Merge tag 'erofs-for-6.0-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs

Pull erofs fixes from Gao Xiang:

 - Fix return codes in erofs_fscache_{meta_,}read_folio error paths

 - Fix potential wrong pcluster sizes for later non-4K lclusters

 - Fix in-memory pcluster use-after-free on UP platforms

* tag 'erofs-for-6.0-rc5-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs:
  erofs: fix pcluster use-after-free on UP platforms
  erofs: avoid the potentially wrong m_plen for big pcluster
  erofs: fix error return code in erofs_fscache_{meta_,}read_folio

Author: torvalds

fs/erofs/fscache.c

@@ -222,8 +222,10 @@ static int erofs_fscache_meta_read_folio(struct file *data, struct folio *folio)
 
 	rreq = erofs_fscache_alloc_request(folio_mapping(folio),
 				folio_pos(folio), folio_size(folio));
-	if (IS_ERR(rreq))
+	if (IS_ERR(rreq)) {
+		ret = PTR_ERR(rreq);
 		goto out;
+	}
 
 	return erofs_fscache_read_folios_async(mdev.m_fscache->cookie,
 				rreq, mdev.m_pa);
@@ -301,8 +303,10 @@ static int erofs_fscache_read_folio(struct file *file, struct folio *folio)
 
 	rreq = erofs_fscache_alloc_request(folio_mapping(folio),
 				folio_pos(folio), folio_size(folio));
-	if (IS_ERR(rreq))
+	if (IS_ERR(rreq)) {
+		ret = PTR_ERR(rreq);
 		goto out_unlock;
+	}
 
 	pstart = mdev.m_pa + (pos - map.m_la);
 	return erofs_fscache_read_folios_async(mdev.m_fscache->cookie,

fs/erofs/internal.h

@@ -195,7 +195,6 @@ struct erofs_workgroup {
 	atomic_t refcount;
 };
 
-#if defined(CONFIG_SMP)
 static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
 						 int val)
 {
@@ -224,34 +223,6 @@ static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
 	return atomic_cond_read_relaxed(&grp->refcount,
 					VAL != EROFS_LOCKED_MAGIC);
 }
-#else
-static inline bool erofs_workgroup_try_to_freeze(struct erofs_workgroup *grp,
-						 int val)
-{
-	preempt_disable();
-	/* no need to spin on UP platforms, let's just disable preemption. */
-	if (val != atomic_read(&grp->refcount)) {
-		preempt_enable();
-		return false;
-	}
-	return true;
-}
-
-static inline void erofs_workgroup_unfreeze(struct erofs_workgroup *grp,
-					    int orig_val)
-{
-	preempt_enable();
-}
-
-static inline int erofs_wait_on_workgroup_freezed(struct erofs_workgroup *grp)
-{
-	int v = atomic_read(&grp->refcount);
-
-	/* workgroup is never freezed on uniprocessor systems */
-	DBG_BUGON(v == EROFS_LOCKED_MAGIC);
-	return v;
-}
-#endif	/* !CONFIG_SMP */
 #endif	/* !CONFIG_EROFS_FS_ZIP */
 
 /* we strictly follow PAGE_SIZE and no buffer head yet */

fs/erofs/zmap.c

@@ -141,7 +141,7 @@ struct z_erofs_maprecorder {
 	u8  type, headtype;
 	u16 clusterofs;
 	u16 delta[2];
-	erofs_blk_t pblk, compressedlcs;
+	erofs_blk_t pblk, compressedblks;
 	erofs_off_t nextpackoff;
 };
 
@@ -192,7 +192,7 @@ static int legacy_load_cluster_from_disk(struct z_erofs_maprecorder *m,
 				DBG_BUGON(1);
 				return -EFSCORRUPTED;
 			}
-			m->compressedlcs = m->delta[0] &
+			m->compressedblks = m->delta[0] &
 				~Z_EROFS_VLE_DI_D0_CBLKCNT;
 			m->delta[0] = 1;
 		}
@@ -293,7 +293,7 @@ static int unpack_compacted_index(struct z_erofs_maprecorder *m,
 				DBG_BUGON(1);
 				return -EFSCORRUPTED;
 			}
-			m->compressedlcs = lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
+			m->compressedblks = lo & ~Z_EROFS_VLE_DI_D0_CBLKCNT;
 			m->delta[0] = 1;
 			return 0;
 		} else if (i + 1 != (int)vcnt) {
@@ -497,7 +497,7 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
 		return 0;
 	}
 	lcn = m->lcn + 1;
-	if (m->compressedlcs)
+	if (m->compressedblks)
 		goto out;
 
 	err = z_erofs_load_cluster_from_disk(m, lcn, false);
@@ -506,7 +506,7 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
 
 	/*
 	 * If the 1st NONHEAD lcluster has already been handled initially w/o
-	 * valid compressedlcs, which means at least it mustn't be CBLKCNT, or
+	 * valid compressedblks, which means at least it mustn't be CBLKCNT, or
 	 * an internal implemenatation error is detected.
 	 *
 	 * The following code can also handle it properly anyway, but let's
@@ -523,12 +523,12 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
 		 * if the 1st NONHEAD lcluster is actually PLAIN or HEAD type
 		 * rather than CBLKCNT, it's a 1 lcluster-sized pcluster.
 		 */
-		m->compressedlcs = 1;
+		m->compressedblks = 1 << (lclusterbits - LOG_BLOCK_SIZE);
 		break;
 	case Z_EROFS_VLE_CLUSTER_TYPE_NONHEAD:
 		if (m->delta[0] != 1)
 			goto err_bonus_cblkcnt;
-		if (m->compressedlcs)
+		if (m->compressedblks)
 			break;
 		fallthrough;
 	default:
@@ -539,7 +539,7 @@ static int z_erofs_get_extent_compressedlen(struct z_erofs_maprecorder *m,
 		return -EFSCORRUPTED;
 	}
 out:
-	map->m_plen = (u64)m->compressedlcs << lclusterbits;
+	map->m_plen = (u64)m->compressedblks << LOG_BLOCK_SIZE;
 	return 0;
 err_bonus_cblkcnt:
 	erofs_err(m->inode->i_sb,