Re: [PULL 10/28] export/fuse: Pass default_permissions for mount

[Vladimir Sementsov-Ogievskiy]

09.07.2021 15:50, Kevin Wolf wrote:
> From: Max Reitz <mreitz@redhat.com>
>
> We do not do any permission checks in fuse_open(), so let the kernel do
> them.  We already let fuse_getattr() report the proper UNIX permissions,
> so this should work the way we want.
>
> This causes a change in 308's reference output, because now opening a
> non-writable export with O_RDWR fails already, instead of only actually
> attempting to write to it.  (That is an improvement.)
>
> Signed-off-by: Max Reitz <mreitz@redhat.com>
> Message-Id: <20210625142317.271673-2-mreitz@redhat.com>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   block/export/fuse.c        | 8 ++++++--
>   tests/qemu-iotests/308     | 3 ++-
>   tests/qemu-iotests/308.out | 2 +-
>   3 files changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/block/export/fuse.c b/block/export/fuse.c
> index 38f74c94da..d0b88e8f80 100644
> --- a/block/export/fuse.c
> +++ b/block/export/fuse.c
> @@ -153,8 +153,12 @@ static int setup_fuse_export(FuseExport *exp, const char 
> *mountpoint,
>       struct fuse_args fuse_args;
>       int ret;
>   
> -    /* Needs to match what fuse_init() sets.  Only max_read must be supplied. */
> -    mount_opts = g_strdup_printf("max_read=%zu", FUSE_MAX_BOUNCE_BYTES);
> +    /*
> +     * max_read needs to match what fuse_init() sets.
> +     * max_write need not be supplied.
> +     */
> +    mount_opts = g_strdup_printf("max_read=%zu,default_permissions",
> +                                 FUSE_MAX_BOUNCE_BYTES);
>   
>       fuse_argv[0] = ""; /* Dummy program name */
>       fuse_argv[1] = "-o";
> diff --git a/tests/qemu-iotests/308 b/tests/qemu-iotests/308
> index f122065d0f..11c28a75f2 100755
> --- a/tests/qemu-iotests/308
> +++ b/tests/qemu-iotests/308
> @@ -215,7 +215,8 @@ echo '=== Writable export ==='
>   fuse_export_add 'export-mp' "'mountpoint': '$EXT_MP', 'writable': true"
>   
>   # Check that writing to the read-only export fails
> -$QEMU_IO -f raw -c 'write -P 42 1M 64k' "$TEST_IMG" | _filter_qemu_io
> +$QEMU_IO -f raw -c 'write -P 42 1M 64k' "$TEST_IMG" 2>&1 \
> +    | _filter_qemu_io | _filter_testdir | _filter_imgfmt
>   
>   # But here it should work
>   $QEMU_IO -f raw -c 'write -P 42 1M 64k' "$EXT_MP" | _filter_qemu_io
> diff --git a/tests/qemu-iotests/308.out b/tests/qemu-iotests/308.out
> index 466e7e0267..0e9420645f 100644
> --- a/tests/qemu-iotests/308.out
> +++ b/tests/qemu-iotests/308.out
> @@ -91,7 +91,7 @@ virtual size: 0 B (0 bytes)
>                 'mountpoint': 'TEST_DIR/t.IMGFMT.fuse', 'writable': true
>             } }
>   {"return": {}}
> -write failed: Permission denied
> +qemu-io: can't open device TEST_DIR/t.IMGFMT: Could not open 
> 'TEST_DIR/t.IMGFMT': Permission denied
>   wrote 65536/65536 bytes at offset 1048576
>   64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
>   wrote 65536/65536 bytes at offset 1048576

Hi!

308 test fails for me now:

308   fail       [16:02:49] [16:02:53]   3.5s   (last: 3.7s)  output mismatch 
(see 308.out.bad)
--- /work/src/qemu/master/tests/qemu-iotests/308.out
+++ 308.out.bad
@@ -91,7 +91,7 @@
               'mountpoint': 'TEST_DIR/t.IMGFMT.fuse', 'writable': true
           } }
 {"return": {}}
-qemu-io: can't open device TEST_DIR/t.IMGFMT: Could not open 
'TEST_DIR/t.IMGFMT': Permission denied
+write failed: Permission denied
 wrote 65536/65536 bytes at offset 1048576
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 wrote 65536/65536 bytes at offset 1048576
Failures: 308
Failed 1 of 1 iotests


And bisect points to exactly this commit.

Should it somehow depend on environment?


--
Best regards,
Vladimir