For reading through a directory stream with tolerable performance, we'll
have to call FUSE_READDIRPLUS each time with such a buffer that can
deliver a good number of variable size records
(VIRTIO_FS_FUSE_DIRENTPLUS_RESPONSE elements). Every time we'll do that,
we'll turn the whole bunch into an array of EFI_FILE_INFOs immediately.
EFI_FILE_PROTOCOL.Read() invocations (on directories) will be served from
this EFI_FILE_INFO cache.
Add the fields for the EFI_FILE_INFO cache to VIRTIO_FS_FILE:
- initialize them in Open() and OpenVolume(),
- release the cache in Close() and Delete(),
- also release the cache when the directory is rewound, in SetPosition().
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20201216211125.19496-36-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Using the functions introduced previously, we can now implement
VirtioFsSimpleFileGetPosition() and VirtioFsSimpleFileSetPosition().
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20201216211125.19496-32-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
With the help of the VirtioFsFuseOpenDir() and
VirtioFsFuseReleaseFileOrDir() functions introduced previously, we can now
open and close the root directory. So let's implement
EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.OpenVolume().
OpenVolume() creates a new EFI_FILE_PROTOCOL object -- a reference to the
root directory of the filesystem. Thus, we have to start tracking
references to EFI_SIMPLE_FILE_SYSTEM_PROTOCOL, lest we unbind the
virtio-fs device while files are open.
There are two methods that release an EFI_FILE_PROTOCOL object: the
Close() and the Delete() member functions. In particular, they are not
allowed to fail with regard to resource management -- they must release
resources unconditionally. Thus, for rolling back the resource accounting
that we do in EFI_SIMPLE_FILE_SYSTEM_PROTOCOL.OpenVolume(), we have to
implement the first versions of EFI_FILE_PROTOCOL.Close() and
EFI_FILE_PROTOCOL.Delete() in this patch as well.
With this patch applied, the UEFI shell can enter the root directory of
the Virtio Filesystem (such as with the "FS3:" shell command), and the
"DIR" shell command exercises FUSE_OPENDIR and FUSE_RELEASEDIR, according
to the virtiofsd log. The "DIR" command reports the root directory as if
it were empty; probably because at this time, we only allow the shell to
open and to close the root directory, but not to read it.
Cc: Ard Biesheuvel <ard.biesheuvel@arm.com>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=3097
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Message-Id: <20201216211125.19496-12-lersek@redhat.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@arm.com>
Laszlo Ersek