X-Git-Url: https://repo.jachan.dev/qemu.git/blobdiff_plain/74d1b8fc27a3dab5743b1fc5ea567640e2acf69b..02c79d78853f07d519b3272d06e43041eb4a4105:/block/block-backend.c diff --git a/block/block-backend.c b/block/block-backend.c index 7a04e10a01..a862f6577b 100644 --- a/block/block-backend.c +++ b/block/block-backend.c @@ -1,7 +1,7 @@ /* * QEMU Block backends * - * Copyright (C) 2014 Red Hat, Inc. + * Copyright (C) 2014-2016 Red Hat, Inc. * * Authors: * Markus Armbruster , @@ -18,18 +18,24 @@ #include "sysemu/blockdev.h" #include "sysemu/sysemu.h" #include "qapi-event.h" +#include "qemu/id.h" +#include "trace.h" /* Number of coroutines to reserve per attached device model */ #define COROUTINE_POOL_RESERVATION 64 +#define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */ + static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb); struct BlockBackend { char *name; int refcnt; - BlockDriverState *bs; + BdrvChild *root; DriveInfo *legacy_dinfo; /* null unless created by drive_new() */ - QTAILQ_ENTRY(BlockBackend) link; /* for blk_backends */ + QTAILQ_ENTRY(BlockBackend) link; /* for block_backends */ + QTAILQ_ENTRY(BlockBackend) monitor_link; /* for monitor_block_backends */ + BlockBackendPublic public; void *dev; /* attached device model, if any */ /* TODO change to DeviceState when all users are qdevified */ @@ -43,6 +49,8 @@ struct BlockBackend { * can be used to restore those options in the new BDS on insert) */ BlockBackendRootState root_state; + bool enable_write_cache; + /* I/O stats (display with "info blockstats"). */ BlockAcctStats stats; @@ -68,69 +76,70 @@ static const AIOCBInfo block_backend_aiocb_info = { }; static void drive_info_del(DriveInfo *dinfo); +static BlockBackend *bdrv_first_blk(BlockDriverState *bs); -/* All the BlockBackends (except for hidden ones) */ -static QTAILQ_HEAD(, BlockBackend) blk_backends = - QTAILQ_HEAD_INITIALIZER(blk_backends); +/* All BlockBackends */ +static QTAILQ_HEAD(, BlockBackend) block_backends = + QTAILQ_HEAD_INITIALIZER(block_backends); + +/* All BlockBackends referenced by the monitor and which are iterated through by + * blk_next() */ +static QTAILQ_HEAD(, BlockBackend) monitor_block_backends = + QTAILQ_HEAD_INITIALIZER(monitor_block_backends); + +static void blk_root_inherit_options(int *child_flags, QDict *child_options, + int parent_flags, QDict *parent_options) +{ + /* We're not supposed to call this function for root nodes */ + abort(); +} +static void blk_root_drained_begin(BdrvChild *child); +static void blk_root_drained_end(BdrvChild *child); + +static void blk_root_change_media(BdrvChild *child, bool load); +static void blk_root_resize(BdrvChild *child); + +static const char *blk_root_get_name(BdrvChild *child) +{ + return blk_name(child->opaque); +} + +static const BdrvChildRole child_root = { + .inherit_options = blk_root_inherit_options, + + .change_media = blk_root_change_media, + .resize = blk_root_resize, + .get_name = blk_root_get_name, + + .drained_begin = blk_root_drained_begin, + .drained_end = blk_root_drained_end, +}; /* - * 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. + * Create a new BlockBackend with a reference count of one. * 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_new(void) { 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; - notifier_list_init(&blk->remove_bs_notifiers); - notifier_list_init(&blk->insert_bs_notifiers); - QTAILQ_INSERT_TAIL(&blk_backends, blk, link); - return blk; -} + blk_set_enable_write_cache(blk, true); -/* - * 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; + qemu_co_queue_init(&blk->public.throttled_reqs[0]); + qemu_co_queue_init(&blk->public.throttled_reqs[1]); - blk = blk_new(name, errp); - if (!blk) { - return NULL; - } + notifier_list_init(&blk->remove_bs_notifiers); + notifier_list_init(&blk->insert_bs_notifiers); - bs = bdrv_new_root(); - blk->bs = bs; - bs->blk = blk; + QTAILQ_INSERT_TAIL(&block_backends, blk, link); return blk; } /* - * Calls blk_new_with_bs() and then calls bdrv_open() on the BlockDriverState. + * Creates a new BlockBackend, opens a new BlockDriverState, and connects both. * * Just as with bdrv_open(), after having called this function the reference to * @options belongs to the block layer (even on failure). @@ -141,46 +150,35 @@ BlockBackend *blk_new_with_bs(const char *name, Error **errp) * 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_new_open(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; - } + BlockDriverState *bs; - ret = bdrv_open(&blk->bs, filename, reference, options, flags, errp); - if (ret < 0) { + blk = blk_new(); + bs = bdrv_open(filename, reference, options, flags, errp); + if (!bs) { blk_unref(blk); return NULL; } + blk->root = bdrv_root_attach_child(bs, "root", &child_root, blk); + return blk; } static void blk_delete(BlockBackend *blk) { assert(!blk->refcnt); + assert(!blk->name); assert(!blk->dev); - if (blk->bs) { + if (blk->root) { blk_remove_bs(blk); } assert(QLIST_EMPTY(&blk->remove_bs_notifiers.notifiers)); assert(QLIST_EMPTY(&blk->insert_bs_notifiers.notifiers)); - 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); + QTAILQ_REMOVE(&block_backends, blk, link); drive_info_del(blk->legacy_dinfo); block_acct_cleanup(&blk->stats); g_free(blk); @@ -225,15 +223,25 @@ void blk_unref(BlockBackend *blk) } } +/* + * Behaves similarly to blk_next() but iterates over all BlockBackends, even the + * ones which are hidden (i.e. are not referenced by the monitor). + */ +static BlockBackend *blk_all_next(BlockBackend *blk) +{ + return blk ? QTAILQ_NEXT(blk, link) + : QTAILQ_FIRST(&block_backends); +} + void blk_remove_all_bs(void) { BlockBackend *blk = NULL; - while ((blk = blk_next(blk)) != NULL) { + while ((blk = blk_all_next(blk)) != NULL) { AioContext *ctx = blk_get_aio_context(blk); aio_context_acquire(ctx); - if (blk->bs) { + if (blk->root) { blk_remove_bs(blk); } aio_context_release(ctx); @@ -241,7 +249,7 @@ void blk_remove_all_bs(void) } /* - * Return the BlockBackend after @blk. + * Return the monitor-owned BlockBackend after @blk. * If @blk is null, return the first one. * Else, return @blk's next sibling, which may be null. * @@ -252,17 +260,108 @@ void blk_remove_all_bs(void) */ BlockBackend *blk_next(BlockBackend *blk) { - return blk ? QTAILQ_NEXT(blk, link) : QTAILQ_FIRST(&blk_backends); + return blk ? QTAILQ_NEXT(blk, monitor_link) + : QTAILQ_FIRST(&monitor_block_backends); +} + +/* Iterates over all top-level BlockDriverStates, i.e. BDSs that are owned by + * the monitor or attached to a BlockBackend */ +BlockDriverState *bdrv_next(BdrvNextIterator *it) +{ + BlockDriverState *bs; + + /* First, return all root nodes of BlockBackends. In order to avoid + * returning a BDS twice when multiple BBs refer to it, we only return it + * if the BB is the first one in the parent list of the BDS. */ + if (it->phase == BDRV_NEXT_BACKEND_ROOTS) { + do { + it->blk = blk_all_next(it->blk); + bs = it->blk ? blk_bs(it->blk) : NULL; + } while (it->blk && (bs == NULL || bdrv_first_blk(bs) != it->blk)); + + if (bs) { + return bs; + } + it->phase = BDRV_NEXT_MONITOR_OWNED; + } + + /* Then return the monitor-owned BDSes without a BB attached. Ignore all + * BDSes that are attached to a BlockBackend here; they have been handled + * by the above block already */ + do { + it->bs = bdrv_next_monitor_owned(it->bs); + bs = it->bs; + } while (bs && bdrv_has_blk(bs)); + + return bs; +} + +BlockDriverState *bdrv_first(BdrvNextIterator *it) +{ + *it = (BdrvNextIterator) { + .phase = BDRV_NEXT_BACKEND_ROOTS, + }; + + return bdrv_next(it); +} + +/* + * Add a BlockBackend into the list of backends referenced by the monitor, with + * the given @name acting as the handle for the monitor. + * Strictly for use by blockdev.c. + * + * @name must not be null or empty. + * + * Returns true on success and false on failure. In the latter case, an Error + * object is returned through @errp. + */ +bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp) +{ + assert(!blk->name); + assert(name && name[0]); + + if (!id_wellformed(name)) { + error_setg(errp, "Invalid device name"); + return false; + } + if (blk_by_name(name)) { + error_setg(errp, "Device with id '%s' already exists", name); + return false; + } + if (bdrv_find_node(name)) { + error_setg(errp, + "Device name '%s' conflicts with an existing node name", + name); + return false; + } + + blk->name = g_strdup(name); + QTAILQ_INSERT_TAIL(&monitor_block_backends, blk, monitor_link); + return true; +} + +/* + * Remove a BlockBackend from the list of backends referenced by the monitor. + * Strictly for use by blockdev.c. + */ +void monitor_remove_blk(BlockBackend *blk) +{ + if (!blk->name) { + return; + } + + QTAILQ_REMOVE(&monitor_block_backends, blk, monitor_link); + g_free(blk->name); + blk->name = NULL; } /* * 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(). + * Returns an empty string iff @blk is not referenced by the monitor. */ const char *blk_name(BlockBackend *blk) { - return blk->name; + return blk->name ?: ""; } /* @@ -287,24 +386,27 @@ BlockBackend *blk_by_name(const char *name) */ BlockDriverState *blk_bs(BlockBackend *blk) { - return blk->bs; + return blk->root ? blk->root->bs : NULL; } -/* - * Changes the BlockDriverState attached to @blk - */ -void blk_set_bs(BlockBackend *blk, BlockDriverState *bs) +static BlockBackend *bdrv_first_blk(BlockDriverState *bs) { - bdrv_ref(bs); - - if (blk->bs) { - blk->bs->blk = NULL; - bdrv_unref(blk->bs); + BdrvChild *child; + QLIST_FOREACH(child, &bs->parents, next_parent) { + if (child->role == &child_root) { + return child->opaque; + } } - assert(bs->blk == NULL); - blk->bs = bs; - bs->blk = blk; + return NULL; +} + +/* + * Returns true if @bs has an associated BlockBackend. + */ +bool bdrv_has_blk(BlockDriverState *bs) +{ + return bdrv_first_blk(bs) != NULL; } /* @@ -343,21 +445,19 @@ BlockBackend *blk_by_legacy_dinfo(DriveInfo *dinfo) } /* - * 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! + * Returns a pointer to the publicly accessible fields of @blk. */ -void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk) +BlockBackendPublic *blk_get_public(BlockBackend *blk) { - QTAILQ_REMOVE(&blk_backends, blk, link); - blk->name[0] = 0; - if (blk->bs) { - bdrv_make_anon(blk->bs); - } + return &blk->public; +} + +/* + * Returns a BlockBackend given the associated @public fields. + */ +BlockBackend *blk_by_public(BlockBackendPublic *public) +{ + return container_of(public, BlockBackend, public); } /* @@ -365,15 +465,15 @@ void blk_hide_on_behalf_of_hmp_drive_del(BlockBackend *blk) */ void blk_remove_bs(BlockBackend *blk) { - assert(blk->bs->blk == blk); - notifier_list_notify(&blk->remove_bs_notifiers, blk); + if (blk->public.throttle_state) { + throttle_timers_detach_aio_context(&blk->public.throttle_timers); + } blk_update_root_state(blk); - blk->bs->blk = NULL; - bdrv_unref(blk->bs); - blk->bs = NULL; + bdrv_root_unref_child(blk->root); + blk->root = NULL; } /* @@ -381,12 +481,14 @@ void blk_remove_bs(BlockBackend *blk) */ void blk_insert_bs(BlockBackend *blk, BlockDriverState *bs) { - assert(!blk->bs && !bs->blk); bdrv_ref(bs); - blk->bs = bs; - bs->blk = blk; + blk->root = bdrv_root_attach_child(bs, "root", &child_root, blk); notifier_list_notify(&blk->insert_bs_notifiers, blk); + if (blk->public.throttle_state) { + throttle_timers_attach_aio_context( + &blk->public.throttle_timers, bdrv_get_aio_context(bs)); + } } /* @@ -475,6 +577,11 @@ void blk_dev_change_media_cb(BlockBackend *blk, bool load) } } +static void blk_root_change_media(BdrvChild *child, bool load) +{ + blk_dev_change_media_cb(child->opaque, load); +} + /* * Does @blk's attached device model have removable media? * %true if no device model is attached. @@ -529,8 +636,10 @@ bool blk_dev_is_medium_locked(BlockBackend *blk) /* * Notify @blk's attached device model of a backend size change. */ -void blk_dev_resize_cb(BlockBackend *blk) +static void blk_root_resize(BdrvChild *child) { + BlockBackend *blk = child->opaque; + if (blk->dev_ops && blk->dev_ops->resize_cb) { blk->dev_ops->resize_cb(blk->dev_opaque); } @@ -565,9 +674,10 @@ void blk_iostatus_disable(BlockBackend *blk) void blk_iostatus_reset(BlockBackend *blk) { if (blk_iostatus_is_enabled(blk)) { + BlockDriverState *bs = blk_bs(blk); blk->iostatus = BLOCK_DEVICE_IO_STATUS_OK; - if (blk->bs && blk->bs->job) { - block_job_iostatus_reset(blk->bs->job); + if (bs && bs->job) { + block_job_iostatus_reset(bs->job); } } } @@ -632,48 +742,137 @@ static int blk_check_request(BlockBackend *blk, int64_t sector_num, nb_sectors * BDRV_SECTOR_SIZE); } -int blk_read(BlockBackend *blk, int64_t sector_num, uint8_t *buf, - int nb_sectors) +int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset, + unsigned int bytes, QEMUIOVector *qiov, + BdrvRequestFlags flags) { - int ret = blk_check_request(blk, sector_num, nb_sectors); + int ret; + + trace_blk_co_preadv(blk, blk_bs(blk), offset, bytes, flags); + + ret = blk_check_byte_request(blk, offset, bytes); if (ret < 0) { return ret; } - return bdrv_read(blk->bs, sector_num, buf, nb_sectors); + /* throttling disk I/O */ + if (blk->public.throttle_state) { + throttle_group_co_io_limits_intercept(blk, bytes, false); + } + + return bdrv_co_preadv(blk->root, offset, bytes, qiov, flags); } -int blk_read_unthrottled(BlockBackend *blk, int64_t sector_num, uint8_t *buf, - int nb_sectors) +int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset, + unsigned int bytes, QEMUIOVector *qiov, + BdrvRequestFlags flags) { - int ret = blk_check_request(blk, sector_num, nb_sectors); + int ret; + + trace_blk_co_pwritev(blk, blk_bs(blk), offset, bytes, flags); + + ret = blk_check_byte_request(blk, offset, bytes); if (ret < 0) { return ret; } - return bdrv_read_unthrottled(blk->bs, sector_num, buf, nb_sectors); + /* throttling disk I/O */ + if (blk->public.throttle_state) { + throttle_group_co_io_limits_intercept(blk, bytes, true); + } + + if (!blk->enable_write_cache) { + flags |= BDRV_REQ_FUA; + } + + return bdrv_co_pwritev(blk->root, offset, bytes, qiov, flags); +} + +typedef struct BlkRwCo { + BlockBackend *blk; + int64_t offset; + QEMUIOVector *qiov; + int ret; + BdrvRequestFlags flags; +} BlkRwCo; + +static void blk_read_entry(void *opaque) +{ + BlkRwCo *rwco = opaque; + + rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, rwco->qiov->size, + rwco->qiov, rwco->flags); } -int blk_write(BlockBackend *blk, int64_t sector_num, const uint8_t *buf, - int nb_sectors) +static void blk_write_entry(void *opaque) { - int ret = blk_check_request(blk, sector_num, nb_sectors); - if (ret < 0) { - return ret; + BlkRwCo *rwco = opaque; + + rwco->ret = blk_co_pwritev(rwco->blk, rwco->offset, rwco->qiov->size, + rwco->qiov, rwco->flags); +} + +static int blk_prw(BlockBackend *blk, int64_t offset, uint8_t *buf, + int64_t bytes, CoroutineEntry co_entry, + BdrvRequestFlags flags) +{ + AioContext *aio_context; + QEMUIOVector qiov; + struct iovec iov; + Coroutine *co; + BlkRwCo rwco; + + iov = (struct iovec) { + .iov_base = buf, + .iov_len = bytes, + }; + qemu_iovec_init_external(&qiov, &iov, 1); + + rwco = (BlkRwCo) { + .blk = blk, + .offset = offset, + .qiov = &qiov, + .flags = flags, + .ret = NOT_DONE, + }; + + co = qemu_coroutine_create(co_entry); + qemu_coroutine_enter(co, &rwco); + + aio_context = blk_get_aio_context(blk); + while (rwco.ret == NOT_DONE) { + aio_poll(aio_context, true); } - return bdrv_write(blk->bs, sector_num, buf, nb_sectors); + return rwco.ret; } -int blk_write_zeroes(BlockBackend *blk, int64_t sector_num, - int nb_sectors, BdrvRequestFlags flags) +int blk_pread_unthrottled(BlockBackend *blk, int64_t offset, uint8_t *buf, + int count) { - int ret = blk_check_request(blk, sector_num, nb_sectors); + int ret; + + ret = blk_check_byte_request(blk, offset, count); if (ret < 0) { return ret; } - return bdrv_write_zeroes(blk->bs, sector_num, nb_sectors, flags); + blk_root_drained_begin(blk->root); + ret = blk_pread(blk, offset, buf, count); + blk_root_drained_end(blk->root); + return ret; +} + +int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset, + int count, BdrvRequestFlags flags) +{ + return blk_prw(blk, offset, NULL, count, blk_write_entry, + flags | BDRV_REQ_ZERO_WRITE); +} + +int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags) +{ + return bdrv_make_zero(blk->root, flags); } static void error_callback_bh(void *opaque) @@ -702,37 +901,115 @@ BlockAIOCB *blk_abort_aio_request(BlockBackend *blk, return &acb->common; } -BlockAIOCB *blk_aio_write_zeroes(BlockBackend *blk, int64_t sector_num, - int nb_sectors, BdrvRequestFlags flags, - BlockCompletionFunc *cb, void *opaque) +typedef struct BlkAioEmAIOCB { + BlockAIOCB common; + BlkRwCo rwco; + int bytes; + bool has_returned; + QEMUBH* bh; +} BlkAioEmAIOCB; + +static const AIOCBInfo blk_aio_em_aiocb_info = { + .aiocb_size = sizeof(BlkAioEmAIOCB), +}; + +static void blk_aio_complete(BlkAioEmAIOCB *acb) { - int ret = blk_check_request(blk, sector_num, nb_sectors); - if (ret < 0) { - return blk_abort_aio_request(blk, cb, opaque, ret); + if (acb->bh) { + assert(acb->has_returned); + qemu_bh_delete(acb->bh); + } + if (acb->has_returned) { + acb->common.cb(acb->common.opaque, acb->rwco.ret); + qemu_aio_unref(acb); + } +} + +static void blk_aio_complete_bh(void *opaque) +{ + blk_aio_complete(opaque); +} + +static BlockAIOCB *blk_aio_prwv(BlockBackend *blk, int64_t offset, int bytes, + QEMUIOVector *qiov, CoroutineEntry co_entry, + BdrvRequestFlags flags, + BlockCompletionFunc *cb, void *opaque) +{ + BlkAioEmAIOCB *acb; + Coroutine *co; + + acb = blk_aio_get(&blk_aio_em_aiocb_info, blk, cb, opaque); + acb->rwco = (BlkRwCo) { + .blk = blk, + .offset = offset, + .qiov = qiov, + .flags = flags, + .ret = NOT_DONE, + }; + acb->bytes = bytes; + acb->bh = NULL; + acb->has_returned = false; + + co = qemu_coroutine_create(co_entry); + qemu_coroutine_enter(co, acb); + + acb->has_returned = true; + if (acb->rwco.ret != NOT_DONE) { + acb->bh = aio_bh_new(blk_get_aio_context(blk), blk_aio_complete_bh, acb); + qemu_bh_schedule(acb->bh); } - return bdrv_aio_write_zeroes(blk->bs, sector_num, nb_sectors, flags, - cb, opaque); + return &acb->common; +} + +static void blk_aio_read_entry(void *opaque) +{ + BlkAioEmAIOCB *acb = opaque; + BlkRwCo *rwco = &acb->rwco; + + assert(rwco->qiov->size == acb->bytes); + rwco->ret = blk_co_preadv(rwco->blk, rwco->offset, acb->bytes, + rwco->qiov, rwco->flags); + blk_aio_complete(acb); +} + +static void blk_aio_write_entry(void *opaque) +{ + BlkAioEmAIOCB *acb = opaque; + BlkRwCo *rwco = &acb->rwco; + + assert(!rwco->qiov || rwco->qiov->size == acb->bytes); + rwco->ret = blk_co_pwritev(rwco->blk, rwco->offset, acb->bytes, + rwco->qiov, rwco->flags); + blk_aio_complete(acb); +} + +BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset, + int count, BdrvRequestFlags flags, + BlockCompletionFunc *cb, void *opaque) +{ + return blk_aio_prwv(blk, offset, count, NULL, blk_aio_write_entry, + flags | BDRV_REQ_ZERO_WRITE, cb, opaque); } int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int count) { - int ret = blk_check_byte_request(blk, offset, count); + int ret = blk_prw(blk, offset, buf, count, blk_read_entry, 0); if (ret < 0) { return ret; } - - return bdrv_pread(blk->bs, offset, buf, count); + return count; } -int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int count) +int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int count, + BdrvRequestFlags flags) { - int ret = blk_check_byte_request(blk, offset, count); + int ret = blk_prw(blk, offset, (void *) buf, count, blk_write_entry, + flags); if (ret < 0) { return ret; } - - return bdrv_pwrite(blk->bs, offset, buf, count); + return count; } int64_t blk_getlength(BlockBackend *blk) @@ -741,15 +1018,15 @@ int64_t blk_getlength(BlockBackend *blk) return -ENOMEDIUM; } - return bdrv_getlength(blk->bs); + return bdrv_getlength(blk_bs(blk)); } void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr) { - if (!blk->bs) { + if (!blk_bs(blk)) { *nb_sectors_ptr = 0; } else { - bdrv_get_geometry(blk->bs, nb_sectors_ptr); + bdrv_get_geometry(blk_bs(blk), nb_sectors_ptr); } } @@ -759,31 +1036,23 @@ int64_t blk_nb_sectors(BlockBackend *blk) return -ENOMEDIUM; } - return bdrv_nb_sectors(blk->bs); + return bdrv_nb_sectors(blk_bs(blk)); } -BlockAIOCB *blk_aio_readv(BlockBackend *blk, int64_t sector_num, - QEMUIOVector *iov, int nb_sectors, - BlockCompletionFunc *cb, void *opaque) +BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset, + QEMUIOVector *qiov, 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_readv(blk->bs, sector_num, iov, nb_sectors, cb, opaque); + return blk_aio_prwv(blk, offset, qiov->size, qiov, + blk_aio_read_entry, flags, cb, opaque); } -BlockAIOCB *blk_aio_writev(BlockBackend *blk, int64_t sector_num, - QEMUIOVector *iov, int nb_sectors, - BlockCompletionFunc *cb, void *opaque) +BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset, + QEMUIOVector *qiov, 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_writev(blk->bs, sector_num, iov, nb_sectors, cb, opaque); + return blk_aio_prwv(blk, offset, qiov->size, qiov, + blk_aio_write_entry, flags, cb, opaque); } BlockAIOCB *blk_aio_flush(BlockBackend *blk, @@ -793,7 +1062,7 @@ BlockAIOCB *blk_aio_flush(BlockBackend *blk, return blk_abort_aio_request(blk, cb, opaque, -ENOMEDIUM); } - return bdrv_aio_flush(blk->bs, cb, opaque); + return bdrv_aio_flush(blk_bs(blk), cb, opaque); } BlockAIOCB *blk_aio_discard(BlockBackend *blk, @@ -805,7 +1074,7 @@ BlockAIOCB *blk_aio_discard(BlockBackend *blk, return blk_abort_aio_request(blk, cb, opaque, ret); } - return bdrv_aio_discard(blk->bs, sector_num, nb_sectors, cb, opaque); + return bdrv_aio_discard(blk_bs(blk), sector_num, nb_sectors, cb, opaque); } void blk_aio_cancel(BlockAIOCB *acb) @@ -818,27 +1087,13 @@ 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); + return bdrv_ioctl(blk_bs(blk), req, buf); } BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf, @@ -848,7 +1103,7 @@ BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf, return blk_abort_aio_request(blk, cb, opaque, -ENOMEDIUM); } - return bdrv_aio_ioctl(blk->bs, req, buf, cb, opaque); + return bdrv_aio_ioctl(blk_bs(blk), req, buf, cb, opaque); } int blk_co_discard(BlockBackend *blk, int64_t sector_num, int nb_sectors) @@ -858,7 +1113,7 @@ int blk_co_discard(BlockBackend *blk, int64_t sector_num, int nb_sectors) return ret; } - return bdrv_co_discard(blk->bs, sector_num, nb_sectors); + return bdrv_co_discard(blk_bs(blk), sector_num, nb_sectors); } int blk_co_flush(BlockBackend *blk) @@ -867,7 +1122,7 @@ int blk_co_flush(BlockBackend *blk) return -ENOMEDIUM; } - return bdrv_co_flush(blk->bs); + return bdrv_co_flush(blk_bs(blk)); } int blk_flush(BlockBackend *blk) @@ -876,18 +1131,13 @@ int blk_flush(BlockBackend *blk) return -ENOMEDIUM; } - return bdrv_flush(blk->bs); -} - -int blk_flush_all(void) -{ - return bdrv_flush_all(); + return bdrv_flush(blk_bs(blk)); } void blk_drain(BlockBackend *blk) { - if (blk->bs) { - bdrv_drain(blk->bs); + if (blk_bs(blk)) { + bdrv_drain(blk_bs(blk)); } } @@ -975,8 +1225,10 @@ void blk_error_action(BlockBackend *blk, BlockErrorAction action, int blk_is_read_only(BlockBackend *blk) { - if (blk->bs) { - return bdrv_is_read_only(blk->bs); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + return bdrv_is_read_only(bs); } else { return blk->root_state.read_only; } @@ -984,48 +1236,42 @@ int blk_is_read_only(BlockBackend *blk) int blk_is_sg(BlockBackend *blk) { - if (!blk->bs) { + BlockDriverState *bs = blk_bs(blk); + + if (!bs) { return 0; } - return bdrv_is_sg(blk->bs); + return bdrv_is_sg(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); - } + return blk->enable_write_cache; } 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; - } - } + blk->enable_write_cache = wce; } void blk_invalidate_cache(BlockBackend *blk, Error **errp) { - if (!blk->bs) { + BlockDriverState *bs = blk_bs(blk); + + if (!bs) { error_setg(errp, "Device '%s' has no medium", blk->name); return; } - bdrv_invalidate_cache(blk->bs, errp); + bdrv_invalidate_cache(bs, errp); } bool blk_is_inserted(BlockBackend *blk) { - return blk->bs && bdrv_is_inserted(blk->bs); + BlockDriverState *bs = blk_bs(blk); + + return bs && bdrv_is_inserted(bs); } bool blk_is_available(BlockBackend *blk) @@ -1035,39 +1281,48 @@ bool blk_is_available(BlockBackend *blk) void blk_lock_medium(BlockBackend *blk, bool locked) { - if (blk->bs) { - bdrv_lock_medium(blk->bs, locked); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + bdrv_lock_medium(bs, locked); } } void blk_eject(BlockBackend *blk, bool eject_flag) { - if (blk->bs) { - bdrv_eject(blk->bs, eject_flag); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + bdrv_eject(bs, eject_flag); } } int blk_get_flags(BlockBackend *blk) { - if (blk->bs) { - return bdrv_get_flags(blk->bs); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + return bdrv_get_flags(bs); } else { return blk->root_state.open_flags; } } -int blk_get_max_transfer_length(BlockBackend *blk) +/* Returns the maximum transfer length, in bytes; guaranteed nonzero */ +uint32_t blk_get_max_transfer(BlockBackend *blk) { - if (blk->bs) { - return blk->bs->bl.max_transfer_length; - } else { - return 0; + BlockDriverState *bs = blk_bs(blk); + uint32_t max = 0; + + if (bs) { + max = bs->bl.max_transfer; } + return MIN_NON_ZERO(max, INT_MAX); } int blk_get_max_iov(BlockBackend *blk) { - return blk->bs->bl.max_iov; + return blk->root->bs->bl.max_iov; } void blk_set_guest_block_size(BlockBackend *blk, int align) @@ -1077,48 +1332,58 @@ void blk_set_guest_block_size(BlockBackend *blk, int align) void *blk_try_blockalign(BlockBackend *blk, size_t size) { - return qemu_try_blockalign(blk ? blk->bs : NULL, size); + return qemu_try_blockalign(blk ? blk_bs(blk) : NULL, size); } void *blk_blockalign(BlockBackend *blk, size_t size) { - return qemu_blockalign(blk ? blk->bs : NULL, size); + return qemu_blockalign(blk ? blk_bs(blk) : NULL, size); } bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp) { - if (!blk->bs) { + BlockDriverState *bs = blk_bs(blk); + + if (!bs) { return false; } - return bdrv_op_is_blocked(blk->bs, op, errp); + return bdrv_op_is_blocked(bs, op, errp); } void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason) { - if (blk->bs) { - bdrv_op_unblock(blk->bs, op, reason); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + bdrv_op_unblock(bs, op, reason); } } void blk_op_block_all(BlockBackend *blk, Error *reason) { - if (blk->bs) { - bdrv_op_block_all(blk->bs, reason); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + bdrv_op_block_all(bs, reason); } } void blk_op_unblock_all(BlockBackend *blk, Error *reason) { - if (blk->bs) { - bdrv_op_unblock_all(blk->bs, reason); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + bdrv_op_unblock_all(bs, reason); } } AioContext *blk_get_aio_context(BlockBackend *blk) { - if (blk->bs) { - return bdrv_get_aio_context(blk->bs); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + return bdrv_get_aio_context(bs); } else { return qemu_get_aio_context(); } @@ -1132,8 +1397,17 @@ static AioContext *blk_aiocb_get_aio_context(BlockAIOCB *acb) void blk_set_aio_context(BlockBackend *blk, AioContext *new_context) { - if (blk->bs) { - bdrv_set_aio_context(blk->bs, new_context); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + if (blk->public.throttle_state) { + throttle_timers_detach_aio_context(&blk->public.throttle_timers); + } + bdrv_set_aio_context(bs, new_context); + if (blk->public.throttle_state) { + throttle_timers_attach_aio_context(&blk->public.throttle_timers, + new_context); + } } } @@ -1141,8 +1415,10 @@ 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, + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + bdrv_add_aio_context_notifier(bs, attached_aio_context, detach_aio_context, opaque); } } @@ -1153,8 +1429,10 @@ void blk_remove_aio_context_notifier(BlockBackend *blk, void (*detach_aio_context)(void *), void *opaque) { - if (blk->bs) { - bdrv_remove_aio_context_notifier(blk->bs, attached_aio_context, + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + bdrv_remove_aio_context_notifier(bs, attached_aio_context, detach_aio_context, opaque); } } @@ -1171,15 +1449,19 @@ void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify) void blk_io_plug(BlockBackend *blk) { - if (blk->bs) { - bdrv_io_plug(blk->bs); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + bdrv_io_plug(bs); } } void blk_io_unplug(BlockBackend *blk) { - if (blk->bs) { - bdrv_io_unplug(blk->bs); + BlockDriverState *bs = blk_bs(blk); + + if (bs) { + bdrv_io_unplug(bs); } } @@ -1194,15 +1476,11 @@ void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk, 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 coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset, + int count, 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); + return blk_co_pwritev(blk, offset, count, NULL, + flags | BDRV_REQ_ZERO_WRITE); } int blk_write_compressed(BlockBackend *blk, int64_t sector_num, @@ -1213,7 +1491,7 @@ int blk_write_compressed(BlockBackend *blk, int64_t sector_num, return ret; } - return bdrv_write_compressed(blk->bs, sector_num, buf, nb_sectors); + return bdrv_write_compressed(blk_bs(blk), sector_num, buf, nb_sectors); } int blk_truncate(BlockBackend *blk, int64_t offset) @@ -1222,7 +1500,7 @@ int blk_truncate(BlockBackend *blk, int64_t offset) return -ENOMEDIUM; } - return bdrv_truncate(blk->bs, offset); + return bdrv_truncate(blk_bs(blk), offset); } int blk_discard(BlockBackend *blk, int64_t sector_num, int nb_sectors) @@ -1232,17 +1510,28 @@ int blk_discard(BlockBackend *blk, int64_t sector_num, int nb_sectors) return ret; } - return bdrv_discard(blk->bs, sector_num, nb_sectors); + return bdrv_discard(blk_bs(blk), sector_num, nb_sectors); } int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf, int64_t pos, int size) { + int ret; + if (!blk_is_available(blk)) { return -ENOMEDIUM; } - return bdrv_save_vmstate(blk->bs, buf, pos, size); + ret = bdrv_save_vmstate(blk_bs(blk), buf, pos, size); + if (ret < 0) { + return ret; + } + + if (ret == size && !blk->enable_write_cache) { + ret = bdrv_flush(blk_bs(blk)); + } + + return ret < 0 ? ret : size; } int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size) @@ -1251,7 +1540,7 @@ int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size) return -ENOMEDIUM; } - return bdrv_load_vmstate(blk->bs, buf, pos, size); + return bdrv_load_vmstate(blk_bs(blk), buf, pos, size); } int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz) @@ -1260,7 +1549,7 @@ int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz) return -ENOMEDIUM; } - return bdrv_probe_blocksizes(blk->bs, bsz); + return bdrv_probe_blocksizes(blk_bs(blk), bsz); } int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo) @@ -1269,7 +1558,7 @@ int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo) return -ENOMEDIUM; } - return bdrv_probe_geometry(blk->bs, geo); + return bdrv_probe_geometry(blk_bs(blk), geo); } /* @@ -1278,24 +1567,11 @@ int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo) */ 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; + assert(blk->root); - 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; - } + blk->root_state.open_flags = blk->root->bs->open_flags; + blk->root_state.read_only = blk->root->bs->read_only; + blk->root_state.detect_zeroes = blk->root->bs->detect_zeroes; } /* @@ -1306,9 +1582,6 @@ void blk_update_root_state(BlockBackend *blk) 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); - } } /* @@ -1329,3 +1602,104 @@ BlockBackendRootState *blk_get_root_state(BlockBackend *blk) { return &blk->root_state; } + +int blk_commit_all(void) +{ + BlockBackend *blk = NULL; + + while ((blk = blk_all_next(blk)) != NULL) { + AioContext *aio_context = blk_get_aio_context(blk); + + aio_context_acquire(aio_context); + if (blk_is_inserted(blk) && blk->root->bs->backing) { + int ret = bdrv_commit(blk->root->bs); + if (ret < 0) { + aio_context_release(aio_context); + return ret; + } + } + aio_context_release(aio_context); + } + return 0; +} + +int blk_flush_all(void) +{ + BlockBackend *blk = NULL; + int result = 0; + + while ((blk = blk_all_next(blk)) != NULL) { + AioContext *aio_context = blk_get_aio_context(blk); + int ret; + + aio_context_acquire(aio_context); + if (blk_is_inserted(blk)) { + ret = blk_flush(blk); + if (ret < 0 && !result) { + result = ret; + } + } + aio_context_release(aio_context); + } + + return result; +} + + +/* throttling disk I/O limits */ +void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg) +{ + throttle_group_config(blk, cfg); +} + +void blk_io_limits_disable(BlockBackend *blk) +{ + assert(blk->public.throttle_state); + bdrv_drained_begin(blk_bs(blk)); + throttle_group_unregister_blk(blk); + bdrv_drained_end(blk_bs(blk)); +} + +/* should be called before blk_set_io_limits if a limit is set */ +void blk_io_limits_enable(BlockBackend *blk, const char *group) +{ + assert(!blk->public.throttle_state); + throttle_group_register_blk(blk, group); +} + +void blk_io_limits_update_group(BlockBackend *blk, const char *group) +{ + /* this BB is not part of any group */ + if (!blk->public.throttle_state) { + return; + } + + /* this BB is a part of the same group than the one we want */ + if (!g_strcmp0(throttle_group_get_name(blk), group)) { + return; + } + + /* need to change the group this bs belong to */ + blk_io_limits_disable(blk); + blk_io_limits_enable(blk, group); +} + +static void blk_root_drained_begin(BdrvChild *child) +{ + BlockBackend *blk = child->opaque; + + /* Note that blk->root may not be accessible here yet if we are just + * attaching to a BlockDriverState that is drained. Use child instead. */ + + if (blk->public.io_limits_disabled++ == 0) { + throttle_group_restart_blk(blk); + } +} + +static void blk_root_drained_end(BdrvChild *child) +{ + BlockBackend *blk = child->opaque; + + assert(blk->public.io_limits_disabled); + --blk->public.io_limits_disabled; +}