switch generic_file_splice_read() to use of ->read_iter()

... and kill the ->splice_read() instances that can be switched to it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

4 files changed, 21 insertions, 123 deletions

diff --git a/drivers/staging/lustre/lustre/llite/file.c b/drivers/staging/lustre/lustre/llite/file.c
index 57281b9e31ff..2567b09f4cfe 100644
--- a/drivers/staging/lustre/lustre/llite/file.c
+++ b/drivers/staging/lustre/lustre/llite/file.c
@@ -1153,36 +1153,21 @@ restart:
 		int write_mutex_locked = 0;
 
 		vio->vui_fd  = LUSTRE_FPRIVATE(file);
-		vio->vui_io_subtype = args->via_io_subtype;
-
-		switch (vio->vui_io_subtype) {
-		case IO_NORMAL:
-			vio->vui_iter = args->u.normal.via_iter;
-			vio->vui_iocb = args->u.normal.via_iocb;
-			if ((iot == CIT_WRITE) &&
-			    !(vio->vui_fd->fd_flags & LL_FILE_GROUP_LOCKED)) {
-				if (mutex_lock_interruptible(&lli->
-							       lli_write_mutex)) {
-					result = -ERESTARTSYS;
-					goto out;
-				}
-				write_mutex_locked = 1;
+		vio->vui_iter = args->u.normal.via_iter;
+		vio->vui_iocb = args->u.normal.via_iocb;
+		if ((iot == CIT_WRITE) &&
+		    !(vio->vui_fd->fd_flags & LL_FILE_GROUP_LOCKED)) {
+			if (mutex_lock_interruptible(&lli->lli_write_mutex)) {
+				result = -ERESTARTSYS;
+				goto out;
 			}
-			down_read(&lli->lli_trunc_sem);
-			break;
-		case IO_SPLICE:
-			vio->u.splice.vui_pipe = args->u.splice.via_pipe;
-			vio->u.splice.vui_flags = args->u.splice.via_flags;
-			break;
-		default:
-			CERROR("Unknown IO type - %u\n", vio->vui_io_subtype);
-			LBUG();
+			write_mutex_locked = 1;
 		}
+		down_read(&lli->lli_trunc_sem);
 		ll_cl_add(file, env, io);
 		result = cl_io_loop(env, io);
 		ll_cl_remove(file, env);
-		if (args->via_io_subtype == IO_NORMAL)
-			up_read(&lli->lli_trunc_sem);
+		up_read(&lli->lli_trunc_sem);
 		if (write_mutex_locked)
 			mutex_unlock(&lli->lli_write_mutex);
 	} else {
@@ -1237,7 +1222,7 @@ static ssize_t ll_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
 	if (IS_ERR(env))
 		return PTR_ERR(env);
 
-	args = ll_env_args(env, IO_NORMAL);
+	args = ll_env_args(env);
 	args->u.normal.via_iter = to;
 	args->u.normal.via_iocb = iocb;
 
@@ -1261,7 +1246,7 @@ static ssize_t ll_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	if (IS_ERR(env))
 		return PTR_ERR(env);
 
-	args = ll_env_args(env, IO_NORMAL);
+	args = ll_env_args(env);
 	args->u.normal.via_iter = from;
 	args->u.normal.via_iocb = iocb;
 
@@ -1271,31 +1256,6 @@ static ssize_t ll_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
 	return result;
 }
 
-/*
- * Send file content (through pagecache) somewhere with helper
- */
-static ssize_t ll_file_splice_read(struct file *in_file, loff_t *ppos,
-				   struct pipe_inode_info *pipe, size_t count,
-				   unsigned int flags)
-{
-	struct lu_env      *env;
-	struct vvp_io_args *args;
-	ssize_t	     result;
-	int		 refcheck;
-
-	env = cl_env_get(&refcheck);
-	if (IS_ERR(env))
-		return PTR_ERR(env);
-
-	args = ll_env_args(env, IO_SPLICE);
-	args->u.splice.via_pipe = pipe;
-	args->u.splice.via_flags = flags;
-
-	result = ll_file_io_generic(env, args, in_file, CIT_READ, ppos, count);
-	cl_env_put(env, &refcheck);
-	return result;
-}
-
 static int ll_lov_recreate(struct inode *inode, struct ost_id *oi, u32 ost_idx)
 {
 	struct obd_export *exp = ll_i2dtexp(inode);
@@ -3173,7 +3133,7 @@ struct file_operations ll_file_operations = {
 	.release	= ll_file_release,
 	.mmap	   = ll_file_mmap,
 	.llseek	 = ll_file_seek,
-	.splice_read    = ll_file_splice_read,
+	.splice_read    = generic_file_splice_read,
 	.fsync	  = ll_fsync,
 	.flush	  = ll_flush
 };
@@ -3186,7 +3146,7 @@ struct file_operations ll_file_operations_flock = {
 	.release	= ll_file_release,
 	.mmap	   = ll_file_mmap,
 	.llseek	 = ll_file_seek,
-	.splice_read    = ll_file_splice_read,
+	.splice_read    = generic_file_splice_read,
 	.fsync	  = ll_fsync,
 	.flush	  = ll_flush,
 	.flock	  = ll_file_flock,
@@ -3202,7 +3162,7 @@ struct file_operations ll_file_operations_noflock = {
 	.release	= ll_file_release,
 	.mmap	   = ll_file_mmap,
 	.llseek	 = ll_file_seek,
-	.splice_read    = ll_file_splice_read,
+	.splice_read    = generic_file_splice_read,
 	.fsync	  = ll_fsync,
 	.flush	  = ll_flush,
 	.flock	  = ll_file_noflock,
diff --git a/drivers/staging/lustre/lustre/llite/llite_internal.h b/drivers/staging/lustre/lustre/llite/llite_internal.h
index 4d6d589a1677..0e738c8ab484 100644
--- a/drivers/staging/lustre/lustre/llite/llite_internal.h
+++ b/drivers/staging/lustre/lustre/llite/llite_internal.h
@@ -800,17 +800,11 @@ void vvp_write_complete(struct vvp_object *club, struct vvp_page *page);
  */
 struct vvp_io_args {
 	/** normal/splice */
-	enum vvp_io_subtype via_io_subtype;
-
 	union {
 		struct {
 			struct kiocb      *via_iocb;
 			struct iov_iter   *via_iter;
 		} normal;
-		struct {
-			struct pipe_inode_info  *via_pipe;
-			unsigned int       via_flags;
-		} splice;
 	} u;
 };
 
@@ -838,14 +832,9 @@ static inline struct ll_thread_info *ll_env_info(const struct lu_env *env)
 	return lti;
 }
 
-static inline struct vvp_io_args *ll_env_args(const struct lu_env *env,
-					      enum vvp_io_subtype type)
+static inline struct vvp_io_args *ll_env_args(const struct lu_env *env)
 {
-	struct vvp_io_args *via = &ll_env_info(env)->lti_args;
-
-	via->via_io_subtype = type;
-
-	return via;
+	return &ll_env_info(env)->lti_args;
 }
 
 void ll_queue_done_writing(struct inode *inode, unsigned long flags);
diff --git a/drivers/staging/lustre/lustre/llite/vvp_internal.h b/drivers/staging/lustre/lustre/llite/vvp_internal.h
index 79fc428461ed..2fa49cca701f 100644
--- a/drivers/staging/lustre/lustre/llite/vvp_internal.h
+++ b/drivers/staging/lustre/lustre/llite/vvp_internal.h
@@ -49,14 +49,6 @@ struct obd_device;
 struct obd_export;
 struct page;
 
-/* specific architecture can implement only part of this list */
-enum vvp_io_subtype {
-	/** normal IO */
-	IO_NORMAL,
-	/** io started from splice_{read|write} */
-	IO_SPLICE
-};
-
 /**
  * IO state private to IO state private to VVP layer.
  */
@@ -99,10 +91,6 @@ struct vvp_io {
 			bool		ft_flags_valid;
 		} fault;
 		struct {
-			struct pipe_inode_info	*vui_pipe;
-			unsigned int		 vui_flags;
-		} splice;
-		struct {
 			struct cl_page_list vui_queue;
 			unsigned long vui_written;
 			int vui_from;
@@ -110,8 +98,6 @@ struct vvp_io {
 		} write;
 	} u;
 
-	enum vvp_io_subtype	vui_io_subtype;
-
 	/**
 	 * Layout version when this IO is initialized
 	 */
diff --git a/drivers/staging/lustre/lustre/llite/vvp_io.c b/drivers/staging/lustre/lustre/llite/vvp_io.c
index 94916dcc6caa..48646009290d 100644
--- a/drivers/staging/lustre/lustre/llite/vvp_io.c
+++ b/drivers/staging/lustre/lustre/llite/vvp_io.c
@@ -55,18 +55,6 @@ static struct vvp_io *cl2vvp_io(const struct lu_env *env,
 }
 
 /**
- * True, if \a io is a normal io, False for splice_{read,write}
- */
-static int cl_is_normalio(const struct lu_env *env, const struct cl_io *io)
-{
-	struct vvp_io *vio = vvp_env_io(env);
-
-	LASSERT(io->ci_type == CIT_READ || io->ci_type == CIT_WRITE);
-
-	return vio->vui_io_subtype == IO_NORMAL;
-}
-
-/**
  * For swapping layout. The file's layout may have changed.
  * To avoid populating pages to a wrong stripe, we have to verify the
  * correctness of layout. It works because swapping layout processes
@@ -391,9 +379,6 @@ static int vvp_mmap_locks(const struct lu_env *env,
 
 	LASSERT(io->ci_type == CIT_READ || io->ci_type == CIT_WRITE);
 
-	if (!cl_is_normalio(env, io))
-		return 0;
-
 	if (!vio->vui_iter) /* nfs or loop back device write */
 		return 0;
 
@@ -462,15 +447,10 @@ static void vvp_io_advance(const struct lu_env *env,
 			   const struct cl_io_slice *ios,
 			   size_t nob)
 {
-	struct vvp_io    *vio = cl2vvp_io(env, ios);
-	struct cl_io     *io  = ios->cis_io;
 	struct cl_object *obj = ios->cis_io->ci_obj;
-
+	struct vvp_io	 *vio = cl2vvp_io(env, ios);
 	CLOBINVRNT(env, obj, vvp_object_invariant(obj));
 
-	if (!cl_is_normalio(env, io))
-		return;
-
 	iov_iter_reexpand(vio->vui_iter, vio->vui_tot_count  -= nob);
 }
 
@@ -479,7 +459,7 @@ static void vvp_io_update_iov(const struct lu_env *env,
 {
 	size_t size = io->u.ci_rw.crw_count;
 
-	if (!cl_is_normalio(env, io) || !vio->vui_iter)
+	if (!vio->vui_iter)
 		return;
 
 	iov_iter_truncate(vio->vui_iter, size);
@@ -716,25 +696,8 @@ static int vvp_io_read_start(const struct lu_env *env,
 
 	/* BUG: 5972 */
 	file_accessed(file);
-	switch (vio->vui_io_subtype) {
-	case IO_NORMAL:
-		LASSERT(vio->vui_iocb->ki_pos == pos);
-		result = generic_file_read_iter(vio->vui_iocb, vio->vui_iter);
-		break;
-	case IO_SPLICE:
-		result = generic_file_splice_read(file, &pos,
-						  vio->u.splice.vui_pipe, cnt,
-						  vio->u.splice.vui_flags);
-		/* LU-1109: do splice read stripe by stripe otherwise if it
-		 * may make nfsd stuck if this read occupied all internal pipe
-		 * buffers.
-		 */
-		io->ci_continue = 0;
-		break;
-	default:
-		CERROR("Wrong IO type %u\n", vio->vui_io_subtype);
-		LBUG();
-	}
+	LASSERT(vio->vui_iocb->ki_pos == pos);
+	result = generic_file_read_iter(vio->vui_iocb, vio->vui_iter);
 
 out:
 	if (result >= 0) {