Merge tag 'vfs-6.8-release.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

Pull vfs fixes from Christian Brauner:

 - Get rid of copy_mc flag in iov_iter which really only makes sense for
   the core dumping code so move it out of the generic iov iter code and
   make it coredump's problem. See the detailed commit description.

 - Revert fs/aio: Make io_cancel() generate completions again

   The initial fix here was predicated on the assumption that calling
   ki_cancel() didn't complete aio requests. However, that turned out to
   be wrong since the two drivers that actually make use of this set a
   cancellation function that performs the cancellation correctly. So
   revert this change.

 - Ensure that the test for IOCB_AIO_RW always happens before the read
   from ki_ctx.

* tag 'vfs-6.8-release.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  iov_iter: get rid of 'copy_mc' flag
  fs/aio: Check IOCB_AIO_RW before the struct aio_kiocb conversion
  Revert "fs/aio: Make io_cancel() generate completions again"

1 files changed, 22 insertions, 13 deletions

diff --git a/fs/aio.c b/fs/aio.c
index 28223f511931..9cdaa2faa536 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -589,8 +589,8 @@ static int aio_setup_ring(struct kioctx *ctx, unsigned int nr_events)
 
 void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel)
 {
-	struct aio_kiocb *req = container_of(iocb, struct aio_kiocb, rw);
-	struct kioctx *ctx = req->ki_ctx;
+	struct aio_kiocb *req;
+	struct kioctx *ctx;
 	unsigned long flags;
 
 	/*
@@ -600,9 +600,13 @@ void kiocb_set_cancel_fn(struct kiocb *iocb, kiocb_cancel_fn *cancel)
 	if (!(iocb->ki_flags & IOCB_AIO_RW))
 		return;
 
+	req = container_of(iocb, struct aio_kiocb, rw);
+
 	if (WARN_ON_ONCE(!list_empty(&req->ki_list)))
 		return;
 
+	ctx = req->ki_ctx;
+
 	spin_lock_irqsave(&ctx->ctx_lock, flags);
 	list_add_tail(&req->ki_list, &ctx->active_reqs);
 	req->ki_cancel = cancel;
@@ -2165,11 +2169,14 @@ COMPAT_SYSCALL_DEFINE3(io_submit, compat_aio_context_t, ctx_id,
 #endif
 
 /* sys_io_cancel:
- *	Attempts to cancel an iocb previously passed to io_submit(). If the
- *	operation is successfully cancelled 0 is returned. May fail with
- *	-EFAULT if any of the data structures pointed to are invalid. May
- *	fail with -EINVAL if aio_context specified by ctx_id is invalid. Will
- *	fail with -ENOSYS if not implemented.
+ *	Attempts to cancel an iocb previously passed to io_submit.  If
+ *	the operation is successfully cancelled, the resulting event is
+ *	copied into the memory pointed to by result without being placed
+ *	into the completion queue and 0 is returned.  May fail with
+ *	-EFAULT if any of the data structures pointed to are invalid.
+ *	May fail with -EINVAL if aio_context specified by ctx_id is
+ *	invalid.  May fail with -EAGAIN if the iocb specified was not
+ *	cancelled.  Will fail with -ENOSYS if not implemented.
  */
 SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
 		struct io_event __user *, result)
@@ -2200,12 +2207,14 @@ SYSCALL_DEFINE3(io_cancel, aio_context_t, ctx_id, struct iocb __user *, iocb,
 	}
 	spin_unlock_irq(&ctx->ctx_lock);
 
-	/*
-	 * The result argument is no longer used - the io_event is always
-	 * delivered via the ring buffer.
-	 */
-	if (ret == 0 && kiocb->rw.ki_flags & IOCB_AIO_RW)
-		aio_complete_rw(&kiocb->rw, -EINTR);
+	if (!ret) {
+		/*
+		 * The result argument is no longer used - the io_event is
+		 * always delivered via the ring buffer. -EINPROGRESS indicates
+		 * cancellation is progress:
+		 */
+		ret = -EINPROGRESS;
+	}
 
 	percpu_ref_put(&ctx->users);