| From 69fe324e32aad7e1afc6ad14021a6a08ad52646c Mon Sep 17 00:00:00 2001 |
| From: Max Reitz <mreitz@redhat.com> |
| Date: Sat, 13 Jun 2015 16:22:27 +0200 |
| Subject: [PATCH 33/42] block: Respect underlying file's EOF |
| |
| Message-id: <1434212556-3927-34-git-send-email-mreitz@redhat.com> |
| Patchwork-id: 66052 |
| O-Subject: [RHEL-7.2 qemu-kvm PATCH 33/42] block: Respect underlying file's EOF |
| Bugzilla: 1129893 |
| RH-Acked-by: Jeffrey Cody <jcody@redhat.com> |
| RH-Acked-by: Fam Zheng <famz@redhat.com> |
| RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com> |
| |
| BZ: 1129893 |
| |
| When falling through to the underlying file in |
| bdrv_co_get_block_status(), if it returns that the query offset is |
| beyond the file end (by setting *pnum to 0), return the range to be |
| zero and do not let the number of sectors for which information could be |
| obtained be overwritten. |
| |
| Signed-off-by: Max Reitz <mreitz@redhat.com> |
| Signed-off-by: Kevin Wolf <kwolf@redhat.com> |
| (cherry picked from commit 59c9a95fd29cfb3296ee58e8a446df251d14a459) |
| |
| Signed-off-by: Max Reitz <mreitz@redhat.com> |
| Signed-off-by: Miroslav Rezanina <mrezanin@redhat.com> |
| |
| block.c | 15 +++++++++++++-- |
| 1 file changed, 13 insertions(+), 2 deletions(-) |
| |
| diff --git a/block.c b/block.c |
| index 22ab762..fa6e192 100644 |
| |
| |
| @@ -3797,13 +3797,24 @@ static int64_t coroutine_fn bdrv_co_get_block_status(BlockDriverState *bs, |
| if (bs->file && |
| (ret & BDRV_BLOCK_DATA) && !(ret & BDRV_BLOCK_ZERO) && |
| (ret & BDRV_BLOCK_OFFSET_VALID)) { |
| + int file_pnum; |
| + |
| ret2 = bdrv_co_get_block_status(bs->file, ret >> BDRV_SECTOR_BITS, |
| - *pnum, pnum); |
| + *pnum, &file_pnum); |
| if (ret2 >= 0) { |
| /* Ignore errors. This is just providing extra information, it |
| * is useful but not necessary. |
| */ |
| - ret |= (ret2 & BDRV_BLOCK_ZERO); |
| + if (!file_pnum) { |
| + /* !file_pnum indicates an offset at or beyond the EOF; it is |
| + * perfectly valid for the format block driver to point to such |
| + * offsets, so catch it and mark everything as zero */ |
| + ret |= BDRV_BLOCK_ZERO; |
| + } else { |
| + /* Limit request to the range reported by the protocol driver */ |
| + *pnum = file_pnum; |
| + ret |= (ret2 & BDRV_BLOCK_ZERO); |
| + } |
| } |
| } |
| |
| -- |
| 1.8.3.1 |
| |