#include <linux/highmem.h>
#include <linux/workqueue.h>
#include <linux/security.h>
+#include <linux/eventfd.h>
#include <asm/kmap_types.h>
#include <asm/uaccess.h>
kunmap_atomic((void *)((unsigned long)__event & PAGE_MASK), km); \
} while(0)
+static void ctx_rcu_free(struct rcu_head *head)
+{
+ struct kioctx *ctx = container_of(head, struct kioctx, rcu_head);
+ unsigned nr_events = ctx->max_reqs;
+
+ kmem_cache_free(kioctx_cachep, ctx);
+
+ 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);
+ }
+}
+
+/* __put_ioctx
+ * Called when the last user of an aio context has gone away,
+ * and the struct needs to be freed.
+ */
+static void __put_ioctx(struct kioctx *ctx)
+{
+ 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);
+ call_rcu(&ctx->rcu_head, ctx_rcu_free);
+}
+
+#define get_ioctx(kioctx) do { \
+ BUG_ON(atomic_read(&(kioctx)->users) <= 0); \
+ atomic_inc(&(kioctx)->users); \
+} while (0)
+#define put_ioctx(kioctx) do { \
+ BUG_ON(atomic_read(&(kioctx)->users) <= 0); \
+ if (unlikely(atomic_dec_and_test(&(kioctx)->users))) \
+ __put_ioctx(kioctx); \
+} while (0)
+
/* ioctx_alloc
* Allocates and initializes an ioctx. Returns an ERR_PTR if it failed.
*/
{
struct mm_struct *mm;
struct kioctx *ctx;
+ int did_sync = 0;
/* Prevent overflows */
if ((nr_events > (0x10000000U / sizeof(struct io_event))) ||
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);
+ do {
+ spin_lock_bh(&aio_nr_lock);
+ if (aio_nr + nr_events > aio_max_nr ||
+ aio_nr + nr_events < aio_nr)
+ ctx->max_reqs = 0;
+ else
+ aio_nr += ctx->max_reqs;
+ spin_unlock_bh(&aio_nr_lock);
+ if (ctx->max_reqs || did_sync)
+ break;
+
+ /* wait for rcu callbacks to have completed before giving up */
+ synchronize_rcu();
+ did_sync = 1;
+ ctx->max_reqs = nr_events;
+ } while (1);
+
if (ctx->max_reqs == 0)
goto out_cleanup;
- /* 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);
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
while (ctx->reqs_active) {
spin_unlock_irq(&ctx->ctx_lock);
- schedule();
+ io_schedule();
set_task_state(tsk, TASK_UNINTERRUPTIBLE);
spin_lock_irq(&ctx->ctx_lock);
}
/* wait_on_sync_kiocb:
* Waits on the given sync kiocb to complete.
*/
-ssize_t fastcall wait_on_sync_kiocb(struct kiocb *iocb)
+ssize_t wait_on_sync_kiocb(struct kiocb *iocb)
{
while (iocb->ki_users) {
set_current_state(TASK_UNINTERRUPTIBLE);
if (!iocb->ki_users)
break;
- schedule();
+ io_schedule();
}
__set_current_state(TASK_RUNNING);
return iocb->ki_user_data;
* go away, they will call put_ioctx and release any pinned memory
* associated with the request (held via struct page * references).
*/
-void fastcall exit_aio(struct mm_struct *mm)
+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;
+ struct kioctx *ctx;
+
+ while (!hlist_empty(&mm->ioctx_list)) {
+ ctx = hlist_entry(mm->ioctx_list.first, struct kioctx, list);
+ hlist_del_rcu(&ctx->list);
+
aio_cancel_all(ctx);
wait_for_all_aios(ctx);
/*
* Ensure we don't leave the ctx on the aio_wq
*/
- flush_work(aio_wq, &ctx->wq.work);
+ cancel_work_sync(&ctx->wq.work);
if (1 != atomic_read(&ctx->users))
printk(KERN_DEBUG
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 fastcall __put_ioctx(struct kioctx *ctx)
-{
- unsigned nr_events = ctx->max_reqs;
-
- BUG_ON(ctx->reqs_active);
-
- cancel_delayed_work(&ctx->wq);
- flush_work(aio_wq, &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);
-
- 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);
}
}
* This prevents races between the aio code path referencing the
* req (after submitting it) and aio_complete() freeing the req.
*/
-static struct kiocb *FASTCALL(__aio_get_req(struct kioctx *ctx));
-static struct kiocb fastcall *__aio_get_req(struct kioctx *ctx)
+static struct kiocb *__aio_get_req(struct kioctx *ctx)
{
struct kiocb *req = NULL;
struct aio_ring *ring;
req->private = NULL;
req->ki_iovec = NULL;
INIT_LIST_HEAD(&req->ki_run_list);
+ req->ki_eventfd = NULL;
/* Check if the completion queue has enough free space to
* accept an event from this io.
list_del(&req->ki_list);
spin_unlock_irq(&fput_lock);
- /* Complete the fput */
- __fput(req->ki_filp);
+ /* Complete the fput(s) */
+ if (req->ki_filp != NULL)
+ __fput(req->ki_filp);
+ if (req->ki_eventfd != NULL)
+ __fput(req->ki_eventfd);
/* Link the iocb into the context's free list */
spin_lock_irq(&ctx->ctx_lock);
*/
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));
+ int schedule_putreq = 0;
+
+ dprintk(KERN_DEBUG "aio_put(%p): f_count=%ld\n",
+ req, atomic_long_read(&req->ki_filp->f_count));
assert_spin_locked(&ctx->ctx_lock);
- req->ki_users --;
+ req->ki_users--;
BUG_ON(req->ki_users < 0);
if (likely(req->ki_users))
return 0;
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.
+ /*
+ * Try to optimize the aio and eventfd file* puts, by avoiding to
+ * schedule work in case it is not __fput() time. In normal cases,
+ * we would not be holding the last reference to the file*, so
+ * this function will be executed w/out any aio kthread wakeup.
*/
- if (unlikely(atomic_dec_and_test(&req->ki_filp->f_count))) {
+ if (unlikely(atomic_long_dec_and_test(&req->ki_filp->f_count)))
+ schedule_putreq++;
+ else
+ req->ki_filp = NULL;
+ if (req->ki_eventfd != NULL) {
+ if (unlikely(atomic_long_dec_and_test(&req->ki_eventfd->f_count)))
+ schedule_putreq++;
+ else
+ req->ki_eventfd = NULL;
+ }
+ if (unlikely(schedule_putreq)) {
get_ioctx(ctx);
spin_lock(&fput_lock);
list_add(&req->ki_list, &fput_head);
* Returns true if this put was the last user of the kiocb,
* false if the request is still in use.
*/
-int fastcall aio_put_req(struct kiocb *req)
+int aio_put_req(struct kiocb *req)
{
struct kioctx *ctx = req->ki_ctx;
int ret;
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)
+static struct kioctx *lookup_ioctx(unsigned long ctx_id)
{
- struct kioctx *ioctx;
- struct mm_struct *mm;
+ struct mm_struct *mm = current->mm;
+ struct kioctx *ctx, *ret = NULL;
+ struct hlist_node *n;
- 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);
+ rcu_read_lock();
+
+ hlist_for_each_entry_rcu(ctx, n, &mm->ioctx_list, list) {
+ if (ctx->user_id == ctx_id && !ctx->dead) {
+ get_ioctx(ctx);
+ ret = ctx;
break;
}
- read_unlock(&mm->ioctx_list_lock);
+ }
- return ioctx;
+ rcu_read_unlock();
+ return ret;
}
/*
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);
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);
/*
* Now we are all set to call the retry method in async
- * context. By setting this thread's io_wait context
- * to point to the wait queue entry inside the currently
- * running iocb for the duration of the retry, we ensure
- * that async notification wakeups are queued by the
- * operation instead of blocking waits, and when notified,
- * cause the iocb to be kicked for continuation (through
- * the aio_wake_function callback).
+ * context.
*/
- BUG_ON(current->io_wait != NULL);
- current->io_wait = &iocb->ki_wait;
ret = retry(iocb);
- current->io_wait = NULL;
if (ret != -EIOCBRETRY && ret != -EIOCBQUEUED) {
BUG_ON(!list_empty(&iocb->ki_wait.task_list));
* The retry is usually executed by aio workqueue
* threads (See aio_kick_handler).
*/
-void fastcall kick_iocb(struct kiocb *iocb)
+void kick_iocb(struct kiocb *iocb)
{
/* sync iocbs are easy: they can only ever be executing from a
* single context. */
* Returns true if this is the last user of the request. The
* only other user of the request can be the cancellation code.
*/
-int fastcall aio_complete(struct kiocb *iocb, long res, long res2)
+int aio_complete(struct kiocb *iocb, long res, long res2)
{
struct kioctx *ctx = iocb->ki_ctx;
struct aio_ring_info *info;
kunmap_atomic(ring, KM_IRQ1);
pr_debug("added to ring %p at [%lu]\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);
+
put_rq:
/* everything turned out well, dispose of the aiocb. */
ret = __aio_put_req(ctx, 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);
static inline void init_timeout(struct aio_timeout *to)
{
- init_timer(&to->timer);
- to->timer.data = (unsigned long)to;
- to->timer.function = timeout_func;
+ setup_timer_on_stack(&to->timer, timeout_func, (unsigned long) to);
to->timed_out = 0;
to->p = current;
}
break;
if (min_nr <= i)
break;
- ret = 0;
+ if (unlikely(ctx->dead)) {
+ ret = -EINVAL;
+ break;
+ }
if (to.timed_out) /* Only check after read evt */
break;
- schedule();
+ /* 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;
if (timeout)
clear_timeout(&to);
out:
+ destroy_timer_on_stack(&to.timer);
return i ? i : ret;
}
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);
+ spin_lock(&mm->ioctx_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);
+ hlist_del_rcu(&ioctx->list);
+ spin_unlock(&mm->ioctx_lock);
dprintk("aio_release(%p)\n", ioctx);
if (likely(!was_dead))
aio_cancel_all(ioctx);
wait_for_all_aios(ioctx);
+
+ /*
+ * Wake up any waiters. The setting of ctx->dead must be seen
+ * by other CPUs at this point. Right now, we rely on the
+ * locking done by the above calls to ensure this consistency.
+ */
+ wake_up(&ioctx->wait);
put_ioctx(ioctx); /* once for the lookup */
}
* 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;
* implemented. May fail with -EFAULT 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)) {
opcode = IOCB_CMD_PWRITEV;
}
+ /* This matches the pread()/pwrite() logic */
+ if (iocb->ki_pos < 0)
+ return -EINVAL;
+
do {
ret = rw_op(iocb, &iocb->ki_iovec[iocb->ki_cur_seg],
iocb->ki_nr_segs - iocb->ki_cur_seg,
if ((ret == 0) || (iocb->ki_left == 0))
ret = iocb->ki_nbytes - iocb->ki_left;
+ /* 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
+ && iocb->ki_nbytes - iocb->ki_left)
+ ret = iocb->ki_nbytes - iocb->ki_left;
+
return ret;
}
* Simply triggers a retry of the operation via kick_iocb.
*
* This callback is specified in the wait queue entry in
- * a kiocb (current->io_wait points to this wait queue
- * entry when an aio operation executes; it is used
- * instead of a synchronous wait when an i/o blocking
- * condition is encountered during aio).
+ * a kiocb.
*
* Note:
* This routine is executed with the wait queue lock held.
return 1;
}
-int fastcall io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
+static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
struct iocb *iocb)
{
struct kiocb *req;
ssize_t ret;
/* enforce forwards compatibility on users */
- if (unlikely(iocb->aio_reserved1 || iocb->aio_reserved2 ||
- iocb->aio_reserved3)) {
+ if (unlikely(iocb->aio_reserved1 || iocb->aio_reserved2)) {
pr_debug("EINVAL: io_submit: reserve field set\n");
return -EINVAL;
}
fput(file);
return -EAGAIN;
}
-
req->ki_filp = file;
+ if (iocb->aio_flags & IOCB_FLAG_RESFD) {
+ /*
+ * If the IOCB_FLAG_RESFD flag of aio_flags is set, get an
+ * instance of the file* now. The file descriptor must be
+ * 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 (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);
if (unlikely(ret)) {
dprintk("EFAULT: aio_key\n");
* 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)
+SYSCALL_DEFINE3(io_submit, aio_context_t, ctx_id, long, nr,
+ struct iocb __user * __user *, iocbpp)
{
struct kioctx *ctx;
long ret = 0;
* 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 kioctx *ctx;
* will be updated if not NULL and the operation blocks. 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;
put_ioctx(ioctx);
}
+ asmlinkage_protect(5, ret, ctx_id, min_nr, nr, events, timeout);
return ret;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff