* Copyright (c) 2001-2006 Apple Computer, Inc. All rights reserved.
*
* @APPLE_OSREFERENCE_LICENSE_HEADER_START@
- *
+ *
* This file contains Original Code and/or Modifications of Original Code
* as defined in and that are subject to the Apple Public Source License
* Version 2.0 (the 'License'). You may not use this file except in
* unlawful or unlicensed copies of an Apple operating system, or to
* circumvent, violate, or enable the circumvention or violation of, any
* terms of an Apple operating system software license agreement.
- *
+ *
* Please obtain a copy of the License at
* http://www.opensource.apple.com/apsl/ and read it before using this file.
- *
+ *
* The Original Code and all software distributed under the License are
* distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
* EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
* FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
* Please see the License for the specific language governing rights and
* limitations under the License.
- *
+ *
* @APPLE_OSREFERENCE_LICENSE_HEADER_END@
*/
* 2) a band map to map a "band" within the original file to a corresponding
* "band" in the shadow file. Each band has the same size.
*
- * The band map is used to ensure that blocks that are contiguous in the
+ * The band map is used to ensure that blocks that are contiguous in the
* original file will remain contiguous in the shadow file.
*
* For debugging purposes, this file can be compiled standalone using:
/*
* Modification History
*
- * December 21, 2001 Dieter Siegmund (dieter@apple.com)
+ * December 21, 2001 Dieter Siegmund (dieter@apple.com)
* - initial revision
*/
#include <sys/param.h>
#ifdef TEST_SHADOW
#include <unistd.h>
#include <stdlib.h>
-#define my_malloc(a) malloc(a)
-#define my_free(a) free(a)
+#define my_malloc(a) malloc(a)
+#define my_free(a) free(a)
#else /* !TEST_SHADOW */
#include <sys/malloc.h>
-#define my_malloc(a) _MALLOC(a, M_TEMP, M_WAITOK)
-#define my_free(a) FREE(a, M_TEMP)
+#define my_malloc(a) _MALLOC(a, M_TEMP, M_WAITOK)
+#define my_free(a) FREE(a, M_TEMP)
#include <libkern/libkern.h>
#endif /* TEST_SHADOW */
#include "shadow.h"
-#define ULONG_ALL_ONES ((u_long)(-1))
-#define USHORT_ALL_ONES ((u_short)(-1))
-#define UCHAR_ALL_ONES ((u_char)(-1))
+#define UINT32_ALL_ONES ((uint32_t)(-1))
+#define USHORT_ALL_ONES ((u_short)(-1))
+#define UCHAR_ALL_ONES ((u_char)(-1))
-#define my_trunc(value, divisor) ((value) / (divisor) * (divisor))
+#define my_trunc(value, divisor) ((value) / (divisor) * (divisor))
/* a band size of 128K can represent a file up to 8GB */
-#define BAND_SIZE_DEFAULT_POWER_2 17
-#define BAND_SIZE_DEFAULT (1 << BAND_SIZE_DEFAULT_POWER_2)
+#define BAND_SIZE_DEFAULT_POWER_2 17
+#define BAND_SIZE_DEFAULT (1 << BAND_SIZE_DEFAULT_POWER_2)
-typedef u_short band_number_t;
-#define BAND_ZERO ((band_number_t)0)
-#define BAND_MAX ((band_number_t)65535)
+typedef u_short band_number_t;
+#define BAND_ZERO ((band_number_t)0)
+#define BAND_MAX ((band_number_t)65535)
struct shadow_map {
- u_long blocks_per_band;/* size in blocks */
- u_long block_size;
- u_char * block_bitmap; /* 1 bit per block; 1=written */
- band_number_t * bands; /* band map array */
- u_long file_size_blocks; /* size of file in bands */
- u_long shadow_size_bands; /* size of shadow in bands */
- u_long next_band; /* next free band */
- u_long zeroth_band; /* special-case 0th band */
+ uint32_t blocks_per_band;/* size in blocks */
+ uint32_t block_size;
+ u_char * block_bitmap; /* 1 bit per block; 1=written */
+ band_number_t * bands; /* band map array */
+ uint32_t file_size_blocks; /* size of file in bands */
+ uint32_t shadow_size_bands; /* size of shadow in bands */
+ uint32_t next_band; /* next free band */
+ uint32_t zeroth_band; /* special-case 0th band */
};
typedef struct {
- u_long byte;
- u_long bit;
+ uint64_t byte;
+ uint32_t bit;
} bitmap_offset_t;
static __inline__ u_char
bit(int b)
{
- return ((u_char)(1 << b));
+ return (u_char)(1 << b);
}
-/*
+/*
* Function: bits_lower
* Purpose:
* Return a byte value in which bits numbered lower than 'b' are set.
static __inline__ u_char
bits_lower(int b)
{
- return ((u_char)(bit(b) - 1));
+ return (u_char)(bit(b) - 1);
}
/*
static __inline__ u_char
byte_set_bits(int start, int end)
{
- return ((u_char)((~bits_lower(start)) & (bits_lower(end) | bit(end))));
+ return (u_char)((~bits_lower(start)) & (bits_lower(end) | bit(end)));
}
static __inline__ bitmap_offset_t
bitmap_offset(off_t where)
{
- bitmap_offset_t b;
+ bitmap_offset_t b;
- b.byte = where / NBBY;
- b.bit = where % NBBY;
- return (b);
+ b.byte = where / NBBY;
+ b.bit = where % NBBY;
+ return b;
}
-/*
+/*
* Function: bitmap_set
*
* Purpose:
* units, using longs, then a short, then a byte, then bits.
*/
static void
-bitmap_set(u_char * map, u_long start_bit, u_long bit_count)
+bitmap_set(u_char * map, off_t start_bit, size_t bit_count)
{
- bitmap_offset_t start;
- bitmap_offset_t end;
-
- start = bitmap_offset(start_bit);
- end = bitmap_offset(start_bit + bit_count);
- if (start.byte < end.byte) {
- u_long n_bytes;
-
- if (start.bit) {
- map[start.byte] |= byte_set_bits(start.bit, NBBY - 1);
- start.bit = 0;
- start.byte++;
- if (start.byte == end.byte)
- goto end;
- }
-
- n_bytes = end.byte - start.byte;
-
- while (n_bytes >= (sizeof(u_long))) {
- *((u_long *)(map + start.byte)) = ULONG_ALL_ONES;
- start.byte += sizeof(u_long);
- n_bytes -= sizeof(u_long);
- }
- if (n_bytes >= sizeof(u_short)) {
- *((u_short *)(map + start.byte)) = USHORT_ALL_ONES;
- start.byte += sizeof(u_short);
- n_bytes -= sizeof(u_short);
- }
- if (n_bytes == 1) {
- map[start.byte] = UCHAR_ALL_ONES;
- start.byte++;
- n_bytes = 0;
+ bitmap_offset_t start;
+ bitmap_offset_t end;
+
+ start = bitmap_offset(start_bit);
+ end = bitmap_offset(start_bit + bit_count);
+ if (start.byte < end.byte) {
+ uint64_t n_bytes;
+
+ if (start.bit) {
+ map[start.byte] |= byte_set_bits(start.bit, NBBY - 1);
+ start.bit = 0;
+ start.byte++;
+ if (start.byte == end.byte) {
+ goto end;
+ }
+ }
+
+ n_bytes = end.byte - start.byte;
+
+ while (n_bytes >= (sizeof(uint32_t))) {
+ *((uint32_t *)(map + start.byte)) = UINT32_ALL_ONES;
+ start.byte += sizeof(uint32_t);
+ n_bytes -= sizeof(uint32_t);
+ }
+ if (n_bytes >= sizeof(u_short)) {
+ *((u_short *)(map + start.byte)) = USHORT_ALL_ONES;
+ start.byte += sizeof(u_short);
+ n_bytes -= sizeof(u_short);
+ }
+ if (n_bytes == 1) {
+ map[start.byte] = UCHAR_ALL_ONES;
+ start.byte++;
+ n_bytes = 0;
+ }
}
- }
- end:
- if (end.bit > start.bit) {
- map[start.byte] |= byte_set_bits(start.bit, end.bit - 1);
- }
+end:
+ if (end.bit > start.bit) {
+ map[start.byte] |= byte_set_bits(start.bit, end.bit - 1);
+ }
- return;
+ return;
}
/*
* a byte, then any remaining bits to find the bit that is different.
*/
-static u_long
-bitmap_get(u_char * map, u_long start_bit, u_long bit_count,
- boolean_t * ret_is_set)
+static uint32_t
+bitmap_get(u_char * map, off_t start_bit, size_t bit_count,
+ boolean_t * ret_is_set)
{
- u_long count;
- int i;
- boolean_t is_set;
- bitmap_offset_t start;
- bitmap_offset_t end;
-
- start = bitmap_offset(start_bit);
- end = bitmap_offset(start_bit + bit_count);
-
- is_set = (map[start.byte] & bit(start.bit)) ? TRUE : FALSE;
- count = 0;
-
- if (start.byte < end.byte) {
- u_long n_bytes;
-
- if (start.bit) { /* try to align to a byte */
- for (i = start.bit; i < NBBY; i++) {
- boolean_t this_is_set;
+ uint32_t count;
+ int i;
+ boolean_t is_set;
+ bitmap_offset_t start;
+ bitmap_offset_t end;
+
+ start = bitmap_offset(start_bit);
+ end = bitmap_offset(start_bit + bit_count);
+
+ is_set = (map[start.byte] & bit(start.bit)) ? TRUE : FALSE;
+ count = 0;
+
+ if (start.byte < end.byte) {
+ uint64_t n_bytes;
+
+ if (start.bit) { /* try to align to a byte */
+ for (i = start.bit; i < NBBY; i++) {
+ boolean_t this_is_set;
+
+ this_is_set = (map[start.byte] & bit(i)) ? TRUE : FALSE;
+ if (this_is_set != is_set) {
+ goto done; /* found bit that was different, we're done */
+ }
+ count++;
+ }
+ start.bit = 0; /* made it to the next byte */
+ start.byte++;
+ if (start.byte == end.byte) {
+ goto end; /* no more bytes, check for any leftover bits */
+ }
+ }
+ /* calculate how many bytes are left in the range */
+ n_bytes = end.byte - start.byte;
+
+ /* check for 4 bytes of the same bits */
+ while (n_bytes >= sizeof(uint32_t)) {
+ uint32_t * valPtr = (uint32_t *)(map + start.byte);
+ if ((is_set && *valPtr == UINT32_ALL_ONES)
+ || (!is_set && *valPtr == 0)) {
+ count += sizeof(*valPtr) * NBBY;
+ start.byte += sizeof(*valPtr);
+ n_bytes -= sizeof(*valPtr);
+ } else {
+ break; /* bits differ */
+ }
+ }
+ /* check for 2 bytes of the same bits */
+ if (n_bytes >= sizeof(u_short)) {
+ u_short * valPtr = (u_short *)(map + start.byte);
+
+ if ((is_set && *valPtr == USHORT_ALL_ONES)
+ || (!is_set && (*valPtr == 0))) {
+ count += sizeof(*valPtr) * NBBY;
+ start.byte += sizeof(*valPtr);
+ n_bytes -= sizeof(*valPtr);
+ }
+ }
- this_is_set = (map[start.byte] & bit(i)) ? TRUE : FALSE;
- if (this_is_set != is_set) {
- goto done; /* found bit that was different, we're done */
+ /* check for 1 byte of the same bits */
+ if (n_bytes) {
+ if ((is_set && map[start.byte] == UCHAR_ALL_ONES)
+ || (!is_set && map[start.byte] == 0)) {
+ count += NBBY;
+ start.byte++;
+ n_bytes--;
+ }
+ /* we found bits that were different, find the first one */
+ if (n_bytes) {
+ for (i = 0; i < NBBY; i++) {
+ boolean_t this_is_set;
+
+ this_is_set = (map[start.byte] & bit(i)) ? TRUE : FALSE;
+ if (this_is_set != is_set) {
+ break;
+ }
+ count++;
+ }
+ goto done;
+ }
}
- count++;
- }
- start.bit = 0; /* made it to the next byte */
- start.byte++;
- if (start.byte == end.byte)
- goto end; /* no more bytes, check for any leftover bits */
}
- /* calculate how many bytes are left in the range */
- n_bytes = end.byte - start.byte;
-
- /* check for 4 bytes of the same bits */
- while (n_bytes >= sizeof(u_long)) {
- u_long * valPtr = (u_long *)(map + start.byte);
- if ((is_set && *valPtr == ULONG_ALL_ONES)
- || (!is_set && *valPtr == 0)) {
- count += sizeof(*valPtr) * NBBY;
- start.byte += sizeof(*valPtr);
- n_bytes -= sizeof(*valPtr);
- }
- else
- break; /* bits differ */
- }
- /* check for 2 bytes of the same bits */
- if (n_bytes >= sizeof(u_short)) {
- u_short * valPtr = (u_short *)(map + start.byte);
-
- if ((is_set && *valPtr == USHORT_ALL_ONES)
- || (!is_set && (*valPtr == 0))) {
- count += sizeof(*valPtr) * NBBY;
- start.byte += sizeof(*valPtr);
- n_bytes -= sizeof(*valPtr);
- }
- }
+end:
+ for (i = start.bit; i < (int)end.bit; i++) {
+ boolean_t this_is_set = (map[start.byte] & bit(i)) ? TRUE : FALSE;
- /* check for 1 byte of the same bits */
- if (n_bytes) {
- if ((is_set && map[start.byte] == UCHAR_ALL_ONES)
- || (!is_set && map[start.byte] == 0)) {
- count += NBBY;
- start.byte++;
- n_bytes--;
- }
- /* we found bits that were different, find the first one */
- if (n_bytes) {
- for (i = 0; i < NBBY; i++) {
- boolean_t this_is_set;
-
- this_is_set = (map[start.byte] & bit(i)) ? TRUE : FALSE;
- if (this_is_set != is_set) {
+ if (this_is_set != is_set) {
break;
- }
- count++;
}
- goto done;
- }
- }
- }
-
- end:
- for (i = start.bit; i < (int)end.bit; i++) {
- boolean_t this_is_set = (map[start.byte] & bit(i)) ? TRUE : FALSE;
-
- if (this_is_set != is_set) {
- break;
+ count++;
}
- count++;
- }
- done:
- *ret_is_set = is_set;
- return (count);
+done:
+ *ret_is_set = is_set;
+ return count;
}
static __inline__ band_number_t
-shadow_map_block_to_band(shadow_map_t * map, unsigned long block)
+shadow_map_block_to_band(shadow_map_t * map, off_t block)
{
- return (block / map->blocks_per_band);
+ return (band_number_t)(block / map->blocks_per_band);
}
/*
*/
static boolean_t
shadow_map_mapped_band(shadow_map_t * map, band_number_t band,
- boolean_t map_it, band_number_t * mapped_band)
+ boolean_t map_it, band_number_t * mapped_band)
{
- boolean_t is_mapped = FALSE;
-
- if (band == map->zeroth_band) {
- *mapped_band = BAND_ZERO;
- is_mapped = TRUE;
- }
- else {
- *mapped_band = map->bands[band];
- if (*mapped_band == BAND_ZERO) {
- if (map_it) {
- /* grow the file */
- if (map->next_band == 0) {
- /* remember the zero'th band */
- map->zeroth_band = band;
- }
- *mapped_band = map->bands[band] = map->next_band++;
+ boolean_t is_mapped = FALSE;
+
+ if (band == map->zeroth_band) {
+ *mapped_band = BAND_ZERO;
is_mapped = TRUE;
- }
- }
- else {
- is_mapped = TRUE;
+ } else {
+ *mapped_band = map->bands[band];
+ if (*mapped_band == BAND_ZERO) {
+ if (map_it) {
+ /* grow the file */
+ if (map->next_band == 0) {
+ /* remember the zero'th band */
+ map->zeroth_band = band;
+ }
+ *mapped_band = map->bands[band] = (band_number_t)map->next_band++;
+ is_mapped = TRUE;
+ }
+ } else {
+ is_mapped = TRUE;
+ }
}
- }
- return (is_mapped);
+ return is_mapped;
}
-/*
+/*
* Function: shadow_map_contiguous
*
* Purpose:
- * Return the first offset within the range position..(position + count)
+ * Return the first offset within the range position..(position + count)
* that is not a contiguous mapped band.
*
* If called with is_write = TRUE, this function will map bands as it goes.
*/
-static u_long
-shadow_map_contiguous(shadow_map_t * map, u_long start_block,
- u_long num_blocks, boolean_t is_write)
+static off_t
+shadow_map_contiguous(shadow_map_t * map, off_t start_block,
+ size_t num_blocks, boolean_t is_write)
{
- band_number_t band = shadow_map_block_to_band(map, start_block);
- u_long end_block = start_block + num_blocks;
- boolean_t is_mapped;
- band_number_t mapped_band;
- u_long ret_end_block = end_block;
- u_long p;
-
- is_mapped = shadow_map_mapped_band(map, band, is_write, &mapped_band);
- if (is_write == FALSE && is_mapped == FALSE) {
- static int happened = 0;
- /* this can't happen */
- if (happened == 0) {
- printf("shadow_map_contiguous: this can't happen!\n");
- happened = 1;
- }
- return (start_block);
- }
- for (p = my_trunc(start_block + map->blocks_per_band,
- map->blocks_per_band);
- p < end_block; p += map->blocks_per_band) {
- band_number_t next_mapped_band;
-
- band++;
- is_mapped = shadow_map_mapped_band(map, band, is_write,
- &next_mapped_band);
+ band_number_t band = shadow_map_block_to_band(map, start_block);
+ off_t end_block = start_block + num_blocks;
+ boolean_t is_mapped;
+ band_number_t mapped_band;
+ off_t ret_end_block = end_block;
+ off_t p;
+
+ is_mapped = shadow_map_mapped_band(map, band, is_write, &mapped_band);
if (is_write == FALSE && is_mapped == FALSE) {
- return (p);
+ static int happened = 0;
+ /* this can't happen */
+ if (happened == 0) {
+ printf("shadow_map_contiguous: this can't happen!\n");
+ happened = 1;
+ }
+ return start_block;
}
- if ((mapped_band + 1) != next_mapped_band) {
- /* not contiguous */
- ret_end_block = p;
- break;
+ for (p = my_trunc(start_block + map->blocks_per_band,
+ map->blocks_per_band);
+ p < end_block; p += map->blocks_per_band) {
+ band_number_t next_mapped_band;
+
+ band++;
+ is_mapped = shadow_map_mapped_band(map, band, is_write,
+ &next_mapped_band);
+ if (is_write == FALSE && is_mapped == FALSE) {
+ return p;
+ }
+ if ((mapped_band + 1) != next_mapped_band) {
+ /* not contiguous */
+ ret_end_block = p;
+ break;
+ }
+ mapped_band = next_mapped_band;
}
- mapped_band = next_mapped_band;
- }
- return (ret_end_block);
+ return ret_end_block;
}
-/*
+/*
* Function: block_bitmap_size
* Purpose:
- * The number of bytes required in a block bitmap to represent a file of size
+ * The number of bytes required in a block bitmap to represent a file of size
* file_size.
*
* The bytes required is the number of blocks in the file,
* particularly since most of the bits will be zero.
* A sparse bitmap would really help in this case.
*/
-static __inline__ u_long
-block_bitmap_size(off_t file_size, u_long block_size)
+static __inline__ size_t
+block_bitmap_size(off_t file_size, uint32_t block_size)
{
- off_t blocks = howmany(file_size, block_size);
- return (howmany(blocks, NBBY));
+ off_t blocks = howmany(file_size, block_size);
+ return howmany(blocks, NBBY);
}
/*
* The output values (*incr_block_offset, *incr_block_count) refer to the
* shadow file if the return value is TRUE. They refer to the original
* file if the return value is FALSE.
-
+ *
* Blocks within a band may or may not have been written, in addition,
* Bands are not necessarily contiguous, therefore:
- * *incr_block_count <= block_count
+ * *incr_block_count <= block_count
* The caller must be prepared to call this function interatively
* to complete the whole i/o.
* Returns:
* should be read.
*/
boolean_t
-shadow_map_read(shadow_map_t * map, u_long block_offset, u_long block_count,
- u_long * incr_block_offset, u_long * incr_block_count)
+shadow_map_read(shadow_map_t * map, off_t block_offset, size_t block_count,
+ off_t * incr_block_offset, size_t * incr_block_count)
{
- boolean_t written = FALSE;
- u_long n_blocks;
-
- if (block_offset >= map->file_size_blocks
- || (block_offset + block_count) > map->file_size_blocks) {
- printf("shadow_map_read: request (%ld, %ld) exceeds file size %ld\n",
- block_offset, block_count, map->file_size_blocks);
- *incr_block_count = 0;
- }
- n_blocks = bitmap_get(map->block_bitmap, block_offset, block_count,
- &written);
- if (written == FALSE) {
- *incr_block_count = n_blocks;
- *incr_block_offset = block_offset;
- }
- else { /* start has been written, and therefore mapped */
- band_number_t mapped_band;
- u_long band_limit;
-
- mapped_band = map->bands[shadow_map_block_to_band(map, block_offset)];
- *incr_block_offset = mapped_band * map->blocks_per_band
- + (block_offset % map->blocks_per_band);
- band_limit
- = shadow_map_contiguous(map, block_offset, block_count, FALSE);
- *incr_block_count = band_limit - block_offset;
- if (*incr_block_count > n_blocks) {
- *incr_block_count = n_blocks;
+ boolean_t written = FALSE;
+ uint32_t n_blocks;
+
+ if (block_offset >= map->file_size_blocks
+ || (block_offset + block_count) > map->file_size_blocks) {
+ printf("shadow_map_read: request (%lld, %lu) exceeds file size %d\n",
+ block_offset, block_count, map->file_size_blocks);
+ *incr_block_count = 0;
+ }
+ n_blocks = bitmap_get(map->block_bitmap, block_offset, block_count,
+ &written);
+ if (written == FALSE) {
+ *incr_block_count = n_blocks;
+ *incr_block_offset = block_offset;
+ } else { /* start has been written, and therefore mapped */
+ band_number_t mapped_band;
+ off_t band_limit;
+
+ mapped_band = map->bands[shadow_map_block_to_band(map, block_offset)];
+ *incr_block_offset = mapped_band * map->blocks_per_band
+ + (block_offset % map->blocks_per_band);
+ band_limit
+ = shadow_map_contiguous(map, block_offset, block_count, FALSE);
+ *incr_block_count = band_limit - block_offset;
+ if (*incr_block_count > n_blocks) {
+ *incr_block_count = n_blocks;
+ }
}
- }
- return (written);
+ return written;
}
/*
* Purpose:
* Calculate the block offset within the shadow to write, and the number
* blocks to write. The input values (block_offset, block_count) refer
- * to the original file. The output values
+ * to the original file. The output values
* (*incr_block_offset, *incr_block_count) refer to the shadow file.
*
* Bands are not necessarily contiguous, therefore:
- * *incr_block_count <= block_count
+ * *incr_block_count <= block_count
* The caller must be prepared to call this function interatively
* to complete the whole i/o.
* Returns:
- * TRUE if the shadow file was grown, FALSE otherwise.
+ * TRUE if the shadow file was grown, FALSE otherwise.
*/
boolean_t
-shadow_map_write(shadow_map_t * map, u_long block_offset,
- u_long block_count, u_long * incr_block_offset,
- u_long * incr_block_count)
+shadow_map_write(shadow_map_t * map, off_t block_offset,
+ size_t block_count, off_t * incr_block_offset,
+ size_t * incr_block_count)
{
- u_long band_limit;
- band_number_t mapped_band;
- boolean_t shadow_grew = FALSE;
-
- if (block_offset >= map->file_size_blocks
- || (block_offset + block_count) > map->file_size_blocks) {
- printf("shadow_map_write: request (%ld, %ld) exceeds file size %ld\n",
- block_offset, block_count, map->file_size_blocks);
- *incr_block_count = 0;
- }
-
- band_limit = shadow_map_contiguous(map, block_offset, block_count, TRUE);
- mapped_band = map->bands[shadow_map_block_to_band(map, block_offset)];
- *incr_block_offset = mapped_band * map->blocks_per_band
- + (block_offset % map->blocks_per_band);
- *incr_block_count = band_limit - block_offset;
-
- /* mark these blocks as written */
- bitmap_set(map->block_bitmap, block_offset, *incr_block_count);
-
- if (map->next_band > map->shadow_size_bands) {
- map->shadow_size_bands = map->next_band;
- shadow_grew = TRUE;
- }
- return (shadow_grew);
+ off_t band_limit;
+ band_number_t mapped_band;
+ boolean_t shadow_grew = FALSE;
+
+ if (block_offset >= map->file_size_blocks
+ || (block_offset + block_count) > map->file_size_blocks) {
+ printf("shadow_map_write: request (%lld, %zu) exceeds file size %d\n",
+ block_offset, block_count, map->file_size_blocks);
+ *incr_block_count = 0;
+ }
+
+ band_limit = shadow_map_contiguous(map, block_offset, block_count, TRUE);
+ mapped_band = map->bands[shadow_map_block_to_band(map, block_offset)];
+ *incr_block_offset = mapped_band * map->blocks_per_band
+ + (block_offset % map->blocks_per_band);
+ *incr_block_count = band_limit - block_offset;
+
+ /* mark these blocks as written */
+ bitmap_set(map->block_bitmap, block_offset, *incr_block_count);
+
+ if (map->next_band > map->shadow_size_bands) {
+ map->shadow_size_bands = map->next_band;
+ shadow_grew = TRUE;
+ }
+ return shadow_grew;
}
boolean_t
-shadow_map_is_written(shadow_map_t * map, u_long block_offset)
+shadow_map_is_written(shadow_map_t * map, off_t block_offset)
{
- bitmap_offset_t b;
+ bitmap_offset_t b;
- b = bitmap_offset(block_offset);
- return ((map->block_bitmap[b.byte] & bit(b.bit)) ? TRUE : FALSE);
+ b = bitmap_offset(block_offset);
+ return (map->block_bitmap[b.byte] & bit(b.bit)) ? TRUE : FALSE;
}
/*
* Purpose:
* To return the size of the shadow file in blocks.
*/
-u_long
+uint32_t
shadow_map_shadow_size(shadow_map_t * map)
{
- return (map->shadow_size_bands * map->blocks_per_band);
+ return map->shadow_size_bands * map->blocks_per_band;
}
-/*
+/*
* Function: shadow_map_create
*
* Purpose:
* NULL if an error occurred.
*/
shadow_map_t *
-shadow_map_create(off_t file_size, off_t shadow_size,
- u_long band_size, u_long block_size)
+shadow_map_create(off_t file_size, off_t shadow_size,
+ uint32_t band_size, uint32_t block_size)
{
- void * block_bitmap = NULL;
- u_long bitmap_size;
- band_number_t * bands = NULL;
- shadow_map_t * map;
- u_long n_bands = 0;
-
- if (band_size == 0) {
- band_size = BAND_SIZE_DEFAULT;
- }
-
- n_bands = howmany(file_size, band_size);
- if (n_bands > (BAND_MAX + 1)) {
- printf("file is too big: %ld > %d\n",
- n_bands, BAND_MAX);
- goto failure;
- }
-
- /* create a block bitmap, one bit per block */
- bitmap_size = block_bitmap_size(file_size, block_size);
- block_bitmap = my_malloc(bitmap_size);
- if (block_bitmap == NULL) {
- printf("failed to allocate bitmap\n");
- goto failure;
- }
- bzero(block_bitmap, bitmap_size);
-
- /* get the band map */
- bands = (band_number_t *)my_malloc(n_bands * sizeof(band_number_t));
- if (bands == NULL) {
- printf("failed to allocate bands\n");
- goto failure;
- }
- bzero(bands, n_bands * sizeof(band_number_t));
-
- map = my_malloc(sizeof(*map));
- if (map == NULL) {
- printf("failed to allocate map\n");
- goto failure;
- }
- map->blocks_per_band = band_size / block_size;
- map->block_bitmap = block_bitmap;
- map->bands = bands;
- map->file_size_blocks = n_bands * map->blocks_per_band;
- map->next_band = 0;
- map->zeroth_band = -1;
- map->shadow_size_bands = howmany(shadow_size, band_size);
- map->block_size = block_size;
- return (map);
-
- failure:
- if (block_bitmap)
- my_free(block_bitmap);
- if (bands)
- my_free(bands);
- return (NULL);
+ void * block_bitmap = NULL;
+ size_t bitmap_size;
+ band_number_t * bands = NULL;
+ shadow_map_t * map;
+ uint32_t n_bands = 0;
+
+ if (band_size == 0) {
+ band_size = BAND_SIZE_DEFAULT;
+ }
+
+ off_t many = howmany(file_size, band_size);
+ if (many > (BAND_MAX + 1)) {
+ printf("file is too big: %lld > %d\n",
+ many, BAND_MAX);
+ goto failure;
+ }
+ n_bands = (uint32_t)many;
+
+ /* create a block bitmap, one bit per block */
+ bitmap_size = block_bitmap_size(file_size, block_size);
+ block_bitmap = my_malloc(bitmap_size);
+ if (block_bitmap == NULL) {
+ printf("failed to allocate bitmap\n");
+ goto failure;
+ }
+ bzero(block_bitmap, bitmap_size);
+
+ /* get the band map */
+ bands = (band_number_t *)my_malloc(n_bands * sizeof(band_number_t));
+ if (bands == NULL) {
+ printf("failed to allocate bands\n");
+ goto failure;
+ }
+ bzero(bands, n_bands * sizeof(band_number_t));
+
+ map = my_malloc(sizeof(*map));
+ if (map == NULL) {
+ printf("failed to allocate map\n");
+ goto failure;
+ }
+ map->blocks_per_band = band_size / block_size;
+ map->block_bitmap = block_bitmap;
+ map->bands = bands;
+ map->file_size_blocks = n_bands * map->blocks_per_band;
+ map->next_band = 0;
+ map->zeroth_band = -1;
+ map->shadow_size_bands = (uint32_t)howmany(shadow_size, band_size);
+ map->block_size = block_size;
+ return map;
+
+failure:
+ if (block_bitmap) {
+ my_free(block_bitmap);
+ }
+ if (bands) {
+ my_free(bands);
+ }
+ return NULL;
}
/*
*/
void
shadow_map_free(shadow_map_t * map)
-{
- if (map->block_bitmap)
- my_free(map->block_bitmap);
- if (map->bands)
- my_free(map->bands);
- map->block_bitmap = NULL;
- map->bands = NULL;
- my_free(map);
- return;
+{
+ if (map->block_bitmap) {
+ my_free(map->block_bitmap);
+ }
+ if (map->bands) {
+ my_free(map->bands);
+ }
+ map->block_bitmap = NULL;
+ map->bands = NULL;
+ my_free(map);
+ return;
}
#ifdef TEST_SHADOW
-#define BAND_SIZE_BLOCKS (BAND_SIZE_DEFAULT / 512)
+#define BAND_SIZE_BLOCKS (BAND_SIZE_DEFAULT / 512)
enum {
- ReadRequest,
- WriteRequest,
+ ReadRequest,
+ WriteRequest,
};
typedef struct {
- int type;
- u_long offset;
- u_long count;
+ int type;
+ uint32_t offset;
+ uint32_t count;
} block_request_t;
int
main()
{
- shadow_map_t * map;
- int i;
- block_request_t requests[] = {
- { WriteRequest, BAND_SIZE_BLOCKS * 2, 1 },
- { ReadRequest, BAND_SIZE_BLOCKS / 2, BAND_SIZE_BLOCKS * 2 - 2 },
- { WriteRequest, BAND_SIZE_BLOCKS * 1, 5 * BAND_SIZE_BLOCKS + 3},
- { ReadRequest, 0, BAND_SIZE_BLOCKS * 10 },
- { WriteRequest, BAND_SIZE_BLOCKS * (BAND_MAX - 1),
- BAND_SIZE_BLOCKS * 2},
- { 0, 0 },
- };
-
- map = shadow_map_create(1024 * 1024 * 1024 * 8ULL, 0, 0, 512);
- if (map == NULL) {
- printf("shadow_map_create failed\n");
- exit(1);
- }
- for (i = 0; TRUE; i++) {
- u_long offset;
- u_long resid;
- boolean_t shadow_grew;
- boolean_t read_shadow;
-
- if (requests[i].count == 0) {
- break;
+ shadow_map_t * map;
+ int i;
+ block_request_t requests[] = {
+ { WriteRequest, BAND_SIZE_BLOCKS * 2, 1 },
+ { ReadRequest, BAND_SIZE_BLOCKS / 2, BAND_SIZE_BLOCKS * 2 - 2 },
+ { WriteRequest, BAND_SIZE_BLOCKS * 1, 5 * BAND_SIZE_BLOCKS + 3},
+ { ReadRequest, 0, BAND_SIZE_BLOCKS * 10 },
+ { WriteRequest, BAND_SIZE_BLOCKS * (BAND_MAX - 1),
+ BAND_SIZE_BLOCKS * 2},
+ { 0, 0 },
+ };
+
+ map = shadow_map_create(1024 * 1024 * 1024 * 8ULL, 0, 0, 512);
+ if (map == NULL) {
+ printf("shadow_map_create failed\n");
+ exit(1);
}
- offset = requests[i].offset;
- resid = requests[i].count;
- printf("\n%s REQUEST (%ld, %ld)\n",
- requests[i].type == WriteRequest ? "WRITE" : "READ",
- offset, resid);
- switch (requests[i].type) {
- case WriteRequest:
- while (resid > 0) {
- u_long this_offset;
- u_long this_count;
-
- shadow_grew = shadow_map_write(map, offset,
- resid,
- &this_offset,
- &this_count);
- printf("\t(%ld, %ld) => (%ld, %ld)",
- offset, resid, this_offset, this_count);
- resid -= this_count;
- offset += this_count;
- if (shadow_grew) {
- printf(" shadow grew to %ld", shadow_map_shadow_size(map));
+ for (i = 0; TRUE; i++) {
+ uint32_t offset;
+ uint32_t resid;
+ boolean_t shadow_grew;
+ boolean_t read_shadow;
+
+ if (requests[i].count == 0) {
+ break;
}
- printf("\n");
- }
- break;
- case ReadRequest:
- while (resid > 0) {
- u_long this_offset;
- u_long this_count;
-
- read_shadow = shadow_map_read(map, offset,
- resid,
- &this_offset,
- &this_count);
- printf("\t(%ld, %ld) => (%ld, %ld)%s\n",
- offset, resid, this_offset, this_count,
- read_shadow ? " from shadow" : "");
- if (this_count == 0) {
- printf("this_count is 0, aborting\n");
- break;
+ offset = requests[i].offset;
+ resid = requests[i].count;
+ printf("\n%s REQUEST (%ld, %ld)\n",
+ requests[i].type == WriteRequest ? "WRITE" : "READ",
+ offset, resid);
+ switch (requests[i].type) {
+ case WriteRequest:
+ while (resid > 0) {
+ uint32_t this_offset;
+ uint32_t this_count;
+
+ shadow_grew = shadow_map_write(map, offset,
+ resid,
+ &this_offset,
+ &this_count);
+ printf("\t(%ld, %ld) => (%ld, %ld)",
+ offset, resid, this_offset, this_count);
+ resid -= this_count;
+ offset += this_count;
+ if (shadow_grew) {
+ printf(" shadow grew to %ld", shadow_map_shadow_size(map));
+ }
+ printf("\n");
+ }
+ break;
+ case ReadRequest:
+ while (resid > 0) {
+ uint32_t this_offset;
+ uint32_t this_count;
+
+ read_shadow = shadow_map_read(map, offset,
+ resid,
+ &this_offset,
+ &this_count);
+ printf("\t(%ld, %ld) => (%ld, %ld)%s\n",
+ offset, resid, this_offset, this_count,
+ read_shadow ? " from shadow" : "");
+ if (this_count == 0) {
+ printf("this_count is 0, aborting\n");
+ break;
+ }
+ resid -= this_count;
+ offset += this_count;
+ }
+ break;
+ default:
+ break;
}
- resid -= this_count;
- offset += this_count;
- }
- break;
- default:
- break;
}
- }
- if (map) {
- shadow_map_free(map);
- }
- exit(0);
- return (0);
+ if (map) {
+ shadow_map_free(map);
+ }
+ exit(0);
+ return 0;
}
#endif
projects / apple / xnu.git / blobdiff