[Qemu-devel] [PATCH v3 03/29] block: Update BlockLimits when they might have changed

[Kevin Wolf <kwolf@redhat.com>]

When reopening with different flags, or when backing files disappear
from the chain, the limits may change. Make sure they get updated in
these cases.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Wenchao Xia <xiawenc@linux.vnet.ibm.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
---
 block.c               | 5 ++++-
 block/stream.c        | 2 ++
 include/block/block.h | 1 +
 3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/block.c b/block.c
index 20f85cb..9a8562d 100644
--- a/block.c
+++ b/block.c
@@ -479,7 +479,7 @@ int bdrv_create_file(const char* filename, QEMUOptionParameter *options,
     return ret;
 }
 
-static int bdrv_refresh_limits(BlockDriverState *bs)
+int bdrv_refresh_limits(BlockDriverState *bs)
 {
     BlockDriver *drv = bs->drv;
 
@@ -1464,6 +1464,8 @@ void bdrv_reopen_commit(BDRVReopenState *reopen_state)
     reopen_state->bs->enable_write_cache = !!(reopen_state->flags &
                                               BDRV_O_CACHE_WB);
     reopen_state->bs->read_only = !(reopen_state->flags & BDRV_O_RDWR);
+
+    bdrv_refresh_limits(reopen_state->bs);
 }
 
 /*
@@ -2261,6 +2263,7 @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
     }
     new_top_bs->backing_hd = base_bs;
 
+    bdrv_refresh_limits(new_top_bs);
 
     QSIMPLEQ_FOREACH_SAFE(intermediate_state, &states_to_delete, entry, next) {
         /* so that bdrv_close() does not recursively close the chain */
diff --git a/block/stream.c b/block/stream.c
index 46bec7d..dd0b4ac 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -75,6 +75,8 @@ static void close_unused_images(BlockDriverState *top, BlockDriverState *base,
         unused->backing_hd = NULL;
         bdrv_unref(unused);
     }
+
+    bdrv_refresh_limits(top);
 }
 
 static void coroutine_fn stream_run(void *opaque)
diff --git a/include/block/block.h b/include/block/block.h
index 36efaea..64fb319 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -249,6 +249,7 @@ int bdrv_truncate(BlockDriverState *bs, int64_t offset);
 int64_t bdrv_getlength(BlockDriverState *bs);
 int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
+int bdrv_refresh_limits(BlockDriverState *bs);
 int bdrv_commit(BlockDriverState *bs);
 int bdrv_commit_all(void);
 int bdrv_change_backing_file(BlockDriverState *bs,
-- 
1.8.1.4