[Qemu-devel] [PATCHv2 2/4] block: immediately cancel oversized read/write requests

[Peter Lieven <pl@kamp.de>]

Signed-off-by: Peter Lieven <pl@kamp.de>
---
 block.c      |   14 ++++++++++++++
 trace-events |    2 ++
 2 files changed, 16 insertions(+)

diff --git a/block.c b/block.c
index c87e9fd..965e9bc 100644
--- a/block.c
+++ b/block.c
@@ -3215,6 +3215,13 @@ static int coroutine_fn bdrv_co_do_readv(BlockDriverState *bs,
         return -EINVAL;
     }
 
+    if (bs->bl.max_transfer_length &&
+        nb_sectors > bs->bl.max_transfer_length) {
+        trace_bdrv_co_do_readv_toobig(bs, sector_num, nb_sectors,
+                                      bs->bl.max_transfer_length);
+        return -EINVAL;
+    }
+
     return bdrv_co_do_preadv(bs, sector_num << BDRV_SECTOR_BITS,
                              nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
 }
@@ -3507,6 +3514,13 @@ static int coroutine_fn bdrv_co_do_writev(BlockDriverState *bs,
         return -EINVAL;
     }
 
+    if (bs->bl.max_transfer_length &&
+        nb_sectors > bs->bl.max_transfer_length) {
+        trace_bdrv_co_do_writev_toobig(bs, sector_num, nb_sectors,
+                                       bs->bl.max_transfer_length);
+        return -EINVAL;
+    }
+
     return bdrv_co_do_pwritev(bs, sector_num << BDRV_SECTOR_BITS,
                               nb_sectors << BDRV_SECTOR_BITS, qiov, flags);
 }
diff --git a/trace-events b/trace-events
index fb58963..fe2c5d8 100644
--- a/trace-events
+++ b/trace-events
@@ -68,8 +68,10 @@ bdrv_aio_writev(void *bs, int64_t sector_num, int nb_sectors, void *opaque) "bs
 bdrv_aio_write_zeroes(void *bs, int64_t sector_num, int nb_sectors, int flags, void *opaque) "bs %p sector_num %"PRId64" nb_sectors %d flags %#x opaque %p"
 bdrv_lock_medium(void *bs, bool locked) "bs %p locked %d"
 bdrv_co_readv(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
+bdrv_co_do_readv_toobig(void *bs, int64_t sector_num, int nb_sector, int max_transfer_length) "bs %p sector_num %"PRId64" nb_sectors %d bs->bl.max_transfer_length %d"
 bdrv_co_copy_on_readv(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
 bdrv_co_writev(void *bs, int64_t sector_num, int nb_sector) "bs %p sector_num %"PRId64" nb_sectors %d"
+bdrv_co_do_writev_toobig(void *bs, int64_t sector_num, int nb_sector, int max_transfer_length) "bs %p sector_num %"PRId64" nb_sectors %d bs->bl.max_transfer_length %d"
 bdrv_co_write_zeroes(void *bs, int64_t sector_num, int nb_sector, int flags) "bs %p sector_num %"PRId64" nb_sectors %d flags %#x"
 bdrv_co_io_em(void *bs, int64_t sector_num, int nb_sectors, int is_write, void *acb) "bs %p sector_num %"PRId64" nb_sectors %d is_write %d acb %p"
 bdrv_co_do_copy_on_readv(void *bs, int64_t sector_num, int nb_sectors, int64_t cluster_sector_num, int cluster_nb_sectors) "bs %p sector_num %"PRId64" nb_sectors %d cluster_sector_num %"PRId64" cluster_nb_sectors %d"
-- 
1.7.9.5