1 files changed, 348 insertions, 0 deletions
diff --git a/sys/contrib/openzfs/module/os/linux/zfs/vdev_file.c b/sys/contrib/openzfs/module/os/linux/zfs/vdev_file.c
new file mode 100644
index 000000000000..a4e71ca40788
--- /dev/null
+++ b/sys/contrib/openzfs/module/os/linux/zfs/vdev_file.c
@@ -0,0 +1,348 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 2016 by Delphix. All rights reserved.
+ */
+
+#include <sys/zfs_context.h>
+#include <sys/spa.h>
+#include <sys/spa_impl.h>
+#include <sys/vdev_file.h>
+#include <sys/vdev_impl.h>
+#include <sys/vdev_trim.h>
+#include <sys/zio.h>
+#include <sys/fs/zfs.h>
+#include <sys/fm/fs/zfs.h>
+#include <sys/abd.h>
+#include <sys/fcntl.h>
+#include <sys/vnode.h>
+#include <sys/zfs_file.h>
+#ifdef _KERNEL
+#include <linux/falloc.h>
+#endif
+/*
+ * Virtual device vector for files.
+ */
+
+static taskq_t *vdev_file_taskq;
+
+static void
+vdev_file_hold(vdev_t *vd)
+{
+	ASSERT(vd->vdev_path != NULL);
+}
+
+static void
+vdev_file_rele(vdev_t *vd)
+{
+	ASSERT(vd->vdev_path != NULL);
+}
+
+static mode_t
+vdev_file_open_mode(spa_mode_t spa_mode)
+{
+	mode_t mode = 0;
+
+	if ((spa_mode & SPA_MODE_READ) && (spa_mode & SPA_MODE_WRITE)) {
+		mode = O_RDWR;
+	} else if (spa_mode & SPA_MODE_READ) {
+		mode = O_RDONLY;
+	} else if (spa_mode & SPA_MODE_WRITE) {
+		mode = O_WRONLY;
+	}
+
+	return (mode | O_LARGEFILE);
+}
+
+static int
+vdev_file_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
+    uint64_t *logical_ashift, uint64_t *physical_ashift)
+{
+	vdev_file_t *vf;
+	zfs_file_t *fp;
+	zfs_file_attr_t zfa;
+	int error;
+
+	/*
+	 * Rotational optimizations only make sense on block devices.
+	 */
+	vd->vdev_nonrot = B_TRUE;
+
+	/*
+	 * Allow TRIM on file based vdevs.  This may not always be supported,
+	 * since it depends on your kernel version and underlying filesystem
+	 * type but it is always safe to attempt.
+	 */
+	vd->vdev_has_trim = B_TRUE;
+
+	/*
+	 * Disable secure TRIM on file based vdevs.  There is no way to
+	 * request this behavior from the underlying filesystem.
+	 */
+	vd->vdev_has_securetrim = B_FALSE;
+
+	/*
+	 * We must have a pathname, and it must be absolute.
+	 */
+	if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
+		vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
+		return (SET_ERROR(EINVAL));
+	}
+
+	/*
+	 * Reopen the device if it's not currently open.  Otherwise,
+	 * just update the physical size of the device.
+	 */
+	if (vd->vdev_tsd != NULL) {
+		ASSERT(vd->vdev_reopening);
+		vf = vd->vdev_tsd;
+		goto skip_open;
+	}
+
+	vf = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_file_t), KM_SLEEP);
+
+	/*
+	 * We always open the files from the root of the global zone, even if
+	 * we're in a local zone.  If the user has gotten to this point, the
+	 * administrator has already decided that the pool should be available
+	 * to local zone users, so the underlying devices should be as well.
+	 */
+	ASSERT(vd->vdev_path != NULL && vd->vdev_path[0] == '/');
+
+	error = zfs_file_open(vd->vdev_path,
+	    vdev_file_open_mode(spa_mode(vd->vdev_spa)), 0, &fp);
+	if (error) {
+		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
+		return (error);
+	}
+
+	vf->vf_file = fp;
+
+#ifdef _KERNEL
+	/*
+	 * Make sure it's a regular file.
+	 */
+	if (zfs_file_getattr(fp, &zfa)) {
+		return (SET_ERROR(ENODEV));
+	}
+	if (!S_ISREG(zfa.zfa_mode)) {
+		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
+		return (SET_ERROR(ENODEV));
+	}
+#endif
+
+skip_open:
+
+	error =  zfs_file_getattr(vf->vf_file, &zfa);
+	if (error) {
+		vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
+		return (error);
+	}
+
+	*max_psize = *psize = zfa.zfa_size;
+	*logical_ashift = SPA_MINBLOCKSHIFT;
+	*physical_ashift = SPA_MINBLOCKSHIFT;
+
+	return (0);
+}
+
+static void
+vdev_file_close(vdev_t *vd)
+{
+	vdev_file_t *vf = vd->vdev_tsd;
+
+	if (vd->vdev_reopening || vf == NULL)
+		return;
+
+	if (vf->vf_file != NULL) {
+		(void) zfs_file_close(vf->vf_file);
+	}
+
+	vd->vdev_delayed_close = B_FALSE;
+	kmem_free(vf, sizeof (vdev_file_t));
+	vd->vdev_tsd = NULL;
+}
+
+static void
+vdev_file_io_strategy(void *arg)
+{
+	zio_t *zio = (zio_t *)arg;
+	vdev_t *vd = zio->io_vd;
+	vdev_file_t *vf = vd->vdev_tsd;
+	ssize_t resid;
+	void *buf;
+	loff_t off;
+	ssize_t size;
+	int err;
+
+	off = zio->io_offset;
+	size = zio->io_size;
+	resid = 0;
+
+	if (zio->io_type == ZIO_TYPE_READ) {
+		buf = abd_borrow_buf(zio->io_abd, zio->io_size);
+		err = zfs_file_pread(vf->vf_file, buf, size, off, &resid);
+		abd_return_buf_copy(zio->io_abd, buf, size);
+	} else {
+		buf = abd_borrow_buf_copy(zio->io_abd, zio->io_size);
+		err = zfs_file_pwrite(vf->vf_file, buf, size, off, &resid);
+		abd_return_buf(zio->io_abd, buf, size);
+	}
+	zio->io_error = err;
+	if (resid != 0 && zio->io_error == 0)
+		zio->io_error = SET_ERROR(ENOSPC);
+
+	zio_delay_interrupt(zio);
+}
+
+static void
+vdev_file_io_fsync(void *arg)
+{
+	zio_t *zio = (zio_t *)arg;
+	vdev_file_t *vf = zio->io_vd->vdev_tsd;
+
+	zio->io_error = zfs_file_fsync(vf->vf_file, O_SYNC | O_DSYNC);
+
+	zio_interrupt(zio);
+}
+
+static void
+vdev_file_io_start(zio_t *zio)
+{
+	vdev_t *vd = zio->io_vd;
+	vdev_file_t *vf = vd->vdev_tsd;
+
+	if (zio->io_type == ZIO_TYPE_IOCTL) {
+		/* XXPOLICY */
+		if (!vdev_readable(vd)) {
+			zio->io_error = SET_ERROR(ENXIO);
+			zio_interrupt(zio);
+			return;
+		}
+
+		switch (zio->io_cmd) {
+		case DKIOCFLUSHWRITECACHE:
+
+			if (zfs_nocacheflush)
+				break;
+
+			/*
+			 * We cannot safely call vfs_fsync() when PF_FSTRANS
+			 * is set in the current context.  Filesystems like
+			 * XFS include sanity checks to verify it is not
+			 * already set, see xfs_vm_writepage().  Therefore
+			 * the sync must be dispatched to a different context.
+			 */
+			if (__spl_pf_fstrans_check()) {
+				VERIFY3U(taskq_dispatch(vdev_file_taskq,
+				    vdev_file_io_fsync, zio, TQ_SLEEP), !=,
+				    TASKQID_INVALID);
+				return;
+			}
+
+			zio->io_error = zfs_file_fsync(vf->vf_file,
+			    O_SYNC | O_DSYNC);
+			break;
+		default:
+			zio->io_error = SET_ERROR(ENOTSUP);
+		}
+
+		zio_execute(zio);
+		return;
+	} else if (zio->io_type == ZIO_TYPE_TRIM) {
+		int mode = 0;
+
+		ASSERT3U(zio->io_size, !=, 0);
+#ifdef __linux__
+		mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
+#endif
+		zio->io_error = zfs_file_fallocate(vf->vf_file,
+		    mode, zio->io_offset, zio->io_size);
+		zio_execute(zio);
+		return;
+	}
+
+	zio->io_target_timestamp = zio_handle_io_delay(zio);
+
+	VERIFY3U(taskq_dispatch(vdev_file_taskq, vdev_file_io_strategy, zio,
+	    TQ_SLEEP), !=, TASKQID_INVALID);
+}
+
+/* ARGSUSED */
+static void
+vdev_file_io_done(zio_t *zio)
+{
+}
+
+vdev_ops_t vdev_file_ops = {
+	.vdev_op_open = vdev_file_open,
+	.vdev_op_close = vdev_file_close,
+	.vdev_op_asize = vdev_default_asize,
+	.vdev_op_io_start = vdev_file_io_start,
+	.vdev_op_io_done = vdev_file_io_done,
+	.vdev_op_state_change = NULL,
+	.vdev_op_need_resilver = NULL,
+	.vdev_op_hold = vdev_file_hold,
+	.vdev_op_rele = vdev_file_rele,
+	.vdev_op_remap = NULL,
+	.vdev_op_xlate = vdev_default_xlate,
+	.vdev_op_type = VDEV_TYPE_FILE,		/* name of this vdev type */
+	.vdev_op_leaf = B_TRUE			/* leaf vdev */
+};
+
+void
+vdev_file_init(void)
+{
+	vdev_file_taskq = taskq_create("z_vdev_file", MAX(boot_ncpus, 16),
+	    minclsyspri, boot_ncpus, INT_MAX, TASKQ_DYNAMIC);
+
+	VERIFY(vdev_file_taskq);
+}
+
+void
+vdev_file_fini(void)
+{
+	taskq_destroy(vdev_file_taskq);
+}
+
+/*
+ * From userland we access disks just like files.
+ */
+#ifndef _KERNEL
+
+vdev_ops_t vdev_disk_ops = {
+	.vdev_op_open = vdev_file_open,
+	.vdev_op_close = vdev_file_close,
+	.vdev_op_asize = vdev_default_asize,
+	.vdev_op_io_start = vdev_file_io_start,
+	.vdev_op_io_done = vdev_file_io_done,
+	.vdev_op_state_change = NULL,
+	.vdev_op_need_resilver = NULL,
+	.vdev_op_hold = vdev_file_hold,
+	.vdev_op_rele = vdev_file_rele,
+	.vdev_op_remap = NULL,
+	.vdev_op_xlate = vdev_default_xlate,
+	.vdev_op_type = VDEV_TYPE_DISK,		/* name of this vdev type */
+	.vdev_op_leaf = B_TRUE			/* leaf vdev */
+};
+
+#endif