Following is the initial test version of case-insensitive support for XFS in Linux. It implements case-insensitivity utilising a Unicode case folding table stored on disk generated from http://www.unicode.org/Public/UNIDATA/CaseFolding.txt As the filesystem stores names as Unicode (UTF-8), the "nls" mount option has been added to support systems not utilising UTF-8 natively. If the nls mount option is not used, it will use the default NLS defined in the kernel's config. To allow case-insensitivity to be a mount option rather than a mkfs option, the hashes stored on disk are always case-folded. This is indicated by the new "unicode" bit in the superblock. This bit also associated with the presence of the case-folding table on disk. With the case-folding table on disk, it allows us to upgrade the table in the future while retaining backwards and forwards compatibility. It also allows special case tables such as Turkic case which is supported in this patch set. The case-insensitive support also installs a couple of dentry_operations for the XFS inodes: hash and compare. Currently, there is a couple of outstanding issues with the dentry cache interaction: - The first lookup if case-mismatched will continue to have the mismatched case in the cache. Not really sure if this is an issue or not. If it is an issue, how should I resolve it? - As above, but with a non-existing lookup, then creating the file with a different case, the first failed lookup will define the case used. I have partially resolved this with a memcpy if the two lengths are the same. How do I fix this if the lengths are different? (TODO's show the location of this problem.) Other TODOs: - support for case-insensitve extended attributes as a separate mount option. - Other xfsprogs updates: xfs_repair, xfs_db - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
