btrfs-progs: check: add helpers for converting between structures

We either open code list_entry calls or outright cast between types.  The
compiler will do the right thing if we use static inlines to do
typesafe conversions.

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

diff --git a/cmds-check.c b/cmds-check.c
index 9927fce..4318f4f 100644 (file)
--- a/cmds-check.c
+++ b/cmds-check.c
@@ -84,6 +84,11 @@ struct extent_backref {
        unsigned int broken:1;
 };
 
+static inline struct extent_backref* to_extent_backref(struct list_head *entry)
+{
+       return list_entry(entry, struct extent_backref, list);
+}
+
 struct data_backref {
        struct extent_backref node;
        union {
@@ -99,6 +104,11 @@ struct data_backref {
        u32 found_ref;
 };
 
+static inline struct data_backref* to_data_backref(struct extent_backref *back)
+{
+       return container_of(back, struct data_backref, node);
+}
+
 /*
  * Much like data_backref, just removed the undetermined members
  * and change it to use list_head.
@@ -122,6 +132,11 @@ struct tree_backref {
        };
 };
 
+static inline struct tree_backref* to_tree_backref(struct extent_backref *back)
+{
+       return container_of(back, struct tree_backref, node);
+}
+
 /* Explicit initialization for extent_record::flag_block_full_backref */
 enum { FLAG_UNSET = 2 };
 
@@ -152,6 +167,11 @@ struct extent_record {
        unsigned int wrong_chunk_type:1;
 };
 
+static inline struct extent_record* to_extent_record(struct list_head *entry)
+{
+       return container_of(entry, struct extent_record, list);
+}
+
 struct inode_backref {
        struct list_head list;
        unsigned int found_dir_item:1;
@@ -166,6 +186,11 @@ struct inode_backref {
        char name[0];
 };
 
+static inline struct inode_backref* to_inode_backref(struct list_head *entry)
+{
+       return list_entry(entry, struct inode_backref, list);
+}
+
 struct root_item_record {
        struct list_head list;
        u64 objectid;
@@ -256,6 +281,11 @@ struct root_backref {
        char name[0];
 };
 
+static inline struct root_backref* to_root_backref(struct list_head *entry)
+{
+       return list_entry(entry, struct root_backref, list);
+}
+
 struct root_record {
        struct list_head backrefs;
        struct cache_extent cache;
@@ -834,8 +864,7 @@ static void free_inode_rec(struct inode_record *rec)
                return;
 
        while (!list_empty(&rec->backrefs)) {
-               backref = list_entry(rec->backrefs.next,
-                                    struct inode_backref, list);
+               backref = to_inode_backref(rec->backrefs.next);
                list_del(&backref->list);
                free(backref);
        }
@@ -1979,7 +2008,7 @@ static int check_root_dir(struct inode_record *rec)
                goto out;
        if (list_empty(&rec->backrefs))
                goto out;
-       backref = list_entry(rec->backrefs.next, struct inode_backref, list);
+       backref = to_inode_backref(rec->backrefs.next);
        if (!backref->found_inode_ref)
                goto out;
        if (backref->index != 0 || backref->namelen != 2 ||
@@ -3116,8 +3145,7 @@ static void free_root_record(struct cache_extent *cache)
 
        rec = container_of(cache, struct root_record, cache);
        while (!list_empty(&rec->backrefs)) {
-               backref = list_entry(rec->backrefs.next,
-                                    struct root_backref, list);
+               backref = to_root_backref(rec->backrefs.next);
                list_del(&backref->list);
                free(backref);
        }
@@ -3751,14 +3779,14 @@ static int all_backpointers_checked(struct extent_record *rec, int print_errs)
        int err = 0;
 
        while(cur != &rec->backrefs) {
-               back = list_entry(cur, struct extent_backref, list);
+               back = to_extent_backref(cur);
                cur = cur->next;
                if (!back->found_extent_tree) {
                        err = 1;
                        if (!print_errs)
                                goto out;
                        if (back->is_data) {
-                               dback = (struct data_backref *)back;
+                               dback = to_data_backref(back);
                                fprintf(stderr, "Backref %llu %s %llu"
                                        " owner %llu offset %llu num_refs %lu"
                                        " not found in extent tree\n",
@@ -3772,7 +3800,7 @@ static int all_backpointers_checked(struct extent_record *rec, int print_errs)
                                        (unsigned long long)dback->offset,
                                        (unsigned long)dback->num_refs);
                        } else {
-                               tback = (struct tree_backref *)back;
+                               tback = to_tree_backref(back);
                                fprintf(stderr, "Backref %llu parent %llu"
                                        " root %llu not found in extent tree\n",
                                        (unsigned long long)rec->start,
@@ -3784,7 +3812,7 @@ static int all_backpointers_checked(struct extent_record *rec, int print_errs)
                        err = 1;
                        if (!print_errs)
                                goto out;
-                       tback = (struct tree_backref *)back;
+                       tback = to_tree_backref(back);
                        fprintf(stderr, "Backref %llu %s %llu not referenced back %p\n",
                                (unsigned long long)rec->start,
                                back->full_backref ? "parent" : "root",
@@ -3793,7 +3821,7 @@ static int all_backpointers_checked(struct extent_record *rec, int print_errs)
                                (unsigned long long)tback->root, back);
                }
                if (back->is_data) {
-                       dback = (struct data_backref *)back;
+                       dback = to_data_backref(back);
                        if (dback->found_ref != dback->num_refs) {
                                err = 1;
                                if (!print_errs)
@@ -3837,7 +3865,7 @@ static int all_backpointers_checked(struct extent_record *rec, int print_errs)
                if (!back->is_data) {
                        found += 1;
                } else {
-                       dback = (struct data_backref *)back;
+                       dback = to_data_backref(back);
                        found += dback->found_ref;
                }
        }
@@ -3861,7 +3889,7 @@ static int free_all_extent_backrefs(struct extent_record *rec)
        struct list_head *cur;
        while (!list_empty(&rec->backrefs)) {
                cur = rec->backrefs.next;
-               back = list_entry(cur, struct extent_backref, list);
+               back = to_extent_backref(cur);
                list_del(cur);
                free(back);
        }
@@ -3922,7 +3950,7 @@ static int check_owner_ref(struct btrfs_root *root,
                        continue;
                if (node->full_backref)
                        continue;
-               back = (struct tree_backref *)node;
+               back = to_tree_backref(node);
                if (btrfs_header_owner(buf) == back->root)
                        return 0;
        }
@@ -3966,11 +3994,11 @@ static int is_extent_tree_record(struct extent_record *rec)
        int is_extent = 0;
 
        while(cur != &rec->backrefs) {
-               node = list_entry(cur, struct extent_backref, list);
+               node = to_extent_backref(cur);
                cur = cur->next;
                if (node->is_data)
                        return 0;
-               back = (struct tree_backref *)node;
+               back = to_tree_backref(node);
                if (node->full_backref)
                        return 0;
                if (back->root == BTRFS_EXTENT_TREE_OBJECTID)
@@ -4353,11 +4381,11 @@ static struct tree_backref *find_tree_backref(struct extent_record *rec,
        struct tree_backref *back;
 
        while(cur != &rec->backrefs) {
-               node = list_entry(cur, struct extent_backref, list);
+               node = to_extent_backref(cur);
                cur = cur->next;
                if (node->is_data)
                        continue;
-               back = (struct tree_backref *)node;
+               back = to_tree_backref(node);
                if (parent > 0) {
                        if (!node->full_backref)
                                continue;
@@ -4404,11 +4432,11 @@ static struct data_backref *find_data_backref(struct extent_record *rec,
        struct data_backref *back;
 
        while(cur != &rec->backrefs) {
-               node = list_entry(cur, struct extent_backref, list);
+               node = to_extent_backref(cur);
                cur = cur->next;
                if (!node->is_data)
                        continue;
-               back = (struct data_backref *)node;
+               back = to_data_backref(node);
                if (parent > 0) {
                        if (!node->full_backref)
                                continue;
@@ -4494,8 +4522,7 @@ static void check_extent_type(struct extent_record *rec)
                struct tree_backref *tback;
                u64 bg_type;
 
-               node = list_entry(rec->backrefs.next, struct extent_backref,
-                                 list);
+               node = to_extent_backref(rec->backrefs.next);
                if (node->is_data) {
                        /* tree block shouldn't have data backref */
                        rec->wrong_chunk_type = 1;
@@ -6507,7 +6534,7 @@ static int record_extent(struct btrfs_trans_handle *trans,
                } else {
                        struct btrfs_disk_key copy_key;;
 
-                       tback = (struct tree_backref *)back;
+                       tback = to_tree_backref(back);
                        bi = (struct btrfs_tree_block_info *)(ei + 1);
                        memset_extent_buffer(leaf, 0, (unsigned long)bi,
                                             sizeof(*bi));
@@ -6536,7 +6563,7 @@ static int record_extent(struct btrfs_trans_handle *trans,
                u64 parent;
                int i;
 
-               dback = (struct data_backref *)back;
+               dback = to_data_backref(back);
                if (back->full_backref)
                        parent = dback->parent;
                else
@@ -6574,7 +6601,7 @@ static int record_extent(struct btrfs_trans_handle *trans,
        } else {
                u64 parent;
 
-               tback = (struct tree_backref *)back;
+               tback = to_tree_backref(back);
                if (back->full_backref)
                        parent = tback->parent;
                else
@@ -6823,7 +6850,7 @@ static int verify_backrefs(struct btrfs_fs_info *info, struct btrfs_path *path,
                if (back->full_backref || !back->is_data)
                        continue;
 
-               dback = (struct data_backref *)back;
+               dback = to_data_backref(back);
 
                /*
                 * We only pay attention to backrefs that we found a real
@@ -6949,7 +6976,7 @@ static int verify_backrefs(struct btrfs_fs_info *info, struct btrfs_path *path,
                if (back->full_backref || !back->is_data)
                        continue;
 
-               dback = (struct data_backref *)back;
+               dback = to_data_backref(back);
 
                /*
                 * Still ignoring backrefs that don't have a real ref attached
@@ -7013,7 +7040,7 @@ static int process_duplicates(struct btrfs_root *root,
         */
        remove_cache_extent(extent_cache, &rec->cache);
 
-       good = list_entry(rec->dups.next, struct extent_record, list);
+       good = to_extent_record(rec->dups.next);
        list_del_init(&good->list);
        INIT_LIST_HEAD(&good->backrefs);
        INIT_LIST_HEAD(&good->dups);
@@ -7147,7 +7174,7 @@ static int delete_duplicate_records(struct btrfs_root *root,
                ret = err;
 out:
        while (!list_empty(&delete_list)) {
-               tmp = list_entry(delete_list.next, struct extent_record, list);
+               tmp = to_extent_record(delete_list.next);
                list_del_init(&tmp->list);
                if (tmp == rec)
                        continue;
@@ -7155,7 +7182,7 @@ out:
        }
 
        while (!list_empty(&rec->dups)) {
-               tmp = list_entry(rec->dups.next, struct extent_record, list);
+               tmp = to_extent_record(rec->dups.next);
                list_del_init(&tmp->list);
                free(tmp);
        }
@@ -7187,7 +7214,7 @@ static int find_possible_backrefs(struct btrfs_fs_info *info,
                if (back->full_backref || !back->is_data)
                        continue;
 
-               dback = (struct data_backref *)back;
+               dback = to_data_backref(back);
 
                /* We found this one, we don't need to do a lookup */
                if (dback->found_ref)
@@ -7286,7 +7313,7 @@ static int record_orphan_data_extents(struct btrfs_fs_info *fs_info,
                if (back->full_backref || !back->is_data ||
                    !back->found_extent_tree)
                        continue;
-               dback = (struct data_backref *)back;
+               dback = to_data_backref(back);
                if (dback->found_ref)
                        continue;
                key.objectid = dback->root;
@@ -7403,7 +7430,7 @@ static int fixup_extent_refs(struct btrfs_fs_info *info,
 
        /* step three, recreate all the refs we did find */
        while(cur != &rec->backrefs) {
-               back = list_entry(cur, struct extent_backref, list);
+               back = to_extent_backref(cur);
                cur = cur->next;
 
                /*
@@ -7660,8 +7687,7 @@ static int check_extent_refs(struct btrfs_root *root,
         * belong to a different extent item and not the weird duplicate one.
         */
        while (repair && !list_empty(&duplicate_extents)) {
-               rec = list_entry(duplicate_extents.next, struct extent_record,
-                                list);
+               rec = to_extent_record(duplicate_extents.next);
                list_del_init(&rec->list);
 
                /* Sometimes we can find a backref before we find an actual