ocfs2: Write support for inline data

This fixes up write, truncate, mmap, and RESVSP/UNRESVP to understand inline
inode data.

For the most part, the changes to the core write code can be relied on to do
the heavy lifting. Any code calling ocfs2_write_begin (including shared
writeable mmap) can count on it doing the right thing with respect to
growing inline data to an extent tree.

Size reducing truncates, including UNRESVP can simply zero that portion of
the inode block being removed. Size increasing truncatesm, including RESVP
have to be a little bit smarter and grow the inode to an extent tree if
necessary.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Reviewed-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/ocfs2/journal.h b/fs/ocfs2/journal.h
index ce60aab013aa..4b32e0961568 100644
--- a/fs/ocfs2/journal.h
+++ b/fs/ocfs2/journal.h
@@ -282,6 +282,9 @@ int                  ocfs2_journal_dirty_data(handle_t *handle,
  * prev. group desc. if we relink. */
 #define OCFS2_SUBALLOC_ALLOC (3)
 
+#define OCFS2_INLINE_TO_EXTENTS_CREDITS (OCFS2_SUBALLOC_ALLOC           \
+                                         + OCFS2_INODE_UPDATE_CREDITS)
+
 /* dinode + group descriptor update. We don't relink on free yet. */
 #define OCFS2_SUBALLOC_FREE  (2)