introduce fd_file(), convert all accessors to it.

For any changes of struct fd representation we need to
turn existing accesses to fields into calls of wrappers.
Accesses to struct fd::flags are very few (3 in linux/file.h,
1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in
explicit initializers).
	Those can be dealt with in the commit converting to
new layout; accesses to struct fd::file are too many for that.
	This commit converts (almost) all of f.file to
fd_file(f).  It's not entirely mechanical ('file' is used as
a member name more than just in struct fd) and it does not
even attempt to distinguish the uses in pointer context from
those in boolean context; the latter will be eventually turned
into a separate helper (fd_empty()).

	NOTE: mass conversion to fd_empty(), tempting as it
might be, is a bad idea; better do that piecewise in commit
that convert from fdget...() to CLASS(...).

[conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c
caught by git; fs/stat.c one got caught by git grep]
[fs/xattr.c conflict]

Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/alpha/kernel/osf_sys.c

@@ -160,10 +160,10 @@ SYSCALL_DEFINE4(osf_getdirentries, unsigned int, fd,
 		.count = count
 	};
 
-	if (!arg.file)
+	if (!fd_file(arg))
 		return -EBADF;
 
-	error = iterate_dir(arg.file, &buf.ctx);
+	error = iterate_dir(fd_file(arg), &buf.ctx);
 	if (error >= 0)
 		error = buf.error;
 	if (count != buf.count)

arch/arm/kernel/sys_oabi-compat.c

@@ -239,19 +239,19 @@ asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd,
 	struct flock64 flock;
 	long err = -EBADF;
 
-	if (!f.file)
+	if (!fd_file(f))
 		goto out;
 
 	switch (cmd) {
 	case F_GETLK64:
 	case F_OFD_GETLK:
-		err = security_file_fcntl(f.file, cmd, arg);
+		err = security_file_fcntl(fd_file(f), cmd, arg);
 		if (err)
 			break;
 		err = get_oabi_flock(&flock, argp);
 		if (err)
 			break;
-		err = fcntl_getlk64(f.file, cmd, &flock);
+		err = fcntl_getlk64(fd_file(f), cmd, &flock);
 		if (!err)
 		       err = put_oabi_flock(&flock, argp);
 		break;
@@ -259,13 +259,13 @@ asmlinkage long sys_oabi_fcntl64(unsigned int fd, unsigned int cmd,
 	case F_SETLKW64:
 	case F_OFD_SETLK:
 	case F_OFD_SETLKW:
-		err = security_file_fcntl(f.file, cmd, arg);
+		err = security_file_fcntl(fd_file(f), cmd, arg);
 		if (err)
 			break;
 		err = get_oabi_flock(&flock, argp);
 		if (err)
 			break;
-		err = fcntl_setlk64(fd, f.file, cmd, &flock);
+		err = fcntl_setlk64(fd, fd_file(f), cmd, &flock);
 		break;
 	default:
 		err = sys_fcntl64(fd, cmd, arg);

arch/powerpc/kvm/book3s_64_vio.c

@@ -118,12 +118,12 @@ long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,
 	struct fd f;
 
 	f = fdget(tablefd);
-	if (!f.file)
+	if (!fd_file(f))
 		return -EBADF;
 
 	rcu_read_lock();
 	list_for_each_entry_rcu(stt, &kvm->arch.spapr_tce_tables, list) {
-		if (stt == f.file->private_data) {
+		if (stt == fd_file(f)->private_data) {
 			found = true;
 			break;
 		}

arch/powerpc/kvm/powerpc.c

@@ -1938,11 +1938,11 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 
 		r = -EBADF;
 		f = fdget(cap->args[0]);
-		if (!f.file)
+		if (!fd_file(f))
 			break;
 
 		r = -EPERM;
-		dev = kvm_device_from_filp(f.file);
+		dev = kvm_device_from_filp(fd_file(f));
 		if (dev)
 			r = kvmppc_mpic_connect_vcpu(dev, vcpu, cap->args[1]);
 
@@ -1957,11 +1957,11 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 
 		r = -EBADF;
 		f = fdget(cap->args[0]);
-		if (!f.file)
+		if (!fd_file(f))
 			break;
 
 		r = -EPERM;
-		dev = kvm_device_from_filp(f.file);
+		dev = kvm_device_from_filp(fd_file(f));
 		if (dev) {
 			if (xics_on_xive())
 				r = kvmppc_xive_connect_vcpu(dev, vcpu, cap->args[1]);
@@ -1980,7 +1980,7 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 
 		r = -EBADF;
 		f = fdget(cap->args[0]);
-		if (!f.file)
+		if (!fd_file(f))
 			break;
 
 		r = -ENXIO;
@@ -1990,7 +1990,7 @@ static int kvm_vcpu_ioctl_enable_cap(struct kvm_vcpu *vcpu,
 		}
 
 		r = -EPERM;
-		dev = kvm_device_from_filp(f.file);
+		dev = kvm_device_from_filp(fd_file(f));
 		if (dev)
 			r = kvmppc_xive_native_connect_vcpu(dev, vcpu,
 							    cap->args[1]);

arch/powerpc/platforms/cell/spu_syscalls.c

@@ -66,8 +66,8 @@ SYSCALL_DEFINE4(spu_create, const char __user *, name, unsigned int, flags,
 	if (flags & SPU_CREATE_AFFINITY_SPU) {
 		struct fd neighbor = fdget(neighbor_fd);
 		ret = -EBADF;
-		if (neighbor.file) {
-			ret = calls->create_thread(name, flags, mode, neighbor.file);
+		if (fd_file(neighbor)) {
+			ret = calls->create_thread(name, flags, mode, fd_file(neighbor));
 			fdput(neighbor);
 		}
 	} else
@@ -89,8 +89,8 @@ SYSCALL_DEFINE3(spu_run,int, fd, __u32 __user *, unpc, __u32 __user *, ustatus)
 
 	ret = -EBADF;
 	arg = fdget(fd);
-	if (arg.file) {
-		ret = calls->spu_run(arg.file, unpc, ustatus);
+	if (fd_file(arg)) {
+		ret = calls->spu_run(fd_file(arg), unpc, ustatus);
 		fdput(arg);
 	}
 

arch/x86/kernel/cpu/sgx/main.c

@@ -895,10 +895,10 @@ int sgx_set_attribute(unsigned long *allowed_attributes,
 {
 	struct fd f = fdget(attribute_fd);
 
-	if (!f.file)
+	if (!fd_file(f))
 		return -EINVAL;
 
-	if (f.file->f_op != &sgx_provision_fops) {
+	if (fd_file(f)->f_op != &sgx_provision_fops) {
 		fdput(f);
 		return -EINVAL;
 	}

arch/x86/kvm/svm/sev.c

@@ -534,10 +534,10 @@ static int __sev_issue_cmd(int fd, int id, void *data, int *error)
 	int ret;
 
 	f = fdget(fd);
-	if (!f.file)
+	if (!fd_file(f))
 		return -EBADF;
 
-	ret = sev_issue_cmd_external_user(f.file, id, data, error);
+	ret = sev_issue_cmd_external_user(fd_file(f), id, data, error);
 
 	fdput(f);
 	return ret;
@@ -2078,15 +2078,15 @@ int sev_vm_move_enc_context_from(struct kvm *kvm, unsigned int source_fd)
 	bool charged = false;
 	int ret;
 
-	if (!f.file)
+	if (!fd_file(f))
 		return -EBADF;
 
-	if (!file_is_kvm(f.file)) {
+	if (!file_is_kvm(fd_file(f))) {
 		ret = -EBADF;
 		goto out_fput;
 	}
 
-	source_kvm = f.file->private_data;
+	source_kvm = fd_file(f)->private_data;
 	ret = sev_lock_two_vms(kvm, source_kvm);
 	if (ret)
 		goto out_fput;
@@ -2801,15 +2801,15 @@ int sev_vm_copy_enc_context_from(struct kvm *kvm, unsigned int source_fd)
 	struct kvm_sev_info *source_sev, *mirror_sev;
 	int ret;
 
-	if (!f.file)
+	if (!fd_file(f))
 		return -EBADF;
 
-	if (!file_is_kvm(f.file)) {
+	if (!file_is_kvm(fd_file(f))) {
 		ret = -EBADF;
 		goto e_source_fput;
 	}
 
-	source_kvm = f.file->private_data;
+	source_kvm = fd_file(f)->private_data;
 	ret = sev_lock_two_vms(kvm, source_kvm);
 	if (ret)
 		goto e_source_fput;

drivers/gpu/drm/amd/amdgpu/amdgpu_sched.c

@@ -43,10 +43,10 @@ static int amdgpu_sched_process_priority_override(struct amdgpu_device *adev,
 	uint32_t id;
 	int r;
 
-	if (!f.file)
+	if (!fd_file(f))
 		return -EINVAL;
 
-	r = amdgpu_file_to_fpriv(f.file, &fpriv);
+	r = amdgpu_file_to_fpriv(fd_file(f), &fpriv);
 	if (r) {
 		fdput(f);
 		return r;
@@ -72,10 +72,10 @@ static int amdgpu_sched_context_priority_override(struct amdgpu_device *adev,
 	struct amdgpu_ctx *ctx;
 	int r;
 
-	if (!f.file)
+	if (!fd_file(f))
 		return -EINVAL;
 
-	r = amdgpu_file_to_fpriv(f.file, &fpriv);
+	r = amdgpu_file_to_fpriv(fd_file(f), &fpriv);
 	if (r) {
 		fdput(f);
 		return r;

drivers/gpu/drm/drm_syncobj.c

@@ -715,16 +715,16 @@ static int drm_syncobj_fd_to_handle(struct drm_file *file_private,
 	struct fd f = fdget(fd);
 	int ret;
 
-	if (!f.file)
+	if (!fd_file(f))
 		return -EINVAL;
 
-	if (f.file->f_op != &drm_syncobj_file_fops) {
+	if (fd_file(f)->f_op != &drm_syncobj_file_fops) {
 		fdput(f);
 		return -EINVAL;
 	}
 
 	/* take a reference to put in the idr */
-	syncobj = f.file->private_data;
+	syncobj = fd_file(f)->private_data;
 	drm_syncobj_get(syncobj);
 
 	idr_preload(GFP_KERNEL);

drivers/infiniband/core/ucma.c

@@ -1624,13 +1624,13 @@ static ssize_t ucma_migrate_id(struct ucma_file *new_file,
 
 	/* Get current fd to protect against it being closed */
 	f = fdget(cmd.fd);
-	if (!f.file)
+	if (!fd_file(f))
 		return -ENOENT;
-	if (f.file->f_op != &ucma_fops) {
+	if (fd_file(f)->f_op != &ucma_fops) {
 		ret = -EINVAL;
 		goto file_put;
 	}
-	cur_file = f.file->private_data;
+	cur_file = fd_file(f)->private_data;
 
 	/* Validate current fd and prevent destruction of id. */
 	ctx = ucma_get_ctx(cur_file, cmd.id);

drivers/infiniband/core/uverbs_cmd.c

@@ -584,12 +584,12 @@ static int ib_uverbs_open_xrcd(struct uverbs_attr_bundle *attrs)
 	if (cmd.fd != -1) {
 		/* search for file descriptor */
 		f = fdget(cmd.fd);
-		if (!f.file) {
+		if (!fd_file(f)) {
 			ret = -EBADF;
 			goto err_tree_mutex_unlock;
 		}
 
-		inode = file_inode(f.file);
+		inode = file_inode(fd_file(f));
 		xrcd = find_xrcd(ibudev, inode);
 		if (!xrcd && !(cmd.oflags & O_CREAT)) {
 			/* no file descriptor. Need CREATE flag */
@@ -632,7 +632,7 @@ static int ib_uverbs_open_xrcd(struct uverbs_attr_bundle *attrs)
 		atomic_inc(&xrcd->usecnt);
 	}
 
-	if (f.file)
+	if (fd_file(f))
 		fdput(f);
 
 	mutex_unlock(&ibudev->xrcd_tree_mutex);
@@ -648,7 +648,7 @@ err:
 	uobj_alloc_abort(&obj->uobject, attrs);
 
 err_tree_mutex_unlock:
-	if (f.file)
+	if (fd_file(f))
 		fdput(f);
 
 	mutex_unlock(&ibudev->xrcd_tree_mutex);

drivers/media/mc/mc-request.c

@@ -254,12 +254,12 @@ media_request_get_by_fd(struct media_device *mdev, int request_fd)
 		return ERR_PTR(-EBADR);
 
 	f = fdget(request_fd);
-	if (!f.file)
+	if (!fd_file(f))
 		goto err_no_req_fd;
 
-	if (f.file->f_op != &request_fops)
+	if (fd_file(f)->f_op != &request_fops)
 		goto err_fput;
-	req = f.file->private_data;
+	req = fd_file(f)->private_data;
 	if (req->mdev != mdev)
 		goto err_fput;
 

drivers/media/rc/lirc_dev.c

@@ -820,20 +820,20 @@ struct rc_dev *rc_dev_get_from_fd(int fd, bool write)
 	struct lirc_fh *fh;
 	struct rc_dev *dev;
 
-	if (!f.file)
+	if (!fd_file(f))
 		return ERR_PTR(-EBADF);
 
-	if (f.file->f_op != &lirc_fops) {
+	if (fd_file(f)->f_op != &lirc_fops) {
 		fdput(f);
 		return ERR_PTR(-EINVAL);
 	}
 
-	if (write && !(f.file->f_mode & FMODE_WRITE)) {
+	if (write && !(fd_file(f)->f_mode & FMODE_WRITE)) {
 		fdput(f);
 		return ERR_PTR(-EPERM);
 	}
 
-	fh = f.file->private_data;
+	fh = fd_file(f)->private_data;
 	dev = fh->rc;
 
 	get_device(&dev->dev);

drivers/vfio/group.c

@@ -112,7 +112,7 @@ static int vfio_group_ioctl_set_container(struct vfio_group *group,
 		return -EFAULT;
 
 	f = fdget(fd);
-	if (!f.file)
+	if (!fd_file(f))
 		return -EBADF;
 
 	mutex_lock(&group->group_lock);
@@ -125,13 +125,13 @@ static int vfio_group_ioctl_set_container(struct vfio_group *group,
 		goto out_unlock;
 	}
 
-	container = vfio_container_from_file(f.file);
+	container = vfio_container_from_file(fd_file(f));
 	if (container) {
 		ret = vfio_container_attach_group(container, group);
 		goto out_unlock;
 	}
 
-	iommufd = iommufd_ctx_from_file(f.file);
+	iommufd = iommufd_ctx_from_file(fd_file(f));
 	if (!IS_ERR(iommufd)) {
 		if (IS_ENABLED(CONFIG_VFIO_NOIOMMU) &&
 		    group->type == VFIO_NO_IOMMU)

drivers/vfio/virqfd.c

@@ -134,12 +134,12 @@ int vfio_virqfd_enable(void *opaque,
 	INIT_WORK(&virqfd->flush_inject, virqfd_flush_inject);
 
 	irqfd = fdget(fd);
-	if (!irqfd.file) {
+	if (!fd_file(irqfd)) {
 		ret = -EBADF;
 		goto err_fd;
 	}
 
-	ctx = eventfd_ctx_fileget(irqfd.file);
+	ctx = eventfd_ctx_fileget(fd_file(irqfd));
 	if (IS_ERR(ctx)) {
 		ret = PTR_ERR(ctx);
 		goto err_ctx;
@@ -171,7 +171,7 @@ int vfio_virqfd_enable(void *opaque,
 	init_waitqueue_func_entry(&virqfd->wait, virqfd_wakeup);
 	init_poll_funcptr(&virqfd->pt, virqfd_ptable_queue_proc);
 
-	events = vfs_poll(irqfd.file, &virqfd->pt);
+	events = vfs_poll(fd_file(irqfd), &virqfd->pt);
 
 	/*
 	 * Check if there was an event already pending on the eventfd

drivers/virt/acrn/irqfd.c

@@ -125,12 +125,12 @@ static int acrn_irqfd_assign(struct acrn_vm *vm, struct acrn_irqfd *args)
 	INIT_WORK(&irqfd->shutdown, hsm_irqfd_shutdown_work);
 
 	f = fdget(args->fd);
-	if (!f.file) {
+	if (!fd_file(f)) {
 		ret = -EBADF;
 		goto out;
 	}
 
-	eventfd = eventfd_ctx_fileget(f.file);
+	eventfd = eventfd_ctx_fileget(fd_file(f));
 	if (IS_ERR(eventfd)) {
 		ret = PTR_ERR(eventfd);
 		goto fail;
@@ -157,7 +157,7 @@ static int acrn_irqfd_assign(struct acrn_vm *vm, struct acrn_irqfd *args)
 	mutex_unlock(&vm->irqfds_lock);
 
 	/* Check the pending event in this stage */
-	events = vfs_poll(f.file, &irqfd->pt);
+	events = vfs_poll(fd_file(f), &irqfd->pt);
 
 	if (events & EPOLLIN)
 		acrn_irqfd_inject(irqfd);

drivers/xen/privcmd.c

@@ -959,12 +959,12 @@ static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd)
 	INIT_WORK(&kirqfd->shutdown, irqfd_shutdown);
 
 	f = fdget(irqfd->fd);
-	if (!f.file) {
+	if (!fd_file(f)) {
 		ret = -EBADF;
 		goto error_kfree;
 	}
 
-	kirqfd->eventfd = eventfd_ctx_fileget(f.file);
+	kirqfd->eventfd = eventfd_ctx_fileget(fd_file(f));
 	if (IS_ERR(kirqfd->eventfd)) {
 		ret = PTR_ERR(kirqfd->eventfd);
 		goto error_fd_put;
@@ -995,7 +995,7 @@ static int privcmd_irqfd_assign(struct privcmd_irqfd *irqfd)
 	 * Check if there was an event already pending on the eventfd before we
 	 * registered, and trigger it as if we didn't miss it.
 	 */
-	events = vfs_poll(f.file, &kirqfd->pt);
+	events = vfs_poll(fd_file(f), &kirqfd->pt);
 	if (events & EPOLLIN)
 		irqfd_inject(kirqfd);
 
@@ -1345,12 +1345,12 @@ static int privcmd_ioeventfd_assign(struct privcmd_ioeventfd *ioeventfd)
 		return -ENOMEM;
 
 	f = fdget(ioeventfd->event_fd);
-	if (!f.file) {
+	if (!fd_file(f)) {
 		ret = -EBADF;
 		goto error_kfree;
 	}
 
-	kioeventfd->eventfd = eventfd_ctx_fileget(f.file);
+	kioeventfd->eventfd = eventfd_ctx_fileget(fd_file(f));
 	fdput(f);
 
 	if (IS_ERR(kioeventfd->eventfd)) {

fs/btrfs/ioctl.c

@@ -1312,12 +1312,12 @@ static noinline int __btrfs_ioctl_snap_create(struct file *file,
 	} else {
 		struct fd src = fdget(fd);
 		struct inode *src_inode;
-		if (!src.file) {
+		if (!fd_file(src)) {
 			ret = -EINVAL;
 			goto out_drop_write;
 		}
 
-		src_inode = file_inode(src.file);
+		src_inode = file_inode(fd_file(src));
 		if (src_inode->i_sb != file_inode(file)->i_sb) {
 			btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
 				   "Snapshot src from another FS");

fs/coda/inode.c

@@ -127,9 +127,9 @@ static int coda_parse_fd(struct fs_context *fc, int fd)
 	int idx;
 
 	f = fdget(fd);
-	if (!f.file)
+	if (!fd_file(f))
 		return -EBADF;
-	inode = file_inode(f.file);
+	inode = file_inode(fd_file(f));
 	if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
 		fdput(f);
 		return invalf(fc, "code: Not coda psdev");

fs/eventfd.c

@@ -349,9 +349,9 @@ struct eventfd_ctx *eventfd_ctx_fdget(int fd)
 {
 	struct eventfd_ctx *ctx;
 	struct fd f = fdget(fd);
-	if (!f.file)
+	if (!fd_file(f))
 		return ERR_PTR(-EBADF);
-	ctx = eventfd_ctx_fileget(f.file);
+	ctx = eventfd_ctx_fileget(fd_file(f));
 	fdput(f);
 	return ctx;
 }