[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Qemu-devel] [PATCH v2 1/2] raw-posix: Fix raw_co_get_block_status() aft
From: |
Max Reitz |
Subject: |
[Qemu-devel] [PATCH v2 1/2] raw-posix: Fix raw_co_get_block_status() after EOF |
Date: |
Mon, 22 Sep 2014 17:36:18 +0200 |
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.
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>
---
block/raw-posix.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/block/raw-posix.c b/block/raw-posix.c
index a253697..dd57992 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;
}
@@ -1552,6 +1552,7 @@ 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);
@@ -1560,6 +1561,13 @@ static int64_t coroutine_fn
raw_co_get_block_status(BlockDriverState *bs,
}
start = sector_num * BDRV_SECTOR_SIZE;
+ total_size = bdrv_getlength(bs);
+ if (start >= total_size) {
+ *pnum = 0;
+ return 0;
+ } else if (start + nb_sectors * BDRV_SECTOR_SIZE > total_size) {
+ nb_sectors = (total_size - start) / BDRV_SECTOR_SIZE;
+ }
ret = try_fiemap(bs, start, &data, &hole, nb_sectors, pnum);
if (ret < 0) {
--
2.1.0