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Differential D18299 Diff 51026 head/stand/common/bcache.c

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head/stand/common/bcache.c

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static u_int bcache_bcount; static u_int bcache_bcount;
static u_int bcache_rablks; static u_int bcache_rablks;
#define BHASH(bc, blkno) ((blkno) & ((bc)->bcache_nblks - 1)) #define BHASH(bc, blkno) ((blkno) & ((bc)->bcache_nblks - 1))
#define BCACHE_LOOKUP(bc, blkno) \ #define BCACHE_LOOKUP(bc, blkno) \
((bc)->bcache_ctl[BHASH((bc), (blkno))].bc_blkno != (blkno)) ((bc)->bcache_ctl[BHASH((bc), (blkno))].bc_blkno != (blkno))
#define BCACHE_READAHEAD 256 #define BCACHE_READAHEAD 256
#define BCACHE_MINREADAHEAD 32 #define BCACHE_MINREADAHEAD 32
#define BCACHE_MARKER 0xdeadbeef
static void bcache_invalidate(struct bcache *bc, daddr_t blkno); static void bcache_invalidate(struct bcache *bc, daddr_t blkno);
static void bcache_insert(struct bcache *bc, daddr_t blkno); static void bcache_insert(struct bcache *bc, daddr_t blkno);
static void bcache_free_instance(struct bcache *bc); static void bcache_free_instance(struct bcache *bc);
/* /*
* Initialise the cache for (nblks) of (bsize). * Initialise the cache for (nblks) of (bsize).
*/ */
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} }
void * void *
bcache_allocate(void) bcache_allocate(void)
{ {
u_int i; u_int i;
struct bcache *bc = malloc(sizeof (struct bcache)); struct bcache *bc = malloc(sizeof (struct bcache));
int disks = bcache_numdev; int disks = bcache_numdev;
uint32_t *marker;
if (disks == 0) if (disks == 0)
disks = 1; /* safe guard */ disks = 1; /* safe guard */
if (bc == NULL) { if (bc == NULL) {
errno = ENOMEM; errno = ENOMEM;
return (bc); return (bc);
} }
/* /*
* the bcache block count must be power of 2 for hash function * the bcache block count must be power of 2 for hash function
*/ */
i = fls(disks) - 1; /* highbit - 1 */ i = fls(disks) - 1; /* highbit - 1 */
if (disks > (1 << i)) /* next power of 2 */ if (disks > (1 << i)) /* next power of 2 */
i++; i++;
bc->bcache_nblks = bcache_total_nblks >> i; bc->bcache_nblks = bcache_total_nblks >> i;
bcache_unit_nblks = bc->bcache_nblks; bcache_unit_nblks = bc->bcache_nblks;
bc->bcache_data = malloc(bc->bcache_nblks * bcache_blksize + bc->bcache_data = malloc(bc->bcache_nblks * bcache_blksize);
sizeof(uint32_t));
if (bc->bcache_data == NULL) { if (bc->bcache_data == NULL) {
/* dont error out yet. fall back to 32 blocks and try again */ /* dont error out yet. fall back to 32 blocks and try again */
bc->bcache_nblks = 32; bc->bcache_nblks = 32;
bc->bcache_data = malloc(bc->bcache_nblks * bcache_blksize + bc->bcache_data = malloc(bc->bcache_nblks * bcache_blksize +
sizeof(uint32_t)); sizeof(uint32_t));
} }
bc->bcache_ctl = malloc(bc->bcache_nblks * sizeof(struct bcachectl)); bc->bcache_ctl = malloc(bc->bcache_nblks * sizeof(struct bcachectl));
if ((bc->bcache_data == NULL) || (bc->bcache_ctl == NULL)) { if ((bc->bcache_data == NULL) || (bc->bcache_ctl == NULL)) {
bcache_free_instance(bc); bcache_free_instance(bc);
errno = ENOMEM; errno = ENOMEM;
return (NULL); return (NULL);
} }
/* Insert cache end marker. */
marker = (uint32_t *)(bc->bcache_data + bc->bcache_nblks * bcache_blksize);
*marker = BCACHE_MARKER;
/* Flush the cache */ /* Flush the cache */
for (i = 0; i < bc->bcache_nblks; i++) { for (i = 0; i < bc->bcache_nblks; i++) {
bc->bcache_ctl[i].bc_count = -1; bc->bcache_ctl[i].bc_count = -1;
bc->bcache_ctl[i].bc_blkno = -1; bc->bcache_ctl[i].bc_blkno = -1;
} }
bcache_units++; bcache_units++;
bc->ra = BCACHE_READAHEAD; /* optimistic read ahead */ bc->ra = BCACHE_READAHEAD; /* optimistic read ahead */
▲ Show 20 Lines • Show All 45 Lines • ▼ Show 20 Linesread_strategy(void *devdata, int rw, daddr_t blk, size_t size,
char *buf, size_t *rsize) char *buf, size_t *rsize)
{ {
struct bcache_devdata *dd = (struct bcache_devdata *)devdata; struct bcache_devdata *dd = (struct bcache_devdata *)devdata;
struct bcache *bc = dd->dv_cache; struct bcache *bc = dd->dv_cache;
size_t i, nblk, p_size, r_size, complete, ra; size_t i, nblk, p_size, r_size, complete, ra;
int result; int result;
daddr_t p_blk; daddr_t p_blk;
caddr_t p_buf; caddr_t p_buf;
uint32_t *marker;
if (bc == NULL) { if (bc == NULL) {
errno = ENODEV; errno = ENODEV;
return (-1); return (-1);
} }
marker = (uint32_t *)(bc->bcache_data + bc->bcache_nblks * bcache_blksize);
if (rsize != NULL) if (rsize != NULL)
*rsize = 0; *rsize = 0;
nblk = size / bcache_blksize; nblk = size / bcache_blksize;
if (nblk == 0 && size != 0) if (nblk == 0 && size != 0)
nblk++; nblk++;
result = 0; result = 0;
complete = 1; complete = 1;
▲ Show 20 Lines • Show All 101 Lines • ▼ Show 20 Lines if (BCACHE_LOOKUP(bc, (daddr_t)(blk + i)))
} }
if (size > i * bcache_blksize) if (size > i * bcache_blksize)
size = i * bcache_blksize; size = i * bcache_blksize;
if (size != 0) { if (size != 0) {
bcopy(bc->bcache_data + (bcache_blksize * BHASH(bc, blk)), buf, size); bcopy(bc->bcache_data + (bcache_blksize * BHASH(bc, blk)), buf, size);
result = 0; result = 0;
}
if (*marker != BCACHE_MARKER) {
printf("BUG: bcache corruption detected: nblks: %zu p_blk: %lu, "
"p_size: %zu, ra: %zu\n", bc->bcache_nblks,
(long unsigned)BHASH(bc, p_blk), p_size, ra);
} }
done: done:
if ((result == 0) && (rsize != NULL)) if ((result == 0) && (rsize != NULL))
*rsize = size; *rsize = size;
return(result); return(result);
} }
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