Merge tag 'erofs-for-6.12-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs

Pull erofs fixes from Gao Xiang:
 "The main one fixes a syzbot issue due to the invalid inode type out of
  file-backed mounts. The others are minor cleanups without actual logic
  changes.

  Summary:

   - Make sure only regular inodes can be used for file-backed mounts

   - Two minor codebase cleanups"

* tag 'erofs-for-6.12-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: get rid of kaddr in `struct z_erofs_maprecorder`
  erofs: get rid of z_erofs_try_to_claim_pcluster()
  erofs: ensure regular inodes for file-backed mounts

1 files changed, 12 insertions, 20 deletions

diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 1253a8456e59..a076cca1f547 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -10,8 +10,6 @@
 struct z_erofs_maprecorder {
 	struct inode *inode;
 	struct erofs_map_blocks *map;
-	void *kaddr;
-
 	unsigned long lcn;
 	/* compression extent information gathered */
 	u8  type, headtype;
@@ -33,14 +31,11 @@ static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m,
 	struct z_erofs_lcluster_index *di;
 	unsigned int advise;
 
-	m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb,
-				      pos, EROFS_KMAP);
-	if (IS_ERR(m->kaddr))
-		return PTR_ERR(m->kaddr);
-
-	m->nextpackoff = pos + sizeof(struct z_erofs_lcluster_index);
+	di = erofs_read_metabuf(&m->map->buf, inode->i_sb, pos, EROFS_KMAP);
+	if (IS_ERR(di))
+		return PTR_ERR(di);
 	m->lcn = lcn;
-	di = m->kaddr;
+	m->nextpackoff = pos + sizeof(struct z_erofs_lcluster_index);
 
 	advise = le16_to_cpu(di->di_advise);
 	m->type = advise & Z_EROFS_LI_LCLUSTER_TYPE_MASK;
@@ -53,8 +48,7 @@ static int z_erofs_load_full_lcluster(struct z_erofs_maprecorder *m,
 				DBG_BUGON(1);
 				return -EFSCORRUPTED;
 			}
-			m->compressedblks = m->delta[0] &
-				~Z_EROFS_LI_D0_CBLKCNT;
+			m->compressedblks = m->delta[0] & ~Z_EROFS_LI_D0_CBLKCNT;
 			m->delta[0] = 1;
 		}
 		m->delta[1] = le16_to_cpu(di->di_u.delta[1]);
@@ -110,9 +104,9 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 	struct erofs_inode *const vi = EROFS_I(m->inode);
 	const unsigned int lclusterbits = vi->z_logical_clusterbits;
 	unsigned int vcnt, lo, lobits, encodebits, nblk, bytes;
-	int i;
-	u8 *in, type;
 	bool big_pcluster;
+	u8 *in, type;
+	int i;
 
 	if (1 << amortizedshift == 4 && lclusterbits <= 14)
 		vcnt = 2;
@@ -121,6 +115,10 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 	else
 		return -EOPNOTSUPP;
 
+	in = erofs_read_metabuf(&m->map->buf, m->inode->i_sb, pos, EROFS_KMAP);
+	if (IS_ERR(in))
+		return PTR_ERR(in);
+
 	/* it doesn't equal to round_up(..) */
 	m->nextpackoff = round_down(pos, vcnt << amortizedshift) +
 			 (vcnt << amortizedshift);
@@ -128,9 +126,7 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 	lobits = max(lclusterbits, ilog2(Z_EROFS_LI_D0_CBLKCNT) + 1U);
 	encodebits = ((vcnt << amortizedshift) - sizeof(__le32)) * 8 / vcnt;
 	bytes = pos & ((vcnt << amortizedshift) - 1);
-
-	in = m->kaddr - bytes;
-
+	in -= bytes;
 	i = bytes >> amortizedshift;
 
 	lo = decode_compactedbits(lobits, in, encodebits * i, &type);
@@ -255,10 +251,6 @@ static int z_erofs_load_compact_lcluster(struct z_erofs_maprecorder *m,
 	amortizedshift = 2;
 out:
 	pos += lcn * (1 << amortizedshift);
-	m->kaddr = erofs_read_metabuf(&m->map->buf, inode->i_sb,
-				      pos, EROFS_KMAP);
-	if (IS_ERR(m->kaddr))
-		return PTR_ERR(m->kaddr);
 	return unpack_compacted_index(m, amortizedshift, pos, lookahead);
 }