Merge branch 'iomap-4.19-merge' into linux-gfs2/for-next

Merge xfs branch 'iomap-4.19-merge' into linux-gfs2/for-next.  This
brings in readpage and direct I/O support for inline data.

The IOMAP_F_BUFFER_HEAD flag introduced in commit "iomap: add initial
support for writes without buffer heads" needs to be set for gfs2 as
well, so do that in the merge.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

fs/gfs2/bmap.c

@@ -890,7 +890,7 @@ static int gfs2_iomap_get(struct inode *inode, loff_t pos, loff_t length,
 	iomap->addr = be64_to_cpu(*ptr) << inode->i_blkbits;
 	iomap->length = len << inode->i_blkbits;
 	iomap->type = IOMAP_MAPPED;
-	iomap->flags = IOMAP_F_MERGED;
+	iomap->flags |= IOMAP_F_MERGED;
 	if (eob)
 		iomap->flags |= IOMAP_F_GFS2_BOUNDARY;
 
@@ -1084,6 +1084,8 @@ static int gfs2_iomap_begin(struct inode *inode, loff_t pos, loff_t length,
 	struct metapath mp = { .mp_aheight = 1, };
 	int ret;
 
+	iomap->flags |= IOMAP_F_BUFFER_HEAD;
+
 	trace_gfs2_iomap_start(ip, pos, length, flags);
 	if ((flags & IOMAP_WRITE) && !(flags & IOMAP_DIRECT)) {
 		ret = gfs2_iomap_begin_write(inode, pos, length, flags, iomap);

fs/xfs/xfs_iomap.c

@@ -626,7 +626,7 @@ xfs_file_iomap_begin_delay(
 	 * Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch
 	 * them out if the write happens to fail.
 	 */
-	iomap->flags = IOMAP_F_NEW;
+	iomap->flags |= IOMAP_F_NEW;
 	trace_xfs_iomap_alloc(ip, offset, count, 0, &got);
 done:
 	if (isnullstartblock(got.br_startblock))
@@ -1019,6 +1019,8 @@ xfs_file_iomap_begin(
 	if (XFS_FORCED_SHUTDOWN(mp))
 		return -EIO;
 
+	iomap->flags |= IOMAP_F_BUFFER_HEAD;
+
 	if (((flags & (IOMAP_WRITE | IOMAP_DIRECT)) == IOMAP_WRITE) &&
 			!IS_DAX(inode) && !xfs_get_extsz_hint(ip)) {
 		/* Reserve delalloc blocks for regular writeback. */
@@ -1119,7 +1121,7 @@ xfs_file_iomap_begin(
 	if (error)
 		return error;
 
-	iomap->flags = IOMAP_F_NEW;
+	iomap->flags |= IOMAP_F_NEW;
 	trace_xfs_iomap_alloc(ip, offset, length, 0, &imap);
 
 out_finish:

include/linux/iomap.h

@@ -30,6 +30,7 @@ struct vm_fault;
  */
 #define IOMAP_F_NEW		0x01	/* blocks have been newly allocated */
 #define IOMAP_F_DIRTY		0x02	/* uncommitted metadata */
+#define IOMAP_F_BUFFER_HEAD	0x04	/* file system requires buffer heads */
 
 /*
  * Flags that only need to be reported for IOMAP_REPORT requests:
@@ -99,6 +100,10 @@ struct iomap_ops {
 
 ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from,
 		const struct iomap_ops *ops);
+int iomap_readpage(struct page *page, const struct iomap_ops *ops);
+int iomap_readpages(struct address_space *mapping, struct list_head *pages,
+		unsigned nr_pages, const struct iomap_ops *ops);
+int iomap_set_page_dirty(struct page *page);
 int iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len,
 		const struct iomap_ops *ops);
 int iomap_zero_range(struct inode *inode, loff_t pos, loff_t len,