Corinna Vinschen wrote:
On Nov 30 15:04, Corinna Vinschen wrote:
On Nov 30 13:49, Christian Franke wrote:
Corinna Vinschen wrote:
On Nov 28 22:59, Christian Franke wrote:
...
The attached experimental patch does not fix the lseek() (sorry), but
handles such block devices with fhandler_dev_floppy instead. Tested with
above use cases.
I'm not sure whether this could break access to other /proc/sys block
devices. This would happen if fh->exists() returns virt_blk for devices
which do not support IOCTL_DISK_GET_DRIVE_GEOMETRY* or
IOCTL_DISK_GET_PARTITION_INFO*.
Pushed, becasue it's a nice idea. The above problem shouldn't happen,
in theory, but I'm not sure. virt_blk is generated for devices types
FILE_DEVICE_DISK
FILE_DEVICE_CD_ROM
FILE_DEVICE_VIRTUAL_DISK
FILE_DEVICE_DFS
FILE_DEVICE_NETWORK_FILE_SYSTEM
FILE_DEVICE_DFS or FILE_DEVICE_NETWORK_FILE_SYSTEM might be a problem,
but there should be a way to workaround that, if necessary, isn't it?
Maybe it's a bad idea to treat those as blk devices at all?
Could anything be read from such a node? If yes, treat as character device?
If no and /proc/sys/foo/bar/some/path allows access to /some/path behind
DFS/NFS node /proc/sys/foo/bar, then treat as directory?
This is already the case for SMB shares:
$ ls -ld /proc/sys/DosDevices/X:
lr-------- 1 ... 0 Nov 30 13:10 /proc/sys/DosDevices/X: ->
/proc/sys/Device/LanmanRedirector/;X:..../127.0.0.1/Share
$ ls -lLd /proc/sys/DosDevices/X:
drwxr-xr-x 1 ... 0 Nov 14 09:06 /proc/sys/DosDevices/X:
$ ls -L /proc/sys/DosDevices/X:
... files on this share
...and it's already the case for NFS shares, too:
$ ls -ld /proc/sys/DosDevices/Y:
lr-------- 1 corinna vinschen 0 Nov 30 14:59 /proc/sys/DosDevices/Y: ->
/proc/sys/Device/MRxNfs/;Y:00000000001cb27f/...
$ ls -lLd /proc/sys/DosDevices/Y:
drwxr-xr-x 5 corinna vinschen 41 May 19 2016 /proc/sys/DosDevices/Y:
That means we don't have to handle FILE_DEVICE_NETWORK_FILE_SYSTEM in
the code creating the virt_blk device type at all. I have high hopes
this is the same for DFS, albeit I can't test it...
Oh, right, I just realized that \Device\MRxNfs, as well as
\Device\LanmanRedirector are symlinks pointing below \Device\Mup:
$ ls -l /proc/sys/Device/LanmanRedirector
lr--r--r-- 1 Administrators SYSTEM 0 Nov 30 15:20
/proc/sys/Device/LanmanRedirector -> /proc/sys/Device/Mup/;LanmanRedirector
$ ls -l /proc/sys/Device/MRxNfs
lr--r--r-- 1 Administrators SYSTEM 0 Nov 30 15:20 /proc/sys/Device/MRxNfs ->
/proc/sys/Device/Mup/;MRxNfs
\Device\Mup is a character device and thus the devices below are not
accessible for directory enumeration. I assume it's the same for DFS.
Here I see \Device\Mup as a block device on two systems (cygwin1.dll 3.1.7):
$ ls -l /proc/sys/Device/Mup
brwxrwx--x 1 Administrators SYSTEM 0, 250 Dec 1 16:50 /proc/sys/Device/Mup
Device could be opened for reading, but actual read fails with NTSTATUS
STATUS_INVALID_DEVICE_REQUEST.
Any path which do not exist produce misleading results:
$ ls -l /proc/sys/Device/Mup/no.such.file
crw-rw---- 1 Administrators SYSTEM 0, 250 Dec 1 16:52
/proc/sys/Device/Mup/no.such.file
Thanks,
Christian
