diff options
| -rw-r--r-- | hw/9pfs/9p.c | 89 |
1 files changed, 70 insertions, 19 deletions
diff --git a/hw/9pfs/9p.c b/hw/9pfs/9p.c index 7be07f2d68..2815257f42 100644 --- a/hw/9pfs/9p.c +++ b/hw/9pfs/9p.c @@ -1705,9 +1705,9 @@ static void coroutine_fn v9fs_walk(void *opaque) int name_idx; V9fsQID *qids = NULL; int i, err = 0; - V9fsPath dpath, path; + V9fsPath dpath, path, *pathes = NULL; uint16_t nwnames; - struct stat stbuf; + struct stat stbuf, fidst, *stbufs = NULL; size_t offset = 7; int32_t fid, newfid; V9fsString *wnames = NULL; @@ -1733,6 +1733,8 @@ static void coroutine_fn v9fs_walk(void *opaque) if (nwnames) { wnames = g_new0(V9fsString, nwnames); qids = g_new0(V9fsQID, nwnames); + stbufs = g_new0(struct stat, nwnames); + pathes = g_new0(V9fsPath, nwnames); for (i = 0; i < nwnames; i++) { err = pdu_unmarshal(pdu, offset, "s", &wnames[i]); if (err < 0) { @@ -1753,39 +1755,85 @@ static void coroutine_fn v9fs_walk(void *opaque) v9fs_path_init(&dpath); v9fs_path_init(&path); + /* + * Both dpath and path initially point to fidp. + * Needed to handle request with nwnames == 0 + */ + v9fs_path_copy(&dpath, &fidp->path); + v9fs_path_copy(&path, &fidp->path); - err = v9fs_co_lstat(pdu, &fidp->path, &stbuf); + /* + * To keep latency (i.e. overall execution time for processing this + * Twalk client request) as small as possible, run all the required fs + * driver code altogether inside the following block. + */ + v9fs_co_run_in_worker({ + if (v9fs_request_cancelled(pdu)) { + err = -EINTR; + break; + } + err = s->ops->lstat(&s->ctx, &dpath, &fidst); + if (err < 0) { + err = -errno; + break; + } + stbuf = fidst; + for (name_idx = 0; name_idx < nwnames; name_idx++) { + if (v9fs_request_cancelled(pdu)) { + err = -EINTR; + break; + } + if (!same_stat_id(&pdu->s->root_st, &stbuf) || + strcmp("..", wnames[name_idx].data)) + { + err = s->ops->name_to_path(&s->ctx, &dpath, + wnames[name_idx].data, &path); + if (err < 0) { + err = -errno; + break; + } + if (v9fs_request_cancelled(pdu)) { + err = -EINTR; + break; + } + err = s->ops->lstat(&s->ctx, &path, &stbuf); + if (err < 0) { + err = -errno; + break; + } + stbufs[name_idx] = stbuf; + v9fs_path_copy(&dpath, &path); + v9fs_path_copy(&pathes[name_idx], &path); + } + } + }); + /* + * Handle all the rest of this Twalk request on main thread ... + */ if (err < 0) { goto out; } - err = stat_to_qid(pdu, &stbuf, &qid); + + err = stat_to_qid(pdu, &fidst, &qid); if (err < 0) { goto out; } + stbuf = fidst; - /* - * Both dpath and path initially poin to fidp. - * Needed to handle request with nwnames == 0 - */ + /* reset dpath and path */ v9fs_path_copy(&dpath, &fidp->path); v9fs_path_copy(&path, &fidp->path); + for (name_idx = 0; name_idx < nwnames; name_idx++) { if (!same_stat_id(&pdu->s->root_st, &stbuf) || - strcmp("..", wnames[name_idx].data)) { - err = v9fs_co_name_to_path(pdu, &dpath, wnames[name_idx].data, - &path); - if (err < 0) { - goto out; - } - - err = v9fs_co_lstat(pdu, &path, &stbuf); - if (err < 0) { - goto out; - } + strcmp("..", wnames[name_idx].data)) + { + stbuf = stbufs[name_idx]; err = stat_to_qid(pdu, &stbuf, &qid); if (err < 0) { goto out; } + v9fs_path_copy(&path, &pathes[name_idx]); v9fs_path_copy(&dpath, &path); } memcpy(&qids[name_idx], &qid, sizeof(qid)); @@ -1821,9 +1869,12 @@ out_nofid: if (nwnames && nwnames <= P9_MAXWELEM) { for (name_idx = 0; name_idx < nwnames; name_idx++) { v9fs_string_free(&wnames[name_idx]); + v9fs_path_free(&pathes[name_idx]); } g_free(wnames); g_free(qids); + g_free(stbufs); + g_free(pathes); } } |