Hello Michal, Recently I'm working with configfs and libusbg. I have been also using FFS with it as it was merged in some recent kernel versions. While using I have experienced some issue while mounting it. Let me describe my it: $ cd /sys/kernel/config/usb_gadget $ mkdir g1 $ mkdir g1/functions/ffs.sdb At this point I'm able to mount using: $ mount sdb -t functionfs /tmp/sdb But if I make a mistake and write: $ mount sbd -t functionfs /tmp/sdb I get: mount: unknown filesystem type 'functionfs' Wow that was quite amazing for me, so I have checked few times /proc/filesystems and loaded modules and all looked fine. So I have used strace and found out that error returned from syscall was -ENODEV. I have started to look why such description is given to this error code. I found out that kernel returns -ENODEV error which when file system type has not been found. I look into code of ffs and found out that ffs_fs_mount() also returns this error if it was unable to acquire given device. I know that this error looks really suitable in this place but it really hurts discoverability in userspace because you don't know where did you make your typo in file system name or in dev name. I have run through few other fs implementations and found out that they all return -ENOENT if given device has not been found. Maybe FFS should follow this convention or maybe convention should be changed? -- Best regards, Krzysztof Opasiak Samsung R&D Institute Poland Samsung Electronics -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
