diff mbox series

[RFC] mdadm: Add parameter for bitmap chunk threshold

Message ID 20221006220840.275-2-jonathan.derrick@linux.dev (mailing list archive)
State Changes Requested, archived
Headers show
Series [RFC] mdadm: Add parameter for bitmap chunk threshold | expand

Commit Message

Jonathan Derrick Oct. 6, 2022, 10:08 p.m. UTC
Adds parameter to mdadm create, grow, and build similar to the delay
parameter, that specifies a chunk threshold. This value will instruct
the kernel, in-tandem with the delay timer, to flush the bitmap after
every N chunks have been dirtied. This can be used in-addition to the
delay parameter and complements it.

This requires an addition to the bitmap superblock and version increment.

Usage: -g <Number of chunks, default 0=off>

Signed-off-by: Jonathan Derrick <jonathan.derrick@linux.dev>
---
This RFC patch lacks documentation

 Build.c       |  4 ++--
 Create.c      |  8 ++++----
 Grow.c        |  8 ++++----
 ReadMe.c      | 10 +++++++---
 bitmap.c      |  7 +++++--
 bitmap.h      |  5 ++++-
 config.c      | 16 +++++++++++++++-
 mdadm.c       | 10 ++++++++++
 mdadm.h       |  5 +++--
 super-intel.c |  2 +-
 super0.c      |  3 ++-
 super1.c      |  4 +++-
 12 files changed, 60 insertions(+), 22 deletions(-)

Comments

Mariusz Tkaczyk Oct. 12, 2022, 7:17 a.m. UTC | #1
On Thu,  6 Oct 2022 16:08:38 -0600
Jonathan Derrick <jonathan.derrick@linux.dev> wrote:

> Adds parameter to mdadm create, grow, and build similar to the delay
> parameter, that specifies a chunk threshold. This value will instruct
> the kernel, in-tandem with the delay timer, to flush the bitmap after
> every N chunks have been dirtied. This can be used in-addition to the
> delay parameter and complements it.
> 
> This requires an addition to the bitmap superblock and version increment.

Hello Jonathan,
To provide that to parameter to bitmap we are updating bitmap superblock, right?
Why we need to define it in config then? I someone wants to change that
should use --grow. Am I correct?

The "threshold" is not a context property, it should be added to struct shape.
Ideally, we can extract bitmap properties to separate struct and pass it around.

And I would like to have IMSM support if that is possible.

Thanks,
Mariusz
diff mbox series

Patch

diff --git a/Build.c b/Build.c
index 8d6f6f58..9cdf9616 100644
--- a/Build.c
+++ b/Build.c
@@ -157,7 +157,7 @@  int Build(char *mddev, struct mddev_dev *devlist,
 	if (s->bitmap_file) {
 		bitmap_fd = open(s->bitmap_file, O_RDWR);
 		if (bitmap_fd < 0) {
-			int major = BITMAP_MAJOR_HI;
+			int major = c->threshold ? BITMAP_MAJOR_CHUNKFLUSH : BITMAP_MAJOR_HI;
 #if 0
 			if (s->bitmap_chunk == UnSet) {
 				pr_err("%s cannot be opened.\n", s->bitmap_file);
@@ -166,7 +166,7 @@  int Build(char *mddev, struct mddev_dev *devlist,
 #endif
 			bitmapsize = s->size >> 9; /* FIXME wrong for RAID10 */
 			if (CreateBitmap(s->bitmap_file, 1, NULL,
-					 s->bitmap_chunk, c->delay,
+					 s->bitmap_chunk, c->delay, c->threshold,
 					 s->write_behind, bitmapsize, major)) {
 				goto abort;
 			}
diff --git a/Create.c b/Create.c
index 953e7372..9ef24f82 100644
--- a/Create.c
+++ b/Create.c
@@ -143,7 +143,7 @@  int Create(struct supertype *st, char *mddev,
 	unsigned long long newsize;
 	mdu_array_info_t inf;
 
-	int major_num = BITMAP_MAJOR_HI;
+	int major_num = c->threshold ? BITMAP_MAJOR_CHUNKFLUSH : BITMAP_MAJOR_HI;
 	if (s->bitmap_file && strcmp(s->bitmap_file, "clustered") == 0) {
 		major_num = BITMAP_MAJOR_CLUSTERED;
 		if (c->nodes <= 1) {
@@ -798,8 +798,8 @@  int Create(struct supertype *st, char *mddev,
 				st->ss->name);
 			goto abort_locked;
 		}
-		if (st->ss->add_internal_bitmap(st, &s->bitmap_chunk,
-						c->delay, s->write_behind,
+		if (st->ss->add_internal_bitmap(st, &s->bitmap_chunk, c->delay,
+						c->threshold, s->write_behind,
 						bitmapsize, 1, major_num)) {
 			pr_err("Given bitmap chunk size not supported.\n");
 			goto abort_locked;
@@ -852,7 +852,7 @@  int Create(struct supertype *st, char *mddev,
 
 		st->ss->uuid_from_super(st, uuid);
 		if (CreateBitmap(s->bitmap_file, c->force, (char*)uuid, s->bitmap_chunk,
-				 c->delay, s->write_behind,
+				 c->delay, c->threshold, s->write_behind,
 				 bitmapsize,
 				 major_num)) {
 			goto abort_locked;
diff --git a/Grow.c b/Grow.c
index e362403a..5ae91138 100644
--- a/Grow.c
+++ b/Grow.c
@@ -287,7 +287,7 @@  int Grow_addbitmap(char *devname, int fd, struct context *c, struct shape *s)
 	mdu_array_info_t array;
 	struct supertype *st;
 	char *subarray = NULL;
-	int major = BITMAP_MAJOR_HI;
+	int major = c->threshold ? BITMAP_MAJOR_CHUNKFLUSH : BITMAP_MAJOR_HI;
 	unsigned long long bitmapsize, array_size;
 	struct mdinfo *mdi;
 
@@ -441,7 +441,7 @@  int Grow_addbitmap(char *devname, int fd, struct context *c, struct shape *s)
 			if (!rv) {
 				rv = st->ss->add_internal_bitmap(
 					st, &s->bitmap_chunk, c->delay,
-					s->write_behind, bitmapsize,
+					c->threshold, s->write_behind, bitmapsize,
 					offset_setable, major);
 				if (!rv) {
 					st->ss->write_bitmap(st, fd2,
@@ -512,8 +512,8 @@  int Grow_addbitmap(char *devname, int fd, struct context *c, struct shape *s)
 			return 1;
 		}
 		if (CreateBitmap(s->bitmap_file, c->force, (char*)uuid,
-				 s->bitmap_chunk, c->delay, s->write_behind,
-				 bitmapsize, major)) {
+				 s->bitmap_chunk, c->delay, c->threshold,
+				 s->write_behind, bitmapsize, major)) {
 			return 1;
 		}
 		bitmap_fd = open(s->bitmap_file, O_RDWR);
diff --git a/ReadMe.c b/ReadMe.c
index 50a5e36d..87ef4b42 100644
--- a/ReadMe.c
+++ b/ReadMe.c
@@ -81,12 +81,12 @@  char Version[] = "mdadm - v" VERSION " - " VERS_DATE EXTRAVERSION "\n";
  *     found, it is started.
  */
 
-char short_options[]="-ABCDEFGIQhVXYWZ:vqbc:i:l:p:m:n:x:u:c:d:z:U:N:sarfRSow1tye:k:";
+char short_options[]="-ABCDEFGIQhVXYWZ:vqbc:g:i:l:p:m:n:x:u:c:d:z:U:N:sarfRSow1tye:k:";
 char short_monitor_options[]="-ABCDEFGIQhVXYWZ:vqbc:i:l:p:m:r:n:x:u:c:d:z:U:N:safRSow1tye:k:";
 char short_bitmap_options[]=
-		"-ABCDEFGIQhVXYWZ:vqb:c:i:l:p:m:n:x:u:c:d:z:U:N:sarfRSow1tye:k:";
+		"-ABCDEFGIQhVXYWZ:vqb:c:g:i:l:p:m:n:x:u:c:d:z:U:N:sarfRSow1tye:k:";
 char short_bitmap_auto_options[]=
-		"-ABCDEFGIQhVXYWZ:vqb:c:i:l:p:m:n:x:u:c:d:z:U:N:sa:rfRSow1tye:k:";
+		"-ABCDEFGIQhVXYWZ:vqb:c:g:i:l:p:m:n:x:u:c:d:z:U:N:sa:rfRSow1tye:k:";
 
 struct option long_options[] = {
     {"manage",    0, 0, ManageOpt},
@@ -196,6 +196,7 @@  struct option long_options[] = {
     {"alert",     1, 0, ProgramOpt},
     {"increment", 1, 0, Increment},
     {"delay",     1, 0, 'd'},
+    {"threshold", 1, 0, 'g'},
     {"daemonise", 0, 0, Fork},
     {"daemonize", 0, 0, Fork},
     {"oneshot",   0, 0, '1'},
@@ -304,6 +305,7 @@  char OptionHelp[] =
 "  --assume-clean     : Assume the array is already in-sync. This is dangerous for RAID5.\n"
 "  --bitmap-chunk=    : chunksize of bitmap in bitmap file (Kilobytes)\n"
 "  --delay=      -d   : seconds between bitmap updates\n"
+"  --threshold=  -g   : chunks between bitmap updates\n"
 "  --write-behind=    : number of simultaneous write-behind requests to allow (requires bitmap)\n"
 "  --name=       -N   : Textual name for array - max 32 characters\n"
 "\n"
@@ -387,6 +389,7 @@  char Help_create[] =
 "  --name=            -N : Textual name for array - max 32 characters\n"
 "  --bitmap-chunk=       : bitmap chunksize in Kilobytes.\n"
 "  --delay=           -d : bitmap update delay in seconds.\n"
+"  --threshold=       -g : chunks between bitmap updates.\n"
 "  --write-journal=      : Specify journal device for RAID-4/5/6 array\n"
 "  --consistency-policy= : Specify the policy that determines how the array\n"
 "                     -k : maintains consistency in case of unexpected shutdown.\n"
@@ -412,6 +415,7 @@  char Help_build[] =
 "  --raid-devices= -n : number of active devices in array\n"
 "  --bitmap-chunk=    : bitmap chunksize in Kilobytes.\n"
 "  --delay=      -d   : bitmap update delay in seconds.\n"
+"  --threshold=  -g   : chunks between bitmap updates\n"
 ;
 
 char Help_assemble[] =
diff --git a/bitmap.c b/bitmap.c
index 9a7ffe3b..0dfdb9c7 100644
--- a/bitmap.c
+++ b/bitmap.c
@@ -33,6 +33,7 @@  static inline void sb_le_to_cpu(bitmap_super_t *sb)
 	sb->sync_size = __le64_to_cpu(sb->sync_size);
 	sb->write_behind = __le32_to_cpu(sb->write_behind);
 	sb->nodes = __le32_to_cpu(sb->nodes);
+	sb->daemon_flush_chunks = __le32_to_cpu(sb->daemon_flush_chunks);
 	sb->sectors_reserved = __le32_to_cpu(sb->sectors_reserved);
 }
 
@@ -273,7 +274,7 @@  int ExamineBitmap(char *filename, int brief, struct supertype *st)
 	}
 	printf("         Version : %d\n", sb->version);
 	if (sb->version < BITMAP_MAJOR_LO ||
-	    sb->version > BITMAP_MAJOR_CLUSTERED) {
+	    sb->version > BITMAP_MAJOR_CHUNKFLUSH) {
 		pr_err("unknown bitmap version %d, either the bitmap file\n",
 		       sb->version);
 		pr_err("is corrupted or you need to upgrade your tools\n");
@@ -311,7 +312,7 @@  int ExamineBitmap(char *filename, int brief, struct supertype *st)
 	}
 
 	printf("       Chunksize : %s\n", human_chunksize(sb->chunksize));
-	printf("          Daemon : %ds flush period\n", sb->daemon_sleep);
+	printf("          Daemon : %ds flush period, %d chunks\n", sb->daemon_sleep, sb->daemon_flush_chunks);
 	if (sb->write_behind)
 		sprintf(buf, "Allow write behind, max %d", sb->write_behind);
 	else
@@ -427,6 +428,7 @@  out:
 
 int CreateBitmap(char *filename, int force, char uuid[16],
 		 unsigned long chunksize, unsigned long daemon_sleep,
+		 unsigned int daemon_flush_chunks,
 		 unsigned long write_behind,
 		 unsigned long long array_size /* sectors */,
 		 int major)
@@ -472,6 +474,7 @@  int CreateBitmap(char *filename, int force, char uuid[16],
 		memcpy(sb.uuid, uuid, 16);
 	sb.chunksize = chunksize;
 	sb.daemon_sleep = daemon_sleep;
+	sb.daemon_flush_chunks = daemon_flush_chunks;
 	sb.write_behind = write_behind;
 	sb.sync_size = array_size;
 
diff --git a/bitmap.h b/bitmap.h
index 7b1f80f2..48ebc0b9 100644
--- a/bitmap.h
+++ b/bitmap.h
@@ -9,10 +9,12 @@ 
 #define BITMAP_MAJOR_LO 3
 /* version 4 insists the bitmap is in little-endian order
  * with version 3, it is host-endian which is non-portable
+ * Version 6 supports the flush-chunks threshold
  */
 #define BITMAP_MAJOR_HI 4
 #define	BITMAP_MAJOR_HOSTENDIAN 3
 #define	BITMAP_MAJOR_CLUSTERED 5
+#define	BITMAP_MAJOR_CHUNKFLUSH 6
 
 #define BITMAP_MINOR 39
 
@@ -159,7 +161,8 @@  typedef struct bitmap_super_s {
 				 * reserved for the bitmap. */
 	__u32 nodes;        /* 68 the maximum number of nodes in cluster. */
 	__u8 cluster_name[64]; /* 72 cluster name to which this md belongs */
-	__u8  pad[256 - 136]; /* set to zero */
+	__u32 daemon_flush_chunks; /* 136 dirty chunks between flushes */
+	__u8  pad[256 - 140]; /* set to zero */
 } bitmap_super_t;
 
 /* notes:
diff --git a/config.c b/config.c
index dc1620c1..744d5d4f 100644
--- a/config.c
+++ b/config.c
@@ -81,7 +81,7 @@  char DefaultAltConfDir[] = CONFFILE2 ".d";
 
 enum linetype { Devices, Array, Mailaddr, Mailfrom, Program, CreateDev,
 		Homehost, HomeCluster, AutoMode, Policy, PartPolicy, Sysfs,
-		MonitorDelay, LTEnd };
+		MonitorDelay, Threshold, LTEnd };
 char *keywords[] = {
 	[Devices]  = "devices",
 	[Array]    = "array",
@@ -96,6 +96,7 @@  char *keywords[] = {
 	[PartPolicy]="part-policy",
 	[Sysfs]    = "sysfs",
 	[MonitorDelay] = "monitordelay",
+	[Threshold] = "threshold",
 	[LTEnd]    = NULL
 };
 
@@ -595,6 +596,17 @@  void monitordelayline(char *line)
 	}
 }
 
+static int threshold;
+void thresholdline(char *line)
+{
+	char *w;
+
+	for (w = dl_next(line); w != line; w = dl_next(w)) {
+		if (threshold == 0)
+			threshold = strtol(w, NULL, 10);
+	}
+}
+
 char auto_yes[] = "yes";
 char auto_no[] = "no";
 char auto_homehost[] = "homehost";
@@ -779,6 +791,8 @@  void conf_file(FILE *f)
 		case MonitorDelay:
 			monitordelayline(line);
 			break;
+		case Threshold:
+			thresholdline(line);
 		default:
 			pr_err("Unknown keyword %s\n", line);
 		}
diff --git a/mdadm.c b/mdadm.c
index 972adb52..72c12406 100644
--- a/mdadm.c
+++ b/mdadm.c
@@ -912,6 +912,16 @@  int main(int argc, char *argv[])
 				exit(2);
 			}
 			continue;
+		case O(GROW, 'g'):
+		case O(BUILD,'g'): /* flush chunk threshold for bitmap updates */
+		case O(CREATE,'g'):
+			if (c.threshold)
+				pr_err("only specify threshold once. %s ignored.\n", optarg);
+			else if (parse_num(&c.threshold, optarg) != 0) {
+				pr_err("invalid threshold: %s\n", optarg);
+				exit(2);
+			}
+			continue;
 		case O(MONITOR,'f'): /* daemonise */
 		case O(MONITOR,Fork):
 			daemonise = 1;
diff --git a/mdadm.h b/mdadm.h
index 3673494e..d135a55a 100644
--- a/mdadm.h
+++ b/mdadm.h
@@ -574,6 +574,7 @@  struct context {
 	int	SparcAdjust;
 	int	autof;
 	int	delay;
+	int	threshold;
 	int	freeze_reshape;
 	char	*backup_file;
 	int	invalid_backup;
@@ -1043,7 +1044,7 @@  extern struct superswitch {
 	 * -Exxxx: On error
 	 */
 	int (*add_internal_bitmap)(struct supertype *st, int *chunkp,
-				   int delay, int write_behind,
+				   int delay, int threshold, int write_behind,
 				   unsigned long long size, int may_change, int major);
 	/* Perform additional setup required to activate a bitmap.
 	 */
@@ -1491,7 +1492,7 @@  extern int IncrementalScan(struct context *c, char *devnm);
 extern int IncrementalRemove(char *devname, char *path, int verbose);
 extern int CreateBitmap(char *filename, int force, char uuid[16],
 			unsigned long chunksize, unsigned long daemon_sleep,
-			unsigned long write_behind,
+			unsigned int daemon_flush_chunks, unsigned long write_behind,
 			unsigned long long array_size,
 			int major);
 extern int ExamineBitmap(char *filename, int brief, struct supertype *st);
diff --git a/super-intel.c b/super-intel.c
index b0565610..aadccdda 100644
--- a/super-intel.c
+++ b/super-intel.c
@@ -12645,7 +12645,7 @@  static int validate_internal_bitmap_imsm(struct supertype *st)
  *	-1 : fail
  ******************************************************************************/
 static int add_internal_bitmap_imsm(struct supertype *st, int *chunkp,
-				    int delay, int write_behind,
+				    int delay, int threshold, int write_behind,
 				    unsigned long long size, int may_change,
 				    int amajor)
 {
diff --git a/super0.c b/super0.c
index 93876e2e..369a870d 100644
--- a/super0.c
+++ b/super0.c
@@ -1123,7 +1123,7 @@  static __u64 avail_size0(struct supertype *st, __u64 devsize,
 }
 
 static int add_internal_bitmap0(struct supertype *st, int *chunkp,
-				int delay, int write_behind,
+				int delay, int threshold, int write_behind,
 				unsigned long long size, int may_change,
 				int major)
 {
@@ -1166,6 +1166,7 @@  static int add_internal_bitmap0(struct supertype *st, int *chunkp,
 	memcpy(bms->uuid, uuid, 16);
 	bms->chunksize = __cpu_to_le32(chunk);
 	bms->daemon_sleep = __cpu_to_le32(delay);
+	bms->daemon_flush_chunks = __cpu_to_le32(threshold);
 	bms->sync_size = __cpu_to_le64(size);
 	bms->write_behind = __cpu_to_le32(write_behind);
 	*chunkp = chunk;
diff --git a/super1.c b/super1.c
index 0b505a7e..67068e02 100644
--- a/super1.c
+++ b/super1.c
@@ -2466,7 +2466,8 @@  static __u64 avail_size1(struct supertype *st, __u64 devsize,
 
 static int
 add_internal_bitmap1(struct supertype *st,
-		     int *chunkp, int delay, int write_behind,
+		     int *chunkp, int delay,
+		     int threshold, int write_behind,
 		     unsigned long long size,
 		     int may_change, int major)
 {
@@ -2615,6 +2616,7 @@  add_internal_bitmap1(struct supertype *st,
 	memcpy(bms->uuid, uuid, 16);
 	bms->chunksize = __cpu_to_le32(chunk);
 	bms->daemon_sleep = __cpu_to_le32(delay);
+	bms->daemon_flush_chunks = __cpu_to_le32(threshold);
 	bms->sync_size = __cpu_to_le64(size);
 	bms->write_behind = __cpu_to_le32(write_behind);
 	bms->nodes = __cpu_to_le32(st->nodes);