*
*/
-static int geo_map(int block, unsigned long long stripe, int raid_disks,
+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 will have
*/
int pd;
+ /* layout is not relevant for raid0 and raid4 */
+ if ((level == 0) ||
+ (level == 4))
+ layout = 0;
+
switch(level*100 + layout) {
case 000:
case 400:
}
}
-static void qsyndrome(uint8_t *p, uint8_t *q, uint8_t **sources, int disks, int size)
+void qsyndrome(uint8_t *p, uint8_t *q, uint8_t **sources, int disks, int size)
{
int d, z;
uint8_t wq0, wp0, wd0, w10, w20;
uint8_t raid6_gfexp[256];
uint8_t raid6_gfinv[256];
uint8_t raid6_gfexi[256];
+uint8_t raid6_gflog[256];
+uint8_t raid6_gfilog[256];
void make_tables(void)
{
int i, j;
uint8_t v;
+ uint32_t b, log;
/* Compute multiplication table */
for (i = 0; i < 256; i++)
for (i = 0; i < 256; i ++)
raid6_gfexi[i] = raid6_gfinv[raid6_gfexp[i] ^ 1];
+ /* Compute log and inverse log */
+ /* Modified code from:
+ * http://web.eecs.utk.edu/~plank/plank/papers/CS-96-332.html
+ */
+ b = 1;
+ raid6_gflog[0] = 0;
+ raid6_gfilog[255] = 0;
+
+ for (log = 0; log < 255; log++) {
+ raid6_gflog[b] = (uint8_t) log;
+ raid6_gfilog[log] = (uint8_t) b;
+ b = b << 1;
+ if (b & 256) b = b ^ 0435;
+ }
+
tables_ready = 1;
}
uint8_t *zero;
+int zero_size;
/* Following was taken from linux/drivers/md/raid6recov.c */
/* Recover two failed data blocks. */
}
}
-/* Save data:
- * We are given:
- * A list of 'fds' of the active disks. Some may be absent.
- * 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 which must be stripe-aligned
- * 'buf' is large enough to hold one stripe, and is aligned
- */
+/* Try to find out if a specific disk has a problem */
+int raid6_check_disks(int data_disks, int start, int chunk_size,
+ int level, int layout, int diskP, int diskQ,
+ char *p, char *q, char **stripes)
+{
+ int i;
+ int data_id, diskD;
+ uint8_t Px, Qx;
+ int curr_broken_disk = -1;
+ int prev_broken_disk = -1;
+ int broken_status = 0;
+
+ for(i = 0; i < chunk_size; i++) {
+ Px = (uint8_t)stripes[diskP][i] ^ (uint8_t)p[i];
+ Qx = (uint8_t)stripes[diskQ][i] ^ (uint8_t)q[i];
+
+ if((Px != 0) && (Qx == 0))
+ curr_broken_disk = diskP;
+
+
+ if((Px == 0) && (Qx != 0))
+ curr_broken_disk = diskQ;
+
+
+ if((Px != 0) && (Qx != 0)) {
+ data_id = (raid6_gflog[Qx] - raid6_gflog[Px]);
+ if(data_id < 0) data_id += 255;
+ diskD = geo_map(data_id, start/chunk_size,
+ data_disks + 2, level, layout);
+ curr_broken_disk = diskD;
+ }
+
+ if((Px == 0) && (Qx == 0))
+ curr_broken_disk = curr_broken_disk;
+ if(curr_broken_disk >= data_disks + 2)
+ broken_status = 2;
+
+ switch(broken_status) {
+ case 0:
+ if(curr_broken_disk != -1) {
+ prev_broken_disk = curr_broken_disk;
+ broken_status = 1;
+ }
+ break;
+
+ case 1:
+ if(curr_broken_disk != prev_broken_disk)
+ broken_status = 2;
+ break;
+
+ case 2:
+ default:
+ curr_broken_disk = prev_broken_disk = -2;
+ break;
+ }
+ }
+
+ return curr_broken_disk;
+}
+
+/*******************************************************************************
+ * Function: save_stripes
+ * Description:
+ * Function reads data (only data without P and Q) from array and writes
+ * it to buf and opcjonaly to backup files
+ * Parameters:
+ * source : A list of 'fds' of the active disks.
+ * Some may be absent
+ * offsets : A list of offsets on disk belonging
+ * to the array [bytes]
+ * raid_disks : geometry: number of disks in the array
+ * chunk_size : geometry: chunk size [bytes]
+ * level : geometry: RAID level
+ * layout : geometry: layout
+ * nwrites : number of backup files
+ * dest : A list of 'fds' for mirrored targets
+ * (e.g. backup files). They are already seeked to right
+ * (write) location. If NULL, data will be wrote
+ * to the buf only
+ * start : start address of data to read (must be stripe-aligned)
+ * [bytes]
+ * length - : length of data to read (must be stripe-aligned)
+ * [bytes]
+ * buf : buffer for data. It is large enough to hold
+ * one stripe. It is stripe aligned
+ * Returns:
+ * 0 : success
+ * -1 : fail
+ ******************************************************************************/
int save_stripes(int *source, unsigned long long *offsets,
int raid_disks, int chunk_size, int level, int layout,
int nwrites, int *dest,
int data_disks = raid_disks - (level == 0 ? 0 : level <=5 ? 1 : 2);
int disk;
int i;
+ unsigned long long length_test;
if (!tables_ready)
make_tables();
- if (zero == NULL) {
+ if (zero == NULL || chunk_size > zero_size) {
+ if (zero)
+ free(zero);
zero = malloc(chunk_size);
- memset(zero, 0, chunk_size);
+ if (zero)
+ memset(zero, 0, chunk_size);
+ zero_size = chunk_size;
}
len = data_disks * chunk_size;
+ length_test = length / len;
+ length_test *= len;
+
+ if (length != length_test) {
+ dprintf("Error: save_stripes(): Data are not alligned. EXIT\n");
+ dprintf("\tArea for saving stripes (length) = %llu\n", length);
+ dprintf("\tWork step (len) = %i\n", len);
+ dprintf("\tExpected save area (length_test) = %llu\n",
+ length_test);
+ abort();
+ }
+
while (length > 0) {
int failed = 0;
int fdisk[3], fblock[3];
} else {
/* for md, q is over 'data_disks' blocks,
* starting immediately after 'q'
+ * Note that for the '_6' variety, the p block
+ * makes a hole that we need to be careful of.
*/
- for (i = 0; i < data_disks; i++) {
- int dnum = geo_map(i,
- start/chunk_size/data_disks,
- raid_disks, level, layout);
- int snum;
+ int j;
+ int snum = 0;
+ for (j = 0; j < raid_disks; j++) {
+ int dnum = (qdisk + 1 + j) % raid_disks;
+ if (dnum == disk || dnum == qdisk)
+ continue;
+ for (i = 0; i < data_disks; i++)
+ if (geo_map(i,
+ start/chunk_size/data_disks,
+ raid_disks, level, layout) == dnum)
+ break;
/* i is the logical block number, so is index to 'buf'.
* dnum is physical disk number
* snum is syndrome disk for which 0 is immediately after Q
*/
- snum = (raid_disks + dnum - qdisk - 1) % raid_disks;
bufs[snum] = (uint8_t*)buf + chunk_size * i;
+
+ if (fblock[0] == i)
+ fdisk[0] = snum;
+ if (fblock[1] == i)
+ fdisk[1] = snum;
+ snum++;
}
- fdisk[0] = (raid_disks + fdisk[0] - qdisk - 1) % raid_disks;
- fdisk[1] = (raid_disks + fdisk[1] - qdisk - 1) % raid_disks;
syndrome_disks = data_disks;
}
fdisk[0], fdisk[1], bufs);
}
}
-
- for (i=0; i<nwrites; i++)
- if (write(dest[i], buf, len) != len)
- return -1;
-
+ if (dest) {
+ for (i = 0; i < nwrites; i++)
+ if (write(dest[i], buf, len) != len)
+ return -1;
+ } else {
+ /* build next stripe in buffer */
+ buf += len;
+ }
length -= len;
start += len;
}
int restore_stripes(int *dest, unsigned long long *offsets,
int raid_disks, int chunk_size, int level, int layout,
int source, unsigned long long read_offset,
- unsigned long long start, unsigned long long length)
+ unsigned long long start, unsigned long long length,
+ char *src_buf)
{
char *stripe_buf;
char **stripes = malloc(raid_disks * sizeof(char*));
char **blocks = malloc(raid_disks * sizeof(char*));
int i;
+ int rv;
int data_disks = raid_disks - (level == 0 ? 0 : level <= 5 ? 1 : 2);
- posix_memalign((void**)&stripe_buf, 4096, raid_disks * chunk_size);
- if (zero == NULL) {
+ if (posix_memalign((void**)&stripe_buf, 4096, raid_disks * chunk_size))
+ stripe_buf = NULL;
+
+ if (zero == NULL || chunk_size > zero_size) {
+ if (zero)
+ free(zero);
zero = malloc(chunk_size);
if (zero)
memset(zero, 0, chunk_size);
+ zero_size = chunk_size;
}
+
if (stripe_buf == NULL || stripes == NULL || blocks == NULL
|| zero == NULL) {
- free(stripe_buf);
- free(stripes);
- free(blocks);
- free(zero);
- return -2;
+ rv = -2;
+ goto abort;
}
- for (i=0; i<raid_disks; i++)
+ for (i = 0; i < raid_disks; i++)
stripes[i] = stripe_buf + i * chunk_size;
while (length > 0) {
- int len = data_disks * chunk_size;
+ unsigned int len = data_disks * chunk_size;
unsigned long long offset;
int disk, qdisk;
int syndrome_disks;
- if (length < len)
- return -3;
- for (i=0; i < data_disks; i++) {
+ if (length < len) {
+ rv = -3;
+ goto abort;
+ }
+ for (i = 0; i < data_disks; i++) {
int disk = geo_map(i, start/chunk_size/data_disks,
raid_disks, level, layout);
- if (lseek64(source, read_offset, 0) != read_offset)
- return -1;
- if (read(source, stripes[disk], chunk_size) != chunk_size)
- return -1;
+ if (src_buf == NULL) {
+ /* read from file */
+ if (lseek64(source, read_offset, 0) !=
+ (off64_t)read_offset) {
+ rv = -1;
+ goto abort;
+ }
+ if (read(source,
+ stripes[disk],
+ chunk_size) != chunk_size) {
+ rv = -1;
+ goto abort;
+ }
+ } else {
+ /* read from input buffer */
+ memcpy(stripes[disk],
+ src_buf + read_offset,
+ chunk_size);
+ }
read_offset += chunk_size;
}
/* We have the data, now do the parity */
}
for (i=0; i < raid_disks ; i++)
if (dest[i] >= 0) {
- if (lseek64(dest[i], offsets[i]+offset, 0) < 0)
- return -1;
- if (write(dest[i], stripes[i], chunk_size) != chunk_size)
- return -1;
+ if (lseek64(dest[i],
+ offsets[i]+offset, 0) < 0) {
+ rv = -1;
+ goto abort;
+ }
+ if (write(dest[i], stripes[i],
+ chunk_size) != chunk_size) {
+ rv = -1;
+ goto abort;
+ }
}
length -= len;
start += len;
}
- return 0;
+ rv = 0;
+
+abort:
+ free(stripe_buf);
+ free(stripes);
+ free(blocks);
+ return rv;
}
#ifdef MAIN
char *q = malloc(chunk_size);
int i;
+ int diskP, diskQ;
int data_disks = raid_disks - (level == 5 ? 1: 2);
+
+ if (!tables_ready)
+ make_tables();
+
for ( i = 0 ; i < raid_disks ; i++)
stripes[i] = stripe_buf + i * chunk_size;
}
switch(level) {
case 6:
- qsyndrome(p, q, blocks, data_disks, chunk_size);
- disk = geo_map(-1, start/chunk_size, raid_disks,
+ qsyndrome(p, q, (uint8_t**)blocks, data_disks, chunk_size);
+ diskP = 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,
+ if (memcmp(p, stripes[diskP], chunk_size) != 0) {
+ printf("P(%d) wrong at %llu\n", diskP,
start / chunk_size);
}
- disk = geo_map(-2, start/chunk_size, raid_disks,
+ diskQ = 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,
+ if (memcmp(q, stripes[diskQ], chunk_size) != 0) {
+ printf("Q(%d) wrong at %llu\n", diskQ,
start / chunk_size);
}
+ disk = raid6_check_disks(data_disks, start, chunk_size,
+ level, layout, diskP, diskQ,
+ p, q, stripes);
+ if(disk >= 0) {
+ printf("Possible failed disk: %d\n", disk);
+ }
+ if(disk == -2) {
+ printf("Failure detected, but disk unknown\n");
+ }
break;
}
length -= chunk_size;
exit(3);
}
for (i=0; i<raid_disks; i++) {
+ char *p;
+ p = strchr(argv[9+i], ':');
+
+ if(p != NULL) {
+ *p++ = '\0';
+ offsets[i] = atoll(p) * 512;
+ }
+
fds[i] = open(argv[9+i], O_RDWR);
if (fds[i] < 0) {
perror(argv[9+i]);
int rv = restore_stripes(fds, offsets,
raid_disks, chunk_size, level, layout,
storefd, 0ULL,
- start, length);
+ start, length, NULL);
if (rv != 0) {
fprintf(stderr,
"test_stripe: restore_stripes returned %d\n",
projects / thirdparty / mdadm.git / blobdiff