staging: erofs: introduce EFSCORRUPTED and more logs

Previously, EROFS uses EIO to indicate that filesystem
is corrupted as well. However, as Pavel said [1], other
filesystems tend to use EUCLEAN(EFSCORRUPTED) instead,
let's follow what others do right now.

Also, add some more prints to the syslog.

[1] https://lore.kernel.org/lkml/20190813114821.GB11559@amd/Suggested-by: Pavel Machek <pavel@denx.de>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190814103705.60698-1-gaoxiang25@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/erofs/data.c

@@ -143,10 +143,12 @@ static int erofs_map_blocks_flatmode(struct inode *inode,
 			vi->xattr_isize + erofs_blkoff(map->m_la);
 		map->m_plen = inode->i_size - offset;
 
-		/* inline data should locate in one meta block */
+		/* inline data should be located in one meta block */
 		if (erofs_blkoff(map->m_pa) + map->m_plen > PAGE_SIZE) {
+			errln("inline data cross block boundary @ nid %llu",
+			      vi->nid);
 			DBG_BUGON(1);
-			err = -EIO;
+			err = -EFSCORRUPTED;
 			goto err_out;
 		}
 

drivers/staging/erofs/dir.c

@@ -34,7 +34,7 @@ static void debug_one_dentry(unsigned char d_type, const char *de_name,
 #endif
 }
 
-static int erofs_fill_dentries(struct dir_context *ctx,
+static int erofs_fill_dentries(struct inode *dir, struct dir_context *ctx,
 			       void *dentry_blk, unsigned int *ofs,
 			       unsigned int nameoff, unsigned int maxsize)
 {
@@ -63,8 +63,9 @@ static int erofs_fill_dentries(struct dir_context *ctx,
 		/* a corrupted entry is found */
 		if (unlikely(nameoff + de_namelen > maxsize ||
 			     de_namelen > EROFS_NAME_LEN)) {
+			errln("bogus dirent @ nid %llu", EROFS_V(dir)->nid);
 			DBG_BUGON(1);
-			return -EIO;
+			return -EFSCORRUPTED;
 		}
 
 		debug_one_dentry(d_type, de_name, de_namelen);
@@ -104,10 +105,9 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx)
 
 		if (unlikely(nameoff < sizeof(struct erofs_dirent) ||
 			     nameoff >= PAGE_SIZE)) {
-			errln("%s, invalid de[0].nameoff %u",
-			      __func__, nameoff);
-
-			err = -EIO;
+			errln("%s, invalid de[0].nameoff %u @ nid %llu",
+			      __func__, nameoff, EROFS_V(dir)->nid);
+			err = -EFSCORRUPTED;
 			goto skip_this;
 		}
 
@@ -123,7 +123,8 @@ static int erofs_readdir(struct file *f, struct dir_context *ctx)
 				goto skip_this;
 		}
 
-		err = erofs_fill_dentries(ctx, de, &ofs, nameoff, maxsize);
+		err = erofs_fill_dentries(dir, ctx, de, &ofs,
+					  nameoff, maxsize);
 skip_this:
 		kunmap(dentry_page);
 

drivers/staging/erofs/inode.c

@@ -43,7 +43,7 @@ static int read_inode(struct inode *inode, void *data)
 		else if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode))
 			inode->i_rdev = 0;
 		else
-			return -EIO;
+			goto bogusimode;
 
 		i_uid_write(inode, le32_to_cpu(v2->i_uid));
 		i_gid_write(inode, le32_to_cpu(v2->i_gid));
@@ -76,7 +76,7 @@ static int read_inode(struct inode *inode, void *data)
 		else if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode))
 			inode->i_rdev = 0;
 		else
-			return -EIO;
+			goto bogusimode;
 
 		i_uid_write(inode, le16_to_cpu(v1->i_uid));
 		i_gid_write(inode, le16_to_cpu(v1->i_gid));
@@ -104,6 +104,11 @@ static int read_inode(struct inode *inode, void *data)
 	else
 		inode->i_blocks = nblks << LOG_SECTORS_PER_BLOCK;
 	return 0;
+
+bogusimode:
+	errln("bogus i_mode (%o) @ nid %llu", inode->i_mode, vi->nid);
+	DBG_BUGON(1);
+	return -EFSCORRUPTED;
 }
 
 /*
@@ -137,9 +142,11 @@ static int fill_inline_data(struct inode *inode, void *data,
 
 		/* inline symlink data shouldn't across page boundary as well */
 		if (unlikely(m_pofs + inode->i_size > PAGE_SIZE)) {
-			DBG_BUGON(1);
 			kfree(lnk);
-			return -EIO;
+			errln("inline data cross block boundary @ nid %llu",
+			      vi->nid);
+			DBG_BUGON(1);
+			return -EFSCORRUPTED;
 		}
 
 		/* get in-page inline data */
@@ -201,7 +208,7 @@ static int fill_inode(struct inode *inode, int isdir)
 			init_special_inode(inode, inode->i_mode, inode->i_rdev);
 			goto out_unlock;
 		} else {
-			err = -EIO;
+			err = -EFSCORRUPTED;
 			goto out_unlock;
 		}
 

drivers/staging/erofs/internal.h

@@ -548,5 +548,7 @@ static inline int z_erofs_init_zip_subsystem(void) { return 0; }
 static inline void z_erofs_exit_zip_subsystem(void) {}
 #endif	/* !CONFIG_EROFS_FS_ZIP */
 
+#define EFSCORRUPTED    EUCLEAN         /* Filesystem is corrupted */
+
 #endif	/* __EROFS_INTERNAL_H */
 

drivers/staging/erofs/namei.c

@@ -116,10 +116,12 @@ static struct page *find_target_block_classic(struct inode *dir,
 			struct erofs_qstr dname;
 
 			if (unlikely(!ndirents)) {
-				DBG_BUGON(1);
 				kunmap_atomic(de);
 				put_page(page);
-				page = ERR_PTR(-EIO);
+				errln("corrupted dir block %d @ nid %llu",
+				      mid, EROFS_V(dir)->nid);
+				DBG_BUGON(1);
+				page = ERR_PTR(-EFSCORRUPTED);
 				goto out;
 			}
 

drivers/staging/erofs/xattr.c

@@ -75,8 +75,9 @@ static int init_inode_xattrs(struct inode *inode)
 		goto out_unlock;
 	} else if (vi->xattr_isize < sizeof(struct erofs_xattr_ibody_header)) {
 		if (unlikely(vi->xattr_isize)) {
+			errln("bogus xattr ibody @ nid %llu", vi->nid);
 			DBG_BUGON(1);
-			ret = -EIO;
+			ret = -EFSCORRUPTED;
 			goto out_unlock;	/* xattr ondisk layout error */
 		}
 		ret = -ENOATTR;
@@ -237,7 +238,7 @@ static int xattr_foreach(struct xattr_iter *it,
 		/* xattr on-disk corruption: xattr entry beyond xattr_isize */
 		if (unlikely(*tlimit < entry_sz)) {
 			DBG_BUGON(1);
-			return -EIO;
+			return -EFSCORRUPTED;
 		}
 		*tlimit -= entry_sz;
 	}

drivers/staging/erofs/zmap.c

@@ -338,8 +338,9 @@ static int vle_extent_lookback(struct z_erofs_maprecorder *m,
 	int err;
 
 	if (lcn < lookback_distance) {
+		errln("bogus lookback distance @ nid %llu", vi->nid);
 		DBG_BUGON(1);
-		return -EIO;
+		return -EFSCORRUPTED;
 	}
 
 	/* load extent head logical cluster if needed */
@@ -419,7 +420,7 @@ int z_erofs_map_blocks_iter(struct inode *inode,
 		if (unlikely(!m.lcn)) {
 			errln("invalid logical cluster 0 at nid %llu",
 			      vi->nid);
-			err = -EIO;
+			err = -EFSCORRUPTED;
 			goto unmap_out;
 		}
 		end = (m.lcn << lclusterbits) | m.clusterofs;