#include <linux/eventfd.h>
#include <linux/blkdev.h>
#include <linux/compat.h>
+#include <linux/anon_inodes.h>
+#include <linux/migrate.h>
+#include <linux/ramfs.h>
#include <asm/kmap_types.h>
#include <asm/uaccess.h>
} ____cacheline_aligned_in_smp;
struct page *internal_pages[AIO_RING_PAGES];
+ struct file *aio_ring_file;
};
/*------ sysctl variables----*/
static void aio_free_ring(struct kioctx *ctx)
{
- long i;
+ int i;
+ struct file *aio_ring_file = ctx->aio_ring_file;
- for (i = 0; i < ctx->nr_pages; i++)
+ for (i = 0; i < ctx->nr_pages; i++) {
+ pr_debug("pid(%d) [%d] page->count=%d\n", current->pid, i,
+ page_count(ctx->ring_pages[i]));
put_page(ctx->ring_pages[i]);
+ }
if (ctx->ring_pages && ctx->ring_pages != ctx->internal_pages)
kfree(ctx->ring_pages);
+
+ if (aio_ring_file) {
+ truncate_setsize(aio_ring_file->f_inode, 0);
+ pr_debug("pid(%d) i_nlink=%u d_count=%d d_unhashed=%d i_count=%d\n",
+ current->pid, aio_ring_file->f_inode->i_nlink,
+ aio_ring_file->f_path.dentry->d_count,
+ d_unhashed(aio_ring_file->f_path.dentry),
+ atomic_read(&aio_ring_file->f_inode->i_count));
+ fput(aio_ring_file);
+ ctx->aio_ring_file = NULL;
+ }
}
+static int aio_ring_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ vma->vm_ops = &generic_file_vm_ops;
+ return 0;
+}
+
+static const struct file_operations aio_ring_fops = {
+ .mmap = aio_ring_mmap,
+};
+
+static int aio_set_page_dirty(struct page *page)
+{
+ return 0;
+}
+
+static int aio_migratepage(struct address_space *mapping, struct page *new,
+ struct page *old, enum migrate_mode mode)
+{
+ struct kioctx *ctx = mapping->private_data;
+ unsigned long flags;
+ unsigned idx = old->index;
+ int rc;
+
+ /* Writeback must be complete */
+ BUG_ON(PageWriteback(old));
+ put_page(old);
+
+ rc = migrate_page_move_mapping(mapping, new, old, NULL, mode);
+ if (rc != MIGRATEPAGE_SUCCESS) {
+ get_page(old);
+ return rc;
+ }
+
+ get_page(new);
+
+ spin_lock_irqsave(&ctx->completion_lock, flags);
+ migrate_page_copy(new, old);
+ ctx->ring_pages[idx] = new;
+ spin_unlock_irqrestore(&ctx->completion_lock, flags);
+
+ return rc;
+}
+
+static const struct address_space_operations aio_ctx_aops = {
+ .set_page_dirty = aio_set_page_dirty,
+ .migratepage = aio_migratepage,
+};
+
static int aio_setup_ring(struct kioctx *ctx)
{
struct aio_ring *ring;
struct mm_struct *mm = current->mm;
unsigned long size, populate;
int nr_pages;
+ int i;
+ struct file *file;
/* Compensate for the ring buffer's head/tail overlap entry */
nr_events += 2; /* 1 is required, 2 for good luck */
size = sizeof(struct aio_ring);
size += sizeof(struct io_event) * nr_events;
- nr_pages = (size + PAGE_SIZE-1) >> PAGE_SHIFT;
+ nr_pages = PFN_UP(size);
if (nr_pages < 0)
return -EINVAL;
- nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring)) / sizeof(struct io_event);
+ file = anon_inode_getfile_private("[aio]", &aio_ring_fops, ctx, O_RDWR);
+ if (IS_ERR(file)) {
+ ctx->aio_ring_file = NULL;
+ return -EAGAIN;
+ }
+
+ file->f_inode->i_mapping->a_ops = &aio_ctx_aops;
+ file->f_inode->i_mapping->private_data = ctx;
+ file->f_inode->i_size = PAGE_SIZE * (loff_t)nr_pages;
+
+ for (i = 0; i < nr_pages; i++) {
+ struct page *page;
+ page = find_or_create_page(file->f_inode->i_mapping,
+ i, GFP_HIGHUSER | __GFP_ZERO);
+ if (!page)
+ break;
+ pr_debug("pid(%d) page[%d]->count=%d\n",
+ current->pid, i, page_count(page));
+ SetPageUptodate(page);
+ SetPageDirty(page);
+ unlock_page(page);
+ }
+ ctx->aio_ring_file = file;
+ nr_events = (PAGE_SIZE * nr_pages - sizeof(struct aio_ring))
+ / sizeof(struct io_event);
- ctx->nr_events = 0;
ctx->ring_pages = ctx->internal_pages;
if (nr_pages > AIO_RING_PAGES) {
ctx->ring_pages = kcalloc(nr_pages, sizeof(struct page *),
ctx->mmap_size = nr_pages * PAGE_SIZE;
pr_debug("attempting mmap of %lu bytes\n", ctx->mmap_size);
+
down_write(&mm->mmap_sem);
- ctx->mmap_base = do_mmap_pgoff(NULL, 0, ctx->mmap_size,
- PROT_READ|PROT_WRITE,
- MAP_ANONYMOUS|MAP_PRIVATE, 0, &populate);
+ ctx->mmap_base = do_mmap_pgoff(ctx->aio_ring_file, 0, ctx->mmap_size,
+ PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_POPULATE, 0, &populate);
if (IS_ERR((void *)ctx->mmap_base)) {
up_write(&mm->mmap_sem);
ctx->mmap_size = 0;
aio_free_ring(ctx);
return -EAGAIN;
}
+ up_write(&mm->mmap_sem);
+
+ mm_populate(ctx->mmap_base, populate);
pr_debug("mmap address: 0x%08lx\n", ctx->mmap_base);
ctx->nr_pages = get_user_pages(current, mm, ctx->mmap_base, nr_pages,
1, 0, ctx->ring_pages, NULL);
- up_write(&mm->mmap_sem);
+ for (i = 0; i < ctx->nr_pages; i++)
+ put_page(ctx->ring_pages[i]);
if (unlikely(ctx->nr_pages != nr_pages)) {
aio_free_ring(ctx);
return -EAGAIN;
}
- if (populate)
- mm_populate(ctx->mmap_base, populate);
ctx->user_id = ctx->mmap_base;
ctx->nr_events = nr_events; /* trusted copy */
err = -EAGAIN;
aio_free_ring(ctx);
out_freectx:
+ if (ctx->aio_ring_file)
+ fput(ctx->aio_ring_file);
kmem_cache_free(kioctx_cachep, ctx);
pr_debug("error allocating ioctx %d\n", err);
return ERR_PTR(err);
projects / mirror_ubuntu-artful-kernel.git / blobdiff