diff options
| -rw-r--r-- | block/backup.c | 105 | ||||
| -rw-r--r-- | blockdev.c | 29 | ||||
| -rw-r--r-- | include/block/block_int.h | 4 | ||||
| -rw-r--r-- | qmp-commands.hx | 1 |
4 files changed, 101 insertions, 38 deletions
diff --git a/block/backup.c b/block/backup.c index 16105d40b1..6ae8a05a3e 100644 --- a/block/backup.c +++ b/block/backup.c @@ -37,6 +37,7 @@ typedef struct CowRequest { typedef struct BackupBlockJob { BlockJob common; BlockDriverState *target; + MirrorSyncMode sync_mode; RateLimit limit; BlockdevOnError on_source_error; BlockdevOnError on_target_error; @@ -247,40 +248,83 @@ static void coroutine_fn backup_run(void *opaque) bdrv_add_before_write_notifier(bs, &before_write); - for (; start < end; start++) { - bool error_is_read; - - if (block_job_is_cancelled(&job->common)) { - break; + if (job->sync_mode == MIRROR_SYNC_MODE_NONE) { + while (!block_job_is_cancelled(&job->common)) { + /* Yield until the job is cancelled. We just let our before_write + * notify callback service CoW requests. */ + job->common.busy = false; + qemu_coroutine_yield(); + job->common.busy = true; } + } else { + /* Both FULL and TOP SYNC_MODE's require copying.. */ + for (; start < end; start++) { + bool error_is_read; - /* we need to yield so that qemu_aio_flush() returns. - * (without, VM does not reboot) - */ - if (job->common.speed) { - uint64_t delay_ns = ratelimit_calculate_delay( - &job->limit, job->sectors_read); - job->sectors_read = 0; - block_job_sleep_ns(&job->common, rt_clock, delay_ns); - } else { - block_job_sleep_ns(&job->common, rt_clock, 0); - } + if (block_job_is_cancelled(&job->common)) { + break; + } - if (block_job_is_cancelled(&job->common)) { - break; - } + /* we need to yield so that qemu_aio_flush() returns. + * (without, VM does not reboot) + */ + if (job->common.speed) { + uint64_t delay_ns = ratelimit_calculate_delay( + &job->limit, job->sectors_read); + job->sectors_read = 0; + block_job_sleep_ns(&job->common, rt_clock, delay_ns); + } else { + block_job_sleep_ns(&job->common, rt_clock, 0); + } - ret = backup_do_cow(bs, start * BACKUP_SECTORS_PER_CLUSTER, - BACKUP_SECTORS_PER_CLUSTER, &error_is_read); - if (ret < 0) { - /* Depending on error action, fail now or retry cluster */ - BlockErrorAction action = - backup_error_action(job, error_is_read, -ret); - if (action == BDRV_ACTION_REPORT) { + if (block_job_is_cancelled(&job->common)) { break; - } else { - start--; - continue; + } + + if (job->sync_mode == MIRROR_SYNC_MODE_TOP) { + int i, n; + int alloced = 0; + + /* Check to see if these blocks are already in the + * backing file. */ + + for (i = 0; i < BACKUP_SECTORS_PER_CLUSTER;) { + /* bdrv_co_is_allocated() only returns true/false based + * on the first set of sectors it comes accross that + * are are all in the same state. + * For that reason we must verify each sector in the + * backup cluster length. We end up copying more than + * needed but at some point that is always the case. */ + alloced = + bdrv_co_is_allocated(bs, + start * BACKUP_SECTORS_PER_CLUSTER + i, + BACKUP_SECTORS_PER_CLUSTER - i, &n); + i += n; + + if (alloced == 1) { + break; + } + } + + /* If the above loop never found any sectors that are in + * the topmost image, skip this backup. */ + if (alloced == 0) { + continue; + } + } + /* FULL sync mode we copy the whole drive. */ + ret = backup_do_cow(bs, start * BACKUP_SECTORS_PER_CLUSTER, + BACKUP_SECTORS_PER_CLUSTER, &error_is_read); + if (ret < 0) { + /* Depending on error action, fail now or retry cluster */ + BlockErrorAction action = + backup_error_action(job, error_is_read, -ret); + if (action == BDRV_ACTION_REPORT) { + break; + } else { + start--; + continue; + } } } } @@ -300,7 +344,7 @@ static void coroutine_fn backup_run(void *opaque) } void backup_start(BlockDriverState *bs, BlockDriverState *target, - int64_t speed, + int64_t speed, MirrorSyncMode sync_mode, BlockdevOnError on_source_error, BlockdevOnError on_target_error, BlockDriverCompletionFunc *cb, void *opaque, @@ -335,6 +379,7 @@ void backup_start(BlockDriverState *bs, BlockDriverState *target, job->on_source_error = on_source_error; job->on_target_error = on_target_error; job->target = target; + job->sync_mode = sync_mode; job->common.len = len; job->common.co = qemu_coroutine_create(backup_run); qemu_coroutine_enter(job->common.co, job); diff --git a/blockdev.c b/blockdev.c index ef55b1a15c..4534864802 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1489,16 +1489,13 @@ void qmp_drive_backup(const char *device, const char *target, { BlockDriverState *bs; BlockDriverState *target_bs; + BlockDriverState *source = NULL; BlockDriver *drv = NULL; Error *local_err = NULL; int flags; int64_t size; int ret; - if (sync != MIRROR_SYNC_MODE_FULL) { - error_setg(errp, "only sync mode 'full' is currently supported"); - return; - } if (!has_speed) { speed = 0; } @@ -1541,6 +1538,18 @@ void qmp_drive_backup(const char *device, const char *target, flags = bs->open_flags | BDRV_O_RDWR; + /* See if we have a backing HD we can use to create our new image + * on top of. */ + if (sync == MIRROR_SYNC_MODE_TOP) { + source = bs->backing_hd; + if (!source) { + sync = MIRROR_SYNC_MODE_FULL; + } + } + if (sync == MIRROR_SYNC_MODE_NONE) { + source = bs; + } + size = bdrv_getlength(bs); if (size < 0) { error_setg_errno(errp, -size, "bdrv_getlength failed"); @@ -1549,8 +1558,14 @@ void qmp_drive_backup(const char *device, const char *target, if (mode != NEW_IMAGE_MODE_EXISTING) { assert(format && drv); - bdrv_img_create(target, format, - NULL, NULL, NULL, size, flags, &local_err, false); + if (source) { + bdrv_img_create(target, format, source->filename, + source->drv->format_name, NULL, + size, flags, &local_err, false); + } else { + bdrv_img_create(target, format, NULL, NULL, NULL, + size, flags, &local_err, false); + } } if (error_is_set(&local_err)) { @@ -1566,7 +1581,7 @@ void qmp_drive_backup(const char *device, const char *target, return; } - backup_start(bs, target_bs, speed, on_source_error, on_target_error, + backup_start(bs, target_bs, speed, sync, on_source_error, on_target_error, block_job_cb, bs, &local_err); if (local_err != NULL) { bdrv_delete(target_bs); diff --git a/include/block/block_int.h b/include/block/block_int.h index c6ac871e21..e45f2a0d56 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -404,6 +404,7 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target, * @bs: Block device to operate on. * @target: Block device to write to. * @speed: The maximum speed, in bytes per second, or 0 for unlimited. + * @sync_mode: What parts of the disk image should be copied to the destination. * @on_source_error: The action to take upon error reading from the source. * @on_target_error: The action to take upon error writing to the target. * @cb: Completion function for the job. @@ -413,7 +414,8 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target, * until the job is cancelled or manually completed. */ void backup_start(BlockDriverState *bs, BlockDriverState *target, - int64_t speed, BlockdevOnError on_source_error, + int64_t speed, MirrorSyncMode sync_mode, + BlockdevOnError on_source_error, BlockdevOnError on_target_error, BlockDriverCompletionFunc *cb, void *opaque, Error **errp); diff --git a/qmp-commands.hx b/qmp-commands.hx index 65a9e26423..2e59b0d218 100644 --- a/qmp-commands.hx +++ b/qmp-commands.hx @@ -960,6 +960,7 @@ Arguments: Example: -> { "execute": "drive-backup", "arguments": { "device": "drive0", + "sync": "full", "target": "backup.img" } } <- { "return": {} } EQMP |