[PATCH v3 4/9] ntfs: return errors from ntfs_attr_readall

ntfs_attr_readall() currently loses the failure reason for attribute
lookup, allocation, and read failures by returning NULL. Return ERR_PTR()
with the original error instead.

The reparse parser can then propagate allocation and I/O errors without
treating them as filesystem corruption.

Signed-off-by: Hyunchul Lee <[email protected]>
---
 fs/ntfs/attrib.c  |  8 +++++++-
 fs/ntfs/ea.c      | 38 +++++++++++++++++++++++++++++++-------
 fs/ntfs/index.c   |  4 ++--
 fs/ntfs/reparse.c |  4 ++++
 4 files changed, 44 insertions(+), 10 deletions(-)

diff --git a/fs/ntfs/attrib.c b/fs/ntfs/attrib.c
index 990c3937a551..d9e844c481d8 100644
--- a/fs/ntfs/attrib.c
+++ b/fs/ntfs/attrib.c
@@ -5296,6 +5296,7 @@ int ntfs_attr_remove(struct ntfs_inode *ni, const __le32 type, __le16 *name,
  * On success a buffer is allocated with the content of the attribute
  * and which needs to be freed when it's not needed anymore. If the
  * @data_size parameter is non-NULL then the data size is set there.
+ * On error, an ERR_PTR() containing the negative error code is returned.
  */
 void *ntfs_attr_readall(struct ntfs_inode *ni, const __le32 type,
 		__le16 *name, u32 name_len, s64 *data_size)
@@ -5310,6 +5311,7 @@ void *ntfs_attr_readall(struct ntfs_inode *ni, const __le32 type,
 
 	bmp_vi = ntfs_attr_iget(VFS_I(ni), type, name, name_len);
 	if (IS_ERR(bmp_vi)) {
+		ret = ERR_PTR(PTR_ERR(bmp_vi));
 		ntfs_debug("ntfs_attr_iget failed");
 		goto err_exit;
 	}
@@ -5319,17 +5321,21 @@ void *ntfs_attr_readall(struct ntfs_inode *ni, const __le32 type,
 		(bmp_ni->type != AT_BITMAP ||
 		bmp_ni->data_size > ((ni->vol->nr_clusters + 7) >> 3))) {
 		ntfs_error(sb, "Invalid attribute data size");
+		ret = ERR_PTR(-EIO);
 		goto out;
 	}
 
 	data = kvmalloc(bmp_ni->data_size, GFP_NOFS);
-	if (!data)
+	if (!data) {
+		ret = ERR_PTR(-ENOMEM);
 		goto out;
+	}
 
 	size = ntfs_inode_attr_pread(VFS_I(bmp_ni), 0, bmp_ni->data_size,
 			(u8 *)data);
 	if (size != bmp_ni->data_size) {
 		ntfs_error(sb, "ntfs_attr_pread failed");
+		ret = size < 0 ? ERR_PTR((int)size) : ERR_PTR(-EIO);
 		kvfree(data);
 		goto out;
 	}
diff --git a/fs/ntfs/ea.c b/fs/ntfs/ea.c
index fc6cec7ce130..c8a3d9f07dc4 100644
--- a/fs/ntfs/ea.c
+++ b/fs/ntfs/ea.c
@@ -122,17 +122,19 @@ static int ntfs_get_ea(struct inode *inode, const char *name, size_t name_len,
 
 	p_ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
 			&ea_info_size);
-	if (!p_ea_info || ea_info_size != sizeof(struct ea_information)) {
+	if (IS_ERR(p_ea_info))
+		return PTR_ERR(p_ea_info);
+	if (ea_info_size != sizeof(struct ea_information)) {
 		kvfree(p_ea_info);
-		return -ENODATA;
+		return -EIO;
 	}
 
 	ea_info_qlen = le32_to_cpu(p_ea_info->ea_query_length);
 	kvfree(p_ea_info);
 
 	ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &all_ea_size);
-	if (!ea_buf)
-		return -ENODATA;
+	if (IS_ERR(ea_buf))
+		return PTR_ERR(ea_buf);
 
 	if (ea_info_qlen > all_ea_size) {
 		err = -EIO;
@@ -208,10 +210,22 @@ static int ntfs_set_ea(struct inode *inode, const char *name, size_t name_len,
 	if (ntfs_attr_exist(ni, AT_EA_INFORMATION, AT_UNNAMED, 0)) {
 		p_ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
 						&ea_info_size);
-		if (!p_ea_info || ea_info_size != sizeof(struct ea_information))
+		if (IS_ERR(p_ea_info)) {
+			err = PTR_ERR(p_ea_info);
+			p_ea_info = NULL;
 			goto out;
+		}
+		if (ea_info_size != sizeof(struct ea_information)) {
+			err = -EIO;
+			goto out;
+		}
 
 		ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &all_ea_size);
+		if (IS_ERR(ea_buf)) {
+			err = PTR_ERR(ea_buf);
+			ea_buf = NULL;
+			goto out;
+		}
 		if (!ea_buf) {
 			ea_info_qsize = 0;
 			kvfree(p_ea_info);
@@ -514,14 +528,24 @@ ssize_t ntfs_listxattr(struct dentry *dentry, char *buffer, size_t size)
 	mutex_lock(&NTFS_I(inode)->mrec_lock);
 	ea_info = ntfs_attr_readall(ni, AT_EA_INFORMATION, NULL, 0,
 			&ea_info_size);
-	if (!ea_info || ea_info_size != sizeof(struct ea_information))
+	if (IS_ERR(ea_info)) {
+		err = PTR_ERR(ea_info);
+		ea_info = NULL;
 		goto out;
+	}
+	if (ea_info_size != sizeof(struct ea_information)) {
+		err = -EIO;
+		goto out;
+	}
 
 	ea_info_qsize = le32_to_cpu(ea_info->ea_query_length);
 
 	ea_buf = ntfs_attr_readall(ni, AT_EA, NULL, 0, &ea_buf_size);
-	if (!ea_buf)
+	if (IS_ERR(ea_buf)) {
+		err = PTR_ERR(ea_buf);
+		ea_buf = NULL;
 		goto out;
+	}
 
 	if (ea_info_qsize > ea_buf_size || ea_info_qsize == 0)
 		goto out;
diff --git a/fs/ntfs/index.c b/fs/ntfs/index.c
index 8c8eb13859ab..46a8b19c0723 100644
--- a/fs/ntfs/index.c
+++ b/fs/ntfs/index.c
@@ -1108,8 +1108,8 @@ static s64 ntfs_ibm_get_free(struct ntfs_index_context *icx)
 
 	bm = ntfs_attr_readall(icx->idx_ni, AT_BITMAP,  icx->name, icx->name_len,
 			&size);
-	if (!bm)
-		return -EIO;
+	if (IS_ERR(bm))
+		return PTR_ERR(bm);
 
 	for (byte = 0; byte < size; byte++) {
 		if (bm[byte] == 255)
diff --git a/fs/ntfs/reparse.c b/fs/ntfs/reparse.c
index 0d3988992119..b8d601f5500f 100644
--- a/fs/ntfs/reparse.c
+++ b/fs/ntfs/reparse.c
@@ -256,6 +256,8 @@ unsigned int ntfs_make_symlink(struct ntfs_inode *ni)
 
 	reparse_attr = ntfs_attr_readall(ni, AT_REPARSE_POINT, NULL, 0,
 					 &attr_size);
+	if (IS_ERR(reparse_attr))
+		reparse_attr = NULL;
 	if (reparse_attr &&
 	    valid_reparse_data(ni, reparse_attr, attr_size)) {
 		err = -EINVAL;
@@ -335,6 +337,8 @@ unsigned int ntfs_reparse_tag_dt_types(struct ntfs_volume *vol, unsigned long mr
 
 	reparse_attr = (struct reparse_point *)ntfs_attr_readall(NTFS_I(vi),
 			AT_REPARSE_POINT, NULL, 0, &attr_size);
+	if (IS_ERR(reparse_attr))
+		reparse_attr = NULL;
 
 	if (reparse_attr && attr_size >= sizeof(*reparse_attr)) {
 		switch (reparse_attr->reparse_tag) {

-- 
2.43.0