Depending on my local Windows user account, drives are mounted read-only

[daladim]

Hi,
Thanks for your great work.

I have read-only issues, something similar to what I read in #7.
It turns out that, if I connect a network drive (through the Explorer UI) from my usual account (XPS\Jérôme), my drive is read-only.
If I connect from another account (XPS\sshuser), my drive is perfectly read-write enabled.
Would there be a bug when the local Windows username has diacritics, or non-ASCII characters?

Here is a bit of details. Coming from the Linux world, I am afraid these will not be very precise and/or informative. I am still learning the Windows internals :D

• My two accounts are "local", i.e. they are not mapped to a Microsoft account and e-mail address.
  • XPS\Jérôme is an "Administrator" account
  • XPS\sshuser is not an "Administrator" account
• I have Windows 10 (build 1909)
• I always mount drives via the Explorer GUI (This PC > Map Network Drive). I type \\sshfs\jerome@my.host.com (jeromebeing, of course, my remote Linux username)
• When mounted from XPS\Jérôme, I can successfully read the files, but not write them. I think that my files are owned by SYSTEM (since trying to delete one, makes a "you need a permission form system" dialog appear (I tried to translate it from French, the actual English phrase may be different)). Feel free to provide a more accurate way of knowing, I'd be happy to learn one.
• When mounted from XPS\sshuser, I can read/write/create/delete as expected.
• When mounted from XPS\sshuser, then changed Windows user to XPS\Jérôme (without logging out from sshuser), I still can see the drive, as read-only. Trying to delete a file make a "you need a permission from sshuser" dialog appear.
• The task manager is not very informative, the command line shows ssh.exe, sshfs.exe, and sshfs-win.exe have not been invoked with specific arguments explicitely related to my Windows usernames (other than \sshfs\jerome@my.host.com)

Do you have any idea?
As I am new to Windows, I am afraid it will be hard for me to make a merge request...but if you give me specific directions, I can try!

[billziss-gh]

Can you please do the following for me when running under the XPS\Jérôme account:

• Change to the WinFsp bin directory (likely C:\Program Files (x86)\WinFsp\bin).
• Type the command fsptool-x64.exe id and report its output.

[daladim]

Here is the ouput when I am using the XPS\Jérôme account:

c:\Program Files (x86)\WinFsp\bin>fsptool-x64.exe id
User=S-1-5-21-390629839-2561044350-2268284759-1002(XPS\JÚr¶me) (uid=197610)
Owner=S-1-5-21-390629839-2561044350-2268284759-1002(XPS\JÚr¶me) (uid=197610)
Group=S-1-5-21-390629839-2561044350-2268284759-513(XPS\Aucun) (gid=197121)

("Aucun" is the French for "None")

And here it is when I run it under the XPS\sshuser account:

c:\Program Files (x86)\WinFsp\bin>fsptool-x64.exe id
User=S-1-5-21-390629839-2561044350-2268284759-1007(XPS\sshuser) (uid=197615)
Owner=S-1-5-21-390629839-2561044350-2268284759-1007(XPS\sshuser) (uid=197615)
Group=S-1-5-21-390629839-2561044350-2268284759-513(XPS\Aucun) (gid=197121)

Thanks. Please tell me in case you'd like me to do something else to debug this issue.

[billziss-gh]

Thank you. I asked you to do this, because I suspected that the problem was that the Owner and Group ID were the same. That does not seem to be the case for either one of your accounts.

So this may well be a problem with the name containing non-ASCII characters. Perhaps some layer (and there are many in SSHFS-Win) mangles the name, which results in reduced permissions.

Let's try another experiment. Using the same tool fsptool-x64.exe find a file that is read-only under the XPS\Jérôme account and read-write under the XPS\sshuser account and try the command (for both accounts on the same file):

> fsptool-x64.exe perm X:\FULL\PATH\TO\FILE

(Replace the X:\FULL\PATH\TO\FILE with the full path to your file.)

[daladim]

this comment is off-topic I guess

Hi, thanks for your comment.
I created C:\Test\test-file.txt, and made a complete Frankenstein out of its permissions. I went in the file properties > Security tab, then removed all the inherited rules (for "authenticated users", for "administrators", etc.) and added two explicit rules for XPS\Jérôme and for XPS\sshuser instead.

"Autoriser" is "grant", "Refuser" is "deny", "Lecture et exécution" is "read and execute", "écriture" is "write".
I am not sure this case is likely to happen on a real-life file. Would you prefer I change the permissions of a different file, or in a different way?

Anyway, with this file, here is what I have:

c:\Program Files (x86)\WinFsp\bin>fsptool-x64.exe perm C:\Test\test-file.txt
O:S-1-5-21-390629839-2561044350-2268284759-1007G:S-1-5-21-390629839-2561044350-2268284759-513D:PAI(A;;0x1200a9;;;S-1-5-21-390629839-2561044350-2268284759-1002)(A;;FA;;;S-1-5-21-390629839-2561044350-2268284759-1007) (perm=197615:197121:0700)

[daladim]

If that helps, I have installed MinGW MSYS (version 2013072300)
When I run it, I have nasty encoding issues with my username.
FWIW, I have run whoami and id, maybe it helps.

Tell me in case you want me to build and run something that calls getpwnam (since I think that is what sshfs-win.c uses internally)

[daladim]

Sorry, I did not understand what you meant by a read-write file for sshuser and read-only for Jérôme (that's wide I have hidden the 5th comment as off-topic).

I have made a new attempt with a SSHFS mount (which is what you meant, I assume).

• Graphical login as sshuser.
• In the explorer > This PC > Map Network Drive, I mount \sshfs\jerome@my.host.com as Z:
• From sshuser's explorer window, I browse to Z:, create a new folder Z:\sshfs with a file into it, and a file Z:\test-sshfs.txt with some content. Now I have

Z:\
Z:\a-folder-that-existed-before\
Z:\sshfs\
Z:\a-file-that-existed-before
Z:\test-sshfs.txt

• I switch users to log in as Jérôme (leaving the sshuser account open "in the background").
• I can browse to Z:, see its content and open most of the files and folders.
  However, I cannot open Z:\sshfs (the double-click has no effect) nor open the file Z:\test-sshfs.txt (Notepad complains: "You are not authorized to open this file. Ask the file's owner or an administrator to get this permission").
  Here is the folder from my Linux box:

ssh jerome@my.host.com
$ pwd
/home/jerome
$ ll
-rw-r--r--  1 jerome jerome  831 Jun  9  2019 a-file-that-existed-before
drwxr-xr-x  6 jerome jerome 4.0K Mar 29 19:51 a-folder-that-existed-before
drwx------  2 jerome jerome 4.0K Apr  3 10:26 sshfs
-rwx------  1 jerome jerome    7 Apr  3 10:27 test-sshfs.txt

Maybe it should be a different issue, but the files and folders created through SSHFS do not have "group" and "other" permissions set.

• Anyway, here is fsptool's output (run from Jérôme's account if that matters)

C:\Program Files (x86)\WinFsp\bin>fsptool-x64.exe perm Z:\
O:S-1-5-21-390629839-2561044350-2268284759-1007G:S-1-5-21-390629839-2561044350-2268284759-513D:P(A;;FA;;;S-1-5-21-390629839-2561044350-2268284759-1007)(A;;0x1200a9;;;S-1-5-21-390629839-2561044350-2268284759-513)(A;;0x1200a9;;;WD) (perm=197615:197121:0755)

C:\Program Files (x86)\WinFsp\bin>fsptool-x64.exe perm Z:\a-folder-that-existed-before
O:S-1-5-21-390629839-2561044350-2268284759-1007G:S-1-5-21-390629839-2561044350-2268284759-513D:P(A;;FA;;;S-1-5-21-390629839-2561044350-2268284759-1007)(A;;0x1200a9;;;S-1-5-21-390629839-2561044350-2268284759-513)(A;;0x1200a9;;;WD) (perm=197615:197121:0755)

C:\Program Files (x86)\WinFsp\bin>fsptool-x64.exe perm Z:\a-file-that-existed-before
O:S-1-5-21-390629839-2561044350-2268284759-1007G:S-1-5-21-390629839-2561044350-2268284759-513D:P(A;;0x1f019f;;;S-1-5-21-390629839-2561044350-2268284759-1007)(A;;FR;;;S-1-5-21-390629839-2561044350-2268284759-513)(A;;FR;;;WD) (perm=197615:197121:0644)

C:\Program Files (x86)\WinFsp\bin>fsptool-x64.exe perm Z:\sshfs
O:S-1-5-21-390629839-2561044350-2268284759-1007G:S-1-5-21-390629839-2561044350-2268284759-513D:P(A;;FA;;;S-1-5-21-390629839-2561044350-2268284759-1007)(A;;0x120088;;;S-1-5-21-390629839-2561044350-2268284759-513)(A;;0x120088;;;WD) (perm=197615:197121:0700)

C:\Program Files (x86)\WinFsp\bin>fsptool-x64.exe perm Z:\test-sshfs.txt
O:S-1-5-21-390629839-2561044350-2268284759-1007G:S-1-5-21-390629839-2561044350-2268284759-513D:P(A;;0x1f01bf;;;S-1-5-21-390629839-2561044350-2268284759-1007)(A;;0x120088;;;S-1-5-21-390629839-2561044350-2268284759-513)(A;;0x120088;;;WD) (perm=197615:197121:0700)

[daladim]

Hi @billziss-gh, would you hve any follow-up to this issue?
Is there anything I could try or help with? Or is there any idea you would like to share, that I could try to investigate/debug (in case I manage to build and run from code)?
Thanks