From 962ad1a76669443126c6531352380f56d6e5d7d2 Mon Sep 17 00:00:00 2001
From: Kent Overstreet <kent.overstreet@gmail.com>
Date: Thu, 23 Jun 2022 18:26:01 -0400
Subject: [PATCH] bcachefs: Don't BUG_ON() inode link count underflow
This switches that assertion to a bch2_trans_inconsistent() call, as it
should be.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
---
fs/bcachefs/fs-common.c | 8 +++++---
fs/bcachefs/inode.c | 33 +++++++++++++++++++++++++++++++++
fs/bcachefs/inode.h | 20 +++-----------------
3 files changed, 41 insertions(+), 20 deletions(-)
diff --git a/fs/bcachefs/fs-common.c b/fs/bcachefs/fs-common.c
index d543480be1117..53ffc684223cf 100644
--- a/fs/bcachefs/fs-common.c
+++ b/fs/bcachefs/fs-common.c
@@ -204,7 +204,9 @@ int bch2_link_trans(struct btree_trans *trans,
goto err;
inode_u->bi_ctime = now;
- bch2_inode_nlink_inc(inode_u);
+ ret = bch2_inode_nlink_inc(inode_u);
+ if (ret)
+ return ret;
ret = bch2_inode_peek(trans, &dir_iter, dir_u, dir, BTREE_ITER_INTENT);
if (ret)
@@ -297,7 +299,7 @@ int bch2_unlink_trans(struct btree_trans *trans,
if (ret)
goto err;
} else {
- bch2_inode_nlink_dec(inode_u);
+ bch2_inode_nlink_dec(trans, inode_u);
}
if (inode_u->bi_dir == dirent_iter.pos.inode &&
@@ -462,7 +464,7 @@ int bch2_rename_trans(struct btree_trans *trans,
}
if (mode == BCH_RENAME_OVERWRITE)
- bch2_inode_nlink_dec(dst_inode_u);
+ bch2_inode_nlink_dec(trans, dst_inode_u);
src_dir_u->bi_mtime = now;
src_dir_u->bi_ctime = now;
diff --git a/fs/bcachefs/inode.c b/fs/bcachefs/inode.c
index 6c0547151d507..5de66d62028b2 100644
--- a/fs/bcachefs/inode.c
+++ b/fs/bcachefs/inode.c
@@ -716,3 +716,36 @@ int bch2_inode_find_by_inum(struct bch_fs *c, subvol_inum inum,
return bch2_trans_do(c, NULL, NULL, 0,
bch2_inode_find_by_inum_trans(&trans, inum, inode));
}
+
+int 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 == U32_MAX)
+ return -EINVAL;
+
+ bi->bi_nlink++;
+ }
+
+ return 0;
+}
+
+void bch2_inode_nlink_dec(struct btree_trans *trans, struct bch_inode_unpacked *bi)
+{
+ if (bi->bi_nlink && (bi->bi_flags & BCH_INODE_UNLINKED)) {
+ bch2_trans_inconsistent(trans, "inode %llu unlinked but link count nonzero",
+ bi->bi_inum);
+ return;
+ }
+
+ if (bi->bi_flags & BCH_INODE_UNLINKED) {
+ bch2_trans_inconsistent(trans, "inode %llu link count underflow", bi->bi_inum);
+ return;
+ }
+
+ if (bi->bi_nlink)
+ bi->bi_nlink--;
+ else
+ bi->bi_flags |= BCH_INODE_UNLINKED;
+}
diff --git a/fs/bcachefs/inode.h b/fs/bcachefs/inode.h
index 9442600a7440e..2ac2fc10513bb 100644
--- a/fs/bcachefs/inode.h
+++ b/fs/bcachefs/inode.h
@@ -164,23 +164,6 @@ static inline unsigned nlink_bias(umode_t mode)
return S_ISDIR(mode) ? 2 : 1;
}
-static inline void bch2_inode_nlink_inc(struct bch_inode_unpacked *bi)
-{
- if (bi->bi_flags & BCH_INODE_UNLINKED)
- bi->bi_flags &= ~BCH_INODE_UNLINKED;
- else
- bi->bi_nlink++;
-}
-
-static inline void bch2_inode_nlink_dec(struct bch_inode_unpacked *bi)
-{
- BUG_ON(bi->bi_flags & BCH_INODE_UNLINKED);
- if (bi->bi_nlink)
- bi->bi_nlink--;
- else
- bi->bi_flags |= BCH_INODE_UNLINKED;
-}
-
static inline unsigned bch2_inode_nlink_get(struct bch_inode_unpacked *bi)
{
return bi->bi_flags & BCH_INODE_UNLINKED
@@ -200,4 +183,7 @@ 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_dec(struct btree_trans *, struct bch_inode_unpacked *);
+
#endif /* _BCACHEFS_INODE_H */
--
2.30.2