"Kirill A. Shutemov" <kir...@shutemov.name> writes: > From: "Kirill A. Shutemov" <kirill.shute...@linux.intel.com> > > Currently we have few issues with P9_STATS_GEN: > > - We don't try to read st_gen anything except files or directories, but > still set P9_STATS_GEN bit in st_result_mask. It may mislead client: > we present garbage as valid st_gen. > > - If we failed to get valid st_gen with ENOTTY, we ignore error, but > still set P9_STATS_GEN bit in st_result_mask. > > - If we failed to get valid st_gen with any other errno, we fail > getattr altogether. It's excessive: we block valid client use-cases, > like chdir(2) to non-readable directory with execution bit set. > > The patch fixes these issues and cleanup code a bit. > > Signed-off-by: Kirill A. Shutemov <kirill.shute...@linux.intel.com> > Reviewed-by: Daniel P. Berrange <berra...@redhat.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.ku...@linux.vnet.ibm.com> > --- > hw/9pfs/cofile.c | 4 ---- > hw/9pfs/virtio-9p-handle.c | 8 +++++++- > hw/9pfs/virtio-9p-local.c | 10 ++++++---- > hw/9pfs/virtio-9p-proxy.c | 3 ++- > hw/9pfs/virtio-9p.c | 12 ++++++++++-- > 5 files changed, 25 insertions(+), 12 deletions(-) > > diff --git a/hw/9pfs/cofile.c b/hw/9pfs/cofile.c > index 194c1306c665..2efebf35710f 100644 > --- a/hw/9pfs/cofile.c > +++ b/hw/9pfs/cofile.c > @@ -38,10 +38,6 @@ int v9fs_co_st_gen(V9fsPDU *pdu, V9fsPath *path, mode_t > st_mode, > }); > v9fs_path_unlock(s); > } > - /* The ioctl may not be supported depending on the path */ > - if (err == -ENOTTY) { > - err = 0; > - } > return err; > } > > diff --git a/hw/9pfs/virtio-9p-handle.c b/hw/9pfs/virtio-9p-handle.c > index fe8e0ed19dcc..17002a3d2867 100644 > --- a/hw/9pfs/virtio-9p-handle.c > +++ b/hw/9pfs/virtio-9p-handle.c > @@ -582,6 +582,7 @@ static int handle_unlinkat(FsContext *ctx, V9fsPath *dir, > static int handle_ioc_getversion(FsContext *ctx, V9fsPath *path, > mode_t st_mode, uint64_t *st_gen) > { > +#ifdef FS_IOC_GETVERSION > int err; > V9fsFidOpenState fid_open; > > @@ -590,7 +591,8 @@ static int handle_ioc_getversion(FsContext *ctx, V9fsPath > *path, > * We can get fd for regular files and directories only > */ > if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) { > - return 0; > + errno = ENOTTY; > + return -1; > } > err = handle_open(ctx, path, O_RDONLY, &fid_open); > if (err < 0) { > @@ -599,6 +601,10 @@ static int handle_ioc_getversion(FsContext *ctx, > V9fsPath *path, > err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen); > handle_close(ctx, &fid_open); > return err; > +#else > + errno = ENOTTY; > + return -1; > +#endif > } > > static int handle_init(FsContext *ctx) > diff --git a/hw/9pfs/virtio-9p-local.c b/hw/9pfs/virtio-9p-local.c > index fc93e9e6e8da..df0dbffa7ac4 100644 > --- a/hw/9pfs/virtio-9p-local.c > +++ b/hw/9pfs/virtio-9p-local.c > @@ -1068,8 +1068,8 @@ err_out: > static int local_ioc_getversion(FsContext *ctx, V9fsPath *path, > mode_t st_mode, uint64_t *st_gen) > { > - int err; > #ifdef FS_IOC_GETVERSION > + int err; > V9fsFidOpenState fid_open; > > /* > @@ -1077,7 +1077,8 @@ static int local_ioc_getversion(FsContext *ctx, > V9fsPath *path, > * We can get fd for regular files and directories only > */ > if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) { > - return 0; > + errno = ENOTTY; > + return -1; > } > err = local_open(ctx, path, O_RDONLY, &fid_open); > if (err < 0) { > @@ -1085,10 +1086,11 @@ static int local_ioc_getversion(FsContext *ctx, > V9fsPath *path, > } > err = ioctl(fid_open.fd, FS_IOC_GETVERSION, st_gen); > local_close(ctx, &fid_open); > + return err; > #else > - err = -ENOTTY; > + errno = ENOTTY; > + return -1; > #endif > - return err; > } > > static int local_init(FsContext *ctx) > diff --git a/hw/9pfs/virtio-9p-proxy.c b/hw/9pfs/virtio-9p-proxy.c > index 5f44bb758b35..b57966d9d883 100644 > --- a/hw/9pfs/virtio-9p-proxy.c > +++ b/hw/9pfs/virtio-9p-proxy.c > @@ -1086,7 +1086,8 @@ static int proxy_ioc_getversion(FsContext *fs_ctx, > V9fsPath *path, > * we can get fd for regular files and directories only > */ > if (!S_ISREG(st_mode) && !S_ISDIR(st_mode)) { > - return 0; > + errno = ENOTTY; > + return -1; > } > err = v9fs_request(fs_ctx->private, T_GETVERSION, st_gen, "s", path); > if (err < 0) { > diff --git a/hw/9pfs/virtio-9p.c b/hw/9pfs/virtio-9p.c > index 8cbb8ae32a03..3e51fcd152f8 100644 > --- a/hw/9pfs/virtio-9p.c > +++ b/hw/9pfs/virtio-9p.c > @@ -1080,10 +1080,18 @@ static void v9fs_getattr(void *opaque) > /* fill st_gen if requested and supported by underlying fs */ > if (request_mask & P9_STATS_GEN) { > retval = v9fs_co_st_gen(pdu, &fidp->path, stbuf.st_mode, > &v9stat_dotl); > - if (retval < 0) { > + switch (retval) { > + case 0: > + /* we have valid st_gen: update result mask */ > + v9stat_dotl.st_result_mask |= P9_STATS_GEN; > + break; > + case -EINTR: > + /* request cancelled */ > goto out; > + default: > + /* failed to get st_gen: not fatal, ignore */ > + break; > } > - v9stat_dotl.st_result_mask |= P9_STATS_GEN; > } > retval = pdu_marshal(pdu, offset, "A", &v9stat_dotl); > if (retval < 0) { > -- > 1.8.4.2