ext4: Fix sparse warning: Using plain integer as NULL pointer

This patch fixes the warning "Using plain integer as NULL pointer",
generated by sparse, by replacing the offending 0s with NULL.
Signed-off-by: NPeter Huewe <peterhuewe@gmx.de>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/extents.c

@@ -1034,7 +1034,7 @@ static int ext4_ext_split(handle_t *handle, struct inode *inode,
 		for (i = 0; i < depth; i++) {
 			if (!ablocks[i])
 				continue;
-			ext4_free_blocks(handle, inode, 0, ablocks[i], 1,
+			ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
 					 EXT4_FREE_BLOCKS_METADATA);
 		}
 	}
@@ -2059,7 +2059,7 @@ static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
 	if (err)
 		return err;
 	ext_debug("index is empty, remove it, free block %llu\n", leaf);
-	ext4_free_blocks(handle, inode, 0, leaf, 1,
+	ext4_free_blocks(handle, inode, NULL, leaf, 1,
 			 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
 	return err;
 }
@@ -2156,7 +2156,7 @@ static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
 		num = le32_to_cpu(ex->ee_block) + ee_len - from;
 		start = ext4_ext_pblock(ex) + ee_len - num;
 		ext_debug("free last %u blocks starting %llu\n", num, start);
-		ext4_free_blocks(handle, inode, 0, start, num, flags);
+		ext4_free_blocks(handle, inode, NULL, start, num, flags);
 	} else if (from == le32_to_cpu(ex->ee_block)
 		   && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
 		printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n",
@@ -3485,7 +3485,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
 		/* not a good idea to call discard here directly,
 		 * but otherwise we'd need to call it every free() */
 		ext4_discard_preallocations(inode);
-		ext4_free_blocks(handle, inode, 0, ext4_ext_pblock(&newex),
+		ext4_free_blocks(handle, inode, NULL, ext4_ext_pblock(&newex),
 				 ext4_ext_get_actual_len(&newex), 0);
 		goto out2;
 	}

fs/ext4/ialloc.c

@@ -649,7 +649,7 @@ static int find_group_other(struct super_block *sb, struct inode *parent,
 		*group = parent_group + flex_size;
 		if (*group > ngroups)
 			*group = 0;
-		return find_group_orlov(sb, parent, group, mode, 0);
+		return find_group_orlov(sb, parent, group, mode, NULL);
 	}
 
 	/*

fs/ext4/inode.c

@@ -720,7 +720,7 @@ static int ext4_alloc_blocks(handle_t *handle, struct inode *inode,
 	return ret;
 failed_out:
 	for (i = 0; i < index; i++)
-		ext4_free_blocks(handle, inode, 0, new_blocks[i], 1, 0);
+		ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0);
 	return ret;
 }
 
@@ -823,20 +823,20 @@ static int ext4_alloc_branch(handle_t *handle, struct inode *inode,
 	return err;
 failed:
 	/* Allocation failed, free what we already allocated */
-	ext4_free_blocks(handle, inode, 0, new_blocks[0], 1, 0);
+	ext4_free_blocks(handle, inode, NULL, new_blocks[0], 1, 0);
 	for (i = 1; i <= n ; i++) {
 		/*
 		 * branch[i].bh is newly allocated, so there is no
 		 * need to revoke the block, which is why we don't
 		 * need to set EXT4_FREE_BLOCKS_METADATA.
 		 */
-		ext4_free_blocks(handle, inode, 0, new_blocks[i], 1,
+		ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1,
 				 EXT4_FREE_BLOCKS_FORGET);
 	}
 	for (i = n+1; i < indirect_blks; i++)
-		ext4_free_blocks(handle, inode, 0, new_blocks[i], 1, 0);
+		ext4_free_blocks(handle, inode, NULL, new_blocks[i], 1, 0);
 
-	ext4_free_blocks(handle, inode, 0, new_blocks[i], num, 0);
+	ext4_free_blocks(handle, inode, NULL, new_blocks[i], num, 0);
 
 	return err;
 }
@@ -924,7 +924,7 @@ static int ext4_splice_branch(handle_t *handle, struct inode *inode,
 		ext4_free_blocks(handle, inode, where[i].bh, 0, 1,
 				 EXT4_FREE_BLOCKS_FORGET);
 	}
-	ext4_free_blocks(handle, inode, 0, le32_to_cpu(where[num].key),
+	ext4_free_blocks(handle, inode, NULL, le32_to_cpu(where[num].key),
 			 blks, 0);
 
 	return err;
@@ -4228,7 +4228,7 @@ static int ext4_clear_blocks(handle_t *handle, struct inode *inode,
 	for (p = first; p < last; p++)
 		*p = 0;
 
-	ext4_free_blocks(handle, inode, 0, block_to_free, count, flags);
+	ext4_free_blocks(handle, inode, NULL, block_to_free, count, flags);
 	return 0;
 }
 
@@ -4416,7 +4416,7 @@ static void ext4_free_branches(handle_t *handle, struct inode *inode,
 			 * transaction where the data blocks are
 			 * actually freed.
 			 */
-			ext4_free_blocks(handle, inode, 0, nr, 1,
+			ext4_free_blocks(handle, inode, NULL, nr, 1,
 					 EXT4_FREE_BLOCKS_METADATA|
 					 EXT4_FREE_BLOCKS_FORGET);
 
@@ -4875,7 +4875,7 @@ struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
 		return inode;
 
 	ei = EXT4_I(inode);
-	iloc.bh = 0;
+	iloc.bh = NULL;
 
 	ret = __ext4_get_inode_loc(inode, &iloc, 0);
 	if (ret < 0)

fs/ext4/migrate.c

@@ -263,7 +263,7 @@ static int free_dind_blocks(handle_t *handle,
 	for (i = 0; i < max_entries; i++) {
 		if (tmp_idata[i]) {
 			extend_credit_for_blkdel(handle, inode);
-			ext4_free_blocks(handle, inode, 0,
+			ext4_free_blocks(handle, inode, NULL,
 					 le32_to_cpu(tmp_idata[i]), 1,
 					 EXT4_FREE_BLOCKS_METADATA |
 					 EXT4_FREE_BLOCKS_FORGET);
@@ -271,7 +271,7 @@ static int free_dind_blocks(handle_t *handle,
 	}
 	put_bh(bh);
 	extend_credit_for_blkdel(handle, inode);
-	ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
+	ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
 			 EXT4_FREE_BLOCKS_METADATA |
 			 EXT4_FREE_BLOCKS_FORGET);
 	return 0;
@@ -302,7 +302,7 @@ static int free_tind_blocks(handle_t *handle,
 	}
 	put_bh(bh);
 	extend_credit_for_blkdel(handle, inode);
-	ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
+	ext4_free_blocks(handle, inode, NULL, le32_to_cpu(i_data), 1,
 			 EXT4_FREE_BLOCKS_METADATA |
 			 EXT4_FREE_BLOCKS_FORGET);
 	return 0;
@@ -315,7 +315,7 @@ static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data)
 	/* ei->i_data[EXT4_IND_BLOCK] */
 	if (i_data[0]) {
 		extend_credit_for_blkdel(handle, inode);
-		ext4_free_blocks(handle, inode, 0,
+		ext4_free_blocks(handle, inode, NULL,
 				le32_to_cpu(i_data[0]), 1,
 				 EXT4_FREE_BLOCKS_METADATA |
 				 EXT4_FREE_BLOCKS_FORGET);
@@ -428,7 +428,7 @@ static int free_ext_idx(handle_t *handle, struct inode *inode,
 	}
 	put_bh(bh);
 	extend_credit_for_blkdel(handle, inode);
-	ext4_free_blocks(handle, inode, 0, block, 1,
+	ext4_free_blocks(handle, inode, NULL, block, 1,
 			 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
 	return retval;
 }

fs/ext4/page-io.c

@@ -279,9 +279,9 @@ void ext4_io_submit(struct ext4_io_submit *io)
 		BUG_ON(bio_flagged(io->io_bio, BIO_EOPNOTSUPP));
 		bio_put(io->io_bio);
 	}
-	io->io_bio = 0;
+	io->io_bio = NULL;
 	io->io_op = 0;
-	io->io_end = 0;
+	io->io_end = NULL;
 }
 
 static int io_submit_init(struct ext4_io_submit *io,

fs/ext4/super.c

@@ -1451,7 +1451,7 @@ static int parse_options(char *options, struct super_block *sb,
 		 * Initialize args struct so we know whether arg was
 		 * found; some options take optional arguments.
 		 */
-		args[0].to = args[0].from = 0;
+		args[0].to = args[0].from = NULL;
 		token = match_token(p, tokens, args);
 		switch (token) {
 		case Opt_bsd_df:

fs/ext4/xattr.c

@@ -833,7 +833,7 @@ ext4_xattr_block_set(handle_t *handle, struct inode *inode,
 			new_bh = sb_getblk(sb, block);
 			if (!new_bh) {
 getblk_failed:
-				ext4_free_blocks(handle, inode, 0, block, 1,
+				ext4_free_blocks(handle, inode, NULL, block, 1,
 						 EXT4_FREE_BLOCKS_METADATA);
 				error = -EIO;
 				goto cleanup;