From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
To: qemu-devel@nongnu.org, vgoyal@redhat.com, stefanha@redhat.com,
groug@kaod.org
Cc: virtio-fs@redhat.com
Subject: Re: [PATCH v3 02/26] virtiofsd: Don't assume header layout
Date: Thu, 6 May 2021 16:56:50 +0100 [thread overview]
Message-ID: <YJQRwhsY3SNdMLOH@work-vm> (raw)
In-Reply-To: <20210428110100.27757-3-dgilbert@redhat.com>
* Dr. David Alan Gilbert (git) (dgilbert@redhat.com) wrote:
> From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>
> virtiofsd incorrectly assumed a fixed set of header layout in the virt
> queue; assuming that the fuse and write headers were conveniently
> separated from the data; the spec doesn't allow us to take that
> convenience, so fix it up to deal with it the hard way.
>
> Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Queued this 2/26 only
> ---
> tools/virtiofsd/fuse_virtio.c | 94 +++++++++++++++++++++++++++--------
> 1 file changed, 73 insertions(+), 21 deletions(-)
>
> diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c
> index 3e13997406..6dd73c9b72 100644
> --- a/tools/virtiofsd/fuse_virtio.c
> +++ b/tools/virtiofsd/fuse_virtio.c
> @@ -129,18 +129,55 @@ static void fv_panic(VuDev *dev, const char *err)
> * Copy from an iovec into a fuse_buf (memory only)
> * Caller must ensure there is space
> */
> -static void copy_from_iov(struct fuse_buf *buf, size_t out_num,
> - const struct iovec *out_sg)
> +static size_t copy_from_iov(struct fuse_buf *buf, size_t out_num,
> + const struct iovec *out_sg,
> + size_t max)
> {
> void *dest = buf->mem;
> + size_t copied = 0;
>
> - while (out_num) {
> + while (out_num && max) {
> size_t onelen = out_sg->iov_len;
> + onelen = MIN(onelen, max);
> memcpy(dest, out_sg->iov_base, onelen);
> dest += onelen;
> + copied += onelen;
> out_sg++;
> out_num--;
> + max -= onelen;
> }
> +
> + return copied;
> +}
> +
> +/*
> + * Skip 'skip' bytes in the iov; 'sg_1stindex' is set as
> + * the index for the 1st iovec to read data from, and
> + * 'sg_1stskip' is the number of bytes to skip in that entry.
> + *
> + * Returns True if there are at least 'skip' bytes in the iovec
> + *
> + */
> +static bool skip_iov(const struct iovec *sg, size_t sg_size,
> + size_t skip,
> + size_t *sg_1stindex, size_t *sg_1stskip)
> +{
> + size_t vec;
> +
> + for (vec = 0; vec < sg_size; vec++) {
> + if (sg[vec].iov_len > skip) {
> + *sg_1stskip = skip;
> + *sg_1stindex = vec;
> +
> + return true;
> + }
> +
> + skip -= sg[vec].iov_len;
> + }
> +
> + *sg_1stindex = vec;
> + *sg_1stskip = 0;
> + return skip == 0;
> }
>
> /*
> @@ -457,6 +494,7 @@ static void fv_queue_worker(gpointer data, gpointer user_data)
> bool allocated_bufv = false;
> struct fuse_bufvec bufv;
> struct fuse_bufvec *pbufv;
> + struct fuse_in_header inh;
>
> assert(se->bufsize > sizeof(struct fuse_in_header));
>
> @@ -505,14 +543,15 @@ static void fv_queue_worker(gpointer data, gpointer user_data)
> elem->index);
> assert(0); /* TODO */
> }
> - /* Copy just the first element and look at it */
> - copy_from_iov(&fbuf, 1, out_sg);
> + /* Copy just the fuse_in_header and look at it */
> + copy_from_iov(&fbuf, out_num, out_sg,
> + sizeof(struct fuse_in_header));
> + memcpy(&inh, fbuf.mem, sizeof(struct fuse_in_header));
>
> pbufv = NULL; /* Compiler thinks an unitialised path */
> - if (out_num > 2 &&
> - out_sg[0].iov_len == sizeof(struct fuse_in_header) &&
> - ((struct fuse_in_header *)fbuf.mem)->opcode == FUSE_WRITE &&
> - out_sg[1].iov_len == sizeof(struct fuse_write_in)) {
> + if (inh.opcode == FUSE_WRITE &&
> + out_len >= (sizeof(struct fuse_in_header) +
> + sizeof(struct fuse_write_in))) {
> /*
> * For a write we don't actually need to copy the
> * data, we can just do it straight out of guest memory
> @@ -521,15 +560,15 @@ static void fv_queue_worker(gpointer data, gpointer user_data)
> */
> fuse_log(FUSE_LOG_DEBUG, "%s: Write special case\n", __func__);
>
> - /* copy the fuse_write_in header afte rthe fuse_in_header */
> - fbuf.mem += out_sg->iov_len;
> - copy_from_iov(&fbuf, 1, out_sg + 1);
> - fbuf.mem -= out_sg->iov_len;
> - fbuf.size = out_sg[0].iov_len + out_sg[1].iov_len;
> + fbuf.size = copy_from_iov(&fbuf, out_num, out_sg,
> + sizeof(struct fuse_in_header) +
> + sizeof(struct fuse_write_in));
> + /* That copy reread the in_header, make sure we use the original */
> + memcpy(fbuf.mem, &inh, sizeof(struct fuse_in_header));
>
> /* Allocate the bufv, with space for the rest of the iov */
> pbufv = malloc(sizeof(struct fuse_bufvec) +
> - sizeof(struct fuse_buf) * (out_num - 2));
> + sizeof(struct fuse_buf) * out_num);
> if (!pbufv) {
> fuse_log(FUSE_LOG_ERR, "%s: pbufv malloc failed\n",
> __func__);
> @@ -540,24 +579,37 @@ static void fv_queue_worker(gpointer data, gpointer user_data)
> pbufv->count = 1;
> pbufv->buf[0] = fbuf;
>
> - size_t iovindex, pbufvindex;
> - iovindex = 2; /* 2 headers, separate iovs */
> + size_t iovindex, pbufvindex, iov_bytes_skip;
> pbufvindex = 1; /* 2 headers, 1 fusebuf */
>
> + if (!skip_iov(out_sg, out_num,
> + sizeof(struct fuse_in_header) +
> + sizeof(struct fuse_write_in),
> + &iovindex, &iov_bytes_skip)) {
> + fuse_log(FUSE_LOG_ERR, "%s: skip failed\n",
> + __func__);
> + goto out;
> + }
> +
> for (; iovindex < out_num; iovindex++, pbufvindex++) {
> pbufv->count++;
> pbufv->buf[pbufvindex].pos = ~0; /* Dummy */
> pbufv->buf[pbufvindex].flags = 0;
> pbufv->buf[pbufvindex].mem = out_sg[iovindex].iov_base;
> pbufv->buf[pbufvindex].size = out_sg[iovindex].iov_len;
> +
> + if (iov_bytes_skip) {
> + pbufv->buf[pbufvindex].mem += iov_bytes_skip;
> + pbufv->buf[pbufvindex].size -= iov_bytes_skip;
> + iov_bytes_skip = 0;
> + }
> }
> } else {
> /* Normal (non fast write) path */
>
> - /* Copy the rest of the buffer */
> - fbuf.mem += out_sg->iov_len;
> - copy_from_iov(&fbuf, out_num - 1, out_sg + 1);
> - fbuf.mem -= out_sg->iov_len;
> + copy_from_iov(&fbuf, out_num, out_sg, se->bufsize);
> + /* That copy reread the in_header, make sure we use the original */
> + memcpy(fbuf.mem, &inh, sizeof(struct fuse_in_header));
> fbuf.size = out_len;
>
> /* TODO! Endianness of header */
> --
> 2.31.1
>
>
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
next prev parent reply other threads:[~2021-05-06 16:08 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-28 11:00 [PATCH v3 00/26] virtiofs dax patches Dr. David Alan Gilbert (git)
2021-04-28 11:00 ` [PATCH v3 01/26] virtiofs: Fixup printf args Dr. David Alan Gilbert (git)
2021-05-04 14:54 ` Stefan Hajnoczi
2021-05-05 11:06 ` Dr. David Alan Gilbert
2021-05-06 15:56 ` Dr. David Alan Gilbert
2021-04-28 11:00 ` [PATCH v3 02/26] virtiofsd: Don't assume header layout Dr. David Alan Gilbert (git)
2021-05-04 15:12 ` Stefan Hajnoczi
2021-05-06 15:56 ` Dr. David Alan Gilbert [this message]
2021-04-28 11:00 ` [PATCH v3 03/26] DAX: vhost-user: Rework slave return values Dr. David Alan Gilbert (git)
2021-05-04 15:23 ` Stefan Hajnoczi
2021-05-27 15:59 ` Dr. David Alan Gilbert
2021-04-28 11:00 ` [PATCH v3 04/26] DAX: libvhost-user: Route slave message payload Dr. David Alan Gilbert (git)
2021-05-04 15:26 ` Stefan Hajnoczi
2021-04-28 11:00 ` [PATCH v3 05/26] DAX: libvhost-user: Allow popping a queue element with bad pointers Dr. David Alan Gilbert (git)
2021-04-28 11:00 ` [PATCH v3 06/26] DAX subprojects/libvhost-user: Add virtio-fs slave types Dr. David Alan Gilbert (git)
2021-04-29 15:48 ` Dr. David Alan Gilbert
2021-04-28 11:00 ` [PATCH v3 07/26] DAX: virtio: Add shared memory capability Dr. David Alan Gilbert (git)
2021-04-28 11:00 ` [PATCH v3 08/26] DAX: virtio-fs: Add cache BAR Dr. David Alan Gilbert (git)
2021-05-05 12:12 ` Stefan Hajnoczi
2021-05-05 18:59 ` Dr. David Alan Gilbert
2021-04-28 11:00 ` [PATCH v3 09/26] DAX: virtio-fs: Add vhost-user slave commands for mapping Dr. David Alan Gilbert (git)
2021-05-05 14:15 ` Stefan Hajnoczi
2021-05-27 16:57 ` Dr. David Alan Gilbert
2021-04-28 11:00 ` [PATCH v3 10/26] DAX: virtio-fs: Fill in " Dr. David Alan Gilbert (git)
2021-05-05 16:43 ` Stefan Hajnoczi
2021-04-28 11:00 ` [PATCH v3 11/26] DAX: virtiofsd Add cache accessor functions Dr. David Alan Gilbert (git)
2021-04-28 11:00 ` [PATCH v3 12/26] DAX: virtiofsd: Add setup/remove mappings fuse commands Dr. David Alan Gilbert (git)
2021-05-06 15:02 ` Stefan Hajnoczi
2021-04-28 11:00 ` [PATCH v3 13/26] DAX: virtiofsd: Add setup/remove mapping handlers to passthrough_ll Dr. David Alan Gilbert (git)
2021-04-28 11:00 ` [PATCH v3 14/26] DAX: virtiofsd: Wire up passthrough_ll's lo_setupmapping Dr. David Alan Gilbert (git)
2021-04-28 11:00 ` [PATCH v3 15/26] DAX: virtiofsd: Make lo_removemapping() work Dr. David Alan Gilbert (git)
2021-04-28 11:00 ` [PATCH v3 16/26] DAX: virtiofsd: route se down to destroy method Dr. David Alan Gilbert (git)
2021-04-28 11:00 ` [PATCH v3 17/26] DAX: virtiofsd: Perform an unmap on destroy Dr. David Alan Gilbert (git)
2021-04-28 11:00 ` [PATCH v3 18/26] DAX/unmap: virtiofsd: Add VHOST_USER_SLAVE_FS_IO Dr. David Alan Gilbert (git)
2021-05-06 15:12 ` Stefan Hajnoczi
2021-05-27 17:44 ` Dr. David Alan Gilbert
2021-05-06 15:16 ` Stefan Hajnoczi
2021-05-27 17:31 ` Dr. David Alan Gilbert
2021-04-28 11:00 ` [PATCH v3 19/26] DAX/unmap virtiofsd: Add wrappers for VHOST_USER_SLAVE_FS_IO Dr. David Alan Gilbert (git)
2021-04-28 12:53 ` Dr. David Alan Gilbert
2021-04-28 11:00 ` [PATCH v3 20/26] DAX/unmap virtiofsd: Parse unmappable elements Dr. David Alan Gilbert (git)
2021-05-06 15:23 ` Stefan Hajnoczi
2021-05-27 17:56 ` Dr. David Alan Gilbert
2021-04-28 11:00 ` [PATCH v3 21/26] DAX/unmap virtiofsd: Route unmappable reads Dr. David Alan Gilbert (git)
2021-05-06 15:27 ` Stefan Hajnoczi
2021-04-28 11:00 ` [PATCH v3 22/26] DAX/unmap virtiofsd: route unmappable write to slave command Dr. David Alan Gilbert (git)
2021-05-06 15:28 ` Stefan Hajnoczi
2021-04-28 11:00 ` [PATCH v3 23/26] DAX:virtiofsd: implement FUSE_INIT map_alignment field Dr. David Alan Gilbert (git)
2021-04-28 11:00 ` [PATCH v3 24/26] vhost-user-fs: Extend VhostUserFSSlaveMsg to pass additional info Dr. David Alan Gilbert (git)
2021-05-06 15:31 ` Stefan Hajnoczi
2021-05-06 15:32 ` Stefan Hajnoczi
2021-04-28 11:00 ` [PATCH v3 25/26] vhost-user-fs: Implement drop CAP_FSETID functionality Dr. David Alan Gilbert (git)
2021-04-28 11:01 ` [PATCH v3 26/26] virtiofsd: Ask qemu to drop CAP_FSETID if client asked for it Dr. David Alan Gilbert (git)
2021-05-06 15:37 ` Stefan Hajnoczi
2021-05-06 16:02 ` Vivek Goyal
2021-05-10 9:05 ` Stefan Hajnoczi
2021-05-10 15:23 ` Vivek Goyal
2021-05-10 15:32 ` Stefan Hajnoczi
2021-05-27 19:09 ` Dr. David Alan Gilbert
2021-06-10 15:29 ` Dr. David Alan Gilbert
2021-06-10 16:23 ` Stefan Hajnoczi
2021-06-16 12:36 ` Dr. David Alan Gilbert
2021-06-16 15:29 ` Stefan Hajnoczi
2021-06-16 18:35 ` Dr. David Alan Gilbert
2021-04-28 11:27 ` [PATCH v3 00/26] virtiofs dax patches no-reply
2021-05-06 15:37 ` Stefan Hajnoczi
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