From: Ian Jackson Date: Mon, 28 Apr 2008 13:31:17 +0000 (+0100) Subject: block extendable changes found 2008-04-28 X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=5706c60baa2b898b5e4911a5053e5f05cb675e20;p=qemu-xen-unstable.git block extendable changes found 2008-04-28 --- diff --git a/block-qcow.c b/block-qcow.c index 59f1c66c56..c4aea0c531 100644 --- a/block-qcow.c +++ b/block-qcow.c @@ -95,7 +95,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags) int len, i, shift, ret; QCowHeader header; - ret = bdrv_file_open(&s->hd, filename, flags); + ret = bdrv_file_open(&s->hd, filename, flags | BDRV_O_EXTENDABLE); if (ret < 0) return ret; if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) diff --git a/block-qcow2.c b/block-qcow2.c index 9bad090c45..3663362e26 100644 --- a/block-qcow2.c +++ b/block-qcow2.c @@ -191,7 +191,7 @@ static int qcow_open(BlockDriverState *bs, const char *filename, int flags) int len, i, shift, ret; QCowHeader header; - ret = bdrv_file_open(&s->hd, filename, flags); + ret = bdrv_file_open(&s->hd, filename, flags | BDRV_O_EXTENDABLE); if (ret < 0) return ret; if (bdrv_pread(s->hd, 0, &header, sizeof(header)) != sizeof(header)) diff --git a/block-raw-posix.c b/block-raw-posix.c index 45d0a932c8..d57a2d5276 100644 --- a/block-raw-posix.c +++ b/block-raw-posix.c @@ -925,4 +925,6 @@ BlockDriver bdrv_host_device = { .bdrv_set_locked = raw_set_locked, /* generic scsi device */ .bdrv_ioctl = raw_ioctl, + + .bdrv_flags = BLOCK_DRIVER_FLAG_EXTENDABLE }; diff --git a/block-raw-win32.c b/block-raw-win32.c index b86c66e9f2..bbd2e315ca 100644 --- a/block-raw-win32.c +++ b/block-raw-win32.c @@ -549,4 +549,6 @@ BlockDriver bdrv_host_device = { .bdrv_pread = raw_pread, .bdrv_pwrite = raw_pwrite, .bdrv_getlength = raw_getlength, + + .bdrv_flags = BLOCK_DRIVER_FLAG_EXTENDABLE }; diff --git a/block-vmdk.c b/block-vmdk.c index 4cacc6a6ab..e49db6b913 100644 --- a/block-vmdk.c +++ b/block-vmdk.c @@ -378,7 +378,7 @@ static int vmdk_open(BlockDriverState *bs, const char *filename, int flags) flags = BDRV_O_RDONLY; fprintf(stderr, "(VMDK) image open: flags=0x%x filename=%s\n", flags, bs->filename); - ret = bdrv_file_open(&s->hd, filename, flags); + ret = bdrv_file_open(&s->hd, filename, flags | BDRV_O_EXTENDABLE); if (ret < 0) return ret; if (bdrv_pread(s->hd, 0, &magic, sizeof(magic)) != sizeof(magic)) diff --git a/block.c b/block.c index fc32a60c6e..a2515bddcc 100644 --- a/block.c +++ b/block.c @@ -123,6 +123,27 @@ void path_combine(char *dest, int dest_size, } } +static int bdrv_rw_badreq_sectors(BlockDriverState *bs, + int64_t sector_num, int nb_sectors) +{ + return ( + nb_sectors < 0 || + nb_sectors > bs->total_sectors || + sector_num > bs->total_sectors - nb_sectors + ) && !bs->extendable; +} + +static int bdrv_rw_badreq_bytes(BlockDriverState *bs, + int64_t offset, int count) +{ + int64_t size = bs->total_sectors << SECTOR_BITS; + return ( + count < 0 || + count > size || + offset > size - count + ) && !bs->extendable; + +} static void bdrv_register(BlockDriver *bdrv) { @@ -336,6 +357,12 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags, bs->is_temporary = 0; bs->encrypted = 0; + if (flags & BDRV_O_EXTENDABLE) { + if (!(drv->bdrv_flags & BLOCK_DRIVER_FLAG_EXTENDABLE)) + return -ENOSYS; + bs->extendable = 1; + } + if (flags & BDRV_O_SNAPSHOT) { BlockDriverState *bs1; int64_t total_size; @@ -379,6 +406,7 @@ int bdrv_open2(BlockDriverState *bs, const char *filename, int flags, } bs->drv = drv; bs->opaque = qemu_mallocz(drv->instance_size); + bs->total_sectors = 0; /* driver will set if it does not do getlength */ if (bs->opaque == NULL && drv->instance_size > 0) return -1; /* Note: for compatibility, we open disk image files as RDWR, and @@ -444,6 +472,7 @@ void bdrv_close(BlockDriverState *bs) bs->drv = NULL; /* call the change callback */ + bs->total_sectors = 0; bs->media_changed = 1; if (bs->change_cb) bs->change_cb(bs->change_opaque); @@ -509,6 +538,8 @@ int bdrv_read(BlockDriverState *bs, int64_t sector_num, if (!drv) return -ENOMEDIUM; + if (bdrv_rw_badreq_sectors(bs, sector_num, nb_sectors)) + return -EDOM; if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) { memcpy(buf, bs->boot_sector_data, 512); sector_num++; @@ -549,6 +580,8 @@ int bdrv_write(BlockDriverState *bs, int64_t sector_num, return -ENOMEDIUM; if (bs->read_only) return -EACCES; + if (bdrv_rw_badreq_sectors(bs, sector_num, nb_sectors)) + return -EDOM; if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) { memcpy(bs->boot_sector_data, buf, 512); } @@ -674,6 +707,8 @@ int bdrv_pread(BlockDriverState *bs, int64_t offset, return -ENOMEDIUM; if (!drv->bdrv_pread) return bdrv_pread_em(bs, offset, buf1, count1); + if (bdrv_rw_badreq_bytes(bs, offset, count1)) + return -EDOM; return drv->bdrv_pread(bs, offset, buf1, count1); } @@ -689,6 +724,8 @@ int bdrv_pwrite(BlockDriverState *bs, int64_t offset, return -ENOMEDIUM; if (!drv->bdrv_pwrite) return bdrv_pwrite_em(bs, offset, buf1, count1); + if (bdrv_rw_badreq_bytes(bs, offset, count1)) + return -EDOM; return drv->bdrv_pwrite(bs, offset, buf1, count1); } @@ -957,6 +994,8 @@ int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num, return -ENOMEDIUM; if (!drv->bdrv_write_compressed) return -ENOTSUP; + if (bdrv_rw_badreq_sectors(bs, sector_num, nb_sectors)) + return -EDOM; return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors); } @@ -1103,6 +1142,8 @@ BlockDriverAIOCB *bdrv_aio_read(BlockDriverState *bs, int64_t sector_num, if (!drv) return NULL; + if (bdrv_rw_badreq_sectors(bs, sector_num, nb_sectors)) + return NULL; /* XXX: we assume that nb_sectors == 0 is suppored by the async read */ if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) { @@ -1134,6 +1175,8 @@ BlockDriverAIOCB *bdrv_aio_write(BlockDriverState *bs, int64_t sector_num, return NULL; if (bs->read_only) return NULL; + if (bdrv_rw_badreq_sectors(bs, sector_num, nb_sectors)) + return NULL; if (sector_num == 0 && bs->boot_sector_enabled && nb_sectors > 0) { memcpy(bs->boot_sector_data, buf, 512); } diff --git a/block.h b/block.h index 861a65b180..2dfabda1b1 100644 --- a/block.h +++ b/block.h @@ -45,6 +45,8 @@ typedef struct QEMUSnapshotInfo { it (default for bdrv_file_open()) */ #define BDRV_O_DIRECT 0x0020 +#define BDRV_O_EXTENDABLE 0x0080 /* allow writes out of original size range; + only effective for some drivers */ #ifndef QEMU_IMG void bdrv_info(void); diff --git a/block_int.h b/block_int.h index 796ce294ff..c752344c47 100644 --- a/block_int.h +++ b/block_int.h @@ -30,6 +30,8 @@ #define BLOCK_FLAG_COMPRESS 2 #define BLOCK_FLAG_COMPAT6 4 +#define BLOCK_DRIVER_FLAG_EXTENDABLE 0x0001u + struct BlockDriver { const char *format_name; int instance_size; @@ -85,6 +87,7 @@ struct BlockDriver { /* to control generic scsi devices */ int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf); + unsigned bdrv_flags; BlockDriverAIOCB *free_aiocb; struct BlockDriver *next; }; @@ -97,6 +100,7 @@ struct BlockDriverState { int locked; /* if true, the media cannot temporarily be ejected */ int encrypted; /* if true, the media is encrypted */ int sg; /* if true, the device is a /dev/sg* */ + int extendable;/* if true, we may write out of original range */ /* event callback when inserting/removing */ void (*change_cb)(void *opaque); void *change_opaque;