From 9e4320eec5204da851ac95fb7a7e6520c9ccee7d Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Mon, 27 Jan 2020 19:01:19 +0100 Subject: [PATCH 048/116] virtiofsd: Plumb fuse_bufvec through to do_write_buf MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Dr. David Alan Gilbert Message-id: <20200127190227.40942-45-dgilbert@redhat.com> Patchwork-id: 93499 O-Subject: [RHEL-AV-8.2 qemu-kvm PATCH 044/112] virtiofsd: Plumb fuse_bufvec through to do_write_buf Bugzilla: 1694164 RH-Acked-by: Philippe Mathieu-Daudé RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Sergio Lopez Pascual From: "Dr. David Alan Gilbert" Let fuse_session_process_buf_int take a fuse_bufvec * instead of a fuse_buf; and then through to do_write_buf - where in the best case it can pass that straight through to op.write_buf without copying (other than skipping a header). Signed-off-by: Dr. David Alan Gilbert Signed-off-by: Stefan Hajnoczi Reviewed-by: Masayoshi Mizuma Signed-off-by: Dr. David Alan Gilbert (cherry picked from commit 469f9d2fc405b0508e6cf1b4b5bbcadfc82064e5) Signed-off-by: Miroslav Rezanina --- tools/virtiofsd/fuse_i.h | 2 +- tools/virtiofsd/fuse_lowlevel.c | 61 +++++++++++++++++++++++++++-------------- tools/virtiofsd/fuse_virtio.c | 3 +- 3 files changed, 44 insertions(+), 22 deletions(-) diff --git a/tools/virtiofsd/fuse_i.h b/tools/virtiofsd/fuse_i.h index 45995f3..a20854f 100644 --- a/tools/virtiofsd/fuse_i.h +++ b/tools/virtiofsd/fuse_i.h @@ -100,7 +100,7 @@ int fuse_send_reply_iov_nofree(fuse_req_t req, int error, struct iovec *iov, void fuse_free_req(fuse_req_t req); void fuse_session_process_buf_int(struct fuse_session *se, - const struct fuse_buf *buf, + struct fuse_bufvec *bufv, struct fuse_chan *ch); diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c index 95f4db8..7e10995 100644 --- a/tools/virtiofsd/fuse_lowlevel.c +++ b/tools/virtiofsd/fuse_lowlevel.c @@ -1004,11 +1004,12 @@ static void do_write(fuse_req_t req, fuse_ino_t nodeid, const void *inarg) } static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, const void *inarg, - const struct fuse_buf *ibuf) + struct fuse_bufvec *ibufv) { struct fuse_session *se = req->se; - struct fuse_bufvec bufv = { - .buf[0] = *ibuf, + struct fuse_bufvec *pbufv = ibufv; + struct fuse_bufvec tmpbufv = { + .buf[0] = ibufv->buf[0], .count = 1, }; struct fuse_write_in *arg = (struct fuse_write_in *)inarg; @@ -1018,22 +1019,31 @@ static void do_write_buf(fuse_req_t req, fuse_ino_t nodeid, const void *inarg, fi.fh = arg->fh; fi.writepage = arg->write_flags & FUSE_WRITE_CACHE; - fi.lock_owner = arg->lock_owner; - fi.flags = arg->flags; - if (!(bufv.buf[0].flags & FUSE_BUF_IS_FD)) { - bufv.buf[0].mem = PARAM(arg); - } - - bufv.buf[0].size -= - sizeof(struct fuse_in_header) + sizeof(struct fuse_write_in); - if (bufv.buf[0].size < arg->size) { - fuse_log(FUSE_LOG_ERR, "fuse: do_write_buf: buffer size too small\n"); - fuse_reply_err(req, EIO); - return; + if (ibufv->count == 1) { + fi.lock_owner = arg->lock_owner; + fi.flags = arg->flags; + if (!(tmpbufv.buf[0].flags & FUSE_BUF_IS_FD)) { + tmpbufv.buf[0].mem = PARAM(arg); + } + tmpbufv.buf[0].size -= + sizeof(struct fuse_in_header) + sizeof(struct fuse_write_in); + if (tmpbufv.buf[0].size < arg->size) { + fuse_log(FUSE_LOG_ERR, + "fuse: do_write_buf: buffer size too small\n"); + fuse_reply_err(req, EIO); + return; + } + tmpbufv.buf[0].size = arg->size; + pbufv = &tmpbufv; + } else { + /* + * Input bufv contains the headers in the first element + * and the data in the rest, we need to skip that first element + */ + ibufv->buf[0].size = 0; } - bufv.buf[0].size = arg->size; - se->op.write_buf(req, nodeid, &bufv, arg->offset, &fi); + se->op.write_buf(req, nodeid, pbufv, arg->offset, &fi); } static void do_flush(fuse_req_t req, fuse_ino_t nodeid, const void *inarg) @@ -2024,13 +2034,24 @@ static const char *opname(enum fuse_opcode opcode) void fuse_session_process_buf(struct fuse_session *se, const struct fuse_buf *buf) { - fuse_session_process_buf_int(se, buf, NULL); + struct fuse_bufvec bufv = { .buf[0] = *buf, .count = 1 }; + fuse_session_process_buf_int(se, &bufv, NULL); } +/* + * Restriction: + * bufv is normally a single entry buffer, except for a write + * where (if it's in memory) then the bufv may be multiple entries, + * where the first entry contains all headers and subsequent entries + * contain data + * bufv shall not use any offsets etc to make the data anything + * other than contiguous starting from 0. + */ void fuse_session_process_buf_int(struct fuse_session *se, - const struct fuse_buf *buf, + struct fuse_bufvec *bufv, struct fuse_chan *ch) { + const struct fuse_buf *buf = bufv->buf; struct fuse_in_header *in; const void *inarg; struct fuse_req *req; @@ -2108,7 +2129,7 @@ void fuse_session_process_buf_int(struct fuse_session *se, inarg = (void *)&in[1]; if (in->opcode == FUSE_WRITE && se->op.write_buf) { - do_write_buf(req, in->nodeid, inarg, buf); + do_write_buf(req, in->nodeid, inarg, bufv); } else { fuse_ll_ops[in->opcode].func(req, in->nodeid, inarg); } diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c index 635f877..fd588a4 100644 --- a/tools/virtiofsd/fuse_virtio.c +++ b/tools/virtiofsd/fuse_virtio.c @@ -501,7 +501,8 @@ static void *fv_queue_thread(void *opaque) /* TODO! Endianness of header */ /* TODO: Add checks for fuse_session_exited */ - fuse_session_process_buf_int(se, &fbuf, &ch); + struct fuse_bufvec bufv = { .buf[0] = fbuf, .count = 1 }; + fuse_session_process_buf_int(se, &bufv, &ch); if (!qi->reply_sent) { fuse_log(FUSE_LOG_DEBUG, "%s: elem %d no reply sent\n", -- 1.8.3.1