dquot: cleanup space allocation / freeing routines

Get rid of the alloc_space, free_space, reserve_space, claim_space and
release_rsv dquot operations - they are always called from the filesystem
and if a filesystem really needs their own (which none currently does)
it can just call into it's own routine directly.

Move shared logic into the common __dquot_alloc_space,
dquot_claim_space_nodirty and __dquot_free_space low-level methods,
and rationalize the wrappers around it to move as much as possible
code into the common block for CONFIG_QUOTA vs not.  Also rename
all these helpers to be named dquot_* instead of vfs_dq_*.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/reiserfs/bitmap.c b/fs/reiserfs/bitmap.c
index 65c8727..dc014f7 100644
--- a/fs/reiserfs/bitmap.c
+++ b/fs/reiserfs/bitmap.c
@@ -425,7 +425,7 @@
 
 	journal_mark_dirty(th, s, sbh);
 	if (for_unformatted)
-		vfs_dq_free_block_nodirty(inode, 1);
+		dquot_free_block_nodirty(inode, 1);
 }
 
 void reiserfs_free_block(struct reiserfs_transaction_handle *th,
@@ -1049,7 +1049,7 @@
 			       amount_needed, hint->inode->i_uid);
 #endif
 		quota_ret =
-		    vfs_dq_alloc_block_nodirty(hint->inode, amount_needed);
+		    dquot_alloc_block_nodirty(hint->inode, amount_needed);
 		if (quota_ret)	/* Quota exceeded? */
 			return QUOTA_EXCEEDED;
 		if (hint->preallocate && hint->prealloc_size) {
@@ -1058,7 +1058,7 @@
 				       "reiserquota: allocating (prealloc) %d blocks id=%u",
 				       hint->prealloc_size, hint->inode->i_uid);
 #endif
-			quota_ret = vfs_dq_prealloc_block_nodirty(hint->inode,
+			quota_ret = dquot_prealloc_block_nodirty(hint->inode,
 							 hint->prealloc_size);
 			if (quota_ret)
 				hint->preallocate = hint->prealloc_size = 0;
@@ -1092,7 +1092,7 @@
 					       hint->inode->i_uid);
 #endif
 				/* Free not allocated blocks */
-				vfs_dq_free_block_nodirty(hint->inode,
+				dquot_free_block_nodirty(hint->inode,
 					amount_needed + hint->prealloc_size -
 					nr_allocated);
 			}
@@ -1125,7 +1125,7 @@
 			       REISERFS_I(hint->inode)->i_prealloc_count,
 			       hint->inode->i_uid);
 #endif
-		vfs_dq_free_block_nodirty(hint->inode, amount_needed +
+		dquot_free_block_nodirty(hint->inode, amount_needed +
 					 hint->prealloc_size - nr_allocated -
 					 REISERFS_I(hint->inode)->
 					 i_prealloc_count);