Merge tag 'xfs-4.14-fixes-6' of git://git.kernel.org/pub/scm/fs/xfs/x…

…fs-linux

Pull xfs fixes from Darrick Wong:

 - fix some more CONFIG_XFS_RT related build problems

 - fix data loss when writeback at eof races eofblocks gc and loses

 - invalidate page cache after fs finishes a dio write

 - remove dirty page state when invalidating pages so releasepage does
   the right thing when handed a dirty page

* tag 'xfs-4.14-fixes-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: move two more RT specific functions into CONFIG_XFS_RT
  xfs: trim writepage mapping to within eof
  fs: invalidate page cache after end_io() in dio completion
  xfs: cancel dirty pages on invalidation

fs/direct-io.c

@@ -265,12 +265,24 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, unsigned int flags)
 	if (ret == 0)
 		ret = transferred;
 
+	if (dio->end_io) {
+		// XXX: ki_pos??
+		err = dio->end_io(dio->iocb, offset, ret, dio->private);
+		if (err)
+			ret = err;
+	}
+
 	/*
 	 * Try again to invalidate clean pages which might have been cached by
 	 * non-direct readahead, or faulted in by get_user_pages() if the source
 	 * of the write was an mmap'ed region of the file we're writing.  Either
 	 * one is a pretty crazy thing to do, so we don't support it 100%.  If
 	 * this invalidation fails, tough, the write still worked...
+	 *
+	 * And this page cache invalidation has to be after dio->end_io(), as
+	 * some filesystems convert unwritten extents to real allocations in
+	 * end_io() when necessary, otherwise a racing buffer read would cache
+	 * zeros from unwritten extents.
 	 */
 	if (flags & DIO_COMPLETE_INVALIDATE &&
 	    ret > 0 && dio->op == REQ_OP_WRITE &&
@@ -281,14 +293,6 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, unsigned int flags)
 		WARN_ON_ONCE(err);
 	}
 
-	if (dio->end_io) {
-
-		// XXX: ki_pos??
-		err = dio->end_io(dio->iocb, offset, ret, dio->private);
-		if (err)
-			ret = err;
-	}
-
 	if (!(dio->flags & DIO_SKIP_DIO_COUNT))
 		inode_dio_end(dio->inode);
 

fs/iomap.c

@@ -714,23 +714,9 @@ static ssize_t iomap_dio_complete(struct iomap_dio *dio)
 {
 	struct kiocb *iocb = dio->iocb;
 	struct inode *inode = file_inode(iocb->ki_filp);
+	loff_t offset = iocb->ki_pos;
 	ssize_t ret;
 
-	/*
-	 * Try again to invalidate clean pages which might have been cached by
-	 * non-direct readahead, or faulted in by get_user_pages() if the source
-	 * of the write was an mmap'ed region of the file we're writing.  Either
-	 * one is a pretty crazy thing to do, so we don't support it 100%.  If
-	 * this invalidation fails, tough, the write still worked...
-	 */
-	if (!dio->error &&
-	    (dio->flags & IOMAP_DIO_WRITE) && inode->i_mapping->nrpages) {
-		ret = invalidate_inode_pages2_range(inode->i_mapping,
-				iocb->ki_pos >> PAGE_SHIFT,
-				(iocb->ki_pos + dio->size - 1) >> PAGE_SHIFT);
-		WARN_ON_ONCE(ret);
-	}
-
 	if (dio->end_io) {
 		ret = dio->end_io(iocb,
 				dio->error ? dio->error : dio->size,
@@ -742,12 +728,33 @@ static ssize_t iomap_dio_complete(struct iomap_dio *dio)
 	if (likely(!ret)) {
 		ret = dio->size;
 		/* check for short read */
-		if (iocb->ki_pos + ret > dio->i_size &&
+		if (offset + ret > dio->i_size &&
 		    !(dio->flags & IOMAP_DIO_WRITE))
-			ret = dio->i_size - iocb->ki_pos;
+			ret = dio->i_size - offset;
 		iocb->ki_pos += ret;
 	}
 
+	/*
+	 * Try again to invalidate clean pages which might have been cached by
+	 * non-direct readahead, or faulted in by get_user_pages() if the source
+	 * of the write was an mmap'ed region of the file we're writing.  Either
+	 * one is a pretty crazy thing to do, so we don't support it 100%.  If
+	 * this invalidation fails, tough, the write still worked...
+	 *
+	 * And this page cache invalidation has to be after dio->end_io(), as
+	 * some filesystems convert unwritten extents to real allocations in
+	 * end_io() when necessary, otherwise a racing buffer read would cache
+	 * zeros from unwritten extents.
+	 */
+	if (!dio->error &&
+	    (dio->flags & IOMAP_DIO_WRITE) && inode->i_mapping->nrpages) {
+		int err;
+		err = invalidate_inode_pages2_range(inode->i_mapping,
+				offset >> PAGE_SHIFT,
+				(offset + dio->size - 1) >> PAGE_SHIFT);
+		WARN_ON_ONCE(err);
+	}
+
 	inode_dio_end(file_inode(iocb->ki_filp));
 	kfree(dio);
 

fs/xfs/libxfs/xfs_bmap.c

@@ -3852,6 +3852,17 @@ xfs_trim_extent(
 	}
 }
 
+/* trim extent to within eof */
+void
+xfs_trim_extent_eof(
+	struct xfs_bmbt_irec	*irec,
+	struct xfs_inode	*ip)
+
+{
+	xfs_trim_extent(irec, 0, XFS_B_TO_FSB(ip->i_mount,
+					      i_size_read(VFS_I(ip))));
+}
+
 /*
  * Trim the returned map to the required bounds
  */

fs/xfs/libxfs/xfs_bmap.h

@@ -208,6 +208,7 @@ void	xfs_bmap_trace_exlist(struct xfs_inode *ip, xfs_extnum_t cnt,
 
 void	xfs_trim_extent(struct xfs_bmbt_irec *irec, xfs_fileoff_t bno,
 		xfs_filblks_t len);
+void	xfs_trim_extent_eof(struct xfs_bmbt_irec *, struct xfs_inode *);
 int	xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
 void	xfs_bmap_local_to_extents_empty(struct xfs_inode *ip, int whichfork);
 void	xfs_bmap_add_free(struct xfs_mount *mp, struct xfs_defer_ops *dfops,

fs/xfs/xfs_aops.c

@@ -446,6 +446,19 @@ xfs_imap_valid(
 {
 	offset >>= inode->i_blkbits;
 
+	/*
+	 * We have to make sure the cached mapping is within EOF to protect
+	 * against eofblocks trimming on file release leaving us with a stale
+	 * mapping. Otherwise, a page for a subsequent file extending buffered
+	 * write could get picked up by this writeback cycle and written to the
+	 * wrong blocks.
+	 *
+	 * Note that what we really want here is a generic mapping invalidation
+	 * mechanism to protect us from arbitrary extent modifying contexts, not
+	 * just eofblocks.
+	 */
+	xfs_trim_extent_eof(imap, XFS_I(inode));
+
 	return offset >= imap->br_startoff &&
 		offset < imap->br_startoff + imap->br_blockcount;
 }
@@ -735,6 +748,14 @@ xfs_vm_invalidatepage(
 {
 	trace_xfs_invalidatepage(page->mapping->host, page, offset,
 				 length);
+
+	/*
+	 * If we are invalidating the entire page, clear the dirty state from it
+	 * so that we can check for attempts to release dirty cached pages in
+	 * xfs_vm_releasepage().
+	 */
+	if (offset == 0 && length >= PAGE_SIZE)
+		cancel_dirty_page(page);
 	block_invalidatepage(page, offset, length);
 }
 
@@ -1190,25 +1211,27 @@ xfs_vm_releasepage(
 	 * mm accommodates an old ext3 case where clean pages might not have had
 	 * the dirty bit cleared. Thus, it can send actual dirty pages to
 	 * ->releasepage() via shrink_active_list(). Conversely,
-	 * block_invalidatepage() can send pages that are still marked dirty
-	 * but otherwise have invalidated buffers.
+	 * block_invalidatepage() can send pages that are still marked dirty but
+	 * otherwise have invalidated buffers.
 	 *
 	 * We want to release the latter to avoid unnecessary buildup of the
-	 * LRU, skip the former and warn if we've left any lingering
-	 * delalloc/unwritten buffers on clean pages. Skip pages with delalloc
-	 * or unwritten buffers and warn if the page is not dirty. Otherwise
-	 * try to release the buffers.
+	 * LRU, so xfs_vm_invalidatepage() clears the page dirty flag on pages
+	 * that are entirely invalidated and need to be released.  Hence the
+	 * only time we should get dirty pages here is through
+	 * shrink_active_list() and so we can simply skip those now.
+	 *
+	 * warn if we've left any lingering delalloc/unwritten buffers on clean
+	 * or invalidated pages we are about to release.
 	 */
+	if (PageDirty(page))
+		return 0;
+
 	xfs_count_page_state(page, &delalloc, &unwritten);
 
-	if (delalloc) {
-		WARN_ON_ONCE(!PageDirty(page));
+	if (WARN_ON_ONCE(delalloc))
 		return 0;
-	}
-	if (unwritten) {
-		WARN_ON_ONCE(!PageDirty(page));
+	if (WARN_ON_ONCE(unwritten))
 		return 0;
-	}
 
 	return try_to_free_buffers(page);
 }

fs/xfs/xfs_fsmap.c

@@ -367,29 +367,6 @@ xfs_getfsmap_datadev_helper(
 	return xfs_getfsmap_helper(cur->bc_tp, info, rec, rec_daddr);
 }
 
-/* Transform a rtbitmap "record" into a fsmap */
-STATIC int
-xfs_getfsmap_rtdev_rtbitmap_helper(
-	struct xfs_trans		*tp,
-	struct xfs_rtalloc_rec		*rec,
-	void				*priv)
-{
-	struct xfs_mount		*mp = tp->t_mountp;
-	struct xfs_getfsmap_info	*info = priv;
-	struct xfs_rmap_irec		irec;
-	xfs_daddr_t			rec_daddr;
-
-	rec_daddr = XFS_FSB_TO_BB(mp, rec->ar_startblock);
-
-	irec.rm_startblock = rec->ar_startblock;
-	irec.rm_blockcount = rec->ar_blockcount;
-	irec.rm_owner = XFS_RMAP_OWN_NULL;	/* "free" */
-	irec.rm_offset = 0;
-	irec.rm_flags = 0;
-
-	return xfs_getfsmap_helper(tp, info, &irec, rec_daddr);
-}
-
 /* Transform a bnobt irec into a fsmap */
 STATIC int
 xfs_getfsmap_datadev_bnobt_helper(
@@ -475,6 +452,30 @@ xfs_getfsmap_logdev(
 	return xfs_getfsmap_helper(tp, info, &rmap, 0);
 }
 
+#ifdef CONFIG_XFS_RT
+/* Transform a rtbitmap "record" into a fsmap */
+STATIC int
+xfs_getfsmap_rtdev_rtbitmap_helper(
+	struct xfs_trans		*tp,
+	struct xfs_rtalloc_rec		*rec,
+	void				*priv)
+{
+	struct xfs_mount		*mp = tp->t_mountp;
+	struct xfs_getfsmap_info	*info = priv;
+	struct xfs_rmap_irec		irec;
+	xfs_daddr_t			rec_daddr;
+
+	rec_daddr = XFS_FSB_TO_BB(mp, rec->ar_startblock);
+
+	irec.rm_startblock = rec->ar_startblock;
+	irec.rm_blockcount = rec->ar_blockcount;
+	irec.rm_owner = XFS_RMAP_OWN_NULL;	/* "free" */
+	irec.rm_offset = 0;
+	irec.rm_flags = 0;
+
+	return xfs_getfsmap_helper(tp, info, &irec, rec_daddr);
+}
+
 /* Execute a getfsmap query against the realtime device. */
 STATIC int
 __xfs_getfsmap_rtdev(
@@ -521,7 +522,6 @@ __xfs_getfsmap_rtdev(
 	return query_fn(tp, info);
 }
 
-#ifdef CONFIG_XFS_RT
 /* Actually query the realtime bitmap. */
 STATIC int
 xfs_getfsmap_rtdev_rtbitmap_query(