reiserfsprogs: Fix sparse "warning: Using plain integer as NULL pointer"

Signed-off-by: Jeff Mahoney <jeffm@suse.com>

27 files changed, 192 insertions, 188 deletions

diff --git a/debugreiserfs/corruption.c b/debugreiserfs/corruption.c
index 58a586b..d8790e5 100644
--- a/debugreiserfs/corruption.c
+++ b/debugreiserfs/corruption.c
@@ -99,7 +99,7 @@ static void edit_super_block(reiserfs_filsys_t *fs)
 	size_t n;
 	int num;
 
-	str = 0;
+	str = NULL;
 	n = 0;
 
 	/* bs_block_count */
@@ -239,7 +239,7 @@ static void corrupt_clobber_hash(char *name, struct item_head *ih,
 void do_corrupt_one_block(reiserfs_filsys_t *fs, char *fline)
 {
 	struct buffer_head *bh;
-	char *line = 0;
+	char *line = NULL;
 	size_t n = 0;
 	unsigned long block;
 
@@ -319,7 +319,7 @@ void do_corrupt_one_block(reiserfs_filsys_t *fs, char *fline)
 		while (getline(&line, &n, stdin) != -1) {
 			if (line[0] == '\n') {
 				free(line);
-				line = 0;
+				line = NULL;
 				n = 0;
 				break;
 			}
@@ -330,7 +330,7 @@ void do_corrupt_one_block(reiserfs_filsys_t *fs, char *fline)
 			}
 
 			free(line);
-			line = 0;
+			line = NULL;
 			n = 0;
 		}
 	}
@@ -772,7 +772,7 @@ void do_leaves_corruption(reiserfs_filsys_t *fs, unsigned long nr_leaves_cr)
 	unsigned long nr_leaves = 0;
 	unsigned int i, should_be_corrupted;
 
-	srand(time(0));
+	srand(time(NULL));
 	printf("%lu leaves will be corrupted\n", nr_leaves_cr);
 	if ((data(fs)->log_file_name) && (data(fs)->log)) {
 		fprintf(data(fs)->log,
@@ -898,7 +898,7 @@ void do_ih_random_corrupt(reiserfs_filsys_t *fs, unsigned long nr_leaves_cr)
 	unsigned long nr_leaves = 0;
 	unsigned int should_be_corrupted = 0;
 
-	srand(time(0));
+	srand(time(NULL));
 
 	printf("item headers in %lu leaves will be corrupted\n", nr_leaves_cr);
 	if ((data(fs)->log_file_name) && (data(fs)->log)) {
@@ -1010,7 +1010,7 @@ void do_dir_random_corrupt(reiserfs_filsys_t *fs, unsigned long nr_leaves_cr)
 	unsigned long nr_leaves = 0;
 	unsigned int should_be_corrupted = 0;
 
-	srand(time(0));
+	srand(time(NULL));
 
 	printf("DIR items in %lu leaves will be corrupted\n", nr_leaves_cr);
 	if ((data(fs)->log_file_name) && (data(fs)->log)) {
@@ -1095,7 +1095,7 @@ void do_sd_random_corrupt(reiserfs_filsys_t *fs, unsigned long nr_leaves_cr)
 	unsigned long nr_leaves = 0;
 	unsigned int should_be_corrupted = 0;
 
-	srand(time(0));
+	srand(time(NULL));
 
 	printf("SD items in %lu leaves will be corrupted\n", nr_leaves_cr);
 	if ((data(fs)->log_file_name) && (data(fs)->log)) {
@@ -1180,7 +1180,7 @@ void do_ind_random_corrupt(reiserfs_filsys_t *fs, unsigned long nr_leaves_cr)
 	unsigned long nr_leaves = 0;
 	unsigned int should_be_corrupted = 0;
 
-	srand(time(0));
+	srand(time(NULL));
 
 	printf("IND items in %lu leaves will be corrupted\n", nr_leaves_cr);
 	if ((data(fs)->log_file_name) && (data(fs)->log)) {
@@ -1336,7 +1336,7 @@ void what_to_corrupt(reiserfs_filsys_t *fs, char *corruption_command)
 
 void do_fs_random_corrupt(reiserfs_filsys_t *fs)
 {
-	char *line = 0;
+	char *line = NULL;
 	size_t n = 0;
 
 	printf("Corrupting fs. Please insert one of the following command\n"
@@ -1352,7 +1352,7 @@ void do_fs_random_corrupt(reiserfs_filsys_t *fs)
 	while (getline(&line, &n, stdin) != -1) {
 		if (line[0] == '\n') {
 			free(line);
-			line = 0;
+			line = NULL;
 			n = 0;
 			break;
 		}
@@ -1365,7 +1365,7 @@ void do_fs_random_corrupt(reiserfs_filsys_t *fs)
 		what_to_corrupt(fs, line);
 
 		free(line);
-		line = 0;
+		line = NULL;
 		n = 0;
 	}
 }
diff --git a/fsck/check_tree.c b/fsck/check_tree.c
index 3304f79..8135d79 100644
--- a/fsck/check_tree.c
+++ b/fsck/check_tree.c
@@ -1030,7 +1030,7 @@ static struct reiserfs_key *lkey(struct buffer_head **path, int h)
 			return internal_key(path[h - 1], pos - 1);
 		h--;
 	}
-	return 0;
+	return NULL;
 }
 
 /* path[h] - leaf node */
@@ -1044,7 +1044,7 @@ static struct reiserfs_key *rkey(struct buffer_head **path, int h)
 			return internal_key(path[h - 1], pos);
 		h--;
 	}
-	return 0;
+	return NULL;
 }
 
 /* are all delimiting keys correct */
diff --git a/fsck/lost+found.c b/fsck/lost+found.c
index 830faa4..56efadb 100644
--- a/fsck/lost+found.c
+++ b/fsck/lost+found.c
@@ -213,7 +213,7 @@ static __u64 _look_for_lost(reiserfs_filsys_t *fs, int link_lost_dirs)
 					rebuild_semantic_pass(&obj_key,
 							      &lost_found_dir_key,
 							      /*dot_dot */ 0,
-							      /*reloc_ih */ 0);
+							      /*reloc_ih */ NULL);
 					erase_name(strlen(lost_name));
 					/*fsck_progress ("finished\n"); */
 
@@ -233,7 +233,7 @@ static __u64 _look_for_lost(reiserfs_filsys_t *fs, int link_lost_dirs)
 					rebuild_check_regular_file(&path,
 								   tp_item_body
 								   (&path),
-								   0
+								   NULL
 								   /*reloc_ih */
 								   );
 					pathrelse(&path);
@@ -355,7 +355,7 @@ void after_lost_found(reiserfs_filsys_t *fs)
 	save_lost_found_result(fs);
 
 	id_map_free(proper_id_map(fs));
-	proper_id_map(fs) = 0;
+	proper_id_map(fs) = NULL;
 
 	fs->fs_dirt = 1;
 	reiserfs_close(fs);
diff --git a/fsck/main.c b/fsck/main.c
index ea2152f..092babe 100644
--- a/fsck/main.c
+++ b/fsck/main.c
@@ -100,39 +100,39 @@ static char *parse_options(struct fsck_data *data, int argc, char *argv[])
 			{"clean-attributes", no_argument, &mode,
 			 FSCK_CLEAN_ATTRIBUTES},
 			/* options */
-			{"logfile", required_argument, 0, 'l'},
-			{"badblocks", required_argument, 0, 'B'},
-			{"interactive", no_argument, 0, 'i'},
-			{"adjust-size", no_argument, 0, 'z'},
-			{"quiet", no_argument, 0, 'q'},
-			{"yes", no_argument, 0, 'y'},
-			{"force", no_argument, 0, 'f'},
-			{"nolog", no_argument, 0, 'n'},
+			{"logfile", required_argument, NULL, 'l'},
+			{"badblocks", required_argument, NULL, 'B'},
+			{"interactive", no_argument, NULL, 'i'},
+			{"adjust-size", no_argument, NULL, 'z'},
+			{"quiet", no_argument, NULL, 'q'},
+			{"yes", no_argument, NULL, 'y'},
+			{"force", no_argument, NULL, 'f'},
+			{"nolog", no_argument, NULL, 'n'},
 
 			/* if file exists ad reiserfs can be load of it - only
 			   blocks marked used in that bitmap will be read */
-			{"scan-marked-in-bitmap", required_argument, 0, 'b'},
+			{"scan-marked-in-bitmap", required_argument, NULL, 'b'},
 
-			{"create-passes-dump", required_argument, 0, 'd'},
+			{"create-passes-dump", required_argument, NULL, 'd'},
 
 			/* all blocks will be read */
-			{"scan-whole-partition", no_argument, 0, 'S'},
+			{"scan-whole-partition", no_argument, NULL, 'S'},
 			/* useful for -S */
-			{"hash", required_argument, 0, 'h'},
+			{"hash", required_argument, NULL, 'h'},
 
 			/* preparing rollback data */
-			{"rollback-data", required_argument, 0, 'R'},
+			{"rollback-data", required_argument, NULL, 'R'},
 
-			{"journal", required_argument, 0, 'j'},
+			{"journal", required_argument, NULL, 'j'},
 			{"no-journal-available", no_argument, &flag,
 			 OPT_SKIP_JOURNAL},
 
-			{"bad-block-file", required_argument, 0, 'B'},
+			{"bad-block-file", required_argument, NULL, 'B'},
 
 			/* start reiserfsck in background and exit */
-			{"background", no_argument, 0, 'g'},
+			{"background", no_argument, NULL, 'g'},
 
-			{0, 0, 0, 0}
+			{}
 		};
 		int option_index;
 
@@ -209,7 +209,7 @@ static char *parse_options(struct fsck_data *data, int argc, char *argv[])
 
 		case 'h':	/* --hash: suppose that this hash was used on a filesystem */
 			asprintf(&data->rebuild.defined_hash, "%s", optarg);
-			if (name2func(data->rebuild.defined_hash) == 0)
+			if (name2func(data->rebuild.defined_hash) == NULL)
 				reiserfs_panic
 				    ("reiserfsck: Unknown hash is specified: %s",
 				     data->rebuild.defined_hash);
@@ -630,7 +630,7 @@ static void reset_super_block(reiserfs_filsys_t *fs)
 static int where_to_start_from(reiserfs_filsys_t *fs)
 {
 	int ret;
-	FILE *fp = 0;
+	FILE *fp = NULL;
 	int last_run_state;
 
 	last_run_state = get_sb_fs_state(fs->fs_ondisk_sb);
@@ -640,7 +640,7 @@ static int where_to_start_from(reiserfs_filsys_t *fs)
 	/* We are able to perform the next step only if there is a file with the previous
 	 * step results. */
 	fp = open_file(state_dump_file(fs), "r");
-	if (fp == 0) {
+	if (fp == NULL) {
 		set_sb_fs_state(fs->fs_ondisk_sb, 0);
 		return START_FROM_THE_BEGINNING;
 	}
@@ -1300,7 +1300,7 @@ static void fsck_rollback(reiserfs_filsys_t *fs)
 
 	close(fs->fs_journal_dev);
 	free(fs->fs_file_name);
-	fs->fs_file_name = 0;
+	fs->fs_file_name = NULL;
 	close(fs->fs_dev);
 	freemem(fs);
 
diff --git a/fsck/pass0.c b/fsck/pass0.c
index 68ff8c2..cf04581 100644
--- a/fsck/pass0.c
+++ b/fsck/pass0.c
@@ -364,7 +364,7 @@ static int verify_directory_item(reiserfs_filsys_t *fs, struct buffer_head *bh,
 						     get_sb_hash_code(fs->
 								      fs_ondisk_sb));
 /*		add_hash_hit (fs, hash_code);*/
-				if (code2func(hash_code) != 0) {
+				if (code2func(hash_code) != NULL) {
 					/* deh_offset matches to some hash of the name */
 					if (fsck_hash_defined(fs) &&
 					    hash_code !=
@@ -2038,7 +2038,7 @@ static void choose_hash_function(reiserfs_filsys_t *fs)
 		return;
 
 	max = 0;
-	hash_code = func2code(0);
+	hash_code = func2code(NULL);
 
 	for (i = 0; i < fsck_data(fs)->rebuild.hash_amount; i++) {
 		/* remember hash whihc got more hits */
@@ -2294,7 +2294,7 @@ static void after_pass_0(reiserfs_filsys_t *fs)
 
 	/* free what we do not need anymore */
 	reiserfs_delete_bitmap(fsck_source_bitmap(fs));
-	fsck_source_bitmap(fs) = 0;
+	fsck_source_bitmap(fs) = NULL;
 
 	if (!fsck_run_one_step(fs)) {
 		if (fsck_user_confirmed(fs, "Continue? (Yes):", "Yes\n", 1)) {
@@ -2306,7 +2306,7 @@ static void after_pass_0(reiserfs_filsys_t *fs)
 		save_pass_0_result(fs);
 
 	id_map_free(proper_id_map(fs));
-	proper_id_map(fs) = 0;
+	proper_id_map(fs) = NULL;
 
 	time(&t);
 	fsck_progress("###########\n"
diff --git a/fsck/pass1.c b/fsck/pass1.c
index ee0076f..b7117de 100644
--- a/fsck/pass1.c
+++ b/fsck/pass1.c
@@ -115,7 +115,8 @@ static void indirect_in_tree(struct buffer_head *bh, struct item_head *ih)
 
 static void leaf_is_in_tree_now(struct buffer_head *bh)
 {
-	item_action_t actions[] = { stat_data_in_tree, indirect_in_tree, 0, 0 };
+	item_action_t actions[] = { stat_data_in_tree, indirect_in_tree,
+				    NULL, NULL };
 
 	mark_block_used((bh)->b_blocknr, 1);
 
@@ -136,7 +137,7 @@ static void insert_pointer(struct buffer_head *bh, struct reiserfs_path *path)
 	init_tb_struct(&tb, fs, path, 0x7fff);
 
 	/* fix_nodes & do_balance must work for internal nodes only */
-	ih = 0;
+	ih = NULL;
 
 	retval = fix_nodes( /*tb.transaction_handle, */ M_INTERNAL, &tb, ih);
 	if (retval != CARRY_ON)
@@ -149,12 +150,12 @@ static void insert_pointer(struct buffer_head *bh, struct reiserfs_path *path)
 	if (PATH_LAST_POSITION(path) == 0 && path->pos_in_item == 0)
 		PATH_H_B_ITEM_ORDER(path, 0) = -1;
 	else {
-		if (PATH_H_PPARENT(path, 0) == 0)
+		if (PATH_H_PPARENT(path, 0) == NULL)
 			PATH_H_B_ITEM_ORDER(path, 0) = 0;
 /*    PATH_H_B_ITEM_ORDER (path, 0) = PATH_H_PPARENT (path, 0) ? PATH_H_B_ITEM_ORDER (path, 0) : 0;*/
 	}
 
-	ih = 0;
+	ih = NULL;
 	body = (char *)bh;
 	//memmode = 0;
 
@@ -192,7 +193,7 @@ int balance_condition_2_fails(struct buffer_head *new,
 	/* new node can not be joined with its left neighbor */
 
 	right_dkey = uget_rkey(path);
-	if (right_dkey == 0)
+	if (right_dkey == NULL)
 		/* there is no right neighbor */
 		return 0;
 
@@ -293,7 +294,8 @@ static void try_to_insert_pointer_to_leaf(struct buffer_head *new_bh)
 		if (balance_condition_fails(new_bh, bh))
 			goto cannot_insert;
 
-		if (uget_lkey(&path) != 0 || PATH_LAST_POSITION(&path) != 0)
+		if (uget_lkey(&path) != NULL ||
+		    PATH_LAST_POSITION(&path) != 0)
 			die("try_to_insert_pointer_to_leaf: bad search result");
 
 		path.pos_in_item = 0;
@@ -808,7 +810,7 @@ static void after_pass_1(reiserfs_filsys_t *fs)
 	if (proper_id_map(fs)) {
 		/* when we run pass 1 only - we do not have proper_id_map */
 		id_map_free(proper_id_map(fs));
-		proper_id_map(fs) = 0;
+		proper_id_map(fs) = NULL;
 	}
 
 	time(&t);
diff --git a/fsck/pass2.c b/fsck/pass2.c
index db300ac..8c718c2 100644
--- a/fsck/pass2.c
+++ b/fsck/pass2.c
@@ -143,7 +143,7 @@ void save_item(struct si **head, struct item_head *ih, char *item,
 	memcpy(&(si->si_ih), ih, IH_SIZE);
 	memcpy(si->si_dnm_data, item, get_ih_item_len(ih));
 
-	if (*head == 0)
+	if (*head == NULL)
 		*head = si;
 	else {
 		cur = *head;
@@ -503,7 +503,7 @@ static void do_pass_2(reiserfs_filsys_t *fs)
 		       reiserfs_bitmap_find_zero_bit(fsck_uninsertables(fs),
 						     &j) == 0) {
 			bh = bread(fs->fs_dev, j, fs->fs_blocksize);
-			if (bh == 0) {
+			if (bh == NULL) {
 				fsck_log
 				    ("pass_2: Reading of the block (%lu) failed on the device 0x%x\n",
 				     j, fs->fs_dev);
@@ -606,7 +606,7 @@ static void after_pass_2(reiserfs_filsys_t *fs)
 		save_pass_2_result(fs);
 
 	id_map_free(proper_id_map(fs));
-	proper_id_map(fs) = 0;
+	proper_id_map(fs) = NULL;
 
 	reiserfs_delete_bitmap(fsck_new_bitmap(fs));
 	reiserfs_delete_bitmap(fsck_allocable_bitmap(fs));
diff --git a/fsck/semantic_check.c b/fsck/semantic_check.c
index ebd61b8..291d491 100644
--- a/fsck/semantic_check.c
+++ b/fsck/semantic_check.c
@@ -283,7 +283,7 @@ start_again:
 			one_more_corruption(fs, FIXABLE);
 			fsck_log("\n");
 			if (retval == DIRECTORY_NOT_FOUND)
-				return 0;
+				return NULL;
 		}
 	}
 
@@ -461,7 +461,7 @@ static int check_semantic_pass(struct reiserfs_key *key,
 
 		retval =
 		    check_check_regular_file(&path, sd,
-					     /* relocate ? new_ih : */ 0);
+					     /* relocate ? new_ih : */ NULL);
 		pathrelse(&path);
 		return retval;
 	}
@@ -538,11 +538,11 @@ static int check_semantic_pass(struct reiserfs_key *key,
 	dir_size = 0;
 	while ((dir_item =
 		get_next_directory_item(&next_item_key, parent, &tmp_ih,
-					&pos_in_item, dir_format)) != 0) {
+					&pos_in_item, dir_format)) != NULL) {
 		/* dir_item is copy of the item in separately allocated memory,
 		   item_key is a key of next item in the tree */
 		int i;
-		char *name = 0;
+		char *name = NULL;
 		int namelen, entry_len;
 		struct reiserfs_de_head *deh =
 		    (struct reiserfs_de_head *)dir_item + pos_in_item;
@@ -554,7 +554,7 @@ static int check_semantic_pass(struct reiserfs_key *key,
 
 			if (name) {
 				free(name);
-				name = 0;
+				name = NULL;
 			}
 
 			namelen = name_in_entry_length(&tmp_ih, deh, i);
@@ -701,7 +701,7 @@ static int check_semantic_pass(struct reiserfs_key *key,
 
 		freemem(dir_item);
 		free(name);
-		name = 0;
+		name = NULL;
 
 		if (not_of_one_file(&next_item_key, key))
 			/* next key is not of this directory */
@@ -895,7 +895,7 @@ void semantic_check(void)
 
 	check_safe_links();
 
-	if (check_semantic_pass(&root_dir_key, &parent_root_dir_key, 0, 0) !=
+	if (check_semantic_pass(&root_dir_key, &parent_root_dir_key, 0, NULL) !=
 	    OK) {
 		fsck_log("check_semantic_tree: No root directory found");
 		one_more_corruption(fs, FATAL);
diff --git a/fsck/semantic_rebuild.c b/fsck/semantic_rebuild.c
index d5f4568..f7c2af6 100644
--- a/fsck/semantic_rebuild.c
+++ b/fsck/semantic_rebuild.c
@@ -332,7 +332,7 @@ void relocate_dir(struct item_head *ih, int change_ih)
 	key = ih->ih_key;
 	set_type_and_offset(KEY_FORMAT_1, &key, SD_OFFSET, TYPE_STAT_DATA);
 
-	si = 0;
+	si = NULL;
 	while (1) {
 		reiserfs_search_by_key_4(fs, &key, &path);
 
@@ -582,7 +582,7 @@ static char *get_next_directory_item(struct reiserfs_key *key,	/* on return this
 			    ("get_next_directory_item: The entry \"..\" cannot be found in %k\n",
 			     &ih->ih_key);
 			pathrelse(&path);
-			return 0;
+			return NULL;
 		}
 	}
 
@@ -796,7 +796,7 @@ start_again:			/* when directory was relocated */
 	if (not_a_directory(sd)) {
 		retval =
 		    rebuild_check_regular_file(&path, sd,
-					       relocate ? new_ih : 0);
+					       relocate ? new_ih : NULL);
 		pathrelse(&path);
 		return retval;
 	}
@@ -901,11 +901,11 @@ start_again:			/* when directory was relocated */
 	dir_size = 0;
 	while ((dir_item =
 		get_next_directory_item(&item_key, parent, &tmp_ih,
-					&pos_in_item)) != 0) {
+					&pos_in_item)) != NULL) {
 		/* dir_item is copy of the item in separately allocated memory,
 		   item_key is a key of next item in the tree */
 		int i;
-		char *name = 0;
+		char *name = NULL;
 		int namelen, entry_len;
 		struct reiserfs_de_head *deh =
 		    (struct reiserfs_de_head *)dir_item + pos_in_item;
@@ -916,7 +916,7 @@ start_again:			/* when directory was relocated */
 
 			if (name) {
 				free(name);
-				name = 0;
+				name = NULL;
 			}
 
 			namelen = name_in_entry_length(&tmp_ih, deh, i);
@@ -1030,7 +1030,7 @@ start_again:			/* when directory was relocated */
 
 		freemem(dir_item);
 		free(name);
-		name = 0;
+		name = NULL;
 
 		if (not_of_one_file(&item_key, key))
 			/* next key is not of this directory */
@@ -1302,7 +1302,7 @@ static void after_pass_3(reiserfs_filsys_t *fs)
 	save_rebuild_semantic_result(fs);
 
 	id_map_free(proper_id_map(fs));
-	proper_id_map(fs) = 0;
+	proper_id_map(fs) = NULL;
 
 	fs->fs_dirt = 1;
 	reiserfs_close(fs);
@@ -1333,7 +1333,7 @@ void pass_3_semantic(reiserfs_filsys_t *fs)
 	link_relocated_files();
 
 	rebuild_semantic_pass(&root_dir_key, &parent_root_dir_key,
-			      0 /*!dot_dot */ , 0 /*reloc_ih */ );
+			      0 /*!dot_dot */ , NULL /*reloc_ih */ );
 
 	add_badblock_list(fs, 1);
 
diff --git a/fsck/super.c b/fsck/super.c
index 39fae80..d1794a0 100644
--- a/fsck/super.c
+++ b/fsck/super.c
@@ -17,7 +17,7 @@
 int what_fs_version()
 {
 	size_t n = 0;
-	char *answer = 0;
+	char *answer = NULL;
 	int version;
 	printf("\nwhat the version of ReiserFS do you use[1-4]\n"
 	       "\t(1)   3.6.x\n"
@@ -171,8 +171,8 @@ int check_sb (reiserfs_filsys_t *fs) {
 void rebuild_sb(reiserfs_filsys_t *fs, char *filename, struct fsck_data *data)
 {
 	int version = 0;
-	struct reiserfs_super_block *ondisk_sb = 0;
-	struct reiserfs_super_block *sb = 0;
+	struct reiserfs_super_block *ondisk_sb = NULL;
+	struct reiserfs_super_block *sb = NULL;
 	struct reiserfs_journal_header *j_head;
 
 	int magic_was_found = 0;
@@ -182,11 +182,11 @@ void rebuild_sb(reiserfs_filsys_t *fs, char *filename, struct fsck_data *data)
 	__u32 p_jp_journal_1st_block = 0;
 	__u32 p_jp_dev_size = 0;
 	int standard_journal = -1;
-	char *journal_dev_name = 0;
+	char *journal_dev_name = NULL;
 	char *tmp;
 	int sb_size;
 
-	char *answer = 0;
+	char *answer = NULL;
 	size_t n = 0;
 	struct stat stat_buf;
 	int retval, exit_code = EXIT_OK;
@@ -525,7 +525,7 @@ void rebuild_sb(reiserfs_filsys_t *fs, char *filename, struct fsck_data *data)
 		set_sb_tree_height(sb, 0);
 	}
 
-	if (get_sb_hash_code(sb) && code2name(get_sb_hash_code(sb)) == 0) {
+	if (get_sb_hash_code(sb) && code2name(get_sb_hash_code(sb)) == NULL) {
 		fsck_log("rebuild-sb: wrong hash occured (%lu), zeroed\n",
 			 get_sb_hash_code(sb));
 
diff --git a/fsck/ufile.c b/fsck/ufile.c
index 68add8a..9053e3a 100644
--- a/fsck/ufile.c
+++ b/fsck/ufile.c
@@ -37,7 +37,7 @@ static unsigned long indirect_to_direct(struct reiserfs_path *path, __u64 len,
 	struct buffer_head *bh = PATH_PLAST_BUFFER(path);
 	struct item_head *ih = tp_item_head(path);
 	__u32 unfm_ptr;
-	struct buffer_head *unfm_bh = 0;
+	struct buffer_head *unfm_bh = NULL;
 	struct item_head ins_ih;
 	char *buf;
 	char bad_drct[fs->fs_blocksize];
diff --git a/include/reiserfs_lib.h b/include/reiserfs_lib.h
index 606d076..2f02ec9 100644
--- a/include/reiserfs_lib.h
+++ b/include/reiserfs_lib.h
@@ -280,7 +280,7 @@ typedef int (*check_unfm_func_t) (reiserfs_filsys_t *, __u32);
 int is_it_bad_item(reiserfs_filsys_t *, struct item_head *, char *,
 		   check_unfm_func_t, int bad_dir);
 
-#define hash_func_is_unknown(fs) ((fs)->fs_hash_function == 0)
+#define hash_func_is_unknown(fs) ((fs)->fs_hash_function == NULL)
 #define reiserfs_hash(fs) ((fs)->fs_hash_function)
 
 int known_hashes(void);
diff --git a/lib/io.c b/lib/io.c
index 9d319ed..ae11402 100644
--- a/lib/io.c
+++ b/lib/io.c
@@ -143,13 +143,13 @@ static void insert_into_hash_queue(struct buffer_head *bh)
 
 static void remove_from_hash_queue(struct buffer_head *bh)
 {
-	if (bh->b_hash_next == 0 && bh->b_hash_prev == 0
+	if (bh->b_hash_next == NULL && bh->b_hash_prev == NULL
 	    && bh != g_a_hash_queues[bh->b_blocknr % NR_HASH_QUEUES])
 		/* (b_dev == -1) ? */
 		return;
 
 	if (bh == g_a_hash_queues[bh->b_blocknr % NR_HASH_QUEUES]) {
-		if (bh->b_hash_prev != 0)
+		if (bh->b_hash_prev)
 			die("remove_from_hash_queue: hash queue corrupted");
 		g_a_hash_queues[bh->b_blocknr % NR_HASH_QUEUES] =
 		    bh->b_hash_next;
@@ -160,18 +160,18 @@ static void remove_from_hash_queue(struct buffer_head *bh)
 	if (bh->b_hash_prev)
 		bh->b_hash_prev->b_hash_next = bh->b_hash_next;
 
-	bh->b_hash_prev = bh->b_hash_next = 0;
+	bh->b_hash_prev = bh->b_hash_next = NULL;
 }
 
 static void put_buffer_list_end(struct buffer_head **list,
 				struct buffer_head *bh)
 {
-	struct buffer_head *last = 0;
+	struct buffer_head *last = NULL;
 
 	if (bh->b_prev || bh->b_next)
 		die("put_buffer_list_end: buffer list corrupted");
 
-	if (*list == 0) {
+	if (*list == NULL) {
 		bh->b_next = bh;
 		bh->b_prev = bh;
 		*list = bh;
@@ -189,7 +189,7 @@ static void remove_from_buffer_list(struct buffer_head **list,
 				    struct buffer_head *bh)
 {
 	if (bh == bh->b_next) {
-		*list = 0;
+		*list = NULL;
 	} else {
 		bh->b_prev->b_next = bh->b_next;
 		bh->b_next->b_prev = bh->b_prev;
@@ -197,7 +197,7 @@ static void remove_from_buffer_list(struct buffer_head **list,
 			*list = bh->b_next;
 	}
 
-	bh->b_next = bh->b_prev = 0;
+	bh->b_next = bh->b_prev = NULL;
 }
 
 static void put_buffer_list_head(struct buffer_head **list,
@@ -255,13 +255,13 @@ static int grow_buffers(int size)
 	bh = (struct buffer_head *)getmem(GROW_BUFFERS__NEW_BUFERS_PER_CALL *
 					  sizeof(struct buffer_head) +
 					  sizeof(struct buffer_head *));
-	if (g_buffer_heads == 0)
+	if (!g_buffer_heads)
 		g_buffer_heads = bh;
 	else {
 		/* link new array to the end of array list */
 		tmp = g_buffer_heads;
 		while (*(struct buffer_head **)
-		       (tmp + GROW_BUFFERS__NEW_BUFERS_PER_CALL) != 0)
+		       (tmp + GROW_BUFFERS__NEW_BUFERS_PER_CALL) != NULL)
 			tmp =
 			    *(struct buffer_head **)(tmp +
 						     GROW_BUFFERS__NEW_BUFERS_PER_CALL);
@@ -275,7 +275,7 @@ static int grow_buffers(int size)
 		tmp = bh + i;
 		memset(tmp, 0, sizeof(struct buffer_head));
 		tmp->b_data = getmem(size);
-		if (tmp->b_data == 0)
+		if (!tmp->b_data)
 			die("grow_buffers: no memory for new buffer data");
 		tmp->b_dev = -1;
 		tmp->b_size = size;
@@ -313,7 +313,7 @@ static struct buffer_head *get_free_buffer(struct buffer_head **list,
 
 	next = *list;
 	if (!next)
-		return 0;
+		return NULL;
 
 	for (;;) {
 		if (!next)
@@ -328,7 +328,7 @@ static struct buffer_head *get_free_buffer(struct buffer_head **list,
 		if (next == *list)
 			break;
 	}
-	return 0;
+	return NULL;
 }
 
 /* to_write == 0 when all blocks have to be flushed. Otherwise - write only
@@ -441,7 +441,7 @@ struct buffer_head *getblk(int dev, unsigned long block, int size)
 
 void brelse(struct buffer_head *bh)
 {
-	if (bh == 0)
+	if (!bh)
 		return;
 
 	if (bh->b_count == 0)
@@ -486,7 +486,7 @@ struct buffer_head *bread(int dev, unsigned long block, size_t size)
 	int ret;
 
 	if (is_bad_block(block))
-		return 0;
+		return NULL;
 
 	bh = getblk(dev, block, size);
 
@@ -524,7 +524,7 @@ struct buffer_head *bread(int dev, unsigned long block, size_t size)
 
 static struct block_handler *rollback_blocks_array;
 static __u32 rollback_blocks_number = 0;
-static FILE *s_rollback_file = 0;
+static FILE *s_rollback_file = NULL;
 static FILE *log_file;
 static int do_rollback = 0;
 
@@ -609,7 +609,7 @@ int open_rollback_file(char *rollback_file, FILE * log)
 			"Specified file (%s) does not look like a rollback file\n",
 			rollback_file);
 		fclose(s_rollback_file);
-		s_rollback_file = 0;
+		s_rollback_file = NULL;
 		return -1;
 	}
 
@@ -632,7 +632,7 @@ int open_rollback_file(char *rollback_file, FILE * log)
 
 void close_rollback_file()
 {
-	if (s_rollback_file == 0)
+	if (!s_rollback_file)
 		return;
 
 	if (!do_rollback) {
@@ -641,7 +641,7 @@ void close_rollback_file()
 			return;
 		fwrite(&rollback_blocks_number, sizeof(rollback_blocksize), 1,
 		       s_rollback_file);
-		if (log_file != 0)
+		if (log_file)
 			fprintf(log_file, "rollback: %u blocks backed up\n",
 				rollback_blocks_number);
 	}
@@ -774,7 +774,7 @@ void do_fsck_rollback(int fd_device, int fd_journal_device, FILE * progress)
 	}
 
 	printf("\n");
-	if (log_file != 0)
+	if (log_file)
 		fprintf(log_file, "rollback: (%u) blocks restored\n",
 			count_rollbacked);
 }
diff --git a/lib/misc.c b/lib/misc.c
index 409a219..f9a1580 100644
--- a/lib/misc.c
+++ b/lib/misc.c
@@ -269,7 +269,7 @@ static int misc_root_mounted(char *device)
 
 static int misc_file_ro(char *file)
 {
-	if (utime(file, 0) == -1) {
+	if (utime(file, NULL) == -1) {
 		if (errno == EROFS)
 			return 1;
 	}
@@ -584,7 +584,7 @@ __u64 mask64(int from, int count)
 
 __u32 get_random(void)
 {
-	srandom(time(0));
+	srandom(time(NULL));
 	return random();
 }
 
@@ -815,7 +815,7 @@ void clean_after_dma_check(int fd, dma_info_t *dma_info)
 
 int user_confirmed(FILE * fp, char *q, char *yes)
 {
-	char *answer = 0;
+	char *answer = NULL;
 	size_t n = 0;
 
 	fprintf(fp, "%s", q);
diff --git a/lib/parse_time.c b/lib/parse_time.c
index 13acca6..f8e3929 100644
--- a/lib/parse_time.c
+++ b/lib/parse_time.c
@@ -15,7 +15,7 @@ time_t parse_time(char *str)
 	struct tm ts;
 
 	if (strcmp(str, "now") == 0) {
-		return (time(0));
+		return (time(NULL));
 	}
 	memset(&ts, 0, sizeof(ts));
 #ifdef HAVE_STRPTIME
diff --git a/mkreiserfs/mkreiserfs.c b/mkreiserfs/mkreiserfs.c
index 0f9a5ab..dc8400b 100644
--- a/mkreiserfs/mkreiserfs.c
+++ b/mkreiserfs/mkreiserfs.c
@@ -568,17 +568,17 @@ int main(int argc, char **argv)
 
 	while (1) {
 		static struct option options[] = {
-			{"block-size", required_argument, 0, 'b'},
-			{"journal-device", required_argument, 0, 'j'},
-			{"journal-size", required_argument, 0, 's'},
-			{"transaction-max-size", required_argument, 0, 't'},
-			{"journal-offset", required_argument, 0, 'o'},
-			{"badblocks", required_argument, 0, 'B'},
-			{"hash", required_argument, 0, 'h'},
-			{"uuid", required_argument, 0, 'u'},
-			{"label", required_argument, 0, 'l'},
+			{"block-size", required_argument, NULL, 'b'},
+			{"journal-device", required_argument, NULL, 'j'},
+			{"journal-size", required_argument, NULL, 's'},
+			{"transaction-max-size", required_argument, NULL, 't'},
+			{"journal-offset", required_argument, NULL, 'o'},
+			{"badblocks", required_argument, NULL, 'B'},
+			{"hash", required_argument, NULL, 'h'},
+			{"uuid", required_argument, NULL, 'u'},
+			{"label", required_argument, NULL, 'l'},
 			{"format", required_argument, &flag, 1},
-			{0, 0, 0, 0}
+			{}
 		};
 		int option_index;
 
diff --git a/reiserfscore/bitmap.c b/reiserfscore/bitmap.c
index 96c61df..7bb3ab1 100644
--- a/reiserfscore/bitmap.c
+++ b/reiserfscore/bitmap.c
@@ -17,14 +17,14 @@ reiserfs_bitmap_t *reiserfs_create_bitmap(unsigned int bit_count)
 
 	bm = getmem(sizeof(*bm));
 	if (!bm)
-		return 0;
+		return NULL;
 	bm->bm_bit_size = bit_count;
 	bm->bm_byte_size = ((unsigned long long)bit_count + 7) / 8;
 	bm->bm_set_bits = 0;
 	bm->bm_map = getmem(bm->bm_byte_size);
 	if (!bm->bm_map) {
 		freemem(bm);
-		return 0;
+		return NULL;
 	}
 
 	return bm;
@@ -420,7 +420,7 @@ FILE *open_file(char *filename, char *option)
 	if (!fp) {
 		reiserfs_warning(stderr, "open_file: could not open file %s\n",
 				 filename);
-		return 0;
+		return NULL;
 	}
 	reiserfs_warning(stderr, "Temp file opened by fsck: \"%s\" .. \n",
 			 filename);
@@ -622,7 +622,7 @@ reiserfs_bitmap_t *reiserfs_bitmap_load(FILE * fp)
 		reiserfs_warning(stderr, "reiserfs_bitmap_load: "
 				 "no bitmap start magic found");
 //      fclose (fp);
-		return 0;
+		return NULL;
 	}
 
 	/* read bit size of bitmap */
@@ -633,7 +633,7 @@ reiserfs_bitmap_t *reiserfs_bitmap_load(FILE * fp)
 		reiserfs_warning(stderr,
 				 "reiserfs_bitmap_load: creation failed");
 //      fclose (fp);
-		return 0;
+		return NULL;
 	}
 
 	/*printf ("LOAD: bit_size - %d\n", v); */
@@ -665,7 +665,7 @@ reiserfs_bitmap_t *reiserfs_bitmap_load(FILE * fp)
 	if (v != BITMAP_END_MAGIC) {
 		reiserfs_warning(stderr, "reiserfs_bitmap_load: "
 				 "no bitmap end magic found");
-		return 0;
+		return NULL;
 	}
 
 	/*    reiserfs_warning (stderr, "%d bits set - done\n", reiserfs_bitmap_ones (bm)); */
@@ -692,7 +692,7 @@ void reiserfs_free_ondisk_bitmap(reiserfs_filsys_t *fs)
 {
 	if (fs->fs_bitmap2) {
 		reiserfs_delete_bitmap(fs->fs_bitmap2);
-		fs->fs_bitmap2 = 0;
+		fs->fs_bitmap2 = NULL;
 	}
 }
 
diff --git a/reiserfscore/do_balan.c b/reiserfscore/do_balan.c
index bdb8517..ec69e6b 100644
--- a/reiserfscore/do_balan.c
+++ b/reiserfscore/do_balan.c
@@ -143,9 +143,9 @@ static int balance_leaf_when_delete(	/*struct reiserfs_transaction_handle *th, *
 					return 0;
 				}
 				/* all contents of all the 3 buffers will be in R[0] */
-				leaf_move_items(LEAF_FROM_S_TO_R, tb, n, -1, 0);
+				leaf_move_items(LEAF_FROM_S_TO_R, tb, n, -1, NULL);
 				leaf_move_items(LEAF_FROM_L_TO_R, tb,
-						B_NR_ITEMS(tb->L[0]), -1, 0);
+						B_NR_ITEMS(tb->L[0]), -1, NULL);
 
 				/* right_delimiting_key is correct in R[0] */
 				replace_key(tb->tb_fs, tb->CFR[0], tb->rkey[0],
@@ -1402,7 +1402,7 @@ struct buffer_head *get_FEB(struct tree_balance *tb)
 	struct buffer_info bi;
 
 	for (i = 0; i < MAX_FEB_SIZE; i++)
-		if (tb->FEB[i] != 0)
+		if (tb->FEB[i] != NULL)
 			break;
 
 	if (i == MAX_FEB_SIZE)
@@ -1413,7 +1413,7 @@ struct buffer_head *get_FEB(struct tree_balance *tb)
 	make_empty_node(&bi);
 	misc_set_bit(BH_Uptodate, &first_b->b_state);
 
-	tb->FEB[i] = 0;
+	tb->FEB[i] = NULL;
 	tb->used[i] = first_b;
 
 	return (first_b);
diff --git a/reiserfscore/fix_node.c b/reiserfscore/fix_node.c
index f09fe58..c2467ff 100644
--- a/reiserfscore/fix_node.c
+++ b/reiserfscore/fix_node.c
@@ -918,7 +918,7 @@ static struct buffer_head *get_left_neighbor(reiserfs_filsys_t *s,
 	search_by_key(s, &key, &path_to_left_neighbor, DISK_LEAF_NODE_LEVEL);
 	if (PATH_LAST_POSITION(&path_to_left_neighbor) == 0) {
 		pathrelse(&path_to_left_neighbor);
-		return 0;
+		return NULL;
 	}
 	bh = PATH_PLAST_BUFFER(&path_to_left_neighbor);
 	bh->b_count++;
@@ -946,7 +946,7 @@ static struct buffer_head *get_right_neighbor(reiserfs_filsys_t *s,
 	if (PATH_PLAST_BUFFER(&path_to_right_neighbor) ==
 	    PATH_PLAST_BUFFER(path)) {
 		pathrelse(&path_to_right_neighbor);
-		return 0;
+		return NULL;
 	}
 	bh = PATH_PLAST_BUFFER(&path_to_right_neighbor);
 	bh->b_count++;
@@ -963,7 +963,7 @@ int is_left_mergeable(reiserfs_filsys_t *s, struct reiserfs_path *path)
 	right = item_head(PATH_PLAST_BUFFER(path), 0);
 
 	bh = get_left_neighbor(s, path);
-	if (bh == 0) {
+	if (bh == NULL) {
 		return 0;
 	}
 	retval =
@@ -984,7 +984,7 @@ int is_right_mergeable(reiserfs_filsys_t *s, struct reiserfs_path *path)
 			   B_NR_ITEMS(PATH_PLAST_BUFFER(path)) - 1);
 
 	bh = get_right_neighbor(s, path);
-	if (bh == 0) {
+	if (bh == NULL) {
 		return 0;
 	}
 	retval = are_items_mergeable(left, item_head(bh, 0), bh->b_size);
@@ -1221,7 +1221,8 @@ static int get_lfree(struct tree_balance *tb, int h)
 	struct buffer_head *l, *f;
 	int order;
 
-	if ((f = PATH_H_PPARENT(tb->tb_path, h)) == 0 || (l = tb->FL[h]) == 0)
+	if ((f = PATH_H_PPARENT(tb->tb_path, h)) == NULL ||
+	    (l = tb->FL[h]) == NULL)
 		return 0;
 
 	if (f == l)
@@ -1247,7 +1248,8 @@ static int get_rfree(struct tree_balance *tb, int h)
 	struct buffer_head *r, *f;
 	int order;
 
-	if ((f = PATH_H_PPARENT(tb->tb_path, h)) == 0 || (r = tb->FR[h]) == 0)
+	if ((f = PATH_H_PPARENT(tb->tb_path, h)) == NULL ||
+	    (r = tb->FR[h]) == NULL)
 		return 0;
 
 	if (f == r)
diff --git a/reiserfscore/journal.c b/reiserfscore/journal.c
index 6acb408..70f9a52 100644
--- a/reiserfscore/journal.c
+++ b/reiserfscore/journal.c
@@ -786,9 +786,9 @@ void reiserfs_free_journal(reiserfs_filsys_t *fs)
 	if (!reiserfs_journal_opened(fs))
 		return;
 	brelse(fs->fs_jh_bh);
-	fs->fs_jh_bh = 0;
+	fs->fs_jh_bh = NULL;
 	free(fs->fs_j_file_name);
-	fs->fs_j_file_name = 0;
+	fs->fs_j_file_name = NULL;
 }
 
 void reiserfs_close_journal(reiserfs_filsys_t *fs)
diff --git a/reiserfscore/lbalance.c b/reiserfscore/lbalance.c
index c477fa7..afd7f92 100644
--- a/reiserfscore/lbalance.c
+++ b/reiserfscore/lbalance.c
@@ -52,7 +52,7 @@ static void leaf_copy_dir_entries(struct buffer_info *dest_bi,
 		    get_deh_location(&deh[from + copy_count - 1]);
 	} else {
 		copy_records_len = 0;
-		records = 0;
+		records = NULL;
 	}
 
 	/* when copy last to first, dest buffer can contain 0 items */
@@ -570,7 +570,7 @@ int leaf_shift_left(struct tree_balance *tb, int shift_num, int shift_bytes)
 	int i;
 
 	/* move shift_num (and shift_bytes bytes) items from S[0] to left neighbor L[0] */
-	i = leaf_move_items(LEAF_FROM_S_TO_L, tb, shift_num, shift_bytes, 0);
+	i = leaf_move_items(LEAF_FROM_S_TO_L, tb, shift_num, shift_bytes, NULL);
 
 	if (shift_num) {
 		if (B_NR_ITEMS(S0) == 0) {
@@ -597,7 +597,7 @@ int leaf_shift_right(struct tree_balance *tb, int shift_num, int shift_bytes)
 
 	/* move shift_num (and shift_bytes) items from S[0] to right neighbor R[0] */
 	ret_value =
-	    leaf_move_items(LEAF_FROM_S_TO_R, tb, shift_num, shift_bytes, 0);
+	    leaf_move_items(LEAF_FROM_S_TO_R, tb, shift_num, shift_bytes, NULL);
 
 	/* replace rkey in CFR[0] by the 0-th key from R[0] */
 	if (shift_num) {
diff --git a/reiserfscore/node_formats.c b/reiserfscore/node_formats.c
index dda3990..213aeda 100644
--- a/reiserfscore/node_formats.c
+++ b/reiserfscore/node_formats.c
@@ -520,7 +520,7 @@ static const struct {
 	hashf_t func;
 	char *name;
 } hashes[] = { {
-0, "not set"}, {
+NULL, "not set"}, {
 keyed_hash, "\"tea\""}, {
 yura_hash, "\"rupasov\""}, {
 r5_hash, "\"r5\""}};
@@ -563,7 +563,7 @@ int is_properly_hashed(reiserfs_filsys_t *fs,
 					fprintf(stderr,
 						"Detecting hash code: could not detect hash with name \"%.*s\"\n",
 						namelen, name);
-					reiserfs_hash(fs) = 0;
+					reiserfs_hash(fs) = NULL;
 					return 1;
 				}
 
@@ -611,7 +611,7 @@ int find_hash_in_use(char *name, int namelen, __u32 offset,
 char *code2name(unsigned int code)
 {
 	if (code >= HASH_AMOUNT || code < 0)
-		return 0;
+		return NULL;
 	return hashes[code].name;
 }
 
@@ -645,7 +645,7 @@ hashf_t name2func(char *hash)
 	for (i = 0; i < HASH_AMOUNT; i++)
 		if (!strcmp(hash, hashes[i].name))
 			return hashes[i].func;
-	return 0;
+	return NULL;
 }
 
 int dir_entry_bad_location(struct reiserfs_de_head *deh, struct item_head *ih,
diff --git a/reiserfscore/prints.c b/reiserfscore/prints.c
index b15fd4d..e579601 100644
--- a/reiserfscore/prints.c
+++ b/reiserfscore/prints.c
@@ -456,7 +456,7 @@ void reiserfs_print_item(FILE * fp, struct buffer_head *bh,
 		return;
 	}
 
-	print_directory_item(fp, 0, bh, ih);
+	print_directory_item(fp, NULL, bh, ih);
 }
 
 /* this prints internal nodes (4 keys/items in line) (dc_number,
@@ -813,8 +813,8 @@ void print_tb(int mode, int item_pos, int pos_in_item, struct tree_balance *tb,
 		} else {
 			/*      printk ("print_tb: h=%d, PATH_H_PATH_OFFSET=%d, path_length=%d\n",
 			   h, PATH_H_PATH_OFFSET (tb->tb_path, h), tb->tb_path->path_length); */
-			tbSh = 0;
-			tbFh = 0;
+			tbSh = NULL;
+			tbFh = NULL;
 		}
 		printf
 		    ("* %u * %3lu(%2lu) * %3lu(%2lu) * %3lu(%2lu) * %5lu * %5lu * %5lu * %5lu * %5lu *\n",
diff --git a/reiserfscore/reiserfslib.c b/reiserfscore/reiserfslib.c
index cba2b0f..c70ddff 100644
--- a/reiserfscore/reiserfslib.c
+++ b/reiserfscore/reiserfslib.c
@@ -76,7 +76,7 @@ reiserfs_filsys_t *reiserfs_open(const char *filename, int flags,
 	if (fd == -1) {
 		if (error)
 			*error = errno;
-		return 0;
+		return NULL;
 	}
 
 	fs = getmem(sizeof(*fs));
@@ -160,7 +160,7 @@ found:
 					 "reiserfs_open: bread failed reading block %d, size %d\n",
 					 i, fs->fs_blocksize);
 			freemem(fs);
-			return 0;
+			return NULL;
 		}
 		sb = (struct reiserfs_super_block *)bh->b_data;
 	}
@@ -199,7 +199,7 @@ reiserfs_filsys_t *reiserfs_create(char *filename,
 	if (count_blocks(filename, block_size) < block_count) {
 		reiserfs_warning(stderr,
 				 "reiserfs_create: no enough blocks on device\n");
-		return 0;
+		return NULL;
 	}
 
 	if (!is_block_count_correct(REISERFS_DISK_OFFSET_IN_BYTES / block_size,
@@ -207,13 +207,13 @@ reiserfs_filsys_t *reiserfs_create(char *filename,
 		reiserfs_warning(stderr,
 				 "reiserfs_create: can not create that small "
 				 "(%u blocks) filesystem\n", block_count);
-		return 0;
+		return NULL;
 	}
 
 	fs = getmem(sizeof(*fs));
 	if (!fs) {
 		reiserfs_warning(stderr, "reiserfs_create: getmem failed\n");
-		return 0;
+		return NULL;
 	}
 
 	fs->fs_dev = open(filename, O_RDWR | O_EXCL
@@ -226,7 +226,7 @@ reiserfs_filsys_t *reiserfs_create(char *filename,
 				 "reiserfs_create: could not open %s: %s\n",
 				 filename, strerror(errno));
 		freemem(fs);
-		return 0;
+		return NULL;
 	}
 
 	fs->fs_blocksize = block_size;
@@ -244,7 +244,7 @@ reiserfs_filsys_t *reiserfs_create(char *filename,
 
 	if (!fs->fs_super_bh) {
 		reiserfs_warning(stderr, "reiserfs_create: getblk failed\n");
-		return 0;
+		return NULL;
 	}
 
 	mark_buffer_uptodate(fs->fs_super_bh, 1);
@@ -407,12 +407,12 @@ void reiserfs_free(reiserfs_filsys_t *fs)
 
 	/* release super block and memory used by filesystem handler */
 	brelse(fs->fs_super_bh);
-	fs->fs_super_bh = 0;
+	fs->fs_super_bh = NULL;
 
 	free_buffers();
 
 	free(fs->fs_file_name);
-	fs->fs_file_name = 0;
+	fs->fs_file_name = NULL;
 	freemem(fs);
 }
 
@@ -464,7 +464,7 @@ static int reiserfs_search_by_key_x(reiserfs_filsys_t *fs,
 		curr = PATH_OFFSET_PELEMENT(path, ++path->path_length);
 		bh = curr->pe_buffer =
 		    bread(fs->fs_dev, block, fs->fs_blocksize);
-		if (bh == 0) {
+		if (bh == NULL) {
 			path->path_length--;
 			pathrelse(path);
 			return ITEM_NOT_FOUND;
@@ -553,7 +553,7 @@ int reiserfs_search_by_position(reiserfs_filsys_t *s, struct reiserfs_key *key,
 			next_key = leaf_key(bh, PATH_LAST_POSITION(path));
 		else
 			next_key = uget_rkey(path);
-		if (next_key == 0 || not_of_one_file(next_key, key)) {
+		if (next_key == NULL || not_of_one_file(next_key, key)) {
 			/* there is no any part of such file in the tree */
 			path->pos_in_item = 0;
 			return FILE_NOT_FOUND;
@@ -642,7 +642,7 @@ struct reiserfs_key *uget_lkey(struct reiserfs_path *path)
 	}
 
 	/* there is no left delimiting key */
-	return 0;
+	return NULL;
 }
 
 struct reiserfs_key *uget_rkey(struct reiserfs_path *path)
@@ -679,7 +679,7 @@ struct reiserfs_key *uget_rkey(struct reiserfs_path *path)
 	}
 
 	/* there is no right delimiting key */
-	return 0;
+	return NULL;
 }
 
 struct reiserfs_key *reiserfs_next_key(struct reiserfs_path *path)
@@ -756,7 +756,8 @@ int reiserfs_search_by_entry_key(reiserfs_filsys_t *fs,
 			/* next item is in right neighboring node */
 			struct reiserfs_key *next_key = uget_rkey(path);
 
-			if (next_key == 0 || not_of_one_file(next_key, key)) {
+			if (next_key == NULL ||
+			    not_of_one_file(next_key, key)) {
 				/* there are no items of that directory */
 				path->pos_in_item = 0;
 				return DIRECTORY_NOT_FOUND;
@@ -821,22 +822,22 @@ int reiserfs_remove_entry(reiserfs_filsys_t *fs, struct reiserfs_key *key)
 	if (get_ih_entry_count(ih) == 1) {
 		init_tb_struct(&tb, fs, &path,
 			       -(IH_SIZE + get_ih_item_len(ih)));
-		if (fix_nodes(M_DELETE, &tb, 0) != CARRY_ON) {
+		if (fix_nodes(M_DELETE, &tb, NULL) != CARRY_ON) {
 			unfix_nodes(&tb);
 			return 1;
 		}
-		do_balance(&tb, 0, 0, M_DELETE, 0);
+		do_balance(&tb, NULL, NULL, M_DELETE, 0);
 		return 0;
 	}
 
 	deh = B_I_DEH(get_bh(&path), ih) + path.pos_in_item;
 	init_tb_struct(&tb, fs, &path,
 		       -(DEH_SIZE + entry_length(ih, deh, path.pos_in_item)));
-	if (fix_nodes(M_CUT, &tb, 0) != CARRY_ON) {
+	if (fix_nodes(M_CUT, &tb, NULL) != CARRY_ON) {
 		unfix_nodes(&tb);
 		return 1;
 	}
-	do_balance(&tb, 0, 0, M_CUT, 0);
+	do_balance(&tb, NULL, NULL, M_CUT, 0);
 	return 0;
 }
 
@@ -848,10 +849,10 @@ void reiserfs_paste_into_item(reiserfs_filsys_t *fs,
 
 	init_tb_struct(&tb, fs, path, size);
 
-	if (fix_nodes(M_PASTE, &tb, 0 /*ih */ ) != CARRY_ON)
+	if (fix_nodes(M_PASTE, &tb, NULL) != CARRY_ON)
 		reiserfs_panic("reiserfs_paste_into_item: fix_nodes failed");
 
-	do_balance(&tb, 0, body, M_PASTE, 0 /*zero num */ );
+	do_balance(&tb, NULL, body, M_PASTE, 0 /* zero num */ );
 }
 
 void reiserfs_insert_item(reiserfs_filsys_t *fs, struct reiserfs_path *path,
@@ -1081,7 +1082,7 @@ int reiserfs_add_entry(reiserfs_filsys_t *fs, struct reiserfs_key *dir,
 	int item_len;
 	__u32 hash;
 
-	if (reiserfs_find_entry(fs, dir, name, &gen_counter, 0))
+	if (reiserfs_find_entry(fs, dir, name, &gen_counter, NULL))
 		/* entry is in the directory already or directory was not found */
 		return 0;
 
@@ -1117,7 +1118,7 @@ int reiserfs_add_entry(reiserfs_filsys_t *fs, struct reiserfs_key *dir,
 	/* fsck may need to insert item which was not reached yet */
 	set_ih_flags(&entry_ih, fsck_need);
 
-	entry = make_entry(0, name, key, get_offset(&(entry_ih.ih_key)));
+	entry = make_entry(NULL, name, key, get_offset(&(entry_ih.ih_key)));
 
 	retval = reiserfs_search_by_entry_key(fs, &(entry_ih.ih_key), &path);
 	switch (retval) {
@@ -1401,11 +1402,10 @@ static void callback_badblock_rm(reiserfs_filsys_t *fs,
 		       -(IH_SIZE +
 			 get_ih_item_len(tp_item_head(badblock_path))));
 
-	if (fix_nodes(M_DELETE, &tb, 0) != CARRY_ON)
+	if (fix_nodes(M_DELETE, &tb, NULL) != CARRY_ON)
 		die("%s: fix_nodes failed", __FUNCTION__);
 
-	do_balance( /*tb.transaction_handle, */ &tb, 0, 0, M_DELETE,
-		   0 /*zero num */ );
+	do_balance(&tb, NULL, NULL, M_DELETE, 0 /* zero num */);
 }
 
 void mark_badblock(reiserfs_filsys_t *fs,
@@ -1490,10 +1490,10 @@ void add_badblock_list(reiserfs_filsys_t *fs, int replace)
 
 			init_tb_struct(&tb, fs, &badblock_path, UNFM_P_SIZE);
 
-			if (fix_nodes(M_PASTE, &tb, 0) != CARRY_ON)
+			if (fix_nodes(M_PASTE, &tb, NULL) != CARRY_ON)
 				die("reiserfsck_paste_into_item: fix_nodes failed");
 
-			do_balance(&tb, 0, (const char *)&ni, M_PASTE, 0);
+			do_balance(&tb, NULL, (const char *)&ni, M_PASTE, 0);
 			break;
 		}
 
diff --git a/reiserfscore/stree.c b/reiserfscore/stree.c
index b0a235f..8b2c013 100644
--- a/reiserfscore/stree.c
+++ b/reiserfscore/stree.c
@@ -372,7 +372,7 @@ int search_by_key(reiserfs_filsys_t *fs, struct reiserfs_key *p_s_key,	/* Key to
 		/* make sure, that the node contents look like a node of
 		   certain level */
 		if (!is_tree_node(p_s_bh, expected_level)) {
-			print_block(stderr, 0, p_s_bh, 3, -1, -1);
+			print_block(stderr, NULL, p_s_bh, 3, -1, -1);
 			reiserfs_panic("search_by_key: expected level %d",
 				       expected_level);
 		}
diff --git a/resize_reiserfs/resize_reiserfs.c b/resize_reiserfs/resize_reiserfs.c
index 58ba49c..09a5b10 100644
--- a/resize_reiserfs/resize_reiserfs.c
+++ b/resize_reiserfs/resize_reiserfs.c
@@ -249,7 +249,7 @@ int main(int argc, char *argv[])
 
 	devname = argv[optind];
 
-	fs = reiserfs_open(devname, O_RDONLY, &error, 0, 1);
+	fs = reiserfs_open(devname, O_RDONLY, &error, NULL, 1);
 	if (!fs) {
 		if (error) {
 			reiserfs_exit(1, "cannot open '%s': %s",
@@ -319,7 +319,7 @@ int main(int argc, char *argv[])
 		reiserfs_exit(1, "the file system isn't in valid state.");
 
 	/* Needed to keep idiot compiler from issuing false warning */
-	sb_old = 0;
+	sb_old = NULL;
 
 	/* save SB for reporting */
 	if (opt_verbose) {
diff --git a/tune/tune.c b/tune/tune.c
index a22cbc0..7a9b0e7 100644
--- a/tune/tune.c
+++ b/tune/tune.c
@@ -409,36 +409,36 @@ int main(int argc, char **argv)
 	if (argc < 2)
 		print_usage_and_exit();
 
-	device_name = 0;
-	jdevice_name = 0;
-	j_new_device_name = 0;
+	device_name = NULL;
+	jdevice_name = NULL;
+	j_new_device_name = NULL;
 
 	memset(UUID, 0, 16);
 
 	while (1) {
 		static struct option options[] = {
-			{"help", no_argument, 0, 'h'},
-			{"journal-device", required_argument, 0, 'j'},
+			{"help", no_argument, NULL, 'h'},
+			{"journal-device", required_argument, NULL, 'j'},
 			{"journal-new-device", required_argument, &flag,
 			 OPT_NEW_J},
-			{"journal-new-size", required_argument, 0, 's'},
-			{"trans-max-size", required_argument, 0, 't'},
-			{"journal-new-offset", required_argument, 0, 'o'},
+			{"journal-new-size", required_argument, NULL, 's'},
+			{"trans-max-size", required_argument, NULL, 't'},
+			{"journal-new-offset", required_argument, NULL, 'o'},
 			{"no-journal-available", no_argument, &flag,
 			 OPT_SKIP_J},
-			/*{"keep-old-journal-param", no_argument, 0, 'p'}, */
-			{"uuid", required_argument, 0, 'u'},
-			{"label", required_argument, 0, 'l'},
-			{"add-badblocks", required_argument, 0, 'b'},
-			{"badblocks", required_argument, 0, 'B'},
-			{"force", no_argument, 0, 'f'},
+			/*{"keep-old-journal-param", no_argument, NULL, 'p'}, */
+			{"uuid", required_argument, NULL, 'u'},
+			{"label", required_argument, NULL, 'l'},
+			{"add-badblocks", required_argument, NULL, 'b'},
+			{"badblocks", required_argument, NULL, 'B'},
+			{"force", no_argument, NULL, 'f'},
 			{"make-journal-standard", no_argument, &flag,
 			 OPT_STANDARD},
-			{"check-interval", required_argument, 0, 'c'},
-			{"time-last-checked", required_argument, 0, 'C'},
-			{"max-mount-count", required_argument, 0, 'm'},
-			{"mount-count", required_argument, 0, 'M'},
-			{0, 0, 0, 0}
+			{"check-interval", required_argument, NULL, 'c'},
+			{"time-last-checked", required_argument, NULL, 'C'},
+			{"max-mount-count", required_argument, NULL, 'm'},
+			{"mount-count", required_argument, NULL, 'M'},
+			{}
 		};
 		int option_index;
 
@@ -560,7 +560,7 @@ int main(int argc, char **argv)
 	/* device to be formatted */
 	device_name = argv[optind];
 
-	fs = reiserfs_open(device_name, O_RDONLY, 0, NULL, 1);
+	fs = reiserfs_open(device_name, O_RDONLY, NULL, NULL, 1);
 	if (no_reiserfs_found(fs)) {
 		message("Cannot open reiserfs on %s", device_name);
 		return 1;