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-rw-r--r--block.c601
1 files changed, 340 insertions, 261 deletions
diff --git a/block.c b/block.c
index 8946564027..43b0188142 100644
--- a/block.c
+++ b/block.c
@@ -22,43 +22,16 @@
* THE SOFTWARE.
*/
#include "vl.h"
-
-#ifndef _WIN32
-#include <sys/mman.h>
-#endif
-
-#include "cow.h"
-
-struct BlockDriverState {
- int fd; /* if -1, only COW mappings */
- int64_t total_sectors;
- int read_only; /* if true, the media is read only */
- int inserted; /* if true, the media is present */
- int removable; /* if true, the media can be removed */
- int locked; /* if true, the media cannot temporarily be ejected */
- /* event callback when inserting/removing */
- void (*change_cb)(void *opaque);
- void *change_opaque;
-
- uint8_t *cow_bitmap; /* if non NULL, COW mappings are used first */
- uint8_t *cow_bitmap_addr; /* mmap address of cow_bitmap */
- int cow_bitmap_size;
- int cow_fd;
- int64_t cow_sectors_offset;
- int boot_sector_enabled;
- uint8_t boot_sector_data[512];
-
- char filename[1024];
-
- /* NOTE: the following infos are only hints for real hardware
- drivers. They are not used by the block driver */
- int cyls, heads, secs;
- int type;
- char device_name[32];
- BlockDriverState *next;
-};
+#include "block_int.h"
static BlockDriverState *bdrv_first;
+static BlockDriver *first_drv;
+
+void bdrv_register(BlockDriver *bdrv)
+{
+ bdrv->next = first_drv;
+ first_drv = bdrv;
+}
/* create a new block device (by default it is empty) */
BlockDriverState *bdrv_new(const char *device_name)
@@ -69,126 +42,149 @@ BlockDriverState *bdrv_new(const char *device_name)
if(!bs)
return NULL;
pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
- /* insert at the end */
- pbs = &bdrv_first;
- while (*pbs != NULL)
- pbs = &(*pbs)->next;
- *pbs = bs;
+ if (device_name[0] != '\0') {
+ /* insert at the end */
+ pbs = &bdrv_first;
+ while (*pbs != NULL)
+ pbs = &(*pbs)->next;
+ *pbs = bs;
+ }
return bs;
}
-int bdrv_open(BlockDriverState *bs, const char *filename, int snapshot)
+BlockDriver *bdrv_find_format(const char *format_name)
+{
+ BlockDriver *drv1;
+ for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
+ if (!strcmp(drv1->format_name, format_name))
+ return drv1;
+ }
+ return NULL;
+}
+
+int bdrv_create(BlockDriver *drv,
+ const char *filename, int64_t size_in_sectors,
+ const char *backing_file, int flags)
+{
+ if (!drv->bdrv_create)
+ return -ENOTSUP;
+ return drv->bdrv_create(filename, size_in_sectors, backing_file, flags);
+}
+
+/* XXX: race condition possible */
+static void get_tmp_filename(char *filename, int size)
{
int fd;
- int64_t size;
- struct cow_header_v2 cow_header;
-#ifndef _WIN32
- char template[] = "/tmp/vl.XXXXXX";
- int cow_fd;
- struct stat st;
-#endif
+ pstrcpy(filename, size, "/tmp/vl.XXXXXX");
+ fd = mkstemp(filename);
+ close(fd);
+}
- bs->read_only = 0;
- bs->fd = -1;
- bs->cow_fd = -1;
- bs->cow_bitmap = NULL;
- pstrcpy(bs->filename, sizeof(bs->filename), filename);
+static BlockDriver *find_image_format(const char *filename)
+{
+ int fd, ret, score, score_max;
+ BlockDriver *drv1, *drv;
+ uint8_t buf[1024];
- /* open standard HD image */
-#ifdef _WIN32
- fd = open(filename, O_RDWR | O_BINARY);
-#else
- fd = open(filename, O_RDWR | O_LARGEFILE);
-#endif
- if (fd < 0) {
- /* read only image on disk */
-#ifdef _WIN32
- fd = open(filename, O_RDONLY | O_BINARY);
-#else
- fd = open(filename, O_RDONLY | O_LARGEFILE);
-#endif
- if (fd < 0) {
- perror(filename);
- goto fail;
+ fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
+ if (fd < 0)
+ return NULL;
+ ret = read(fd, buf, sizeof(buf));
+ if (ret < 0) {
+ close(fd);
+ return NULL;
+ }
+ close(fd);
+
+ drv = NULL;
+ score_max = 0;
+ for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
+ score = drv1->bdrv_probe(buf, ret, filename);
+ if (score > score_max) {
+ score_max = score;
+ drv = drv1;
}
- if (!snapshot)
- bs->read_only = 1;
}
- bs->fd = fd;
+ return drv;
+}
+
+int bdrv_open(BlockDriverState *bs, const char *filename, int snapshot)
+{
+ return bdrv_open2(bs, filename, snapshot, NULL);
+}
+
+int bdrv_open2(BlockDriverState *bs, const char *filename, int snapshot,
+ BlockDriver *drv)
+{
+ int ret;
+ char tmp_filename[1024];
+
+ bs->read_only = 0;
+ bs->is_temporary = 0;
+ bs->encrypted = 0;
+
+ if (snapshot) {
+ BlockDriverState *bs1;
+ int64_t total_size;
+
+ /* if snapshot, we create a temporary backing file and open it
+ instead of opening 'filename' directly */
- /* see if it is a cow image */
- if (read(fd, &cow_header, sizeof(cow_header)) != sizeof(cow_header)) {
- fprintf(stderr, "%s: could not read header\n", filename);
- goto fail;
+ /* if there is a backing file, use it */
+ bs1 = bdrv_new("");
+ if (!bs1) {
+ return -1;
+ }
+ if (bdrv_open(bs1, filename, 0) < 0) {
+ bdrv_delete(bs1);
+ return -1;
+ }
+ total_size = bs1->total_sectors;
+ bdrv_delete(bs1);
+
+ get_tmp_filename(tmp_filename, sizeof(tmp_filename));
+ /* XXX: use cow for linux as it is more efficient ? */
+ if (bdrv_create(&bdrv_qcow, tmp_filename,
+ total_size, filename, 0) < 0) {
+ return -1;
+ }
+ filename = tmp_filename;
+ bs->is_temporary = 1;
+ }
+
+ pstrcpy(bs->filename, sizeof(bs->filename), filename);
+ if (!drv) {
+ drv = find_image_format(filename);
+ if (!drv)
+ return -1;
+ }
+ bs->drv = drv;
+ bs->opaque = qemu_mallocz(drv->instance_size);
+ if (bs->opaque == NULL && drv->instance_size > 0)
+ return -1;
+
+ ret = drv->bdrv_open(bs, filename);
+ if (ret < 0) {
+ qemu_free(bs->opaque);
+ return -1;
}
#ifndef _WIN32
- if (be32_to_cpu(cow_header.magic) == COW_MAGIC &&
- be32_to_cpu(cow_header.version) == COW_VERSION) {
- /* cow image found */
- size = cow_header.size;
-#ifndef WORDS_BIGENDIAN
- size = bswap64(size);
-#endif
- bs->total_sectors = size / 512;
-
- bs->cow_fd = fd;
- bs->fd = -1;
- if (cow_header.backing_file[0] != '\0') {
- if (stat(cow_header.backing_file, &st) != 0) {
- fprintf(stderr, "%s: could not find original disk image '%s'\n", filename, cow_header.backing_file);
- goto fail;
- }
- if (st.st_mtime != be32_to_cpu(cow_header.mtime)) {
- fprintf(stderr, "%s: original raw disk image '%s' does not match saved timestamp\n", filename, cow_header.backing_file);
- goto fail;
- }
- fd = open(cow_header.backing_file, O_RDONLY | O_LARGEFILE);
- if (fd < 0)
- goto fail;
- bs->fd = fd;
+ if (bs->is_temporary) {
+ unlink(filename);
+ }
+#endif
+ if (bs->backing_file[0] != '\0' && drv->bdrv_is_allocated) {
+ /* if there is a backing file, use it */
+ bs->backing_hd = bdrv_new("");
+ if (!bs->backing_hd) {
+ fail:
+ bdrv_close(bs);
+ return -1;
}
- /* mmap the bitmap */
- bs->cow_bitmap_size = ((bs->total_sectors + 7) >> 3) + sizeof(cow_header);
- bs->cow_bitmap_addr = mmap(get_mmap_addr(bs->cow_bitmap_size),
- bs->cow_bitmap_size,
- PROT_READ | PROT_WRITE,
- MAP_SHARED, bs->cow_fd, 0);
- if (bs->cow_bitmap_addr == MAP_FAILED)
+ if (bdrv_open(bs->backing_hd, bs->backing_file, 0) < 0)
goto fail;
- bs->cow_bitmap = bs->cow_bitmap_addr + sizeof(cow_header);
- bs->cow_sectors_offset = (bs->cow_bitmap_size + 511) & ~511;
- snapshot = 0;
- } else
-#endif
- {
- /* standard raw image */
- size = lseek64(fd, 0, SEEK_END);
- bs->total_sectors = size / 512;
- bs->fd = fd;
}
-#ifndef _WIN32
- if (snapshot) {
- /* create a temporary COW file */
- cow_fd = mkstemp64(template);
- if (cow_fd < 0)
- goto fail;
- bs->cow_fd = cow_fd;
- unlink(template);
-
- /* just need to allocate bitmap */
- bs->cow_bitmap_size = (bs->total_sectors + 7) >> 3;
- bs->cow_bitmap_addr = mmap(get_mmap_addr(bs->cow_bitmap_size),
- bs->cow_bitmap_size,
- PROT_READ | PROT_WRITE,
- MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
- if (bs->cow_bitmap_addr == MAP_FAILED)
- goto fail;
- bs->cow_bitmap = bs->cow_bitmap_addr;
- bs->cow_sectors_offset = 0;
- }
-#endif
-
bs->inserted = 1;
/* call the change callback */
@@ -196,23 +192,22 @@ int bdrv_open(BlockDriverState *bs, const char *filename, int snapshot)
bs->change_cb(bs->change_opaque);
return 0;
- fail:
- bdrv_close(bs);
- return -1;
}
void bdrv_close(BlockDriverState *bs)
{
if (bs->inserted) {
-#ifndef _WIN32
- /* we unmap the mapping so that it is written to the COW file */
- if (bs->cow_bitmap_addr)
- munmap(bs->cow_bitmap_addr, bs->cow_bitmap_size);
+ if (bs->backing_hd)
+ bdrv_delete(bs->backing_hd);
+ bs->drv->bdrv_close(bs);
+ qemu_free(bs->opaque);
+#ifdef _WIN32
+ if (bs->is_temporary) {
+ unlink(bs->filename);
+ }
#endif
- if (bs->cow_fd >= 0)
- close(bs->cow_fd);
- if (bs->fd >= 0)
- close(bs->fd);
+ bs->opaque = NULL;
+ bs->drv = NULL;
bs->inserted = 0;
/* call the change callback */
@@ -223,85 +218,45 @@ void bdrv_close(BlockDriverState *bs)
void bdrv_delete(BlockDriverState *bs)
{
+ /* XXX: remove the driver list */
bdrv_close(bs);
qemu_free(bs);
}
-static inline void set_bit(uint8_t *bitmap, int64_t bitnum)
-{
- bitmap[bitnum / 8] |= (1 << (bitnum%8));
-}
-
-static inline int is_bit_set(const uint8_t *bitmap, int64_t bitnum)
-{
- return !!(bitmap[bitnum / 8] & (1 << (bitnum%8)));
-}
-
-
-/* Return true if first block has been changed (ie. current version is
- * in COW file). Set the number of continuous blocks for which that
- * is true. */
-static int is_changed(uint8_t *bitmap,
- int64_t sector_num, int nb_sectors,
- int *num_same)
-{
- int changed;
-
- if (!bitmap || nb_sectors == 0) {
- *num_same = nb_sectors;
- return 0;
- }
-
- changed = is_bit_set(bitmap, sector_num);
- for (*num_same = 1; *num_same < nb_sectors; (*num_same)++) {
- if (is_bit_set(bitmap, sector_num + *num_same) != changed)
- break;
- }
-
- return changed;
-}
-
/* commit COW file into the raw image */
int bdrv_commit(BlockDriverState *bs)
{
int64_t i;
- uint8_t *cow_bitmap;
+ int n, j;
+ unsigned char sector[512];
if (!bs->inserted)
- return -1;
-
- if (!bs->cow_bitmap) {
- fprintf(stderr, "Already committed to %s\n", bs->filename);
- return 0;
- }
+ return -ENOENT;
if (bs->read_only) {
- fprintf(stderr, "Can't commit to %s: read-only\n", bs->filename);
- return -1;
+ return -EACCES;
}
- cow_bitmap = bs->cow_bitmap;
- for (i = 0; i < bs->total_sectors; i++) {
- if (is_bit_set(cow_bitmap, i)) {
- unsigned char sector[512];
- if (bdrv_read(bs, i, sector, 1) != 0) {
- fprintf(stderr, "Error reading sector %lli: aborting commit\n",
- (long long)i);
- return -1;
- }
+ if (!bs->backing_hd) {
+ return -ENOTSUP;
+ }
- /* Make bdrv_write write to real file for a moment. */
- bs->cow_bitmap = NULL;
- if (bdrv_write(bs, i, sector, 1) != 0) {
- fprintf(stderr, "Error writing sector %lli: aborting commit\n",
- (long long)i);
- bs->cow_bitmap = cow_bitmap;
- return -1;
+ for (i = 0; i < bs->total_sectors;) {
+ if (bs->drv->bdrv_is_allocated(bs, i, 65536, &n)) {
+ for(j = 0; j < n; j++) {
+ if (bdrv_read(bs, i, sector, 1) != 0) {
+ return -EIO;
+ }
+
+ if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
+ return -EIO;
+ }
+ i++;
}
- bs->cow_bitmap = cow_bitmap;
- }
+ } else {
+ i += n;
+ }
}
- fprintf(stderr, "Committed snapshot to %s\n", bs->filename);
return 0;
}
@@ -309,37 +264,34 @@ int bdrv_commit(BlockDriverState *bs)
int bdrv_read(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors)
{
- int ret, n, fd;
- int64_t offset;
-
+ int ret, n;
+ BlockDriver *drv = bs->drv;
+
if (!bs->inserted)
return -1;
while (nb_sectors > 0) {
- if (is_changed(bs->cow_bitmap, sector_num, nb_sectors, &n)) {
- fd = bs->cow_fd;
- offset = bs->cow_sectors_offset;
- } else if (sector_num == 0 && bs->boot_sector_enabled) {
+ if (sector_num == 0 && bs->boot_sector_enabled) {
memcpy(buf, bs->boot_sector_data, 512);
n = 1;
- goto next;
- } else {
- fd = bs->fd;
- offset = 0;
- }
-
- if (fd < 0) {
- /* no file, just return empty sectors */
- memset(buf, 0, n * 512);
+ } else if (bs->backing_hd) {
+ if (drv->bdrv_is_allocated(bs, sector_num, nb_sectors, &n)) {
+ ret = drv->bdrv_read(bs, sector_num, buf, n);
+ if (ret < 0)
+ return -1;
+ } else {
+ /* read from the base image */
+ ret = bdrv_read(bs->backing_hd, sector_num, buf, n);
+ if (ret < 0)
+ return -1;
+ }
} else {
- offset += sector_num * 512;
- lseek64(fd, offset, SEEK_SET);
- ret = read(fd, buf, n * 512);
- if (ret != n * 512) {
+ ret = drv->bdrv_read(bs, sector_num, buf, nb_sectors);
+ if (ret < 0)
return -1;
- }
+ /* no need to loop */
+ break;
}
- next:
nb_sectors -= n;
sector_num += n;
buf += n * 512;
@@ -351,37 +303,11 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num,
int bdrv_write(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors)
{
- int ret, fd, i;
- int64_t offset, retl;
-
if (!bs->inserted)
return -1;
if (bs->read_only)
return -1;
-
- if (bs->cow_bitmap) {
- fd = bs->cow_fd;
- offset = bs->cow_sectors_offset;
- } else {
- fd = bs->fd;
- offset = 0;
- }
-
- offset += sector_num * 512;
- retl = lseek64(fd, offset, SEEK_SET);
- if (retl == -1) {
- return -1;
- }
- ret = write(fd, buf, nb_sectors * 512);
- if (ret != nb_sectors * 512) {
- return -1;
- }
-
- if (bs->cow_bitmap) {
- for (i = 0; i < nb_sectors; i++)
- set_bit(bs->cow_bitmap, sector_num + i);
- }
- return 0;
+ return bs->drv->bdrv_write(bs, sector_num, buf, nb_sectors);
}
void bdrv_get_geometry(BlockDriverState *bs, int64_t *nb_sectors_ptr)
@@ -459,6 +385,47 @@ void bdrv_set_change_cb(BlockDriverState *bs,
bs->change_opaque = opaque;
}
+int bdrv_is_encrypted(BlockDriverState *bs)
+{
+ if (bs->backing_hd && bs->backing_hd->encrypted)
+ return 1;
+ return bs->encrypted;
+}
+
+int bdrv_set_key(BlockDriverState *bs, const char *key)
+{
+ int ret;
+ if (bs->backing_hd && bs->backing_hd->encrypted) {
+ ret = bdrv_set_key(bs->backing_hd, key);
+ if (ret < 0)
+ return ret;
+ if (!bs->encrypted)
+ return 0;
+ }
+ if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
+ return -1;
+ return bs->drv->bdrv_set_key(bs, key);
+}
+
+void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
+{
+ if (!bs->inserted || !bs->drv) {
+ buf[0] = '\0';
+ } else {
+ pstrcpy(buf, buf_size, bs->drv->format_name);
+ }
+}
+
+void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
+ void *opaque)
+{
+ BlockDriver *drv;
+
+ for (drv = first_drv; drv != NULL; drv = drv->next) {
+ it(opaque, drv->format_name);
+ }
+}
+
BlockDriverState *bdrv_find(const char *name)
{
BlockDriverState *bs;
@@ -479,6 +446,11 @@ void bdrv_iterate(void (*it)(void *opaque, const char *name), void *opaque)
}
}
+const char *bdrv_get_device_name(BlockDriverState *bs)
+{
+ return bs->device_name;
+}
+
void bdrv_info(void)
{
BlockDriverState *bs;
@@ -503,10 +475,117 @@ void bdrv_info(void)
}
if (bs->inserted) {
term_printf(" file=%s", bs->filename);
+ if (bs->backing_file[0] != '\0')
+ term_printf(" backing_file=%s", bs->backing_file);
term_printf(" ro=%d", bs->read_only);
+ term_printf(" drv=%s", bs->drv->format_name);
+ if (bs->encrypted)
+ term_printf(" encrypted");
} else {
term_printf(" [not inserted]");
}
term_printf("\n");
}
}
+
+
+/**************************************************************/
+/* RAW block driver */
+
+typedef struct BDRVRawState {
+ int fd;
+} BDRVRawState;
+
+static int raw_probe(const uint8_t *buf, int buf_size, const char *filename)
+{
+ return 1; /* maybe */
+}
+
+static int raw_open(BlockDriverState *bs, const char *filename)
+{
+ BDRVRawState *s = bs->opaque;
+ int fd;
+ int64_t size;
+
+ fd = open(filename, O_RDWR | O_BINARY | O_LARGEFILE);
+ if (fd < 0) {
+ fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE);
+ if (fd < 0)
+ return -1;
+ bs->read_only = 1;
+ }
+ size = lseek64(fd, 0, SEEK_END);
+ bs->total_sectors = size / 512;
+ s->fd = fd;
+ return 0;
+}
+
+static int raw_read(BlockDriverState *bs, int64_t sector_num,
+ uint8_t *buf, int nb_sectors)
+{
+ BDRVRawState *s = bs->opaque;
+ int ret;
+
+ lseek64(s->fd, sector_num * 512, SEEK_SET);
+ ret = read(s->fd, buf, nb_sectors * 512);
+ if (ret != nb_sectors * 512)
+ return -1;
+ return 0;
+}
+
+static int raw_write(BlockDriverState *bs, int64_t sector_num,
+ const uint8_t *buf, int nb_sectors)
+{
+ BDRVRawState *s = bs->opaque;
+ int ret;
+
+ lseek64(s->fd, sector_num * 512, SEEK_SET);
+ ret = write(s->fd, buf, nb_sectors * 512);
+ if (ret != nb_sectors * 512)
+ return -1;
+ return 0;
+}
+
+static int raw_close(BlockDriverState *bs)
+{
+ BDRVRawState *s = bs->opaque;
+ close(s->fd);
+}
+
+static int raw_create(const char *filename, int64_t total_size,
+ const char *backing_file, int flags)
+{
+ int fd;
+
+ if (flags || backing_file)
+ return -ENOTSUP;
+
+ fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY | O_LARGEFILE,
+ 0644);
+ if (fd < 0)
+ return -EIO;
+ ftruncate64(fd, total_size * 512);
+ close(fd);
+ return 0;
+}
+
+BlockDriver bdrv_raw = {
+ "raw",
+ sizeof(BDRVRawState),
+ raw_probe,
+ raw_open,
+ raw_read,
+ raw_write,
+ raw_close,
+ raw_create,
+};
+
+void bdrv_init(void)
+{
+ bdrv_register(&bdrv_raw);
+#ifndef _WIN32
+ bdrv_register(&bdrv_cow);
+#endif
+ bdrv_register(&bdrv_qcow);
+ bdrv_register(&bdrv_vmdk);
+}