block-raw.c currently doesn't cope with partial reads and writes, here
is a patch.
Signed-off-by: Samuel Thibault <[EMAIL PROTECTED]>
Index: block-raw.c
===================================================================
RCS file: /sources/qemu/qemu/block-raw.c,v
retrieving revision 1.25
diff -u -p -r1.25 block-raw.c
--- block-raw.c 20 Oct 2007 20:40:05 -0000 1.25
+++ block-raw.c 9 Nov 2007 17:16:35 -0000
@@ -142,7 +142,8 @@ static int raw_pread(BlockDriverState *b
uint8_t *buf, int count)
{
BDRVRawState *s = bs->opaque;
- int ret;
+ int ret, tries;
+ uint64_t done;
ret = fd_open(bs);
if (ret < 0)
@@ -160,35 +161,32 @@ static int raw_pread(BlockDriverState *b
}
s->lseek_err_cnt=0;
- ret = read(s->fd, buf, count);
- if (ret == count)
- goto label__raw_read__success;
-
- DEBUG_BLOCK_PRINT("raw_pread(%d:%s, %" PRId64 ", %p, %d) [%" PRId64
- "] read failed %d : %d = %s\n",
- s->fd, bs->filename, offset, buf, count,
- bs->total_sectors, ret, errno, strerror(errno));
-
- /* Try harder for CDrom. */
- if (bs->type == BDRV_TYPE_CDROM) {
- lseek(s->fd, offset, SEEK_SET);
- ret = read(s->fd, buf, count);
- if (ret == count)
- goto label__raw_read__success;
- lseek(s->fd, offset, SEEK_SET);
- ret = read(s->fd, buf, count);
- if (ret == count)
- goto label__raw_read__success;
-
- DEBUG_BLOCK_PRINT("raw_pread(%d:%s, %" PRId64 ", %p, %d) [%" PRId64
- "] retry read failed %d : %d = %s\n",
- s->fd, bs->filename, offset, buf, count,
- bs->total_sectors, ret, errno, strerror(errno));
+ tries = 0;
+ for (done = 0; done < count; done += ret) {
+ ret = read(s->fd, buf + done, count - done);
+ if (ret > 0) {
+ tries = 0;
+ } else if (ret == 0) {
+ DEBUG_BLOCK_PRINT("raw_pread(%d:%s, %" PRId64 ", %p, %d) [%" PRId64
+ "] read met end of file\n",
+ s->fd, bs->filename, offset, buf, count,
+ bs->total_sectors);
+ return -1;
+ } else {
+ /* Try harder for CDrom. */
+ if (errno == EINTR ||
+ (bs->type == BDRV_TYPE_CDROM && ++tries < 3)) {
+ ret = 0;
+ continue;
+ }
+ DEBUG_BLOCK_PRINT("raw_pread(%d:%s, %" PRId64 ", %p, %d) [%" PRId64
+ "] read failed %d : %d = %s\n",
+ s->fd, bs->filename, offset, buf, count,
+ bs->total_sectors, ret, errno, strerror(errno));
+ return -1;
+ }
}
-
-label__raw_read__success:
-
- return ret;
+ return count;
}
static int raw_pwrite(BlockDriverState *bs, int64_t offset,
@@ -196,6 +194,7 @@ static int raw_pwrite(BlockDriverState *
{
BDRVRawState *s = bs->opaque;
int ret;
+ uint64_t done;
ret = fd_open(bs);
if (ret < 0)
@@ -213,18 +212,21 @@ static int raw_pwrite(BlockDriverState *
}
s->lseek_err_cnt = 0;
- ret = write(s->fd, buf, count);
- if (ret == count)
- goto label__raw_write__success;
-
- DEBUG_BLOCK_PRINT("raw_pwrite(%d:%s, %" PRId64 ", %p, %d) [%" PRId64
- "] write failed %d : %d = %s\n",
- s->fd, bs->filename, offset, buf, count,
- bs->total_sectors, ret, errno, strerror(errno));
-
-label__raw_write__success:
-
- return ret;
+ for (done = 0; done < count; done += ret) {
+ ret = write(s->fd, buf + done, count - done);
+ if (ret == -1) {
+ if (errno == EINTR) {
+ ret = 0;
+ continue;
+ }
+ DEBUG_BLOCK_PRINT("raw_pwrite(%d:%s, %" PRId64 ", %p, %d) [%"
PRId64
+ "] write failed %d : %d = %s\n",
+ s->fd, bs->filename, offset, buf, count,
+ bs->total_sectors, ret, errno, strerror(errno));
+ return -1;
+ }
+ }
+ return count;
}
/***********************************************************/
