10  * See the COPYING.LIB file in the top-level directory.
16 #include "block/block_int.h"
17 #include "block/blockjob_int.h"
21 #include "sysemu/block-backend.h"
22 #include "block/copy-on-read.h"
26      * Maximum chunk size to feed to copy-on-read.  This should be
67     unfiltered_bs = bdrv_skip_filters(s->target_bs);  in stream_prepare()
72     bdrv_cor_filter_drop(s->cor_filter_bs);  in stream_prepare()
73     s->cor_filter_bs = NULL;  in stream_prepare()
90     base = bdrv_filter_or_cow_bs(s->above_base);  in stream_prepare()
97             base_id = s->backing_file_str ?: unfiltered_base->filename;  in stream_prepare()
98             if (unfiltered_base->drv) {  in stream_prepare()
99                 if (s->backing_mask_protocol &&  in stream_prepare()
100                     unfiltered_base->drv->protocol_name) {  in stream_prepare()
103                     base_fmt = unfiltered_base->drv->format_name;  in stream_prepare()
120             ret = -EPERM;  in stream_prepare()
138     if (s->cor_filter_bs) {  in stream_clean()
139         bdrv_cor_filter_drop(s->cor_filter_bs);  in stream_clean()
140         s->cor_filter_bs = NULL;  in stream_clean()
143     blk_unref(s->blk);  in stream_clean()
144     s->blk = NULL;  in stream_clean()
146     /* Reopen the image back in read-only mode if necessary */  in stream_clean()
147     if (s->bs_read_only) {  in stream_clean()
148         /* Give up write permissions before making it read-only */  in stream_clean()
149         bdrv_reopen_set_read_only(s->target_bs, true, NULL);  in stream_clean()
152     g_free(s->backing_file_str);  in stream_clean()
159     int64_t len = -1;  in stream_run()
165         unfiltered_bs = bdrv_skip_filters(s->target_bs);  in stream_run()
166         if (unfiltered_bs == s->base_overlay) {  in stream_run()
171         len = bdrv_co_getlength(s->target_bs);  in stream_run()
176     job_progress_set_remaining(&s->common.job, len);  in stream_run()
179         bool copy;  in stream_run()  local
180         int ret = -1;  in stream_run()
185         block_job_ratelimit_sleep(&s->common);  in stream_run()
186         if (job_is_cancelled(&s->common.job)) {  in stream_run()
190         copy = false;  in stream_run()
195                 /* Allocated in the top, no need to copy.  */  in stream_run()
198                  * Copy if allocated in the intermediate images.  Limit to the  in stream_run()
199                  * known-unallocated area [offset, offset+n*BDRV_SECTOR_SIZE).  in stream_run()
202                                                  s->base_overlay, true,  in stream_run()
206                     n = len - offset;  in stream_run()
209                 copy = (ret > 0);  in stream_run()
213         if (copy) {  in stream_run()
214             ret = stream_populate(s->blk, offset, n);  in stream_run()
218                 block_job_error_action(&s->common, s->on_error, true, -ret);  in stream_run()
232         job_progress_update(&s->common.job, n);  in stream_run()
233         if (copy) {  in stream_run()
234             block_job_ratelimit_processed_bytes(&s->common, n);  in stream_run()
289         assert(!bottom->drv->is_filter);  in stream_start()
295                        base->node_name, bs->node_name);  in stream_start()
313     /* Make sure that the image is opened in read-write mode */  in stream_start()
323         /* failure, or cor-filter will hold the chain */  in stream_start()
335     qdict_put_str(opts, "driver", "copy-on-read");  in stream_start()
338     qdict_put_str(opts, "bottom", base_overlay->node_name);  in stream_start()
340         qdict_put_str(opts, "node-name", filter_node_name);  in stream_start()
349         cor_filter_bs->implicit = true;  in stream_start()
359     s->blk = blk_new_with_bs(cor_filter_bs, BLK_PERM_CONSISTENT_READ,  in stream_start()
361     if (!s->blk) {  in stream_start()
368     blk_set_disable_request_queuing(s->blk, true);  in stream_start()
369     blk_set_allow_aio_context_change(s->blk, true);  in stream_start()
377     if (block_job_add_bdrv(&s->common, "active node", bs, 0,  in stream_start()
383     /* Block all intermediate nodes between bs and base, because they will  in stream_start()
385      * every block only once, assuming that it doesn't change, so forbid writes  in stream_start()
388      * due to parallel block jobs running.  in stream_start()
390      * bdrv_reopen_set_read_only() due to parallel block jobs running.  in stream_start()
396         ret = block_job_add_bdrv(&s->common, "intermediate node", iter, 0,  in stream_start()
405     s->base_overlay = base_overlay;  in stream_start()
406     s->above_base = above_base;  in stream_start()
407     s->backing_file_str = g_strdup(backing_file_str);  in stream_start()
408     s->backing_mask_protocol = backing_mask_protocol;  in stream_start()
409     s->cor_filter_bs = cor_filter_bs;  in stream_start()
410     s->target_bs = bs;  in stream_start()
411     s->bs_read_only = bs_read_only;  in stream_start()
413     s->on_error = on_error;  in stream_start()
415     job_start(&s->common.job);  in stream_start()
420         job_early_fail(&s->common.job);  in stream_start()