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[Qemu-devel] [PULL 18/53] raw-posix: Fix raw_co_get_block_status() after
From: |
Stefan Hajnoczi |
Subject: |
[Qemu-devel] [PULL 18/53] raw-posix: Fix raw_co_get_block_status() after EOF |
Date: |
Mon, 3 Nov 2014 11:50:21 +0000 |
From: Max Reitz <address@hidden>
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. Regardless of that,
there should be no such assertion at all. If bdrv_getlength() returned
an outdated value and the image has been resized outside of qemu,
lseek() will return with errno == ENXIO. Just return that value as an
error then.
Setting *pnum to 0 and returning 0 should not be done here, as in that
case we should update the device length as well. So, from qemu's
perspective, the file has not been resized; it's just that there was an
error querying sectors beyond a certain point (the actual file size).
Additionally, nb_sectors should be clamped against the image end. This
was probably not an issue if FIEMAP or SEEK_HOLE/SEEK_DATA worked, but
the fallback did not take this case into account.
Reported-by: Kevin Wolf <address@hidden>
Signed-off-by: Max Reitz <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
Reviewed-by: Kevin Wolf <address@hidden>
Message-id: address@hidden
Signed-off-by: Stefan Hajnoczi <address@hidden>
---
block/raw-posix.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/block/raw-posix.c b/block/raw-posix.c
index 475cf74..a86b784 100644
--- a/block/raw-posix.c
+++ b/block/raw-posix.c
@@ -1535,10 +1535,6 @@ 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.
- * There is a virtual hole there. */
- assert(errno != -ENXIO);
-
return -errno;
}
@@ -1578,6 +1574,7 @@ static int64_t coroutine_fn
raw_co_get_block_status(BlockDriverState *bs,
int nb_sectors, int *pnum)
{
off_t start, data = 0, hole = 0;
+ int64_t total_size;
int64_t ret;
ret = fd_open(bs);
@@ -1586,6 +1583,15 @@ static int64_t coroutine_fn
raw_co_get_block_status(BlockDriverState *bs,
}
start = sector_num * BDRV_SECTOR_SIZE;
+ total_size = bdrv_getlength(bs);
+ if (total_size < 0) {
+ return total_size;
+ } else if (start >= total_size) {
+ *pnum = 0;
+ return 0;
+ } else if (start + nb_sectors * BDRV_SECTOR_SIZE > total_size) {
+ nb_sectors = DIV_ROUND_UP(total_size - start, BDRV_SECTOR_SIZE);
+ }
ret = try_seek_hole(bs, start, &data, &hole, pnum);
if (ret < 0) {
--
1.9.3
- [Qemu-devel] [PULL 08/53] ahci: Update byte count after DMA completion, (continued)
- [Qemu-devel] [PULL 08/53] ahci: Update byte count after DMA completion, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 09/53] ahci: Fix SDB FIS Construction, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 10/53] snapshot: Reset err to NULL to avoid double free, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 11/53] iotests: replace fake parallels image with authentic one, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 12/53] iotests: add v2 parallels sample image and simple test for it, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 13/53] block/parallels: fix access to not initialized memory in catalog_bitmap, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 14/53] rbd: Add support for bdrv_invalidate_cache, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 15/53] block.c: Fix type of IoOperationType variable in send_qmp_error_event(), Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 17/53] block/curl: Improve type safety of s->timeout., Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 16/53] snapshot: add bdrv_drain_all() to bdrv_snapshot_delete() to avoid concurrency problem, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 18/53] raw-posix: Fix raw_co_get_block_status() after EOF,
Stefan Hajnoczi <=
- [Qemu-devel] [PULL 19/53] raw-posix: raw_co_get_block_status() return value, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 20/53] iotests: Add test for external image truncation, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 21/53] qcow2: Allow "full" discard, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 22/53] qcow2: Implement bdrv_make_empty(), Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 23/53] qcow2: Optimize bdrv_make_empty(), Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 24/53] blockjob: Introduce block_job_complete_sync(), Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 26/53] iotests: Omit length/offset test in 040 and 041, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 25/53] blockjob: Add "ready" field, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 27/53] block/mirror: Improve progress report, Stefan Hajnoczi, 2014/11/03
- [Qemu-devel] [PULL 28/53] qemu-img: Implement commit like QMP, Stefan Hajnoczi, 2014/11/03