From bfb197e0d998bea8741c65492b2b42f443729249 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Tue, 7 Oct 2014 13:59:11 +0200 Subject: block: Eliminate BlockDriverState member device_name[] device_name[] can become non-empty only in bdrv_new_root() and bdrv_move_feature_fields(). The latter is used only to undo damage done by bdrv_swap(). The former is called only by blk_new_with_bs(). Therefore, when a BlockDriverState's device_name[] is non-empty, then it's been created with a BlockBackend, and vice versa. Furthermore, blk_new_with_bs() keeps the two names equal. Therefore, device_name[] is redundant. Eliminate it. Signed-off-by: Markus Armbruster Reviewed-by: Max Reitz Signed-off-by: Kevin Wolf --- block.c | 49 +++++++++++++++++++++++++++---------------------- 1 file changed, 27 insertions(+), 22 deletions(-) (limited to 'block.c') diff --git a/block.c b/block.c index d13d29b7b8..5c37970a4a 100644 --- a/block.c +++ b/block.c @@ -28,6 +28,7 @@ #include "block/blockjob.h" #include "qemu/module.h" #include "qapi/qmp/qjson.h" +#include "sysemu/block-backend.h" #include "sysemu/sysemu.h" #include "qemu/notify.h" #include "block/coroutine.h" @@ -360,9 +361,7 @@ BlockDriverState *bdrv_new_root(const char *device_name, Error **errp) bs = bdrv_new(); - pstrcpy(bs->device_name, sizeof(bs->device_name), device_name); QTAILQ_INSERT_TAIL(&bdrv_states, bs, device_list); - return bs; } @@ -1168,7 +1167,7 @@ void bdrv_set_backing_hd(BlockDriverState *bs, BlockDriverState *backing_hd) } else if (backing_hd) { error_setg(&bs->backing_blocker, "device is used as backing hd of '%s'", - bs->device_name); + bdrv_get_device_name(bs)); } bs->backing_hd = backing_hd; @@ -1542,7 +1541,7 @@ int bdrv_open(BlockDriverState **pbs, const char *filename, } else { error_setg(errp, "Block format '%s' used by device '%s' doesn't " "support the option '%s'", drv->format_name, - bs->device_name, entry->key); + bdrv_get_device_name(bs), entry->key); } ret = -EINVAL; @@ -1749,7 +1748,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, if (!(reopen_state->bs->open_flags & BDRV_O_ALLOW_RDWR) && reopen_state->flags & BDRV_O_RDWR) { error_set(errp, QERR_DEVICE_IS_READ_ONLY, - reopen_state->bs->device_name); + bdrv_get_device_name(reopen_state->bs)); goto error; } @@ -1776,7 +1775,7 @@ int bdrv_reopen_prepare(BDRVReopenState *reopen_state, BlockReopenQueue *queue, /* It is currently mandatory to have a bdrv_reopen_prepare() * handler for each supported drv. */ error_set(errp, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, - drv->format_name, reopen_state->bs->device_name, + drv->format_name, bdrv_get_device_name(reopen_state->bs), "reopening of file"); ret = -1; goto error; @@ -1964,10 +1963,17 @@ void bdrv_drain_all(void) Also, NULL terminate the device_name to prevent double remove */ void bdrv_make_anon(BlockDriverState *bs) { - if (bs->device_name[0] != '\0') { + /* + * Take care to remove bs from bdrv_states only when it's actually + * in it. Note that bs->device_list.tqe_prev is initially null, + * and gets set to non-null by QTAILQ_INSERT_TAIL(). Establish + * the useful invariant "bs in bdrv_states iff bs->tqe_prev" by + * resetting it to null on remove. + */ + if (bs->device_list.tqe_prev) { QTAILQ_REMOVE(&bdrv_states, bs, device_list); + bs->device_list.tqe_prev = NULL; } - bs->device_name[0] = '\0'; if (bs->node_name[0] != '\0') { QTAILQ_REMOVE(&graph_bdrv_states, bs, node_list); } @@ -2021,8 +2027,6 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest, 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; bs_dest->blk = bs_src->blk; @@ -2038,7 +2042,7 @@ static void bdrv_move_feature_fields(BlockDriverState *bs_dest, * This will modify the BlockDriverState fields, and swap contents * between bs_new and bs_old. Both bs_new and bs_old are modified. * - * bs_new must be nameless and not attached to a BlockBackend. + * bs_new must not be attached to a BlockBackend. * * This function does not create any image files. */ @@ -2057,8 +2061,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) QTAILQ_REMOVE(&graph_bdrv_states, bs_old, node_list); } - /* bs_new must be nameless and shouldn't have anything fancy enabled */ - assert(bs_new->device_name[0] == '\0'); + /* bs_new must be unattached and shouldn't have anything fancy enabled */ assert(!bs_new->blk); assert(QLIST_EMPTY(&bs_new->dirty_bitmaps)); assert(bs_new->job == NULL); @@ -2075,8 +2078,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) bdrv_move_feature_fields(bs_old, bs_new); bdrv_move_feature_fields(bs_new, &tmp); - /* bs_new must remain nameless and unattached */ - assert(bs_new->device_name[0] == '\0'); + /* bs_new must remain unattached */ assert(!bs_new->blk); /* Check a few fields that should remain attached to the device */ @@ -2104,7 +2106,7 @@ void bdrv_swap(BlockDriverState *bs_new, BlockDriverState *bs_old) * This will modify the BlockDriverState fields, and swap contents * between bs_new and bs_top. Both bs_new and bs_top are modified. * - * bs_new must be nameless and not attached to a BlockBackend. + * bs_new must not be attached to a BlockBackend. * * This function does not create any image files. */ @@ -3820,7 +3822,7 @@ BlockDriverState *bdrv_find(const char *name) BlockDriverState *bs; QTAILQ_FOREACH(bs, &bdrv_states, device_list) { - if (!strcmp(name, bs->device_name)) { + if (!strcmp(name, bdrv_get_device_name(bs))) { return bs; } } @@ -3906,9 +3908,9 @@ BlockDriverState *bdrv_next(BlockDriverState *bs) return QTAILQ_NEXT(bs, device_list); } -const char *bdrv_get_device_name(BlockDriverState *bs) +const char *bdrv_get_device_name(const BlockDriverState *bs) { - return bs->device_name; + return bs->blk ? blk_name(bs->blk) : ""; } int bdrv_get_flags(BlockDriverState *bs) @@ -5262,13 +5264,15 @@ int bdrv_media_changed(BlockDriverState *bs) void bdrv_eject(BlockDriverState *bs, bool eject_flag) { BlockDriver *drv = bs->drv; + const char *device_name; if (drv && drv->bdrv_eject) { drv->bdrv_eject(bs, eject_flag); } - if (bs->device_name[0] != '\0') { - qapi_event_send_device_tray_moved(bdrv_get_device_name(bs), + device_name = bdrv_get_device_name(bs); + if (device_name[0] != '\0') { + qapi_event_send_device_tray_moved(device_name, eject_flag, &error_abort); } } @@ -5478,7 +5482,8 @@ bool bdrv_op_is_blocked(BlockDriverState *bs, BlockOpType op, Error **errp) 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)); + bdrv_get_device_name(bs), + error_get_pretty(blocker->reason)); } return true; } -- cgit v1.2.1