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@@ -8,6 +8,8 @@
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*
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* See ../COPYING for licensing terms.
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*/
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+#define pr_fmt(fmt) "%s: " fmt, __func__
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+
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#include <linux/kernel.h>
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#include <linux/init.h>
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#include <linux/errno.h>
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@@ -18,8 +20,6 @@
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#include <linux/backing-dev.h>
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#include <linux/uio.h>
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-#define DEBUG 0
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-
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#include <linux/sched.h>
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#include <linux/fs.h>
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#include <linux/file.h>
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@@ -39,11 +39,76 @@
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#include <asm/kmap_types.h>
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#include <asm/uaccess.h>
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-#if DEBUG > 1
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-#define dprintk printk
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-#else
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-#define dprintk(x...) do { ; } while (0)
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-#endif
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+#define AIO_RING_MAGIC 0xa10a10a1
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+#define AIO_RING_COMPAT_FEATURES 1
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+#define AIO_RING_INCOMPAT_FEATURES 0
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+struct aio_ring {
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+ unsigned id; /* kernel internal index number */
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+ unsigned nr; /* number of io_events */
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+ unsigned head;
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+ unsigned tail;
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+
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+ unsigned magic;
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+ unsigned compat_features;
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+ unsigned incompat_features;
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+ unsigned header_length; /* size of aio_ring */
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+
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+
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+ struct io_event io_events[0];
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+}; /* 128 bytes + ring size */
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+
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+#define AIO_RING_PAGES 8
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+
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+struct kioctx {
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+ atomic_t users;
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+ atomic_t dead;
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+
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+ /* This needs improving */
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+ unsigned long user_id;
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+ struct hlist_node list;
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+
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+ /*
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+ * This is what userspace passed to io_setup(), it's not used for
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+ * anything but counting against the global max_reqs quota.
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+ *
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+ * The real limit is nr_events - 1, which will be larger (see
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+ * aio_setup_ring())
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+ */
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+ unsigned max_reqs;
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+
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+ /* Size of ringbuffer, in units of struct io_event */
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+ unsigned nr_events;
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+
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+ unsigned long mmap_base;
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+ unsigned long mmap_size;
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+
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+ struct page **ring_pages;
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+ long nr_pages;
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+
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+ struct rcu_head rcu_head;
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+ struct work_struct rcu_work;
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+
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+ struct {
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+ atomic_t reqs_active;
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+ } ____cacheline_aligned_in_smp;
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+
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+ struct {
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+ spinlock_t ctx_lock;
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+ struct list_head active_reqs; /* used for cancellation */
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+ } ____cacheline_aligned_in_smp;
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+
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+ struct {
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+ struct mutex ring_lock;
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+ wait_queue_head_t wait;
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+ } ____cacheline_aligned_in_smp;
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+
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+ struct {
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+ unsigned tail;
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+ spinlock_t completion_lock;
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+ } ____cacheline_aligned_in_smp;
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+
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+ struct page *internal_pages[AIO_RING_PAGES];
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+};
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/*------ sysctl variables----*/
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static DEFINE_SPINLOCK(aio_nr_lock);
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@@ -54,11 +119,6 @@ unsigned long aio_max_nr = 0x10000; /* system wide maximum number of aio request
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static struct kmem_cache *kiocb_cachep;
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static struct kmem_cache *kioctx_cachep;
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-static struct workqueue_struct *aio_wq;
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-
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-static void aio_kick_handler(struct work_struct *);
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-static void aio_queue_work(struct kioctx *);
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-
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/* aio_setup
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* Creates the slab caches used by the aio routines, panic on
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* failure as this is done early during the boot sequence.
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@@ -68,10 +128,7 @@ static int __init aio_setup(void)
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kiocb_cachep = KMEM_CACHE(kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
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kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);
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- aio_wq = alloc_workqueue("aio", 0, 1); /* used to limit concurrency */
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- BUG_ON(!aio_wq);
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-
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- pr_debug("aio_setup: sizeof(struct page) = %d\n", (int)sizeof(struct page));
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+ pr_debug("sizeof(struct page) = %zu\n", sizeof(struct page));
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return 0;
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}
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@@ -79,28 +136,23 @@ __initcall(aio_setup);
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static void aio_free_ring(struct kioctx *ctx)
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{
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- struct aio_ring_info *info = &ctx->ring_info;
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long i;
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- for (i=0; i<info->nr_pages; i++)
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- put_page(info->ring_pages[i]);
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+ for (i = 0; i < ctx->nr_pages; i++)
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+ put_page(ctx->ring_pages[i]);
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- if (info->mmap_size) {
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- BUG_ON(ctx->mm != current->mm);
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- vm_munmap(info->mmap_base, info->mmap_size);
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- }
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+ if (ctx->mmap_size)
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+ vm_munmap(ctx->mmap_base, ctx->mmap_size);
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- if (info->ring_pages && info->ring_pages != info->internal_pages)
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- kfree(info->ring_pages);
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- info->ring_pages = NULL;
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- info->nr = 0;
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+ if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages)
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+ kfree(ctx->ring_pages);
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}
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static int aio_setup_ring(struct kioctx *ctx)
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{
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struct aio_ring *ring;
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- struct aio_ring_info *info = &ctx->ring_info;
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unsigned nr_events = ctx->max_reqs;
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+ struct mm_struct *mm = current->mm;
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unsigned long size, populate;
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int nr_pages;
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@@ -116,46 +168,44 @@ static int aio_setup_ring(struct kioctx *ctx)
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nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring)) / sizeof(struct io_event);
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- info->nr = 0;
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- info->ring_pages = info->internal_pages;
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+ ctx->nr_events = 0;
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+ ctx->ring_pages = ctx->internal_pages;
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if (nr_pages > AIO_RING_PAGES) {
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- info->ring_pages = kcalloc(nr_pages, sizeof(struct page *), GFP_KERNEL);
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- if (!info->ring_pages)
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+ ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *),
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+ GFP_KERNEL);
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+ if (!ctx->ring_pages)
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return -ENOMEM;
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}
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- info->mmap_size = nr_pages * PAGE_SIZE;
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- dprintk("attempting mmap of %lu bytes\n", info->mmap_size);
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- down_write(&ctx->mm->mmap_sem);
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- info->mmap_base = do_mmap_pgoff(NULL, 0, info->mmap_size,
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- PROT_READ|PROT_WRITE,
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- MAP_ANONYMOUS|MAP_PRIVATE, 0,
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- &populate);
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- if (IS_ERR((void *)info->mmap_base)) {
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- up_write(&ctx->mm->mmap_sem);
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- info->mmap_size = 0;
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+ ctx->mmap_size = nr_pages * PAGE_SIZE;
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+ pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size);
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+ down_write(&mm->mmap_sem);
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+ ctx->mmap_base = do_mmap_pgoff(NULL, 0, ctx->mmap_size,
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+ PROT_READ|PROT_WRITE,
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+ MAP_ANONYMOUS|MAP_PRIVATE, 0, &populate);
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+ if (IS_ERR((void *)ctx->mmap_base)) {
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+ up_write(&mm->mmap_sem);
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+ ctx->mmap_size = 0;
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aio_free_ring(ctx);
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return -EAGAIN;
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}
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- dprintk("mmap address: 0x%08lx\n", info->mmap_base);
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- info->nr_pages = get_user_pages(current, ctx->mm,
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- info->mmap_base, nr_pages,
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- 1, 0, info->ring_pages, NULL);
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- up_write(&ctx->mm->mmap_sem);
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+ pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base);
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+ ctx->nr_pages = get_user_pages(current, mm, ctx->mmap_base, nr_pages,
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+ 1, 0, ctx->ring_pages, NULL);
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+ up_write(&mm->mmap_sem);
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- if (unlikely(info->nr_pages != nr_pages)) {
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+ if (unlikely(ctx->nr_pages != nr_pages)) {
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aio_free_ring(ctx);
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return -EAGAIN;
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}
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if (populate)
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- mm_populate(info->mmap_base, populate);
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+ mm_populate(ctx->mmap_base, populate);
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- ctx->user_id = info->mmap_base;
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+ ctx->user_id = ctx->mmap_base;
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+ ctx->nr_events = nr_events; /* trusted copy */
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- info->nr = nr_events; /* trusted copy */
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-
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- ring = kmap_atomic(info->ring_pages[0]);
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+ ring = kmap_atomic(ctx->ring_pages[0]);
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ring->nr = nr_events; /* user copy */
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ring->id = ctx->user_id;
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ring->head = ring->tail = 0;
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@@ -164,72 +214,133 @@ static int aio_setup_ring(struct kioctx *ctx)
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ring->incompat_features = AIO_RING_INCOMPAT_FEATURES;
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ring->header_length = sizeof(struct aio_ring);
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kunmap_atomic(ring);
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+ flush_dcache_page(ctx->ring_pages[0]);
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return 0;
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}
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-
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-/* aio_ring_event: returns a pointer to the event at the given index from
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- * kmap_atomic(). Release the pointer with put_aio_ring_event();
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- */
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#define AIO_EVENTS_PER_PAGE (PAGE_SIZE / sizeof(struct io_event))
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#define AIO_EVENTS_FIRST_PAGE ((PAGE_SIZE - sizeof(struct aio_ring)) / sizeof(struct io_event))
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#define AIO_EVENTS_OFFSET (AIO_EVENTS_PER_PAGE - AIO_EVENTS_FIRST_PAGE)
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-#define aio_ring_event(info, nr) ({ \
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- unsigned pos = (nr) + AIO_EVENTS_OFFSET; \
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- struct io_event *__event; \
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- __event = kmap_atomic( \
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- (info)->ring_pages[pos / AIO_EVENTS_PER_PAGE]); \
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- __event += pos % AIO_EVENTS_PER_PAGE; \
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- __event; \
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-})
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-
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-#define put_aio_ring_event(event) do { \
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- struct io_event *__event = (event); \
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- (void)__event; \
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- kunmap_atomic((void *)((unsigned long)__event & PAGE_MASK)); \
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-} while(0)
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-
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-static void ctx_rcu_free(struct rcu_head *head)
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+void kiocb_set_cancel_fn(struct kiocb *req, kiocb_cancel_fn *cancel)
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+{
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+ struct kioctx *ctx = req->ki_ctx;
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+ unsigned long flags;
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+
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+ spin_lock_irqsave(&ctx->ctx_lock, flags);
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+
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+ if (!req->ki_list.next)
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+ list_add(&req->ki_list, &ctx->active_reqs);
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+
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+ req->ki_cancel = cancel;
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+
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+ spin_unlock_irqrestore(&ctx->ctx_lock, flags);
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+}
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+EXPORT_SYMBOL(kiocb_set_cancel_fn);
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+
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+static int kiocb_cancel(struct kioctx *ctx, struct kiocb *kiocb,
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+ struct io_event *res)
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+{
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+ kiocb_cancel_fn *old, *cancel;
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+ int ret = -EINVAL;
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+
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+ /*
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+ * Don't want to set kiocb->ki_cancel = KIOCB_CANCELLED unless it
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+ * actually has a cancel function, hence the cmpxchg()
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+ */
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+
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+ cancel = ACCESS_ONCE(kiocb->ki_cancel);
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+ do {
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+ if (!cancel || cancel == KIOCB_CANCELLED)
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+ return ret;
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+
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+ old = cancel;
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+ cancel = cmpxchg(&kiocb->ki_cancel, old, KIOCB_CANCELLED);
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+ } while (cancel != old);
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+
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+ atomic_inc(&kiocb->ki_users);
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+ spin_unlock_irq(&ctx->ctx_lock);
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+
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+ memset(res, 0, sizeof(*res));
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+ res->obj = (u64)(unsigned long)kiocb->ki_obj.user;
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+ res->data = kiocb->ki_user_data;
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+ ret = cancel(kiocb, res);
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+
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+ spin_lock_irq(&ctx->ctx_lock);
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+
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+ return ret;
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+}
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+
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+static void free_ioctx_rcu(struct rcu_head *head)
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{
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struct kioctx *ctx = container_of(head, struct kioctx, rcu_head);
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kmem_cache_free(kioctx_cachep, ctx);
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}
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-/* __put_ioctx
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- * Called when the last user of an aio context has gone away,
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- * and the struct needs to be freed.
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+/*
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+ * When this function runs, the kioctx has been removed from the "hash table"
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+ * and ctx->users has dropped to 0, so we know no more kiocbs can be submitted -
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+ * now it's safe to cancel any that need to be.
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*/
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-static void __put_ioctx(struct kioctx *ctx)
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+static void free_ioctx(struct kioctx *ctx)
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{
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- unsigned nr_events = ctx->max_reqs;
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- BUG_ON(ctx->reqs_active);
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+ struct aio_ring *ring;
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+ struct io_event res;
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+ struct kiocb *req;
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+ unsigned head, avail;
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- cancel_delayed_work_sync(&ctx->wq);
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- aio_free_ring(ctx);
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- mmdrop(ctx->mm);
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- ctx->mm = NULL;
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- if (nr_events) {
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- spin_lock(&aio_nr_lock);
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- BUG_ON(aio_nr - nr_events > aio_nr);
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- aio_nr -= nr_events;
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- spin_unlock(&aio_nr_lock);
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+ spin_lock_irq(&ctx->ctx_lock);
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+
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+ while (!list_empty(&ctx->active_reqs)) {
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+ req = list_first_entry(&ctx->active_reqs,
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+ struct kiocb, ki_list);
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+
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+ list_del_init(&req->ki_list);
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+ kiocb_cancel(ctx, req, &res);
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}
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- pr_debug("__put_ioctx: freeing %p\n", ctx);
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- call_rcu(&ctx->rcu_head, ctx_rcu_free);
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-}
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-static inline int try_get_ioctx(struct kioctx *kioctx)
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-{
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- return atomic_inc_not_zero(&kioctx->users);
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+ spin_unlock_irq(&ctx->ctx_lock);
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+
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+ ring = kmap_atomic(ctx->ring_pages[0]);
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+ head = ring->head;
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+ kunmap_atomic(ring);
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+
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+ while (atomic_read(&ctx->reqs_active) > 0) {
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+ wait_event(ctx->wait, head != ctx->tail);
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+
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+ avail = (head <= ctx->tail ? ctx->tail : ctx->nr_events) - head;
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+
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+ atomic_sub(avail, &ctx->reqs_active);
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+ head += avail;
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+ head %= ctx->nr_events;
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+ }
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+
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+ WARN_ON(atomic_read(&ctx->reqs_active) < 0);
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+
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+ aio_free_ring(ctx);
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+
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+ spin_lock(&aio_nr_lock);
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+ BUG_ON(aio_nr - ctx->max_reqs > aio_nr);
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+ aio_nr -= ctx->max_reqs;
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+ spin_unlock(&aio_nr_lock);
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+
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+ pr_debug("freeing %p\n", ctx);
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+
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+ /*
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+ * Here the call_rcu() is between the wait_event() for reqs_active to
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+ * hit 0, and freeing the ioctx.
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+ *
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+ * aio_complete() decrements reqs_active, but it has to touch the ioctx
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+ * after to issue a wakeup so we use rcu.
|
|
|
+ */
|
|
|
+ call_rcu(&ctx->rcu_head, free_ioctx_rcu);
|
|
|
}
|
|
|
|
|
|
-static inline void put_ioctx(struct kioctx *kioctx)
|
|
|
+static void put_ioctx(struct kioctx *ctx)
|
|
|
{
|
|
|
- BUG_ON(atomic_read(&kioctx->users) <= 0);
|
|
|
- if (unlikely(atomic_dec_and_test(&kioctx->users)))
|
|
|
- __put_ioctx(kioctx);
|
|
|
+ if (unlikely(atomic_dec_and_test(&ctx->users)))
|
|
|
+ free_ioctx(ctx);
|
|
|
}
|
|
|
|
|
|
/* ioctx_alloc
|
|
|
@@ -237,7 +348,7 @@ static inline void put_ioctx(struct kioctx *kioctx)
|
|
|
*/
|
|
|
static struct kioctx *ioctx_alloc(unsigned nr_events)
|
|
|
{
|
|
|
- struct mm_struct *mm;
|
|
|
+ struct mm_struct *mm = current->mm;
|
|
|
struct kioctx *ctx;
|
|
|
int err = -ENOMEM;
|
|
|
|
|
|
@@ -256,17 +367,15 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
|
|
|
return ERR_PTR(-ENOMEM);
|
|
|
|
|
|
ctx->max_reqs = nr_events;
|
|
|
- mm = ctx->mm = current->mm;
|
|
|
- atomic_inc(&mm->mm_count);
|
|
|
|
|
|
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;
|
|
|
@@ -286,64 +395,56 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
|
|
|
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:
|
|
|
err = -EAGAIN;
|
|
|
aio_free_ring(ctx);
|
|
|
out_freectx:
|
|
|
- mmdrop(mm);
|
|
|
kmem_cache_free(kioctx_cachep, ctx);
|
|
|
- dprintk("aio: error allocating ioctx %d\n", err);
|
|
|
+ pr_debug("error allocating ioctx %d\n", err);
|
|
|
return ERR_PTR(err);
|
|
|
}
|
|
|
|
|
|
-/* kill_ctx
|
|
|
- * 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_ctx(struct kioctx *ctx)
|
|
|
+static void kill_ioctx_work(struct work_struct *work)
|
|
|
{
|
|
|
- int (*cancel)(struct kiocb *, struct io_event *);
|
|
|
- struct task_struct *tsk = current;
|
|
|
- DECLARE_WAITQUEUE(wait, tsk);
|
|
|
- struct io_event res;
|
|
|
+ struct kioctx *ctx = container_of(work, struct kioctx, rcu_work);
|
|
|
|
|
|
- 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);
|
|
|
- }
|
|
|
- }
|
|
|
+ wake_up_all(&ctx->wait);
|
|
|
+ put_ioctx(ctx);
|
|
|
+}
|
|
|
|
|
|
- if (!ctx->reqs_active)
|
|
|
- goto out;
|
|
|
+static void kill_ioctx_rcu(struct rcu_head *head)
|
|
|
+{
|
|
|
+ struct kioctx *ctx = container_of(head, struct kioctx, rcu_head);
|
|
|
|
|
|
- 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);
|
|
|
+ INIT_WORK(&ctx->rcu_work, kill_ioctx_work);
|
|
|
+ schedule_work(&ctx->rcu_work);
|
|
|
+}
|
|
|
|
|
|
-out:
|
|
|
- spin_unlock_irq(&ctx->ctx_lock);
|
|
|
+/* 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 kioctx *ctx)
|
|
|
+{
|
|
|
+ if (!atomic_xchg(&ctx->dead, 1)) {
|
|
|
+ hlist_del_rcu(&ctx->list);
|
|
|
+ /* Between hlist_del_rcu() and dropping the initial ref */
|
|
|
+ synchronize_rcu();
|
|
|
+
|
|
|
+ /*
|
|
|
+ * We can't punt to workqueue here because put_ioctx() ->
|
|
|
+ * free_ioctx() will unmap the ringbuffer, and that has to be
|
|
|
+ * done in the original process's context. kill_ioctx_rcu/work()
|
|
|
+ * exist for exit_aio(), as in that path free_ioctx() won't do
|
|
|
+ * the unmap.
|
|
|
+ */
|
|
|
+ kill_ioctx_work(&ctx->rcu_work);
|
|
|
+ }
|
|
|
}
|
|
|
|
|
|
/* wait_on_sync_kiocb:
|
|
|
@@ -351,9 +452,9 @@ out:
|
|
|
*/
|
|
|
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();
|
|
|
}
|
|
|
@@ -362,28 +463,26 @@ ssize_t wait_on_sync_kiocb(struct kiocb *iocb)
|
|
|
}
|
|
|
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;
|
|
|
+ struct hlist_node *n;
|
|
|
|
|
|
- while (!hlist_empty(&mm->ioctx_list)) {
|
|
|
- ctx = hlist_entry(mm->ioctx_list.first, struct kioctx, list);
|
|
|
- hlist_del_rcu(&ctx->list);
|
|
|
-
|
|
|
- kill_ctx(ctx);
|
|
|
-
|
|
|
+ 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);
|
|
|
+ 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.
|
|
|
@@ -391,150 +490,53 @@ void exit_aio(struct mm_struct *mm)
|
|
|
* 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.
|
|
|
- * That way we get all munmap done to current->mm -
|
|
|
- * all other callers have ctx->mm == current->mm.
|
|
|
*/
|
|
|
- ctx->ring_info.mmap_size = 0;
|
|
|
- put_ioctx(ctx);
|
|
|
+ ctx->mmap_size = 0;
|
|
|
+
|
|
|
+ if (!atomic_xchg(&ctx->dead, 1)) {
|
|
|
+ hlist_del_rcu(&ctx->list);
|
|
|
+ call_rcu(&ctx->rcu_head, kill_ioctx_rcu);
|
|
|
+ }
|
|
|
}
|
|
|
}
|
|
|
|
|
|
/* 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 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 = NULL;
|
|
|
-
|
|
|
- return req;
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * struct kiocb's are allocated in batches to reduce the number of
|
|
|
- * times the ctx lock is acquired and released.
|
|
|
- */
|
|
|
-#define KIOCB_BATCH_SIZE 32L
|
|
|
-struct kiocb_batch {
|
|
|
- struct list_head head;
|
|
|
- long count; /* number of requests left to allocate */
|
|
|
-};
|
|
|
-
|
|
|
-static void kiocb_batch_init(struct kiocb_batch *batch, long total)
|
|
|
-{
|
|
|
- INIT_LIST_HEAD(&batch->head);
|
|
|
- batch->count = total;
|
|
|
-}
|
|
|
-
|
|
|
-static void kiocb_batch_free(struct kioctx *ctx, struct kiocb_batch *batch)
|
|
|
-{
|
|
|
- struct kiocb *req, *n;
|
|
|
-
|
|
|
- if (list_empty(&batch->head))
|
|
|
- return;
|
|
|
-
|
|
|
- spin_lock_irq(&ctx->ctx_lock);
|
|
|
- list_for_each_entry_safe(req, n, &batch->head, ki_batch) {
|
|
|
- list_del(&req->ki_batch);
|
|
|
- list_del(&req->ki_list);
|
|
|
- kmem_cache_free(kiocb_cachep, req);
|
|
|
- ctx->reqs_active--;
|
|
|
- }
|
|
|
- if (unlikely(!ctx->reqs_active && ctx->dead))
|
|
|
- wake_up_all(&ctx->wait);
|
|
|
- spin_unlock_irq(&ctx->ctx_lock);
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * Allocate a batch of kiocbs. This avoids taking and dropping the
|
|
|
- * context lock a lot during setup.
|
|
|
- */
|
|
|
-static int kiocb_batch_refill(struct kioctx *ctx, struct kiocb_batch *batch)
|
|
|
-{
|
|
|
- unsigned short allocated, to_alloc;
|
|
|
- long avail;
|
|
|
- struct kiocb *req, *n;
|
|
|
- struct aio_ring *ring;
|
|
|
-
|
|
|
- to_alloc = min(batch->count, KIOCB_BATCH_SIZE);
|
|
|
- for (allocated = 0; allocated < to_alloc; allocated++) {
|
|
|
- req = __aio_get_req(ctx);
|
|
|
- if (!req)
|
|
|
- /* allocation failed, go with what we've got */
|
|
|
- break;
|
|
|
- list_add(&req->ki_batch, &batch->head);
|
|
|
- }
|
|
|
-
|
|
|
- if (allocated == 0)
|
|
|
- goto out;
|
|
|
-
|
|
|
- spin_lock_irq(&ctx->ctx_lock);
|
|
|
- ring = kmap_atomic(ctx->ring_info.ring_pages[0]);
|
|
|
-
|
|
|
- avail = aio_ring_avail(&ctx->ring_info, ring) - ctx->reqs_active;
|
|
|
- BUG_ON(avail < 0);
|
|
|
- if (avail < allocated) {
|
|
|
- /* Trim back the number of requests. */
|
|
|
- list_for_each_entry_safe(req, n, &batch->head, ki_batch) {
|
|
|
- list_del(&req->ki_batch);
|
|
|
- kmem_cache_free(kiocb_cachep, req);
|
|
|
- if (--allocated <= avail)
|
|
|
- break;
|
|
|
- }
|
|
|
- }
|
|
|
-
|
|
|
- batch->count -= allocated;
|
|
|
- list_for_each_entry(req, &batch->head, ki_batch) {
|
|
|
- list_add(&req->ki_list, &ctx->active_reqs);
|
|
|
- ctx->reqs_active++;
|
|
|
- }
|
|
|
+ if (atomic_inc_return(&ctx->reqs_active) > ctx->nr_events - 1)
|
|
|
+ goto out_put;
|
|
|
|
|
|
- kunmap_atomic(ring);
|
|
|
- spin_unlock_irq(&ctx->ctx_lock);
|
|
|
-
|
|
|
-out:
|
|
|
- return allocated;
|
|
|
-}
|
|
|
+ req = kmem_cache_alloc(kiocb_cachep, GFP_KERNEL|__GFP_ZERO);
|
|
|
+ if (unlikely(!req))
|
|
|
+ goto out_put;
|
|
|
|
|
|
-static inline struct kiocb *aio_get_req(struct kioctx *ctx,
|
|
|
- struct kiocb_batch *batch)
|
|
|
-{
|
|
|
- struct kiocb *req;
|
|
|
+ atomic_set(&req->ki_users, 2);
|
|
|
+ req->ki_ctx = ctx;
|
|
|
|
|
|
- if (list_empty(&batch->head))
|
|
|
- if (kiocb_batch_refill(ctx, batch) == 0)
|
|
|
- return NULL;
|
|
|
- req = list_first_entry(&batch->head, struct kiocb, ki_batch);
|
|
|
- list_del(&req->ki_batch);
|
|
|
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 (req->ki_filp)
|
|
|
+ fput(req->ki_filp);
|
|
|
if (req->ki_eventfd != NULL)
|
|
|
eventfd_ctx_put(req->ki_eventfd);
|
|
|
if (req->ki_dtor)
|
|
|
@@ -542,48 +544,12 @@ static inline void really_put_req(struct kioctx *ctx, struct kiocb *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_all(&ctx->wait);
|
|
|
}
|
|
|
|
|
|
-/* __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)
|
|
|
+void aio_put_req(struct kiocb *req)
|
|
|
{
|
|
|
- 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--;
|
|
|
- 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;
|
|
|
-
|
|
|
- fput(req->ki_filp);
|
|
|
- req->ki_filp = NULL;
|
|
|
- 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;
|
|
|
+ if (atomic_dec_and_test(&req->ki_users))
|
|
|
+ kiocb_free(req);
|
|
|
}
|
|
|
EXPORT_SYMBOL(aio_put_req);
|
|
|
|
|
|
@@ -595,13 +561,8 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id)
|
|
|
rcu_read_lock();
|
|
|
|
|
|
hlist_for_each_entry_rcu(ctx, &mm->ioctx_list, list) {
|
|
|
- /*
|
|
|
- * RCU protects us against accessing freed memory but
|
|
|
- * we have to be careful not to get a reference when the
|
|
|
- * reference count already dropped to 0 (ctx->dead test
|
|
|
- * is unreliable because of races).
|
|
|
- */
|
|
|
- if (ctx->user_id == ctx_id && !ctx->dead && try_get_ioctx(ctx)){
|
|
|
+ if (ctx->user_id == ctx_id) {
|
|
|
+ atomic_inc(&ctx->users);
|
|
|
ret = ctx;
|
|
|
break;
|
|
|
}
|
|
|
@@ -611,295 +572,16 @@ static struct kioctx *lookup_ioctx(unsigned long ctx_id)
|
|
|
return ret;
|
|
|
}
|
|
|
|
|
|
-/*
|
|
|
- * 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) {
|
|
|
- /*
|
|
|
- * 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(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_all_iocbs:
|
|
|
- * Process all pending retries queued on the ioctx
|
|
|
- * run list, and keep running them until the list
|
|
|
- * stays empty.
|
|
|
- * Assumes it is operating within the aio issuer's mm context.
|
|
|
- */
|
|
|
-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; no point using non-zero delay
|
|
|
- */
|
|
|
- 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;
|
|
|
-
|
|
|
- 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);
|
|
|
-}
|
|
|
-
|
|
|
-/*
|
|
|
- * kick_iocb:
|
|
|
- * Called typically from a wait queue callback context
|
|
|
- * 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)
|
|
|
-{
|
|
|
- /* 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;
|
|
|
- }
|
|
|
-
|
|
|
- try_queue_kicked_iocb(iocb);
|
|
|
-}
|
|
|
-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:
|
|
|
@@ -909,61 +591,81 @@ int aio_complete(struct kiocb *iocb, long res, long res2)
|
|
|
* - 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;
|
|
|
}
|
|
|
|
|
|
- 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.
|
|
|
+ /*
|
|
|
+ * Take rcu_read_lock() in case the kioctx is being destroyed, as we
|
|
|
+ * need to issue a wakeup after decrementing reqs_active.
|
|
|
*/
|
|
|
- spin_lock_irqsave(&ctx->ctx_lock, flags);
|
|
|
+ rcu_read_lock();
|
|
|
|
|
|
- if (iocb->ki_run_list.prev && !list_empty(&iocb->ki_run_list))
|
|
|
- list_del_init(&iocb->ki_run_list);
|
|
|
+ if (iocb->ki_list.next) {
|
|
|
+ unsigned long flags;
|
|
|
+
|
|
|
+ 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;
|
|
|
+ }
|
|
|
|
|
|
- ring = kmap_atomic(info->ring_pages[0]);
|
|
|
+ /*
|
|
|
+ * 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);
|
|
|
|
|
|
- tail = info->tail;
|
|
|
- event = aio_ring_event(info, tail);
|
|
|
- if (++tail >= info->nr)
|
|
|
+ tail = ctx->tail;
|
|
|
+ pos = tail + AIO_EVENTS_OFFSET;
|
|
|
+
|
|
|
+ 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;
|
|
|
- ring->tail = tail;
|
|
|
+ ctx->tail = tail;
|
|
|
|
|
|
- put_aio_ring_event(event);
|
|
|
+ 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);
|
|
|
|
|
|
- pr_debug("added to ring %p at [%lu]\n", iocb, tail);
|
|
|
+ pr_debug("added to ring %p at [%u]\n", iocb, tail);
|
|
|
|
|
|
/*
|
|
|
* Check if the user asked us to deliver the result through an
|
|
|
@@ -975,7 +677,7 @@ int aio_complete(struct kiocb *iocb, long res, long res2)
|
|
|
|
|
|
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
|
|
|
@@ -988,233 +690,133 @@ put_rq:
|
|
|
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;
|
|
|
-
|
|
|
- ring = kmap_atomic(info->ring_pages[0]);
|
|
|
- dprintk("in aio_read_evt h%lu t%lu m%lu\n",
|
|
|
- (unsigned long)ring->head, (unsigned long)ring->tail,
|
|
|
- (unsigned long)ring->nr);
|
|
|
-
|
|
|
- if (ring->head == ring->tail)
|
|
|
- goto out;
|
|
|
+ unsigned head, pos;
|
|
|
+ long ret = 0;
|
|
|
+ int copy_ret;
|
|
|
|
|
|
- spin_lock(&info->ring_lock);
|
|
|
-
|
|
|
- head = ring->head % info->nr;
|
|
|
- if (head != ring->tail) {
|
|
|
- struct io_event *evp = aio_ring_event(info, head);
|
|
|
- *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);
|
|
|
- }
|
|
|
- spin_unlock(&info->ring_lock);
|
|
|
+ mutex_lock(&ctx->ring_lock);
|
|
|
|
|
|
-out:
|
|
|
- dprintk("leaving aio_read_evt: %d h%lu t%lu\n", ret,
|
|
|
- (unsigned long)ring->head, (unsigned long)ring->tail);
|
|
|
+ ring = kmap_atomic(ctx->ring_pages[0]);
|
|
|
+ head = ring->head;
|
|
|
kunmap_atomic(ring);
|
|
|
- return ret;
|
|
|
-}
|
|
|
|
|
|
-struct aio_timeout {
|
|
|
- struct timer_list timer;
|
|
|
- int timed_out;
|
|
|
- struct task_struct *p;
|
|
|
-};
|
|
|
+ pr_debug("h%u t%u m%u\n", head, ctx->tail, ctx->nr_events);
|
|
|
|
|
|
-static void timeout_func(unsigned long data)
|
|
|
-{
|
|
|
- struct aio_timeout *to = (struct aio_timeout *)data;
|
|
|
+ if (head == ctx->tail)
|
|
|
+ goto out;
|
|
|
|
|
|
- to->timed_out = 1;
|
|
|
- wake_up_process(to->p);
|
|
|
-}
|
|
|
+ while (ret < nr) {
|
|
|
+ long avail;
|
|
|
+ struct io_event *ev;
|
|
|
+ struct page *page;
|
|
|
|
|
|
-static inline void init_timeout(struct aio_timeout *to)
|
|
|
-{
|
|
|
- setup_timer_on_stack(&to->timer, timeout_func, (unsigned long) to);
|
|
|
- to->timed_out = 0;
|
|
|
- to->p = current;
|
|
|
-}
|
|
|
+ avail = (head <= ctx->tail ? ctx->tail : ctx->nr_events) - head;
|
|
|
+ if (head == ctx->tail)
|
|
|
+ break;
|
|
|
|
|
|
-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;
|
|
|
-}
|
|
|
+ avail = min(avail, nr - ret);
|
|
|
+ avail = min_t(long, avail, AIO_EVENTS_PER_PAGE -
|
|
|
+ ((head + AIO_EVENTS_OFFSET) % AIO_EVENTS_PER_PAGE));
|
|
|
|
|
|
-static inline void clear_timeout(struct aio_timeout *to)
|
|
|
-{
|
|
|
- del_singleshot_timer_sync(&to->timer);
|
|
|
-}
|
|
|
+ pos = head + AIO_EVENTS_OFFSET;
|
|
|
+ page = ctx->ring_pages[pos / AIO_EVENTS_PER_PAGE];
|
|
|
+ pos %= AIO_EVENTS_PER_PAGE;
|
|
|
|
|
|
-static int 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);
|
|
|
+ ev = kmap(page);
|
|
|
+ copy_ret = copy_to_user(event + ret, ev + pos,
|
|
|
+ sizeof(*ev) * avail);
|
|
|
+ kunmap(page);
|
|
|
|
|
|
- /* 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;
|
|
|
+ if (unlikely(copy_ret)) {
|
|
|
+ ret = -EFAULT;
|
|
|
+ goto out;
|
|
|
}
|
|
|
- ret = 0;
|
|
|
|
|
|
- /* Good, event copied to userland, update counts. */
|
|
|
- event ++;
|
|
|
- i ++;
|
|
|
+ ret += avail;
|
|
|
+ head += avail;
|
|
|
+ head %= ctx->nr_events;
|
|
|
}
|
|
|
|
|
|
- if (min_nr <= i)
|
|
|
- return i;
|
|
|
- if (ret)
|
|
|
- return ret;
|
|
|
+ ring = kmap_atomic(ctx->ring_pages[0]);
|
|
|
+ ring->head = head;
|
|
|
+ kunmap_atomic(ring);
|
|
|
+ flush_dcache_page(ctx->ring_pages[0]);
|
|
|
|
|
|
- /* End fast path */
|
|
|
+ pr_debug("%li h%u t%u\n", ret, head, ctx->tail);
|
|
|
|
|
|
- /* racey check, but it gets redone */
|
|
|
- if (!retry && unlikely(!list_empty(&ctx->run_list))) {
|
|
|
- retry = 1;
|
|
|
- aio_run_all_iocbs(ctx);
|
|
|
- goto retry;
|
|
|
- }
|
|
|
+ atomic_sub(ret, &ctx->reqs_active);
|
|
|
+out:
|
|
|
+ mutex_unlock(&ctx->ring_lock);
|
|
|
|
|
|
- init_timeout(&to);
|
|
|
- if (timeout) {
|
|
|
- struct timespec ts;
|
|
|
- ret = -EFAULT;
|
|
|
- if (unlikely(copy_from_user(&ts, timeout, sizeof(ts))))
|
|
|
- goto out;
|
|
|
+ return ret;
|
|
|
+}
|
|
|
|
|
|
- set_timeout(start_jiffies, &to, &ts);
|
|
|
- }
|
|
|
+static bool aio_read_events(struct kioctx *ctx, long min_nr, long nr,
|
|
|
+ struct io_event __user *event, long *i)
|
|
|
+{
|
|
|
+ long ret = aio_read_events_ring(ctx, event + *i, nr - *i);
|
|
|
|
|
|
- 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;
|
|
|
- if (unlikely(ctx->dead)) {
|
|
|
- ret = -EINVAL;
|
|
|
- break;
|
|
|
- }
|
|
|
- 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;
|
|
|
+ if (ret > 0)
|
|
|
+ *i += ret;
|
|
|
|
|
|
- ret = -EFAULT;
|
|
|
- if (unlikely(copy_to_user(event, &ent, sizeof(ent)))) {
|
|
|
- dprintk("aio: lost an event due to EFAULT.\n");
|
|
|
- break;
|
|
|
- }
|
|
|
+ if (unlikely(atomic_read(&ctx->dead)))
|
|
|
+ ret = -EINVAL;
|
|
|
|
|
|
- /* Good, event copied to userland, update counts. */
|
|
|
- event ++;
|
|
|
- i ++;
|
|
|
- }
|
|
|
+ if (!*i)
|
|
|
+ *i = ret;
|
|
|
|
|
|
- if (timeout)
|
|
|
- clear_timeout(&to);
|
|
|
-out:
|
|
|
- destroy_timer_on_stack(&to.timer);
|
|
|
- return i ? i : ret;
|
|
|
+ return ret < 0 || *i >= min_nr;
|
|
|
}
|
|
|
|
|
|
-/* 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)
|
|
|
+static long read_events(struct kioctx *ctx, long min_nr, long nr,
|
|
|
+ struct io_event __user *event,
|
|
|
+ struct timespec __user *timeout)
|
|
|
{
|
|
|
- struct mm_struct *mm = current->mm;
|
|
|
- int was_dead;
|
|
|
+ ktime_t until = { .tv64 = KTIME_MAX };
|
|
|
+ long ret = 0;
|
|
|
|
|
|
- /* delete the entry from the list is someone else hasn't already */
|
|
|
- spin_lock(&mm->ioctx_lock);
|
|
|
- was_dead = ioctx->dead;
|
|
|
- ioctx->dead = 1;
|
|
|
- hlist_del_rcu(&ioctx->list);
|
|
|
- spin_unlock(&mm->ioctx_lock);
|
|
|
+ if (timeout) {
|
|
|
+ struct timespec ts;
|
|
|
|
|
|
- dprintk("aio_release(%p)\n", ioctx);
|
|
|
- if (likely(!was_dead))
|
|
|
- put_ioctx(ioctx); /* twice for the list */
|
|
|
+ if (unlikely(copy_from_user(&ts, timeout, sizeof(ts))))
|
|
|
+ return -EFAULT;
|
|
|
|
|
|
- kill_ctx(ioctx);
|
|
|
+ until = timespec_to_ktime(ts);
|
|
|
+ }
|
|
|
|
|
|
/*
|
|
|
- * 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.
|
|
|
+ * 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.
|
|
|
*/
|
|
|
- wake_up_all(&ioctx->wait);
|
|
|
+ wait_event_interruptible_hrtimeout(ctx->wait,
|
|
|
+ aio_read_events(ctx, min_nr, nr, event, &ret), until);
|
|
|
+
|
|
|
+ if (!ret && signal_pending(current))
|
|
|
+ ret = -EINTR;
|
|
|
+
|
|
|
+ return ret;
|
|
|
}
|
|
|
|
|
|
/* sys_io_setup:
|
|
|
@@ -1252,7 +854,7 @@ SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
|
|
|
if (!IS_ERR(ioctx)) {
|
|
|
ret = put_user(ioctx->user_id, ctxp);
|
|
|
if (ret)
|
|
|
- io_destroy(ioctx);
|
|
|
+ kill_ioctx(ioctx);
|
|
|
put_ioctx(ioctx);
|
|
|
}
|
|
|
|
|
|
@@ -1270,7 +872,7 @@ SYSCALL_DEFINE1(io_destroy, aio_context_t, ctx)
|
|
|
{
|
|
|
struct kioctx *ioctx = lookup_ioctx(ctx);
|
|
|
if (likely(NULL != ioctx)) {
|
|
|
- io_destroy(ioctx);
|
|
|
+ kill_ioctx(ioctx);
|
|
|
put_ioctx(ioctx);
|
|
|
return 0;
|
|
|
}
|
|
|
@@ -1301,30 +903,21 @@ static void aio_advance_iovec(struct kiocb *iocb, ssize_t ret)
|
|
|
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 (opcode == IOCB_CMD_PWRITEV)
|
|
|
+ if (rw == WRITE)
|
|
|
file_start_write(file);
|
|
|
do {
|
|
|
ret = rw_op(iocb, &iocb->ki_iovec[iocb->ki_cur_seg],
|
|
|
@@ -1336,9 +929,9 @@ static ssize_t aio_rw_vect_retry(struct kiocb *iocb)
|
|
|
/* 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 (opcode == IOCB_CMD_PWRITEV)
|
|
|
+ if (rw == WRITE)
|
|
|
file_end_write(file);
|
|
|
|
|
|
/* This means we must have transferred all that we could */
|
|
|
@@ -1348,81 +941,49 @@ static ssize_t aio_rw_vect_retry(struct kiocb *iocb)
|
|
|
|
|
|
/* 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, bool compat)
|
|
|
+static ssize_t aio_setup_vectored_rw(int rw, struct kiocb *kiocb, bool compat)
|
|
|
{
|
|
|
ssize_t ret;
|
|
|
|
|
|
+ kiocb->ki_nr_segs = kiocb->ki_nbytes;
|
|
|
+
|
|
|
#ifdef CONFIG_COMPAT
|
|
|
if (compat)
|
|
|
- ret = compat_rw_copy_check_uvector(type,
|
|
|
+ ret = compat_rw_copy_check_uvector(rw,
|
|
|
(struct compat_iovec __user *)kiocb->ki_buf,
|
|
|
- kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec,
|
|
|
+ kiocb->ki_nr_segs, 1, &kiocb->ki_inline_vec,
|
|
|
&kiocb->ki_iovec);
|
|
|
else
|
|
|
#endif
|
|
|
- ret = rw_copy_check_uvector(type,
|
|
|
+ ret = rw_copy_check_uvector(rw,
|
|
|
(struct iovec __user *)kiocb->ki_buf,
|
|
|
- kiocb->ki_nbytes, 1, &kiocb->ki_inline_vec,
|
|
|
+ kiocb->ki_nr_segs, 1, &kiocb->ki_inline_vec,
|
|
|
&kiocb->ki_iovec);
|
|
|
if (ret < 0)
|
|
|
- goto out;
|
|
|
-
|
|
|
- ret = rw_verify_area(type, kiocb->ki_filp, &kiocb->ki_pos, ret);
|
|
|
- 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(int type, struct file * file, struct kiocb *kiocb)
|
|
|
+static ssize_t aio_setup_single_vector(int rw, struct kiocb *kiocb)
|
|
|
{
|
|
|
- int bytes;
|
|
|
-
|
|
|
- bytes = rw_verify_area(type, file, &kiocb->ki_pos, kiocb->ki_left);
|
|
|
- if (bytes < 0)
|
|
|
- return bytes;
|
|
|
+ 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 = bytes;
|
|
|
+ kiocb->ki_iovec->iov_len = kiocb->ki_nbytes;
|
|
|
kiocb->ki_nr_segs = 1;
|
|
|
- kiocb->ki_cur_seg = 0;
|
|
|
return 0;
|
|
|
}
|
|
|
|
|
|
@@ -1431,96 +992,95 @@ static ssize_t aio_setup_single_vector(int type, struct file * file, struct kioc
|
|
|
* 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, bool compat)
|
|
|
+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 = aio_setup_single_vector(READ, file, 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 = aio_setup_single_vector(WRITE, file, 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 = aio_setup_vectored_rw(READ, kiocb, compat);
|
|
|
- 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 = aio_setup_vectored_rw(WRITE, kiocb, compat);
|
|
|
+ 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;
|
|
|
}
|
|
|
|
|
|
static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
|
|
|
- struct iocb *iocb, struct kiocb_batch *batch,
|
|
|
- bool compat)
|
|
|
+ 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;
|
|
|
}
|
|
|
|
|
|
@@ -1534,16 +1094,16 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
|
|
|
return -EINVAL;
|
|
|
}
|
|
|
|
|
|
- file = fget(iocb->aio_fildes);
|
|
|
- if (unlikely(!file))
|
|
|
- return -EBADF;
|
|
|
-
|
|
|
- req = aio_get_req(ctx, batch); /* 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
|
|
|
@@ -1559,9 +1119,9 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
|
|
|
}
|
|
|
}
|
|
|
|
|
|
- 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;
|
|
|
}
|
|
|
|
|
|
@@ -1573,41 +1133,14 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
|
|
|
req->ki_left = req->ki_nbytes = iocb->aio_nbytes;
|
|
|
req->ki_opcode = iocb->aio_lio_opcode;
|
|
|
|
|
|
- ret = aio_setup_iocb(req, compat);
|
|
|
-
|
|
|
+ ret = aio_run_iocb(req, compat);
|
|
|
if (ret)
|
|
|
goto out_put_req;
|
|
|
|
|
|
- spin_lock_irq(&ctx->ctx_lock);
|
|
|
- /*
|
|
|
- * We could have raced with io_destroy() and are currently holding a
|
|
|
- * reference to ctx which should be destroyed. We cannot submit IO
|
|
|
- * since ctx gets freed as soon as io_submit() puts its reference. The
|
|
|
- * check here is reliable: io_destroy() sets ctx->dead before waiting
|
|
|
- * for outstanding IO and the barrier between these two is realized by
|
|
|
- * unlock of mm->ioctx_lock and lock of ctx->ctx_lock. Analogously we
|
|
|
- * increment ctx->reqs_active before checking for ctx->dead and the
|
|
|
- * barrier is realized by unlock and lock of ctx->ctx_lock. Thus if we
|
|
|
- * don't see ctx->dead set here, io_destroy() waits for our IO to
|
|
|
- * finish.
|
|
|
- */
|
|
|
- if (ctx->dead) {
|
|
|
- spin_unlock_irq(&ctx->ctx_lock);
|
|
|
- ret = -EINVAL;
|
|
|
- goto out_put_req;
|
|
|
- }
|
|
|
- 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;
|
|
|
@@ -1620,7 +1153,6 @@ long do_io_submit(aio_context_t ctx_id, long nr,
|
|
|
long ret = 0;
|
|
|
int i = 0;
|
|
|
struct blk_plug plug;
|
|
|
- struct kiocb_batch batch;
|
|
|
|
|
|
if (unlikely(nr < 0))
|
|
|
return -EINVAL;
|
|
|
@@ -1633,12 +1165,10 @@ long do_io_submit(aio_context_t ctx_id, long nr,
|
|
|
|
|
|
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;
|
|
|
}
|
|
|
|
|
|
- kiocb_batch_init(&batch, nr);
|
|
|
-
|
|
|
blk_start_plug(&plug);
|
|
|
|
|
|
/*
|
|
|
@@ -1659,13 +1189,12 @@ long do_io_submit(aio_context_t ctx_id, long nr,
|
|
|
break;
|
|
|
}
|
|
|
|
|
|
- ret = io_submit_one(ctx, user_iocb, &tmp, &batch, compat);
|
|
|
+ ret = io_submit_one(ctx, user_iocb, &tmp, compat);
|
|
|
if (ret)
|
|
|
break;
|
|
|
}
|
|
|
blk_finish_plug(&plug);
|
|
|
|
|
|
- kiocb_batch_free(ctx, &batch);
|
|
|
put_ioctx(ctx);
|
|
|
return i ? i : ret;
|
|
|
}
|
|
|
@@ -1698,10 +1227,13 @@ static struct kiocb *lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb,
|
|
|
|
|
|
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;
|
|
|
@@ -1720,7 +1252,7 @@ static struct kiocb *lookup_kiocb(struct kioctx *ctx, struct iocb __user *iocb,
|
|
|
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;
|
|
|
@@ -1735,32 +1267,22 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
|
|
|
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);
|
|
|
|
Linus Torvalds