When using 'real' file systems on removable storage devices such as hard disks or usb sticks people quickly face the problem that their Linux users have different uids on different machines. Therefore one cannot modify or even read files created on a different machine without running chown as root or storing everything with mode 777. Simple file systems such as vfat don't have that problem as they don't store file ownership information and one can pass the uid files should belong to as mount option. The following three patches implement the uid (and gid) mount option for ext2, ext3 and ext4 to make them actually useful on removable media. If a file system is mounted with the uid option all files appear to be owned by the specified uid. Only newly created files actually end up with that uid as owner on disk though. Ownership of existing files cannot be changed permanently if the uid option was specified. Optionally a second uid (diskuid) can be specified. This one is actually written to the file system then. Useful if the filesytem is also used on a system that does not support the uid option. The feature can be used in two ways. Firstly via fstab by having the admin add 'uid=useruid' in the fs_mntops column in addition to the 'user' or 'users' option. Secondly via e.g. udisks which would automatically pass the uid of the calling user as option. Ludwig Nussel (3): implement uid and gid mount options for ext2 implement uid and gid mount options for ext3 implement uid and gid mount options for ext4 Documentation/filesystems/ext2.txt | 9 ++++ Documentation/filesystems/ext3.txt | 9 ++++ Documentation/filesystems/ext4.txt | 9 ++++ fs/ext2/ext2.h | 8 +++ fs/ext2/inode.c | 48 +++++++++++++----- fs/ext2/super.c | 95 +++++++++++++++++++++++++++++++++++- fs/ext3/ext3.h | 8 +++ fs/ext3/inode.c | 54 ++++++++++++++------ fs/ext3/super.c | 95 +++++++++++++++++++++++++++++++++++- fs/ext4/ext4.h | 4 ++ fs/ext4/inode.c | 52 ++++++++++++++------ fs/ext4/super.c | 87 ++++++++++++++++++++++++++++++++- 12 Dateien geändert, 433 Zeilen hinzugefügt(+), 45 Zeilen entfernt(-) -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
