commit 355ef4ac95a7a47d5c7201ccd910056a100d2fdf
author Kevin Wolf <kwolf@redhat.com> Wed Dec 11 20:14:09 2013 +0100
committer Kevin Wolf <kwolf@redhat.com> Fri Jan 24 17:40:01 2014 +0100
tree 45ebc3bfbffb57d48c82c3e3b6aa730552c338fe
parent 466ad822deef3a03757d505218a52993c5d56b5d

block: Update BlockLimits when they might have changed

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>
Reviewed-by: Benoît Canet <benoit@irqsave.net>

block.c

diff --git a/block.c b/block.c
index 8a66927..9d0cfc4 100644
--- a/block.c
+++ b/block.c
@@ -483,7 +483,7 @@
     return ret;
 }
 
-static int bdrv_refresh_limits(BlockDriverState *bs)
+int bdrv_refresh_limits(BlockDriverState *bs)
 {
     BlockDriver *drv = bs->drv;
 
@@ -1607,6 +1607,8 @@
     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);
 }
 
 /*
@@ -2441,6 +2443,7 @@
     }
     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 */

block/stream.c

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 @@
         unused->backing_hd = NULL;
         bdrv_unref(unused);
     }
+
+    bdrv_refresh_limits(top);
 }
 
 static void coroutine_fn stream_run(void *opaque)

include/block/block.h

diff --git a/include/block/block.h b/include/block/block.h
index 59d9f12..00a8790 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -253,6 +253,7 @@
 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,