diff options
Diffstat (limited to 'src/block/block-backend.c')
| -rw-r--r-- | src/block/block-backend.c | 1284 |
1 files changed, 1284 insertions, 0 deletions
diff --git a/src/block/block-backend.c b/src/block/block-backend.c new file mode 100644 index 0000000..419591f --- /dev/null +++ b/src/block/block-backend.c @@ -0,0 +1,1284 @@ +/* + * QEMU Block backends + * + * Copyright (C) 2014 Red Hat, Inc. + * + * Authors: + * Markus Armbruster <armbru@redhat.com>, + * + * This work is licensed under the terms of the GNU LGPL, version 2.1 + * or later. See the COPYING.LIB file in the top-level directory. + */ + +#include "sysemu/block-backend.h" +#include "block/block_int.h" +#include "block/blockjob.h" +#include "block/throttle-groups.h" +#include "sysemu/blockdev.h" +#include "sysemu/sysemu.h" +#include "qapi-event.h" + +/* Number of coroutines to reserve per attached device model */ +#define COROUTINE_POOL_RESERVATION 64 + +static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb); + +struct BlockBackend { + char *name; + int refcnt; + BlockDriverState *bs; + DriveInfo *legacy_dinfo; /* null unless created by drive_new() */ + QTAILQ_ENTRY(BlockBackend) link; /* for blk_backends */ + + void *dev; /* attached device model, if any */ + /* TODO change to DeviceState when all users are qdevified */ + const BlockDevOps *dev_ops; + void *dev_opaque; + + /* the block size for which the guest device expects atomicity */ + int guest_block_size; + + /* If the BDS tree is removed, some of its options are stored here (which + * can be used to restore those options in the new BDS on insert) */ + BlockBackendRootState root_state; + + /* I/O stats (display with "info blockstats"). */ + BlockAcctStats stats; + + BlockdevOnError on_read_error, on_write_error; + bool iostatus_enabled; + BlockDeviceIoStatus iostatus; +}; + +typedef struct BlockBackendAIOCB { + BlockAIOCB common; + QEMUBH *bh; + BlockBackend *blk; + int ret; +} BlockBackendAIOCB; + +static const AIOCBInfo block_backend_aiocb_info = { + .get_aio_context = blk_aiocb_get_aio_context, + .aiocb_size = sizeof(BlockBackendAIOCB), +}; + +static void drive_info_del(DriveInfo *dinfo); + +/* All the BlockBackends (except for hidden ones) */ +static QTAILQ_HEAD(, BlockBackend) blk_backends = + QTAILQ_HEAD_INITIALIZER(blk_backends); + +/* + * Create a new BlockBackend with @name, with a reference count of one. + * @name must not be null or empty. + * Fail if a BlockBackend with this name already exists. + * Store an error through @errp on failure, unless it's null. + * Return the new BlockBackend on success, null on failure. + */ +BlockBackend *blk_new(const char *name, Error **errp) +{ + BlockBackend *blk; + + assert(name && name[0]); + if (!id_wellformed(name)) { + error_setg(errp, "Invalid device name"); + return NULL; + } + if (blk_by_name(name)) { + error_setg(errp, "Device with id '%s' already exists", name); + return NULL; + } + if (bdrv_find_node(name)) { + error_setg(errp, + "Device name '%s' conflicts with an existing node name", + name); + return NULL; + } + + blk = g_new0(BlockBackend, 1); + blk->name = g_strdup(name); + blk->refcnt = 1; + QTAILQ_INSERT_TAIL(&blk_backends, blk, link); + return blk; +} + +/* + * Create a new BlockBackend with a new BlockDriverState attached. + * Otherwise just like blk_new(), which see. + */ +BlockBackend *blk_new_with_bs(const char *name, Error **errp) +{ + BlockBackend *blk; + BlockDriverState *bs; + + blk = blk_new(name, errp); + if (!blk) { + return NULL; + } + + bs = bdrv_new_root(); + blk->bs = bs; + bs->blk = blk; + return blk; +} + +/* + * Calls blk_new_with_bs() and then calls bdrv_open() on the BlockDriverState. + * + * Just as with bdrv_open(), after having called this function the reference to + * @options belongs to the block layer (even on failure). + * + * TODO: Remove @filename and @flags; it should be possible to specify a whole + * BDS tree just by specifying the @options QDict (or @reference, + * alternatively). At the time of adding this function, this is not possible, + * though, so callers of this function have to be able to specify @filename and + * @flags. + */ +BlockBackend *blk_new_open(const char *name, const char *filename, + const char *reference, QDict *options, int flags, + Error **errp) +{ + BlockBackend *blk; + int ret; + + blk = blk_new_with_bs(name, errp); + if (!blk) { + QDECREF(options); + return NULL; + } + + ret = bdrv_open(&blk->bs, filename, reference, options, flags, errp); + if (ret < 0) { + blk_unref(blk); + return NULL; + } + + return blk; +} + +static void blk_delete(BlockBackend *blk) +{ + assert(!blk->refcnt); + assert(!blk->dev); + if (blk->bs) { + assert(blk->bs->blk == blk); + blk->bs->blk = NULL; + bdrv_unref(blk->bs); + blk->bs = NULL; + } + if (blk->root_state.throttle_state) { + g_free(blk->root_state.throttle_group); + throttle_group_unref(blk->root_state.throttle_state); + } + /* Avoid double-remove after blk_hide_on_behalf_of_hmp_drive_del() */ + if (blk->name[0]) { + QTAILQ_REMOVE(&blk_backends, blk, link); + } + g_free(blk->name); + drive_info_del(blk->legacy_dinfo); + block_acct_cleanup(&blk->stats); + g_free(blk); +} + +static void drive_info_del(DriveInfo *dinfo) +{ + if (!dinfo) { + return; + } + qemu_opts_del(dinfo->opts); + g_free(dinfo->serial); + g_free(dinfo); +} + +int blk_get_refcnt(BlockBackend *blk) +{ + return blk ? blk->refcnt : 0; +} + +/* + * Increment @blk's reference count. + * @blk must not be null. + */ +void blk_ref(BlockBackend *blk) +{ + blk->refcnt++; +} + +/* + * Decrement @blk's reference count. + * If this drops it to zero, destroy @blk. + * For convenience, do nothing if @blk is null. + */ +void blk_unref(BlockBackend *blk) +{ + if (blk) { + assert(blk->refcnt > 0); + if (!--blk->refcnt) { + blk_delete(blk); + } + } +} + +/* + * Return the BlockBackend after @blk. + * If @blk is null, return the first one. + * Else, return @blk's next sibling, which may be null. + * + * To iterate over all BlockBackends, do + * for (blk = blk_next(NULL); blk; blk = blk_next(blk)) { + * ... + * } + */ +BlockBackend *blk_next(BlockBackend *blk) +{ + return blk ? QTAILQ_NEXT(blk, link) : QTAILQ_FIRST(&blk_backends); +} + +/* + * Return @blk's name, a non-null string. + * Wart: the name is empty iff @blk has been hidden with + * blk_hide_on_behalf_of_hmp_drive_del(). + */ +const char *blk_name(BlockBackend *blk) +{ + return blk->name; +} + +/* + * Return the BlockBackend with name @name if it exists, else null. + * @name must not be null. + */ +BlockBackend *blk_by_name(const char *name) +{ + BlockBackend *blk; + + assert(name); + QTAILQ_FOREACH(blk, &blk_backends, link) { + if (!strcmp(name, blk->name)) { + return blk; + } + } + return NULL; +} + +/* + * Return the BlockDriverState attached to @blk if any, else null. + */ +BlockDriverState *blk_bs(BlockBackend *blk) +{ + return blk->bs; +} + +/* + * Changes the BlockDriverState attached to @blk + */ +void blk_set_bs(BlockBackend *blk, BlockDriverState *bs) +{ + bdrv_ref(bs); + + if (blk->bs) { + blk->bs->blk = NULL; + bdrv_unref(blk->bs); + } + assert(bs->blk == NULL); + + blk->bs = bs; + bs->blk = blk; +} + +/* + * Return @blk's DriveInfo if any, else null. + */ +DriveInfo *blk_legacy_dinfo(BlockBackend *blk) +{ + return blk->legacy_dinfo; +} + +/* + * Set @blk's DriveInfo to @dinfo, and return it. + * @blk must not have a DriveInfo set already. + * No other BlockBackend may have the same DriveInfo set. + */ +DriveInfo *blk_set_legacy_dinfo(BlockBackend *blk, DriveInfo *dinfo) +{ + assert(!blk->legacy_dinfo); + return blk->legacy_dinfo = dinfo; +} + +/* + * Return the BlockBackend with DriveInfo @dinfo. + * It must exist. + */ +BlockBackend *blk_by_legacy_dinfo(DriveInfo *dinfo) +{ + BlockBackend *blk; + + QTAILQ_FOREACH(blk, &blk_backends, link) { + if (blk->legacy_dinfo == dinfo) { + return blk; + } + } + abort(); +} + +/* + * Hide @blk. + * @blk must not have been hidden already. + * Make attached BlockDriverState, if any, anonymous. + * Once hidden, @blk is invisible to all functions that don't receive + * it as argument. For example, blk_by_name() won't return it. + * Strictly for use by do_drive_del(). + * TODO get rid of it! + */ +void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk) +{ + QTAILQ_REMOVE(&blk_backends, blk, link); + blk->name[0] = 0; + if (blk->bs) { + bdrv_make_anon(blk->bs); + } +} + +/* + * Disassociates the currently associated BlockDriverState from @blk. + */ +void blk_remove_bs(BlockBackend *blk) +{ + blk_update_root_state(blk); + + blk->bs->blk = NULL; + bdrv_unref(blk->bs); + blk->bs = NULL; +} + +/* + * Associates a new BlockDriverState with @blk. + */ +void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs) +{ + assert(!blk->bs && !bs->blk); + bdrv_ref(bs); + blk->bs = bs; + bs->blk = blk; +} + +/* + * Attach device model @dev to @blk. + * Return 0 on success, -EBUSY when a device model is attached already. + */ +int blk_attach_dev(BlockBackend *blk, void *dev) +/* TODO change to DeviceState *dev when all users are qdevified */ +{ + if (blk->dev) { + return -EBUSY; + } + blk_ref(blk); + blk->dev = dev; + blk_iostatus_reset(blk); + return 0; +} + +/* + * Attach device model @dev to @blk. + * @blk must not have a device model attached already. + * TODO qdevified devices don't use this, remove when devices are qdevified + */ +void blk_attach_dev_nofail(BlockBackend *blk, void *dev) +{ + if (blk_attach_dev(blk, dev) < 0) { + abort(); + } +} + +/* + * Detach device model @dev from @blk. + * @dev must be currently attached to @blk. + */ +void blk_detach_dev(BlockBackend *blk, void *dev) +/* TODO change to DeviceState *dev when all users are qdevified */ +{ + assert(blk->dev == dev); + blk->dev = NULL; + blk->dev_ops = NULL; + blk->dev_opaque = NULL; + blk->guest_block_size = 512; + blk_unref(blk); +} + +/* + * Return the device model attached to @blk if any, else null. + */ +void *blk_get_attached_dev(BlockBackend *blk) +/* TODO change to return DeviceState * when all users are qdevified */ +{ + return blk->dev; +} + +/* + * Set @blk's device model callbacks to @ops. + * @opaque is the opaque argument to pass to the callbacks. + * This is for use by device models. + */ +void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, + void *opaque) +{ + blk->dev_ops = ops; + blk->dev_opaque = opaque; +} + +/* + * Notify @blk's attached device model of media change. + * If @load is true, notify of media load. + * Else, notify of media eject. + * Also send DEVICE_TRAY_MOVED events as appropriate. + */ +void blk_dev_change_media_cb(BlockBackend *blk, bool load) +{ + if (blk->dev_ops && blk->dev_ops->change_media_cb) { + bool tray_was_open, tray_is_open; + + tray_was_open = blk_dev_is_tray_open(blk); + blk->dev_ops->change_media_cb(blk->dev_opaque, load); + tray_is_open = blk_dev_is_tray_open(blk); + + if (tray_was_open != tray_is_open) { + qapi_event_send_device_tray_moved(blk_name(blk), tray_is_open, + &error_abort); + } + } +} + +/* + * Does @blk's attached device model have removable media? + * %true if no device model is attached. + */ +bool blk_dev_has_removable_media(BlockBackend *blk) +{ + return !blk->dev || (blk->dev_ops && blk->dev_ops->change_media_cb); +} + +/* + * Does @blk's attached device model have a tray? + */ +bool blk_dev_has_tray(BlockBackend *blk) +{ + return blk->dev_ops && blk->dev_ops->is_tray_open; +} + +/* + * Notify @blk's attached device model of a media eject request. + * If @force is true, the medium is about to be yanked out forcefully. + */ +void blk_dev_eject_request(BlockBackend *blk, bool force) +{ + if (blk->dev_ops && blk->dev_ops->eject_request_cb) { + blk->dev_ops->eject_request_cb(blk->dev_opaque, force); + } +} + +/* + * Does @blk's attached device model have a tray, and is it open? + */ +bool blk_dev_is_tray_open(BlockBackend *blk) +{ + if (blk_dev_has_tray(blk)) { + return blk->dev_ops->is_tray_open(blk->dev_opaque); + } + return false; +} + +/* + * Does @blk's attached device model have the medium locked? + * %false if the device model has no such lock. + */ +bool blk_dev_is_medium_locked(BlockBackend *blk) +{ + if (blk->dev_ops && blk->dev_ops->is_medium_locked) { + return blk->dev_ops->is_medium_locked(blk->dev_opaque); + } + return false; +} + +/* + * Notify @blk's attached device model of a backend size change. + */ +void blk_dev_resize_cb(BlockBackend *blk) +{ + if (blk->dev_ops && blk->dev_ops->resize_cb) { + blk->dev_ops->resize_cb(blk->dev_opaque); + } +} + +void blk_iostatus_enable(BlockBackend *blk) +{ + blk->iostatus_enabled = true; + blk->iostatus = BLOCK_DEVICE_IO_STATUS_OK; +} + +/* The I/O status is only enabled if the drive explicitly + * enables it _and_ the VM is configured to stop on errors */ +bool blk_iostatus_is_enabled(const BlockBackend *blk) +{ + return (blk->iostatus_enabled && + (blk->on_write_error == BLOCKDEV_ON_ERROR_ENOSPC || + blk->on_write_error == BLOCKDEV_ON_ERROR_STOP || + blk->on_read_error == BLOCKDEV_ON_ERROR_STOP)); +} + +BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk) +{ + return blk->iostatus; +} + +void blk_iostatus_disable(BlockBackend *blk) +{ + blk->iostatus_enabled = false; +} + +void blk_iostatus_reset(BlockBackend *blk) +{ + if (blk_iostatus_is_enabled(blk)) { + blk->iostatus = BLOCK_DEVICE_IO_STATUS_OK; + if (blk->bs && blk->bs->job) { + block_job_iostatus_reset(blk->bs->job); + } + } +} + +void blk_iostatus_set_err(BlockBackend *blk, int error) +{ + assert(blk_iostatus_is_enabled(blk)); + if (blk->iostatus == BLOCK_DEVICE_IO_STATUS_OK) { + blk->iostatus = error == ENOSPC ? BLOCK_DEVICE_IO_STATUS_NOSPACE : + BLOCK_DEVICE_IO_STATUS_FAILED; + } +} + +static int blk_check_byte_request(BlockBackend *blk, int64_t offset, + size_t size) +{ + int64_t len; + + if (size > INT_MAX) { + return -EIO; + } + + if (!blk_is_available(blk)) { + return -ENOMEDIUM; + } + + len = blk_getlength(blk); + if (len < 0) { + return len; + } + + if (offset < 0) { + return -EIO; + } + + if (offset > len || len - offset < size) { + return -EIO; + } + + return 0; +} + +static int blk_check_request(BlockBackend *blk, int64_t sector_num, + int nb_sectors) +{ + if (sector_num < 0 || sector_num > INT64_MAX / BDRV_SECTOR_SIZE) { + return -EIO; + } + + if (nb_sectors < 0 || nb_sectors > INT_MAX / BDRV_SECTOR_SIZE) { + return -EIO; + } + + return blk_check_byte_request(blk, sector_num * BDRV_SECTOR_SIZE, + nb_sectors * BDRV_SECTOR_SIZE); +} + +int blk_read(BlockBackend *blk, int64_t sector_num, uint8_t *buf, + int nb_sectors) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return ret; + } + + return bdrv_read(blk->bs, sector_num, buf, nb_sectors); +} + +int blk_read_unthrottled(BlockBackend *blk, int64_t sector_num, uint8_t *buf, + int nb_sectors) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return ret; + } + + return bdrv_read_unthrottled(blk->bs, sector_num, buf, nb_sectors); +} + +int blk_write(BlockBackend *blk, int64_t sector_num, const uint8_t *buf, + int nb_sectors) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return ret; + } + + return bdrv_write(blk->bs, sector_num, buf, nb_sectors); +} + +int blk_write_zeroes(BlockBackend *blk, int64_t sector_num, + int nb_sectors, BdrvRequestFlags flags) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return ret; + } + + return bdrv_write_zeroes(blk->bs, sector_num, nb_sectors, flags); +} + +static void error_callback_bh(void *opaque) +{ + struct BlockBackendAIOCB *acb = opaque; + qemu_bh_delete(acb->bh); + acb->common.cb(acb->common.opaque, acb->ret); + qemu_aio_unref(acb); +} + +BlockAIOCB *blk_abort_aio_request(BlockBackend *blk, + BlockCompletionFunc *cb, + void *opaque, int ret) +{ + struct BlockBackendAIOCB *acb; + QEMUBH *bh; + + acb = blk_aio_get(&block_backend_aiocb_info, blk, cb, opaque); + acb->blk = blk; + acb->ret = ret; + + bh = aio_bh_new(blk_get_aio_context(blk), error_callback_bh, acb); + acb->bh = bh; + qemu_bh_schedule(bh); + + return &acb->common; +} + +BlockAIOCB *blk_aio_write_zeroes(BlockBackend *blk, int64_t sector_num, + int nb_sectors, BdrvRequestFlags flags, + BlockCompletionFunc *cb, void *opaque) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return blk_abort_aio_request(blk, cb, opaque, ret); + } + + return bdrv_aio_write_zeroes(blk->bs, sector_num, nb_sectors, flags, + cb, opaque); +} + +int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int count) +{ + int ret = blk_check_byte_request(blk, offset, count); + if (ret < 0) { + return ret; + } + + return bdrv_pread(blk->bs, offset, buf, count); +} + +int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int count) +{ + int ret = blk_check_byte_request(blk, offset, count); + if (ret < 0) { + return ret; + } + + return bdrv_pwrite(blk->bs, offset, buf, count); +} + +int64_t blk_getlength(BlockBackend *blk) +{ + if (!blk_is_available(blk)) { + return -ENOMEDIUM; + } + + return bdrv_getlength(blk->bs); +} + +void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr) +{ + if (!blk->bs) { + *nb_sectors_ptr = 0; + } else { + bdrv_get_geometry(blk->bs, nb_sectors_ptr); + } +} + +int64_t blk_nb_sectors(BlockBackend *blk) +{ + if (!blk_is_available(blk)) { + return -ENOMEDIUM; + } + + return bdrv_nb_sectors(blk->bs); +} + +BlockAIOCB *blk_aio_readv(BlockBackend *blk, int64_t sector_num, + QEMUIOVector *iov, int nb_sectors, + BlockCompletionFunc *cb, void *opaque) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return blk_abort_aio_request(blk, cb, opaque, ret); + } + + return bdrv_aio_readv(blk->bs, sector_num, iov, nb_sectors, cb, opaque); +} + +BlockAIOCB *blk_aio_writev(BlockBackend *blk, int64_t sector_num, + QEMUIOVector *iov, int nb_sectors, + BlockCompletionFunc *cb, void *opaque) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return blk_abort_aio_request(blk, cb, opaque, ret); + } + + return bdrv_aio_writev(blk->bs, sector_num, iov, nb_sectors, cb, opaque); +} + +BlockAIOCB *blk_aio_flush(BlockBackend *blk, + BlockCompletionFunc *cb, void *opaque) +{ + if (!blk_is_available(blk)) { + return blk_abort_aio_request(blk, cb, opaque, -ENOMEDIUM); + } + + return bdrv_aio_flush(blk->bs, cb, opaque); +} + +BlockAIOCB *blk_aio_discard(BlockBackend *blk, + int64_t sector_num, int nb_sectors, + BlockCompletionFunc *cb, void *opaque) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return blk_abort_aio_request(blk, cb, opaque, ret); + } + + return bdrv_aio_discard(blk->bs, sector_num, nb_sectors, cb, opaque); +} + +void blk_aio_cancel(BlockAIOCB *acb) +{ + bdrv_aio_cancel(acb); +} + +void blk_aio_cancel_async(BlockAIOCB *acb) +{ + bdrv_aio_cancel_async(acb); +} + +int blk_aio_multiwrite(BlockBackend *blk, BlockRequest *reqs, int num_reqs) +{ + int i, ret; + + for (i = 0; i < num_reqs; i++) { + ret = blk_check_request(blk, reqs[i].sector, reqs[i].nb_sectors); + if (ret < 0) { + return ret; + } + } + + return bdrv_aio_multiwrite(blk->bs, reqs, num_reqs); +} + +int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf) +{ + if (!blk_is_available(blk)) { + return -ENOMEDIUM; + } + + return bdrv_ioctl(blk->bs, req, buf); +} + +BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf, + BlockCompletionFunc *cb, void *opaque) +{ + if (!blk_is_available(blk)) { + return blk_abort_aio_request(blk, cb, opaque, -ENOMEDIUM); + } + + return bdrv_aio_ioctl(blk->bs, req, buf, cb, opaque); +} + +int blk_co_discard(BlockBackend *blk, int64_t sector_num, int nb_sectors) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return ret; + } + + return bdrv_co_discard(blk->bs, sector_num, nb_sectors); +} + +int blk_co_flush(BlockBackend *blk) +{ + if (!blk_is_available(blk)) { + return -ENOMEDIUM; + } + + return bdrv_co_flush(blk->bs); +} + +int blk_flush(BlockBackend *blk) +{ + if (!blk_is_available(blk)) { + return -ENOMEDIUM; + } + + return bdrv_flush(blk->bs); +} + +int blk_flush_all(void) +{ + return bdrv_flush_all(); +} + +void blk_drain(BlockBackend *blk) +{ + if (blk->bs) { + bdrv_drain(blk->bs); + } +} + +void blk_drain_all(void) +{ + bdrv_drain_all(); +} + +void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error, + BlockdevOnError on_write_error) +{ + blk->on_read_error = on_read_error; + blk->on_write_error = on_write_error; +} + +BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read) +{ + return is_read ? blk->on_read_error : blk->on_write_error; +} + +BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read, + int error) +{ + BlockdevOnError on_err = blk_get_on_error(blk, is_read); + + switch (on_err) { + case BLOCKDEV_ON_ERROR_ENOSPC: + return (error == ENOSPC) ? + BLOCK_ERROR_ACTION_STOP : BLOCK_ERROR_ACTION_REPORT; + case BLOCKDEV_ON_ERROR_STOP: + return BLOCK_ERROR_ACTION_STOP; + case BLOCKDEV_ON_ERROR_REPORT: + return BLOCK_ERROR_ACTION_REPORT; + case BLOCKDEV_ON_ERROR_IGNORE: + return BLOCK_ERROR_ACTION_IGNORE; + default: + abort(); + } +} + +static void send_qmp_error_event(BlockBackend *blk, + BlockErrorAction action, + bool is_read, int error) +{ + IoOperationType optype; + + optype = is_read ? IO_OPERATION_TYPE_READ : IO_OPERATION_TYPE_WRITE; + qapi_event_send_block_io_error(blk_name(blk), optype, action, + blk_iostatus_is_enabled(blk), + error == ENOSPC, strerror(error), + &error_abort); +} + +/* This is done by device models because, while the block layer knows + * about the error, it does not know whether an operation comes from + * the device or the block layer (from a job, for example). + */ +void blk_error_action(BlockBackend *blk, BlockErrorAction action, + bool is_read, int error) +{ + assert(error >= 0); + + if (action == BLOCK_ERROR_ACTION_STOP) { + /* First set the iostatus, so that "info block" returns an iostatus + * that matches the events raised so far (an additional error iostatus + * is fine, but not a lost one). + */ + blk_iostatus_set_err(blk, error); + + /* Then raise the request to stop the VM and the event. + * qemu_system_vmstop_request_prepare has two effects. First, + * it ensures that the STOP event always comes after the + * BLOCK_IO_ERROR event. Second, it ensures that even if management + * can observe the STOP event and do a "cont" before the STOP + * event is issued, the VM will not stop. In this case, vm_start() + * also ensures that the STOP/RESUME pair of events is emitted. + */ + qemu_system_vmstop_request_prepare(); + send_qmp_error_event(blk, action, is_read, error); + qemu_system_vmstop_request(RUN_STATE_IO_ERROR); + } else { + send_qmp_error_event(blk, action, is_read, error); + } +} + +int blk_is_read_only(BlockBackend *blk) +{ + if (blk->bs) { + return bdrv_is_read_only(blk->bs); + } else { + return blk->root_state.read_only; + } +} + +int blk_is_sg(BlockBackend *blk) +{ + if (!blk->bs) { + return 0; + } + + return bdrv_is_sg(blk->bs); +} + +int blk_enable_write_cache(BlockBackend *blk) +{ + if (blk->bs) { + return bdrv_enable_write_cache(blk->bs); + } else { + return !!(blk->root_state.open_flags & BDRV_O_CACHE_WB); + } +} + +void blk_set_enable_write_cache(BlockBackend *blk, bool wce) +{ + if (blk->bs) { + bdrv_set_enable_write_cache(blk->bs, wce); + } else { + if (wce) { + blk->root_state.open_flags |= BDRV_O_CACHE_WB; + } else { + blk->root_state.open_flags &= ~BDRV_O_CACHE_WB; + } + } +} + +void blk_invalidate_cache(BlockBackend *blk, Error **errp) +{ + if (!blk->bs) { + error_setg(errp, "Device '%s' has no medium", blk->name); + return; + } + + bdrv_invalidate_cache(blk->bs, errp); +} + +bool blk_is_inserted(BlockBackend *blk) +{ + return blk->bs && bdrv_is_inserted(blk->bs); +} + +bool blk_is_available(BlockBackend *blk) +{ + return blk_is_inserted(blk) && !blk_dev_is_tray_open(blk); +} + +void blk_lock_medium(BlockBackend *blk, bool locked) +{ + if (blk->bs) { + bdrv_lock_medium(blk->bs, locked); + } +} + +void blk_eject(BlockBackend *blk, bool eject_flag) +{ + if (blk->bs) { + bdrv_eject(blk->bs, eject_flag); + } +} + +int blk_get_flags(BlockBackend *blk) +{ + if (blk->bs) { + return bdrv_get_flags(blk->bs); + } else { + return blk->root_state.open_flags; + } +} + +int blk_get_max_transfer_length(BlockBackend *blk) +{ + if (blk->bs) { + return blk->bs->bl.max_transfer_length; + } else { + return 0; + } +} + +void blk_set_guest_block_size(BlockBackend *blk, int align) +{ + blk->guest_block_size = align; +} + +void *blk_blockalign(BlockBackend *blk, size_t size) +{ + return qemu_blockalign(blk ? blk->bs : NULL, size); +} + +bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp) +{ + if (!blk->bs) { + return false; + } + + return bdrv_op_is_blocked(blk->bs, op, errp); +} + +void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason) +{ + if (blk->bs) { + bdrv_op_unblock(blk->bs, op, reason); + } +} + +void blk_op_block_all(BlockBackend *blk, Error *reason) +{ + if (blk->bs) { + bdrv_op_block_all(blk->bs, reason); + } +} + +void blk_op_unblock_all(BlockBackend *blk, Error *reason) +{ + if (blk->bs) { + bdrv_op_unblock_all(blk->bs, reason); + } +} + +AioContext *blk_get_aio_context(BlockBackend *blk) +{ + if (blk->bs) { + return bdrv_get_aio_context(blk->bs); + } else { + return qemu_get_aio_context(); + } +} + +static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb) +{ + BlockBackendAIOCB *blk_acb = DO_UPCAST(BlockBackendAIOCB, common, acb); + return blk_get_aio_context(blk_acb->blk); +} + +void blk_set_aio_context(BlockBackend *blk, AioContext *new_context) +{ + if (blk->bs) { + bdrv_set_aio_context(blk->bs, new_context); + } +} + +void blk_add_aio_context_notifier(BlockBackend *blk, + void (*attached_aio_context)(AioContext *new_context, void *opaque), + void (*detach_aio_context)(void *opaque), void *opaque) +{ + if (blk->bs) { + bdrv_add_aio_context_notifier(blk->bs, attached_aio_context, + detach_aio_context, opaque); + } +} + +void blk_remove_aio_context_notifier(BlockBackend *blk, + void (*attached_aio_context)(AioContext *, + void *), + void (*detach_aio_context)(void *), + void *opaque) +{ + if (blk->bs) { + bdrv_remove_aio_context_notifier(blk->bs, attached_aio_context, + detach_aio_context, opaque); + } +} + +void blk_add_close_notifier(BlockBackend *blk, Notifier *notify) +{ + if (blk->bs) { + bdrv_add_close_notifier(blk->bs, notify); + } +} + +void blk_io_plug(BlockBackend *blk) +{ + if (blk->bs) { + bdrv_io_plug(blk->bs); + } +} + +void blk_io_unplug(BlockBackend *blk) +{ + if (blk->bs) { + bdrv_io_unplug(blk->bs); + } +} + +BlockAcctStats *blk_get_stats(BlockBackend *blk) +{ + return &blk->stats; +} + +void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk, + BlockCompletionFunc *cb, void *opaque) +{ + return qemu_aio_get(aiocb_info, blk_bs(blk), cb, opaque); +} + +int coroutine_fn blk_co_write_zeroes(BlockBackend *blk, int64_t sector_num, + int nb_sectors, BdrvRequestFlags flags) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return ret; + } + + return bdrv_co_write_zeroes(blk->bs, sector_num, nb_sectors, flags); +} + +int blk_write_compressed(BlockBackend *blk, int64_t sector_num, + const uint8_t *buf, int nb_sectors) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return ret; + } + + return bdrv_write_compressed(blk->bs, sector_num, buf, nb_sectors); +} + +int blk_truncate(BlockBackend *blk, int64_t offset) +{ + if (!blk_is_available(blk)) { + return -ENOMEDIUM; + } + + return bdrv_truncate(blk->bs, offset); +} + +int blk_discard(BlockBackend *blk, int64_t sector_num, int nb_sectors) +{ + int ret = blk_check_request(blk, sector_num, nb_sectors); + if (ret < 0) { + return ret; + } + + return bdrv_discard(blk->bs, sector_num, nb_sectors); +} + +int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf, + int64_t pos, int size) +{ + if (!blk_is_available(blk)) { + return -ENOMEDIUM; + } + + return bdrv_save_vmstate(blk->bs, buf, pos, size); +} + +int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size) +{ + if (!blk_is_available(blk)) { + return -ENOMEDIUM; + } + + return bdrv_load_vmstate(blk->bs, buf, pos, size); +} + +int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz) +{ + if (!blk_is_available(blk)) { + return -ENOMEDIUM; + } + + return bdrv_probe_blocksizes(blk->bs, bsz); +} + +int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo) +{ + if (!blk_is_available(blk)) { + return -ENOMEDIUM; + } + + return bdrv_probe_geometry(blk->bs, geo); +} + +/* + * Updates the BlockBackendRootState object with data from the currently + * attached BlockDriverState. + */ +void blk_update_root_state(BlockBackend *blk) +{ + assert(blk->bs); + + blk->root_state.open_flags = blk->bs->open_flags; + blk->root_state.read_only = blk->bs->read_only; + blk->root_state.detect_zeroes = blk->bs->detect_zeroes; + + if (blk->root_state.throttle_group) { + g_free(blk->root_state.throttle_group); + throttle_group_unref(blk->root_state.throttle_state); + } + if (blk->bs->throttle_state) { + const char *name = throttle_group_get_name(blk->bs); + blk->root_state.throttle_group = g_strdup(name); + blk->root_state.throttle_state = throttle_group_incref(name); + } else { + blk->root_state.throttle_group = NULL; + blk->root_state.throttle_state = NULL; + } +} + +/* + * Applies the information in the root state to the given BlockDriverState. This + * does not include the flags which have to be specified for bdrv_open(), use + * blk_get_open_flags_from_root_state() to inquire them. + */ +void blk_apply_root_state(BlockBackend *blk, BlockDriverState *bs) +{ + bs->detect_zeroes = blk->root_state.detect_zeroes; + if (blk->root_state.throttle_group) { + bdrv_io_limits_enable(bs, blk->root_state.throttle_group); + } +} + +/* + * Returns the flags to be used for bdrv_open() of a BlockDriverState which is + * supposed to inherit the root state. + */ +int blk_get_open_flags_from_root_state(BlockBackend *blk) +{ + int bs_flags; + + bs_flags = blk->root_state.read_only ? 0 : BDRV_O_RDWR; + bs_flags |= blk->root_state.open_flags & ~BDRV_O_RDWR; + + return bs_flags; +} + +BlockBackendRootState *blk_get_root_state(BlockBackend *blk) +{ + return &blk->root_state; +} |
