bfs_fuse needs root privs since hrev41258

[luroh]

Before hrev41258, it was possible to mount a Haiku partition in Linux without root privileges.

[idefix]

As far as I can remember, I always had to use sudo to mount a Haiku partition in Ubuntu.

Will look into it...

[idefix]

I tried to mount an partition in Linux (Ubuntu 11.10) as a normal user, but it wouldn't let me:
With hrev41257:

jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ mkdir bfs_fuse_mount
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ ./bfs_fuse_hrev41257 /dev/sda7 bfs_fuse_mount/
bfs: Mount:329: Bad file descriptor
bfs: bfs_mount:172: Bad file descriptor
Error: Mounting FS failed: Bad file descriptor
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ sudo ./bfs_fuse_hrev41257 /dev/sda7 bfs_fuse_mount/
[sudo] password for jeroen: 
bfs: mounted "Build" (root node at 524288, device = /dev/sda7)
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ umount bfs_fuse_mount
umount: /home/jeroen/Builds/Haiku/befs_fuse_bug/bfs_fuse_mount is not in the fstab (and you are not root)
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ sudo umount bfs_fuse_mount
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ 

With hrev43876:

jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ mkdir bfs_fuse_mount
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ ./bfs_fuse_hrev43876 /dev/sda7 bfs_fuse_mount
bfs: Mount:340: Bad file descriptor
bfs: bfs_mount:172: Bad file descriptor
Error: Mounting FS failed: Bad file descriptor
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ sudo ./bfs_fuse_hrev43876 /dev/sda7 bfs_fuse_mount
[sudo] password for jeroen: 
bfs: mounted "Build" (root node at 524288, device = /dev/sda7)
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ umount bfs_fuse_mount
umount: /home/jeroen/Builds/Haiku/befs_fuse_bug/bfs_fuse_mount is not in the fstab (and you are not root)
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ sudo umount bfs_fuse_mount
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ 

When mounting an image, it would let me do it as non-user though.
With hrev41257:

jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ mkdir bfs_fuse_mount
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ ./bfs_fuse_hrev41257 haiku-nightly.image bfs_fuse_mount
bfs: mounted "Haiku" (root node at 131072, device = haiku-nightly.image)
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ umount bfs_fuse_mount
umount: /home/jeroen/Builds/Haiku/befs_fuse_bug/bfs_fuse_mount is not in the fstab (and you are not root)
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ sudo umount bfs_fuse_mount
[sudo] password for jeroen: 
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ 

But not with hrev43876:

jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ mkdir bfs_fuse_mount
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ ./bfs_fuse_hrev43876 haiku-nightly.image bfs_fuse_mount
bfs: mounted "Haiku" (root node at 131072, device = haiku-nightly.image)
fusermount: failed to open /etc/fuse.conf: Permission denied
fusermount: option allow_other only allowed if 'user_allow_other' is set in /etc/fuse.conf
jeroen@Gromit:~/Builds/Haiku/befs_fuse_bug$ 

This is caused by the fuse option allow_other, which is - by default - not allowed when mounting as non-root user.

I created a patch​ that will only set this option when the user is root.

[idefix]

Only set allow_other fuse option when user is root

[luroh]

With patch 0001, I confirm that it is now possible to mount an image without being root.

It still doesn't let me mount my /dev/sda1 Haiku partition as non-root though:

fusermount: failed to open /etc/fuse.conf: Permission denied
fusermount: option blkdev is privileged

That said, due to a broken display, I'm currently unable to test on the exact same hardware and Ubuntu installation I was using when I created this ticket, so I'll have to do some more testing next week once I get that display sorted.

[idefix]

Does it work when you add yourself to the fuse group?

[luroh]

No, but the first row "fusermount: failed to open..." is no longer displayed. I remembered I do have another computer where I am able to mount without being root, and I can confirm that I am not added to the 'fuse' group on that computer.
Mostly for my own reference, I'm attaching an old bfs_fuse binary from that other machine that lets me mount without being root.

[idefix]

The problem is that to let bfs_fuse better integrate with Linux (as a mount helper), some FUSE options had to be added. But most of them only work when you are root.

I added a new patch​ that will only add the FUSE options when the user is root. It should now behave the same as the old bfs_fuse.

[luroh]

Seems to work fine here. Mystery solved, thanks. :)

[idefix]

Good to hear!

[idefix]

Only add FUSE options when user is root (updated commit message)

[mmadia]

Can anyone comment if attachment:0002-Allow-non-root-to-mount-BFS-partition-with-bfs_fuse.patch​ is OK to commit?

[luroh]

Fwiw, the patch still applies cleanly and works fine here on 64-bit Linux (hrev47303, gcc2).

[waddlesplash]

Applied in hrev50364. Thanks (and apologies for the very long delay!)