Block drivers can implement this new operation .bdrv_lockf to actually lock the image in the protocol specific way.
Signed-off-by: Fam Zheng <[email protected]> --- block.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++ include/block/block.h | 4 +++- include/block/block_int.h | 5 +++++ include/hw/block/block.h | 2 ++ 4 files changed, 62 insertions(+), 1 deletion(-) diff --git a/block.c b/block.c index 493ecf3..9d600df 100644 --- a/block.c +++ b/block.c @@ -235,6 +235,7 @@ BlockDriverState *bdrv_new(void) notifier_with_return_list_init(&bs->before_write_notifiers); bs->refcnt = 1; bs->aio_context = qemu_get_aio_context(); + bs->cur_lock = IMAGE_LOCK_MODE__MAX; qemu_co_queue_init(&bs->flush_queue); @@ -925,6 +926,48 @@ out: g_free(gen_node_name); } +ImageLockMode bdrv_lock_mode_from_flags(int flags) +{ + if (flags & BDRV_O_NO_LOCK) { + return IMAGE_LOCK_MODE_NOLOCK; + } else if (flags & BDRV_O_SHARED_LOCK) { + return IMAGE_LOCK_MODE_SHARED; + } else if (flags & BDRV_O_EXCLUSIVE_LOCK) { + return IMAGE_LOCK_MODE_EXCLUSIVE; + } else { + return IMAGE_LOCK_MODE_AUTO; + } +} + +ImageLockMode bdrv_get_lock_mode(BlockDriverState *bs) +{ + return bs->cur_lock; +} + +int bdrv_set_lock_mode(BlockDriverState *bs, ImageLockMode mode) +{ + int ret; + + if (bs->cur_lock == mode) { + return 0; + } else if (!bs->drv) { + return -ENOMEDIUM; + } else if (!bs->drv->bdrv_lockf) { + if (bs->file) { + return bdrv_set_lock_mode(bs->file->bs, mode); + } + return 0; + } + ret = bs->drv->bdrv_lockf(bs, mode); + if (ret == -ENOTSUP) { + /* Handle it the same way as !bs->drv->bdrv_lockf */ + ret = 0; + } else if (ret == 0) { + bs->cur_lock = mode; + } + return ret; +} + static QemuOptsList bdrv_runtime_opts = { .name = "bdrv_common", .head = QTAILQ_HEAD_INITIALIZER(bdrv_runtime_opts.head), @@ -1076,6 +1119,10 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file, goto free_and_fail; } + if (open_flags & BDRV_O_INACTIVE) { + open_flags = (open_flags & ~BDRV_O_LOCK_MASK) & BDRV_O_NO_LOCK; + } + ret = refresh_total_sectors(bs, bs->total_sectors); if (ret < 0) { error_setg_errno(errp, -ret, "Could not refresh total sector count"); @@ -2273,6 +2320,7 @@ static void bdrv_close(BlockDriverState *bs) if (bs->drv) { BdrvChild *child, *next; + bdrv_set_lock_mode(bs, IMAGE_LOCK_MODE_NOLOCK); bs->drv->bdrv_close(bs); bs->drv = NULL; @@ -3188,6 +3236,9 @@ void bdrv_invalidate_cache(BlockDriverState *bs, Error **errp) error_setg_errno(errp, -ret, "Could not refresh total sector count"); return; } + if (bs->cur_lock != IMAGE_LOCK_MODE__MAX) { + bdrv_set_lock_mode(bs, bs->cur_lock); + } } void bdrv_invalidate_cache_all(Error **errp) @@ -3230,6 +3281,7 @@ static int bdrv_inactivate_recurse(BlockDriverState *bs, } if (setting_flag) { + ret = bdrv_set_lock_mode(bs, IMAGE_LOCK_MODE_NOLOCK); bs->open_flags |= BDRV_O_INACTIVE; } return 0; diff --git a/include/block/block.h b/include/block/block.h index cecab7a..828ab14 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -272,7 +272,8 @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top, BlockDriverState *bdrv_find_overlay(BlockDriverState *active, BlockDriverState *bs); BlockDriverState *bdrv_find_base(BlockDriverState *bs); - +ImageLockMode bdrv_lock_mode_from_flags(int flags); +ImageLockMode bdrv_get_lock_mode(BlockDriverState *bs); typedef struct BdrvCheckResult { int corruptions; @@ -529,5 +530,6 @@ void bdrv_drained_end(BlockDriverState *bs); void bdrv_add_child(BlockDriverState *parent, BlockDriverState *child, Error **errp); void bdrv_del_child(BlockDriverState *parent, BdrvChild *child, Error **errp); +int bdrv_set_lock_mode(BlockDriverState *bs, ImageLockMode mode); #endif diff --git a/include/block/block_int.h b/include/block/block_int.h index 3e79228..486e1ea 100644 --- a/include/block/block_int.h +++ b/include/block/block_int.h @@ -319,6 +319,10 @@ struct BlockDriver { Error **errp); void (*bdrv_del_child)(BlockDriverState *parent, BdrvChild *child, Error **errp); + /** + * Lock/unlock the image. + */ + int (*bdrv_lockf)(BlockDriverState *bs, ImageLockMode mode); QLIST_ENTRY(BlockDriver) list; }; @@ -528,6 +532,7 @@ struct BlockDriverState { unsigned io_plug_disabled; int quiesce_counter; + ImageLockMode cur_lock; }; struct BlockBackendRootState { diff --git a/include/hw/block/block.h b/include/hw/block/block.h index df9d207..8c04469 100644 --- a/include/hw/block/block.h +++ b/include/hw/block/block.h @@ -12,11 +12,13 @@ #define HW_BLOCK_H #include "qemu-common.h" +#include "block/block.h" /* Configuration */ typedef struct BlockConf { BlockBackend *blk; + ImageLockMode lock_mode; uint16_t physical_block_size; uint16_t logical_block_size; uint16_t min_io_size; -- 2.7.4
