static int geo_map(int block, unsigned long long stripe, int raid_disks, int level, int layout)
{
- /* On the given stripe, find which disk in the array with have
+ /* On the given stripe, find which disk in the array will have
* block numbered 'block'.
+ * '-1' means the parity block.
+ * '-2' means the Q syndrome.
*/
int pd;
case 600 + ALGORITHM_LEFT_ASYMMETRIC:
pd = raid_disks - 1 - (stripe % raid_disks);
if (block == -1) return pd;
+ if (block == -2) return (pd+1) % raid_disks;
if (pd == raid_disks - 1)
return block+1;
if (block >= pd)
case 600 + ALGORITHM_RIGHT_ASYMMETRIC:
pd = stripe % raid_disks;
if (block == -1) return pd;
+ if (block == -2) return (pd+1) % raid_disks;
if (pd == raid_disks - 1)
return block+1;
if (block >= pd)
case 600 + ALGORITHM_LEFT_SYMMETRIC:
pd = raid_disks - 1 - (stripe % raid_disks);
if (block == -1) return pd;
+ if (block == -2) return (pd+1) % raid_disks;
return (pd + 2 + block) % raid_disks;
case 600 + ALGORITHM_RIGHT_SYMMETRIC:
pd = stripe % raid_disks;
if (block == -1) return pd;
+ if (block == -2) return (pd+1) % raid_disks;
return (pd + 2 + block) % raid_disks;
}
return -1;
}
}
+static void qsyndrome(char *p, char *q, char **sources, int disks, int size)
+{
+ int d, z;
+ char wq0, wp0, wd0, w10, w20;
+ for ( d = 0; d < size; d++) {
+ wq0 = wp0 = sources[disks-1][d];
+ for ( z = disks-2 ; z >= 0 ; z-- ) {
+ wd0 = sources[z][d];
+ wp0 ^= wd0;
+ w20 = (wq0&0x80) ? 0xff : 0x00;
+ w10 = (wq0 << 1) & 0xff;
+ w20 &= 0x1d;
+ w10 ^= w20;
+ wq0 = w10 ^ wd0;
+ }
+ p[d] = wp0;
+ q[d] = wq0;
+ }
+}
+
/* Save data:
* We are given:
* A list of 'fds' of the active disks. For now we require all to be present.
- * A geomtry: raid_disks, chunk_size, level, layout
+ * A geometry: raid_disks, chunk_size, level, layout
* A list of 'fds' for mirrored targets. They are already seeked to
* right (Write) location
* A start and length
int nwrites, int *dest,
unsigned long long start, unsigned long long length)
{
- char buf[8192];
+ char abuf[8192+512];
+ char *buf = (char*)(((unsigned long)abuf+511)&~511UL);
int cpos = start % chunk_size; /* where in chunk we are up to */
int len;
int data_disks = raid_disks - (level == 0 ? 0 : level <=5 ? 1 : 2);
unsigned long long offset;
int i;
len = chunk_size - cpos;
- if (len > sizeof(buf)) len = sizeof(buf);
+ if (len > 8192) len = 8192;
if (len > length) len = length;
/* len bytes to be moved from one device */
while (length > 0) {
int len = data_disks * chunk_size;
unsigned long long offset;
+ int disk, qdisk;
if (length < len)
return -3;
for (i=0; i < data_disks; i++) {
}
/* We have the data, now do the parity */
offset = (start/chunk_size/data_disks) * chunk_size;
- if (level >= 4) {
- int disk = geo_map(-1, start/chunk_size/data_disks,
+ switch (level) {
+ case 4:
+ case 5:
+ disk = geo_map(-1, start/chunk_size/data_disks,
raid_disks, level, layout);
xor_blocks(stripes[disk], blocks, data_disks, chunk_size);
- /* FIXME need to do raid6 Q as well */
+ break;
+ case 6:
+ disk = geo_map(-1, start/chunk_size/data_disks,
+ raid_disks, level, layout);
+ qdisk = geo_map(-2, start/chunk_size/data_disks,
+ raid_disks, level, layout);
+
+ qsyndrome(stripes[disk], stripes[qdisk], blocks,
+ data_disks, chunk_size);
+ break;
}
for (i=0; i < raid_disks ; i++)
if (dest[i] >= 0) {
#ifdef MAIN
+int test_stripes(int *source, unsigned long long *offsets,
+ int raid_disks, int chunk_size, int level, int layout,
+ unsigned long long start, unsigned long long length)
+{
+ /* ready the data and p (and q) blocks, and check we got them right */
+ char *stripe_buf = malloc(raid_disks * chunk_size);
+ char **stripes = malloc(raid_disks * sizeof(char*));
+ char **blocks = malloc(raid_disks * sizeof(char*));
+ char *p = malloc(chunk_size);
+ char *q = malloc(chunk_size);
+
+ int i;
+ int data_disks = raid_disks - (level == 5 ? 1: 2);
+ for ( i = 0 ; i < raid_disks ; i++)
+ stripes[i] = stripe_buf + i * chunk_size;
+
+ while (length > 0) {
+ int disk;
+
+ for (i = 0 ; i < raid_disks ; i++) {
+ lseek64(source[i], offsets[i]+start, 0);
+ read(source[i], stripes[i], chunk_size);
+ }
+ for (i = 0 ; i < data_disks ; i++) {
+ int disk = geo_map(i, start/chunk_size, raid_disks,
+ level, layout);
+ blocks[i] = stripes[disk];
+ printf("%d->%d\n", i, disk);
+ }
+ switch(level) {
+ case 6:
+ qsyndrome(p, q, blocks, data_disks, chunk_size);
+ disk = geo_map(-1, start/chunk_size, raid_disks,
+ level, layout);
+ if (memcmp(p, stripes[disk], chunk_size) != 0) {
+ printf("P(%d) wrong at %llu\n", disk,
+ start / chunk_size);
+ }
+ disk = geo_map(-2, start/chunk_size, raid_disks,
+ level, layout);
+ if (memcmp(q, stripes[disk], chunk_size) != 0) {
+ printf("Q(%d) wrong at %llu\n", disk,
+ start / chunk_size);
+ }
+ break;
+ }
+ length -= chunk_size;
+ start += chunk_size;
+ }
+ return 0;
+}
+
unsigned long long getnum(char *str, char **err)
{
char *e;
save = 1;
else if (strcmp(argv[1], "restore") == 0)
save = 0;
+ else if (strcmp(argv[1], "test") == 0)
+ save = 2;
else {
fprintf(stderr, "test_stripe: must give 'save' or 'restore'.\n");
exit(2);
}
}
- if (save) {
+ if (save == 1) {
int rv = save_stripes(fds, offsets,
raid_disks, chunk_size, level, layout,
1, &storefd,
start, length);
if (rv != 0) {
- fprintf(stderr, "test_stripe: save_stripes returned %d\n", rv);
+ fprintf(stderr,
+ "test_stripe: save_stripes returned %d\n", rv);
+ exit(1);
+ }
+ } else if (save == 2) {
+ int rv = test_stripes(fds, offsets,
+ raid_disks, chunk_size, level, layout,
+ start, length);
+ if (rv != 0) {
+ fprintf(stderr,
+ "test_stripe: test_stripes returned %d\n", rv);
exit(1);
}
} else {
storefd, 0ULL,
start, length);
if (rv != 0) {
- fprintf(stderr, "test_stripe: restore_stripes returned %d\n", rv);
+ fprintf(stderr,
+ "test_stripe: restore_stripes returned %d\n",
+ rv);
exit(1);
}
}
projects / thirdparty / mdadm.git / blobdiff