fs: pass exact type of data dirties to ->dirty_inode

Tell the filesystem if we just updated timestamp (I_DIRTY_SYNC) or
anything else, so that the filesystem can track internally if it
needs to push out a transaction for fdatasync or not.

This is just the prototype change with no user for it yet.  I plan
to push large XFS changes for the next merge window, and getting
this trivial infrastructure in this window would help a lot to avoid
tree interdependencies.

Also remove incorrect comments that ->dirty_inode can't block.  That
has been changed a long time ago, and many implementations rely on it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 2 insertions, 2 deletions

diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 61b31acb9176..57d827d6071d 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -104,7 +104,7 @@ of the locking scheme for directory operations.
 prototypes:
         struct inode *(*alloc_inode)(struct super_block *sb);
         void (*destroy_inode)(struct inode *);
-        void (*dirty_inode) (struct inode *);
+        void (*dirty_inode) (struct inode *, int flags);
         int (*write_inode) (struct inode *, struct writeback_control *wbc);
         int (*drop_inode) (struct inode *);
         void (*evict_inode) (struct inode *);
@@ -126,7 +126,7 @@ locking rules:
                         s_umount
 alloc_inode:
 destroy_inode:
-dirty_inode:                            (must not sleep)
+dirty_inode:
 write_inode:
 drop_inode:                             !!!inode->i_lock!!!
 evict_inode: