yaffs: Sort out issues raised by Coverity

Coverity checks raised some issues, particularly with NULL checks.

Fix them.

Signed-off-by: Charles Manning <cdhmanning@gmail.com>

7 files changed, 98 insertions, 107 deletions

diff --git a/yaffs_guts.c b/yaffs_guts.c
index f4ae9de..486b7e0 100644
--- a/yaffs_guts.c
+++ b/yaffs_guts.c
@@ -1532,7 +1532,7 @@ static struct yaffs_cache *yaffs_grab_chunk_cache(struct yaffs_dev *dev)
 
 			/* With locking we can't assume we can use entry zero */
 
-			the_obj = NULL;
+			the_obj = dev->cache[0].object;
 			usage = -1;
 			cache = NULL;
 			pushout = -1;
@@ -1952,16 +1952,12 @@ struct yaffs_obj *yaffs_find_by_number(struct yaffs_dev *dev, u32 number)
 
 	list_for_each(i, &dev->obj_bucket[bucket].list) {
 		/* Look if it is in the list */
-		if (i) {
-			in = list_entry(i, struct yaffs_obj, hash_link);
-			if (in->obj_id == number) {
-
-				/* Don't tell the VFS about this one if it is defered free */
-				if (in->defered_free)
-					return NULL;
-
-				return in;
-			}
+		in = list_entry(i, struct yaffs_obj, hash_link);
+		if (in->obj_id == number) {
+			/* Don't tell the VFS about this one if it is defered free */
+			if (in->defered_free)
+				return NULL;
+			return in;
 		}
 	}
 
@@ -4082,11 +4078,13 @@ static int yaffs_unlink_worker(struct yaffs_obj *obj)
 
 	int del_now = 0;
 
+	if(!obj)
+	        return YAFFS_FAIL;
+
 	if (!obj->my_inode)
 		del_now = 1;
 
-	if (obj)
-		yaffs_update_parent(obj->parent);
+	yaffs_update_parent(obj->parent);
 
 	if (obj->variant_type == YAFFS_OBJECT_TYPE_HARDLINK) {
 		return yaffs_del_link(obj);
@@ -4496,29 +4494,26 @@ struct yaffs_obj *yaffs_find_by_name(struct yaffs_obj *directory,
 	sum = yaffs_calc_name_sum(name);
 
 	list_for_each(i, &directory->variant.dir_variant.children) {
-		if (i) {
-			l = list_entry(i, struct yaffs_obj, siblings);
+		l = list_entry(i, struct yaffs_obj, siblings);
 
-			if (l->parent != directory)
-				YBUG();
+		if (l->parent != directory)
+			YBUG();
 
-			yaffs_check_obj_details_loaded(l);
+		yaffs_check_obj_details_loaded(l);
 
-			/* Special case for lost-n-found */
-			if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
-				if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
-					return l;
-			} else if (l->sum == sum
-				   || l->hdr_chunk <= 0) {
-				/* LostnFound chunk called Objxxx
-				 * Do a real check
-				 */
-				yaffs_get_obj_name(l, buffer,
-						   YAFFS_MAX_NAME_LENGTH + 1);
-				if (strncmp
-				    (name, buffer, YAFFS_MAX_NAME_LENGTH) == 0)
-					return l;
-			}
+		/* Special case for lost-n-found */
+		if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
+			if (!strcmp(name, YAFFS_LOSTNFOUND_NAME))
+				return l;
+		} else if (l->sum == sum
+			   || l->hdr_chunk <= 0) {
+			/* LostnFound chunk called Objxxx
+			 * Do a real check
+			 */
+			yaffs_get_obj_name(l, buffer,
+				YAFFS_MAX_NAME_LENGTH + 1);
+			if (strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH) == 0)
+				return l;
 		}
 	}
 
diff --git a/yaffs_nand.c b/yaffs_nand.c
index e816cab..f7810d0 100644
--- a/yaffs_nand.c
+++ b/yaffs_nand.c
@@ -72,6 +72,7 @@ int yaffs_wr_chunk_tags_nand(struct yaffs_dev *dev,
 	} else {
 		yaffs_trace(YAFFS_TRACE_ERROR, "Writing with no tags");
 		YBUG();
+		return FALSE;
 	}
 
 	if (dev->param.write_chunk_tags_fn)
diff --git a/yaffs_tagscompat.c b/yaffs_tagscompat.c
index 7578075..818f72b 100644
--- a/yaffs_tagscompat.c
+++ b/yaffs_tagscompat.c
@@ -151,7 +151,7 @@ static int yaffs_rd_chunk_nand(struct yaffs_dev *dev,
 	int ret_val;
 	struct yaffs_spare local_spare;
 
-	if (!spare && data) {
+	if (!spare) {
 		/* If we don't have a real spare, then we use a local one. */
 		/* Need this for the calculation of the ecc */
 		spare = &local_spare;
@@ -290,7 +290,7 @@ int yaffs_tags_compat_wr(struct yaffs_dev *dev,
 	struct yaffs_tags tags;
 
 	yaffs_spare_init(&spare);
-
+        
 	if (ext_tags->is_deleted)
 		spare.page_status = 0;
 	else {
diff --git a/yaffs_verify.c b/yaffs_verify.c
index 738c7f6..55884b9 100644
--- a/yaffs_verify.c
+++ b/yaffs_verify.c
@@ -163,8 +163,8 @@ void yaffs_verify_blocks(struct yaffs_dev *dev)
 }
 
 /*
- * Verify the object header. oh must be valid, but obj and tags may be NULL in which
- * case those tests will not be performed.
+ * Verify the object header. oh must be valid, but obj and tags may be NULL in
+ * which case those tests will not be performed.
  */
 void yaffs_verify_oh(struct yaffs_obj *obj, struct yaffs_obj_hdr *oh,
 		     struct yaffs_ext_tags *tags, int parent_check)
@@ -414,11 +414,8 @@ void yaffs_verify_objects(struct yaffs_dev *dev)
 
 	for (i = 0; i < YAFFS_NOBJECT_BUCKETS; i++) {
 		list_for_each(lh, &dev->obj_bucket[i].list) {
-			if (lh) {
-				obj =
-				    list_entry(lh, struct yaffs_obj, hash_link);
-				yaffs_verify_obj(obj);
-			}
+			obj = list_entry(lh, struct yaffs_obj, hash_link);	
+			yaffs_verify_obj(obj);
 		}
 	}
 }
@@ -453,12 +450,10 @@ void yaffs_verify_obj_in_dir(struct yaffs_obj *obj)
 	/* Iterate through the objects in each hash entry */
 
 	list_for_each(lh, &obj->parent->variant.dir_variant.children) {
-		if (lh) {
-			list_obj = list_entry(lh, struct yaffs_obj, siblings);
-			yaffs_verify_obj(list_obj);
-			if (obj == list_obj)
-				count++;
-		}
+		list_obj = list_entry(lh, struct yaffs_obj, siblings);
+		yaffs_verify_obj(list_obj);
+		if (obj == list_obj)
+			count++;
 	}
 
 	if (count != 1) {
@@ -492,16 +487,14 @@ void yaffs_verify_dir(struct yaffs_obj *directory)
 	/* Iterate through the objects in each hash entry */
 
 	list_for_each(lh, &directory->variant.dir_variant.children) {
-		if (lh) {
-			list_obj = list_entry(lh, struct yaffs_obj, siblings);
-			if (list_obj->parent != directory) {
-				yaffs_trace(YAFFS_TRACE_ALWAYS,
-					"Object in directory list has wrong parent %p",
-					list_obj->parent);
-				YBUG();
-			}
-			yaffs_verify_obj_in_dir(list_obj);
+		list_obj = list_entry(lh, struct yaffs_obj, siblings);
+		if (list_obj->parent != directory) {
+			yaffs_trace(YAFFS_TRACE_ALWAYS,
+				"Object in directory list has wrong parent %p",
+				list_obj->parent);
+			YBUG();
 		}
+		yaffs_verify_obj_in_dir(list_obj);
 	}
 }
 
diff --git a/yaffs_vfs_multi.c b/yaffs_vfs_multi.c
index 9feecdf..78e2f9f 100644
--- a/yaffs_vfs_multi.c
+++ b/yaffs_vfs_multi.c
@@ -692,11 +692,9 @@ static void yaffs_remove_obj_callback(struct yaffs_obj *obj)
 	 * the search context to the next object to prevent a hanging pointer.
 	 */
 	list_for_each(i, search_contexts) {
-		if (i) {
-			sc = list_entry(i, struct yaffs_search_context, others);
-			if (sc->next_return == obj)
-				yaffs_search_advance(sc);
-		}
+		sc = list_entry(i, struct yaffs_search_context, others);
+		if (sc->next_return == obj)
+			yaffs_search_advance(sc);
 	}
 
 }
@@ -1421,6 +1419,12 @@ static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
 
 	obj = yaffs_dentry_to_obj(f->f_dentry);
 
+	if (!obj) {
+		yaffs_trace(YAFFS_TRACE_OS,
+			"yaffs_file_write: hey obj is null!");
+                return -EINVAL;
+        }
+
 	dev = obj->my_dev;
 
 	yaffs_gross_lock(dev);
@@ -1432,13 +1436,9 @@ static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
 	else
 		ipos = *pos;
 
-	if (!obj)
-		yaffs_trace(YAFFS_TRACE_OS,
-			"yaffs_file_write: hey obj is null!");
-	else
-		yaffs_trace(YAFFS_TRACE_OS,
-			"yaffs_file_write about to write writing %u(%x) bytes to object %d at %d(%x)",
-			(unsigned)n, (unsigned)n, obj->obj_id, ipos, ipos);
+	yaffs_trace(YAFFS_TRACE_OS,
+		"yaffs_file_write about to write writing %u(%x) bytes to object %d at %d(%x)",
+		(unsigned)n, (unsigned)n, obj->obj_id, ipos, ipos);
 
 	n_written = yaffs_wr_file(obj, buf, ipos, n, 0);
 
@@ -2623,6 +2623,11 @@ static struct super_block *yaffs_internal_read_super(int yaffs_version,
 	struct yaffs_linux_context *context_iterator;
 	struct list_head *l;
 
+	if (!sb) {
+		printk(KERN_INFO "yaffs: sb is NULL\n");
+		return NULL;
+        }
+
 	sb->s_magic = YAFFS_MAGIC;
 	sb->s_op = &yaffs_super_ops;
 	sb->s_flags |= MS_NOATIME;
@@ -2633,9 +2638,7 @@ static struct super_block *yaffs_internal_read_super(int yaffs_version,
 	sb->s_export_op = &yaffs_export_ops;
 #endif
 
-	if (!sb)
-		printk(KERN_INFO "yaffs: sb is NULL\n");
-	else if (!sb->s_dev)
+	if (!sb->s_dev)
 		printk(KERN_INFO "yaffs: sb->s_dev is NULL\n");
 	else if (!yaffs_devname(sb, devname_buf))
 		printk(KERN_INFO "yaffs: devname is NULL\n");
diff --git a/yaffs_vfs_single.c b/yaffs_vfs_single.c
index 2cd6047..1893125 100644
--- a/yaffs_vfs_single.c
+++ b/yaffs_vfs_single.c
@@ -783,11 +783,9 @@ static void yaffs_remove_obj_callback(struct yaffs_obj *obj)
 	 * the search context to the next object to prevent a hanging pointer.
 	 */
 	list_for_each(i, search_contexts) {
-		if (i) {
-			sc = list_entry(i, struct yaffs_search_context, others);
-			if (sc->next_return == obj)
-				yaffs_search_advance(sc);
-		}
+		sc = list_entry(i, struct yaffs_search_context, others);
+		if (sc->next_return == obj)
+			yaffs_search_advance(sc);
 	}
 
 }
@@ -1376,6 +1374,13 @@ static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
 
 	obj = yaffs_dentry_to_obj(f->f_dentry);
 
+	if (!obj) {
+	        /* This should not happen */
+		yaffs_trace(YAFFS_TRACE_OS,
+			"yaffs_file_write: hey obj is null!");
+                return -ENINVAL;
+        }
+
 	dev = obj->my_dev;
 
 	yaffs_gross_lock(dev);
@@ -1387,13 +1392,9 @@ static ssize_t yaffs_file_write(struct file *f, const char *buf, size_t n,
 	else
 		ipos = *pos;
 
-	if (!obj)
-		yaffs_trace(YAFFS_TRACE_OS,
-			"yaffs_file_write: hey obj is null!");
-	else
-		yaffs_trace(YAFFS_TRACE_OS,
-			"yaffs_file_write about to write writing %u(%x) bytes to object %d at %d(%x)",
-			(unsigned)n, (unsigned)n, obj->obj_id, ipos, ipos);
+	yaffs_trace(YAFFS_TRACE_OS,
+		"yaffs_file_write about to write writing %u(%x) bytes to object %d at %d(%x)",
+		(unsigned)n, (unsigned)n, obj->obj_id, ipos, ipos);
 
 	n_written = yaffs_wr_file(obj, buf, ipos, n, 0);
 
@@ -2027,6 +2028,11 @@ static struct super_block *yaffs_internal_read_super(int yaffs_version,
 	struct yaffs_linux_context *context_iterator;
 	struct list_head *l;
 
+	if (!sb) {
+		printk(KERN_INFO "yaffs: sb is NULL\n");
+		return NULL;
+        }
+
 	sb->s_magic = YAFFS_MAGIC;
 	sb->s_op = &yaffs_super_ops;
 	sb->s_flags |= MS_NOATIME;
@@ -2035,9 +2041,7 @@ static struct super_block *yaffs_internal_read_super(int yaffs_version,
 
 	sb->s_export_op = &yaffs_export_ops;
 
-	if (!sb)
-		printk(KERN_INFO "yaffs: sb is NULL\n");
-	else if (!sb->s_dev)
+	if (!sb->s_dev)
 		printk(KERN_INFO "yaffs: sb->s_dev is NULL\n");
 	else if (!yaffs_devname(sb, devname_buf))
 		printk(KERN_INFO "yaffs: devname is NULL\n");
diff --git a/yaffs_yaffs2.c b/yaffs_yaffs2.c
index 33397af..339f47f 100644
--- a/yaffs_yaffs2.c
+++ b/yaffs_yaffs2.c
@@ -568,28 +568,23 @@ static int yaffs2_wr_checkpt_objs(struct yaffs_dev *dev)
 
 	for (i = 0; ok && i < YAFFS_NOBJECT_BUCKETS; i++) {
 		list_for_each(lh, &dev->obj_bucket[i].list) {
-			if (lh) {
-				obj =
-				    list_entry(lh, struct yaffs_obj, hash_link);
-				if (!obj->defered_free) {
-					yaffs2_obj_checkpt_obj(&cp, obj);
-					cp.struct_type = sizeof(cp);
-
-					yaffs_trace(YAFFS_TRACE_CHECKPOINT,
-						"Checkpoint write object %d parent %d type %d chunk %d obj addr %p",
-						cp.obj_id, cp.parent_id,
-						cp.variant_type, cp.hdr_chunk, obj);
-
-					ok = (yaffs2_checkpt_wr
-					      (dev, &cp,
+			obj = list_entry(lh, struct yaffs_obj, hash_link);
+                        if (!obj->defered_free) {
+				yaffs2_obj_checkpt_obj(&cp, obj);
+				cp.struct_type = sizeof(cp);
+
+				yaffs_trace(YAFFS_TRACE_CHECKPOINT,
+					"Checkpoint write object %d parent %d type %d chunk %d obj addr %p",
+					cp.obj_id, cp.parent_id,
+					cp.variant_type, cp.hdr_chunk, obj);
+
+				ok = (yaffs2_checkpt_wr(dev, &cp,
 					       sizeof(cp)) == sizeof(cp));
 
-					if (ok
-					    && obj->variant_type ==
-					    YAFFS_OBJECT_TYPE_FILE)
-						ok = yaffs2_wr_checkpt_tnodes
-						    (obj);
-				}
+				if (ok &&
+				        obj->variant_type ==
+				                YAFFS_OBJECT_TYPE_FILE)
+                                        ok = yaffs2_wr_checkpt_tnodes(obj);
 			}
 		}
 	}