Sripathi Kodi wrote: > On Tue, 1 Jun 2010 19:47:14 +0530 > "M. Mohan Kumar" <mo...@in.ibm.com> wrote: > >> Compute iounit based on the host filesystem block size and pass it to >> client with open/create response. Also return iounit as statfs's f_bsize >> for optimal block size transfers. >> >> Signed-off-by: M. Mohan Kumar <mo...@in.ibm.com> >> --- >> hw/virtio-9p.c | 56 >> ++++++++++++++++++++++++++++++++++++++++++-------------- >> hw/virtio-9p.h | 3 +++ >> 2 files changed, 45 insertions(+), 14 deletions(-) >> >> diff --git a/hw/virtio-9p.c b/hw/virtio-9p.c >> index f087122..4357f1f 100644 >> --- a/hw/virtio-9p.c >> +++ b/hw/virtio-9p.c >> @@ -1,4 +1,4 @@ >> -/* >> + /* >> * Virtio 9p backend >> * >> * Copyright IBM, Corp. 2010 >> @@ -269,6 +269,11 @@ static int v9fs_do_fsync(V9fsState *s, int fd) >> return s->ops->fsync(&s->ctx, fd); >> } >> >> +static int v9fs_do_statfs(V9fsState *s, V9fsString *path, struct statfs >> *stbuf) >> +{ >> + return s->ops->statfs(&s->ctx, path->data, stbuf); >> +} >> + >> static void v9fs_string_init(V9fsString *str) >> { >> str->data = NULL; >> @@ -1035,11 +1040,10 @@ static void v9fs_fix_path(V9fsString *dst, >> V9fsString *src, int len) >> >> static void v9fs_version(V9fsState *s, V9fsPDU *pdu) >> { >> - int32_t msize; >> V9fsString version; >> size_t offset = 7; >> >> - pdu_unmarshal(pdu, offset, "ds", &msize, &version); >> + pdu_unmarshal(pdu, offset, "ds", &s->msize, &version); >> >> if (!strcmp(version.data, "9P2000.u")) { >> s->proto_version = V9FS_PROTO_2000U; >> @@ -1049,7 +1053,7 @@ static void v9fs_version(V9fsState *s, V9fsPDU *pdu) >> v9fs_string_sprintf(&version, "unknown"); >> } >> >> - offset += pdu_marshal(pdu, offset, "ds", msize, &version); >> + offset += pdu_marshal(pdu, offset, "ds", s->msize, &version); >> complete_pdu(s, pdu, offset); >> >> v9fs_string_free(&version); >> @@ -1304,6 +1308,20 @@ out: >> v9fs_walk_complete(s, vs, err); >> } >> >> +static int32_t get_iounit(V9fsState *s, V9fsString *name) >> +{ >> + struct statfs stbuf; >> + int32_t iounit = 0; >> + >> + >> + if (!v9fs_do_statfs(s, name, &stbuf)) { >> + iounit = stbuf.f_bsize; >> + iounit *= (s->msize - P9_IOHDRSZ)/stbuf.f_bsize; > > If (s->msize - P9_IOHDRSZ) is less than stbuf.f_bsize iounit becomes > zero. See below. > >> + } >> + >> + return iounit; >> +} >> + >> static void v9fs_open_post_opendir(V9fsState *s, V9fsOpenState *vs, int err) >> { >> if (vs->fidp->dir == NULL) { >> @@ -1321,12 +1339,15 @@ out: >> >> static void v9fs_open_post_open(V9fsState *s, V9fsOpenState *vs, int err) >> { >> + int32_t iounit; >> + >> if (vs->fidp->fd == -1) { >> err = -errno; >> goto out; >> } >> >> - vs->offset += pdu_marshal(vs->pdu, vs->offset, "Qd", &vs->qid, 0); >> + iounit = get_iounit(s, &vs->fidp->path); >> + vs->offset += pdu_marshal(vs->pdu, vs->offset, "Qd", &vs->qid, iounit); >> err = vs->offset; >> out: >> complete_pdu(s, vs->pdu, err); >> @@ -1800,11 +1821,16 @@ out: >> >> static void v9fs_post_create(V9fsState *s, V9fsCreateState *vs, int err) >> { >> + int32_t iounit; >> + >> + iounit = get_iounit(s, &vs->fidp->path); >> + >> if (err == 0) { >> v9fs_string_copy(&vs->fidp->path, &vs->fullname); >> stat_to_qid(&vs->stbuf, &vs->qid); >> >> - vs->offset += pdu_marshal(vs->pdu, vs->offset, "Qd", &vs->qid, 0); >> + vs->offset += pdu_marshal(vs->pdu, vs->offset, "Qd", &vs->qid, >> + iounit); >> >> err = vs->offset; >> } >> @@ -2295,23 +2321,25 @@ out: >> qemu_free(vs); >> } >> >> -static int v9fs_do_statfs(V9fsState *s, V9fsString *path, struct statfs >> *stbuf) >> -{ >> - return s->ops->statfs(&s->ctx, path->data, stbuf); >> -} >> - >> static void v9fs_statfs_post_statfs(V9fsState *s, V9fsStatfsState *vs, int >> err) >> { >> + int32_t bsize_factor; >> + >> if (err) { >> err = -errno; >> goto out; >> } >> >> + bsize_factor = (s->msize - P9_IOHDRSZ)/vs->stbuf.f_bsize; >> + if (!bsize_factor) { >> + bsize_factor = 1; >> + } > > Again, if (s->msize - P9_IOHDRSZ) is less than stbuf.f_bsize > bsize_factor becomes zero. The following divisions become divide by > zero!
Yes, I think we should leave iounit alone return it with open/create and handle it as per the 9P protocol..and return whatever the fileserver gives for stat and satatfs. - JV > > Thanks, > Sripathi. > >> vs->v9statfs.f_type = vs->stbuf.f_type; >> vs->v9statfs.f_bsize = vs->stbuf.f_bsize; >> - vs->v9statfs.f_blocks = vs->stbuf.f_blocks; >> - vs->v9statfs.f_bfree = vs->stbuf.f_bfree; >> - vs->v9statfs.f_bavail = vs->stbuf.f_bavail; >> + vs->v9statfs.f_bsize *= bsize_factor; >> + vs->v9statfs.f_blocks = vs->stbuf.f_blocks/bsize_factor; >> + vs->v9statfs.f_bfree = vs->stbuf.f_bfree/bsize_factor; >> + vs->v9statfs.f_bavail = vs->stbuf.f_bavail/bsize_factor; >> vs->v9statfs.f_files = vs->stbuf.f_files; >> vs->v9statfs.f_ffree = vs->stbuf.f_ffree; >> vs->v9statfs.fsid_val = (unsigned int) vs->stbuf.f_fsid.__val[0] | >> diff --git a/hw/virtio-9p.h b/hw/virtio-9p.h >> index 6b3d4a4..9264163 100644 >> --- a/hw/virtio-9p.h >> +++ b/hw/virtio-9p.h >> @@ -72,6 +72,8 @@ enum p9_proto_version { >> #define P9_NOFID (u32)(~0) >> #define P9_MAXWELEM 16 >> >> +#define P9_IOHDRSZ 24 >> + >> typedef struct V9fsPDU V9fsPDU; >> >> struct V9fsPDU >> @@ -156,6 +158,7 @@ typedef struct V9fsState >> uint8_t *tag; >> size_t config_size; >> enum p9_proto_version proto_version; >> + int32_t msize; >> } V9fsState; >> >> typedef struct V9fsCreateState { >> -- >> 1.6.6.1 >> >> >