12506 Add support to vioblk for DISCARD operation

Reviewed by: Robert Mustacchi <rm@fingolfin.org>
Reviewed by: Hans Rosenfeld <rosenfeld@grumpf.hope-2000.org>
Approved by: Dan McDonald <danmcd@joyent.com>

2 files changed, 80 insertions, 4 deletions

diff --git a/usr/src/uts/common/sys/blkdev.h b/usr/src/uts/common/sys/blkdev.h
index 7802f06dbc..6407f7b960 100644
--- a/usr/src/uts/common/sys/blkdev.h
+++ b/usr/src/uts/common/sys/blkdev.h
@@ -23,6 +23,7 @@
  * Copyright 2016 Nexenta Systems, Inc.  All rights reserved.
  * Copyright (c) 2009, 2010, Oracle and/or its affiliates. All rights reserved.
  * Copyright 2019 Western Digital Corporation.
+ * Copyright 2020 Joyent, Inc.
  */
 
 #ifndef	_SYS_BLKDEV_H
@@ -79,8 +80,10 @@ typedef struct bd_handle *bd_handle_t;
 typedef struct bd_xfer bd_xfer_t;
 typedef struct bd_drive bd_drive_t;
 typedef struct bd_media bd_media_t;
+typedef struct bd_free_info bd_free_info_t;
 typedef struct bd_ops bd_ops_t;
 
+struct dkioc_free_list_s;
 
 struct bd_xfer {
 	/*
@@ -95,6 +98,7 @@ struct bd_xfer {
 	caddr_t			x_kaddr;
 	unsigned		x_flags;
 	unsigned		x_qnum;
+	const struct dkioc_free_list_s *x_dfl;
 };
 
 #define	BD_XFER_POLL		(1U << 0)	/* no interrupts (dump) */
@@ -119,6 +123,33 @@ struct bd_drive {
 	uint8_t			d_eui64[8];
 	/* Added at the end to maintain binary compatibility */
 	uint32_t		d_qcount;
+
+	/*
+	 * Required starting alignment for free_space requests (in logical
+	 * blocks). Must be >= 1.
+	 */
+	uint64_t		d_free_align;
+
+	/*
+	 * Maximum number of segments supported in a free space request.
+	 * 0 implies no limit.
+	 */
+	uint64_t		d_max_free_seg;
+
+	/*
+	 * Maximum number of logical blocks allowed in a free space request.
+	 * 0 implies no limit.
+	 */
+	uint64_t		d_max_free_blks;
+
+	/*
+	 * Maximum number of logical blocks to free in a single segment.
+	 * 0 implies no limit. If no limit, d_max_free_blks must also be 0.
+	 * If > 0, d_max_free_seg_blks must be <= d_max_free_blks (basically
+	 * you can't set a bigger value of d_max_free_seg_blks than
+	 * d_max_free_blks).
+	 */
+	uint64_t		d_max_free_seg_blks;
 };
 
 struct bd_media {
@@ -147,14 +178,15 @@ struct bd_media {
 #define	BD_INFO_FLAG_READ_ONLY		(1U << 2)
 
 /*
- * If the API changes and we want to bump the version, add another
- * enum value, Eg BD_OPS_VERSION_1. BD_OPS_CURRENT_VERSION should always
- * be last.
+ * When adding a new version of the bd_ops_t struct, be sure to update
+ * BD_OPS_CURRENT_VERSION
  */
 typedef enum {
 	BD_OPS_VERSION_0 = 0,
-	BD_OPS_CURRENT_VERSION
+	BD_OPS_VERSION_1 = 1,
+	BD_OPS_VERSION_2 = 2,
 } bd_version_t;
+#define	BD_OPS_CURRENT_VERSION BD_OPS_VERSION_2
 
 struct bd_ops {
 	bd_version_t	o_version;
@@ -164,6 +196,7 @@ struct bd_ops {
 	int		(*o_sync_cache)(void *, bd_xfer_t *);
 	int		(*o_read)(void *, bd_xfer_t *);
 	int		(*o_write)(void *, bd_xfer_t *);
+	int		(*o_free_space)(void *, bd_xfer_t *);
 };
 
 struct bd_errstats {
diff --git a/usr/src/uts/common/sys/dkioc_free_util.h b/usr/src/uts/common/sys/dkioc_free_util.h
index 9e83ab3bff..f61630395c 100644
--- a/usr/src/uts/common/sys/dkioc_free_util.h
+++ b/usr/src/uts/common/sys/dkioc_free_util.h
@@ -11,6 +11,7 @@
 
 /*
  * Copyright 2017 Nexenta Inc.  All rights reserved.
+ * Copyright 2020 Joyent, Inc.
  */
 
 #ifndef _SYS_DKIOC_FREE_UTIL_H
@@ -24,8 +25,50 @@ extern "C" {
 
 #define	DFL_COPYIN_MAX_EXTS	(1024 * 1024)
 
+#define	DFL_ISSYNC(dfl) (((dfl)->dfl_flags & DF_WAIT_SYNC) ? B_TRUE : B_FALSE)
+
+/*
+ * Since dkioc_free_list_t and in general DKIOCFREE use bytes to express
+ * values instead of blocks, dkioc_free_info_t uses bytes as well for
+ * consistency.
+ */
+typedef struct dkioc_free_info {
+	/* log2(block size) */
+	uint64_t	dfi_bshift;
+
+	/* Maximum number of extents in a single request. 0 == no limit */
+	uint64_t	dfi_max_ext;
+
+	/*
+	 * Maximum total number of bytes in a single request.  0 == no limit.
+	 * Must by a multiple of 1U << dfi_bshift (e.g. dfi_bshift == 9,
+	 * dfk_max_bytes must be a multiple of 512).
+	 */
+	uint64_t	dfi_max_bytes;
+
+	/*
+	 * Maximum length of an extent. 0 == same as dfi_max_bytes. If > 0,
+	 * must be a multiple of 1U << dfi_shift (the block size) and
+	 * <= dfi_max_bytes.
+	 */
+	uint64_t	dfi_max_ext_bytes;
+
+	/*
+	 * Minimum alignment for starting extent offsets in bytes
+	 * Must be > 0, and a multiple of 1U << dfi_shift.
+	 *
+	 * A possible future extention might be to also express a preferred
+	 * alignment when splitting extents.
+	 */
+	uint64_t	dfi_align;
+} dkioc_free_info_t;
+
+typedef int (*dfl_iter_fn_t)(dkioc_free_list_t *dfl, void *arg, int kmflag);
+
 int dfl_copyin(void *arg, dkioc_free_list_t **out, int ddi_flags, int kmflags);
 void dfl_free(dkioc_free_list_t *dfl);
+int dfl_iter(dkioc_free_list_t *dfl, const dkioc_free_info_t *dfi, uint64_t len,
+    dfl_iter_fn_t fn, void *arg, int kmflag);
 
 #ifdef	__cplusplus
 }