On Sat, Oct 20, 2018 at 03:26:37PM -0700, Matthew Wilcox wrote: > On Sat, Oct 20, 2018 at 11:09:57PM +0100, Phillip Potter wrote: > > Remove switch statement from ufs_set_de_type function in fs/ufs/util.h > > header and replace with simple assignment. For each case, S_IFx >> 12 > > is equal to DT_x, so in valid cases (mode & S_IFMT) >> 12 should give > > us the correct file type. It is expected that for *nix compatibility > > reasons, the relation between S_IFx and DT_x will not change. For > > cases where the mode is invalid, upper layer validation catches this > > anyway, so this improves readability and arguably performance by > > assigning (mode & S_IFMT) >> 12 directly without any jump table > > or conditional logic. > > Shouldn't we also do this for other filesystems? A quick scan suggests > someone should at least look at xfs, ubifs, squashfs, romfs, ocfs2, > nilfs2, hfsplus, f2fs, ext4, ext2, exofs, coda, cifs & btrfs. Do what for other filesystems? E.g. ext* has the type cached in directory entry - as a straight enum, so encoding is needed. Which we do. ocfs2 is pretty certain to have it in ext*-compatible layout. ubifs stores them in another enum of its own (also handled). XFS - another enum (present on some layout variants), etc. And... CIFS? Seriously? This stuff is about encoding used to cache the file type in directory entry; how the bleeding hell would CIFS _client_ get anywhere near that?
