ext2: introduce helper for xattr header validation

Introduce helper function ext2_xattr_header_valid()
for xattr header validation and clean up the header
check ralated code.

Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Chengguang Xu <cgxu519@zoho.com.cn>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
index 1e33e0ac8cf1f8dbbaa8e364f5a6ca08a24d84ef..db27260d6a5b682b67447292c3f26c35955e804d 100644 (file)
--- a/fs/ext2/xattr.c
+++ b/fs/ext2/xattr.c
@@ -134,6 +134,16 @@ ext2_xattr_handler(int name_index)
        return handler;
 }
 
+static bool
+ext2_xattr_header_valid(struct ext2_xattr_header *header)
+{
+       if (header->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
+           header->h_blocks != cpu_to_le32(1))
+               return false;
+
+       return true;
+}
+
 /*
  * ext2_xattr_get()
  *
@@ -176,9 +186,9 @@ ext2_xattr_get(struct inode *inode, int name_index, const char *name,
        ea_bdebug(bh, "b_count=%d, refcount=%d",
                atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
        end = bh->b_data + bh->b_size;
-       if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
-           HDR(bh)->h_blocks != cpu_to_le32(1)) {
-bad_block:     ext2_error(inode->i_sb, "ext2_xattr_get",
+       if (!ext2_xattr_header_valid(HDR(bh))) {
+bad_block:
+               ext2_error(inode->i_sb, "ext2_xattr_get",
                        "inode %ld: bad block %d", inode->i_ino,
                        EXT2_I(inode)->i_file_acl);
                error = -EIO;
@@ -266,9 +276,9 @@ ext2_xattr_list(struct dentry *dentry, char *buffer, size_t buffer_size)
        ea_bdebug(bh, "b_count=%d, refcount=%d",
                atomic_read(&(bh->b_count)), le32_to_cpu(HDR(bh)->h_refcount));
        end = bh->b_data + bh->b_size;
-       if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
-           HDR(bh)->h_blocks != cpu_to_le32(1)) {
-bad_block:     ext2_error(inode->i_sb, "ext2_xattr_list",
+       if (!ext2_xattr_header_valid(HDR(bh))) {
+bad_block:
+               ext2_error(inode->i_sb, "ext2_xattr_list",
                        "inode %ld: bad block %d", inode->i_ino,
                        EXT2_I(inode)->i_file_acl);
                error = -EIO;
@@ -406,9 +416,9 @@ ext2_xattr_set(struct inode *inode, int name_index, const char *name,
                        le32_to_cpu(HDR(bh)->h_refcount));
                header = HDR(bh);
                end = bh->b_data + bh->b_size;
-               if (header->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
-                   header->h_blocks != cpu_to_le32(1)) {
-bad_block:             ext2_error(sb, "ext2_xattr_set",
+               if (!ext2_xattr_header_valid(header)) {
+bad_block:
+                       ext2_error(sb, "ext2_xattr_set",
                                "inode %ld: bad block %d", inode->i_ino, 
                                   EXT2_I(inode)->i_file_acl);
                        error = -EIO;
@@ -784,8 +794,7 @@ ext2_xattr_delete_inode(struct inode *inode)
                goto cleanup;
        }
        ea_bdebug(bh, "b_count=%d", atomic_read(&(bh->b_count)));
-       if (HDR(bh)->h_magic != cpu_to_le32(EXT2_XATTR_MAGIC) ||
-           HDR(bh)->h_blocks != cpu_to_le32(1)) {
+       if (!ext2_xattr_header_valid(HDR(bh))) {
                ext2_error(inode->i_sb, "ext2_xattr_delete_inode",
                        "inode %ld: bad block %d", inode->i_ino,
                        EXT2_I(inode)->i_file_acl);