14f1043b4SStefan Hajnoczi /*
24f1043b4SStefan Hajnoczi * Image streaming
34f1043b4SStefan Hajnoczi *
44f1043b4SStefan Hajnoczi * Copyright IBM, Corp. 2011
54f1043b4SStefan Hajnoczi *
64f1043b4SStefan Hajnoczi * Authors:
74f1043b4SStefan Hajnoczi * Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
84f1043b4SStefan Hajnoczi *
94f1043b4SStefan Hajnoczi * This work is licensed under the terms of the GNU LGPL, version 2 or later.
104f1043b4SStefan Hajnoczi * See the COPYING.LIB file in the top-level directory.
114f1043b4SStefan Hajnoczi *
124f1043b4SStefan Hajnoczi */
134f1043b4SStefan Hajnoczi
1480c71a24SPeter Maydell #include "qemu/osdep.h"
154f1043b4SStefan Hajnoczi #include "trace.h"
16737e150eSPaolo Bonzini #include "block/block_int.h"
17c87621eaSJohn Snow #include "block/blockjob_int.h"
18da34e65cSMarkus Armbruster #include "qapi/error.h"
19205736f4SAndrey Shinkevich #include "qapi/qmp/qdict.h"
206ef228fcSPaolo Bonzini #include "qemu/ratelimit.h"
21373340b2SMax Reitz #include "sysemu/block-backend.h"
22205736f4SAndrey Shinkevich #include "block/copy-on-read.h"
234f1043b4SStefan Hajnoczi
244f1043b4SStefan Hajnoczi enum {
254f1043b4SStefan Hajnoczi /*
2699136607SVladimir Sementsov-Ogievskiy * Maximum chunk size to feed to copy-on-read. This should be
2799136607SVladimir Sementsov-Ogievskiy * large enough to process multiple clusters in a single call, so
2899136607SVladimir Sementsov-Ogievskiy * that populating contiguous regions of the image is efficient.
294f1043b4SStefan Hajnoczi */
3099136607SVladimir Sementsov-Ogievskiy STREAM_CHUNK = 512 * 1024, /* in bytes */
314f1043b4SStefan Hajnoczi };
324f1043b4SStefan Hajnoczi
334f1043b4SStefan Hajnoczi typedef struct StreamBlockJob {
344f1043b4SStefan Hajnoczi BlockJob common;
35048954e2SVladimir Sementsov-Ogievskiy BlockBackend *blk;
3667acfd21SMax Reitz BlockDriverState *base_overlay; /* COW overlay (stream from this) */
3767acfd21SMax Reitz BlockDriverState *above_base; /* Node directly above the base */
38205736f4SAndrey Shinkevich BlockDriverState *cor_filter_bs;
390f6c9498SVladimir Sementsov-Ogievskiy BlockDriverState *target_bs;
401d809098SPaolo Bonzini BlockdevOnError on_error;
4113d8cc51SJeff Cody char *backing_file_str;
4272098a3aSPeter Krempa bool backing_mask_protocol;
43e7d22f8bSAlberto Garcia bool bs_read_only;
444f1043b4SStefan Hajnoczi } StreamBlockJob;
454f1043b4SStefan Hajnoczi
stream_populate(BlockBackend * blk,int64_t offset,uint64_t bytes)4603e35d82SKevin Wolf static int coroutine_fn stream_populate(BlockBackend *blk,
4799136607SVladimir Sementsov-Ogievskiy int64_t offset, uint64_t bytes)
484f1043b4SStefan Hajnoczi {
498493211cSEric Blake assert(bytes < SIZE_MAX);
504f1043b4SStefan Hajnoczi
51205736f4SAndrey Shinkevich return blk_co_preadv(blk, offset, bytes, NULL, BDRV_REQ_PREFETCH);
5265854933SAlberto Garcia }
5365854933SAlberto Garcia
stream_prepare(Job * job)541b57488aSJohn Snow static int stream_prepare(Job *job)
55f3e69bebSStefan Hajnoczi {
561908a559SKevin Wolf StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
57ad74751fSKevin Wolf BlockDriverState *unfiltered_bs;
58ad74751fSKevin Wolf BlockDriverState *unfiltered_bs_cow;
598d3dd037SHanna Reitz BlockDriverState *base;
608d3dd037SHanna Reitz BlockDriverState *unfiltered_base;
6112fa4af6SKevin Wolf Error *local_err = NULL;
621b57488aSJohn Snow int ret = 0;
63f3e69bebSStefan Hajnoczi
64372b69f5SKevin Wolf GLOBAL_STATE_CODE();
65372b69f5SKevin Wolf
66ad74751fSKevin Wolf bdrv_graph_rdlock_main_loop();
67ad74751fSKevin Wolf unfiltered_bs = bdrv_skip_filters(s->target_bs);
68ad74751fSKevin Wolf unfiltered_bs_cow = bdrv_cow_bs(unfiltered_bs);
69ad74751fSKevin Wolf bdrv_graph_rdunlock_main_loop();
70ad74751fSKevin Wolf
71205736f4SAndrey Shinkevich /* We should drop filter at this point, as filter hold the backing chain */
72205736f4SAndrey Shinkevich bdrv_cor_filter_drop(s->cor_filter_bs);
73205736f4SAndrey Shinkevich s->cor_filter_bs = NULL;
7465854933SAlberto Garcia
7592140b9fSKevin Wolf /*
767d4ca9d2SKevin Wolf * bdrv_set_backing_hd() requires that the unfiltered_bs and the COW child
777d4ca9d2SKevin Wolf * of unfiltered_bs is drained. Drain already here and use
787d4ca9d2SKevin Wolf * bdrv_set_backing_hd_drained() instead because the polling during
797d4ca9d2SKevin Wolf * drained_begin() might change the graph, and if we do this only later, we
807d4ca9d2SKevin Wolf * may end up working with the wrong base node (or it might even have gone
817d4ca9d2SKevin Wolf * away by the time we want to use it).
8292140b9fSKevin Wolf */
8392140b9fSKevin Wolf bdrv_drained_begin(unfiltered_bs);
847d4ca9d2SKevin Wolf if (unfiltered_bs_cow) {
857d4ca9d2SKevin Wolf bdrv_ref(unfiltered_bs_cow);
867d4ca9d2SKevin Wolf bdrv_drained_begin(unfiltered_bs_cow);
877d4ca9d2SKevin Wolf }
88b1e1af39SHanna Reitz
89372b69f5SKevin Wolf bdrv_graph_rdlock_main_loop();
908d3dd037SHanna Reitz base = bdrv_filter_or_cow_bs(s->above_base);
918d3dd037SHanna Reitz unfiltered_base = bdrv_skip_filters(base);
92372b69f5SKevin Wolf bdrv_graph_rdunlock_main_loop();
938d3dd037SHanna Reitz
9478a9c76eSKevin Wolf if (unfiltered_bs_cow) {
95f3e69bebSStefan Hajnoczi const char *base_id = NULL, *base_fmt = NULL;
96000e5a1cSAndrey Shinkevich if (unfiltered_base) {
97000e5a1cSAndrey Shinkevich base_id = s->backing_file_str ?: unfiltered_base->filename;
98000e5a1cSAndrey Shinkevich if (unfiltered_base->drv) {
9972098a3aSPeter Krempa if (s->backing_mask_protocol &&
10072098a3aSPeter Krempa unfiltered_base->drv->protocol_name) {
10172098a3aSPeter Krempa base_fmt = "raw";
10272098a3aSPeter Krempa } else {
103000e5a1cSAndrey Shinkevich base_fmt = unfiltered_base->drv->format_name;
104f3e69bebSStefan Hajnoczi }
105f3e69bebSStefan Hajnoczi }
10672098a3aSPeter Krempa }
107b1e1af39SHanna Reitz
1086bc30f19SStefan Hajnoczi bdrv_graph_wrlock();
10992140b9fSKevin Wolf bdrv_set_backing_hd_drained(unfiltered_bs, base, &local_err);
1106bc30f19SStefan Hajnoczi bdrv_graph_wrunlock();
11192140b9fSKevin Wolf
11292140b9fSKevin Wolf /*
11392140b9fSKevin Wolf * This call will do I/O, so the graph can change again from here on.
11492140b9fSKevin Wolf * We have already completed the graph change, so we are not in danger
11592140b9fSKevin Wolf * of operating on the wrong node any more if this happens.
11692140b9fSKevin Wolf */
11767acfd21SMax Reitz ret = bdrv_change_backing_file(unfiltered_bs, base_id, base_fmt, false);
11812fa4af6SKevin Wolf if (local_err) {
11912fa4af6SKevin Wolf error_report_err(local_err);
120b1e1af39SHanna Reitz ret = -EPERM;
121b1e1af39SHanna Reitz goto out;
12212fa4af6SKevin Wolf }
123f3e69bebSStefan Hajnoczi }
124f3e69bebSStefan Hajnoczi
125b1e1af39SHanna Reitz out:
1267d4ca9d2SKevin Wolf if (unfiltered_bs_cow) {
1277d4ca9d2SKevin Wolf bdrv_drained_end(unfiltered_bs_cow);
1287d4ca9d2SKevin Wolf bdrv_unref(unfiltered_bs_cow);
1297d4ca9d2SKevin Wolf }
13092140b9fSKevin Wolf bdrv_drained_end(unfiltered_bs);
1311b57488aSJohn Snow return ret;
1321b57488aSJohn Snow }
1331b57488aSJohn Snow
stream_clean(Job * job)1341b57488aSJohn Snow static void stream_clean(Job *job)
1351b57488aSJohn Snow {
1361b57488aSJohn Snow StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
1371b57488aSJohn Snow
138205736f4SAndrey Shinkevich if (s->cor_filter_bs) {
139205736f4SAndrey Shinkevich bdrv_cor_filter_drop(s->cor_filter_bs);
140205736f4SAndrey Shinkevich s->cor_filter_bs = NULL;
141205736f4SAndrey Shinkevich }
142205736f4SAndrey Shinkevich
143048954e2SVladimir Sementsov-Ogievskiy blk_unref(s->blk);
144048954e2SVladimir Sementsov-Ogievskiy s->blk = NULL;
145048954e2SVladimir Sementsov-Ogievskiy
14661b49e48SAlberto Garcia /* Reopen the image back in read-only mode if necessary */
147e7d22f8bSAlberto Garcia if (s->bs_read_only) {
148a170a91fSKevin Wolf /* Give up write permissions before making it read-only */
1490f6c9498SVladimir Sementsov-Ogievskiy bdrv_reopen_set_read_only(s->target_bs, true, NULL);
15061b49e48SAlberto Garcia }
15161b49e48SAlberto Garcia
152f3e69bebSStefan Hajnoczi g_free(s->backing_file_str);
153f3e69bebSStefan Hajnoczi }
154f3e69bebSStefan Hajnoczi
stream_run(Job * job,Error ** errp)155f67432a2SJohn Snow static int coroutine_fn stream_run(Job *job, Error **errp)
1564f1043b4SStefan Hajnoczi {
157f67432a2SJohn Snow StreamBlockJob *s = container_of(job, StreamBlockJob, common.job);
158ad74751fSKevin Wolf BlockDriverState *unfiltered_bs;
15905df8a6aSKevin Wolf int64_t len;
160d535435fSEric Blake int64_t offset = 0;
1611d809098SPaolo Bonzini int error = 0;
16251b0a488SEric Blake int64_t n = 0; /* bytes */
1634f1043b4SStefan Hajnoczi
164ad74751fSKevin Wolf WITH_GRAPH_RDLOCK_GUARD() {
165ad74751fSKevin Wolf unfiltered_bs = bdrv_skip_filters(s->target_bs);
16667acfd21SMax Reitz if (unfiltered_bs == s->base_overlay) {
167c624b015SAndrey Shinkevich /* Nothing to stream */
16896a07d5bSAndrey Shinkevich return 0;
169f4a193e7SMax Reitz }
170f4a193e7SMax Reitz
1718ab8140aSKevin Wolf len = bdrv_co_getlength(s->target_bs);
17205df8a6aSKevin Wolf if (len < 0) {
17396a07d5bSAndrey Shinkevich return len;
1744f1043b4SStefan Hajnoczi }
1758ab8140aSKevin Wolf }
17630a5c887SKevin Wolf job_progress_set_remaining(&s->common.job, len);
1774f1043b4SStefan Hajnoczi
17805df8a6aSKevin Wolf for ( ; offset < len; offset += n) {
179f9749f28SPaolo Bonzini bool copy;
18035c94535SChen Qun int ret;
1814513eafeSPaolo Bonzini
1824513eafeSPaolo Bonzini /* Note that even when no rate limit is applied we need to yield
183c57b6656SKevin Wolf * with no pending I/O here so that bdrv_drain_all() returns.
1844513eafeSPaolo Bonzini */
185018e5987SKevin Wolf block_job_ratelimit_sleep(&s->common);
186daa7f2f9SKevin Wolf if (job_is_cancelled(&s->common.job)) {
1874f1043b4SStefan Hajnoczi break;
1884f1043b4SStefan Hajnoczi }
1894f1043b4SStefan Hajnoczi
190c3e4f43aSStefan Weil copy = false;
191c3e4f43aSStefan Weil
1927ff9579eSKevin Wolf WITH_GRAPH_RDLOCK_GUARD() {
193cc323997SPaolo Bonzini ret = bdrv_co_is_allocated(unfiltered_bs, offset, STREAM_CHUNK, &n);
194f9749f28SPaolo Bonzini if (ret == 1) {
195f9749f28SPaolo Bonzini /* Allocated in the top, no need to copy. */
196d663640cSPaolo Bonzini } else if (ret >= 0) {
1977ff9579eSKevin Wolf /*
1987ff9579eSKevin Wolf * Copy if allocated in the intermediate images. Limit to the
1997ff9579eSKevin Wolf * known-unallocated area [offset, offset+n*BDRV_SECTOR_SIZE).
2007ff9579eSKevin Wolf */
201cc323997SPaolo Bonzini ret = bdrv_co_is_allocated_above(bdrv_cow_bs(unfiltered_bs),
20267acfd21SMax Reitz s->base_overlay, true,
20351b0a488SEric Blake offset, n, &n);
204571cd9dcSStefan Hajnoczi /* Finish early if end of backing file has been reached */
205571cd9dcSStefan Hajnoczi if (ret == 0 && n == 0) {
20605df8a6aSKevin Wolf n = len - offset;
207571cd9dcSStefan Hajnoczi }
208571cd9dcSStefan Hajnoczi
209a92b1b06SEric Blake copy = (ret > 0);
210f9749f28SPaolo Bonzini }
2117ff9579eSKevin Wolf }
21251b0a488SEric Blake trace_stream_one_iteration(s, offset, n, ret);
213c3e4f43aSStefan Weil if (copy) {
214048954e2SVladimir Sementsov-Ogievskiy ret = stream_populate(s->blk, offset, n);
2154f1043b4SStefan Hajnoczi }
2164f1043b4SStefan Hajnoczi if (ret < 0) {
2171d809098SPaolo Bonzini BlockErrorAction action =
21881e254dcSKevin Wolf block_job_error_action(&s->common, s->on_error, true, -ret);
219a589569fSWenchao Xia if (action == BLOCK_ERROR_ACTION_STOP) {
2201d809098SPaolo Bonzini n = 0;
2211d809098SPaolo Bonzini continue;
2221d809098SPaolo Bonzini }
2231d809098SPaolo Bonzini if (error == 0) {
2241d809098SPaolo Bonzini error = ret;
2251d809098SPaolo Bonzini }
226a589569fSWenchao Xia if (action == BLOCK_ERROR_ACTION_REPORT) {
2274f1043b4SStefan Hajnoczi break;
2284f1043b4SStefan Hajnoczi }
2291d809098SPaolo Bonzini }
2304f1043b4SStefan Hajnoczi
2314f1043b4SStefan Hajnoczi /* Publish progress */
23230a5c887SKevin Wolf job_progress_update(&s->common.job, n);
233dee81d51SKevin Wolf if (copy) {
234018e5987SKevin Wolf block_job_ratelimit_processed_bytes(&s->common, n);
235f14a39ccSSascha Silbe }
2364f1043b4SStefan Hajnoczi }
2374f1043b4SStefan Hajnoczi
23896a07d5bSAndrey Shinkevich /* Do not remove the backing file if an error was there but ignored. */
23996a07d5bSAndrey Shinkevich return error;
2404f1043b4SStefan Hajnoczi }
2414f1043b4SStefan Hajnoczi
2423fc4b10aSFam Zheng static const BlockJobDriver stream_job_driver = {
24333e9e9bdSKevin Wolf .job_driver = {
2444f1043b4SStefan Hajnoczi .instance_size = sizeof(StreamBlockJob),
2458e4c8700SKevin Wolf .job_type = JOB_TYPE_STREAM,
24680fa2c75SKevin Wolf .free = block_job_free,
247f67432a2SJohn Snow .run = stream_run,
2481b57488aSJohn Snow .prepare = stream_prepare,
2491b57488aSJohn Snow .clean = stream_clean,
250b15de828SKevin Wolf .user_resume = block_job_user_resume,
251da01ff7fSKevin Wolf },
2524f1043b4SStefan Hajnoczi };
2534f1043b4SStefan Hajnoczi
stream_start(const char * job_id,BlockDriverState * bs,BlockDriverState * base,const char * backing_file_str,bool backing_mask_protocol,BlockDriverState * bottom,int creation_flags,int64_t speed,BlockdevOnError on_error,const char * filter_node_name,Error ** errp)2542323322eSAlberto Garcia void stream_start(const char *job_id, BlockDriverState *bs,
2552323322eSAlberto Garcia BlockDriverState *base, const char *backing_file_str,
25672098a3aSPeter Krempa bool backing_mask_protocol,
2577f4a396dSVladimir Sementsov-Ogievskiy BlockDriverState *bottom,
258cf6320dfSJohn Snow int creation_flags, int64_t speed,
259880747a8SAndrey Shinkevich BlockdevOnError on_error,
260880747a8SAndrey Shinkevich const char *filter_node_name,
261880747a8SAndrey Shinkevich Error **errp)
2624f1043b4SStefan Hajnoczi {
2631bf26076SKevin Wolf StreamBlockJob *s = NULL;
26461b49e48SAlberto Garcia BlockDriverState *iter;
265e7d22f8bSAlberto Garcia bool bs_read_only;
266c624b015SAndrey Shinkevich int basic_flags = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED;
2677f4a396dSVladimir Sementsov-Ogievskiy BlockDriverState *base_overlay;
268205736f4SAndrey Shinkevich BlockDriverState *cor_filter_bs = NULL;
26967acfd21SMax Reitz BlockDriverState *above_base;
270205736f4SAndrey Shinkevich QDict *opts;
2711bf26076SKevin Wolf int ret;
2724f1043b4SStefan Hajnoczi
273b4ad82aaSEmanuele Giuseppe Esposito GLOBAL_STATE_CODE();
274b4ad82aaSEmanuele Giuseppe Esposito
2757f4a396dSVladimir Sementsov-Ogievskiy assert(!(base && bottom));
2767f4a396dSVladimir Sementsov-Ogievskiy assert(!(backing_file_str && bottom));
2777f4a396dSVladimir Sementsov-Ogievskiy
2789275fc72SKevin Wolf bdrv_graph_rdlock_main_loop();
2799275fc72SKevin Wolf
2807f4a396dSVladimir Sementsov-Ogievskiy if (bottom) {
2817f4a396dSVladimir Sementsov-Ogievskiy /*
2827f4a396dSVladimir Sementsov-Ogievskiy * New simple interface. The code is written in terms of old interface
2837f4a396dSVladimir Sementsov-Ogievskiy * with @base parameter (still, it doesn't freeze link to base, so in
2847f4a396dSVladimir Sementsov-Ogievskiy * this mean old code is correct for new interface). So, for now, just
2857f4a396dSVladimir Sementsov-Ogievskiy * emulate base_overlay and above_base. Still, when old interface
2867f4a396dSVladimir Sementsov-Ogievskiy * finally removed, we should refactor code to use only "bottom", but
2877f4a396dSVladimir Sementsov-Ogievskiy * not "*base*" things.
2887f4a396dSVladimir Sementsov-Ogievskiy */
2897f4a396dSVladimir Sementsov-Ogievskiy assert(!bottom->drv->is_filter);
2907f4a396dSVladimir Sementsov-Ogievskiy base_overlay = above_base = bottom;
2917f4a396dSVladimir Sementsov-Ogievskiy } else {
2927f4a396dSVladimir Sementsov-Ogievskiy base_overlay = bdrv_find_overlay(bs, base);
29367acfd21SMax Reitz if (!base_overlay) {
29467acfd21SMax Reitz error_setg(errp, "'%s' is not in the backing chain of '%s'",
29567acfd21SMax Reitz base->node_name, bs->node_name);
2969275fc72SKevin Wolf goto out_rdlock;
29767acfd21SMax Reitz }
29867acfd21SMax Reitz
29967acfd21SMax Reitz /*
3007f4a396dSVladimir Sementsov-Ogievskiy * Find the node directly above @base. @base_overlay is a COW overlay,
3017f4a396dSVladimir Sementsov-Ogievskiy * so it must have a bdrv_cow_child(), but it is the immediate overlay
3027f4a396dSVladimir Sementsov-Ogievskiy * of @base, so between the two there can only be filters.
30367acfd21SMax Reitz */
30467acfd21SMax Reitz above_base = base_overlay;
30567acfd21SMax Reitz if (bdrv_cow_bs(above_base) != base) {
30667acfd21SMax Reitz above_base = bdrv_cow_bs(above_base);
30767acfd21SMax Reitz while (bdrv_filter_bs(above_base) != base) {
30867acfd21SMax Reitz above_base = bdrv_filter_bs(above_base);
30967acfd21SMax Reitz }
31067acfd21SMax Reitz }
3117f4a396dSVladimir Sementsov-Ogievskiy }
31267acfd21SMax Reitz
313205736f4SAndrey Shinkevich /* Make sure that the image is opened in read-write mode */
314205736f4SAndrey Shinkevich bs_read_only = bdrv_is_read_only(bs);
315205736f4SAndrey Shinkevich if (bs_read_only) {
316205736f4SAndrey Shinkevich /* Hold the chain during reopen */
31767acfd21SMax Reitz if (bdrv_freeze_backing_chain(bs, above_base, errp) < 0) {
3189275fc72SKevin Wolf goto out_rdlock;
31920509c4bSAlberto Garcia }
32020509c4bSAlberto Garcia
321205736f4SAndrey Shinkevich ret = bdrv_reopen_set_read_only(bs, false, errp);
322205736f4SAndrey Shinkevich
323205736f4SAndrey Shinkevich /* failure, or cor-filter will hold the chain */
324205736f4SAndrey Shinkevich bdrv_unfreeze_backing_chain(bs, above_base);
325205736f4SAndrey Shinkevich
326205736f4SAndrey Shinkevich if (ret < 0) {
3279275fc72SKevin Wolf goto out_rdlock;
32861b49e48SAlberto Garcia }
32961b49e48SAlberto Garcia }
33061b49e48SAlberto Garcia
3319275fc72SKevin Wolf bdrv_graph_rdunlock_main_loop();
3329275fc72SKevin Wolf
333205736f4SAndrey Shinkevich opts = qdict_new();
334205736f4SAndrey Shinkevich
335205736f4SAndrey Shinkevich qdict_put_str(opts, "driver", "copy-on-read");
336205736f4SAndrey Shinkevich qdict_put_str(opts, "file", bdrv_get_node_name(bs));
337205736f4SAndrey Shinkevich /* Pass the base_overlay node name as 'bottom' to COR driver */
338205736f4SAndrey Shinkevich qdict_put_str(opts, "bottom", base_overlay->node_name);
339205736f4SAndrey Shinkevich if (filter_node_name) {
340205736f4SAndrey Shinkevich qdict_put_str(opts, "node-name", filter_node_name);
341205736f4SAndrey Shinkevich }
342205736f4SAndrey Shinkevich
343205736f4SAndrey Shinkevich cor_filter_bs = bdrv_insert_node(bs, opts, BDRV_O_RDWR, errp);
344205736f4SAndrey Shinkevich if (!cor_filter_bs) {
345205736f4SAndrey Shinkevich goto fail;
346205736f4SAndrey Shinkevich }
347205736f4SAndrey Shinkevich
348205736f4SAndrey Shinkevich if (!filter_node_name) {
349205736f4SAndrey Shinkevich cor_filter_bs->implicit = true;
350205736f4SAndrey Shinkevich }
351205736f4SAndrey Shinkevich
352205736f4SAndrey Shinkevich s = block_job_create(job_id, &stream_job_driver, NULL, cor_filter_bs,
353048954e2SVladimir Sementsov-Ogievskiy 0, BLK_PERM_ALL,
354cf6320dfSJohn Snow speed, creation_flags, NULL, NULL, errp);
355a170a91fSKevin Wolf if (!s) {
356a170a91fSKevin Wolf goto fail;
357a170a91fSKevin Wolf }
358a170a91fSKevin Wolf
359048954e2SVladimir Sementsov-Ogievskiy s->blk = blk_new_with_bs(cor_filter_bs, BLK_PERM_CONSISTENT_READ,
360048954e2SVladimir Sementsov-Ogievskiy basic_flags | BLK_PERM_WRITE, errp);
361048954e2SVladimir Sementsov-Ogievskiy if (!s->blk) {
362048954e2SVladimir Sementsov-Ogievskiy goto fail;
363048954e2SVladimir Sementsov-Ogievskiy }
364048954e2SVladimir Sementsov-Ogievskiy /*
365048954e2SVladimir Sementsov-Ogievskiy * Disable request queuing in the BlockBackend to avoid deadlocks on drain:
366048954e2SVladimir Sementsov-Ogievskiy * The job reports that it's busy until it reaches a pause point.
367048954e2SVladimir Sementsov-Ogievskiy */
368048954e2SVladimir Sementsov-Ogievskiy blk_set_disable_request_queuing(s->blk, true);
369048954e2SVladimir Sementsov-Ogievskiy blk_set_allow_aio_context_change(s->blk, true);
370048954e2SVladimir Sementsov-Ogievskiy
371205736f4SAndrey Shinkevich /*
372205736f4SAndrey Shinkevich * Prevent concurrent jobs trying to modify the graph structure here, we
373205736f4SAndrey Shinkevich * already have our own plans. Also don't allow resize as the image size is
374205736f4SAndrey Shinkevich * queried only at the job start and then cached.
375205736f4SAndrey Shinkevich */
3766bc30f19SStefan Hajnoczi bdrv_graph_wrlock();
377205736f4SAndrey Shinkevich if (block_job_add_bdrv(&s->common, "active node", bs, 0,
3781bf26076SKevin Wolf basic_flags | BLK_PERM_WRITE, errp)) {
3796bc30f19SStefan Hajnoczi bdrv_graph_wrunlock();
380205736f4SAndrey Shinkevich goto fail;
381205736f4SAndrey Shinkevich }
382205736f4SAndrey Shinkevich
383a170a91fSKevin Wolf /* Block all intermediate nodes between bs and base, because they will
384a170a91fSKevin Wolf * disappear from the chain after this operation. The streaming job reads
385c624b015SAndrey Shinkevich * every block only once, assuming that it doesn't change, so forbid writes
386c624b015SAndrey Shinkevich * and resizes. Reassign the base node pointer because the backing BS of the
387c624b015SAndrey Shinkevich * bottom node might change after the call to bdrv_reopen_set_read_only()
388c624b015SAndrey Shinkevich * due to parallel block jobs running.
38967acfd21SMax Reitz * above_base node might change after the call to
39067acfd21SMax Reitz * bdrv_reopen_set_read_only() due to parallel block jobs running.
391c624b015SAndrey Shinkevich */
39267acfd21SMax Reitz base = bdrv_filter_or_cow_bs(above_base);
39367acfd21SMax Reitz for (iter = bdrv_filter_or_cow_bs(bs); iter != base;
39467acfd21SMax Reitz iter = bdrv_filter_or_cow_bs(iter))
39567acfd21SMax Reitz {
3961bf26076SKevin Wolf ret = block_job_add_bdrv(&s->common, "intermediate node", iter, 0,
3971bf26076SKevin Wolf basic_flags, errp);
3981bf26076SKevin Wolf if (ret < 0) {
3996bc30f19SStefan Hajnoczi bdrv_graph_wrunlock();
4001bf26076SKevin Wolf goto fail;
4011bf26076SKevin Wolf }
40261b49e48SAlberto Garcia }
4036bc30f19SStefan Hajnoczi bdrv_graph_wrunlock();
40461b49e48SAlberto Garcia
40567acfd21SMax Reitz s->base_overlay = base_overlay;
40667acfd21SMax Reitz s->above_base = above_base;
40713d8cc51SJeff Cody s->backing_file_str = g_strdup(backing_file_str);
40872098a3aSPeter Krempa s->backing_mask_protocol = backing_mask_protocol;
409205736f4SAndrey Shinkevich s->cor_filter_bs = cor_filter_bs;
4100f6c9498SVladimir Sementsov-Ogievskiy s->target_bs = bs;
411e7d22f8bSAlberto Garcia s->bs_read_only = bs_read_only;
4124f1043b4SStefan Hajnoczi
4131d809098SPaolo Bonzini s->on_error = on_error;
4145ccac6f1SJohn Snow trace_stream_start(bs, base, s);
415da01ff7fSKevin Wolf job_start(&s->common.job);
416a170a91fSKevin Wolf return;
417a170a91fSKevin Wolf
418a170a91fSKevin Wolf fail:
4191bf26076SKevin Wolf if (s) {
4201bf26076SKevin Wolf job_early_fail(&s->common.job);
4211bf26076SKevin Wolf }
422205736f4SAndrey Shinkevich if (cor_filter_bs) {
423205736f4SAndrey Shinkevich bdrv_cor_filter_drop(cor_filter_bs);
424205736f4SAndrey Shinkevich }
425e7d22f8bSAlberto Garcia if (bs_read_only) {
426e7d22f8bSAlberto Garcia bdrv_reopen_set_read_only(bs, true, NULL);
427a170a91fSKevin Wolf }
4289275fc72SKevin Wolf return;
4299275fc72SKevin Wolf
4309275fc72SKevin Wolf out_rdlock:
4319275fc72SKevin Wolf bdrv_graph_rdunlock_main_loop();
4324f1043b4SStefan Hajnoczi }
433