mm: compaction: introduce sync-light migration for use by compaction

[pandora-kernel.git] / fs / aio.c

diff --git a/fs/aio.c b/fs/aio.c
index 67e4b90..3b65ee7 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -228,12 +228,6 @@ static void __put_ioctx(struct kioctx *ctx)
        call_rcu(&ctx->rcu_head, ctx_rcu_free);
 }
 
-static inline void get_ioctx(struct kioctx *kioctx)
-{
-       BUG_ON(atomic_read(&kioctx->users) <= 0);
-       atomic_inc(&kioctx->users);
-}
-
 static inline int try_get_ioctx(struct kioctx *kioctx)
 {
        return atomic_inc_not_zero(&kioctx->users);
@@ -273,7 +267,7 @@ static struct kioctx *ioctx_alloc(unsigned nr_events)
        mm = ctx->mm = current->mm;
        atomic_inc(&mm->mm_count);
 
-       atomic_set(&ctx->users, 1);
+       atomic_set(&ctx->users, 2);
        spin_lock_init(&ctx->ctx_lock);
        spin_lock_init(&ctx->ring_info.ring_lock);
        init_waitqueue_head(&ctx->wait);
@@ -609,11 +603,16 @@ static void aio_fput_routine(struct work_struct *data)
                        fput(req->ki_filp);
 
                /* Link the iocb into the context's free list */
+               rcu_read_lock();
                spin_lock_irq(&ctx->ctx_lock);
                really_put_req(ctx, req);
+               /*
+                * at that point ctx might've been killed, but actual
+                * freeing is RCU'd
+                */
                spin_unlock_irq(&ctx->ctx_lock);
+               rcu_read_unlock();
 
-               put_ioctx(ctx);
                spin_lock_irq(&fput_lock);
        }
        spin_unlock_irq(&fput_lock);
@@ -644,7 +643,6 @@ static int __aio_put_req(struct kioctx *ctx, struct kiocb *req)
         * this function will be executed w/out any aio kthread wakeup.
         */
        if (unlikely(!fput_atomic(req->ki_filp))) {
-               get_ioctx(ctx);
                spin_lock(&fput_lock);
                list_add(&req->ki_list, &fput_head);
                spin_unlock(&fput_lock);
@@ -1338,10 +1336,10 @@ SYSCALL_DEFINE2(io_setup, unsigned, nr_events, aio_context_t __user *, ctxp)
        ret = PTR_ERR(ioctx);
        if (!IS_ERR(ioctx)) {
                ret = put_user(ioctx->user_id, ctxp);
-               if (!ret)
+               if (!ret) {
+                       put_ioctx(ioctx);
                        return 0;
-
-               get_ioctx(ioctx); /* io_destroy() expects us to hold a ref */
+               }
                io_destroy(ioctx);
        }
 
@@ -1479,6 +1477,10 @@ static ssize_t aio_setup_vectored_rw(int type, struct kiocb *kiocb, bool compat)
        if (ret < 0)
                goto out;
 
+       ret = rw_verify_area(type, kiocb->ki_filp, &kiocb->ki_pos, ret);
+       if (ret < 0)
+               goto out;
+
        kiocb->ki_nr_segs = kiocb->ki_nbytes;
        kiocb->ki_cur_seg = 0;
        /* ki_nbytes/left now reflect bytes instead of segs */
@@ -1490,11 +1492,17 @@ out:
        return ret;
 }
 
-static ssize_t aio_setup_single_vector(struct kiocb *kiocb)
+static ssize_t aio_setup_single_vector(int type, struct file * file, struct kiocb *kiocb)
 {
+       int bytes;
+
+       bytes = rw_verify_area(type, file, &kiocb->ki_pos, kiocb->ki_left);
+       if (bytes < 0)
+               return bytes;
+
        kiocb->ki_iovec = &kiocb->ki_inline_vec;
        kiocb->ki_iovec->iov_base = kiocb->ki_buf;
-       kiocb->ki_iovec->iov_len = kiocb->ki_left;
+       kiocb->ki_iovec->iov_len = bytes;
        kiocb->ki_nr_segs = 1;
        kiocb->ki_cur_seg = 0;
        return 0;
@@ -1519,10 +1527,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
                if (unlikely(!access_ok(VERIFY_WRITE, kiocb->ki_buf,
                        kiocb->ki_left)))
                        break;
-               ret = security_file_permission(file, MAY_READ);
-               if (unlikely(ret))
-                       break;
-               ret = aio_setup_single_vector(kiocb);
+               ret = aio_setup_single_vector(READ, file, kiocb);
                if (ret)
                        break;
                ret = -EINVAL;
@@ -1537,10 +1542,7 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
                if (unlikely(!access_ok(VERIFY_READ, kiocb->ki_buf,
                        kiocb->ki_left)))
                        break;
-               ret = security_file_permission(file, MAY_WRITE);
-               if (unlikely(ret))
-                       break;
-               ret = aio_setup_single_vector(kiocb);
+               ret = aio_setup_single_vector(WRITE, file, kiocb);
                if (ret)
                        break;
                ret = -EINVAL;
@@ -1551,9 +1553,6 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
                ret = -EBADF;
                if (unlikely(!(file->f_mode & FMODE_READ)))
                        break;
-               ret = security_file_permission(file, MAY_READ);
-               if (unlikely(ret))
-                       break;
                ret = aio_setup_vectored_rw(READ, kiocb, compat);
                if (ret)
                        break;
@@ -1565,9 +1564,6 @@ static ssize_t aio_setup_iocb(struct kiocb *kiocb, bool compat)
                ret = -EBADF;
                if (unlikely(!(file->f_mode & FMODE_WRITE)))
                        break;
-               ret = security_file_permission(file, MAY_WRITE);
-               if (unlikely(ret))
-                       break;
                ret = aio_setup_vectored_rw(WRITE, kiocb, compat);
                if (ret)
                        break;