[Qemu-devel] [PATCH 1/2] raw-posix: Fix raw_co_get_block_status() after EOF

[Max Reitz <mreitz@redhat.com>]

As its comment states, raw_co_get_block_status() should unconditionally
return 0 and set *pnum to 0 for after EOF.

An assertion after lseek(..., SEEK_HOLE) tried to catch this case by
asserting that errno != -ENXIO (which would indicate a position after
the EOF); but it should be errno != ENXIO instead. Fix this, too.

Reported-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
---
 block/raw-posix.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/block/raw-posix.c b/block/raw-posix.c
index a253697..de4e3f3 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -1509,9 +1509,9 @@ static int64_t try_seek_hole(BlockDriverState *bs, off_t start, off_t *data,
 
     *hole = lseek(s->fd, start, SEEK_HOLE);
     if (*hole == -1) {
-        /* -ENXIO indicates that sector_num was past the end of the file.
+        /* ENXIO indicates that sector_num was past the end of the file.
          * There is a virtual hole there.  */
-        assert(errno != -ENXIO);
+        assert(errno != ENXIO);
 
         return -errno;
     }
@@ -1560,6 +1560,10 @@ static int64_t coroutine_fn raw_co_get_block_status(BlockDriverState *bs,
     }
 
     start = sector_num * BDRV_SECTOR_SIZE;
+    if (start >= bdrv_getlength(bs)) {
+        *pnum = 0;
+        return 0;
+    }
 
     ret = try_fiemap(bs, start, &data, &hole, nb_sectors, pnum);
     if (ret < 0) {
-- 
2.1.0