From 7684e2c4384d5d1f884b01ab8bff2369e4db0bff Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Thu, 17 Oct 2019 13:12:01 -0700 Subject: iomap: iomap that extends beyond EOF should be marked dirty When doing a direct IO that spans the current EOF, and there are written blocks beyond EOF that extend beyond the current write, the only metadata update that needs to be done is a file size extension. However, we don't mark such iomaps as IOMAP_F_DIRTY to indicate that there is IO completion metadata updates required, and hence we may fail to correctly sync file size extensions made in IO completion when O_DSYNC writes are being used and the hardware supports FUA. Hence when setting IOMAP_F_DIRTY, we need to also take into account whether the iomap spans the current EOF. If it does, then we need to mark it dirty so that IO completion will call generic_write_sync() to flush the inode size update to stable storage correctly. Fixes: 3460cac1ca76 ("iomap: Use FUA for pure data O_DSYNC DIO writes") Signed-off-by: Dave Chinner Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong [darrick: removed the ext4 part; they'll handle it separately] Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_iomap.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'fs/xfs') diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index f780e223b118..32993c2acbd9 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -1049,6 +1049,13 @@ xfs_file_iomap_begin( trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap); out_finish: + /* + * Writes that span EOF might trigger an IO size update on completion, + * so consider them to be dirty for the purposes of O_DSYNC even if + * there is no other metadata changes pending or have been made here. + */ + if ((flags & IOMAP_WRITE) && offset + length > i_size_read(inode)) + iomap->flags |= IOMAP_F_DIRTY; return xfs_bmbt_to_iomap(ip, iomap, &imap, shared); out_found: -- cgit v1.2.3