[RFC PATCH] mdadm: Add parameter for bitmap chunk threshold
From: Jonathan Derrick
Date: Thu Oct 06 2022 - 18:09:28 EST
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@xxxxxxxxx>
---
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(-)
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);
--
2.31.1