tree eb4e6fb6873355a2a96b698aeb371eb058a88c87
parent 8718d36cf99f5acf0f37487557ec25aee54b930b
author Nick Piggin <npiggin@suse.de> 1275566506 +1000
committer Al Viro <viro@zeniv.linux.org.uk> 1275686190 -0400

fix truncate inode time modification breakage

mtime and ctime should be changed only if the file size has actually
changed. Patches changing ext2 and tmpfs from vmtruncate to new truncate
sequence has caused regressions where they always update timestamps.

There is some strange cases in POSIX where truncate(2) must not update
times unless the size has acutally changed, see 6e656be89.

This area is all still rather buggy in different ways in a lot of
filesystems and needs a cleanup and audit (ideally the vfs will provide
a simple attribute or call to direct all filesystems exactly which
attributes to change). But coming up with the best solution will take a
while and is not appropriate for rc anyway.

So fix recent regression for now.

Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>