id,
+ long, min_nr,
+ long, nr,
+ struct io_event __user *, events,
+ struct timespec __user *, timeout)
{
struct kioctx *ioctx = lookup_ioctx(ctx_id);
long ret = -EINVAL;
if (likely(ioctx)) {
- if (likely(min_nr <= nr && min_nr >= 0 && nr >= 0))
+ if (likely(min_nr <= nr && min_nr >= 0))
ret = read_events(ioctx, min_nr, nr, events, timeout);
put_ioctx(ioctx);
}
-
return ret;
}
-
-__initcall(aio_setup);
-
-EXPORT_SYMBOL(aio_complete);
-EXPORT_SYMBOL(aio_put_req);
-EXPORT_SYMBOL(wait_on_sync_kiocb);
Code Review / linux-3.10.git / blobdiff