From: Chris Mason reiserfs_write_full_page does zero bytes in the file past eof, but it may call get_block on those buffers as well. On machines where the page size is larger than the blocksize, this can result in mmaped files incorrectly growing up to a block boundary during writepage. The fix is to avoid calling get_block for any blocks that are entirely past eof Signed-off-by: Chris Mason Signed-off-by: Andrew Morton --- fs/reiserfs/inode.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff -puN fs/reiserfs/inode.c~reiserfs_write_full_page-should-not-get_block-past-eof fs/reiserfs/inode.c --- a/fs/reiserfs/inode.c~reiserfs_write_full_page-should-not-get_block-past-eof +++ a/fs/reiserfs/inode.c @@ -2340,6 +2340,7 @@ static int reiserfs_write_full_page(stru unsigned long end_index = inode->i_size >> PAGE_CACHE_SHIFT; int error = 0; unsigned long block; + sector_t last_block; struct buffer_head *head, *bh; int partial = 0; int nr = 0; @@ -2387,10 +2388,19 @@ static int reiserfs_write_full_page(stru } bh = head; block = page->index << (PAGE_CACHE_SHIFT - s->s_blocksize_bits); + last_block = (i_size_read(inode) - 1) >> inode->i_blkbits; /* first map all the buffers, logging any direct items we find */ do { - if ((checked || buffer_dirty(bh)) && (!buffer_mapped(bh) || - (buffer_mapped(bh) + if (block > last_block) { + /* + * This can happen when the block size is less than + * the page size. The corresponding bytes in the page + * were zero filled above + */ + clear_buffer_dirty(bh); + set_buffer_uptodate(bh); + } else if ((checked || buffer_dirty(bh)) && + (!buffer_mapped(bh) || (buffer_mapped(bh) && bh->b_blocknr == 0))) { /* not mapped yet, or it points to a direct item, search _