9pfs: deduplicate iounit code

Remove redundant code that translates host fileystem's block
size into 9p client (guest side) block size.

Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <129bb71d5119e61d335f1e3107e472e4beea223a.1632758315.git.qemu_oss@crudebyte.com>
This commit is contained in:
Christian Schoenebeck 2021-09-27 17:45:00 +02:00
parent 669ced09b3
commit b565bccb00

View File

@ -1262,18 +1262,26 @@ static int coroutine_fn stat_to_v9stat(V9fsPDU *pdu, V9fsPath *path,
#define P9_STATS_ALL 0x00003fffULL /* Mask for All fields above */
static int32_t stat_to_iounit(const V9fsPDU *pdu, const struct stat *stbuf)
/**
* Convert host filesystem's block size into an appropriate block size for
* 9p client (guest OS side). The value returned suggests an "optimum" block
* size for 9p I/O, i.e. to maximize performance.
*
* @pdu: 9p client request
* @blksize: host filesystem's block size
*/
static int32_t blksize_to_iounit(const V9fsPDU *pdu, int32_t blksize)
{
int32_t iounit = 0;
V9fsState *s = pdu->s;
/*
* iounit should be multiples of st_blksize (host filesystem block size)
* iounit should be multiples of blksize (host filesystem block size)
* as well as less than (client msize - P9_IOHDRSZ)
*/
if (stbuf->st_blksize) {
iounit = stbuf->st_blksize;
iounit *= (s->msize - P9_IOHDRSZ) / stbuf->st_blksize;
if (blksize) {
iounit = blksize;
iounit *= (s->msize - P9_IOHDRSZ) / blksize;
}
if (!iounit) {
iounit = s->msize - P9_IOHDRSZ;
@ -1281,6 +1289,11 @@ static int32_t stat_to_iounit(const V9fsPDU *pdu, const struct stat *stbuf)
return iounit;
}
static int32_t stat_to_iounit(const V9fsPDU *pdu, const struct stat *stbuf)
{
return blksize_to_iounit(pdu, stbuf->st_blksize);
}
static int stat_to_v9stat_dotl(V9fsPDU *pdu, const struct stat *stbuf,
V9fsStatDotl *v9lstat)
{
@ -1899,23 +1912,9 @@ out_nofid:
static int32_t coroutine_fn get_iounit(V9fsPDU *pdu, V9fsPath *path)
{
struct statfs stbuf;
int32_t iounit = 0;
V9fsState *s = pdu->s;
int err = v9fs_co_statfs(pdu, path, &stbuf);
/*
* iounit should be multiples of f_bsize (host filesystem block size
* and as well as less than (client msize - P9_IOHDRSZ))
*/
if (!v9fs_co_statfs(pdu, path, &stbuf)) {
if (stbuf.f_bsize) {
iounit = stbuf.f_bsize;
iounit *= (s->msize - P9_IOHDRSZ) / stbuf.f_bsize;
}
}
if (!iounit) {
iounit = s->msize - P9_IOHDRSZ;
}
return iounit;
return blksize_to_iounit(pdu, (err >= 0) ? stbuf.f_bsize : 0);
}
static void coroutine_fn v9fs_open(void *opaque)