#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 <asm/kmap_types.h>
#include <asm/uaccess.h>
-#include <asm/mmu_context.h>
#if DEBUG > 1
#define dprintk printk
return 0;
}
+__initcall(aio_setup);
static void aio_free_ring(struct kioctx *ctx)
{
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,
*/
static void __put_ioctx(struct kioctx *ctx)
{
- unsigned nr_events = ctx->max_reqs;
-
BUG_ON(ctx->reqs_active);
cancel_delayed_work(&ctx->wq);
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);
- }
+ call_rcu(&ctx->rcu_head, ctx_rcu_free);
}
#define get_ioctx(kioctx) do { \
{
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_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
*/
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);
atomic_read(&ctx->users), ctx->dead,
ctx->reqs_active);
put_ioctx(ctx);
- ctx = next;
}
}
req->private = NULL;
req->ki_iovec = NULL;
INIT_LIST_HEAD(&req->ki_run_list);
- req->ki_eventfd = ERR_PTR(-EINVAL);
+ req->ki_eventfd = NULL;
/* Check if the completion queue has enough free space to
* accept an event from this io.
{
assert_spin_locked(&ctx->ctx_lock);
- if (!IS_ERR(req->ki_eventfd))
- fput(req->ki_eventfd);
+ 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)
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);
/* 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));
+ 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))) {
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
+ } else {
+ req->ki_filp = NULL;
really_put_req(ctx, req);
+ }
return 1;
}
spin_unlock_irq(&ctx->ctx_lock);
return ret;
}
+EXPORT_SYMBOL(aio_put_req);
-/* Lookup an ioctx id. ioctx_list is lockless for reads.
- * FIXME: this is O(n) and is only suitable for development.
- */
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;
-}
-
-/*
- * 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);
+ rcu_read_unlock();
+ return ret;
}
/*
* eventfd. The eventfd_signal() function is safe to be called
* from IRQ context.
*/
- if (!IS_ERR(iocb->ki_eventfd))
+ if (iocb->ki_eventfd != NULL)
eventfd_signal(iocb->ki_eventfd, 1);
put_rq:
spin_unlock_irqrestore(&ctx->ctx_lock, flags);
return ret;
}
+EXPORT_SYMBOL(aio_complete);
/* aio_read_evt
* Pull an event off of the ioctx's event ring. Returns the number of
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;
}
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))
* 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)) {
* 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);
+ 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;
}
}
* 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;
asmlinkage_protect(5, ret, ctx_id, min_nr, nr, events, timeout);
return ret;
}
-
-__initcall(aio_setup);
-
-EXPORT_SYMBOL(aio_complete);
-EXPORT_SYMBOL(aio_put_req);
-EXPORT_SYMBOL(wait_on_sync_kiocb);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff