diff options
Diffstat (limited to 'hw/9pfs')
-rw-r--r-- | hw/9pfs/9p.c | 41 |
1 files changed, 20 insertions, 21 deletions
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 708b030..5c57344 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -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) |