Ihar `Philips` Filipau wrote:
Hi! [ Please CC: me, I'm not subscribed. Yet. ] The problem have beaten me before. And now I have it again. Imaging external hard drive with "proper" file system (proper == supports posix permissions) where files were created by user A and then it (ext. hard drive) was brought to another location/computer and user B tried to read them. Failure. Why? Because Linux preserved permissions on hard drive - though they are already irrelevant on system fs is currently mounted on. And that renders literally all files accessible only by root. What is needed is special mount option to tell file system (*): (1) to ignore permissions when file/directory is read; (2) when file/directory is created it receives automatically "world writable" permissions 0666 (I cannot imaging how to simulate "user friendly" file attribute "read-only", though it seems not relevant to external storage anyway).
it's not just hard drives, I've found badly mastered video DVDs that have written the files to only be readable by the "owner" (UDF supports a normal owner,group,world semantic). Of course they test it in windows which ignores those bits of the fs and everything worked fine, but if one tries to use it in linux, it can only be played as root. As it's a DVD, one has no ability to change the permissions, and one might not even be able to easily extract and copy it to a new disk if its larger than what a DVD+-R can hold (ignoring less common DL disks for now).
My assumption is, if someone is mounting media, it should be assumed he owns the media, and he should be able to disable permission checking for that mount point if he desires. right now there is no way to do that.
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