Messages in this thread Patch in this message |  | | From | Sergey Alirzaev <> | Subject | [PATCH 1/2] 9pnet: allow making incomplete read requests | Date | Wed, 5 Feb 2020 03:34:56 +0300 |
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A user doesn't necessarily want to wait for all the requested data to be available, since the waiting time is unbounded.
Signed-off-by: Sergey Alirzaev <l29ah@cock.li> --- include/net/9p/client.h | 2 + net/9p/client.c | 133 ++++++++++++++++++++++------------------ 2 files changed, 76 insertions(+), 59 deletions(-)
diff --git a/include/net/9p/client.h b/include/net/9p/client.h index acc60d8a3b3b..f6c890e94f87 100644 --- a/include/net/9p/client.h +++ b/include/net/9p/client.h @@ -200,6 +200,8 @@ int p9_client_fsync(struct p9_fid *fid, int datasync); int p9_client_remove(struct p9_fid *fid); int p9_client_unlinkat(struct p9_fid *dfid, const char *name, int flags); int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err); +int p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to, + int *err); int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err); int p9_client_readdir(struct p9_fid *fid, char *data, u32 count, u64 offset); int p9dirent_read(struct p9_client *clnt, char *buf, int len, diff --git a/net/9p/client.c b/net/9p/client.c index 1d48afc7033c..186f5b44aa01 100644 --- a/net/9p/client.c +++ b/net/9p/client.c @@ -1548,83 +1548,98 @@ EXPORT_SYMBOL(p9_client_unlinkat); int p9_client_read(struct p9_fid *fid, u64 offset, struct iov_iter *to, int *err) +{ + int total = 0; + *err = 0; + + while (iov_iter_count(to)) { + int count; + + count = p9_client_read_once(fid, offset, to, err); + if (!count || *err) + break; + offset += count; + total += count; + } + return total; +} +EXPORT_SYMBOL(p9_client_read); + +int +p9_client_read_once(struct p9_fid *fid, u64 offset, struct iov_iter *to, + int *err) { struct p9_client *clnt = fid->clnt; struct p9_req_t *req; int total = 0; - *err = 0; + int count = iov_iter_count(to); + int rsize, non_zc = 0; + char *dataptr; + *err = 0; p9_debug(P9_DEBUG_9P, ">>> TREAD fid %d offset %llu %d\n", fid->fid, (unsigned long long) offset, (int)iov_iter_count(to)); - while (iov_iter_count(to)) { - int count = iov_iter_count(to); - int rsize, non_zc = 0; - char *dataptr; + rsize = fid->iounit; + if (!rsize || rsize > clnt->msize - P9_IOHDRSZ) + rsize = clnt->msize - P9_IOHDRSZ; - rsize = fid->iounit; - if (!rsize || rsize > clnt->msize-P9_IOHDRSZ) - rsize = clnt->msize - P9_IOHDRSZ; + if (count < rsize) + rsize = count; - if (count < rsize) - rsize = count; + /* Don't bother zerocopy for small IO (< 1024) */ + if (clnt->trans_mod->zc_request && rsize > 1024) { + /* response header len is 11 + * PDU Header(7) + IO Size (4) + */ + req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize, + 0, 11, "dqd", fid->fid, + offset, rsize); + } else { + non_zc = 1; + req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, + rsize); + } + if (IS_ERR(req)) { + *err = PTR_ERR(req); + return total; + } - /* Don't bother zerocopy for small IO (< 1024) */ - if (clnt->trans_mod->zc_request && rsize > 1024) { - /* - * response header len is 11 - * PDU Header(7) + IO Size (4) - */ - req = p9_client_zc_rpc(clnt, P9_TREAD, to, NULL, rsize, - 0, 11, "dqd", fid->fid, - offset, rsize); - } else { - non_zc = 1; - req = p9_client_rpc(clnt, P9_TREAD, "dqd", fid->fid, offset, - rsize); - } - if (IS_ERR(req)) { - *err = PTR_ERR(req); - break; - } + *err = p9pdu_readf(&req->rc, clnt->proto_version, + "D", &count, &dataptr); + if (*err) { + trace_9p_protocol_dump(clnt, &req->rc); + p9_tag_remove(clnt, req); + return total; + } + if (rsize < count) { + pr_err("bogus RREAD count (%d > %d)\n", count, rsize); + count = rsize; + } - *err = p9pdu_readf(&req->rc, clnt->proto_version, - "D", &count, &dataptr); - if (*err) { - trace_9p_protocol_dump(clnt, &req->rc); - p9_tag_remove(clnt, req); - break; - } - if (rsize < count) { - pr_err("bogus RREAD count (%d > %d)\n", count, rsize); - count = rsize; - } + p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count); + if (!count) { + p9_tag_remove(clnt, req); + return total; + } - p9_debug(P9_DEBUG_9P, "<<< RREAD count %d\n", count); - if (!count) { - p9_tag_remove(clnt, req); - break; - } + if (non_zc) { + int n = copy_to_iter(dataptr, count, to); - if (non_zc) { - int n = copy_to_iter(dataptr, count, to); - total += n; - offset += n; - if (n != count) { - *err = -EFAULT; - p9_tag_remove(clnt, req); - break; - } - } else { - iov_iter_advance(to, count); - total += count; - offset += count; + total += n; + if (n != count) { + *err = -EFAULT; + p9_tag_remove(clnt, req); + return total; } - p9_tag_remove(clnt, req); + } else { + iov_iter_advance(to, count); + total += count; } + p9_tag_remove(clnt, req); return total; } -EXPORT_SYMBOL(p9_client_read); +EXPORT_SYMBOL(p9_client_read_once); int p9_client_write(struct p9_fid *fid, u64 offset, struct iov_iter *from, int *err) -- 2.25.0
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