ext4: add ext4_get_block_dax()

DAX wants different semantics from any currently-existing ext4 get_block
callback.  Unlike ext4_get_block_write(), it needs to honour the
'create' flag, and unlike ext4_get_block(), it needs to be able to
return unwritten extents.  So introduce a new ext4_get_block_dax() which
has those semantics.

We could also change ext4_get_block_write() to honour the 'create' flag,
but that might have consequences on other users that I do not currently
understand.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 32071f5..fd1f28b 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2272,6 +2272,8 @@ struct buffer_head *ext4_getblk(handle_t *, struct inode *, ext4_lblk_t, int);
 struct buffer_head *ext4_bread(handle_t *, struct inode *, ext4_lblk_t, int);
 int ext4_get_block_write(struct inode *inode, sector_t iblock,
                         struct buffer_head *bh_result, int create);
+int ext4_get_block_dax(struct inode *inode, sector_t iblock,
+                        struct buffer_head *bh_result, int create);
 int ext4_get_block(struct inode *inode, sector_t iblock,
                                struct buffer_head *bh_result, int create);
 int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,

diff --cc fs/ext4/file.c
Simple merge

diff --cc fs/ext4/inode.c
Simple merge