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authorStefan Hajnoczi <stefanha@redhat.com>2014-03-26 13:05:56 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2014-04-01 15:22:35 +0200
commitb404bf854217dbe8a5649449eb3ad33777f7d900 (patch)
tree3fc3cd3965a783341aa1653d147ad5e9aee8ef7e /block
parent73ed27ec28a1dbebdd2ae792284151f029950fbe (diff)
dmg: drop broken bdrv_pread() loop
It is not necessary to check errno for EINTR and the block layer does not produce short reads. Therefore we can drop the loop that attempts to read a compressed chunk. The loop is buggy because it incorrectly adds the transferred bytes twice: do { ret = bdrv_pread(...); i += ret; } while (ret >= 0 && ret + i < s->lengths[chunk]); Luckily we can drop the loop completely and perform a single bdrv_pread(). Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'block')
-rw-r--r--block/dmg.c15
1 files changed, 2 insertions, 13 deletions
diff --git a/block/dmg.c b/block/dmg.c
index f4f3e8e9f2..1cc5426d8c 100644
--- a/block/dmg.c
+++ b/block/dmg.c
@@ -298,21 +298,10 @@ static inline int dmg_read_chunk(BlockDriverState *bs, int sector_num)
s->current_chunk = s->n_chunks;
switch (s->types[chunk]) {
case 0x80000005: { /* zlib compressed */
- int i;
-
/* we need to buffer, because only the chunk as whole can be
* inflated. */
- i = 0;
- do {
- ret = bdrv_pread(bs->file, s->offsets[chunk] + i,
- s->compressed_chunk + i,
- s->lengths[chunk] - i);
- if (ret < 0 && errno == EINTR) {
- ret = 0;
- }
- i += ret;
- } while (ret >= 0 && ret + i < s->lengths[chunk]);
-
+ ret = bdrv_pread(bs->file, s->offsets[chunk],
+ s->compressed_chunk, s->lengths[chunk]);
if (ret != s->lengths[chunk]) {
return -1;
}