LKVS: LIBZBC Updates, CZ Calculation

Added write pointer updating because libzbc no longer supports
this functionality.

We used to have commands to set zones on a prototype drive, so I
have changed liblkvs to skip over a single or multiple conventional
zones at the beginning of the drive. This value used to be hard
coded.

In addition I had to change some testing code and scripts to support
our current prototype drives.

Signed-off-by: Adam Manzanares <[email protected]>

Author: nmtadam

tools/lkvs/src/liblkvs/liblkvs.cc

@@ -17,6 +17,7 @@
 #include <map>
 #include <vector>
 #include <cstdio>
+#include <cassert>
 
 #include <unistd.h>
 #include <endian.h>
@@ -40,9 +41,9 @@ LkvsDev::LkvsDev()
 	aligned4kBuf = (char *)memalign(ALIGNMENT, ALIGNMENT);
 	memset(aligned4kBuf, 0, ALIGNMENT);
 	numZones = 0;
-	lastZoneAlloc = 1;
 	lastReadZone = 0;
 	zDevBlockSize = 0;
+	cZones = 0;
 	zDev = NULL;
 	zDevZones = NULL;
 	zoneMeta = NULL;
@@ -54,9 +55,9 @@ LkvsDev::~LkvsDev()
 
 	// Release all of the zone specific MD buffers
 	if ( zoneMeta ) {
-		for( i = 1; i < zDevNumZones; i++){
+		for( i = cZones; i < zDevNumZones; i++){
 
-		  if( zoneMeta[i-1].mdBuf ) free( zoneMeta[i-1].mdBuf);
+		  if( zoneMeta[i-cZones].mdBuf ) free( zoneMeta[i-cZones].mdBuf);
 		}
 		free(zoneMeta);
 	}
@@ -199,14 +200,14 @@ int LkvsDev::populateMeta(int zoneIndex)
 			}
 
 			if( metaCount == 0){
-				zoneMeta[zoneIndex - 1].lastMDump = putMeta->mddump;
+				zoneMeta[zoneIndex - cZones].lastMDump = putMeta->mddump;
 			}
 
 			if( !blkCount ){
-				char *mdBufLocation = zoneMeta[zoneIndex -1].mdBuf;
-				mdBufLocation += zoneMeta[zoneIndex -1].mdEntries * MD_PB_SZ;
+				char *mdBufLocation = zoneMeta[zoneIndex - cZones].mdBuf;
+				mdBufLocation += zoneMeta[zoneIndex - cZones].mdEntries * MD_PB_SZ;
 				memcpy(mdBufLocation, putMeta, MD_PB_SZ);	
-				zoneMeta[zoneIndex -1].mdEntries++;
+				zoneMeta[zoneIndex - cZones].mdEntries++;
 			}
 			metaCount++;
 			mdPopOffset += MD_PB_SZ;
@@ -242,7 +243,7 @@ int LkvsDev::openDev(const char *dev, int flags)
 		goto out;
 	}
 
-	ret = zbc_open(targetDev.c_str(), O_RDWR | O_EXCL, &zDev);
+	ret = zbc_open(targetDev.c_str(), O_RDWR, &zDev);
 	if( ret != 0) {
 		std::cerr << "ZBC open fails" << std::endl;
 		ret = LKVS_FAILURE;
@@ -255,7 +256,22 @@ int LkvsDev::openDev(const char *dev, int flags)
 		ret = LKVS_FAILURE;
 		goto out;
 	}
-	
+
+	cZones = 0;
+	// Determine how many zones that are not sequential only
+	for( i = 0; i < zDevNumZones; i++)
+	{
+		// Make sure that the conventional zones are in a contiguous
+		// LBA range. May vary, but this works for our prototype drive.
+		if(cZones > 0 && zbc_zone_conventional(&zDevZones[i])){
+			assert(zbc_zone_conventional(&zDevZones[i-1]));
+			cZones++;
+		}else if(zbc_zone_conventional(&zDevZones[i])){
+			cZones++;
+		}
+	}
+
+	lastZoneAlloc = cZones;
 	zDevInfo = (zbc_device_info_t *)malloc(sizeof(zbc_device_info_t));
 	if(!zDevInfo){
 		std::cerr << "Lkvs Dev info allocation failed" << std::endl;
@@ -288,26 +304,26 @@ int LkvsDev::openDev(const char *dev, int flags)
 	}
 
 	// Alocate memory for zone MetaData
-	zoneMeta = (LkvsZone*)malloc(sizeof(LkvsZone) * zDevNumZones - 1);	
+	zoneMeta = (LkvsZone*)malloc(sizeof(LkvsZone) * zDevNumZones - cZones);	
 	if( !zoneMeta ) {
 		std::cerr << " ZoneMeta alloc fails" << std::endl;
 		ret = LKVS_FAILURE;
 		goto out;
 	}
-	memset(zoneMeta, 0, sizeof(LkvsZone) * zDevNumZones - 1);
+	memset(zoneMeta, 0, sizeof(LkvsZone) * (zDevNumZones - cZones));
 	// Iterate over sequential only zones and grab metadata from 
 	// zones that have data
-	for( i = 1; i < zDevNumZones; i++)
+	for( i = cZones; i < zDevNumZones; i++)
 	{
-		zoneMeta[ i - 1].mdBuf = (char *)memalign(ALIGNMENT, ALIGNMENT);
-		if( ! zoneMeta[i - 1].mdBuf ){
+		zoneMeta[ i - cZones].mdBuf = (char *)memalign(ALIGNMENT, ALIGNMENT);
+		if( ! zoneMeta[i - cZones].mdBuf ){
 			std::cerr << "MdBuf alloc fails" << std::endl;
 			ret = LKVS_FAILURE;
 			goto out;
 		}
-		memset(zoneMeta[i-1].mdBuf, 0, ALIGNMENT);
-		zoneMeta[i-1].lastMDump = 0;
-		zoneMeta[i-1].mdEntries = 0;
+		memset(zoneMeta[i- cZones].mdBuf, 0, ALIGNMENT);
+		zoneMeta[i - cZones].lastMDump = 0;
+		zoneMeta[i - cZones].mdEntries = 0;
 
 		if(zDevZones[i].zbz_write_pointer > zDevZones[i].zbz_start )
 		{
@@ -387,7 +403,8 @@ int LkvsDev::Put(const char *key, void *buf, size_t size)
 			goto out;
 		}
 	}
-	
+
+	//std::cerr << "Writing Request to Zone: " << lastZoneAlloc << std::endl;
 	curZone = &zDevZones[lastZoneAlloc];
 	// Align write pointer to 4k boundary
 	//wrPointerOffset = curZone->zbz_write_pointer % 8;
@@ -432,6 +449,7 @@ int LkvsDev::Put(const char *key, void *buf, size_t size)
 		if( curWritten != curWritesz / zDevBlockSize)  break;
 		written += curWritten * zDevBlockSize;
 		cBuf += curWritten * zDevBlockSize;
+		curZone->zbz_write_pointer += curWritten;
 	}
 	xferEnd = getTime();
 
@@ -445,15 +463,15 @@ int LkvsDev::Put(const char *key, void *buf, size_t size)
 		goto out;
 	}
 
-	mdBufLocation = zoneMeta[lastZoneAlloc -1].mdBuf;
-	if( zoneMeta[lastZoneAlloc -1].mdEntries < MD_ENTRIES_PER_BLOCK){
-		mdBufLocation += (MD_PB_SZ * zoneMeta[lastZoneAlloc -1].mdEntries);
-		zoneMeta[lastZoneAlloc -1].mdEntries++;
+	mdBufLocation = zoneMeta[lastZoneAlloc - cZones].mdBuf;
+	if( zoneMeta[lastZoneAlloc - cZones].mdEntries < MD_ENTRIES_PER_BLOCK){
+		mdBufLocation += (MD_PB_SZ * zoneMeta[lastZoneAlloc - cZones].mdEntries);
+		zoneMeta[lastZoneAlloc - cZones].mdEntries++;
 	}else{
 		//std::cerr << "MdEntries: " << curZone->mdEntries 
 		//          << ". Going to reset" << std::endl;
-		memset(zoneMeta[lastZoneAlloc - 1].mdBuf, 0, ALIGNMENT);
-		zoneMeta[lastZoneAlloc -1 ].mdEntries = 1;
+		memset(zoneMeta[lastZoneAlloc - cZones].mdBuf, 0, ALIGNMENT);
+		zoneMeta[lastZoneAlloc - cZones ].mdEntries = 1;
 	}
 
 	putMeta = (MetaData *)mdBufLocation;
@@ -463,24 +481,25 @@ int LkvsDev::Put(const char *key, void *buf, size_t size)
 	                    ((size + slack) / zDevBlockSize);
 	keyContainer.metaKeySet(putMeta);
 	// Check the logic of this across zones
-	putMeta->mddump = zoneMeta[lastZoneAlloc - 1].lastMDump;
+	putMeta->mddump = zoneMeta[lastZoneAlloc - cZones].lastMDump;
 	putMeta->magic = LKVS_META_MAGIC;
 
 	// Write the MD
 
-	written = zbc_write(zDev, curZone, zoneMeta[lastZoneAlloc - 1].mdBuf, 
+	written = zbc_write(zDev, curZone, zoneMeta[lastZoneAlloc - cZones].mdBuf, 
 	                     ALIGNMENT / zDevBlockSize );
 	if( written != ALIGNMENT / zDevBlockSize){
 		std::cerr << "MD Wanted to write: " << ALIGNMENT / zDevBlockSize 
 		          << " bytes but wrote: " 
 		          << written << " bytes." << std::endl;
 		std::cerr << strerror(errno);
-		zoneMeta[lastZoneAlloc - 1].mdEntries--;
+		zoneMeta[lastZoneAlloc - cZones].mdEntries--;
 		goto out;
 	}
+	curZone->zbz_write_pointer += written;
 	// Update last offset 
-	if( zoneMeta[lastZoneAlloc - 1 ].mdEntries == MD_ENTRIES_PER_BLOCK ){
-		zoneMeta[lastZoneAlloc - 1 ].lastMDump = 
+	if( zoneMeta[lastZoneAlloc - cZones ].mdEntries == MD_ENTRIES_PER_BLOCK ){
+		zoneMeta[lastZoneAlloc - cZones ].lastMDump = 
 		  curZone->zbz_write_pointer - ALIGNMENT / zDevBlockSize;  
 	}
 	zbc_flush(zDev);
@@ -610,7 +629,7 @@ int LkvsDev::searchForZone(size_t size){
 
 	unsigned int curZonePos;
 
-	for(curZonePos = 1; curZonePos < zDevNumZones; curZonePos++){
+	for(curZonePos = cZones; curZonePos < zDevNumZones; curZonePos++){
 		if( !reserve(curZonePos, size) ){
 			lastZoneAlloc = curZonePos;
 			return LKVS_SUCCESS;

tools/lkvs/src/liblkvs/lkvs.hpp

@@ -151,7 +151,7 @@ class LkvsDev{
 		unsigned long long devSize;
 		unsigned int numZones, lastZoneAlloc, lastReadZone; 
 		unsigned int zDevBlockSize;
-		unsigned int zDevNumZones;
+		unsigned int zDevNumZones, cZones;
 		char *aligned4kBuf;
 		LkvsZone *zoneMeta;
 

tools/lkvs/src/test/lkvsdev_test.cc

@@ -71,8 +71,6 @@ TEST_F(LkvsDevTest, Open){
 	tester = new LkvsDev();
 	// Format of ZBC drive succeeds 
 	EXPECT_EQ(LKVS_SUCCESS, tester->openDev(devPath, LKVS_FLAG_FORMAT));
-	// Open of currently open ZBC drive fails
-	EXPECT_EQ(LKVS_FAILURE, tester->openDev(devPath, 0));
 	delete tester;
 
 	tester = new LkvsDev();

tools/lkvs/src/test/zbc_reset.sh

@@ -13,5 +13,5 @@
 #
 #
 
-dd if=/dev/zero of=$LKVSDEVFILE count=1 bs=4096 oflag=sync conv=notrunc
-zbc_set_zones $LKVSDEVFILE set_sz 2097152 2097152
+sg_dd if=/dev/zero of=$LKVSDEVFILE count=4 bs=512
+zbc_reset_write_ptr $LKVSDEVFILE -1