bcachefs: Improved backpointer messages in fsck

When we have a key to print, we should print it.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

diff --git a/fs/bcachefs/fsck.c b/fs/bcachefs/fsck.c
index e0c5cd119acc938a5bfe3ff2be8cac2cf1504b11..f7bcde976f9245fb69f103b210c4fbe2dc3f222f 100644 (file)
--- a/fs/bcachefs/fsck.c
+++ b/fs/bcachefs/fsck.c
@@ -1023,25 +1023,6 @@ static bool dirent_points_to_inode(struct bkey_s_c_dirent d,
                : le64_to_cpu(d.v->d_inum)              == inode->bi_inum;
 }
 
-static int inode_backpointer_exists(struct btree_trans *trans,
-                                   struct bch_inode_unpacked *inode,
-                                   u32 snapshot)
-{
-       struct btree_iter iter;
-       struct bkey_s_c_dirent d;
-       int ret;
-
-       d = dirent_get_by_pos(trans, &iter,
-                       SPOS(inode->bi_dir, inode->bi_dir_offset, snapshot));
-       ret = bkey_err(d);
-       if (ret)
-               return bch2_err_matches(ret, ENOENT) ? 0 : ret;
-
-       ret = dirent_points_to_inode(d, inode);
-       bch2_trans_iter_exit(trans, &iter);
-       return ret;
-}
-
 static int check_i_sectors(struct btree_trans *trans, struct inode_walker *w)
 {
        struct bch_fs *c = trans->c;
@@ -1553,8 +1534,8 @@ static int check_dirent_target(struct btree_trans *trans,
 {
        struct bch_fs *c = trans->c;
        struct bkey_i_dirent *n;
-       bool backpointer_exists = true;
        struct printbuf buf = PRINTBUF;
+       struct btree_iter bp_iter = { NULL };
        int ret = 0;
 
        if (!target->bi_dir &&
@@ -1568,25 +1549,37 @@ static int check_dirent_target(struct btree_trans *trans,
        }
 
        if (!inode_points_to_dirent(target, d)) {
-               ret = inode_backpointer_exists(trans, target, d.k->p.snapshot);
-               if (ret < 0)
+               struct bkey_s_c_dirent bp_dirent = dirent_get_by_pos(trans, &bp_iter,
+                                     SPOS(target->bi_dir, target->bi_dir_offset, target_snapshot));
+               ret = bkey_err(bp_dirent);
+               if (ret && !bch2_err_matches(ret, ENOENT))
                        goto err;
 
-               backpointer_exists = ret;
+               bool backpointer_exists = !ret;
                ret = 0;
 
+               bch2_bkey_val_to_text(&buf, c, d.s_c);
+               prt_newline(&buf);
+               if (backpointer_exists)
+                       bch2_bkey_val_to_text(&buf, c, bp_dirent.s_c);
+
                if (fsck_err_on(S_ISDIR(target->bi_mode) && backpointer_exists,
                                c, inode_dir_multiple_links,
-                               "directory %llu with multiple links",
-                               target->bi_inum)) {
+                               "directory %llu:%u with multiple links\n%s",
+                               target->bi_inum, target_snapshot, buf.buf)) {
                        ret = __remove_dirent(trans, d.k->p);
                        goto out;
                }
 
+               /*
+                * hardlinked file with nlink 0:
+                * We're just adjusting nlink here so check_nlinks() will pick
+                * it up, it ignores inodes with nlink 0
+                */
                if (fsck_err_on(backpointer_exists && !target->bi_nlink,
                                c, inode_multiple_links_but_nlink_0,
-                               "inode %llu type %s has multiple links but i_nlink 0",
-                               target->bi_inum, bch2_d_types[d.v->d_type])) {
+                               "inode %llu:%u type %s has multiple links but i_nlink 0\n%s",
+                               target->bi_inum, target_snapshot, bch2_d_types[d.v->d_type], buf.buf)) {
                        target->bi_nlink++;
                        target->bi_flags &= ~BCH_INODE_unlinked;
 
@@ -1660,6 +1653,7 @@ static int check_dirent_target(struct btree_trans *trans,
 out:
 err:
 fsck_err:
+       bch2_trans_iter_exit(trans, &bp_iter);
        printbuf_exit(&buf);
        bch_err_fn(c, ret);
        return ret;
@@ -2401,7 +2395,7 @@ static int check_nlinks_update_hardlinks(struct bch_fs *c,
                                NULL, NULL, BTREE_INSERT_LAZY_RW|BTREE_INSERT_NOFAIL,
                        check_nlinks_update_inode(trans, &iter, k, links, &idx, range_end)));
        if (ret < 0) {
-               bch_err(c, "error in fsck: btree error %i while walking inodes", ret);
+               bch_err(c, "error in fsck walking inodes: %s", bch2_err_str(ret));
                return ret;
        }