[PATCH 3/3] bcachefs: Move the link counting check to the VFS layer

[Youling Tang]

From: Youling Tang <tangyoul...@kylinos.cn>

Currently bcachefs only performs link count checks during link operations,
during rename and mkdir operations, the link count should also be checked.

This patch moves the checks to the vfs_{link,rename,mkdir} functions when
sb->s_max_links is set, eliminating the need for filesystem-specific checks.

Signed-off-by: Youling Tang <tangyoul...@kylinos.cn>
---
 fs/bcachefs/errcode.h |  1 -
 fs/bcachefs/fs.c      |  1 +
 fs/bcachefs/inode.c   | 10 ++--------
 fs/bcachefs/inode.h   |  2 +-
 fs/bcachefs/namei.c   |  4 +---
 5 files changed, 5 insertions(+), 13 deletions(-)

diff --git a/fs/bcachefs/errcode.h b/fs/bcachefs/errcode.h
index b22a694ec750..acc3b7b67704 100644
--- a/fs/bcachefs/errcode.h
+++ b/fs/bcachefs/errcode.h
@@ -215,7 +215,6 @@
        x(EINVAL,                       varint_decode_error)                    
\
        x(EINVAL,                       erasure_coding_found_btree_node)        
\
        x(EINVAL,                       option_negative)                        
\
-       x(EMLINK,                       too_many_links)                         
\
        x(EOPNOTSUPP,                   may_not_use_incompat_feature)           
\
        x(EROFS,                        erofs_trans_commit)                     
\
        x(EROFS,                        erofs_no_writes)                        
\
diff --git a/fs/bcachefs/fs.c b/fs/bcachefs/fs.c
index 687af0eea0c2..6b60c97c5610 100644
--- a/fs/bcachefs/fs.c
+++ b/fs/bcachefs/fs.c
@@ -2526,6 +2526,7 @@ static int bch2_fs_get_tree(struct fs_context *fc)
        sb->s_time_gran         = c->sb.nsec_per_time_unit;
        sb->s_time_min          = div_s64(S64_MIN, c->sb.time_units_per_sec) + 
1;
        sb->s_time_max          = div_s64(S64_MAX, c->sb.time_units_per_sec);
+       sb->s_max_links         = BCH_LINK_MAX;
        super_set_uuid(sb, c->sb.user_uuid.b, sizeof(c->sb.user_uuid));
 
        if (c->sb.multi_device)
diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
index eedffb505517..20e58258c813 100644
--- a/fs/bcachefs/inode.c
+++ b/fs/bcachefs/inode.c
@@ -1187,18 +1187,12 @@ int bch2_inode_rm(struct bch_fs *c, subvol_inum inum)
        return ret;
 }
 
-int bch2_inode_nlink_inc(struct bch_inode_unpacked *bi)
+void bch2_inode_nlink_inc(struct bch_inode_unpacked *bi)
 {
        if (bi->bi_flags & BCH_INODE_unlinked)
                bi->bi_flags &= ~BCH_INODE_unlinked;
-       else {
-               if (bi->bi_nlink == BCH_LINK_MAX - nlink_bias(bi->bi_mode))
-                       return -BCH_ERR_too_many_links;
-
+       else
                bi->bi_nlink++;
-       }
-
-       return 0;
 }
 
 void bch2_inode_nlink_dec(struct btree_trans *trans, struct bch_inode_unpacked 
*bi)
diff --git a/fs/bcachefs/inode.h b/fs/bcachefs/inode.h
index b8ec3e628d90..99de17e9f32c 100644
--- a/fs/bcachefs/inode.h
+++ b/fs/bcachefs/inode.h
@@ -285,7 +285,7 @@ static inline void bch2_inode_nlink_set(struct 
bch_inode_unpacked *bi,
        }
 }
 
-int bch2_inode_nlink_inc(struct bch_inode_unpacked *);
+void bch2_inode_nlink_inc(struct bch_inode_unpacked *);
 void bch2_inode_nlink_dec(struct btree_trans *, struct bch_inode_unpacked *);
 
 struct bch_opts bch2_inode_opts_to_opts(struct bch_inode_unpacked *);
diff --git a/fs/bcachefs/namei.c b/fs/bcachefs/namei.c
index c3f87c59922d..42e06baa2e43 100644
--- a/fs/bcachefs/namei.c
+++ b/fs/bcachefs/namei.c
@@ -221,9 +221,7 @@ int bch2_link_trans(struct btree_trans *trans,
                return ret;
 
        inode_u->bi_ctime = now;
-       ret = bch2_inode_nlink_inc(inode_u);
-       if (ret)
-               goto err;
+       bch2_inode_nlink_inc(inode_u);
 
        ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_intent);
        if (ret)
-- 
2.43.0