> > We're already calling truncate_pagecache_range() before we attempt to > do any actual job so there is not need to truncate pagecache once more > using truncate_setsize() after we're finished. > > Remove truncate_setsize() and replace it just with i_size_write() note > that we're holding appropriate locks. > > Signed-off-by: Lukas Czerner <lczerner@xxxxxxxxxx> Hi Lukas. I added this code by getting rewiew from Hugh. Plz see the disscusion beween Hugh and Dave. Hugh: But your case is different: collapse is much closer to truncation, and if you do not unmap the private COW'ed pages, then pages left behind beyond the EOF will break the spec that requires SIGBUS when touching there, and pages within EOF will be confusingly derived from file data now belonging to another offset or none (move these pages within the user address space? no, I don't think anon_vmas would allow that, and there may be no right place to move them). Dave: See above - we never leave pages beyond the new EOF because setting the new EOF is a truncate operation that calls truncate_setsize(inode, newsize). Hugh: Right, thanks, I now see the truncate_setsize() in the xfs case - though not in the ext4 case, which looks as if it's just doing an i_size_write() afterwards. Dave: So that's a bug in the ext4 code ;) truncate_setsize is not needed in case Hugh pointed out ? Thanks! -- 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
