On Wed, Oct 10, 2018 at 09:12:46PM -0700, Darrick J. Wong wrote: > From: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > > File range remapping, if allowed to run past the destination file's EOF, > is an optimization on a regular file write. Regular file writes that > extend the file length are subject to various constraints which are not > checked by range cloning. > > This is a correctness problem because we're never allowed to touch > ranges that the page cache can't support (s_maxbytes); we're not > supposed to deal with large offsets (MAX_NON_LFS) if O_LARGEFILE isn't > set; and we must obey resource limits (RLIMIT_FSIZE). > > Therefore, add these checks to the new generic_remap_checks function so > that we curtail unexpected behavior. > > Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx> > Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx> Looks good, Reviewed-by: Christoph Hellwig <hch@xxxxxx>
