/* * 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 "sysemu/blockdev.h" #include "qapi-event.h" /* Number of coroutines to reserve per attached device model */ #define COROUTINE_POOL_RESERVATION 64 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; }; typedef struct BlockBackendAIOCB { BlockAIOCB common; QEMUBH *bh; int ret; } BlockBackendAIOCB; static const AIOCBInfo block_backend_aiocb_info = { .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, NULL, 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; } /* 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); 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); } /* * 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; } /* * 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); } } /* * 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; bdrv_iostatus_reset(blk->bs); 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; bdrv_set_guest_block_size(blk->bs, 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_closed = !blk_dev_is_tray_open(blk); blk->dev_ops->change_media_cb(blk->dev_opaque, load); if (tray_was_closed) { /* tray open */ qapi_event_send_device_tray_moved(blk_name(blk), true, &error_abort); } if (load) { /* tray close */ qapi_event_send_device_tray_moved(blk_name(blk), false, &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); } /* * 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_ops && blk->dev_ops->is_tray_open) { 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) { bdrv_iostatus_enable(blk->bs); } 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_inserted(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); } static BlockAIOCB *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->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 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) { return bdrv_getlength(blk->bs); } void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr) { bdrv_get_geometry(blk->bs, nb_sectors_ptr); } int64_t blk_nb_sectors(BlockBackend *blk) { 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 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 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) { 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 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) { return bdrv_ioctl(blk->bs, req, buf); } BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf, BlockCompletionFunc *cb, void *opaque) { 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) { return bdrv_co_flush(blk->bs); } int blk_flush(BlockBackend *blk) { return bdrv_flush(blk->bs); } int blk_flush_all(void) { return bdrv_flush_all(); } void blk_drain_all(void) { bdrv_drain_all(); } BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read) { return bdrv_get_on_error(blk->bs, is_read); } BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read, int error) { return bdrv_get_error_action(blk->bs, is_read, error); } void blk_error_action(BlockBackend *blk, BlockErrorAction action, bool is_read, int error) { bdrv_error_action(blk->bs, action, is_read, error); } int blk_is_read_only(BlockBackend *blk) { return bdrv_is_read_only(blk->bs); } int blk_is_sg(BlockBackend *blk) { return bdrv_is_sg(blk->bs); } int blk_enable_write_cache(BlockBackend *blk) { return bdrv_enable_write_cache(blk->bs); } void blk_set_enable_write_cache(BlockBackend *blk, bool wce) { bdrv_set_enable_write_cache(blk->bs, wce); } void blk_invalidate_cache(BlockBackend *blk, Error **errp) { bdrv_invalidate_cache(blk->bs, errp); } int blk_is_inserted(BlockBackend *blk) { return bdrv_is_inserted(blk->bs); } void blk_lock_medium(BlockBackend *blk, bool locked) { bdrv_lock_medium(blk->bs, locked); } void blk_eject(BlockBackend *blk, bool eject_flag) { bdrv_eject(blk->bs, eject_flag); } int blk_get_flags(BlockBackend *blk) { return bdrv_get_flags(blk->bs); } int blk_get_max_transfer_length(BlockBackend *blk) { return blk->bs->bl.max_transfer_length; } void blk_set_guest_block_size(BlockBackend *blk, int align) { bdrv_set_guest_block_size(blk->bs, 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) { return bdrv_op_is_blocked(blk->bs, op, errp); } void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason) { bdrv_op_unblock(blk->bs, op, reason); } void blk_op_block_all(BlockBackend *blk, Error *reason) { bdrv_op_block_all(blk->bs, reason); } void blk_op_unblock_all(BlockBackend *blk, Error *reason) { bdrv_op_unblock_all(blk->bs, reason); } AioContext *blk_get_aio_context(BlockBackend *blk) { return bdrv_get_aio_context(blk->bs); } void blk_set_aio_context(BlockBackend *blk, AioContext *new_context) { 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) { 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) { bdrv_remove_aio_context_notifier(blk->bs, attached_aio_context, detach_aio_context, opaque); } void blk_add_close_notifier(BlockBackend *blk, Notifier *notify) { bdrv_add_close_notifier(blk->bs, notify); } void blk_io_plug(BlockBackend *blk) { bdrv_io_plug(blk->bs); } void blk_io_unplug(BlockBackend *blk) { bdrv_io_unplug(blk->bs); } BlockAcctStats *blk_get_stats(BlockBackend *blk) { return bdrv_get_stats(blk->bs); } 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) { 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) { return bdrv_save_vmstate(blk->bs, buf, pos, size); } int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size) { return bdrv_load_vmstate(blk->bs, buf, pos, size); } int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz) { return bdrv_probe_blocksizes(blk->bs, bsz); } int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo) { return bdrv_probe_geometry(blk->bs, geo); }