block: Add BDRV_BLOCK_EOF to bdrv_get_block_status()

Just as the block layer already sets BDRV_BLOCK_ALLOCATED as a
shortcut for subsequent operations, there are also some optimizations
that are made easier if we can quickly tell that *pnum will advance
us to the end of a file, via a new BDRV_BLOCK_EOF which gets set
by the block layer.

This just plumbs up the new bit; subsequent patches will make use
of it.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20170505021500.19315-2-eblake@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Fam Zheng <famz@redhat.com>
This commit is contained in:
Eric Blake 2017-05-04 21:14:59 -05:00 committed by Fam Zheng
parent 36f87b4513
commit fb0d8654ff
2 changed files with 13 additions and 4 deletions

View file

@ -129,6 +129,7 @@ typedef struct HDGeometry {
* BDRV_BLOCK_OFFSET_VALID: an associated offset exists for accessing raw data
* BDRV_BLOCK_ALLOCATED: the content of the block is determined by this
* layer (short for DATA || ZERO), set by block layer
* BDRV_BLOCK_EOF: the returned pnum covers through end of file for this layer
*
* Internal flag:
* BDRV_BLOCK_RAW: used internally to indicate that the request was
@ -157,6 +158,7 @@ typedef struct HDGeometry {
#define BDRV_BLOCK_OFFSET_VALID 0x04
#define BDRV_BLOCK_RAW 0x08
#define BDRV_BLOCK_ALLOCATED 0x10
#define BDRV_BLOCK_EOF 0x20
#define BDRV_BLOCK_OFFSET_MASK BDRV_SECTOR_MASK
typedef QSIMPLEQ_HEAD(BlockReopenQueue, BlockReopenQueueEntry) BlockReopenQueue;