[lvm-devel] [PATCH V2 2/2] master - thin: Add lowwatermark parameter to pool creation

[M. Mohan Kumar]

From: "M. Mohan Kumar" <mohan at in.ibm.com>

Add --lowwatermark parameter to thin-pool creation. It enables sending
dmevent when the number of free blocks in the pool reaches below this
number.

Signed-off-by: M. Mohan Kumar <mohan at in.ibm.com>
---
 tools/args.h      | 1 +
 tools/commands.h  | 6 ++++--
 tools/lvconvert.c | 1 +
 tools/lvcreate.c  | 7 ++++++-
 tools/toollib.c   | 4 ++++
 tools/toollib.h   | 1 +
 6 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/tools/args.h b/tools/args.h
index d4d6c40..93657cc 100644
--- a/tools/args.h
+++ b/tools/args.h
@@ -77,6 +77,7 @@ arg(force_long_ARG, '\0', "force", NULL, ARG_COUNTABLE)
 arg(stripes_long_ARG, '\0', "stripes", int_arg, 0)
 arg(sysinit_ARG, '\0', "sysinit", NULL, 0)
 arg(thinpool_ARG, '\0', "thinpool", string_arg, 0)
+arg(lowwatermark_ARG, '\0', "lowwatermark", int_arg, 0)
 
 /* Allow some variations */
 arg(resizable_ARG, '\0', "resizable", yes_no_arg, 0)
diff --git a/tools/commands.h b/tools/commands.h
index 986539e..f3b86b0 100644
--- a/tools/commands.h
+++ b/tools/commands.h
@@ -185,7 +185,8 @@ xx(lvcreate,
    "\t[-r|--readahead ReadAheadSectors|auto|none]\n"
    "\t[-R|--regionsize MirrorLogRegionSize]\n"
    "\t[-T|--thin  [-c|--chunksize  ChunkSize]\n"
-   "\t  [--discards {ignore|nopassdown|passdown}]\n"
+   "\t  [--discards {ignore|nopassdown|passdown}] \n"
+   "\t  [--lowwatermark low_water_mark thresold] \n"
    "\t  [--poolmetadatasize MetadataSize[bBsSkKmMgG]]]\n"
    "\t[--thinpool ThinPoolLogicalVolume{Name|Path}]\n"
    "\t[-t|--test]\n"
@@ -232,7 +233,8 @@ xx(lvcreate,
    monitor_ARG, name_ARG, nosync_ARG, noudevsync_ARG, permission_ARG,
    persistent_ARG, readahead_ARG, regionsize_ARG, size_ARG, snapshot_ARG,
    stripes_ARG, stripesize_ARG, test_ARG, thin_ARG, thinpool_ARG, type_ARG,
-   virtualoriginsize_ARG, poolmetadatasize_ARG, virtualsize_ARG, zero_ARG)
+   virtualoriginsize_ARG, poolmetadatasize_ARG, virtualsize_ARG, zero_ARG,
+   lowwatermark_ARG)
 
 xx(lvdisplay,
    "Display information about a logical volume",
diff --git a/tools/lvconvert.c b/tools/lvconvert.c
index 5bda00f..9c0ed99 100644
--- a/tools/lvconvert.c
+++ b/tools/lvconvert.c
@@ -352,6 +352,7 @@ static int _read_params(struct lvconvert_params *lp, struct cmd_context *cmd,
 				     &lp->chunk_size,
 				     &lp->discards,
 				     &lp->poolmetadata_size,
+				     NULL,
 				     &lp->zero))
 			return_0;
 
diff --git a/tools/lvcreate.c b/tools/lvcreate.c
index 78292f7..41358f8 100644
--- a/tools/lvcreate.c
+++ b/tools/lvcreate.c
@@ -799,7 +799,8 @@ static int _lvcreate_params(struct lvcreate_params *lp,
 	    !get_stripe_params(cmd, &lp->stripes, &lp->stripe_size) ||
 	    (lp->create_thin_pool &&
 	     !get_pool_params(cmd, &lp->chunk_size, &lp->discards,
-			      &lp->poolmetadatasize, &lp->zero)) ||
+			      &lp->poolmetadatasize, &lp->low_water_mark,
+			      &lp->zero)) ||
 	    !_read_mirror_params(lp, cmd) ||
 	    !_read_raid_params(lp, cmd))
 		return_0;
@@ -926,6 +927,10 @@ static int _check_thin_parameters(struct volume_group *vg, struct lvcreate_param
 			log_error("--zero may only be specified when allocating the thin pool.");
 			return 0;
 		}
+		if (arg_count(vg->cmd, lowwatermark_ARG)) {
+			log_error("--lowwatermark may only be specified when allocating the thin pool.");
+			return 0;
+		}
 	}
 
 	if (lp->create_thin_pool && lp->pool) {
diff --git a/tools/toollib.c b/tools/toollib.c
index 669d772..798d112 100644
--- a/tools/toollib.c
+++ b/tools/toollib.c
@@ -1525,6 +1525,7 @@ int get_pool_params(struct cmd_context *cmd,
 		    uint32_t *chunk_size,
 		    thin_discards_t *discards,
 		    uint64_t *pool_metadata_size,
+		    uint64_t *lowwatermark,
 		    int *zero)
 {
 	const char *dstr;
@@ -1577,6 +1578,9 @@ int get_pool_params(struct cmd_context *cmd,
 	}
 	*pool_metadata_size = arg_uint64_value(cmd, poolmetadatasize_ARG, UINT64_C(0));
 
+	if (lowwatermark)
+		*lowwatermark = arg_uint64_value(cmd, lowwatermark_ARG, UINT64_C(0));
+
 	return 1;
 }
 
diff --git a/tools/toollib.h b/tools/toollib.h
index 80c01fd..1b7a03e 100644
--- a/tools/toollib.h
+++ b/tools/toollib.h
@@ -115,6 +115,7 @@ int get_pool_params(struct cmd_context *cmd,
 		    uint32_t *chunk_size,
 		    thin_discards_t *discards,
 		    uint64_t *pool_metadata_size,
+		    uint64_t *lowwatermark,
 		    int *zero);
 int update_pool_params(struct cmd_context *cmd, unsigned attr,
 		       uint32_t data_extents, uint32_t extent_size,
-- 
1.7.11.7