xref: /qemu/block/io.c (revision d05aa8bb4a8b6aa9a915ec5074fb12ae632d2323)
161007b31SStefan Hajnoczi /*
261007b31SStefan Hajnoczi  * Block layer I/O functions
361007b31SStefan Hajnoczi  *
461007b31SStefan Hajnoczi  * Copyright (c) 2003 Fabrice Bellard
561007b31SStefan Hajnoczi  *
661007b31SStefan Hajnoczi  * Permission is hereby granted, free of charge, to any person obtaining a copy
761007b31SStefan Hajnoczi  * of this software and associated documentation files (the "Software"), to deal
861007b31SStefan Hajnoczi  * in the Software without restriction, including without limitation the rights
961007b31SStefan Hajnoczi  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
1061007b31SStefan Hajnoczi  * copies of the Software, and to permit persons to whom the Software is
1161007b31SStefan Hajnoczi  * furnished to do so, subject to the following conditions:
1261007b31SStefan Hajnoczi  *
1361007b31SStefan Hajnoczi  * The above copyright notice and this permission notice shall be included in
1461007b31SStefan Hajnoczi  * all copies or substantial portions of the Software.
1561007b31SStefan Hajnoczi  *
1661007b31SStefan Hajnoczi  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
1761007b31SStefan Hajnoczi  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
1861007b31SStefan Hajnoczi  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
1961007b31SStefan Hajnoczi  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
2061007b31SStefan Hajnoczi  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
2161007b31SStefan Hajnoczi  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
2261007b31SStefan Hajnoczi  * THE SOFTWARE.
2361007b31SStefan Hajnoczi  */
2461007b31SStefan Hajnoczi 
2580c71a24SPeter Maydell #include "qemu/osdep.h"
2661007b31SStefan Hajnoczi #include "trace.h"
277f0e9da6SMax Reitz #include "sysemu/block-backend.h"
2861007b31SStefan Hajnoczi #include "block/blockjob.h"
2961007b31SStefan Hajnoczi #include "block/block_int.h"
30f348b6d1SVeronia Bahaa #include "qemu/cutils.h"
31da34e65cSMarkus Armbruster #include "qapi/error.h"
32d49b6836SMarkus Armbruster #include "qemu/error-report.h"
3361007b31SStefan Hajnoczi 
3461007b31SStefan Hajnoczi #define NOT_DONE 0x7fffffff /* used while emulated sync operation in progress */
3561007b31SStefan Hajnoczi 
3661007b31SStefan Hajnoczi static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
3761007b31SStefan Hajnoczi                                          int64_t sector_num,
3861007b31SStefan Hajnoczi                                          QEMUIOVector *qiov,
3961007b31SStefan Hajnoczi                                          int nb_sectors,
4061007b31SStefan Hajnoczi                                          BdrvRequestFlags flags,
4161007b31SStefan Hajnoczi                                          BlockCompletionFunc *cb,
4261007b31SStefan Hajnoczi                                          void *opaque,
4361007b31SStefan Hajnoczi                                          bool is_write);
4461007b31SStefan Hajnoczi static void coroutine_fn bdrv_co_do_rw(void *opaque);
45*d05aa8bbSEric Blake static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
46*d05aa8bbSEric Blake     int64_t offset, int count, BdrvRequestFlags flags);
4761007b31SStefan Hajnoczi 
48c2066af0SKevin Wolf static void bdrv_parent_drained_begin(BlockDriverState *bs)
4961007b31SStefan Hajnoczi {
50c2066af0SKevin Wolf     BdrvChild *c;
5127ccdd52SKevin Wolf 
52c2066af0SKevin Wolf     QLIST_FOREACH(c, &bs->parents, next_parent) {
53c2066af0SKevin Wolf         if (c->role->drained_begin) {
54c2066af0SKevin Wolf             c->role->drained_begin(c);
55c2066af0SKevin Wolf         }
56ce0f1412SPaolo Bonzini     }
57ce0f1412SPaolo Bonzini }
58ce0f1412SPaolo Bonzini 
59c2066af0SKevin Wolf static void bdrv_parent_drained_end(BlockDriverState *bs)
60ce0f1412SPaolo Bonzini {
61c2066af0SKevin Wolf     BdrvChild *c;
6227ccdd52SKevin Wolf 
63c2066af0SKevin Wolf     QLIST_FOREACH(c, &bs->parents, next_parent) {
64c2066af0SKevin Wolf         if (c->role->drained_end) {
65c2066af0SKevin Wolf             c->role->drained_end(c);
6627ccdd52SKevin Wolf         }
67c2066af0SKevin Wolf     }
6861007b31SStefan Hajnoczi }
6961007b31SStefan Hajnoczi 
7061007b31SStefan Hajnoczi void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
7161007b31SStefan Hajnoczi {
7261007b31SStefan Hajnoczi     BlockDriver *drv = bs->drv;
7361007b31SStefan Hajnoczi     Error *local_err = NULL;
7461007b31SStefan Hajnoczi 
7561007b31SStefan Hajnoczi     memset(&bs->bl, 0, sizeof(bs->bl));
7661007b31SStefan Hajnoczi 
7761007b31SStefan Hajnoczi     if (!drv) {
7861007b31SStefan Hajnoczi         return;
7961007b31SStefan Hajnoczi     }
8061007b31SStefan Hajnoczi 
8161007b31SStefan Hajnoczi     /* Take some limits from the children as a default */
8261007b31SStefan Hajnoczi     if (bs->file) {
839a4f4c31SKevin Wolf         bdrv_refresh_limits(bs->file->bs, &local_err);
8461007b31SStefan Hajnoczi         if (local_err) {
8561007b31SStefan Hajnoczi             error_propagate(errp, local_err);
8661007b31SStefan Hajnoczi             return;
8761007b31SStefan Hajnoczi         }
889a4f4c31SKevin Wolf         bs->bl.opt_transfer_length = bs->file->bs->bl.opt_transfer_length;
899a4f4c31SKevin Wolf         bs->bl.max_transfer_length = bs->file->bs->bl.max_transfer_length;
909a4f4c31SKevin Wolf         bs->bl.min_mem_alignment = bs->file->bs->bl.min_mem_alignment;
919a4f4c31SKevin Wolf         bs->bl.opt_mem_alignment = bs->file->bs->bl.opt_mem_alignment;
92bd44feb7SStefan Hajnoczi         bs->bl.max_iov = bs->file->bs->bl.max_iov;
9361007b31SStefan Hajnoczi     } else {
944196d2f0SDenis V. Lunev         bs->bl.min_mem_alignment = 512;
95459b4e66SDenis V. Lunev         bs->bl.opt_mem_alignment = getpagesize();
96bd44feb7SStefan Hajnoczi 
97bd44feb7SStefan Hajnoczi         /* Safe default since most protocols use readv()/writev()/etc */
98bd44feb7SStefan Hajnoczi         bs->bl.max_iov = IOV_MAX;
9961007b31SStefan Hajnoczi     }
10061007b31SStefan Hajnoczi 
101760e0063SKevin Wolf     if (bs->backing) {
102760e0063SKevin Wolf         bdrv_refresh_limits(bs->backing->bs, &local_err);
10361007b31SStefan Hajnoczi         if (local_err) {
10461007b31SStefan Hajnoczi             error_propagate(errp, local_err);
10561007b31SStefan Hajnoczi             return;
10661007b31SStefan Hajnoczi         }
10761007b31SStefan Hajnoczi         bs->bl.opt_transfer_length =
10861007b31SStefan Hajnoczi             MAX(bs->bl.opt_transfer_length,
109760e0063SKevin Wolf                 bs->backing->bs->bl.opt_transfer_length);
11061007b31SStefan Hajnoczi         bs->bl.max_transfer_length =
11161007b31SStefan Hajnoczi             MIN_NON_ZERO(bs->bl.max_transfer_length,
112760e0063SKevin Wolf                          bs->backing->bs->bl.max_transfer_length);
11361007b31SStefan Hajnoczi         bs->bl.opt_mem_alignment =
11461007b31SStefan Hajnoczi             MAX(bs->bl.opt_mem_alignment,
115760e0063SKevin Wolf                 bs->backing->bs->bl.opt_mem_alignment);
1164196d2f0SDenis V. Lunev         bs->bl.min_mem_alignment =
1174196d2f0SDenis V. Lunev             MAX(bs->bl.min_mem_alignment,
118760e0063SKevin Wolf                 bs->backing->bs->bl.min_mem_alignment);
119bd44feb7SStefan Hajnoczi         bs->bl.max_iov =
120bd44feb7SStefan Hajnoczi             MIN(bs->bl.max_iov,
121bd44feb7SStefan Hajnoczi                 bs->backing->bs->bl.max_iov);
12261007b31SStefan Hajnoczi     }
12361007b31SStefan Hajnoczi 
12461007b31SStefan Hajnoczi     /* Then let the driver override it */
12561007b31SStefan Hajnoczi     if (drv->bdrv_refresh_limits) {
12661007b31SStefan Hajnoczi         drv->bdrv_refresh_limits(bs, errp);
12761007b31SStefan Hajnoczi     }
12861007b31SStefan Hajnoczi }
12961007b31SStefan Hajnoczi 
13061007b31SStefan Hajnoczi /**
13161007b31SStefan Hajnoczi  * The copy-on-read flag is actually a reference count so multiple users may
13261007b31SStefan Hajnoczi  * use the feature without worrying about clobbering its previous state.
13361007b31SStefan Hajnoczi  * Copy-on-read stays enabled until all users have called to disable it.
13461007b31SStefan Hajnoczi  */
13561007b31SStefan Hajnoczi void bdrv_enable_copy_on_read(BlockDriverState *bs)
13661007b31SStefan Hajnoczi {
13761007b31SStefan Hajnoczi     bs->copy_on_read++;
13861007b31SStefan Hajnoczi }
13961007b31SStefan Hajnoczi 
14061007b31SStefan Hajnoczi void bdrv_disable_copy_on_read(BlockDriverState *bs)
14161007b31SStefan Hajnoczi {
14261007b31SStefan Hajnoczi     assert(bs->copy_on_read > 0);
14361007b31SStefan Hajnoczi     bs->copy_on_read--;
14461007b31SStefan Hajnoczi }
14561007b31SStefan Hajnoczi 
14661007b31SStefan Hajnoczi /* Check if any requests are in-flight (including throttled requests) */
147439db28cSKevin Wolf bool bdrv_requests_pending(BlockDriverState *bs)
14861007b31SStefan Hajnoczi {
14937a639a7SKevin Wolf     BdrvChild *child;
15037a639a7SKevin Wolf 
15161007b31SStefan Hajnoczi     if (!QLIST_EMPTY(&bs->tracked_requests)) {
15261007b31SStefan Hajnoczi         return true;
15361007b31SStefan Hajnoczi     }
15437a639a7SKevin Wolf 
15537a639a7SKevin Wolf     QLIST_FOREACH(child, &bs->children, next) {
15637a639a7SKevin Wolf         if (bdrv_requests_pending(child->bs)) {
15761007b31SStefan Hajnoczi             return true;
15861007b31SStefan Hajnoczi         }
15961007b31SStefan Hajnoczi     }
16037a639a7SKevin Wolf 
16161007b31SStefan Hajnoczi     return false;
16261007b31SStefan Hajnoczi }
16361007b31SStefan Hajnoczi 
16467da1dc5SFam Zheng static void bdrv_drain_recurse(BlockDriverState *bs)
16567da1dc5SFam Zheng {
16667da1dc5SFam Zheng     BdrvChild *child;
16767da1dc5SFam Zheng 
16867da1dc5SFam Zheng     if (bs->drv && bs->drv->bdrv_drain) {
16967da1dc5SFam Zheng         bs->drv->bdrv_drain(bs);
17067da1dc5SFam Zheng     }
17167da1dc5SFam Zheng     QLIST_FOREACH(child, &bs->children, next) {
17267da1dc5SFam Zheng         bdrv_drain_recurse(child->bs);
17367da1dc5SFam Zheng     }
17467da1dc5SFam Zheng }
17567da1dc5SFam Zheng 
176a77fd4bbSFam Zheng typedef struct {
177a77fd4bbSFam Zheng     Coroutine *co;
178a77fd4bbSFam Zheng     BlockDriverState *bs;
179a77fd4bbSFam Zheng     QEMUBH *bh;
180a77fd4bbSFam Zheng     bool done;
181a77fd4bbSFam Zheng } BdrvCoDrainData;
182a77fd4bbSFam Zheng 
183b6e84c97SPaolo Bonzini static void bdrv_drain_poll(BlockDriverState *bs)
184b6e84c97SPaolo Bonzini {
185b6e84c97SPaolo Bonzini     bool busy = true;
186b6e84c97SPaolo Bonzini 
187b6e84c97SPaolo Bonzini     while (busy) {
188b6e84c97SPaolo Bonzini         /* Keep iterating */
189b6e84c97SPaolo Bonzini         busy = bdrv_requests_pending(bs);
190b6e84c97SPaolo Bonzini         busy |= aio_poll(bdrv_get_aio_context(bs), busy);
191b6e84c97SPaolo Bonzini     }
192b6e84c97SPaolo Bonzini }
193b6e84c97SPaolo Bonzini 
194a77fd4bbSFam Zheng static void bdrv_co_drain_bh_cb(void *opaque)
195a77fd4bbSFam Zheng {
196a77fd4bbSFam Zheng     BdrvCoDrainData *data = opaque;
197a77fd4bbSFam Zheng     Coroutine *co = data->co;
198a77fd4bbSFam Zheng 
199a77fd4bbSFam Zheng     qemu_bh_delete(data->bh);
200b6e84c97SPaolo Bonzini     bdrv_drain_poll(data->bs);
201a77fd4bbSFam Zheng     data->done = true;
202a77fd4bbSFam Zheng     qemu_coroutine_enter(co, NULL);
203a77fd4bbSFam Zheng }
204a77fd4bbSFam Zheng 
205b6e84c97SPaolo Bonzini static void coroutine_fn bdrv_co_yield_to_drain(BlockDriverState *bs)
206a77fd4bbSFam Zheng {
207a77fd4bbSFam Zheng     BdrvCoDrainData data;
208a77fd4bbSFam Zheng 
209a77fd4bbSFam Zheng     /* Calling bdrv_drain() from a BH ensures the current coroutine yields and
210a77fd4bbSFam Zheng      * other coroutines run if they were queued from
211a77fd4bbSFam Zheng      * qemu_co_queue_run_restart(). */
212a77fd4bbSFam Zheng 
213a77fd4bbSFam Zheng     assert(qemu_in_coroutine());
214a77fd4bbSFam Zheng     data = (BdrvCoDrainData) {
215a77fd4bbSFam Zheng         .co = qemu_coroutine_self(),
216a77fd4bbSFam Zheng         .bs = bs,
217a77fd4bbSFam Zheng         .done = false,
218a77fd4bbSFam Zheng         .bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_drain_bh_cb, &data),
219a77fd4bbSFam Zheng     };
220a77fd4bbSFam Zheng     qemu_bh_schedule(data.bh);
221a77fd4bbSFam Zheng 
222a77fd4bbSFam Zheng     qemu_coroutine_yield();
223a77fd4bbSFam Zheng     /* If we are resumed from some other event (such as an aio completion or a
224a77fd4bbSFam Zheng      * timer callback), it is a bug in the caller that should be fixed. */
225a77fd4bbSFam Zheng     assert(data.done);
226a77fd4bbSFam Zheng }
227a77fd4bbSFam Zheng 
2286820643fSKevin Wolf void bdrv_drained_begin(BlockDriverState *bs)
2296820643fSKevin Wolf {
2306820643fSKevin Wolf     if (!bs->quiesce_counter++) {
2316820643fSKevin Wolf         aio_disable_external(bdrv_get_aio_context(bs));
2326820643fSKevin Wolf         bdrv_parent_drained_begin(bs);
2336820643fSKevin Wolf     }
2346820643fSKevin Wolf 
2356820643fSKevin Wolf     bdrv_io_unplugged_begin(bs);
2366820643fSKevin Wolf     bdrv_drain_recurse(bs);
2376820643fSKevin Wolf     if (qemu_in_coroutine()) {
2386820643fSKevin Wolf         bdrv_co_yield_to_drain(bs);
2396820643fSKevin Wolf     } else {
2406820643fSKevin Wolf         bdrv_drain_poll(bs);
2416820643fSKevin Wolf     }
2426820643fSKevin Wolf     bdrv_io_unplugged_end(bs);
2436820643fSKevin Wolf }
2446820643fSKevin Wolf 
2456820643fSKevin Wolf void bdrv_drained_end(BlockDriverState *bs)
2466820643fSKevin Wolf {
2476820643fSKevin Wolf     assert(bs->quiesce_counter > 0);
2486820643fSKevin Wolf     if (--bs->quiesce_counter > 0) {
2496820643fSKevin Wolf         return;
2506820643fSKevin Wolf     }
2516820643fSKevin Wolf 
2526820643fSKevin Wolf     bdrv_parent_drained_end(bs);
2536820643fSKevin Wolf     aio_enable_external(bdrv_get_aio_context(bs));
2546820643fSKevin Wolf }
2556820643fSKevin Wolf 
25661007b31SStefan Hajnoczi /*
25767da1dc5SFam Zheng  * Wait for pending requests to complete on a single BlockDriverState subtree,
25867da1dc5SFam Zheng  * and suspend block driver's internal I/O until next request arrives.
25961007b31SStefan Hajnoczi  *
26061007b31SStefan Hajnoczi  * Note that unlike bdrv_drain_all(), the caller must hold the BlockDriverState
26161007b31SStefan Hajnoczi  * AioContext.
2627a63f3cdSStefan Hajnoczi  *
2637a63f3cdSStefan Hajnoczi  * Only this BlockDriverState's AioContext is run, so in-flight requests must
2647a63f3cdSStefan Hajnoczi  * not depend on events in other AioContexts.  In that case, use
2657a63f3cdSStefan Hajnoczi  * bdrv_drain_all() instead.
26661007b31SStefan Hajnoczi  */
267b6e84c97SPaolo Bonzini void coroutine_fn bdrv_co_drain(BlockDriverState *bs)
268b6e84c97SPaolo Bonzini {
2696820643fSKevin Wolf     assert(qemu_in_coroutine());
2706820643fSKevin Wolf     bdrv_drained_begin(bs);
2716820643fSKevin Wolf     bdrv_drained_end(bs);
272b6e84c97SPaolo Bonzini }
273b6e84c97SPaolo Bonzini 
27461007b31SStefan Hajnoczi void bdrv_drain(BlockDriverState *bs)
27561007b31SStefan Hajnoczi {
2766820643fSKevin Wolf     bdrv_drained_begin(bs);
2776820643fSKevin Wolf     bdrv_drained_end(bs);
27861007b31SStefan Hajnoczi }
27961007b31SStefan Hajnoczi 
28061007b31SStefan Hajnoczi /*
28161007b31SStefan Hajnoczi  * Wait for pending requests to complete across all BlockDriverStates
28261007b31SStefan Hajnoczi  *
28361007b31SStefan Hajnoczi  * This function does not flush data to disk, use bdrv_flush_all() for that
28461007b31SStefan Hajnoczi  * after calling this function.
28561007b31SStefan Hajnoczi  */
28661007b31SStefan Hajnoczi void bdrv_drain_all(void)
28761007b31SStefan Hajnoczi {
28861007b31SStefan Hajnoczi     /* Always run first iteration so any pending completion BHs run */
28961007b31SStefan Hajnoczi     bool busy = true;
2907c8eece4SKevin Wolf     BlockDriverState *bs;
29188be7b4bSKevin Wolf     BdrvNextIterator it;
292f406c03cSAlexander Yarygin     GSList *aio_ctxs = NULL, *ctx;
29361007b31SStefan Hajnoczi 
29488be7b4bSKevin Wolf     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
29561007b31SStefan Hajnoczi         AioContext *aio_context = bdrv_get_aio_context(bs);
29661007b31SStefan Hajnoczi 
29761007b31SStefan Hajnoczi         aio_context_acquire(aio_context);
29861007b31SStefan Hajnoczi         if (bs->job) {
29961007b31SStefan Hajnoczi             block_job_pause(bs->job);
30061007b31SStefan Hajnoczi         }
301c2066af0SKevin Wolf         bdrv_parent_drained_begin(bs);
3026b98bd64SPaolo Bonzini         bdrv_io_unplugged_begin(bs);
3039dcf8ecdSPaolo Bonzini         bdrv_drain_recurse(bs);
30461007b31SStefan Hajnoczi         aio_context_release(aio_context);
305f406c03cSAlexander Yarygin 
306764ba3aeSAlberto Garcia         if (!g_slist_find(aio_ctxs, aio_context)) {
307f406c03cSAlexander Yarygin             aio_ctxs = g_slist_prepend(aio_ctxs, aio_context);
308f406c03cSAlexander Yarygin         }
30961007b31SStefan Hajnoczi     }
31061007b31SStefan Hajnoczi 
3117a63f3cdSStefan Hajnoczi     /* Note that completion of an asynchronous I/O operation can trigger any
3127a63f3cdSStefan Hajnoczi      * number of other I/O operations on other devices---for example a
3137a63f3cdSStefan Hajnoczi      * coroutine can submit an I/O request to another device in response to
3147a63f3cdSStefan Hajnoczi      * request completion.  Therefore we must keep looping until there was no
3157a63f3cdSStefan Hajnoczi      * more activity rather than simply draining each device independently.
3167a63f3cdSStefan Hajnoczi      */
31761007b31SStefan Hajnoczi     while (busy) {
31861007b31SStefan Hajnoczi         busy = false;
319f406c03cSAlexander Yarygin 
320f406c03cSAlexander Yarygin         for (ctx = aio_ctxs; ctx != NULL; ctx = ctx->next) {
321f406c03cSAlexander Yarygin             AioContext *aio_context = ctx->data;
32261007b31SStefan Hajnoczi 
32361007b31SStefan Hajnoczi             aio_context_acquire(aio_context);
32488be7b4bSKevin Wolf             for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
325f406c03cSAlexander Yarygin                 if (aio_context == bdrv_get_aio_context(bs)) {
326f406c03cSAlexander Yarygin                     if (bdrv_requests_pending(bs)) {
327f406c03cSAlexander Yarygin                         busy = true;
328f406c03cSAlexander Yarygin                         aio_poll(aio_context, busy);
329f406c03cSAlexander Yarygin                     }
330f406c03cSAlexander Yarygin                 }
331f406c03cSAlexander Yarygin             }
332f406c03cSAlexander Yarygin             busy |= aio_poll(aio_context, false);
33361007b31SStefan Hajnoczi             aio_context_release(aio_context);
33461007b31SStefan Hajnoczi         }
33561007b31SStefan Hajnoczi     }
33661007b31SStefan Hajnoczi 
33788be7b4bSKevin Wolf     for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
33861007b31SStefan Hajnoczi         AioContext *aio_context = bdrv_get_aio_context(bs);
33961007b31SStefan Hajnoczi 
34061007b31SStefan Hajnoczi         aio_context_acquire(aio_context);
3416b98bd64SPaolo Bonzini         bdrv_io_unplugged_end(bs);
342c2066af0SKevin Wolf         bdrv_parent_drained_end(bs);
34361007b31SStefan Hajnoczi         if (bs->job) {
34461007b31SStefan Hajnoczi             block_job_resume(bs->job);
34561007b31SStefan Hajnoczi         }
34661007b31SStefan Hajnoczi         aio_context_release(aio_context);
34761007b31SStefan Hajnoczi     }
348f406c03cSAlexander Yarygin     g_slist_free(aio_ctxs);
34961007b31SStefan Hajnoczi }
35061007b31SStefan Hajnoczi 
35161007b31SStefan Hajnoczi /**
35261007b31SStefan Hajnoczi  * Remove an active request from the tracked requests list
35361007b31SStefan Hajnoczi  *
35461007b31SStefan Hajnoczi  * This function should be called when a tracked request is completing.
35561007b31SStefan Hajnoczi  */
35661007b31SStefan Hajnoczi static void tracked_request_end(BdrvTrackedRequest *req)
35761007b31SStefan Hajnoczi {
35861007b31SStefan Hajnoczi     if (req->serialising) {
35961007b31SStefan Hajnoczi         req->bs->serialising_in_flight--;
36061007b31SStefan Hajnoczi     }
36161007b31SStefan Hajnoczi 
36261007b31SStefan Hajnoczi     QLIST_REMOVE(req, list);
36361007b31SStefan Hajnoczi     qemu_co_queue_restart_all(&req->wait_queue);
36461007b31SStefan Hajnoczi }
36561007b31SStefan Hajnoczi 
36661007b31SStefan Hajnoczi /**
36761007b31SStefan Hajnoczi  * Add an active request to the tracked requests list
36861007b31SStefan Hajnoczi  */
36961007b31SStefan Hajnoczi static void tracked_request_begin(BdrvTrackedRequest *req,
37061007b31SStefan Hajnoczi                                   BlockDriverState *bs,
37161007b31SStefan Hajnoczi                                   int64_t offset,
372ebde595cSFam Zheng                                   unsigned int bytes,
373ebde595cSFam Zheng                                   enum BdrvTrackedRequestType type)
37461007b31SStefan Hajnoczi {
37561007b31SStefan Hajnoczi     *req = (BdrvTrackedRequest){
37661007b31SStefan Hajnoczi         .bs = bs,
37761007b31SStefan Hajnoczi         .offset         = offset,
37861007b31SStefan Hajnoczi         .bytes          = bytes,
379ebde595cSFam Zheng         .type           = type,
38061007b31SStefan Hajnoczi         .co             = qemu_coroutine_self(),
38161007b31SStefan Hajnoczi         .serialising    = false,
38261007b31SStefan Hajnoczi         .overlap_offset = offset,
38361007b31SStefan Hajnoczi         .overlap_bytes  = bytes,
38461007b31SStefan Hajnoczi     };
38561007b31SStefan Hajnoczi 
38661007b31SStefan Hajnoczi     qemu_co_queue_init(&req->wait_queue);
38761007b31SStefan Hajnoczi 
38861007b31SStefan Hajnoczi     QLIST_INSERT_HEAD(&bs->tracked_requests, req, list);
38961007b31SStefan Hajnoczi }
39061007b31SStefan Hajnoczi 
39161007b31SStefan Hajnoczi static void mark_request_serialising(BdrvTrackedRequest *req, uint64_t align)
39261007b31SStefan Hajnoczi {
39361007b31SStefan Hajnoczi     int64_t overlap_offset = req->offset & ~(align - 1);
39461007b31SStefan Hajnoczi     unsigned int overlap_bytes = ROUND_UP(req->offset + req->bytes, align)
39561007b31SStefan Hajnoczi                                - overlap_offset;
39661007b31SStefan Hajnoczi 
39761007b31SStefan Hajnoczi     if (!req->serialising) {
39861007b31SStefan Hajnoczi         req->bs->serialising_in_flight++;
39961007b31SStefan Hajnoczi         req->serialising = true;
40061007b31SStefan Hajnoczi     }
40161007b31SStefan Hajnoczi 
40261007b31SStefan Hajnoczi     req->overlap_offset = MIN(req->overlap_offset, overlap_offset);
40361007b31SStefan Hajnoczi     req->overlap_bytes = MAX(req->overlap_bytes, overlap_bytes);
40461007b31SStefan Hajnoczi }
40561007b31SStefan Hajnoczi 
40661007b31SStefan Hajnoczi /**
40761007b31SStefan Hajnoczi  * Round a region to cluster boundaries
40861007b31SStefan Hajnoczi  */
40961007b31SStefan Hajnoczi void bdrv_round_to_clusters(BlockDriverState *bs,
41061007b31SStefan Hajnoczi                             int64_t sector_num, int nb_sectors,
41161007b31SStefan Hajnoczi                             int64_t *cluster_sector_num,
41261007b31SStefan Hajnoczi                             int *cluster_nb_sectors)
41361007b31SStefan Hajnoczi {
41461007b31SStefan Hajnoczi     BlockDriverInfo bdi;
41561007b31SStefan Hajnoczi 
41661007b31SStefan Hajnoczi     if (bdrv_get_info(bs, &bdi) < 0 || bdi.cluster_size == 0) {
41761007b31SStefan Hajnoczi         *cluster_sector_num = sector_num;
41861007b31SStefan Hajnoczi         *cluster_nb_sectors = nb_sectors;
41961007b31SStefan Hajnoczi     } else {
42061007b31SStefan Hajnoczi         int64_t c = bdi.cluster_size / BDRV_SECTOR_SIZE;
42161007b31SStefan Hajnoczi         *cluster_sector_num = QEMU_ALIGN_DOWN(sector_num, c);
42261007b31SStefan Hajnoczi         *cluster_nb_sectors = QEMU_ALIGN_UP(sector_num - *cluster_sector_num +
42361007b31SStefan Hajnoczi                                             nb_sectors, c);
42461007b31SStefan Hajnoczi     }
42561007b31SStefan Hajnoczi }
42661007b31SStefan Hajnoczi 
42761007b31SStefan Hajnoczi static int bdrv_get_cluster_size(BlockDriverState *bs)
42861007b31SStefan Hajnoczi {
42961007b31SStefan Hajnoczi     BlockDriverInfo bdi;
43061007b31SStefan Hajnoczi     int ret;
43161007b31SStefan Hajnoczi 
43261007b31SStefan Hajnoczi     ret = bdrv_get_info(bs, &bdi);
43361007b31SStefan Hajnoczi     if (ret < 0 || bdi.cluster_size == 0) {
43461007b31SStefan Hajnoczi         return bs->request_alignment;
43561007b31SStefan Hajnoczi     } else {
43661007b31SStefan Hajnoczi         return bdi.cluster_size;
43761007b31SStefan Hajnoczi     }
43861007b31SStefan Hajnoczi }
43961007b31SStefan Hajnoczi 
44061007b31SStefan Hajnoczi static bool tracked_request_overlaps(BdrvTrackedRequest *req,
44161007b31SStefan Hajnoczi                                      int64_t offset, unsigned int bytes)
44261007b31SStefan Hajnoczi {
44361007b31SStefan Hajnoczi     /*        aaaa   bbbb */
44461007b31SStefan Hajnoczi     if (offset >= req->overlap_offset + req->overlap_bytes) {
44561007b31SStefan Hajnoczi         return false;
44661007b31SStefan Hajnoczi     }
44761007b31SStefan Hajnoczi     /* bbbb   aaaa        */
44861007b31SStefan Hajnoczi     if (req->overlap_offset >= offset + bytes) {
44961007b31SStefan Hajnoczi         return false;
45061007b31SStefan Hajnoczi     }
45161007b31SStefan Hajnoczi     return true;
45261007b31SStefan Hajnoczi }
45361007b31SStefan Hajnoczi 
45461007b31SStefan Hajnoczi static bool coroutine_fn wait_serialising_requests(BdrvTrackedRequest *self)
45561007b31SStefan Hajnoczi {
45661007b31SStefan Hajnoczi     BlockDriverState *bs = self->bs;
45761007b31SStefan Hajnoczi     BdrvTrackedRequest *req;
45861007b31SStefan Hajnoczi     bool retry;
45961007b31SStefan Hajnoczi     bool waited = false;
46061007b31SStefan Hajnoczi 
46161007b31SStefan Hajnoczi     if (!bs->serialising_in_flight) {
46261007b31SStefan Hajnoczi         return false;
46361007b31SStefan Hajnoczi     }
46461007b31SStefan Hajnoczi 
46561007b31SStefan Hajnoczi     do {
46661007b31SStefan Hajnoczi         retry = false;
46761007b31SStefan Hajnoczi         QLIST_FOREACH(req, &bs->tracked_requests, list) {
46861007b31SStefan Hajnoczi             if (req == self || (!req->serialising && !self->serialising)) {
46961007b31SStefan Hajnoczi                 continue;
47061007b31SStefan Hajnoczi             }
47161007b31SStefan Hajnoczi             if (tracked_request_overlaps(req, self->overlap_offset,
47261007b31SStefan Hajnoczi                                          self->overlap_bytes))
47361007b31SStefan Hajnoczi             {
47461007b31SStefan Hajnoczi                 /* Hitting this means there was a reentrant request, for
47561007b31SStefan Hajnoczi                  * example, a block driver issuing nested requests.  This must
47661007b31SStefan Hajnoczi                  * never happen since it means deadlock.
47761007b31SStefan Hajnoczi                  */
47861007b31SStefan Hajnoczi                 assert(qemu_coroutine_self() != req->co);
47961007b31SStefan Hajnoczi 
48061007b31SStefan Hajnoczi                 /* If the request is already (indirectly) waiting for us, or
48161007b31SStefan Hajnoczi                  * will wait for us as soon as it wakes up, then just go on
48261007b31SStefan Hajnoczi                  * (instead of producing a deadlock in the former case). */
48361007b31SStefan Hajnoczi                 if (!req->waiting_for) {
48461007b31SStefan Hajnoczi                     self->waiting_for = req;
48561007b31SStefan Hajnoczi                     qemu_co_queue_wait(&req->wait_queue);
48661007b31SStefan Hajnoczi                     self->waiting_for = NULL;
48761007b31SStefan Hajnoczi                     retry = true;
48861007b31SStefan Hajnoczi                     waited = true;
48961007b31SStefan Hajnoczi                     break;
49061007b31SStefan Hajnoczi                 }
49161007b31SStefan Hajnoczi             }
49261007b31SStefan Hajnoczi         }
49361007b31SStefan Hajnoczi     } while (retry);
49461007b31SStefan Hajnoczi 
49561007b31SStefan Hajnoczi     return waited;
49661007b31SStefan Hajnoczi }
49761007b31SStefan Hajnoczi 
49861007b31SStefan Hajnoczi static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
49961007b31SStefan Hajnoczi                                    size_t size)
50061007b31SStefan Hajnoczi {
50161007b31SStefan Hajnoczi     if (size > BDRV_REQUEST_MAX_SECTORS << BDRV_SECTOR_BITS) {
50261007b31SStefan Hajnoczi         return -EIO;
50361007b31SStefan Hajnoczi     }
50461007b31SStefan Hajnoczi 
50561007b31SStefan Hajnoczi     if (!bdrv_is_inserted(bs)) {
50661007b31SStefan Hajnoczi         return -ENOMEDIUM;
50761007b31SStefan Hajnoczi     }
50861007b31SStefan Hajnoczi 
50961007b31SStefan Hajnoczi     if (offset < 0) {
51061007b31SStefan Hajnoczi         return -EIO;
51161007b31SStefan Hajnoczi     }
51261007b31SStefan Hajnoczi 
51361007b31SStefan Hajnoczi     return 0;
51461007b31SStefan Hajnoczi }
51561007b31SStefan Hajnoczi 
51661007b31SStefan Hajnoczi static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
51761007b31SStefan Hajnoczi                               int nb_sectors)
51861007b31SStefan Hajnoczi {
51961007b31SStefan Hajnoczi     if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
52061007b31SStefan Hajnoczi         return -EIO;
52161007b31SStefan Hajnoczi     }
52261007b31SStefan Hajnoczi 
52361007b31SStefan Hajnoczi     return bdrv_check_byte_request(bs, sector_num * BDRV_SECTOR_SIZE,
52461007b31SStefan Hajnoczi                                    nb_sectors * BDRV_SECTOR_SIZE);
52561007b31SStefan Hajnoczi }
52661007b31SStefan Hajnoczi 
52761007b31SStefan Hajnoczi typedef struct RwCo {
52861007b31SStefan Hajnoczi     BlockDriverState *bs;
52961007b31SStefan Hajnoczi     int64_t offset;
53061007b31SStefan Hajnoczi     QEMUIOVector *qiov;
53161007b31SStefan Hajnoczi     bool is_write;
53261007b31SStefan Hajnoczi     int ret;
53361007b31SStefan Hajnoczi     BdrvRequestFlags flags;
53461007b31SStefan Hajnoczi } RwCo;
53561007b31SStefan Hajnoczi 
53661007b31SStefan Hajnoczi static void coroutine_fn bdrv_rw_co_entry(void *opaque)
53761007b31SStefan Hajnoczi {
53861007b31SStefan Hajnoczi     RwCo *rwco = opaque;
53961007b31SStefan Hajnoczi 
54061007b31SStefan Hajnoczi     if (!rwco->is_write) {
541cab3a356SKevin Wolf         rwco->ret = bdrv_co_preadv(rwco->bs, rwco->offset,
54261007b31SStefan Hajnoczi                                    rwco->qiov->size, rwco->qiov,
54361007b31SStefan Hajnoczi                                    rwco->flags);
54461007b31SStefan Hajnoczi     } else {
545cab3a356SKevin Wolf         rwco->ret = bdrv_co_pwritev(rwco->bs, rwco->offset,
54661007b31SStefan Hajnoczi                                     rwco->qiov->size, rwco->qiov,
54761007b31SStefan Hajnoczi                                     rwco->flags);
54861007b31SStefan Hajnoczi     }
54961007b31SStefan Hajnoczi }
55061007b31SStefan Hajnoczi 
55161007b31SStefan Hajnoczi /*
55261007b31SStefan Hajnoczi  * Process a vectored synchronous request using coroutines
55361007b31SStefan Hajnoczi  */
55461007b31SStefan Hajnoczi static int bdrv_prwv_co(BlockDriverState *bs, int64_t offset,
55561007b31SStefan Hajnoczi                         QEMUIOVector *qiov, bool is_write,
55661007b31SStefan Hajnoczi                         BdrvRequestFlags flags)
55761007b31SStefan Hajnoczi {
55861007b31SStefan Hajnoczi     Coroutine *co;
55961007b31SStefan Hajnoczi     RwCo rwco = {
56061007b31SStefan Hajnoczi         .bs = bs,
56161007b31SStefan Hajnoczi         .offset = offset,
56261007b31SStefan Hajnoczi         .qiov = qiov,
56361007b31SStefan Hajnoczi         .is_write = is_write,
56461007b31SStefan Hajnoczi         .ret = NOT_DONE,
56561007b31SStefan Hajnoczi         .flags = flags,
56661007b31SStefan Hajnoczi     };
56761007b31SStefan Hajnoczi 
56861007b31SStefan Hajnoczi     if (qemu_in_coroutine()) {
56961007b31SStefan Hajnoczi         /* Fast-path if already in coroutine context */
57061007b31SStefan Hajnoczi         bdrv_rw_co_entry(&rwco);
57161007b31SStefan Hajnoczi     } else {
57261007b31SStefan Hajnoczi         AioContext *aio_context = bdrv_get_aio_context(bs);
57361007b31SStefan Hajnoczi 
57461007b31SStefan Hajnoczi         co = qemu_coroutine_create(bdrv_rw_co_entry);
57561007b31SStefan Hajnoczi         qemu_coroutine_enter(co, &rwco);
57661007b31SStefan Hajnoczi         while (rwco.ret == NOT_DONE) {
57761007b31SStefan Hajnoczi             aio_poll(aio_context, true);
57861007b31SStefan Hajnoczi         }
57961007b31SStefan Hajnoczi     }
58061007b31SStefan Hajnoczi     return rwco.ret;
58161007b31SStefan Hajnoczi }
58261007b31SStefan Hajnoczi 
58361007b31SStefan Hajnoczi /*
58461007b31SStefan Hajnoczi  * Process a synchronous request using coroutines
58561007b31SStefan Hajnoczi  */
58661007b31SStefan Hajnoczi static int bdrv_rw_co(BlockDriverState *bs, int64_t sector_num, uint8_t *buf,
58761007b31SStefan Hajnoczi                       int nb_sectors, bool is_write, BdrvRequestFlags flags)
58861007b31SStefan Hajnoczi {
58961007b31SStefan Hajnoczi     QEMUIOVector qiov;
59061007b31SStefan Hajnoczi     struct iovec iov = {
59161007b31SStefan Hajnoczi         .iov_base = (void *)buf,
59261007b31SStefan Hajnoczi         .iov_len = nb_sectors * BDRV_SECTOR_SIZE,
59361007b31SStefan Hajnoczi     };
59461007b31SStefan Hajnoczi 
59561007b31SStefan Hajnoczi     if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
59661007b31SStefan Hajnoczi         return -EINVAL;
59761007b31SStefan Hajnoczi     }
59861007b31SStefan Hajnoczi 
59961007b31SStefan Hajnoczi     qemu_iovec_init_external(&qiov, &iov, 1);
60061007b31SStefan Hajnoczi     return bdrv_prwv_co(bs, sector_num << BDRV_SECTOR_BITS,
60161007b31SStefan Hajnoczi                         &qiov, is_write, flags);
60261007b31SStefan Hajnoczi }
60361007b31SStefan Hajnoczi 
60461007b31SStefan Hajnoczi /* return < 0 if error. See bdrv_write() for the return codes */
60561007b31SStefan Hajnoczi int bdrv_read(BlockDriverState *bs, int64_t sector_num,
60661007b31SStefan Hajnoczi               uint8_t *buf, int nb_sectors)
60761007b31SStefan Hajnoczi {
60861007b31SStefan Hajnoczi     return bdrv_rw_co(bs, sector_num, buf, nb_sectors, false, 0);
60961007b31SStefan Hajnoczi }
61061007b31SStefan Hajnoczi 
61161007b31SStefan Hajnoczi /* Return < 0 if error. Important errors are:
61261007b31SStefan Hajnoczi   -EIO         generic I/O error (may happen for all errors)
61361007b31SStefan Hajnoczi   -ENOMEDIUM   No media inserted.
61461007b31SStefan Hajnoczi   -EINVAL      Invalid sector number or nb_sectors
61561007b31SStefan Hajnoczi   -EACCES      Trying to write a read-only device
61661007b31SStefan Hajnoczi */
61761007b31SStefan Hajnoczi int bdrv_write(BlockDriverState *bs, int64_t sector_num,
61861007b31SStefan Hajnoczi                const uint8_t *buf, int nb_sectors)
61961007b31SStefan Hajnoczi {
62061007b31SStefan Hajnoczi     return bdrv_rw_co(bs, sector_num, (uint8_t *)buf, nb_sectors, true, 0);
62161007b31SStefan Hajnoczi }
62261007b31SStefan Hajnoczi 
62361007b31SStefan Hajnoczi int bdrv_write_zeroes(BlockDriverState *bs, int64_t sector_num,
62461007b31SStefan Hajnoczi                       int nb_sectors, BdrvRequestFlags flags)
62561007b31SStefan Hajnoczi {
62661007b31SStefan Hajnoczi     return bdrv_rw_co(bs, sector_num, NULL, nb_sectors, true,
62761007b31SStefan Hajnoczi                       BDRV_REQ_ZERO_WRITE | flags);
62861007b31SStefan Hajnoczi }
62961007b31SStefan Hajnoczi 
63061007b31SStefan Hajnoczi /*
63161007b31SStefan Hajnoczi  * Completely zero out a block device with the help of bdrv_write_zeroes.
63261007b31SStefan Hajnoczi  * The operation is sped up by checking the block status and only writing
63361007b31SStefan Hajnoczi  * zeroes to the device if they currently do not return zeroes. Optional
634465fe887SEric Blake  * flags are passed through to bdrv_write_zeroes (e.g. BDRV_REQ_MAY_UNMAP,
635465fe887SEric Blake  * BDRV_REQ_FUA).
63661007b31SStefan Hajnoczi  *
63761007b31SStefan Hajnoczi  * Returns < 0 on error, 0 on success. For error codes see bdrv_write().
63861007b31SStefan Hajnoczi  */
63961007b31SStefan Hajnoczi int bdrv_make_zero(BlockDriverState *bs, BdrvRequestFlags flags)
64061007b31SStefan Hajnoczi {
64161007b31SStefan Hajnoczi     int64_t target_sectors, ret, nb_sectors, sector_num = 0;
64267a0fd2aSFam Zheng     BlockDriverState *file;
64361007b31SStefan Hajnoczi     int n;
64461007b31SStefan Hajnoczi 
64561007b31SStefan Hajnoczi     target_sectors = bdrv_nb_sectors(bs);
64661007b31SStefan Hajnoczi     if (target_sectors < 0) {
64761007b31SStefan Hajnoczi         return target_sectors;
64861007b31SStefan Hajnoczi     }
64961007b31SStefan Hajnoczi 
65061007b31SStefan Hajnoczi     for (;;) {
65161007b31SStefan Hajnoczi         nb_sectors = MIN(target_sectors - sector_num, BDRV_REQUEST_MAX_SECTORS);
65261007b31SStefan Hajnoczi         if (nb_sectors <= 0) {
65361007b31SStefan Hajnoczi             return 0;
65461007b31SStefan Hajnoczi         }
65567a0fd2aSFam Zheng         ret = bdrv_get_block_status(bs, sector_num, nb_sectors, &n, &file);
65661007b31SStefan Hajnoczi         if (ret < 0) {
65761007b31SStefan Hajnoczi             error_report("error getting block status at sector %" PRId64 ": %s",
65861007b31SStefan Hajnoczi                          sector_num, strerror(-ret));
65961007b31SStefan Hajnoczi             return ret;
66061007b31SStefan Hajnoczi         }
66161007b31SStefan Hajnoczi         if (ret & BDRV_BLOCK_ZERO) {
66261007b31SStefan Hajnoczi             sector_num += n;
66361007b31SStefan Hajnoczi             continue;
66461007b31SStefan Hajnoczi         }
66561007b31SStefan Hajnoczi         ret = bdrv_write_zeroes(bs, sector_num, n, flags);
66661007b31SStefan Hajnoczi         if (ret < 0) {
66761007b31SStefan Hajnoczi             error_report("error writing zeroes at sector %" PRId64 ": %s",
66861007b31SStefan Hajnoczi                          sector_num, strerror(-ret));
66961007b31SStefan Hajnoczi             return ret;
67061007b31SStefan Hajnoczi         }
67161007b31SStefan Hajnoczi         sector_num += n;
67261007b31SStefan Hajnoczi     }
67361007b31SStefan Hajnoczi }
67461007b31SStefan Hajnoczi 
67561007b31SStefan Hajnoczi int bdrv_pread(BlockDriverState *bs, int64_t offset, void *buf, int bytes)
67661007b31SStefan Hajnoczi {
67761007b31SStefan Hajnoczi     QEMUIOVector qiov;
67861007b31SStefan Hajnoczi     struct iovec iov = {
67961007b31SStefan Hajnoczi         .iov_base = (void *)buf,
68061007b31SStefan Hajnoczi         .iov_len = bytes,
68161007b31SStefan Hajnoczi     };
68261007b31SStefan Hajnoczi     int ret;
68361007b31SStefan Hajnoczi 
68461007b31SStefan Hajnoczi     if (bytes < 0) {
68561007b31SStefan Hajnoczi         return -EINVAL;
68661007b31SStefan Hajnoczi     }
68761007b31SStefan Hajnoczi 
68861007b31SStefan Hajnoczi     qemu_iovec_init_external(&qiov, &iov, 1);
68961007b31SStefan Hajnoczi     ret = bdrv_prwv_co(bs, offset, &qiov, false, 0);
69061007b31SStefan Hajnoczi     if (ret < 0) {
69161007b31SStefan Hajnoczi         return ret;
69261007b31SStefan Hajnoczi     }
69361007b31SStefan Hajnoczi 
69461007b31SStefan Hajnoczi     return bytes;
69561007b31SStefan Hajnoczi }
69661007b31SStefan Hajnoczi 
69761007b31SStefan Hajnoczi int bdrv_pwritev(BlockDriverState *bs, int64_t offset, QEMUIOVector *qiov)
69861007b31SStefan Hajnoczi {
69961007b31SStefan Hajnoczi     int ret;
70061007b31SStefan Hajnoczi 
70161007b31SStefan Hajnoczi     ret = bdrv_prwv_co(bs, offset, qiov, true, 0);
70261007b31SStefan Hajnoczi     if (ret < 0) {
70361007b31SStefan Hajnoczi         return ret;
70461007b31SStefan Hajnoczi     }
70561007b31SStefan Hajnoczi 
70661007b31SStefan Hajnoczi     return qiov->size;
70761007b31SStefan Hajnoczi }
70861007b31SStefan Hajnoczi 
70961007b31SStefan Hajnoczi int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
71061007b31SStefan Hajnoczi                 const void *buf, int bytes)
71161007b31SStefan Hajnoczi {
71261007b31SStefan Hajnoczi     QEMUIOVector qiov;
71361007b31SStefan Hajnoczi     struct iovec iov = {
71461007b31SStefan Hajnoczi         .iov_base   = (void *) buf,
71561007b31SStefan Hajnoczi         .iov_len    = bytes,
71661007b31SStefan Hajnoczi     };
71761007b31SStefan Hajnoczi 
71861007b31SStefan Hajnoczi     if (bytes < 0) {
71961007b31SStefan Hajnoczi         return -EINVAL;
72061007b31SStefan Hajnoczi     }
72161007b31SStefan Hajnoczi 
72261007b31SStefan Hajnoczi     qemu_iovec_init_external(&qiov, &iov, 1);
72361007b31SStefan Hajnoczi     return bdrv_pwritev(bs, offset, &qiov);
72461007b31SStefan Hajnoczi }
72561007b31SStefan Hajnoczi 
72661007b31SStefan Hajnoczi /*
72761007b31SStefan Hajnoczi  * Writes to the file and ensures that no writes are reordered across this
72861007b31SStefan Hajnoczi  * request (acts as a barrier)
72961007b31SStefan Hajnoczi  *
73061007b31SStefan Hajnoczi  * Returns 0 on success, -errno in error cases.
73161007b31SStefan Hajnoczi  */
73261007b31SStefan Hajnoczi int bdrv_pwrite_sync(BlockDriverState *bs, int64_t offset,
73361007b31SStefan Hajnoczi     const void *buf, int count)
73461007b31SStefan Hajnoczi {
73561007b31SStefan Hajnoczi     int ret;
73661007b31SStefan Hajnoczi 
73761007b31SStefan Hajnoczi     ret = bdrv_pwrite(bs, offset, buf, count);
73861007b31SStefan Hajnoczi     if (ret < 0) {
73961007b31SStefan Hajnoczi         return ret;
74061007b31SStefan Hajnoczi     }
74161007b31SStefan Hajnoczi 
742855a6a93SKevin Wolf     ret = bdrv_flush(bs);
743855a6a93SKevin Wolf     if (ret < 0) {
744855a6a93SKevin Wolf         return ret;
74561007b31SStefan Hajnoczi     }
74661007b31SStefan Hajnoczi 
74761007b31SStefan Hajnoczi     return 0;
74861007b31SStefan Hajnoczi }
74961007b31SStefan Hajnoczi 
75008844473SKevin Wolf typedef struct CoroutineIOCompletion {
75108844473SKevin Wolf     Coroutine *coroutine;
75208844473SKevin Wolf     int ret;
75308844473SKevin Wolf } CoroutineIOCompletion;
75408844473SKevin Wolf 
75508844473SKevin Wolf static void bdrv_co_io_em_complete(void *opaque, int ret)
75608844473SKevin Wolf {
75708844473SKevin Wolf     CoroutineIOCompletion *co = opaque;
75808844473SKevin Wolf 
75908844473SKevin Wolf     co->ret = ret;
76008844473SKevin Wolf     qemu_coroutine_enter(co->coroutine, NULL);
76108844473SKevin Wolf }
76208844473SKevin Wolf 
763166fe960SKevin Wolf static int coroutine_fn bdrv_driver_preadv(BlockDriverState *bs,
764166fe960SKevin Wolf                                            uint64_t offset, uint64_t bytes,
765166fe960SKevin Wolf                                            QEMUIOVector *qiov, int flags)
766166fe960SKevin Wolf {
767166fe960SKevin Wolf     BlockDriver *drv = bs->drv;
7683fb06697SKevin Wolf     int64_t sector_num;
7693fb06697SKevin Wolf     unsigned int nb_sectors;
7703fb06697SKevin Wolf 
7713fb06697SKevin Wolf     if (drv->bdrv_co_preadv) {
7723fb06697SKevin Wolf         return drv->bdrv_co_preadv(bs, offset, bytes, qiov, flags);
7733fb06697SKevin Wolf     }
7743fb06697SKevin Wolf 
7753fb06697SKevin Wolf     sector_num = offset >> BDRV_SECTOR_BITS;
7763fb06697SKevin Wolf     nb_sectors = bytes >> BDRV_SECTOR_BITS;
777166fe960SKevin Wolf 
778166fe960SKevin Wolf     assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
779166fe960SKevin Wolf     assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
780166fe960SKevin Wolf     assert((bytes >> BDRV_SECTOR_BITS) <= BDRV_REQUEST_MAX_SECTORS);
781166fe960SKevin Wolf 
78208844473SKevin Wolf     if (drv->bdrv_co_readv) {
783166fe960SKevin Wolf         return drv->bdrv_co_readv(bs, sector_num, nb_sectors, qiov);
78408844473SKevin Wolf     } else {
78508844473SKevin Wolf         BlockAIOCB *acb;
78608844473SKevin Wolf         CoroutineIOCompletion co = {
78708844473SKevin Wolf             .coroutine = qemu_coroutine_self(),
78808844473SKevin Wolf         };
78908844473SKevin Wolf 
79008844473SKevin Wolf         acb = bs->drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
79108844473SKevin Wolf                                       bdrv_co_io_em_complete, &co);
79208844473SKevin Wolf         if (acb == NULL) {
79308844473SKevin Wolf             return -EIO;
79408844473SKevin Wolf         } else {
79508844473SKevin Wolf             qemu_coroutine_yield();
79608844473SKevin Wolf             return co.ret;
79708844473SKevin Wolf         }
79808844473SKevin Wolf     }
799166fe960SKevin Wolf }
800166fe960SKevin Wolf 
80178a07294SKevin Wolf static int coroutine_fn bdrv_driver_pwritev(BlockDriverState *bs,
80278a07294SKevin Wolf                                             uint64_t offset, uint64_t bytes,
80378a07294SKevin Wolf                                             QEMUIOVector *qiov, int flags)
80478a07294SKevin Wolf {
80578a07294SKevin Wolf     BlockDriver *drv = bs->drv;
8063fb06697SKevin Wolf     int64_t sector_num;
8073fb06697SKevin Wolf     unsigned int nb_sectors;
80878a07294SKevin Wolf     int ret;
80978a07294SKevin Wolf 
8103fb06697SKevin Wolf     if (drv->bdrv_co_pwritev) {
8113fb06697SKevin Wolf         ret = drv->bdrv_co_pwritev(bs, offset, bytes, qiov, flags);
8123fb06697SKevin Wolf         goto emulate_flags;
8133fb06697SKevin Wolf     }
8143fb06697SKevin Wolf 
8153fb06697SKevin Wolf     sector_num = offset >> BDRV_SECTOR_BITS;
8163fb06697SKevin Wolf     nb_sectors = bytes >> BDRV_SECTOR_BITS;
8173fb06697SKevin Wolf 
81878a07294SKevin Wolf     assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
81978a07294SKevin Wolf     assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
82078a07294SKevin Wolf     assert((bytes >> BDRV_SECTOR_BITS) <= BDRV_REQUEST_MAX_SECTORS);
82178a07294SKevin Wolf 
82278a07294SKevin Wolf     if (drv->bdrv_co_writev_flags) {
82378a07294SKevin Wolf         ret = drv->bdrv_co_writev_flags(bs, sector_num, nb_sectors, qiov,
8244df863f3SEric Blake                                         flags & bs->supported_write_flags);
8254df863f3SEric Blake         flags &= ~bs->supported_write_flags;
82608844473SKevin Wolf     } else if (drv->bdrv_co_writev) {
8274df863f3SEric Blake         assert(!bs->supported_write_flags);
82878a07294SKevin Wolf         ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
82908844473SKevin Wolf     } else {
83008844473SKevin Wolf         BlockAIOCB *acb;
83108844473SKevin Wolf         CoroutineIOCompletion co = {
83208844473SKevin Wolf             .coroutine = qemu_coroutine_self(),
83308844473SKevin Wolf         };
83408844473SKevin Wolf 
83508844473SKevin Wolf         acb = bs->drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
83608844473SKevin Wolf                                        bdrv_co_io_em_complete, &co);
83708844473SKevin Wolf         if (acb == NULL) {
8383fb06697SKevin Wolf             ret = -EIO;
83908844473SKevin Wolf         } else {
84008844473SKevin Wolf             qemu_coroutine_yield();
8413fb06697SKevin Wolf             ret = co.ret;
84208844473SKevin Wolf         }
84378a07294SKevin Wolf     }
84478a07294SKevin Wolf 
8453fb06697SKevin Wolf emulate_flags:
8464df863f3SEric Blake     if (ret == 0 && (flags & BDRV_REQ_FUA)) {
84778a07294SKevin Wolf         ret = bdrv_co_flush(bs);
84878a07294SKevin Wolf     }
84978a07294SKevin Wolf 
85078a07294SKevin Wolf     return ret;
85178a07294SKevin Wolf }
85278a07294SKevin Wolf 
85361007b31SStefan Hajnoczi static int coroutine_fn bdrv_co_do_copy_on_readv(BlockDriverState *bs,
85461007b31SStefan Hajnoczi         int64_t sector_num, int nb_sectors, QEMUIOVector *qiov)
85561007b31SStefan Hajnoczi {
85661007b31SStefan Hajnoczi     /* Perform I/O through a temporary buffer so that users who scribble over
85761007b31SStefan Hajnoczi      * their read buffer while the operation is in progress do not end up
85861007b31SStefan Hajnoczi      * modifying the image file.  This is critical for zero-copy guest I/O
85961007b31SStefan Hajnoczi      * where anything might happen inside guest memory.
86061007b31SStefan Hajnoczi      */
86161007b31SStefan Hajnoczi     void *bounce_buffer;
86261007b31SStefan Hajnoczi 
86361007b31SStefan Hajnoczi     BlockDriver *drv = bs->drv;
86461007b31SStefan Hajnoczi     struct iovec iov;
86561007b31SStefan Hajnoczi     QEMUIOVector bounce_qiov;
86661007b31SStefan Hajnoczi     int64_t cluster_sector_num;
86761007b31SStefan Hajnoczi     int cluster_nb_sectors;
86861007b31SStefan Hajnoczi     size_t skip_bytes;
86961007b31SStefan Hajnoczi     int ret;
87061007b31SStefan Hajnoczi 
87161007b31SStefan Hajnoczi     /* Cover entire cluster so no additional backing file I/O is required when
87261007b31SStefan Hajnoczi      * allocating cluster in the image file.
87361007b31SStefan Hajnoczi      */
87461007b31SStefan Hajnoczi     bdrv_round_to_clusters(bs, sector_num, nb_sectors,
87561007b31SStefan Hajnoczi                            &cluster_sector_num, &cluster_nb_sectors);
87661007b31SStefan Hajnoczi 
87761007b31SStefan Hajnoczi     trace_bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors,
87861007b31SStefan Hajnoczi                                    cluster_sector_num, cluster_nb_sectors);
87961007b31SStefan Hajnoczi 
88061007b31SStefan Hajnoczi     iov.iov_len = cluster_nb_sectors * BDRV_SECTOR_SIZE;
88161007b31SStefan Hajnoczi     iov.iov_base = bounce_buffer = qemu_try_blockalign(bs, iov.iov_len);
88261007b31SStefan Hajnoczi     if (bounce_buffer == NULL) {
88361007b31SStefan Hajnoczi         ret = -ENOMEM;
88461007b31SStefan Hajnoczi         goto err;
88561007b31SStefan Hajnoczi     }
88661007b31SStefan Hajnoczi 
88761007b31SStefan Hajnoczi     qemu_iovec_init_external(&bounce_qiov, &iov, 1);
88861007b31SStefan Hajnoczi 
889166fe960SKevin Wolf     ret = bdrv_driver_preadv(bs, cluster_sector_num * BDRV_SECTOR_SIZE,
890166fe960SKevin Wolf                              cluster_nb_sectors * BDRV_SECTOR_SIZE,
891166fe960SKevin Wolf                              &bounce_qiov, 0);
89261007b31SStefan Hajnoczi     if (ret < 0) {
89361007b31SStefan Hajnoczi         goto err;
89461007b31SStefan Hajnoczi     }
89561007b31SStefan Hajnoczi 
896*d05aa8bbSEric Blake     if ((drv->bdrv_co_write_zeroes || drv->bdrv_co_pwrite_zeroes) &&
89761007b31SStefan Hajnoczi         buffer_is_zero(bounce_buffer, iov.iov_len)) {
898*d05aa8bbSEric Blake         ret = bdrv_co_do_pwrite_zeroes(bs,
899*d05aa8bbSEric Blake                                        cluster_sector_num * BDRV_SECTOR_SIZE,
900*d05aa8bbSEric Blake                                        cluster_nb_sectors * BDRV_SECTOR_SIZE,
901*d05aa8bbSEric Blake                                        0);
90261007b31SStefan Hajnoczi     } else {
90361007b31SStefan Hajnoczi         /* This does not change the data on the disk, it is not necessary
90461007b31SStefan Hajnoczi          * to flush even in cache=writethrough mode.
90561007b31SStefan Hajnoczi          */
90678a07294SKevin Wolf         ret = bdrv_driver_pwritev(bs, cluster_sector_num * BDRV_SECTOR_SIZE,
90778a07294SKevin Wolf                                   cluster_nb_sectors * BDRV_SECTOR_SIZE,
90878a07294SKevin Wolf                                   &bounce_qiov, 0);
90961007b31SStefan Hajnoczi     }
91061007b31SStefan Hajnoczi 
91161007b31SStefan Hajnoczi     if (ret < 0) {
91261007b31SStefan Hajnoczi         /* It might be okay to ignore write errors for guest requests.  If this
91361007b31SStefan Hajnoczi          * is a deliberate copy-on-read then we don't want to ignore the error.
91461007b31SStefan Hajnoczi          * Simply report it in all cases.
91561007b31SStefan Hajnoczi          */
91661007b31SStefan Hajnoczi         goto err;
91761007b31SStefan Hajnoczi     }
91861007b31SStefan Hajnoczi 
91961007b31SStefan Hajnoczi     skip_bytes = (sector_num - cluster_sector_num) * BDRV_SECTOR_SIZE;
92061007b31SStefan Hajnoczi     qemu_iovec_from_buf(qiov, 0, bounce_buffer + skip_bytes,
92161007b31SStefan Hajnoczi                         nb_sectors * BDRV_SECTOR_SIZE);
92261007b31SStefan Hajnoczi 
92361007b31SStefan Hajnoczi err:
92461007b31SStefan Hajnoczi     qemu_vfree(bounce_buffer);
92561007b31SStefan Hajnoczi     return ret;
92661007b31SStefan Hajnoczi }
92761007b31SStefan Hajnoczi 
92861007b31SStefan Hajnoczi /*
92961007b31SStefan Hajnoczi  * Forwards an already correctly aligned request to the BlockDriver. This
93061007b31SStefan Hajnoczi  * handles copy on read and zeroing after EOF; any other features must be
93161007b31SStefan Hajnoczi  * implemented by the caller.
93261007b31SStefan Hajnoczi  */
93361007b31SStefan Hajnoczi static int coroutine_fn bdrv_aligned_preadv(BlockDriverState *bs,
93461007b31SStefan Hajnoczi     BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
93561007b31SStefan Hajnoczi     int64_t align, QEMUIOVector *qiov, int flags)
93661007b31SStefan Hajnoczi {
93761007b31SStefan Hajnoczi     int ret;
93861007b31SStefan Hajnoczi 
93961007b31SStefan Hajnoczi     int64_t sector_num = offset >> BDRV_SECTOR_BITS;
94061007b31SStefan Hajnoczi     unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
94161007b31SStefan Hajnoczi 
94261007b31SStefan Hajnoczi     assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
94361007b31SStefan Hajnoczi     assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
94461007b31SStefan Hajnoczi     assert(!qiov || bytes == qiov->size);
945abb06c5aSDaniel P. Berrange     assert((bs->open_flags & BDRV_O_NO_IO) == 0);
94661007b31SStefan Hajnoczi 
94761007b31SStefan Hajnoczi     /* Handle Copy on Read and associated serialisation */
94861007b31SStefan Hajnoczi     if (flags & BDRV_REQ_COPY_ON_READ) {
94961007b31SStefan Hajnoczi         /* If we touch the same cluster it counts as an overlap.  This
95061007b31SStefan Hajnoczi          * guarantees that allocating writes will be serialized and not race
95161007b31SStefan Hajnoczi          * with each other for the same cluster.  For example, in copy-on-read
95261007b31SStefan Hajnoczi          * it ensures that the CoR read and write operations are atomic and
95361007b31SStefan Hajnoczi          * guest writes cannot interleave between them. */
95461007b31SStefan Hajnoczi         mark_request_serialising(req, bdrv_get_cluster_size(bs));
95561007b31SStefan Hajnoczi     }
95661007b31SStefan Hajnoczi 
95761408b25SFam Zheng     if (!(flags & BDRV_REQ_NO_SERIALISING)) {
95861007b31SStefan Hajnoczi         wait_serialising_requests(req);
95961408b25SFam Zheng     }
96061007b31SStefan Hajnoczi 
96161007b31SStefan Hajnoczi     if (flags & BDRV_REQ_COPY_ON_READ) {
96261007b31SStefan Hajnoczi         int pnum;
96361007b31SStefan Hajnoczi 
96461007b31SStefan Hajnoczi         ret = bdrv_is_allocated(bs, sector_num, nb_sectors, &pnum);
96561007b31SStefan Hajnoczi         if (ret < 0) {
96661007b31SStefan Hajnoczi             goto out;
96761007b31SStefan Hajnoczi         }
96861007b31SStefan Hajnoczi 
96961007b31SStefan Hajnoczi         if (!ret || pnum != nb_sectors) {
97061007b31SStefan Hajnoczi             ret = bdrv_co_do_copy_on_readv(bs, sector_num, nb_sectors, qiov);
97161007b31SStefan Hajnoczi             goto out;
97261007b31SStefan Hajnoczi         }
97361007b31SStefan Hajnoczi     }
97461007b31SStefan Hajnoczi 
97561007b31SStefan Hajnoczi     /* Forward the request to the BlockDriver */
97661007b31SStefan Hajnoczi     if (!bs->zero_beyond_eof) {
977166fe960SKevin Wolf         ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0);
97861007b31SStefan Hajnoczi     } else {
97961007b31SStefan Hajnoczi         /* Read zeros after EOF */
98061007b31SStefan Hajnoczi         int64_t total_sectors, max_nb_sectors;
98161007b31SStefan Hajnoczi 
98261007b31SStefan Hajnoczi         total_sectors = bdrv_nb_sectors(bs);
98361007b31SStefan Hajnoczi         if (total_sectors < 0) {
98461007b31SStefan Hajnoczi             ret = total_sectors;
98561007b31SStefan Hajnoczi             goto out;
98661007b31SStefan Hajnoczi         }
98761007b31SStefan Hajnoczi 
98861007b31SStefan Hajnoczi         max_nb_sectors = ROUND_UP(MAX(0, total_sectors - sector_num),
98961007b31SStefan Hajnoczi                                   align >> BDRV_SECTOR_BITS);
99061007b31SStefan Hajnoczi         if (nb_sectors < max_nb_sectors) {
991166fe960SKevin Wolf             ret = bdrv_driver_preadv(bs, offset, bytes, qiov, 0);
99261007b31SStefan Hajnoczi         } else if (max_nb_sectors > 0) {
99361007b31SStefan Hajnoczi             QEMUIOVector local_qiov;
99461007b31SStefan Hajnoczi 
99561007b31SStefan Hajnoczi             qemu_iovec_init(&local_qiov, qiov->niov);
99661007b31SStefan Hajnoczi             qemu_iovec_concat(&local_qiov, qiov, 0,
99761007b31SStefan Hajnoczi                               max_nb_sectors * BDRV_SECTOR_SIZE);
99861007b31SStefan Hajnoczi 
999166fe960SKevin Wolf             ret = bdrv_driver_preadv(bs, offset,
1000166fe960SKevin Wolf                                      max_nb_sectors * BDRV_SECTOR_SIZE,
1001166fe960SKevin Wolf                                      &local_qiov, 0);
100261007b31SStefan Hajnoczi 
100361007b31SStefan Hajnoczi             qemu_iovec_destroy(&local_qiov);
100461007b31SStefan Hajnoczi         } else {
100561007b31SStefan Hajnoczi             ret = 0;
100661007b31SStefan Hajnoczi         }
100761007b31SStefan Hajnoczi 
100861007b31SStefan Hajnoczi         /* Reading beyond end of file is supposed to produce zeroes */
100961007b31SStefan Hajnoczi         if (ret == 0 && total_sectors < sector_num + nb_sectors) {
101061007b31SStefan Hajnoczi             uint64_t offset = MAX(0, total_sectors - sector_num);
101161007b31SStefan Hajnoczi             uint64_t bytes = (sector_num + nb_sectors - offset) *
101261007b31SStefan Hajnoczi                               BDRV_SECTOR_SIZE;
101361007b31SStefan Hajnoczi             qemu_iovec_memset(qiov, offset * BDRV_SECTOR_SIZE, 0, bytes);
101461007b31SStefan Hajnoczi         }
101561007b31SStefan Hajnoczi     }
101661007b31SStefan Hajnoczi 
101761007b31SStefan Hajnoczi out:
101861007b31SStefan Hajnoczi     return ret;
101961007b31SStefan Hajnoczi }
102061007b31SStefan Hajnoczi 
102161007b31SStefan Hajnoczi /*
102261007b31SStefan Hajnoczi  * Handle a read request in coroutine context
102361007b31SStefan Hajnoczi  */
1024cab3a356SKevin Wolf int coroutine_fn bdrv_co_preadv(BlockDriverState *bs,
102561007b31SStefan Hajnoczi     int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
102661007b31SStefan Hajnoczi     BdrvRequestFlags flags)
102761007b31SStefan Hajnoczi {
102861007b31SStefan Hajnoczi     BlockDriver *drv = bs->drv;
102961007b31SStefan Hajnoczi     BdrvTrackedRequest req;
103061007b31SStefan Hajnoczi 
1031d01c07f2SFam Zheng     /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
1032d01c07f2SFam Zheng     uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
103361007b31SStefan Hajnoczi     uint8_t *head_buf = NULL;
103461007b31SStefan Hajnoczi     uint8_t *tail_buf = NULL;
103561007b31SStefan Hajnoczi     QEMUIOVector local_qiov;
103661007b31SStefan Hajnoczi     bool use_local_qiov = false;
103761007b31SStefan Hajnoczi     int ret;
103861007b31SStefan Hajnoczi 
103961007b31SStefan Hajnoczi     if (!drv) {
104061007b31SStefan Hajnoczi         return -ENOMEDIUM;
104161007b31SStefan Hajnoczi     }
104261007b31SStefan Hajnoczi 
104361007b31SStefan Hajnoczi     ret = bdrv_check_byte_request(bs, offset, bytes);
104461007b31SStefan Hajnoczi     if (ret < 0) {
104561007b31SStefan Hajnoczi         return ret;
104661007b31SStefan Hajnoczi     }
104761007b31SStefan Hajnoczi 
10489568b511SWen Congyang     /* Don't do copy-on-read if we read data before write operation */
104961408b25SFam Zheng     if (bs->copy_on_read && !(flags & BDRV_REQ_NO_SERIALISING)) {
105061007b31SStefan Hajnoczi         flags |= BDRV_REQ_COPY_ON_READ;
105161007b31SStefan Hajnoczi     }
105261007b31SStefan Hajnoczi 
105361007b31SStefan Hajnoczi     /* Align read if necessary by padding qiov */
105461007b31SStefan Hajnoczi     if (offset & (align - 1)) {
105561007b31SStefan Hajnoczi         head_buf = qemu_blockalign(bs, align);
105661007b31SStefan Hajnoczi         qemu_iovec_init(&local_qiov, qiov->niov + 2);
105761007b31SStefan Hajnoczi         qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
105861007b31SStefan Hajnoczi         qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
105961007b31SStefan Hajnoczi         use_local_qiov = true;
106061007b31SStefan Hajnoczi 
106161007b31SStefan Hajnoczi         bytes += offset & (align - 1);
106261007b31SStefan Hajnoczi         offset = offset & ~(align - 1);
106361007b31SStefan Hajnoczi     }
106461007b31SStefan Hajnoczi 
106561007b31SStefan Hajnoczi     if ((offset + bytes) & (align - 1)) {
106661007b31SStefan Hajnoczi         if (!use_local_qiov) {
106761007b31SStefan Hajnoczi             qemu_iovec_init(&local_qiov, qiov->niov + 1);
106861007b31SStefan Hajnoczi             qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
106961007b31SStefan Hajnoczi             use_local_qiov = true;
107061007b31SStefan Hajnoczi         }
107161007b31SStefan Hajnoczi         tail_buf = qemu_blockalign(bs, align);
107261007b31SStefan Hajnoczi         qemu_iovec_add(&local_qiov, tail_buf,
107361007b31SStefan Hajnoczi                        align - ((offset + bytes) & (align - 1)));
107461007b31SStefan Hajnoczi 
107561007b31SStefan Hajnoczi         bytes = ROUND_UP(bytes, align);
107661007b31SStefan Hajnoczi     }
107761007b31SStefan Hajnoczi 
1078ebde595cSFam Zheng     tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_READ);
107961007b31SStefan Hajnoczi     ret = bdrv_aligned_preadv(bs, &req, offset, bytes, align,
108061007b31SStefan Hajnoczi                               use_local_qiov ? &local_qiov : qiov,
108161007b31SStefan Hajnoczi                               flags);
108261007b31SStefan Hajnoczi     tracked_request_end(&req);
108361007b31SStefan Hajnoczi 
108461007b31SStefan Hajnoczi     if (use_local_qiov) {
108561007b31SStefan Hajnoczi         qemu_iovec_destroy(&local_qiov);
108661007b31SStefan Hajnoczi         qemu_vfree(head_buf);
108761007b31SStefan Hajnoczi         qemu_vfree(tail_buf);
108861007b31SStefan Hajnoczi     }
108961007b31SStefan Hajnoczi 
109061007b31SStefan Hajnoczi     return ret;
109161007b31SStefan Hajnoczi }
109261007b31SStefan Hajnoczi 
109361007b31SStefan Hajnoczi static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
109461007b31SStefan Hajnoczi     int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
109561007b31SStefan Hajnoczi     BdrvRequestFlags flags)
109661007b31SStefan Hajnoczi {
109761007b31SStefan Hajnoczi     if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
109861007b31SStefan Hajnoczi         return -EINVAL;
109961007b31SStefan Hajnoczi     }
110061007b31SStefan Hajnoczi 
1101cab3a356SKevin Wolf     return bdrv_co_preadv(bs, sector_num << BDRV_SECTOR_BITS,
110261007b31SStefan Hajnoczi                           nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
110361007b31SStefan Hajnoczi }
110461007b31SStefan Hajnoczi 
110561007b31SStefan Hajnoczi int coroutine_fn bdrv_co_readv(BlockDriverState *bs, int64_t sector_num,
110661007b31SStefan Hajnoczi     int nb_sectors, QEMUIOVector *qiov)
110761007b31SStefan Hajnoczi {
110861007b31SStefan Hajnoczi     trace_bdrv_co_readv(bs, sector_num, nb_sectors);
110961007b31SStefan Hajnoczi 
111061007b31SStefan Hajnoczi     return bdrv_co_do_readv(bs, sector_num, nb_sectors, qiov, 0);
111161007b31SStefan Hajnoczi }
111261007b31SStefan Hajnoczi 
111361007b31SStefan Hajnoczi #define MAX_WRITE_ZEROES_BOUNCE_BUFFER 32768
111461007b31SStefan Hajnoczi 
1115*d05aa8bbSEric Blake static int coroutine_fn bdrv_co_do_pwrite_zeroes(BlockDriverState *bs,
1116*d05aa8bbSEric Blake     int64_t offset, int count, BdrvRequestFlags flags)
111761007b31SStefan Hajnoczi {
111861007b31SStefan Hajnoczi     BlockDriver *drv = bs->drv;
111961007b31SStefan Hajnoczi     QEMUIOVector qiov;
112061007b31SStefan Hajnoczi     struct iovec iov = {0};
112161007b31SStefan Hajnoczi     int ret = 0;
1122465fe887SEric Blake     bool need_flush = false;
1123443668caSDenis V. Lunev     int head = 0;
1124443668caSDenis V. Lunev     int tail = 0;
112561007b31SStefan Hajnoczi 
1126cf081fcaSEric Blake     int max_write_zeroes = MIN_NON_ZERO(bs->bl.max_pwrite_zeroes, INT_MAX);
1127*d05aa8bbSEric Blake     int alignment = MAX(bs->bl.pwrite_zeroes_alignment ?: 1,
1128*d05aa8bbSEric Blake                         bs->request_alignment);
1129cf081fcaSEric Blake 
1130*d05aa8bbSEric Blake     assert(is_power_of_2(alignment));
1131*d05aa8bbSEric Blake     head = offset & (alignment - 1);
1132*d05aa8bbSEric Blake     tail = (offset + count) & (alignment - 1);
1133*d05aa8bbSEric Blake     max_write_zeroes &= ~(alignment - 1);
113461007b31SStefan Hajnoczi 
1135*d05aa8bbSEric Blake     while (count > 0 && !ret) {
1136*d05aa8bbSEric Blake         int num = count;
113761007b31SStefan Hajnoczi 
113861007b31SStefan Hajnoczi         /* Align request.  Block drivers can expect the "bulk" of the request
1139443668caSDenis V. Lunev          * to be aligned, and that unaligned requests do not cross cluster
1140443668caSDenis V. Lunev          * boundaries.
114161007b31SStefan Hajnoczi          */
1142443668caSDenis V. Lunev         if (head) {
114361007b31SStefan Hajnoczi             /* Make a small request up to the first aligned sector.  */
1144*d05aa8bbSEric Blake             num = MIN(count, alignment - head);
1145443668caSDenis V. Lunev             head = 0;
1146*d05aa8bbSEric Blake         } else if (tail && num > alignment) {
1147443668caSDenis V. Lunev             /* Shorten the request to the last aligned sector.  */
1148443668caSDenis V. Lunev             num -= tail;
114961007b31SStefan Hajnoczi         }
115061007b31SStefan Hajnoczi 
115161007b31SStefan Hajnoczi         /* limit request size */
115261007b31SStefan Hajnoczi         if (num > max_write_zeroes) {
115361007b31SStefan Hajnoczi             num = max_write_zeroes;
115461007b31SStefan Hajnoczi         }
115561007b31SStefan Hajnoczi 
115661007b31SStefan Hajnoczi         ret = -ENOTSUP;
115761007b31SStefan Hajnoczi         /* First try the efficient write zeroes operation */
1158*d05aa8bbSEric Blake         if (drv->bdrv_co_pwrite_zeroes) {
1159*d05aa8bbSEric Blake             ret = drv->bdrv_co_pwrite_zeroes(bs, offset, num,
1160*d05aa8bbSEric Blake                                              flags & bs->supported_zero_flags);
1161*d05aa8bbSEric Blake             if (ret != -ENOTSUP && (flags & BDRV_REQ_FUA) &&
1162*d05aa8bbSEric Blake                 !(bs->supported_zero_flags & BDRV_REQ_FUA)) {
1163*d05aa8bbSEric Blake                 need_flush = true;
1164*d05aa8bbSEric Blake             }
1165*d05aa8bbSEric Blake         } else if (drv->bdrv_co_write_zeroes) {
1166*d05aa8bbSEric Blake             assert(offset % BDRV_SECTOR_SIZE == 0);
1167*d05aa8bbSEric Blake             assert(count % BDRV_SECTOR_SIZE == 0);
1168*d05aa8bbSEric Blake             ret = drv->bdrv_co_write_zeroes(bs, offset >> BDRV_SECTOR_BITS,
1169*d05aa8bbSEric Blake                                             num >> BDRV_SECTOR_BITS,
1170465fe887SEric Blake                                             flags & bs->supported_zero_flags);
1171465fe887SEric Blake             if (ret != -ENOTSUP && (flags & BDRV_REQ_FUA) &&
1172465fe887SEric Blake                 !(bs->supported_zero_flags & BDRV_REQ_FUA)) {
1173465fe887SEric Blake                 need_flush = true;
1174465fe887SEric Blake             }
1175465fe887SEric Blake         } else {
1176465fe887SEric Blake             assert(!bs->supported_zero_flags);
117761007b31SStefan Hajnoczi         }
117861007b31SStefan Hajnoczi 
117961007b31SStefan Hajnoczi         if (ret == -ENOTSUP) {
118061007b31SStefan Hajnoczi             /* Fall back to bounce buffer if write zeroes is unsupported */
118161007b31SStefan Hajnoczi             int max_xfer_len = MIN_NON_ZERO(bs->bl.max_transfer_length,
118261007b31SStefan Hajnoczi                                             MAX_WRITE_ZEROES_BOUNCE_BUFFER);
1183465fe887SEric Blake             BdrvRequestFlags write_flags = flags & ~BDRV_REQ_ZERO_WRITE;
1184465fe887SEric Blake 
1185465fe887SEric Blake             if ((flags & BDRV_REQ_FUA) &&
1186465fe887SEric Blake                 !(bs->supported_write_flags & BDRV_REQ_FUA)) {
1187465fe887SEric Blake                 /* No need for bdrv_driver_pwrite() to do a fallback
1188465fe887SEric Blake                  * flush on each chunk; use just one at the end */
1189465fe887SEric Blake                 write_flags &= ~BDRV_REQ_FUA;
1190465fe887SEric Blake                 need_flush = true;
1191465fe887SEric Blake             }
1192*d05aa8bbSEric Blake             num = MIN(num, max_xfer_len << BDRV_SECTOR_BITS);
1193*d05aa8bbSEric Blake             iov.iov_len = num;
119461007b31SStefan Hajnoczi             if (iov.iov_base == NULL) {
1195*d05aa8bbSEric Blake                 iov.iov_base = qemu_try_blockalign(bs, num);
119661007b31SStefan Hajnoczi                 if (iov.iov_base == NULL) {
119761007b31SStefan Hajnoczi                     ret = -ENOMEM;
119861007b31SStefan Hajnoczi                     goto fail;
119961007b31SStefan Hajnoczi                 }
1200*d05aa8bbSEric Blake                 memset(iov.iov_base, 0, num);
120161007b31SStefan Hajnoczi             }
120261007b31SStefan Hajnoczi             qemu_iovec_init_external(&qiov, &iov, 1);
120361007b31SStefan Hajnoczi 
1204*d05aa8bbSEric Blake             ret = bdrv_driver_pwritev(bs, offset, num, &qiov, write_flags);
120561007b31SStefan Hajnoczi 
120661007b31SStefan Hajnoczi             /* Keep bounce buffer around if it is big enough for all
120761007b31SStefan Hajnoczi              * all future requests.
120861007b31SStefan Hajnoczi              */
1209*d05aa8bbSEric Blake             if (num < max_xfer_len << BDRV_SECTOR_BITS) {
121061007b31SStefan Hajnoczi                 qemu_vfree(iov.iov_base);
121161007b31SStefan Hajnoczi                 iov.iov_base = NULL;
121261007b31SStefan Hajnoczi             }
121361007b31SStefan Hajnoczi         }
121461007b31SStefan Hajnoczi 
1215*d05aa8bbSEric Blake         offset += num;
1216*d05aa8bbSEric Blake         count -= num;
121761007b31SStefan Hajnoczi     }
121861007b31SStefan Hajnoczi 
121961007b31SStefan Hajnoczi fail:
1220465fe887SEric Blake     if (ret == 0 && need_flush) {
1221465fe887SEric Blake         ret = bdrv_co_flush(bs);
1222465fe887SEric Blake     }
122361007b31SStefan Hajnoczi     qemu_vfree(iov.iov_base);
122461007b31SStefan Hajnoczi     return ret;
122561007b31SStefan Hajnoczi }
122661007b31SStefan Hajnoczi 
122761007b31SStefan Hajnoczi /*
122861007b31SStefan Hajnoczi  * Forwards an already correctly aligned write request to the BlockDriver.
122961007b31SStefan Hajnoczi  */
123061007b31SStefan Hajnoczi static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
123161007b31SStefan Hajnoczi     BdrvTrackedRequest *req, int64_t offset, unsigned int bytes,
123261007b31SStefan Hajnoczi     QEMUIOVector *qiov, int flags)
123361007b31SStefan Hajnoczi {
123461007b31SStefan Hajnoczi     BlockDriver *drv = bs->drv;
123561007b31SStefan Hajnoczi     bool waited;
123661007b31SStefan Hajnoczi     int ret;
123761007b31SStefan Hajnoczi 
123861007b31SStefan Hajnoczi     int64_t sector_num = offset >> BDRV_SECTOR_BITS;
123961007b31SStefan Hajnoczi     unsigned int nb_sectors = bytes >> BDRV_SECTOR_BITS;
124061007b31SStefan Hajnoczi 
124161007b31SStefan Hajnoczi     assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
124261007b31SStefan Hajnoczi     assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
124361007b31SStefan Hajnoczi     assert(!qiov || bytes == qiov->size);
1244abb06c5aSDaniel P. Berrange     assert((bs->open_flags & BDRV_O_NO_IO) == 0);
124561007b31SStefan Hajnoczi 
124661007b31SStefan Hajnoczi     waited = wait_serialising_requests(req);
124761007b31SStefan Hajnoczi     assert(!waited || !req->serialising);
124861007b31SStefan Hajnoczi     assert(req->overlap_offset <= offset);
124961007b31SStefan Hajnoczi     assert(offset + bytes <= req->overlap_offset + req->overlap_bytes);
125061007b31SStefan Hajnoczi 
125161007b31SStefan Hajnoczi     ret = notifier_with_return_list_notify(&bs->before_write_notifiers, req);
125261007b31SStefan Hajnoczi 
125361007b31SStefan Hajnoczi     if (!ret && bs->detect_zeroes != BLOCKDEV_DETECT_ZEROES_OPTIONS_OFF &&
1254*d05aa8bbSEric Blake         !(flags & BDRV_REQ_ZERO_WRITE) &&
1255*d05aa8bbSEric Blake         (drv->bdrv_co_pwrite_zeroes || drv->bdrv_co_write_zeroes) &&
125661007b31SStefan Hajnoczi         qemu_iovec_is_zero(qiov)) {
125761007b31SStefan Hajnoczi         flags |= BDRV_REQ_ZERO_WRITE;
125861007b31SStefan Hajnoczi         if (bs->detect_zeroes == BLOCKDEV_DETECT_ZEROES_OPTIONS_UNMAP) {
125961007b31SStefan Hajnoczi             flags |= BDRV_REQ_MAY_UNMAP;
126061007b31SStefan Hajnoczi         }
126161007b31SStefan Hajnoczi     }
126261007b31SStefan Hajnoczi 
126361007b31SStefan Hajnoczi     if (ret < 0) {
126461007b31SStefan Hajnoczi         /* Do nothing, write notifier decided to fail this request */
126561007b31SStefan Hajnoczi     } else if (flags & BDRV_REQ_ZERO_WRITE) {
12669a4f4c31SKevin Wolf         bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO);
1267*d05aa8bbSEric Blake         ret = bdrv_co_do_pwrite_zeroes(bs, sector_num << BDRV_SECTOR_BITS,
1268*d05aa8bbSEric Blake                                        nb_sectors << BDRV_SECTOR_BITS, flags);
126961007b31SStefan Hajnoczi     } else {
12709a4f4c31SKevin Wolf         bdrv_debug_event(bs, BLKDBG_PWRITEV);
127178a07294SKevin Wolf         ret = bdrv_driver_pwritev(bs, offset, bytes, qiov, flags);
127261007b31SStefan Hajnoczi     }
12739a4f4c31SKevin Wolf     bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE);
127461007b31SStefan Hajnoczi 
127561007b31SStefan Hajnoczi     bdrv_set_dirty(bs, sector_num, nb_sectors);
127661007b31SStefan Hajnoczi 
127753d8f9d8SMax Reitz     if (bs->wr_highest_offset < offset + bytes) {
127853d8f9d8SMax Reitz         bs->wr_highest_offset = offset + bytes;
127953d8f9d8SMax Reitz     }
128061007b31SStefan Hajnoczi 
128161007b31SStefan Hajnoczi     if (ret >= 0) {
128261007b31SStefan Hajnoczi         bs->total_sectors = MAX(bs->total_sectors, sector_num + nb_sectors);
128361007b31SStefan Hajnoczi     }
128461007b31SStefan Hajnoczi 
128561007b31SStefan Hajnoczi     return ret;
128661007b31SStefan Hajnoczi }
128761007b31SStefan Hajnoczi 
12889eeb6dd1SFam Zheng static int coroutine_fn bdrv_co_do_zero_pwritev(BlockDriverState *bs,
12899eeb6dd1SFam Zheng                                                 int64_t offset,
12909eeb6dd1SFam Zheng                                                 unsigned int bytes,
12919eeb6dd1SFam Zheng                                                 BdrvRequestFlags flags,
12929eeb6dd1SFam Zheng                                                 BdrvTrackedRequest *req)
12939eeb6dd1SFam Zheng {
12949eeb6dd1SFam Zheng     uint8_t *buf = NULL;
12959eeb6dd1SFam Zheng     QEMUIOVector local_qiov;
12969eeb6dd1SFam Zheng     struct iovec iov;
12979eeb6dd1SFam Zheng     uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
12989eeb6dd1SFam Zheng     unsigned int head_padding_bytes, tail_padding_bytes;
12999eeb6dd1SFam Zheng     int ret = 0;
13009eeb6dd1SFam Zheng 
13019eeb6dd1SFam Zheng     head_padding_bytes = offset & (align - 1);
13029eeb6dd1SFam Zheng     tail_padding_bytes = align - ((offset + bytes) & (align - 1));
13039eeb6dd1SFam Zheng 
13049eeb6dd1SFam Zheng 
13059eeb6dd1SFam Zheng     assert(flags & BDRV_REQ_ZERO_WRITE);
13069eeb6dd1SFam Zheng     if (head_padding_bytes || tail_padding_bytes) {
13079eeb6dd1SFam Zheng         buf = qemu_blockalign(bs, align);
13089eeb6dd1SFam Zheng         iov = (struct iovec) {
13099eeb6dd1SFam Zheng             .iov_base   = buf,
13109eeb6dd1SFam Zheng             .iov_len    = align,
13119eeb6dd1SFam Zheng         };
13129eeb6dd1SFam Zheng         qemu_iovec_init_external(&local_qiov, &iov, 1);
13139eeb6dd1SFam Zheng     }
13149eeb6dd1SFam Zheng     if (head_padding_bytes) {
13159eeb6dd1SFam Zheng         uint64_t zero_bytes = MIN(bytes, align - head_padding_bytes);
13169eeb6dd1SFam Zheng 
13179eeb6dd1SFam Zheng         /* RMW the unaligned part before head. */
13189eeb6dd1SFam Zheng         mark_request_serialising(req, align);
13199eeb6dd1SFam Zheng         wait_serialising_requests(req);
13209a4f4c31SKevin Wolf         bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD);
13219eeb6dd1SFam Zheng         ret = bdrv_aligned_preadv(bs, req, offset & ~(align - 1), align,
13229eeb6dd1SFam Zheng                                   align, &local_qiov, 0);
13239eeb6dd1SFam Zheng         if (ret < 0) {
13249eeb6dd1SFam Zheng             goto fail;
13259eeb6dd1SFam Zheng         }
13269a4f4c31SKevin Wolf         bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
13279eeb6dd1SFam Zheng 
13289eeb6dd1SFam Zheng         memset(buf + head_padding_bytes, 0, zero_bytes);
13299eeb6dd1SFam Zheng         ret = bdrv_aligned_pwritev(bs, req, offset & ~(align - 1), align,
13309eeb6dd1SFam Zheng                                    &local_qiov,
13319eeb6dd1SFam Zheng                                    flags & ~BDRV_REQ_ZERO_WRITE);
13329eeb6dd1SFam Zheng         if (ret < 0) {
13339eeb6dd1SFam Zheng             goto fail;
13349eeb6dd1SFam Zheng         }
13359eeb6dd1SFam Zheng         offset += zero_bytes;
13369eeb6dd1SFam Zheng         bytes -= zero_bytes;
13379eeb6dd1SFam Zheng     }
13389eeb6dd1SFam Zheng 
13399eeb6dd1SFam Zheng     assert(!bytes || (offset & (align - 1)) == 0);
13409eeb6dd1SFam Zheng     if (bytes >= align) {
13419eeb6dd1SFam Zheng         /* Write the aligned part in the middle. */
13429eeb6dd1SFam Zheng         uint64_t aligned_bytes = bytes & ~(align - 1);
13439eeb6dd1SFam Zheng         ret = bdrv_aligned_pwritev(bs, req, offset, aligned_bytes,
13449eeb6dd1SFam Zheng                                    NULL, flags);
13459eeb6dd1SFam Zheng         if (ret < 0) {
13469eeb6dd1SFam Zheng             goto fail;
13479eeb6dd1SFam Zheng         }
13489eeb6dd1SFam Zheng         bytes -= aligned_bytes;
13499eeb6dd1SFam Zheng         offset += aligned_bytes;
13509eeb6dd1SFam Zheng     }
13519eeb6dd1SFam Zheng 
13529eeb6dd1SFam Zheng     assert(!bytes || (offset & (align - 1)) == 0);
13539eeb6dd1SFam Zheng     if (bytes) {
13549eeb6dd1SFam Zheng         assert(align == tail_padding_bytes + bytes);
13559eeb6dd1SFam Zheng         /* RMW the unaligned part after tail. */
13569eeb6dd1SFam Zheng         mark_request_serialising(req, align);
13579eeb6dd1SFam Zheng         wait_serialising_requests(req);
13589a4f4c31SKevin Wolf         bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
13599eeb6dd1SFam Zheng         ret = bdrv_aligned_preadv(bs, req, offset, align,
13609eeb6dd1SFam Zheng                                   align, &local_qiov, 0);
13619eeb6dd1SFam Zheng         if (ret < 0) {
13629eeb6dd1SFam Zheng             goto fail;
13639eeb6dd1SFam Zheng         }
13649a4f4c31SKevin Wolf         bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
13659eeb6dd1SFam Zheng 
13669eeb6dd1SFam Zheng         memset(buf, 0, bytes);
13679eeb6dd1SFam Zheng         ret = bdrv_aligned_pwritev(bs, req, offset, align,
13689eeb6dd1SFam Zheng                                    &local_qiov, flags & ~BDRV_REQ_ZERO_WRITE);
13699eeb6dd1SFam Zheng     }
13709eeb6dd1SFam Zheng fail:
13719eeb6dd1SFam Zheng     qemu_vfree(buf);
13729eeb6dd1SFam Zheng     return ret;
13739eeb6dd1SFam Zheng 
13749eeb6dd1SFam Zheng }
13759eeb6dd1SFam Zheng 
137661007b31SStefan Hajnoczi /*
137761007b31SStefan Hajnoczi  * Handle a write request in coroutine context
137861007b31SStefan Hajnoczi  */
1379cab3a356SKevin Wolf int coroutine_fn bdrv_co_pwritev(BlockDriverState *bs,
138061007b31SStefan Hajnoczi     int64_t offset, unsigned int bytes, QEMUIOVector *qiov,
138161007b31SStefan Hajnoczi     BdrvRequestFlags flags)
138261007b31SStefan Hajnoczi {
138361007b31SStefan Hajnoczi     BdrvTrackedRequest req;
1384d01c07f2SFam Zheng     /* TODO Lift BDRV_SECTOR_SIZE restriction in BlockDriver interface */
1385d01c07f2SFam Zheng     uint64_t align = MAX(BDRV_SECTOR_SIZE, bs->request_alignment);
138661007b31SStefan Hajnoczi     uint8_t *head_buf = NULL;
138761007b31SStefan Hajnoczi     uint8_t *tail_buf = NULL;
138861007b31SStefan Hajnoczi     QEMUIOVector local_qiov;
138961007b31SStefan Hajnoczi     bool use_local_qiov = false;
139061007b31SStefan Hajnoczi     int ret;
139161007b31SStefan Hajnoczi 
139261007b31SStefan Hajnoczi     if (!bs->drv) {
139361007b31SStefan Hajnoczi         return -ENOMEDIUM;
139461007b31SStefan Hajnoczi     }
139561007b31SStefan Hajnoczi     if (bs->read_only) {
1396eaf5fe2dSPaolo Bonzini         return -EPERM;
139761007b31SStefan Hajnoczi     }
139804c01a5cSKevin Wolf     assert(!(bs->open_flags & BDRV_O_INACTIVE));
139961007b31SStefan Hajnoczi 
140061007b31SStefan Hajnoczi     ret = bdrv_check_byte_request(bs, offset, bytes);
140161007b31SStefan Hajnoczi     if (ret < 0) {
140261007b31SStefan Hajnoczi         return ret;
140361007b31SStefan Hajnoczi     }
140461007b31SStefan Hajnoczi 
140561007b31SStefan Hajnoczi     /*
140661007b31SStefan Hajnoczi      * Align write if necessary by performing a read-modify-write cycle.
140761007b31SStefan Hajnoczi      * Pad qiov with the read parts and be sure to have a tracked request not
140861007b31SStefan Hajnoczi      * only for bdrv_aligned_pwritev, but also for the reads of the RMW cycle.
140961007b31SStefan Hajnoczi      */
1410ebde595cSFam Zheng     tracked_request_begin(&req, bs, offset, bytes, BDRV_TRACKED_WRITE);
141161007b31SStefan Hajnoczi 
14129eeb6dd1SFam Zheng     if (!qiov) {
14139eeb6dd1SFam Zheng         ret = bdrv_co_do_zero_pwritev(bs, offset, bytes, flags, &req);
14149eeb6dd1SFam Zheng         goto out;
14159eeb6dd1SFam Zheng     }
14169eeb6dd1SFam Zheng 
141761007b31SStefan Hajnoczi     if (offset & (align - 1)) {
141861007b31SStefan Hajnoczi         QEMUIOVector head_qiov;
141961007b31SStefan Hajnoczi         struct iovec head_iov;
142061007b31SStefan Hajnoczi 
142161007b31SStefan Hajnoczi         mark_request_serialising(&req, align);
142261007b31SStefan Hajnoczi         wait_serialising_requests(&req);
142361007b31SStefan Hajnoczi 
142461007b31SStefan Hajnoczi         head_buf = qemu_blockalign(bs, align);
142561007b31SStefan Hajnoczi         head_iov = (struct iovec) {
142661007b31SStefan Hajnoczi             .iov_base   = head_buf,
142761007b31SStefan Hajnoczi             .iov_len    = align,
142861007b31SStefan Hajnoczi         };
142961007b31SStefan Hajnoczi         qemu_iovec_init_external(&head_qiov, &head_iov, 1);
143061007b31SStefan Hajnoczi 
14319a4f4c31SKevin Wolf         bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_HEAD);
143261007b31SStefan Hajnoczi         ret = bdrv_aligned_preadv(bs, &req, offset & ~(align - 1), align,
143361007b31SStefan Hajnoczi                                   align, &head_qiov, 0);
143461007b31SStefan Hajnoczi         if (ret < 0) {
143561007b31SStefan Hajnoczi             goto fail;
143661007b31SStefan Hajnoczi         }
14379a4f4c31SKevin Wolf         bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_HEAD);
143861007b31SStefan Hajnoczi 
143961007b31SStefan Hajnoczi         qemu_iovec_init(&local_qiov, qiov->niov + 2);
144061007b31SStefan Hajnoczi         qemu_iovec_add(&local_qiov, head_buf, offset & (align - 1));
144161007b31SStefan Hajnoczi         qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
144261007b31SStefan Hajnoczi         use_local_qiov = true;
144361007b31SStefan Hajnoczi 
144461007b31SStefan Hajnoczi         bytes += offset & (align - 1);
144561007b31SStefan Hajnoczi         offset = offset & ~(align - 1);
1446117bc3faSPeter Lieven 
1447117bc3faSPeter Lieven         /* We have read the tail already if the request is smaller
1448117bc3faSPeter Lieven          * than one aligned block.
1449117bc3faSPeter Lieven          */
1450117bc3faSPeter Lieven         if (bytes < align) {
1451117bc3faSPeter Lieven             qemu_iovec_add(&local_qiov, head_buf + bytes, align - bytes);
1452117bc3faSPeter Lieven             bytes = align;
1453117bc3faSPeter Lieven         }
145461007b31SStefan Hajnoczi     }
145561007b31SStefan Hajnoczi 
145661007b31SStefan Hajnoczi     if ((offset + bytes) & (align - 1)) {
145761007b31SStefan Hajnoczi         QEMUIOVector tail_qiov;
145861007b31SStefan Hajnoczi         struct iovec tail_iov;
145961007b31SStefan Hajnoczi         size_t tail_bytes;
146061007b31SStefan Hajnoczi         bool waited;
146161007b31SStefan Hajnoczi 
146261007b31SStefan Hajnoczi         mark_request_serialising(&req, align);
146361007b31SStefan Hajnoczi         waited = wait_serialising_requests(&req);
146461007b31SStefan Hajnoczi         assert(!waited || !use_local_qiov);
146561007b31SStefan Hajnoczi 
146661007b31SStefan Hajnoczi         tail_buf = qemu_blockalign(bs, align);
146761007b31SStefan Hajnoczi         tail_iov = (struct iovec) {
146861007b31SStefan Hajnoczi             .iov_base   = tail_buf,
146961007b31SStefan Hajnoczi             .iov_len    = align,
147061007b31SStefan Hajnoczi         };
147161007b31SStefan Hajnoczi         qemu_iovec_init_external(&tail_qiov, &tail_iov, 1);
147261007b31SStefan Hajnoczi 
14739a4f4c31SKevin Wolf         bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_TAIL);
147461007b31SStefan Hajnoczi         ret = bdrv_aligned_preadv(bs, &req, (offset + bytes) & ~(align - 1), align,
147561007b31SStefan Hajnoczi                                   align, &tail_qiov, 0);
147661007b31SStefan Hajnoczi         if (ret < 0) {
147761007b31SStefan Hajnoczi             goto fail;
147861007b31SStefan Hajnoczi         }
14799a4f4c31SKevin Wolf         bdrv_debug_event(bs, BLKDBG_PWRITEV_RMW_AFTER_TAIL);
148061007b31SStefan Hajnoczi 
148161007b31SStefan Hajnoczi         if (!use_local_qiov) {
148261007b31SStefan Hajnoczi             qemu_iovec_init(&local_qiov, qiov->niov + 1);
148361007b31SStefan Hajnoczi             qemu_iovec_concat(&local_qiov, qiov, 0, qiov->size);
148461007b31SStefan Hajnoczi             use_local_qiov = true;
148561007b31SStefan Hajnoczi         }
148661007b31SStefan Hajnoczi 
148761007b31SStefan Hajnoczi         tail_bytes = (offset + bytes) & (align - 1);
148861007b31SStefan Hajnoczi         qemu_iovec_add(&local_qiov, tail_buf + tail_bytes, align - tail_bytes);
148961007b31SStefan Hajnoczi 
149061007b31SStefan Hajnoczi         bytes = ROUND_UP(bytes, align);
149161007b31SStefan Hajnoczi     }
149261007b31SStefan Hajnoczi 
149361007b31SStefan Hajnoczi     ret = bdrv_aligned_pwritev(bs, &req, offset, bytes,
149461007b31SStefan Hajnoczi                                use_local_qiov ? &local_qiov : qiov,
149561007b31SStefan Hajnoczi                                flags);
149661007b31SStefan Hajnoczi 
149761007b31SStefan Hajnoczi fail:
149861007b31SStefan Hajnoczi 
149961007b31SStefan Hajnoczi     if (use_local_qiov) {
150061007b31SStefan Hajnoczi         qemu_iovec_destroy(&local_qiov);
150161007b31SStefan Hajnoczi     }
150261007b31SStefan Hajnoczi     qemu_vfree(head_buf);
150361007b31SStefan Hajnoczi     qemu_vfree(tail_buf);
15049eeb6dd1SFam Zheng out:
15059eeb6dd1SFam Zheng     tracked_request_end(&req);
150661007b31SStefan Hajnoczi     return ret;
150761007b31SStefan Hajnoczi }
150861007b31SStefan Hajnoczi 
150961007b31SStefan Hajnoczi static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
151061007b31SStefan Hajnoczi     int64_t sector_num, int nb_sectors, QEMUIOVector *qiov,
151161007b31SStefan Hajnoczi     BdrvRequestFlags flags)
151261007b31SStefan Hajnoczi {
151361007b31SStefan Hajnoczi     if (nb_sectors < 0 || nb_sectors > BDRV_REQUEST_MAX_SECTORS) {
151461007b31SStefan Hajnoczi         return -EINVAL;
151561007b31SStefan Hajnoczi     }
151661007b31SStefan Hajnoczi 
1517cab3a356SKevin Wolf     return bdrv_co_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
151861007b31SStefan Hajnoczi                            nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
151961007b31SStefan Hajnoczi }
152061007b31SStefan Hajnoczi 
152161007b31SStefan Hajnoczi int coroutine_fn bdrv_co_writev(BlockDriverState *bs, int64_t sector_num,
152261007b31SStefan Hajnoczi     int nb_sectors, QEMUIOVector *qiov)
152361007b31SStefan Hajnoczi {
152461007b31SStefan Hajnoczi     trace_bdrv_co_writev(bs, sector_num, nb_sectors);
152561007b31SStefan Hajnoczi 
152661007b31SStefan Hajnoczi     return bdrv_co_do_writev(bs, sector_num, nb_sectors, qiov, 0);
152761007b31SStefan Hajnoczi }
152861007b31SStefan Hajnoczi 
152961007b31SStefan Hajnoczi int coroutine_fn bdrv_co_write_zeroes(BlockDriverState *bs,
153061007b31SStefan Hajnoczi                                       int64_t sector_num, int nb_sectors,
153161007b31SStefan Hajnoczi                                       BdrvRequestFlags flags)
153261007b31SStefan Hajnoczi {
153361007b31SStefan Hajnoczi     trace_bdrv_co_write_zeroes(bs, sector_num, nb_sectors, flags);
153461007b31SStefan Hajnoczi 
153561007b31SStefan Hajnoczi     if (!(bs->open_flags & BDRV_O_UNMAP)) {
153661007b31SStefan Hajnoczi         flags &= ~BDRV_REQ_MAY_UNMAP;
153761007b31SStefan Hajnoczi     }
153861007b31SStefan Hajnoczi 
1539d01c07f2SFam Zheng     return bdrv_co_do_writev(bs, sector_num, nb_sectors, NULL,
154061007b31SStefan Hajnoczi                              BDRV_REQ_ZERO_WRITE | flags);
154161007b31SStefan Hajnoczi }
154261007b31SStefan Hajnoczi 
154361007b31SStefan Hajnoczi typedef struct BdrvCoGetBlockStatusData {
154461007b31SStefan Hajnoczi     BlockDriverState *bs;
154561007b31SStefan Hajnoczi     BlockDriverState *base;
154667a0fd2aSFam Zheng     BlockDriverState **file;
154761007b31SStefan Hajnoczi     int64_t sector_num;
154861007b31SStefan Hajnoczi     int nb_sectors;
154961007b31SStefan Hajnoczi     int *pnum;
155061007b31SStefan Hajnoczi     int64_t ret;
155161007b31SStefan Hajnoczi     bool done;
155261007b31SStefan Hajnoczi } BdrvCoGetBlockStatusData;
155361007b31SStefan Hajnoczi 
155461007b31SStefan Hajnoczi /*
155561007b31SStefan Hajnoczi  * Returns the allocation status of the specified sectors.
155661007b31SStefan Hajnoczi  * Drivers not implementing the functionality are assumed to not support
155761007b31SStefan Hajnoczi  * backing files, hence all their sectors are reported as allocated.
155861007b31SStefan Hajnoczi  *
155961007b31SStefan Hajnoczi  * If 'sector_num' is beyond the end of the disk image the return value is 0
156061007b31SStefan Hajnoczi  * and 'pnum' is set to 0.
156161007b31SStefan Hajnoczi  *
156261007b31SStefan Hajnoczi  * 'pnum' is set to the number of sectors (including and immediately following
156361007b31SStefan Hajnoczi  * the specified sector) that are known to be in the same
156461007b31SStefan Hajnoczi  * allocated/unallocated state.
156561007b31SStefan Hajnoczi  *
156661007b31SStefan Hajnoczi  * 'nb_sectors' is the max value 'pnum' should be set to.  If nb_sectors goes
156761007b31SStefan Hajnoczi  * beyond the end of the disk image it will be clamped.
156867a0fd2aSFam Zheng  *
156967a0fd2aSFam Zheng  * If returned value is positive and BDRV_BLOCK_OFFSET_VALID bit is set, 'file'
157067a0fd2aSFam Zheng  * points to the BDS which the sector range is allocated in.
157161007b31SStefan Hajnoczi  */
157261007b31SStefan Hajnoczi static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs,
157361007b31SStefan Hajnoczi                                                      int64_t sector_num,
157467a0fd2aSFam Zheng                                                      int nb_sectors, int *pnum,
157567a0fd2aSFam Zheng                                                      BlockDriverState **file)
157661007b31SStefan Hajnoczi {
157761007b31SStefan Hajnoczi     int64_t total_sectors;
157861007b31SStefan Hajnoczi     int64_t n;
157961007b31SStefan Hajnoczi     int64_t ret, ret2;
158061007b31SStefan Hajnoczi 
158161007b31SStefan Hajnoczi     total_sectors = bdrv_nb_sectors(bs);
158261007b31SStefan Hajnoczi     if (total_sectors < 0) {
158361007b31SStefan Hajnoczi         return total_sectors;
158461007b31SStefan Hajnoczi     }
158561007b31SStefan Hajnoczi 
158661007b31SStefan Hajnoczi     if (sector_num >= total_sectors) {
158761007b31SStefan Hajnoczi         *pnum = 0;
158861007b31SStefan Hajnoczi         return 0;
158961007b31SStefan Hajnoczi     }
159061007b31SStefan Hajnoczi 
159161007b31SStefan Hajnoczi     n = total_sectors - sector_num;
159261007b31SStefan Hajnoczi     if (n < nb_sectors) {
159361007b31SStefan Hajnoczi         nb_sectors = n;
159461007b31SStefan Hajnoczi     }
159561007b31SStefan Hajnoczi 
159661007b31SStefan Hajnoczi     if (!bs->drv->bdrv_co_get_block_status) {
159761007b31SStefan Hajnoczi         *pnum = nb_sectors;
159861007b31SStefan Hajnoczi         ret = BDRV_BLOCK_DATA | BDRV_BLOCK_ALLOCATED;
159961007b31SStefan Hajnoczi         if (bs->drv->protocol_name) {
160061007b31SStefan Hajnoczi             ret |= BDRV_BLOCK_OFFSET_VALID | (sector_num * BDRV_SECTOR_SIZE);
160161007b31SStefan Hajnoczi         }
160261007b31SStefan Hajnoczi         return ret;
160361007b31SStefan Hajnoczi     }
160461007b31SStefan Hajnoczi 
160567a0fd2aSFam Zheng     *file = NULL;
160667a0fd2aSFam Zheng     ret = bs->drv->bdrv_co_get_block_status(bs, sector_num, nb_sectors, pnum,
160767a0fd2aSFam Zheng                                             file);
160861007b31SStefan Hajnoczi     if (ret < 0) {
160961007b31SStefan Hajnoczi         *pnum = 0;
161061007b31SStefan Hajnoczi         return ret;
161161007b31SStefan Hajnoczi     }
161261007b31SStefan Hajnoczi 
161361007b31SStefan Hajnoczi     if (ret & BDRV_BLOCK_RAW) {
161461007b31SStefan Hajnoczi         assert(ret & BDRV_BLOCK_OFFSET_VALID);
16159a4f4c31SKevin Wolf         return bdrv_get_block_status(bs->file->bs, ret >> BDRV_SECTOR_BITS,
161667a0fd2aSFam Zheng                                      *pnum, pnum, file);
161761007b31SStefan Hajnoczi     }
161861007b31SStefan Hajnoczi 
161961007b31SStefan Hajnoczi     if (ret & (BDRV_BLOCK_DATA | BDRV_BLOCK_ZERO)) {
162061007b31SStefan Hajnoczi         ret |= BDRV_BLOCK_ALLOCATED;
1621a53f1a95SPaolo Bonzini     } else {
162261007b31SStefan Hajnoczi         if (bdrv_unallocated_blocks_are_zero(bs)) {
162361007b31SStefan Hajnoczi             ret |= BDRV_BLOCK_ZERO;
1624760e0063SKevin Wolf         } else if (bs->backing) {
1625760e0063SKevin Wolf             BlockDriverState *bs2 = bs->backing->bs;
162661007b31SStefan Hajnoczi             int64_t nb_sectors2 = bdrv_nb_sectors(bs2);
162761007b31SStefan Hajnoczi             if (nb_sectors2 >= 0 && sector_num >= nb_sectors2) {
162861007b31SStefan Hajnoczi                 ret |= BDRV_BLOCK_ZERO;
162961007b31SStefan Hajnoczi             }
163061007b31SStefan Hajnoczi         }
163161007b31SStefan Hajnoczi     }
163261007b31SStefan Hajnoczi 
1633ac987b30SFam Zheng     if (*file && *file != bs &&
163461007b31SStefan Hajnoczi         (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) &&
163561007b31SStefan Hajnoczi         (ret & BDRV_BLOCK_OFFSET_VALID)) {
163667a0fd2aSFam Zheng         BlockDriverState *file2;
163761007b31SStefan Hajnoczi         int file_pnum;
163861007b31SStefan Hajnoczi 
1639ac987b30SFam Zheng         ret2 = bdrv_co_get_block_status(*file, ret >> BDRV_SECTOR_BITS,
164067a0fd2aSFam Zheng                                         *pnum, &file_pnum, &file2);
164161007b31SStefan Hajnoczi         if (ret2 >= 0) {
164261007b31SStefan Hajnoczi             /* Ignore errors.  This is just providing extra information, it
164361007b31SStefan Hajnoczi              * is useful but not necessary.
164461007b31SStefan Hajnoczi              */
164561007b31SStefan Hajnoczi             if (!file_pnum) {
164661007b31SStefan Hajnoczi                 /* !file_pnum indicates an offset at or beyond the EOF; it is
164761007b31SStefan Hajnoczi                  * perfectly valid for the format block driver to point to such
164861007b31SStefan Hajnoczi                  * offsets, so catch it and mark everything as zero */
164961007b31SStefan Hajnoczi                 ret |= BDRV_BLOCK_ZERO;
165061007b31SStefan Hajnoczi             } else {
165161007b31SStefan Hajnoczi                 /* Limit request to the range reported by the protocol driver */
165261007b31SStefan Hajnoczi                 *pnum = file_pnum;
165361007b31SStefan Hajnoczi                 ret |= (ret2 & BDRV_BLOCK_ZERO);
165461007b31SStefan Hajnoczi             }
165561007b31SStefan Hajnoczi         }
165661007b31SStefan Hajnoczi     }
165761007b31SStefan Hajnoczi 
165861007b31SStefan Hajnoczi     return ret;
165961007b31SStefan Hajnoczi }
166061007b31SStefan Hajnoczi 
1661ba3f0e25SFam Zheng static int64_t coroutine_fn bdrv_co_get_block_status_above(BlockDriverState *bs,
1662ba3f0e25SFam Zheng         BlockDriverState *base,
1663ba3f0e25SFam Zheng         int64_t sector_num,
1664ba3f0e25SFam Zheng         int nb_sectors,
166567a0fd2aSFam Zheng         int *pnum,
166667a0fd2aSFam Zheng         BlockDriverState **file)
1667ba3f0e25SFam Zheng {
1668ba3f0e25SFam Zheng     BlockDriverState *p;
1669ba3f0e25SFam Zheng     int64_t ret = 0;
1670ba3f0e25SFam Zheng 
1671ba3f0e25SFam Zheng     assert(bs != base);
1672760e0063SKevin Wolf     for (p = bs; p != base; p = backing_bs(p)) {
167367a0fd2aSFam Zheng         ret = bdrv_co_get_block_status(p, sector_num, nb_sectors, pnum, file);
1674ba3f0e25SFam Zheng         if (ret < 0 || ret & BDRV_BLOCK_ALLOCATED) {
1675ba3f0e25SFam Zheng             break;
1676ba3f0e25SFam Zheng         }
1677ba3f0e25SFam Zheng         /* [sector_num, pnum] unallocated on this layer, which could be only
1678ba3f0e25SFam Zheng          * the first part of [sector_num, nb_sectors].  */
1679ba3f0e25SFam Zheng         nb_sectors = MIN(nb_sectors, *pnum);
1680ba3f0e25SFam Zheng     }
1681ba3f0e25SFam Zheng     return ret;
1682ba3f0e25SFam Zheng }
1683ba3f0e25SFam Zheng 
1684ba3f0e25SFam Zheng /* Coroutine wrapper for bdrv_get_block_status_above() */
1685ba3f0e25SFam Zheng static void coroutine_fn bdrv_get_block_status_above_co_entry(void *opaque)
168661007b31SStefan Hajnoczi {
168761007b31SStefan Hajnoczi     BdrvCoGetBlockStatusData *data = opaque;
168861007b31SStefan Hajnoczi 
1689ba3f0e25SFam Zheng     data->ret = bdrv_co_get_block_status_above(data->bs, data->base,
1690ba3f0e25SFam Zheng                                                data->sector_num,
1691ba3f0e25SFam Zheng                                                data->nb_sectors,
169267a0fd2aSFam Zheng                                                data->pnum,
169367a0fd2aSFam Zheng                                                data->file);
169461007b31SStefan Hajnoczi     data->done = true;
169561007b31SStefan Hajnoczi }
169661007b31SStefan Hajnoczi 
169761007b31SStefan Hajnoczi /*
1698ba3f0e25SFam Zheng  * Synchronous wrapper around bdrv_co_get_block_status_above().
169961007b31SStefan Hajnoczi  *
1700ba3f0e25SFam Zheng  * See bdrv_co_get_block_status_above() for details.
170161007b31SStefan Hajnoczi  */
1702ba3f0e25SFam Zheng int64_t bdrv_get_block_status_above(BlockDriverState *bs,
1703ba3f0e25SFam Zheng                                     BlockDriverState *base,
1704ba3f0e25SFam Zheng                                     int64_t sector_num,
170567a0fd2aSFam Zheng                                     int nb_sectors, int *pnum,
170667a0fd2aSFam Zheng                                     BlockDriverState **file)
170761007b31SStefan Hajnoczi {
170861007b31SStefan Hajnoczi     Coroutine *co;
170961007b31SStefan Hajnoczi     BdrvCoGetBlockStatusData data = {
171061007b31SStefan Hajnoczi         .bs = bs,
1711ba3f0e25SFam Zheng         .base = base,
171267a0fd2aSFam Zheng         .file = file,
171361007b31SStefan Hajnoczi         .sector_num = sector_num,
171461007b31SStefan Hajnoczi         .nb_sectors = nb_sectors,
171561007b31SStefan Hajnoczi         .pnum = pnum,
171661007b31SStefan Hajnoczi         .done = false,
171761007b31SStefan Hajnoczi     };
171861007b31SStefan Hajnoczi 
171961007b31SStefan Hajnoczi     if (qemu_in_coroutine()) {
172061007b31SStefan Hajnoczi         /* Fast-path if already in coroutine context */
1721ba3f0e25SFam Zheng         bdrv_get_block_status_above_co_entry(&data);
172261007b31SStefan Hajnoczi     } else {
172361007b31SStefan Hajnoczi         AioContext *aio_context = bdrv_get_aio_context(bs);
172461007b31SStefan Hajnoczi 
1725ba3f0e25SFam Zheng         co = qemu_coroutine_create(bdrv_get_block_status_above_co_entry);
172661007b31SStefan Hajnoczi         qemu_coroutine_enter(co, &data);
172761007b31SStefan Hajnoczi         while (!data.done) {
172861007b31SStefan Hajnoczi             aio_poll(aio_context, true);
172961007b31SStefan Hajnoczi         }
173061007b31SStefan Hajnoczi     }
173161007b31SStefan Hajnoczi     return data.ret;
173261007b31SStefan Hajnoczi }
173361007b31SStefan Hajnoczi 
1734ba3f0e25SFam Zheng int64_t bdrv_get_block_status(BlockDriverState *bs,
1735ba3f0e25SFam Zheng                               int64_t sector_num,
173667a0fd2aSFam Zheng                               int nb_sectors, int *pnum,
173767a0fd2aSFam Zheng                               BlockDriverState **file)
1738ba3f0e25SFam Zheng {
1739760e0063SKevin Wolf     return bdrv_get_block_status_above(bs, backing_bs(bs),
174067a0fd2aSFam Zheng                                        sector_num, nb_sectors, pnum, file);
1741ba3f0e25SFam Zheng }
1742ba3f0e25SFam Zheng 
174361007b31SStefan Hajnoczi int coroutine_fn bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num,
174461007b31SStefan Hajnoczi                                    int nb_sectors, int *pnum)
174561007b31SStefan Hajnoczi {
174667a0fd2aSFam Zheng     BlockDriverState *file;
174767a0fd2aSFam Zheng     int64_t ret = bdrv_get_block_status(bs, sector_num, nb_sectors, pnum,
174867a0fd2aSFam Zheng                                         &file);
174961007b31SStefan Hajnoczi     if (ret < 0) {
175061007b31SStefan Hajnoczi         return ret;
175161007b31SStefan Hajnoczi     }
175261007b31SStefan Hajnoczi     return !!(ret & BDRV_BLOCK_ALLOCATED);
175361007b31SStefan Hajnoczi }
175461007b31SStefan Hajnoczi 
175561007b31SStefan Hajnoczi /*
175661007b31SStefan Hajnoczi  * Given an image chain: ... -> [BASE] -> [INTER1] -> [INTER2] -> [TOP]
175761007b31SStefan Hajnoczi  *
175861007b31SStefan Hajnoczi  * Return true if the given sector is allocated in any image between
175961007b31SStefan Hajnoczi  * BASE and TOP (inclusive).  BASE can be NULL to check if the given
176061007b31SStefan Hajnoczi  * sector is allocated in any image of the chain.  Return false otherwise.
176161007b31SStefan Hajnoczi  *
176261007b31SStefan Hajnoczi  * 'pnum' is set to the number of sectors (including and immediately following
176361007b31SStefan Hajnoczi  *  the specified sector) that are known to be in the same
176461007b31SStefan Hajnoczi  *  allocated/unallocated state.
176561007b31SStefan Hajnoczi  *
176661007b31SStefan Hajnoczi  */
176761007b31SStefan Hajnoczi int bdrv_is_allocated_above(BlockDriverState *top,
176861007b31SStefan Hajnoczi                             BlockDriverState *base,
176961007b31SStefan Hajnoczi                             int64_t sector_num,
177061007b31SStefan Hajnoczi                             int nb_sectors, int *pnum)
177161007b31SStefan Hajnoczi {
177261007b31SStefan Hajnoczi     BlockDriverState *intermediate;
177361007b31SStefan Hajnoczi     int ret, n = nb_sectors;
177461007b31SStefan Hajnoczi 
177561007b31SStefan Hajnoczi     intermediate = top;
177661007b31SStefan Hajnoczi     while (intermediate && intermediate != base) {
177761007b31SStefan Hajnoczi         int pnum_inter;
177861007b31SStefan Hajnoczi         ret = bdrv_is_allocated(intermediate, sector_num, nb_sectors,
177961007b31SStefan Hajnoczi                                 &pnum_inter);
178061007b31SStefan Hajnoczi         if (ret < 0) {
178161007b31SStefan Hajnoczi             return ret;
178261007b31SStefan Hajnoczi         } else if (ret) {
178361007b31SStefan Hajnoczi             *pnum = pnum_inter;
178461007b31SStefan Hajnoczi             return 1;
178561007b31SStefan Hajnoczi         }
178661007b31SStefan Hajnoczi 
178761007b31SStefan Hajnoczi         /*
178861007b31SStefan Hajnoczi          * [sector_num, nb_sectors] is unallocated on top but intermediate
178961007b31SStefan Hajnoczi          * might have
179061007b31SStefan Hajnoczi          *
179161007b31SStefan Hajnoczi          * [sector_num+x, nr_sectors] allocated.
179261007b31SStefan Hajnoczi          */
179361007b31SStefan Hajnoczi         if (n > pnum_inter &&
179461007b31SStefan Hajnoczi             (intermediate == top ||
179561007b31SStefan Hajnoczi              sector_num + pnum_inter < intermediate->total_sectors)) {
179661007b31SStefan Hajnoczi             n = pnum_inter;
179761007b31SStefan Hajnoczi         }
179861007b31SStefan Hajnoczi 
1799760e0063SKevin Wolf         intermediate = backing_bs(intermediate);
180061007b31SStefan Hajnoczi     }
180161007b31SStefan Hajnoczi 
180261007b31SStefan Hajnoczi     *pnum = n;
180361007b31SStefan Hajnoczi     return 0;
180461007b31SStefan Hajnoczi }
180561007b31SStefan Hajnoczi 
180661007b31SStefan Hajnoczi int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
180761007b31SStefan Hajnoczi                           const uint8_t *buf, int nb_sectors)
180861007b31SStefan Hajnoczi {
180961007b31SStefan Hajnoczi     BlockDriver *drv = bs->drv;
181061007b31SStefan Hajnoczi     int ret;
181161007b31SStefan Hajnoczi 
181261007b31SStefan Hajnoczi     if (!drv) {
181361007b31SStefan Hajnoczi         return -ENOMEDIUM;
181461007b31SStefan Hajnoczi     }
181561007b31SStefan Hajnoczi     if (!drv->bdrv_write_compressed) {
181661007b31SStefan Hajnoczi         return -ENOTSUP;
181761007b31SStefan Hajnoczi     }
181861007b31SStefan Hajnoczi     ret = bdrv_check_request(bs, sector_num, nb_sectors);
181961007b31SStefan Hajnoczi     if (ret < 0) {
182061007b31SStefan Hajnoczi         return ret;
182161007b31SStefan Hajnoczi     }
182261007b31SStefan Hajnoczi 
182361007b31SStefan Hajnoczi     assert(QLIST_EMPTY(&bs->dirty_bitmaps));
182461007b31SStefan Hajnoczi 
182561007b31SStefan Hajnoczi     return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
182661007b31SStefan Hajnoczi }
182761007b31SStefan Hajnoczi 
182861007b31SStefan Hajnoczi int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
182961007b31SStefan Hajnoczi                       int64_t pos, int size)
183061007b31SStefan Hajnoczi {
183161007b31SStefan Hajnoczi     QEMUIOVector qiov;
183261007b31SStefan Hajnoczi     struct iovec iov = {
183361007b31SStefan Hajnoczi         .iov_base   = (void *) buf,
183461007b31SStefan Hajnoczi         .iov_len    = size,
183561007b31SStefan Hajnoczi     };
183661007b31SStefan Hajnoczi 
183761007b31SStefan Hajnoczi     qemu_iovec_init_external(&qiov, &iov, 1);
183861007b31SStefan Hajnoczi     return bdrv_writev_vmstate(bs, &qiov, pos);
183961007b31SStefan Hajnoczi }
184061007b31SStefan Hajnoczi 
184161007b31SStefan Hajnoczi int bdrv_writev_vmstate(BlockDriverState *bs, QEMUIOVector *qiov, int64_t pos)
184261007b31SStefan Hajnoczi {
184361007b31SStefan Hajnoczi     BlockDriver *drv = bs->drv;
184461007b31SStefan Hajnoczi 
184561007b31SStefan Hajnoczi     if (!drv) {
184661007b31SStefan Hajnoczi         return -ENOMEDIUM;
184761007b31SStefan Hajnoczi     } else if (drv->bdrv_save_vmstate) {
184861007b31SStefan Hajnoczi         return drv->bdrv_save_vmstate(bs, qiov, pos);
184961007b31SStefan Hajnoczi     } else if (bs->file) {
18509a4f4c31SKevin Wolf         return bdrv_writev_vmstate(bs->file->bs, qiov, pos);
185161007b31SStefan Hajnoczi     }
185261007b31SStefan Hajnoczi 
185361007b31SStefan Hajnoczi     return -ENOTSUP;
185461007b31SStefan Hajnoczi }
185561007b31SStefan Hajnoczi 
185661007b31SStefan Hajnoczi int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
185761007b31SStefan Hajnoczi                       int64_t pos, int size)
185861007b31SStefan Hajnoczi {
185961007b31SStefan Hajnoczi     BlockDriver *drv = bs->drv;
186061007b31SStefan Hajnoczi     if (!drv)
186161007b31SStefan Hajnoczi         return -ENOMEDIUM;
186261007b31SStefan Hajnoczi     if (drv->bdrv_load_vmstate)
186361007b31SStefan Hajnoczi         return drv->bdrv_load_vmstate(bs, buf, pos, size);
186461007b31SStefan Hajnoczi     if (bs->file)
18659a4f4c31SKevin Wolf         return bdrv_load_vmstate(bs->file->bs, buf, pos, size);
186661007b31SStefan Hajnoczi     return -ENOTSUP;
186761007b31SStefan Hajnoczi }
186861007b31SStefan Hajnoczi 
186961007b31SStefan Hajnoczi /**************************************************************/
187061007b31SStefan Hajnoczi /* async I/Os */
187161007b31SStefan Hajnoczi 
187261007b31SStefan Hajnoczi BlockAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
187361007b31SStefan Hajnoczi                            QEMUIOVector *qiov, int nb_sectors,
187461007b31SStefan Hajnoczi                            BlockCompletionFunc *cb, void *opaque)
187561007b31SStefan Hajnoczi {
187661007b31SStefan Hajnoczi     trace_bdrv_aio_readv(bs, sector_num, nb_sectors, opaque);
187761007b31SStefan Hajnoczi 
187861007b31SStefan Hajnoczi     return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0,
187961007b31SStefan Hajnoczi                                  cb, opaque, false);
188061007b31SStefan Hajnoczi }
188161007b31SStefan Hajnoczi 
188261007b31SStefan Hajnoczi BlockAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
188361007b31SStefan Hajnoczi                             QEMUIOVector *qiov, int nb_sectors,
188461007b31SStefan Hajnoczi                             BlockCompletionFunc *cb, void *opaque)
188561007b31SStefan Hajnoczi {
188661007b31SStefan Hajnoczi     trace_bdrv_aio_writev(bs, sector_num, nb_sectors, opaque);
188761007b31SStefan Hajnoczi 
188861007b31SStefan Hajnoczi     return bdrv_co_aio_rw_vector(bs, sector_num, qiov, nb_sectors, 0,
188961007b31SStefan Hajnoczi                                  cb, opaque, true);
189061007b31SStefan Hajnoczi }
189161007b31SStefan Hajnoczi 
189261007b31SStefan Hajnoczi void bdrv_aio_cancel(BlockAIOCB *acb)
189361007b31SStefan Hajnoczi {
189461007b31SStefan Hajnoczi     qemu_aio_ref(acb);
189561007b31SStefan Hajnoczi     bdrv_aio_cancel_async(acb);
189661007b31SStefan Hajnoczi     while (acb->refcnt > 1) {
189761007b31SStefan Hajnoczi         if (acb->aiocb_info->get_aio_context) {
189861007b31SStefan Hajnoczi             aio_poll(acb->aiocb_info->get_aio_context(acb), true);
189961007b31SStefan Hajnoczi         } else if (acb->bs) {
190061007b31SStefan Hajnoczi             aio_poll(bdrv_get_aio_context(acb->bs), true);
190161007b31SStefan Hajnoczi         } else {
190261007b31SStefan Hajnoczi             abort();
190361007b31SStefan Hajnoczi         }
190461007b31SStefan Hajnoczi     }
190561007b31SStefan Hajnoczi     qemu_aio_unref(acb);
190661007b31SStefan Hajnoczi }
190761007b31SStefan Hajnoczi 
190861007b31SStefan Hajnoczi /* Async version of aio cancel. The caller is not blocked if the acb implements
190961007b31SStefan Hajnoczi  * cancel_async, otherwise we do nothing and let the request normally complete.
191061007b31SStefan Hajnoczi  * In either case the completion callback must be called. */
191161007b31SStefan Hajnoczi void bdrv_aio_cancel_async(BlockAIOCB *acb)
191261007b31SStefan Hajnoczi {
191361007b31SStefan Hajnoczi     if (acb->aiocb_info->cancel_async) {
191461007b31SStefan Hajnoczi         acb->aiocb_info->cancel_async(acb);
191561007b31SStefan Hajnoczi     }
191661007b31SStefan Hajnoczi }
191761007b31SStefan Hajnoczi 
191861007b31SStefan Hajnoczi /**************************************************************/
191961007b31SStefan Hajnoczi /* async block device emulation */
192061007b31SStefan Hajnoczi 
192141574268SEric Blake typedef struct BlockRequest {
192241574268SEric Blake     union {
192341574268SEric Blake         /* Used during read, write, trim */
192441574268SEric Blake         struct {
192541574268SEric Blake             int64_t sector;
192641574268SEric Blake             int nb_sectors;
192741574268SEric Blake             int flags;
192841574268SEric Blake             QEMUIOVector *qiov;
192941574268SEric Blake         };
193041574268SEric Blake         /* Used during ioctl */
193141574268SEric Blake         struct {
193241574268SEric Blake             int req;
193341574268SEric Blake             void *buf;
193441574268SEric Blake         };
193541574268SEric Blake     };
193641574268SEric Blake     BlockCompletionFunc *cb;
193741574268SEric Blake     void *opaque;
193841574268SEric Blake 
193941574268SEric Blake     int error;
194041574268SEric Blake } BlockRequest;
194141574268SEric Blake 
194261007b31SStefan Hajnoczi typedef struct BlockAIOCBCoroutine {
194361007b31SStefan Hajnoczi     BlockAIOCB common;
194461007b31SStefan Hajnoczi     BlockRequest req;
194561007b31SStefan Hajnoczi     bool is_write;
194661007b31SStefan Hajnoczi     bool need_bh;
194761007b31SStefan Hajnoczi     bool *done;
194861007b31SStefan Hajnoczi     QEMUBH* bh;
194961007b31SStefan Hajnoczi } BlockAIOCBCoroutine;
195061007b31SStefan Hajnoczi 
195161007b31SStefan Hajnoczi static const AIOCBInfo bdrv_em_co_aiocb_info = {
195261007b31SStefan Hajnoczi     .aiocb_size         = sizeof(BlockAIOCBCoroutine),
195361007b31SStefan Hajnoczi };
195461007b31SStefan Hajnoczi 
195561007b31SStefan Hajnoczi static void bdrv_co_complete(BlockAIOCBCoroutine *acb)
195661007b31SStefan Hajnoczi {
195761007b31SStefan Hajnoczi     if (!acb->need_bh) {
195861007b31SStefan Hajnoczi         acb->common.cb(acb->common.opaque, acb->req.error);
195961007b31SStefan Hajnoczi         qemu_aio_unref(acb);
196061007b31SStefan Hajnoczi     }
196161007b31SStefan Hajnoczi }
196261007b31SStefan Hajnoczi 
196361007b31SStefan Hajnoczi static void bdrv_co_em_bh(void *opaque)
196461007b31SStefan Hajnoczi {
196561007b31SStefan Hajnoczi     BlockAIOCBCoroutine *acb = opaque;
196661007b31SStefan Hajnoczi 
196761007b31SStefan Hajnoczi     assert(!acb->need_bh);
196861007b31SStefan Hajnoczi     qemu_bh_delete(acb->bh);
196961007b31SStefan Hajnoczi     bdrv_co_complete(acb);
197061007b31SStefan Hajnoczi }
197161007b31SStefan Hajnoczi 
197261007b31SStefan Hajnoczi static void bdrv_co_maybe_schedule_bh(BlockAIOCBCoroutine *acb)
197361007b31SStefan Hajnoczi {
197461007b31SStefan Hajnoczi     acb->need_bh = false;
197561007b31SStefan Hajnoczi     if (acb->req.error != -EINPROGRESS) {
197661007b31SStefan Hajnoczi         BlockDriverState *bs = acb->common.bs;
197761007b31SStefan Hajnoczi 
197861007b31SStefan Hajnoczi         acb->bh = aio_bh_new(bdrv_get_aio_context(bs), bdrv_co_em_bh, acb);
197961007b31SStefan Hajnoczi         qemu_bh_schedule(acb->bh);
198061007b31SStefan Hajnoczi     }
198161007b31SStefan Hajnoczi }
198261007b31SStefan Hajnoczi 
198361007b31SStefan Hajnoczi /* Invoke bdrv_co_do_readv/bdrv_co_do_writev */
198461007b31SStefan Hajnoczi static void coroutine_fn bdrv_co_do_rw(void *opaque)
198561007b31SStefan Hajnoczi {
198661007b31SStefan Hajnoczi     BlockAIOCBCoroutine *acb = opaque;
198761007b31SStefan Hajnoczi     BlockDriverState *bs = acb->common.bs;
198861007b31SStefan Hajnoczi 
198961007b31SStefan Hajnoczi     if (!acb->is_write) {
199061007b31SStefan Hajnoczi         acb->req.error = bdrv_co_do_readv(bs, acb->req.sector,
199161007b31SStefan Hajnoczi             acb->req.nb_sectors, acb->req.qiov, acb->req.flags);
199261007b31SStefan Hajnoczi     } else {
199361007b31SStefan Hajnoczi         acb->req.error = bdrv_co_do_writev(bs, acb->req.sector,
199461007b31SStefan Hajnoczi             acb->req.nb_sectors, acb->req.qiov, acb->req.flags);
199561007b31SStefan Hajnoczi     }
199661007b31SStefan Hajnoczi 
199761007b31SStefan Hajnoczi     bdrv_co_complete(acb);
199861007b31SStefan Hajnoczi }
199961007b31SStefan Hajnoczi 
200061007b31SStefan Hajnoczi static BlockAIOCB *bdrv_co_aio_rw_vector(BlockDriverState *bs,
200161007b31SStefan Hajnoczi                                          int64_t sector_num,
200261007b31SStefan Hajnoczi                                          QEMUIOVector *qiov,
200361007b31SStefan Hajnoczi                                          int nb_sectors,
200461007b31SStefan Hajnoczi                                          BdrvRequestFlags flags,
200561007b31SStefan Hajnoczi                                          BlockCompletionFunc *cb,
200661007b31SStefan Hajnoczi                                          void *opaque,
200761007b31SStefan Hajnoczi                                          bool is_write)
200861007b31SStefan Hajnoczi {
200961007b31SStefan Hajnoczi     Coroutine *co;
201061007b31SStefan Hajnoczi     BlockAIOCBCoroutine *acb;
201161007b31SStefan Hajnoczi 
201261007b31SStefan Hajnoczi     acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
201361007b31SStefan Hajnoczi     acb->need_bh = true;
201461007b31SStefan Hajnoczi     acb->req.error = -EINPROGRESS;
201561007b31SStefan Hajnoczi     acb->req.sector = sector_num;
201661007b31SStefan Hajnoczi     acb->req.nb_sectors = nb_sectors;
201761007b31SStefan Hajnoczi     acb->req.qiov = qiov;
201861007b31SStefan Hajnoczi     acb->req.flags = flags;
201961007b31SStefan Hajnoczi     acb->is_write = is_write;
202061007b31SStefan Hajnoczi 
202161007b31SStefan Hajnoczi     co = qemu_coroutine_create(bdrv_co_do_rw);
202261007b31SStefan Hajnoczi     qemu_coroutine_enter(co, acb);
202361007b31SStefan Hajnoczi 
202461007b31SStefan Hajnoczi     bdrv_co_maybe_schedule_bh(acb);
202561007b31SStefan Hajnoczi     return &acb->common;
202661007b31SStefan Hajnoczi }
202761007b31SStefan Hajnoczi 
202861007b31SStefan Hajnoczi static void coroutine_fn bdrv_aio_flush_co_entry(void *opaque)
202961007b31SStefan Hajnoczi {
203061007b31SStefan Hajnoczi     BlockAIOCBCoroutine *acb = opaque;
203161007b31SStefan Hajnoczi     BlockDriverState *bs = acb->common.bs;
203261007b31SStefan Hajnoczi 
203361007b31SStefan Hajnoczi     acb->req.error = bdrv_co_flush(bs);
203461007b31SStefan Hajnoczi     bdrv_co_complete(acb);
203561007b31SStefan Hajnoczi }
203661007b31SStefan Hajnoczi 
203761007b31SStefan Hajnoczi BlockAIOCB *bdrv_aio_flush(BlockDriverState *bs,
203861007b31SStefan Hajnoczi         BlockCompletionFunc *cb, void *opaque)
203961007b31SStefan Hajnoczi {
204061007b31SStefan Hajnoczi     trace_bdrv_aio_flush(bs, opaque);
204161007b31SStefan Hajnoczi 
204261007b31SStefan Hajnoczi     Coroutine *co;
204361007b31SStefan Hajnoczi     BlockAIOCBCoroutine *acb;
204461007b31SStefan Hajnoczi 
204561007b31SStefan Hajnoczi     acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
204661007b31SStefan Hajnoczi     acb->need_bh = true;
204761007b31SStefan Hajnoczi     acb->req.error = -EINPROGRESS;
204861007b31SStefan Hajnoczi 
204961007b31SStefan Hajnoczi     co = qemu_coroutine_create(bdrv_aio_flush_co_entry);
205061007b31SStefan Hajnoczi     qemu_coroutine_enter(co, acb);
205161007b31SStefan Hajnoczi 
205261007b31SStefan Hajnoczi     bdrv_co_maybe_schedule_bh(acb);
205361007b31SStefan Hajnoczi     return &acb->common;
205461007b31SStefan Hajnoczi }
205561007b31SStefan Hajnoczi 
205661007b31SStefan Hajnoczi static void coroutine_fn bdrv_aio_discard_co_entry(void *opaque)
205761007b31SStefan Hajnoczi {
205861007b31SStefan Hajnoczi     BlockAIOCBCoroutine *acb = opaque;
205961007b31SStefan Hajnoczi     BlockDriverState *bs = acb->common.bs;
206061007b31SStefan Hajnoczi 
206161007b31SStefan Hajnoczi     acb->req.error = bdrv_co_discard(bs, acb->req.sector, acb->req.nb_sectors);
206261007b31SStefan Hajnoczi     bdrv_co_complete(acb);
206361007b31SStefan Hajnoczi }
206461007b31SStefan Hajnoczi 
206561007b31SStefan Hajnoczi BlockAIOCB *bdrv_aio_discard(BlockDriverState *bs,
206661007b31SStefan Hajnoczi         int64_t sector_num, int nb_sectors,
206761007b31SStefan Hajnoczi         BlockCompletionFunc *cb, void *opaque)
206861007b31SStefan Hajnoczi {
206961007b31SStefan Hajnoczi     Coroutine *co;
207061007b31SStefan Hajnoczi     BlockAIOCBCoroutine *acb;
207161007b31SStefan Hajnoczi 
207261007b31SStefan Hajnoczi     trace_bdrv_aio_discard(bs, sector_num, nb_sectors, opaque);
207361007b31SStefan Hajnoczi 
207461007b31SStefan Hajnoczi     acb = qemu_aio_get(&bdrv_em_co_aiocb_info, bs, cb, opaque);
207561007b31SStefan Hajnoczi     acb->need_bh = true;
207661007b31SStefan Hajnoczi     acb->req.error = -EINPROGRESS;
207761007b31SStefan Hajnoczi     acb->req.sector = sector_num;
207861007b31SStefan Hajnoczi     acb->req.nb_sectors = nb_sectors;
207961007b31SStefan Hajnoczi     co = qemu_coroutine_create(bdrv_aio_discard_co_entry);
208061007b31SStefan Hajnoczi     qemu_coroutine_enter(co, acb);
208161007b31SStefan Hajnoczi 
208261007b31SStefan Hajnoczi     bdrv_co_maybe_schedule_bh(acb);
208361007b31SStefan Hajnoczi     return &acb->common;
208461007b31SStefan Hajnoczi }
208561007b31SStefan Hajnoczi 
208661007b31SStefan Hajnoczi void *qemu_aio_get(const AIOCBInfo *aiocb_info, BlockDriverState *bs,
208761007b31SStefan Hajnoczi                    BlockCompletionFunc *cb, void *opaque)
208861007b31SStefan Hajnoczi {
208961007b31SStefan Hajnoczi     BlockAIOCB *acb;
209061007b31SStefan Hajnoczi 
2091c84b3192SPaolo Bonzini     acb = g_malloc(aiocb_info->aiocb_size);
209261007b31SStefan Hajnoczi     acb->aiocb_info = aiocb_info;
209361007b31SStefan Hajnoczi     acb->bs = bs;
209461007b31SStefan Hajnoczi     acb->cb = cb;
209561007b31SStefan Hajnoczi     acb->opaque = opaque;
209661007b31SStefan Hajnoczi     acb->refcnt = 1;
209761007b31SStefan Hajnoczi     return acb;
209861007b31SStefan Hajnoczi }
209961007b31SStefan Hajnoczi 
210061007b31SStefan Hajnoczi void qemu_aio_ref(void *p)
210161007b31SStefan Hajnoczi {
210261007b31SStefan Hajnoczi     BlockAIOCB *acb = p;
210361007b31SStefan Hajnoczi     acb->refcnt++;
210461007b31SStefan Hajnoczi }
210561007b31SStefan Hajnoczi 
210661007b31SStefan Hajnoczi void qemu_aio_unref(void *p)
210761007b31SStefan Hajnoczi {
210861007b31SStefan Hajnoczi     BlockAIOCB *acb = p;
210961007b31SStefan Hajnoczi     assert(acb->refcnt > 0);
211061007b31SStefan Hajnoczi     if (--acb->refcnt == 0) {
2111c84b3192SPaolo Bonzini         g_free(acb);
211261007b31SStefan Hajnoczi     }
211361007b31SStefan Hajnoczi }
211461007b31SStefan Hajnoczi 
211561007b31SStefan Hajnoczi /**************************************************************/
211661007b31SStefan Hajnoczi /* Coroutine block device emulation */
211761007b31SStefan Hajnoczi 
211861007b31SStefan Hajnoczi static void coroutine_fn bdrv_flush_co_entry(void *opaque)
211961007b31SStefan Hajnoczi {
212061007b31SStefan Hajnoczi     RwCo *rwco = opaque;
212161007b31SStefan Hajnoczi 
212261007b31SStefan Hajnoczi     rwco->ret = bdrv_co_flush(rwco->bs);
212361007b31SStefan Hajnoczi }
212461007b31SStefan Hajnoczi 
212561007b31SStefan Hajnoczi int coroutine_fn bdrv_co_flush(BlockDriverState *bs)
212661007b31SStefan Hajnoczi {
212761007b31SStefan Hajnoczi     int ret;
2128cdb5e315SFam Zheng     BdrvTrackedRequest req;
212961007b31SStefan Hajnoczi 
21301b6bc94dSDimitris Aragiorgis     if (!bs || !bdrv_is_inserted(bs) || bdrv_is_read_only(bs) ||
21311b6bc94dSDimitris Aragiorgis         bdrv_is_sg(bs)) {
213261007b31SStefan Hajnoczi         return 0;
213361007b31SStefan Hajnoczi     }
213461007b31SStefan Hajnoczi 
2135cdb5e315SFam Zheng     tracked_request_begin(&req, bs, 0, 0, BDRV_TRACKED_FLUSH);
2136c32b82afSPavel Dovgalyuk 
2137c32b82afSPavel Dovgalyuk     /* Write back all layers by calling one driver function */
2138c32b82afSPavel Dovgalyuk     if (bs->drv->bdrv_co_flush) {
2139c32b82afSPavel Dovgalyuk         ret = bs->drv->bdrv_co_flush(bs);
2140c32b82afSPavel Dovgalyuk         goto out;
2141c32b82afSPavel Dovgalyuk     }
2142c32b82afSPavel Dovgalyuk 
214361007b31SStefan Hajnoczi     /* Write back cached data to the OS even with cache=unsafe */
214461007b31SStefan Hajnoczi     BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_OS);
214561007b31SStefan Hajnoczi     if (bs->drv->bdrv_co_flush_to_os) {
214661007b31SStefan Hajnoczi         ret = bs->drv->bdrv_co_flush_to_os(bs);
214761007b31SStefan Hajnoczi         if (ret < 0) {
2148cdb5e315SFam Zheng             goto out;
214961007b31SStefan Hajnoczi         }
215061007b31SStefan Hajnoczi     }
215161007b31SStefan Hajnoczi 
215261007b31SStefan Hajnoczi     /* But don't actually force it to the disk with cache=unsafe */
215361007b31SStefan Hajnoczi     if (bs->open_flags & BDRV_O_NO_FLUSH) {
215461007b31SStefan Hajnoczi         goto flush_parent;
215561007b31SStefan Hajnoczi     }
215661007b31SStefan Hajnoczi 
215761007b31SStefan Hajnoczi     BLKDBG_EVENT(bs->file, BLKDBG_FLUSH_TO_DISK);
215861007b31SStefan Hajnoczi     if (bs->drv->bdrv_co_flush_to_disk) {
215961007b31SStefan Hajnoczi         ret = bs->drv->bdrv_co_flush_to_disk(bs);
216061007b31SStefan Hajnoczi     } else if (bs->drv->bdrv_aio_flush) {
216161007b31SStefan Hajnoczi         BlockAIOCB *acb;
216261007b31SStefan Hajnoczi         CoroutineIOCompletion co = {
216361007b31SStefan Hajnoczi             .coroutine = qemu_coroutine_self(),
216461007b31SStefan Hajnoczi         };
216561007b31SStefan Hajnoczi 
216661007b31SStefan Hajnoczi         acb = bs->drv->bdrv_aio_flush(bs, bdrv_co_io_em_complete, &co);
216761007b31SStefan Hajnoczi         if (acb == NULL) {
216861007b31SStefan Hajnoczi             ret = -EIO;
216961007b31SStefan Hajnoczi         } else {
217061007b31SStefan Hajnoczi             qemu_coroutine_yield();
217161007b31SStefan Hajnoczi             ret = co.ret;
217261007b31SStefan Hajnoczi         }
217361007b31SStefan Hajnoczi     } else {
217461007b31SStefan Hajnoczi         /*
217561007b31SStefan Hajnoczi          * Some block drivers always operate in either writethrough or unsafe
217661007b31SStefan Hajnoczi          * mode and don't support bdrv_flush therefore. Usually qemu doesn't
217761007b31SStefan Hajnoczi          * know how the server works (because the behaviour is hardcoded or
217861007b31SStefan Hajnoczi          * depends on server-side configuration), so we can't ensure that
217961007b31SStefan Hajnoczi          * everything is safe on disk. Returning an error doesn't work because
218061007b31SStefan Hajnoczi          * that would break guests even if the server operates in writethrough
218161007b31SStefan Hajnoczi          * mode.
218261007b31SStefan Hajnoczi          *
218361007b31SStefan Hajnoczi          * Let's hope the user knows what he's doing.
218461007b31SStefan Hajnoczi          */
218561007b31SStefan Hajnoczi         ret = 0;
218661007b31SStefan Hajnoczi     }
218761007b31SStefan Hajnoczi     if (ret < 0) {
2188cdb5e315SFam Zheng         goto out;
218961007b31SStefan Hajnoczi     }
219061007b31SStefan Hajnoczi 
219161007b31SStefan Hajnoczi     /* Now flush the underlying protocol.  It will also have BDRV_O_NO_FLUSH
219261007b31SStefan Hajnoczi      * in the case of cache=unsafe, so there are no useless flushes.
219361007b31SStefan Hajnoczi      */
219461007b31SStefan Hajnoczi flush_parent:
2195cdb5e315SFam Zheng     ret = bs->file ? bdrv_co_flush(bs->file->bs) : 0;
2196cdb5e315SFam Zheng out:
2197cdb5e315SFam Zheng     tracked_request_end(&req);
2198cdb5e315SFam Zheng     return ret;
219961007b31SStefan Hajnoczi }
220061007b31SStefan Hajnoczi 
220161007b31SStefan Hajnoczi int bdrv_flush(BlockDriverState *bs)
220261007b31SStefan Hajnoczi {
220361007b31SStefan Hajnoczi     Coroutine *co;
220461007b31SStefan Hajnoczi     RwCo rwco = {
220561007b31SStefan Hajnoczi         .bs = bs,
220661007b31SStefan Hajnoczi         .ret = NOT_DONE,
220761007b31SStefan Hajnoczi     };
220861007b31SStefan Hajnoczi 
220961007b31SStefan Hajnoczi     if (qemu_in_coroutine()) {
221061007b31SStefan Hajnoczi         /* Fast-path if already in coroutine context */
221161007b31SStefan Hajnoczi         bdrv_flush_co_entry(&rwco);
221261007b31SStefan Hajnoczi     } else {
221361007b31SStefan Hajnoczi         AioContext *aio_context = bdrv_get_aio_context(bs);
221461007b31SStefan Hajnoczi 
221561007b31SStefan Hajnoczi         co = qemu_coroutine_create(bdrv_flush_co_entry);
221661007b31SStefan Hajnoczi         qemu_coroutine_enter(co, &rwco);
221761007b31SStefan Hajnoczi         while (rwco.ret == NOT_DONE) {
221861007b31SStefan Hajnoczi             aio_poll(aio_context, true);
221961007b31SStefan Hajnoczi         }
222061007b31SStefan Hajnoczi     }
222161007b31SStefan Hajnoczi 
222261007b31SStefan Hajnoczi     return rwco.ret;
222361007b31SStefan Hajnoczi }
222461007b31SStefan Hajnoczi 
222561007b31SStefan Hajnoczi typedef struct DiscardCo {
222661007b31SStefan Hajnoczi     BlockDriverState *bs;
222761007b31SStefan Hajnoczi     int64_t sector_num;
222861007b31SStefan Hajnoczi     int nb_sectors;
222961007b31SStefan Hajnoczi     int ret;
223061007b31SStefan Hajnoczi } DiscardCo;
223161007b31SStefan Hajnoczi static void coroutine_fn bdrv_discard_co_entry(void *opaque)
223261007b31SStefan Hajnoczi {
223361007b31SStefan Hajnoczi     DiscardCo *rwco = opaque;
223461007b31SStefan Hajnoczi 
223561007b31SStefan Hajnoczi     rwco->ret = bdrv_co_discard(rwco->bs, rwco->sector_num, rwco->nb_sectors);
223661007b31SStefan Hajnoczi }
223761007b31SStefan Hajnoczi 
223861007b31SStefan Hajnoczi int coroutine_fn bdrv_co_discard(BlockDriverState *bs, int64_t sector_num,
223961007b31SStefan Hajnoczi                                  int nb_sectors)
224061007b31SStefan Hajnoczi {
2241b1066c87SFam Zheng     BdrvTrackedRequest req;
224261007b31SStefan Hajnoczi     int max_discard, ret;
224361007b31SStefan Hajnoczi 
224461007b31SStefan Hajnoczi     if (!bs->drv) {
224561007b31SStefan Hajnoczi         return -ENOMEDIUM;
224661007b31SStefan Hajnoczi     }
224761007b31SStefan Hajnoczi 
224861007b31SStefan Hajnoczi     ret = bdrv_check_request(bs, sector_num, nb_sectors);
224961007b31SStefan Hajnoczi     if (ret < 0) {
225061007b31SStefan Hajnoczi         return ret;
225161007b31SStefan Hajnoczi     } else if (bs->read_only) {
2252eaf5fe2dSPaolo Bonzini         return -EPERM;
225361007b31SStefan Hajnoczi     }
225404c01a5cSKevin Wolf     assert(!(bs->open_flags & BDRV_O_INACTIVE));
225561007b31SStefan Hajnoczi 
225661007b31SStefan Hajnoczi     /* Do nothing if disabled.  */
225761007b31SStefan Hajnoczi     if (!(bs->open_flags & BDRV_O_UNMAP)) {
225861007b31SStefan Hajnoczi         return 0;
225961007b31SStefan Hajnoczi     }
226061007b31SStefan Hajnoczi 
226161007b31SStefan Hajnoczi     if (!bs->drv->bdrv_co_discard && !bs->drv->bdrv_aio_discard) {
226261007b31SStefan Hajnoczi         return 0;
226361007b31SStefan Hajnoczi     }
226461007b31SStefan Hajnoczi 
2265b1066c87SFam Zheng     tracked_request_begin(&req, bs, sector_num, nb_sectors,
2266b1066c87SFam Zheng                           BDRV_TRACKED_DISCARD);
226750824995SFam Zheng     bdrv_set_dirty(bs, sector_num, nb_sectors);
226850824995SFam Zheng 
226961007b31SStefan Hajnoczi     max_discard = MIN_NON_ZERO(bs->bl.max_discard, BDRV_REQUEST_MAX_SECTORS);
227061007b31SStefan Hajnoczi     while (nb_sectors > 0) {
227161007b31SStefan Hajnoczi         int ret;
227261007b31SStefan Hajnoczi         int num = nb_sectors;
227361007b31SStefan Hajnoczi 
227461007b31SStefan Hajnoczi         /* align request */
227561007b31SStefan Hajnoczi         if (bs->bl.discard_alignment &&
227661007b31SStefan Hajnoczi             num >= bs->bl.discard_alignment &&
227761007b31SStefan Hajnoczi             sector_num % bs->bl.discard_alignment) {
227861007b31SStefan Hajnoczi             if (num > bs->bl.discard_alignment) {
227961007b31SStefan Hajnoczi                 num = bs->bl.discard_alignment;
228061007b31SStefan Hajnoczi             }
228161007b31SStefan Hajnoczi             num -= sector_num % bs->bl.discard_alignment;
228261007b31SStefan Hajnoczi         }
228361007b31SStefan Hajnoczi 
228461007b31SStefan Hajnoczi         /* limit request size */
228561007b31SStefan Hajnoczi         if (num > max_discard) {
228661007b31SStefan Hajnoczi             num = max_discard;
228761007b31SStefan Hajnoczi         }
228861007b31SStefan Hajnoczi 
228961007b31SStefan Hajnoczi         if (bs->drv->bdrv_co_discard) {
229061007b31SStefan Hajnoczi             ret = bs->drv->bdrv_co_discard(bs, sector_num, num);
229161007b31SStefan Hajnoczi         } else {
229261007b31SStefan Hajnoczi             BlockAIOCB *acb;
229361007b31SStefan Hajnoczi             CoroutineIOCompletion co = {
229461007b31SStefan Hajnoczi                 .coroutine = qemu_coroutine_self(),
229561007b31SStefan Hajnoczi             };
229661007b31SStefan Hajnoczi 
229761007b31SStefan Hajnoczi             acb = bs->drv->bdrv_aio_discard(bs, sector_num, nb_sectors,
229861007b31SStefan Hajnoczi                                             bdrv_co_io_em_complete, &co);
229961007b31SStefan Hajnoczi             if (acb == NULL) {
2300b1066c87SFam Zheng                 ret = -EIO;
2301b1066c87SFam Zheng                 goto out;
230261007b31SStefan Hajnoczi             } else {
230361007b31SStefan Hajnoczi                 qemu_coroutine_yield();
230461007b31SStefan Hajnoczi                 ret = co.ret;
230561007b31SStefan Hajnoczi             }
230661007b31SStefan Hajnoczi         }
230761007b31SStefan Hajnoczi         if (ret && ret != -ENOTSUP) {
2308b1066c87SFam Zheng             goto out;
230961007b31SStefan Hajnoczi         }
231061007b31SStefan Hajnoczi 
231161007b31SStefan Hajnoczi         sector_num += num;
231261007b31SStefan Hajnoczi         nb_sectors -= num;
231361007b31SStefan Hajnoczi     }
2314b1066c87SFam Zheng     ret = 0;
2315b1066c87SFam Zheng out:
2316b1066c87SFam Zheng     tracked_request_end(&req);
2317b1066c87SFam Zheng     return ret;
231861007b31SStefan Hajnoczi }
231961007b31SStefan Hajnoczi 
232061007b31SStefan Hajnoczi int bdrv_discard(BlockDriverState *bs, int64_t sector_num, int nb_sectors)
232161007b31SStefan Hajnoczi {
232261007b31SStefan Hajnoczi     Coroutine *co;
232361007b31SStefan Hajnoczi     DiscardCo rwco = {
232461007b31SStefan Hajnoczi         .bs = bs,
232561007b31SStefan Hajnoczi         .sector_num = sector_num,
232661007b31SStefan Hajnoczi         .nb_sectors = nb_sectors,
232761007b31SStefan Hajnoczi         .ret = NOT_DONE,
232861007b31SStefan Hajnoczi     };
232961007b31SStefan Hajnoczi 
233061007b31SStefan Hajnoczi     if (qemu_in_coroutine()) {
233161007b31SStefan Hajnoczi         /* Fast-path if already in coroutine context */
233261007b31SStefan Hajnoczi         bdrv_discard_co_entry(&rwco);
233361007b31SStefan Hajnoczi     } else {
233461007b31SStefan Hajnoczi         AioContext *aio_context = bdrv_get_aio_context(bs);
233561007b31SStefan Hajnoczi 
233661007b31SStefan Hajnoczi         co = qemu_coroutine_create(bdrv_discard_co_entry);
233761007b31SStefan Hajnoczi         qemu_coroutine_enter(co, &rwco);
233861007b31SStefan Hajnoczi         while (rwco.ret == NOT_DONE) {
233961007b31SStefan Hajnoczi             aio_poll(aio_context, true);
234061007b31SStefan Hajnoczi         }
234161007b31SStefan Hajnoczi     }
234261007b31SStefan Hajnoczi 
234361007b31SStefan Hajnoczi     return rwco.ret;
234461007b31SStefan Hajnoczi }
234561007b31SStefan Hajnoczi 
23465c5ae76aSFam Zheng static int bdrv_co_do_ioctl(BlockDriverState *bs, int req, void *buf)
234761007b31SStefan Hajnoczi {
234861007b31SStefan Hajnoczi     BlockDriver *drv = bs->drv;
23495c5ae76aSFam Zheng     BdrvTrackedRequest tracked_req;
23505c5ae76aSFam Zheng     CoroutineIOCompletion co = {
23515c5ae76aSFam Zheng         .coroutine = qemu_coroutine_self(),
23525c5ae76aSFam Zheng     };
23535c5ae76aSFam Zheng     BlockAIOCB *acb;
235461007b31SStefan Hajnoczi 
23555c5ae76aSFam Zheng     tracked_request_begin(&tracked_req, bs, 0, 0, BDRV_TRACKED_IOCTL);
23565c5ae76aSFam Zheng     if (!drv || !drv->bdrv_aio_ioctl) {
23575c5ae76aSFam Zheng         co.ret = -ENOTSUP;
23585c5ae76aSFam Zheng         goto out;
23595c5ae76aSFam Zheng     }
23605c5ae76aSFam Zheng 
23615c5ae76aSFam Zheng     acb = drv->bdrv_aio_ioctl(bs, req, buf, bdrv_co_io_em_complete, &co);
23625c5ae76aSFam Zheng     if (!acb) {
2363c8a9fd80SFam Zheng         co.ret = -ENOTSUP;
2364c8a9fd80SFam Zheng         goto out;
23655c5ae76aSFam Zheng     }
23665c5ae76aSFam Zheng     qemu_coroutine_yield();
23675c5ae76aSFam Zheng out:
23685c5ae76aSFam Zheng     tracked_request_end(&tracked_req);
23695c5ae76aSFam Zheng     return co.ret;
23705c5ae76aSFam Zheng }
23715c5ae76aSFam Zheng 
23725c5ae76aSFam Zheng typedef struct {
23735c5ae76aSFam Zheng     BlockDriverState *bs;
23745c5ae76aSFam Zheng     int req;
23755c5ae76aSFam Zheng     void *buf;
23765c5ae76aSFam Zheng     int ret;
23775c5ae76aSFam Zheng } BdrvIoctlCoData;
23785c5ae76aSFam Zheng 
23795c5ae76aSFam Zheng static void coroutine_fn bdrv_co_ioctl_entry(void *opaque)
23805c5ae76aSFam Zheng {
23815c5ae76aSFam Zheng     BdrvIoctlCoData *data = opaque;
23825c5ae76aSFam Zheng     data->ret = bdrv_co_do_ioctl(data->bs, data->req, data->buf);
23835c5ae76aSFam Zheng }
23845c5ae76aSFam Zheng 
23855c5ae76aSFam Zheng /* needed for generic scsi interface */
23865c5ae76aSFam Zheng int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
23875c5ae76aSFam Zheng {
23885c5ae76aSFam Zheng     BdrvIoctlCoData data = {
23895c5ae76aSFam Zheng         .bs = bs,
23905c5ae76aSFam Zheng         .req = req,
23915c5ae76aSFam Zheng         .buf = buf,
23925c5ae76aSFam Zheng         .ret = -EINPROGRESS,
23935c5ae76aSFam Zheng     };
23945c5ae76aSFam Zheng 
23955c5ae76aSFam Zheng     if (qemu_in_coroutine()) {
23965c5ae76aSFam Zheng         /* Fast-path if already in coroutine context */
23975c5ae76aSFam Zheng         bdrv_co_ioctl_entry(&data);
23985c5ae76aSFam Zheng     } else {
23995c5ae76aSFam Zheng         Coroutine *co = qemu_coroutine_create(bdrv_co_ioctl_entry);
2400ba889444SPaolo Bonzini 
24015c5ae76aSFam Zheng         qemu_coroutine_enter(co, &data);
24025c5ae76aSFam Zheng         while (data.ret == -EINPROGRESS) {
24035c5ae76aSFam Zheng             aio_poll(bdrv_get_aio_context(bs), true);
24045c5ae76aSFam Zheng         }
2405ba889444SPaolo Bonzini     }
24065c5ae76aSFam Zheng     return data.ret;
24075c5ae76aSFam Zheng }
24085c5ae76aSFam Zheng 
24095c5ae76aSFam Zheng static void coroutine_fn bdrv_co_aio_ioctl_entry(void *opaque)
24105c5ae76aSFam Zheng {
24115c5ae76aSFam Zheng     BlockAIOCBCoroutine *acb = opaque;
24125c5ae76aSFam Zheng     acb->req.error = bdrv_co_do_ioctl(acb->common.bs,
24135c5ae76aSFam Zheng                                       acb->req.req, acb->req.buf);
24145c5ae76aSFam Zheng     bdrv_co_complete(acb);
241561007b31SStefan Hajnoczi }
241661007b31SStefan Hajnoczi 
241761007b31SStefan Hajnoczi BlockAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
241861007b31SStefan Hajnoczi         unsigned long int req, void *buf,
241961007b31SStefan Hajnoczi         BlockCompletionFunc *cb, void *opaque)
242061007b31SStefan Hajnoczi {
24215c5ae76aSFam Zheng     BlockAIOCBCoroutine *acb = qemu_aio_get(&bdrv_em_co_aiocb_info,
24225c5ae76aSFam Zheng                                             bs, cb, opaque);
24235c5ae76aSFam Zheng     Coroutine *co;
242461007b31SStefan Hajnoczi 
24255c5ae76aSFam Zheng     acb->need_bh = true;
24265c5ae76aSFam Zheng     acb->req.error = -EINPROGRESS;
24275c5ae76aSFam Zheng     acb->req.req = req;
24285c5ae76aSFam Zheng     acb->req.buf = buf;
24295c5ae76aSFam Zheng     co = qemu_coroutine_create(bdrv_co_aio_ioctl_entry);
24305c5ae76aSFam Zheng     qemu_coroutine_enter(co, acb);
24315c5ae76aSFam Zheng 
24325c5ae76aSFam Zheng     bdrv_co_maybe_schedule_bh(acb);
24335c5ae76aSFam Zheng     return &acb->common;
243461007b31SStefan Hajnoczi }
243561007b31SStefan Hajnoczi 
243661007b31SStefan Hajnoczi void *qemu_blockalign(BlockDriverState *bs, size_t size)
243761007b31SStefan Hajnoczi {
243861007b31SStefan Hajnoczi     return qemu_memalign(bdrv_opt_mem_align(bs), size);
243961007b31SStefan Hajnoczi }
244061007b31SStefan Hajnoczi 
244161007b31SStefan Hajnoczi void *qemu_blockalign0(BlockDriverState *bs, size_t size)
244261007b31SStefan Hajnoczi {
244361007b31SStefan Hajnoczi     return memset(qemu_blockalign(bs, size), 0, size);
244461007b31SStefan Hajnoczi }
244561007b31SStefan Hajnoczi 
244661007b31SStefan Hajnoczi void *qemu_try_blockalign(BlockDriverState *bs, size_t size)
244761007b31SStefan Hajnoczi {
244861007b31SStefan Hajnoczi     size_t align = bdrv_opt_mem_align(bs);
244961007b31SStefan Hajnoczi 
245061007b31SStefan Hajnoczi     /* Ensure that NULL is never returned on success */
245161007b31SStefan Hajnoczi     assert(align > 0);
245261007b31SStefan Hajnoczi     if (size == 0) {
245361007b31SStefan Hajnoczi         size = align;
245461007b31SStefan Hajnoczi     }
245561007b31SStefan Hajnoczi 
245661007b31SStefan Hajnoczi     return qemu_try_memalign(align, size);
245761007b31SStefan Hajnoczi }
245861007b31SStefan Hajnoczi 
245961007b31SStefan Hajnoczi void *qemu_try_blockalign0(BlockDriverState *bs, size_t size)
246061007b31SStefan Hajnoczi {
246161007b31SStefan Hajnoczi     void *mem = qemu_try_blockalign(bs, size);
246261007b31SStefan Hajnoczi 
246361007b31SStefan Hajnoczi     if (mem) {
246461007b31SStefan Hajnoczi         memset(mem, 0, size);
246561007b31SStefan Hajnoczi     }
246661007b31SStefan Hajnoczi 
246761007b31SStefan Hajnoczi     return mem;
246861007b31SStefan Hajnoczi }
246961007b31SStefan Hajnoczi 
247061007b31SStefan Hajnoczi /*
247161007b31SStefan Hajnoczi  * Check if all memory in this vector is sector aligned.
247261007b31SStefan Hajnoczi  */
247361007b31SStefan Hajnoczi bool bdrv_qiov_is_aligned(BlockDriverState *bs, QEMUIOVector *qiov)
247461007b31SStefan Hajnoczi {
247561007b31SStefan Hajnoczi     int i;
24764196d2f0SDenis V. Lunev     size_t alignment = bdrv_min_mem_align(bs);
247761007b31SStefan Hajnoczi 
247861007b31SStefan Hajnoczi     for (i = 0; i < qiov->niov; i++) {
247961007b31SStefan Hajnoczi         if ((uintptr_t) qiov->iov[i].iov_base % alignment) {
248061007b31SStefan Hajnoczi             return false;
248161007b31SStefan Hajnoczi         }
248261007b31SStefan Hajnoczi         if (qiov->iov[i].iov_len % alignment) {
248361007b31SStefan Hajnoczi             return false;
248461007b31SStefan Hajnoczi         }
248561007b31SStefan Hajnoczi     }
248661007b31SStefan Hajnoczi 
248761007b31SStefan Hajnoczi     return true;
248861007b31SStefan Hajnoczi }
248961007b31SStefan Hajnoczi 
249061007b31SStefan Hajnoczi void bdrv_add_before_write_notifier(BlockDriverState *bs,
249161007b31SStefan Hajnoczi                                     NotifierWithReturn *notifier)
249261007b31SStefan Hajnoczi {
249361007b31SStefan Hajnoczi     notifier_with_return_list_add(&bs->before_write_notifiers, notifier);
249461007b31SStefan Hajnoczi }
249561007b31SStefan Hajnoczi 
249661007b31SStefan Hajnoczi void bdrv_io_plug(BlockDriverState *bs)
249761007b31SStefan Hajnoczi {
24986b98bd64SPaolo Bonzini     BdrvChild *child;
24996b98bd64SPaolo Bonzini 
25006b98bd64SPaolo Bonzini     QLIST_FOREACH(child, &bs->children, next) {
25016b98bd64SPaolo Bonzini         bdrv_io_plug(child->bs);
25026b98bd64SPaolo Bonzini     }
25036b98bd64SPaolo Bonzini 
25046b98bd64SPaolo Bonzini     if (bs->io_plugged++ == 0 && bs->io_plug_disabled == 0) {
250561007b31SStefan Hajnoczi         BlockDriver *drv = bs->drv;
250661007b31SStefan Hajnoczi         if (drv && drv->bdrv_io_plug) {
250761007b31SStefan Hajnoczi             drv->bdrv_io_plug(bs);
25086b98bd64SPaolo Bonzini         }
250961007b31SStefan Hajnoczi     }
251061007b31SStefan Hajnoczi }
251161007b31SStefan Hajnoczi 
251261007b31SStefan Hajnoczi void bdrv_io_unplug(BlockDriverState *bs)
251361007b31SStefan Hajnoczi {
25146b98bd64SPaolo Bonzini     BdrvChild *child;
25156b98bd64SPaolo Bonzini 
25166b98bd64SPaolo Bonzini     assert(bs->io_plugged);
25176b98bd64SPaolo Bonzini     if (--bs->io_plugged == 0 && bs->io_plug_disabled == 0) {
251861007b31SStefan Hajnoczi         BlockDriver *drv = bs->drv;
251961007b31SStefan Hajnoczi         if (drv && drv->bdrv_io_unplug) {
252061007b31SStefan Hajnoczi             drv->bdrv_io_unplug(bs);
252161007b31SStefan Hajnoczi         }
252261007b31SStefan Hajnoczi     }
252361007b31SStefan Hajnoczi 
25246b98bd64SPaolo Bonzini     QLIST_FOREACH(child, &bs->children, next) {
25256b98bd64SPaolo Bonzini         bdrv_io_unplug(child->bs);
25266b98bd64SPaolo Bonzini     }
25276b98bd64SPaolo Bonzini }
25286b98bd64SPaolo Bonzini 
25296b98bd64SPaolo Bonzini void bdrv_io_unplugged_begin(BlockDriverState *bs)
253061007b31SStefan Hajnoczi {
25316b98bd64SPaolo Bonzini     BdrvChild *child;
25326b98bd64SPaolo Bonzini 
25336b98bd64SPaolo Bonzini     if (bs->io_plug_disabled++ == 0 && bs->io_plugged > 0) {
253461007b31SStefan Hajnoczi         BlockDriver *drv = bs->drv;
25356b98bd64SPaolo Bonzini         if (drv && drv->bdrv_io_unplug) {
25366b98bd64SPaolo Bonzini             drv->bdrv_io_unplug(bs);
25376b98bd64SPaolo Bonzini         }
25386b98bd64SPaolo Bonzini     }
25396b98bd64SPaolo Bonzini 
25406b98bd64SPaolo Bonzini     QLIST_FOREACH(child, &bs->children, next) {
25416b98bd64SPaolo Bonzini         bdrv_io_unplugged_begin(child->bs);
25426b98bd64SPaolo Bonzini     }
25436b98bd64SPaolo Bonzini }
25446b98bd64SPaolo Bonzini 
25456b98bd64SPaolo Bonzini void bdrv_io_unplugged_end(BlockDriverState *bs)
25466b98bd64SPaolo Bonzini {
25476b98bd64SPaolo Bonzini     BdrvChild *child;
25486b98bd64SPaolo Bonzini 
25496b98bd64SPaolo Bonzini     assert(bs->io_plug_disabled);
25506b98bd64SPaolo Bonzini     QLIST_FOREACH(child, &bs->children, next) {
25516b98bd64SPaolo Bonzini         bdrv_io_unplugged_end(child->bs);
25526b98bd64SPaolo Bonzini     }
25536b98bd64SPaolo Bonzini 
25546b98bd64SPaolo Bonzini     if (--bs->io_plug_disabled == 0 && bs->io_plugged > 0) {
25556b98bd64SPaolo Bonzini         BlockDriver *drv = bs->drv;
25566b98bd64SPaolo Bonzini         if (drv && drv->bdrv_io_plug) {
25576b98bd64SPaolo Bonzini             drv->bdrv_io_plug(bs);
25586b98bd64SPaolo Bonzini         }
255961007b31SStefan Hajnoczi     }
256061007b31SStefan Hajnoczi }
2561