diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 152 |
1 files changed, 119 insertions, 33 deletions
diff --git a/block.c b/block.c index 40c5e1aa73..a517d72d71 100644 --- a/block.c +++ b/block.c @@ -335,6 +335,7 @@ void bdrv_register(BlockDriver *bdrv) BlockDriverState *bdrv_new(const char *device_name, Error **errp) { BlockDriverState *bs; + int i; if (bdrv_find(device_name)) { error_setg(errp, "Device with id '%s' already exists", @@ -353,6 +354,9 @@ BlockDriverState *bdrv_new(const char *device_name, Error **errp) if (device_name[0] != '\0') { QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list); } + for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { + QLIST_INIT(&bs->op_blockers[i]); + } bdrv_iostatus_disable(bs); notifier_list_init(&bs->close_notifiers); notifier_with_return_list_init(&bs->before_write_notifiers); @@ -1090,6 +1094,37 @@ fail: return ret; } +void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) +{ + + if (bs->backing_hd) { + assert(bs->backing_blocker); + bdrv_op_unblock_all(bs->backing_hd, bs->backing_blocker); + } else if (backing_hd) { + error_setg(&bs->backing_blocker, + "device is used as backing hd of '%s'", + bs->device_name); + } + + bs->backing_hd = backing_hd; + if (!backing_hd) { + error_free(bs->backing_blocker); + bs->backing_blocker = NULL; + goto out; + } + bs->open_flags &= ~BDRV_O_NO_BACKING; + pstrcpy(bs->backing_file, sizeof(bs->backing_file), backing_hd->filename); + pstrcpy(bs->backing_format, sizeof(bs->backing_format), + backing_hd->drv ? backing_hd->drv->format_name : ""); + + bdrv_op_block_all(bs->backing_hd, bs->backing_blocker); + /* Otherwise we won't be able to commit due to check in bdrv_commit */ + bdrv_op_unblock(bs->backing_hd, BLOCK_OP_TYPE_COMMIT, + bs->backing_blocker); +out: + bdrv_refresh_limits(bs); +} + /* * Opens the backing file for a BlockDriverState if not yet open * @@ -1103,6 +1138,7 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) char *backing_filename = g_malloc0(PATH_MAX); int ret = 0; BlockDriver *back_drv = NULL; + BlockDriverState *backing_hd; Error *local_err = NULL; if (bs->backing_hd != NULL) { @@ -1125,30 +1161,26 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) bdrv_get_full_backing_filename(bs, backing_filename, PATH_MAX); } + backing_hd = bdrv_new("", errp); + if (bs->backing_format[0] != '\0') { back_drv = bdrv_find_format(bs->backing_format); } assert(bs->backing_hd == NULL); - ret = bdrv_open(&bs->backing_hd, + ret = bdrv_open(&backing_hd, *backing_filename ? backing_filename : NULL, NULL, options, bdrv_backing_flags(bs->open_flags), back_drv, &local_err); if (ret < 0) { - bs->backing_hd = NULL; + bdrv_unref(backing_hd); + backing_hd = NULL; bs->open_flags |= BDRV_O_NO_BACKING; error_setg(errp, "Could not open backing file: %s", error_get_pretty(local_err)); error_free(local_err); goto free_exit; } - - if (bs->backing_hd->file) { - pstrcpy(bs->backing_file, sizeof(bs->backing_file), - bs->backing_hd->file->filename); - } - - /* Recalculate the BlockLimits with the backing file */ - bdrv_refresh_limits(bs); + bdrv_set_backing_hd(bs, backing_hd); free_exit: g_free(backing_filename); @@ -1784,8 +1816,9 @@ void bdrv_close(BlockDriverState *bs) if (bs->drv) { if (bs->backing_hd) { - bdrv_unref(bs->backing_hd); - bs->backing_hd = NULL; + BlockDriverState *backing_hd = bs->backing_hd; + bdrv_set_backing_hd(bs, NULL); + bdrv_unref(backing_hd); } bs->drv->bdrv_close(bs); g_free(bs->opaque); @@ -1945,13 +1978,14 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest, bs_dest->refcnt = bs_src->refcnt; /* job */ - bs_dest->in_use = bs_src->in_use; bs_dest->job = bs_src->job; /* keep the same entry in bdrv_states */ pstrcpy(bs_dest->device_name, sizeof(bs_dest->device_name), bs_src->device_name); bs_dest->device_list = bs_src->device_list; + memcpy(bs_dest->op_blockers, bs_src->op_blockers, + sizeof(bs_dest->op_blockers)); } /* @@ -1986,7 +2020,6 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) assert(QLIST_EMPTY(&bs_new->dirty_bitmaps)); assert(bs_new->job == NULL); assert(bs_new->dev == NULL); - assert(bs_new->in_use == 0); assert(bs_new->io_limits_enabled == false); assert(!throttle_have_timer(&bs_new->throttle_state)); @@ -2005,7 +2038,6 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) /* Check a few fields that should remain attached to the device */ assert(bs_new->dev == NULL); assert(bs_new->job == NULL); - assert(bs_new->in_use == 0); assert(bs_new->io_limits_enabled == false); assert(!throttle_have_timer(&bs_new->throttle_state)); @@ -2038,19 +2070,14 @@ void bdrv_append(BlockDriverState *bs_new, BlockDriverState *bs_top) /* The contents of 'tmp' will become bs_top, as we are * swapping bs_new and bs_top contents. */ - bs_top->backing_hd = bs_new; - bs_top->open_flags &= ~BDRV_O_NO_BACKING; - pstrcpy(bs_top->backing_file, sizeof(bs_top->backing_file), - bs_new->filename); - pstrcpy(bs_top->backing_format, sizeof(bs_top->backing_format), - bs_new->drv ? bs_new->drv->format_name : ""); + bdrv_set_backing_hd(bs_top, bs_new); } static void bdrv_delete(BlockDriverState *bs) { assert(!bs->dev); assert(!bs->job); - assert(!bs->in_use); + assert(bdrv_op_blocker_is_empty(bs)); assert(!bs->refcnt); assert(QLIST_EMPTY(&bs->dirty_bitmaps)); @@ -2232,7 +2259,8 @@ int bdrv_commit(BlockDriverState *bs) return -ENOTSUP; } - if (bdrv_in_use(bs) || bdrv_in_use(bs->backing_hd)) { + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT, NULL) || + bdrv_op_is_blocked(bs->backing_hd, BLOCK_OP_TYPE_COMMIT, NULL)) { return -EBUSY; } @@ -2636,13 +2664,11 @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, if (ret) { goto exit; } - new_top_bs->backing_hd = base_bs; - - bdrv_refresh_limits(new_top_bs); + bdrv_set_backing_hd(new_top_bs, base_bs); QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) { /* so that bdrv_close() does not recursively close the chain */ - intermediate_state->bs->backing_hd = NULL; + bdrv_set_backing_hd(intermediate_state->bs, NULL); bdrv_unref(intermediate_state->bs); } ret = 0; @@ -3494,8 +3520,9 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset) return -ENOTSUP; if (bs->read_only) return -EACCES; - if (bdrv_in_use(bs)) + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_RESIZE, NULL)) { return -EBUSY; + } ret = drv->bdrv_truncate(bs, offset); if (ret == 0) { ret = refresh_total_sectors(bs, offset >> BDRV_SECTOR_BITS); @@ -5325,15 +5352,74 @@ void bdrv_unref(BlockDriverState *bs) } } -void bdrv_set_in_use(BlockDriverState *bs, int in_use) +struct BdrvOpBlocker { + Error *reason; + QLIST_ENTRY(BdrvOpBlocker) list; +}; + +bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp) +{ + BdrvOpBlocker *blocker; + assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); + if (!QLIST_EMPTY(&bs->op_blockers[op])) { + blocker = QLIST_FIRST(&bs->op_blockers[op]); + if (errp) { + error_setg(errp, "Device '%s' is busy: %s", + bs->device_name, error_get_pretty(blocker->reason)); + } + return true; + } + return false; +} + +void bdrv_op_block(BlockDriverState *bs, BlockOpType op, Error *reason) { - assert(bs->in_use != in_use); - bs->in_use = in_use; + BdrvOpBlocker *blocker; + assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); + + blocker = g_malloc0(sizeof(BdrvOpBlocker)); + blocker->reason = reason; + QLIST_INSERT_HEAD(&bs->op_blockers[op], blocker, list); } -int bdrv_in_use(BlockDriverState *bs) +void bdrv_op_unblock(BlockDriverState *bs, BlockOpType op, Error *reason) { - return bs->in_use; + BdrvOpBlocker *blocker, *next; + assert((int) op >= 0 && op < BLOCK_OP_TYPE_MAX); + QLIST_FOREACH_SAFE(blocker, &bs->op_blockers[op], list, next) { + if (blocker->reason == reason) { + QLIST_REMOVE(blocker, list); + g_free(blocker); + } + } +} + +void bdrv_op_block_all(BlockDriverState *bs, Error *reason) +{ + int i; + for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { + bdrv_op_block(bs, i, reason); + } +} + +void bdrv_op_unblock_all(BlockDriverState *bs, Error *reason) +{ + int i; + for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { + bdrv_op_unblock(bs, i, reason); + } +} + +bool bdrv_op_blocker_is_empty(BlockDriverState *bs) +{ + int i; + + for (i = 0; i < BLOCK_OP_TYPE_MAX; i++) { + if (!QLIST_EMPTY(&bs->op_blockers[i])) { + return false; + } + } + return true; } void bdrv_iostatus_enable(BlockDriverState *bs) |