[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [PATCH v5 1/3] virtiofsd: extract lo_do_open() from lo_open()
From: |
Greg Kurz |
Subject: |
Re: [PATCH v5 1/3] virtiofsd: extract lo_do_open() from lo_open() |
Date: |
Thu, 4 Feb 2021 18:08:05 +0100 |
On Thu, 4 Feb 2021 15:02:06 +0000
Stefan Hajnoczi <stefanha@redhat.com> wrote:
> Both lo_open() and lo_create() have similar code to open a file. Extract
> a common lo_do_open() function from lo_open() that will be used by
> lo_create() in a later commit.
>
> Since lo_do_open() does not otherwise need fuse_req_t req, convert
> lo_add_fd_mapping() to use struct lo_data *lo instead.
>
> Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
> ---
Reviewed-by: Greg Kurz <groug@kaod.org>
> v4:
> * Return positive errno if openat(2) fails in lo_do_open() [Greg]
> ---
> tools/virtiofsd/passthrough_ll.c | 73 ++++++++++++++++++++------------
> 1 file changed, 46 insertions(+), 27 deletions(-)
>
> diff --git a/tools/virtiofsd/passthrough_ll.c
> b/tools/virtiofsd/passthrough_ll.c
> index 5fb36d9407..f14fa5124d 100644
> --- a/tools/virtiofsd/passthrough_ll.c
> +++ b/tools/virtiofsd/passthrough_ll.c
> @@ -459,17 +459,17 @@ static void lo_map_remove(struct lo_map *map, size_t
> key)
> }
>
> /* Assumes lo->mutex is held */
> -static ssize_t lo_add_fd_mapping(fuse_req_t req, int fd)
> +static ssize_t lo_add_fd_mapping(struct lo_data *lo, int fd)
> {
> struct lo_map_elem *elem;
>
> - elem = lo_map_alloc_elem(&lo_data(req)->fd_map);
> + elem = lo_map_alloc_elem(&lo->fd_map);
> if (!elem) {
> return -1;
> }
>
> elem->fd = fd;
> - return elem - lo_data(req)->fd_map.elems;
> + return elem - lo->fd_map.elems;
> }
>
> /* Assumes lo->mutex is held */
> @@ -1651,6 +1651,38 @@ static void update_open_flags(int writeback, int
> allow_direct_io,
> }
> }
>
> +static int lo_do_open(struct lo_data *lo, struct lo_inode *inode,
> + struct fuse_file_info *fi)
> +{
> + char buf[64];
> + ssize_t fh;
> + int fd;
> +
> + update_open_flags(lo->writeback, lo->allow_direct_io, fi);
> +
> + sprintf(buf, "%i", inode->fd);
> + fd = openat(lo->proc_self_fd, buf, fi->flags & ~O_NOFOLLOW);
> + if (fd == -1) {
> + return errno;
> + }
> +
> + pthread_mutex_lock(&lo->mutex);
> + fh = lo_add_fd_mapping(lo, fd);
> + pthread_mutex_unlock(&lo->mutex);
> + if (fh == -1) {
> + close(fd);
> + return ENOMEM;
> + }
> +
> + fi->fh = fh;
> + if (lo->cache == CACHE_NONE) {
> + fi->direct_io = 1;
> + } else if (lo->cache == CACHE_ALWAYS) {
> + fi->keep_cache = 1;
> + }
> + return 0;
> +}
> +
> static void lo_create(fuse_req_t req, fuse_ino_t parent, const char *name,
> mode_t mode, struct fuse_file_info *fi)
> {
> @@ -1691,7 +1723,7 @@ static void lo_create(fuse_req_t req, fuse_ino_t
> parent, const char *name,
> ssize_t fh;
>
> pthread_mutex_lock(&lo->mutex);
> - fh = lo_add_fd_mapping(req, fd);
> + fh = lo_add_fd_mapping(lo, fd);
> pthread_mutex_unlock(&lo->mutex);
> if (fh == -1) {
> close(fd);
> @@ -1892,38 +1924,25 @@ static void lo_fsyncdir(fuse_req_t req, fuse_ino_t
> ino, int datasync,
>
> static void lo_open(fuse_req_t req, fuse_ino_t ino, struct fuse_file_info
> *fi)
> {
> - int fd;
> - ssize_t fh;
> - char buf[64];
> struct lo_data *lo = lo_data(req);
> + struct lo_inode *inode = lo_inode(req, ino);
> + int err;
>
> fuse_log(FUSE_LOG_DEBUG, "lo_open(ino=%" PRIu64 ", flags=%d)\n", ino,
> fi->flags);
>
> - update_open_flags(lo->writeback, lo->allow_direct_io, fi);
> -
> - sprintf(buf, "%i", lo_fd(req, ino));
> - fd = openat(lo->proc_self_fd, buf, fi->flags & ~O_NOFOLLOW);
> - if (fd == -1) {
> - return (void)fuse_reply_err(req, errno);
> - }
> -
> - pthread_mutex_lock(&lo->mutex);
> - fh = lo_add_fd_mapping(req, fd);
> - pthread_mutex_unlock(&lo->mutex);
> - if (fh == -1) {
> - close(fd);
> - fuse_reply_err(req, ENOMEM);
> + if (!inode) {
> + fuse_reply_err(req, EBADF);
> return;
> }
>
> - fi->fh = fh;
> - if (lo->cache == CACHE_NONE) {
> - fi->direct_io = 1;
> - } else if (lo->cache == CACHE_ALWAYS) {
> - fi->keep_cache = 1;
> + err = lo_do_open(lo, inode, fi);
> + lo_inode_put(lo, &inode);
> + if (err) {
> + fuse_reply_err(req, err);
> + } else {
> + fuse_reply_open(req, fi);
> }
> - fuse_reply_open(req, fi);
> }
>
> static void lo_release(fuse_req_t req, fuse_ino_t ino,
- [PATCH v5 0/3] virtiofsd: prevent opening of special files (CVE-2020-35517), Stefan Hajnoczi, 2021/02/04
- [PATCH v5 1/3] virtiofsd: extract lo_do_open() from lo_open(), Stefan Hajnoczi, 2021/02/04
- Re: [PATCH v5 1/3] virtiofsd: extract lo_do_open() from lo_open(),
Greg Kurz <=
- [PATCH v5 2/3] virtiofsd: optionally return inode pointer from lo_do_lookup(), Stefan Hajnoczi, 2021/02/04
- [PATCH v5 3/3] virtiofsd: prevent opening of special files (CVE-2020-35517), Stefan Hajnoczi, 2021/02/04
- Re: [PATCH v5 0/3] virtiofsd: prevent opening of special files (CVE-2020-35517), no-reply, 2021/02/04
- Re: [PATCH v5 0/3] virtiofsd: prevent opening of special files (CVE-2020-35517), Dr. David Alan Gilbert, 2021/02/04