[mirror_qemu.git] / block.c

/*
 * QEMU System Emulator block driver
 * 
 * Copyright (c) 2003 Fabrice Bellard
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include <stdlib.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <getopt.h>
#include <inttypes.h>
#include <unistd.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <signal.h>
#include <time.h>
#include <sys/time.h>
#include <malloc.h>
#include <termios.h>
#include <sys/poll.h>
#include <errno.h>
#include <sys/wait.h>
#include <netinet/in.h>

#include "vl.h"

#define NO_THUNK_TYPE_SIZE
#include "thunk.h"

#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;
};

static BlockDriverState *bdrv_first;

/* create a new block device (by default it is empty) */
BlockDriverState *bdrv_new(const char *device_name)
{
    BlockDriverState **pbs, *bs;

    bs = qemu_mallocz(sizeof(BlockDriverState));
    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;
    return bs;
}

int bdrv_open(BlockDriverState *bs, const char *filename, int snapshot)
{
    int fd, cow_fd;
    int64_t size;
    char template[] = "/tmp/vl.XXXXXX";
    struct cow_header_v2 cow_header;
    struct stat st;

    bs->read_only = 0;
    bs->fd = -1;
    bs->cow_fd = -1;
    bs->cow_bitmap = NULL;
    strcpy(bs->filename, filename);

    /* open standard HD image */
    fd = open(filename, O_RDWR | O_LARGEFILE);
    if (fd < 0) {
        /* read only image on disk */
        fd = open(filename, O_RDONLY | O_LARGEFILE);
        if (fd < 0) {
            perror(filename);
            goto fail;
        }
        if (!snapshot)
            bs->read_only = 1;
    }
    bs->fd = fd;

    /* 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 (cow_header.magic == htonl(COW_MAGIC) &&
        cow_header.version == htonl(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 != htonl(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;
        }
        /* 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)
            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 {
        /* standard raw image */
        size = lseek64(fd, 0, SEEK_END);
        bs->total_sectors = size / 512;
        bs->fd = fd;
    }

    if (snapshot) {
        /* create a temporary COW file */
        cow_fd = mkstemp(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;
    }
    
    bs->inserted = 1;

    /* call the change callback */
    if (bs->change_cb)
        bs->change_cb(bs->change_opaque);

    return 0;
 fail:
    bdrv_close(bs);
    return -1;
}

void bdrv_close(BlockDriverState *bs)
{
    if (bs->inserted) {
        /* 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->cow_fd >= 0)
            close(bs->cow_fd);
        if (bs->fd >= 0)
            close(bs->fd);
        bs->inserted = 0;

        /* call the change callback */
        if (bs->change_cb)
            bs->change_cb(bs->change_opaque);
    }
}

void bdrv_delete(BlockDriverState *bs)
{
    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;

    if (!bs->inserted)
        return -1;

    if (!bs->cow_bitmap) {
	fprintf(stderr, "Already committed to %s\n", bs->filename);
	return 0;
    }

    if (bs->read_only) {
	fprintf(stderr, "Can't commit to %s: read-only\n", bs->filename);
	return -1;
    }

    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;
	    }

	    /* 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;
	    }
	    bs->cow_bitmap = cow_bitmap;
	}
    }
    fprintf(stderr, "Committed snapshot to %s\n", bs->filename);
    return 0;
}

/* return -1 if error */
int bdrv_read(BlockDriverState *bs, int64_t sector_num, 
              uint8_t *buf, int nb_sectors)
{
    int ret, n, fd;
    int64_t offset;
    
    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) {
            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 {
            offset += sector_num * 512;
            lseek64(fd, offset, SEEK_SET);
            ret = read(fd, buf, n * 512);
            if (ret != n * 512) {
                return -1;
            }
        }
    next:
        nb_sectors -= n;
        sector_num += n;
        buf += n * 512;
    }
    return 0;
}

/* return -1 if error */
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;
}

void bdrv_get_geometry(BlockDriverState *bs, int64_t *nb_sectors_ptr)
{
    *nb_sectors_ptr = bs->total_sectors;
}

/* force a given boot sector. */
void bdrv_set_boot_sector(BlockDriverState *bs, const uint8_t *data, int size)
{
    bs->boot_sector_enabled = 1;
    if (size > 512)
        size = 512;
    memcpy(bs->boot_sector_data, data, size);
    memset(bs->boot_sector_data + size, 0, 512 - size);
}

void bdrv_set_geometry_hint(BlockDriverState *bs, 
                            int cyls, int heads, int secs)
{
    bs->cyls = cyls;
    bs->heads = heads;
    bs->secs = secs;
}

void bdrv_set_type_hint(BlockDriverState *bs, int type)
{
    bs->type = type;
    bs->removable = ((type == BDRV_TYPE_CDROM ||
                      type == BDRV_TYPE_FLOPPY));
}

void bdrv_get_geometry_hint(BlockDriverState *bs, 
                            int *pcyls, int *pheads, int *psecs)
{
    *pcyls = bs->cyls;
    *pheads = bs->heads;
    *psecs = bs->secs;
}

int bdrv_get_type_hint(BlockDriverState *bs)
{
    return bs->type;
}

int bdrv_is_removable(BlockDriverState *bs)
{
    return bs->removable;
}

int bdrv_is_read_only(BlockDriverState *bs)
{
    return bs->read_only;
}

int bdrv_is_inserted(BlockDriverState *bs)
{
    return bs->inserted;
}

int bdrv_is_locked(BlockDriverState *bs)
{
    return bs->locked;
}

void bdrv_set_locked(BlockDriverState *bs, int locked)
{
    bs->locked = locked;
}

void bdrv_set_change_cb(BlockDriverState *bs, 
                        void (*change_cb)(void *opaque), void *opaque)
{
    bs->change_cb = change_cb;
    bs->change_opaque = opaque;
}

BlockDriverState *bdrv_find(const char *name)
{
    BlockDriverState *bs;

    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
        if (!strcmp(name, bs->device_name))
            return bs;
    }
    return NULL;
}

void bdrv_info(void)
{
    BlockDriverState *bs;

    for (bs = bdrv_first; bs != NULL; bs = bs->next) {
        term_printf("%s:", bs->device_name);
        term_printf(" type=");
        switch(bs->type) {
        case BDRV_TYPE_HD:
            term_printf("hd");
            break;
        case BDRV_TYPE_CDROM:
            term_printf("cdrom");
            break;
        case BDRV_TYPE_FLOPPY:
            term_printf("floppy");
            break;
        }
        term_printf(" removable=%d", bs->removable);
        if (bs->removable) {
            term_printf(" locked=%d", bs->locked);
        }
        if (bs->inserted) {
            term_printf(" file=%s", bs->filename);
            term_printf(" ro=%d", bs->read_only);
        } else {
            term_printf(" [not inserted]");
        }
        term_printf("\n");
    }
}
Commit	Line	Data
fc01f7e7 FB	1	/*
	2	* QEMU System Emulator block driver
	3	*
	4	* Copyright (c) 2003 Fabrice Bellard
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	22	* THE SOFTWARE.
	23	*/
	24	#include <stdlib.h>
	25	#include <stdio.h>
	26	#include <stdarg.h>
	27	#include <string.h>
	28	#include <getopt.h>
	29	#include <inttypes.h>
	30	#include <unistd.h>
	31	#include <sys/mman.h>
	32	#include <fcntl.h>
	33	#include <signal.h>
	34	#include <time.h>
	35	#include <sys/time.h>
	36	#include <malloc.h>
	37	#include <termios.h>
	38	#include <sys/poll.h>
	39	#include <errno.h>
	40	#include <sys/wait.h>
33e3963e	41	#include <netinet/in.h>
fc01f7e7 FB	42
	43	#include "vl.h"
	44
33e3963e FB	45	#define NO_THUNK_TYPE_SIZE
	46	#include "thunk.h"
	47
00af2b26 FB	48	#include "cow.h"
00af2b26 FB	49
fc01f7e7	50	struct BlockDriverState {
33e3963e	51	int fd; /* if -1, only COW mappings */
fc01f7e7	52	int64_t total_sectors;
b338082b FB	53	int read_only; /* if true, the media is read only */
	54	int inserted; /* if true, the media is present */
	55	int removable; /* if true, the media can be removed */
	56	int locked; /* if true, the media cannot temporarily be ejected */
	57	/* event callback when inserting/removing */
	58	void (change_cb)(void opaque);
	59	void *change_opaque;
33e3963e FB	60
	61	uint8_t cow_bitmap; / if non NULL, COW mappings are used first */
	62	uint8_t cow_bitmap_addr; / mmap address of cow_bitmap */
	63	int cow_bitmap_size;
	64	int cow_fd;
	65	int64_t cow_sectors_offset;
cf98951b FB	66	int boot_sector_enabled;
	67	uint8_t boot_sector_data[512];
	68
33e3963e	69	char filename[1024];
b338082b FB	70
	71	/* NOTE: the following infos are only hints for real hardware
	72	drivers. They are not used by the block driver */
	73	int cyls, heads, secs;
	74	int type;
	75	char device_name[32];
	76	BlockDriverState *next;
fc01f7e7 FB	77	};
fc01f7e7 FB	78
b338082b FB	79	static BlockDriverState *bdrv_first;
	80
	81	/* create a new block device (by default it is empty) */
	82	BlockDriverState bdrv_new(const char device_name)
	83	{
	84	BlockDriverState *pbs, bs;
	85
	86	bs = qemu_mallocz(sizeof(BlockDriverState));
	87	if(!bs)
	88	return NULL;
	89	pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
	90	/* insert at the end */
	91	pbs = &bdrv_first;
	92	while (*pbs != NULL)
	93	pbs = &(*pbs)->next;
	94	*pbs = bs;
	95	return bs;
	96	}
	97
	98	int bdrv_open(BlockDriverState bs, const char filename, int snapshot)
fc01f7e7	99	{
33e3963e	100	int fd, cow_fd;
fc01f7e7	101	int64_t size;
33e3963e FB	102	char template[] = "/tmp/vl.XXXXXX";
	103	struct cow_header_v2 cow_header;
	104	struct stat st;
fc01f7e7	105
0849bf08	106	bs->read_only = 0;
33e3963e FB	107	bs->fd = -1;
	108	bs->cow_fd = -1;
	109	bs->cow_bitmap = NULL;
	110	strcpy(bs->filename, filename);
	111
	112	/* open standard HD image */
	113	fd = open(filename, O_RDWR \| O_LARGEFILE);
fc01f7e7	114	if (fd < 0) {
33e3963e FB	115	/* read only image on disk */
33e3963e FB	116	fd = open(filename, O_RDONLY \| O_LARGEFILE);
0849bf08	117	if (fd < 0) {
33e3963e FB	118	perror(filename);
33e3963e FB	119	goto fail;
0849bf08	120	}
33e3963e FB	121	if (!snapshot)
33e3963e FB	122	bs->read_only = 1;
fc01f7e7	123	}
fc01f7e7	124	bs->fd = fd;
33e3963e FB	125
	126	/* see if it is a cow image */
	127	if (read(fd, &cow_header, sizeof(cow_header)) != sizeof(cow_header)) {
	128	fprintf(stderr, "%s: could not read header\n", filename);
	129	goto fail;
	130	}
	131	if (cow_header.magic == htonl(COW_MAGIC) &&
	132	cow_header.version == htonl(COW_VERSION)) {
	133	/* cow image found */
	134	size = cow_header.size;
	135	#ifndef WORDS_BIGENDIAN
	136	size = bswap64(size);
	137	#endif
	138	bs->total_sectors = size / 512;
	139
	140	bs->cow_fd = fd;
	141	bs->fd = -1;
	142	if (cow_header.backing_file[0] != '\0') {
	143	if (stat(cow_header.backing_file, &st) != 0) {
	144	fprintf(stderr, "%s: could not find original disk image '%s'\n", filename, cow_header.backing_file);
	145	goto fail;
	146	}
	147	if (st.st_mtime != htonl(cow_header.mtime)) {
	148	fprintf(stderr, "%s: original raw disk image '%s' does not match saved timestamp\n", filename, cow_header.backing_file);
	149	goto fail;
	150	}
	151	fd = open(cow_header.backing_file, O_RDONLY \| O_LARGEFILE);
	152	if (fd < 0)
	153	goto fail;
	154	bs->fd = fd;
	155	}
	156	/* mmap the bitmap */
	157	bs->cow_bitmap_size = ((bs->total_sectors + 7) >> 3) + sizeof(cow_header);
	158	bs->cow_bitmap_addr = mmap(get_mmap_addr(bs->cow_bitmap_size),
	159	bs->cow_bitmap_size,
	160	PROT_READ \| PROT_WRITE,
	161	MAP_SHARED, bs->cow_fd, 0);
	162	if (bs->cow_bitmap_addr == MAP_FAILED)
	163	goto fail;
	164	bs->cow_bitmap = bs->cow_bitmap_addr + sizeof(cow_header);
	165	bs->cow_sectors_offset = (bs->cow_bitmap_size + 511) & ~511;
	166	snapshot = 0;
	167	} else {
	168	/* standard raw image */
	169	size = lseek64(fd, 0, SEEK_END);
	170	bs->total_sectors = size / 512;
	171	bs->fd = fd;
	172	}
	173
	174	if (snapshot) {
	175	/* create a temporary COW file */
	176	cow_fd = mkstemp(template);
	177	if (cow_fd < 0)
	178	goto fail;
	179	bs->cow_fd = cow_fd;
	180	unlink(template);
	181
	182	/* just need to allocate bitmap */
	183	bs->cow_bitmap_size = (bs->total_sectors + 7) >> 3;
	184	bs->cow_bitmap_addr = mmap(get_mmap_addr(bs->cow_bitmap_size),
	185	bs->cow_bitmap_size,
	186	PROT_READ \| PROT_WRITE,
	187	MAP_PRIVATE \| MAP_ANONYMOUS, -1, 0);
	188	if (bs->cow_bitmap_addr == MAP_FAILED)
189	goto fail;
190	bs->cow_bitmap = bs->cow_bitmap_addr;
191	bs->cow_sectors_offset = 0;
192	}
193
b338082b FB	194	bs->inserted = 1;
	195
	196	/* call the change callback */
	197	if (bs->change_cb)
	198	bs->change_cb(bs->change_opaque);
	199
	200	return 0;
33e3963e FB	201	fail:
33e3963e FB	202	bdrv_close(bs);
b338082b	203	return -1;
fc01f7e7 FB	204	}
	205
	206	void bdrv_close(BlockDriverState *bs)
	207	{
b338082b FB	208	if (bs->inserted) {
	209	/* we unmap the mapping so that it is written to the COW file */
	210	if (bs->cow_bitmap_addr)
	211	munmap(bs->cow_bitmap_addr, bs->cow_bitmap_size);
	212	if (bs->cow_fd >= 0)
	213	close(bs->cow_fd);
	214	if (bs->fd >= 0)
	215	close(bs->fd);
	216	bs->inserted = 0;
	217
	218	/* call the change callback */
	219	if (bs->change_cb)
	220	bs->change_cb(bs->change_opaque);
	221	}
	222	}
	223
	224	void bdrv_delete(BlockDriverState *bs)
	225	{
	226	bdrv_close(bs);
	227	qemu_free(bs);
fc01f7e7 FB	228	}
fc01f7e7 FB	229
33e3963e FB	230	static inline void set_bit(uint8_t *bitmap, int64_t bitnum)
	231	{
	232	bitmap[bitnum / 8] \|= (1 << (bitnum%8));
	233	}
	234
	235	static inline int is_bit_set(const uint8_t *bitmap, int64_t bitnum)
	236	{
	237	return !!(bitmap[bitnum / 8] & (1 << (bitnum%8)));
	238	}
	239
	240
	241	/* Return true if first block has been changed (ie. current version is
	242	* in COW file). Set the number of continuous blocks for which that
	243	* is true. */
	244	static int is_changed(uint8_t *bitmap,
	245	int64_t sector_num, int nb_sectors,
	246	int *num_same)
	247	{
	248	int changed;
	249
	250	if (!bitmap \|\| nb_sectors == 0) {
	251	*num_same = nb_sectors;
	252	return 0;
	253	}
	254
	255	changed = is_bit_set(bitmap, sector_num);
	256	for (num_same = 1; num_same < nb_sectors; (*num_same)++) {
	257	if (is_bit_set(bitmap, sector_num + *num_same) != changed)
	258	break;
	259	}
	260
	261	return changed;
	262	}
	263
	264	/* commit COW file into the raw image */
	265	int bdrv_commit(BlockDriverState *bs)
	266	{
	267	int64_t i;
	268	uint8_t *cow_bitmap;
	269
b338082b FB	270	if (!bs->inserted)
	271	return -1;
	272
33e3963e FB	273	if (!bs->cow_bitmap) {
	274	fprintf(stderr, "Already committed to %s\n", bs->filename);
	275	return 0;
	276	}
	277
	278	if (bs->read_only) {
	279	fprintf(stderr, "Can't commit to %s: read-only\n", bs->filename);
	280	return -1;
	281	}
	282
	283	cow_bitmap = bs->cow_bitmap;
	284	for (i = 0; i < bs->total_sectors; i++) {
	285	if (is_bit_set(cow_bitmap, i)) {
	286	unsigned char sector[512];
	287	if (bdrv_read(bs, i, sector, 1) != 0) {
	288	fprintf(stderr, "Error reading sector %lli: aborting commit\n",
	289	(long long)i);
	290	return -1;
	291	}
	292
	293	/* Make bdrv_write write to real file for a moment. */
	294	bs->cow_bitmap = NULL;
	295	if (bdrv_write(bs, i, sector, 1) != 0) {
	296	fprintf(stderr, "Error writing sector %lli: aborting commit\n",
	297	(long long)i);
	298	bs->cow_bitmap = cow_bitmap;
	299	return -1;
	300	}
	301	bs->cow_bitmap = cow_bitmap;
	302	}
	303	}
	304	fprintf(stderr, "Committed snapshot to %s\n", bs->filename);
	305	return 0;
	306	}
	307
fc01f7e7 FB	308	/* return -1 if error */
	309	int bdrv_read(BlockDriverState *bs, int64_t sector_num,
	310	uint8_t *buf, int nb_sectors)
	311	{
33e3963e FB	312	int ret, n, fd;
	313	int64_t offset;
	314
b338082b FB	315	if (!bs->inserted)
	316	return -1;
	317
33e3963e FB	318	while (nb_sectors > 0) {
	319	if (is_changed(bs->cow_bitmap, sector_num, nb_sectors, &n)) {
	320	fd = bs->cow_fd;
	321	offset = bs->cow_sectors_offset;
cf98951b FB	322	} else if (sector_num == 0 && bs->boot_sector_enabled) {
	323	memcpy(buf, bs->boot_sector_data, 512);
	324	n = 1;
	325	goto next;
33e3963e FB	326	} else {
	327	fd = bs->fd;
	328	offset = 0;
	329	}
fc01f7e7	330
33e3963e FB	331	if (fd < 0) {
	332	/* no file, just return empty sectors */
	333	memset(buf, 0, n * 512);
	334	} else {
	335	offset += sector_num * 512;
	336	lseek64(fd, offset, SEEK_SET);
	337	ret = read(fd, buf, n * 512);
	338	if (ret != n * 512) {
	339	return -1;
	340	}
	341	}
cf98951b	342	next:
33e3963e FB	343	nb_sectors -= n;
	344	sector_num += n;
	345	buf += n * 512;
	346	}
	347	return 0;
fc01f7e7 FB	348	}
	349
	350	/* return -1 if error */
	351	int bdrv_write(BlockDriverState *bs, int64_t sector_num,
	352	const uint8_t *buf, int nb_sectors)
	353	{
33e3963e FB	354	int ret, fd, i;
33e3963e FB	355	int64_t offset, retl;
cf98951b	356
b338082b FB	357	if (!bs->inserted)
b338082b FB	358	return -1;
0849bf08 FB	359	if (bs->read_only)
	360	return -1;
	361
33e3963e FB	362	if (bs->cow_bitmap) {
	363	fd = bs->cow_fd;
	364	offset = bs->cow_sectors_offset;
	365	} else {
	366	fd = bs->fd;
	367	offset = 0;
	368	}
	369
	370	offset += sector_num * 512;
	371	retl = lseek64(fd, offset, SEEK_SET);
	372	if (retl == -1) {
fc01f7e7	373	return -1;
33e3963e FB	374	}
	375	ret = write(fd, buf, nb_sectors * 512);
	376	if (ret != nb_sectors * 512) {
	377	return -1;
	378	}
	379
	380	if (bs->cow_bitmap) {
	381	for (i = 0; i < nb_sectors; i++)
	382	set_bit(bs->cow_bitmap, sector_num + i);
	383	}
	384	return 0;
fc01f7e7 FB	385	}
	386
	387	void bdrv_get_geometry(BlockDriverState bs, int64_t nb_sectors_ptr)
	388	{
	389	*nb_sectors_ptr = bs->total_sectors;
	390	}
cf98951b FB	391
	392	/* force a given boot sector. */
	393	void bdrv_set_boot_sector(BlockDriverState bs, const uint8_t data, int size)
	394	{
	395	bs->boot_sector_enabled = 1;
	396	if (size > 512)
	397	size = 512;
	398	memcpy(bs->boot_sector_data, data, size);
	399	memset(bs->boot_sector_data + size, 0, 512 - size);
	400	}
b338082b FB	401
	402	void bdrv_set_geometry_hint(BlockDriverState *bs,
	403	int cyls, int heads, int secs)
	404	{
	405	bs->cyls = cyls;
	406	bs->heads = heads;
	407	bs->secs = secs;
	408	}
	409
	410	void bdrv_set_type_hint(BlockDriverState *bs, int type)
	411	{
	412	bs->type = type;
	413	bs->removable = ((type == BDRV_TYPE_CDROM \|\|
	414	type == BDRV_TYPE_FLOPPY));
	415	}
	416
	417	void bdrv_get_geometry_hint(BlockDriverState *bs,
	418	int pcyls, int pheads, int *psecs)
	419	{
	420	*pcyls = bs->cyls;
	421	*pheads = bs->heads;
	422	*psecs = bs->secs;
	423	}
	424
	425	int bdrv_get_type_hint(BlockDriverState *bs)
	426	{
	427	return bs->type;
	428	}
	429
	430	int bdrv_is_removable(BlockDriverState *bs)
	431	{
	432	return bs->removable;
	433	}
	434
	435	int bdrv_is_read_only(BlockDriverState *bs)
	436	{
	437	return bs->read_only;
	438	}
	439
	440	int bdrv_is_inserted(BlockDriverState *bs)
	441	{
	442	return bs->inserted;
	443	}
	444
	445	int bdrv_is_locked(BlockDriverState *bs)
	446	{
	447	return bs->locked;
	448	}
	449
	450	void bdrv_set_locked(BlockDriverState *bs, int locked)
	451	{
	452	bs->locked = locked;
	453	}
	454
	455	void bdrv_set_change_cb(BlockDriverState *bs,
	456	void (change_cb)(void opaque), void *opaque)
	457	{
	458	bs->change_cb = change_cb;
	459	bs->change_opaque = opaque;
	460	}
	461
	462	BlockDriverState bdrv_find(const char name)
	463	{
	464	BlockDriverState *bs;
465
466	for (bs = bdrv_first; bs != NULL; bs = bs->next) {
467	if (!strcmp(name, bs->device_name))
468	return bs;
469	}
470	return NULL;
471	}
472
473	void bdrv_info(void)
474	{
475	BlockDriverState *bs;
476
477	for (bs = bdrv_first; bs != NULL; bs = bs->next) {
478	term_printf("%s:", bs->device_name);
479	term_printf(" type=");
480	switch(bs->type) {
481	case BDRV_TYPE_HD:
482	term_printf("hd");
483	break;
484	case BDRV_TYPE_CDROM:
485	term_printf("cdrom");
486	break;
487	case BDRV_TYPE_FLOPPY:
488	term_printf("floppy");
489	break;
490	}
491	term_printf(" removable=%d", bs->removable);
492	if (bs->removable) {
493	term_printf(" locked=%d", bs->locked);
494	}
495	if (bs->inserted) {
496	term_printf(" file=%s", bs->filename);
497	term_printf(" ro=%d", bs->read_only);
498	} else {
499	term_printf(" [not inserted]");
500	}
501	term_printf("\n");
502	}
503	}