From a579121f94aba4e8bad1a121a0fad050d6925296 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Tue, 27 Nov 2018 11:01:43 -0800 Subject: [PATCH] xfs: fix PAGE_MASK usage in xfs_free_file_space In commit e53c4b598, I *tried* to teach xfs to force writeback when we fzero/fpunch right up to EOF so that if EOF is in the middle of a page, the post-EOF part of the page gets zeroed before we return to userspace. Unfortunately, I missed the part where PAGE_MASK is ~(PAGE_SIZE - 1), which means that we totally fail to zero if we're fpunching and EOF is within the first page. Worse yet, the same PAGE_MASK thinko plagues the filemap_write_and_wait_range call, so we'd initiate writeback of the entire file, which (mostly) masked the thinko. Drop the tricky PAGE_MASK and replace it with correct usage of PAGE_SIZE and the proper rounding macros. Fixes: e53c4b598 ("xfs: ensure post-EOF zeroing happens after zeroing part of a file") Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner Reviewed-by: Christoph Hellwig --- fs/xfs/xfs_bmap_util.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c index 404e581f1ea1..1ee8c5539fa4 100644 --- a/fs/xfs/xfs_bmap_util.c +++ b/fs/xfs/xfs_bmap_util.c @@ -1126,9 +1126,9 @@ xfs_free_file_space( * page could be mmap'd and iomap_zero_range doesn't do that for us. * Writeback of the eof page will do this, albeit clumsily. */ - if (offset + len >= XFS_ISIZE(ip) && ((offset + len) & PAGE_MASK)) { + if (offset + len >= XFS_ISIZE(ip) && offset_in_page(offset + len) > 0) { error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, - (offset + len) & ~PAGE_MASK, LLONG_MAX); + round_down(offset + len, PAGE_SIZE), LLONG_MAX); } return error; -- 2.30.2