qemu/block_int.h
Markus Armbruster 4be9762adb block: Change bdrv_eject() not to drop the image
bdrv_eject() gets called when a device model opens or closes the tray.

If the block driver implements method bdrv_eject(), that method gets
called.  Drivers host_cdrom implements it, and it opens and closes the
physical tray, and nothing else.  When a device model opens, then
closes the tray, media changes only if the user actively changes the
physical media while the tray is open.  This is matches how physical
hardware behaves.

If the block driver doesn't implement method bdrv_eject(), we do
something quite different: opening the tray severs the connection to
the image by calling bdrv_close(), and closing the tray does nothing.
When the device model opens, then closes the tray, media is gone,
unless the user actively inserts another one while the tray is open,
with a suitable change command in the monitor.  This isn't how
physical hardware behaves.  Rather inconvenient when programs
"helpfully" eject media to give you a chance to change it.  The way
bdrv_eject() behaves here turns that chance into a must, which is not
what these programs or their users expect.

Change the default action not to call bdrv_close().  Instead, note the
tray status in new BlockDriverState member tray_open.  Use it in
bdrv_is_inserted().

Arguably, the device models should keep track of tray status
themselves.  But this is less invasive.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2010-08-03 15:57:22 +02:00

254 lines
9.3 KiB
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.
*/
#ifndef BLOCK_INT_H
#define BLOCK_INT_H
#include "block.h"
#include "qemu-option.h"
#include "qemu-queue.h"
#define BLOCK_FLAG_ENCRYPT 1
#define BLOCK_FLAG_COMPRESS 2
#define BLOCK_FLAG_COMPAT6 4
#define BLOCK_OPT_SIZE "size"
#define BLOCK_OPT_ENCRYPT "encryption"
#define BLOCK_OPT_COMPAT6 "compat6"
#define BLOCK_OPT_BACKING_FILE "backing_file"
#define BLOCK_OPT_BACKING_FMT "backing_fmt"
#define BLOCK_OPT_CLUSTER_SIZE "cluster_size"
#define BLOCK_OPT_PREALLOC "preallocation"
typedef struct AIOPool {
void (*cancel)(BlockDriverAIOCB *acb);
int aiocb_size;
BlockDriverAIOCB *free_aiocb;
} AIOPool;
struct BlockDriver {
const char *format_name;
int instance_size;
int (*bdrv_probe)(const uint8_t *buf, int buf_size, const char *filename);
int (*bdrv_probe_device)(const char *filename);
int (*bdrv_open)(BlockDriverState *bs, int flags);
int (*bdrv_file_open)(BlockDriverState *bs, const char *filename, int flags);
int (*bdrv_read)(BlockDriverState *bs, int64_t sector_num,
uint8_t *buf, int nb_sectors);
int (*bdrv_write)(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors);
void (*bdrv_close)(BlockDriverState *bs);
int (*bdrv_create)(const char *filename, QEMUOptionParameter *options);
void (*bdrv_flush)(BlockDriverState *bs);
int (*bdrv_is_allocated)(BlockDriverState *bs, int64_t sector_num,
int nb_sectors, int *pnum);
int (*bdrv_set_key)(BlockDriverState *bs, const char *key);
int (*bdrv_make_empty)(BlockDriverState *bs);
/* aio */
BlockDriverAIOCB *(*bdrv_aio_readv)(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
BlockDriverAIOCB *(*bdrv_aio_writev)(BlockDriverState *bs,
int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
BlockDriverCompletionFunc *cb, void *opaque);
BlockDriverAIOCB *(*bdrv_aio_flush)(BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque);
int (*bdrv_aio_multiwrite)(BlockDriverState *bs, BlockRequest *reqs,
int num_reqs);
int (*bdrv_merge_requests)(BlockDriverState *bs, BlockRequest* a,
BlockRequest *b);
const char *protocol_name;
int (*bdrv_truncate)(BlockDriverState *bs, int64_t offset);
int64_t (*bdrv_getlength)(BlockDriverState *bs);
int (*bdrv_write_compressed)(BlockDriverState *bs, int64_t sector_num,
const uint8_t *buf, int nb_sectors);
int (*bdrv_snapshot_create)(BlockDriverState *bs,
QEMUSnapshotInfo *sn_info);
int (*bdrv_snapshot_goto)(BlockDriverState *bs,
const char *snapshot_id);
int (*bdrv_snapshot_delete)(BlockDriverState *bs, const char *snapshot_id);
int (*bdrv_snapshot_list)(BlockDriverState *bs,
QEMUSnapshotInfo **psn_info);
int (*bdrv_get_info)(BlockDriverState *bs, BlockDriverInfo *bdi);
int (*bdrv_save_vmstate)(BlockDriverState *bs, const uint8_t *buf,
int64_t pos, int size);
int (*bdrv_load_vmstate)(BlockDriverState *bs, uint8_t *buf,
int64_t pos, int size);
int (*bdrv_change_backing_file)(BlockDriverState *bs,
const char *backing_file, const char *backing_fmt);
/* removable device specific */
int (*bdrv_is_inserted)(BlockDriverState *bs);
int (*bdrv_media_changed)(BlockDriverState *bs);
int (*bdrv_eject)(BlockDriverState *bs, int eject_flag);
int (*bdrv_set_locked)(BlockDriverState *bs, int locked);
/* to control generic scsi devices */
int (*bdrv_ioctl)(BlockDriverState *bs, unsigned long int req, void *buf);
BlockDriverAIOCB *(*bdrv_aio_ioctl)(BlockDriverState *bs,
unsigned long int req, void *buf,
BlockDriverCompletionFunc *cb, void *opaque);
/* List of options for creating images, terminated by name == NULL */
QEMUOptionParameter *create_options;
/*
* Returns 0 for completed check, -errno for internal errors.
* The check results are stored in result.
*/
int (*bdrv_check)(BlockDriverState* bs, BdrvCheckResult *result);
void (*bdrv_debug_event)(BlockDriverState *bs, BlkDebugEvent event);
/*
* Returns 1 if newly created images are guaranteed to contain only
* zeros, 0 otherwise.
*/
int (*bdrv_has_zero_init)(BlockDriverState *bs);
QLIST_ENTRY(BlockDriver) list;
};
struct BlockDriverState {
int64_t total_sectors; /* if we are reading a disk image, give its
size in sectors */
int read_only; /* if true, the media is read only */
int keep_read_only; /* if true, the media was requested to stay read only */
int open_flags; /* flags used to open the file, re-used for re-open */
int removable; /* if true, the media can be removed */
int locked; /* if true, the media cannot temporarily be ejected */
int tray_open; /* if true, the virtual tray is open */
int encrypted; /* if true, the media is encrypted */
int valid_key; /* if true, a valid encryption key has been set */
int sg; /* if true, the device is a /dev/sg* */
int probed; /* if true, format was probed automatically */
/* event callback when inserting/removing */
void (*change_cb)(void *opaque);
void *change_opaque;
BlockDriver *drv; /* NULL means no media */
void *opaque;
DeviceState *peer;
char filename[1024];
char backing_file[1024]; /* if non zero, the image is a diff of
this file image */
char backing_format[16]; /* if non-zero and backing_file exists */
int is_temporary;
int media_changed;
BlockDriverState *backing_hd;
BlockDriverState *file;
/* async read/write emulation */
void *sync_aiocb;
/* I/O stats (display with "info blockstats"). */
uint64_t rd_bytes;
uint64_t wr_bytes;
uint64_t rd_ops;
uint64_t wr_ops;
uint64_t wr_highest_sector;
/* Whether the disk can expand beyond total_sectors */
int growable;
/* the memory alignment required for the buffers handled by this driver */
int buffer_alignment;
/* do we need to tell the quest if we have a volatile write cache? */
int enable_write_cache;
/* NOTE: the following infos are only hints for real hardware
drivers. They are not used by the block driver */
int cyls, heads, secs, translation;
int type;
BlockErrorAction on_read_error, on_write_error;
char device_name[32];
unsigned long *dirty_bitmap;
int64_t dirty_count;
QTAILQ_ENTRY(BlockDriverState) list;
void *private;
};
struct BlockDriverAIOCB {
AIOPool *pool;
BlockDriverState *bs;
BlockDriverCompletionFunc *cb;
void *opaque;
BlockDriverAIOCB *next;
};
void get_tmp_filename(char *filename, int size);
void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
BlockDriverCompletionFunc *cb, void *opaque);
void qemu_aio_release(void *p);
void *qemu_blockalign(BlockDriverState *bs, size_t size);
#ifdef _WIN32
int is_windows_drive(const char *filename);
#endif
typedef struct BlockConf {
BlockDriverState *bs;
uint16_t physical_block_size;
uint16_t logical_block_size;
uint16_t min_io_size;
uint32_t opt_io_size;
} BlockConf;
static inline unsigned int get_physical_block_exp(BlockConf *conf)
{
unsigned int exp = 0, size;
for (size = conf->physical_block_size;
size > conf->logical_block_size;
size >>= 1) {
exp++;
}
return exp;
}
#define DEFINE_BLOCK_PROPERTIES(_state, _conf) \
DEFINE_PROP_DRIVE("drive", _state, _conf.bs), \
DEFINE_PROP_UINT16("logical_block_size", _state, \
_conf.logical_block_size, 512), \
DEFINE_PROP_UINT16("physical_block_size", _state, \
_conf.physical_block_size, 512), \
DEFINE_PROP_UINT16("min_io_size", _state, _conf.min_io_size, 0), \
DEFINE_PROP_UINT32("opt_io_size", _state, _conf.opt_io_size, 0)
#endif /* BLOCK_INT_H */