ext4: simplify truncation code in ext4_setattr()

Merge conditions in ext4_setattr() handling inode size changes, also
move ext4_begin_ordered_truncate() call somewhat earlier because it
simplifies error recovery in case of failure. Also add error handling in
case i_disksize update fails.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: stable@vger.kernel.org

fs/ext4/inode.c

@@ -4600,7 +4600,9 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 		ext4_journal_stop(handle);
 	}
 
-	if (attr->ia_valid & ATTR_SIZE) {
+	if (attr->ia_valid & ATTR_SIZE && attr->ia_size != inode->i_size) {
+		handle_t *handle;
+		loff_t oldsize = inode->i_size;
 
 		if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
 			struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
@@ -4608,13 +4610,14 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 			if (attr->ia_size > sbi->s_bitmap_maxbytes)
 				return -EFBIG;
 		}
-	}
-
 		if (S_ISREG(inode->i_mode) &&
-	    attr->ia_valid & ATTR_SIZE &&
 		    (attr->ia_size < inode->i_size)) {
-		handle_t *handle;
-
+			if (ext4_should_order_data(inode)) {
+				error = ext4_begin_ordered_truncate(inode,
+							    attr->ia_size);
+				if (error)
+					goto err_out;
+			}
 			handle = ext4_journal_start(inode, EXT4_HT_INODE, 3);
 			if (IS_ERR(handle)) {
 				error = PTR_ERR(handle);
@@ -4629,29 +4632,11 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 			if (!error)
 				error = rc;
 			ext4_journal_stop(handle);
-
-		if (ext4_should_order_data(inode)) {
-			error = ext4_begin_ordered_truncate(inode,
-							    attr->ia_size);
 			if (error) {
-				/* Do as much error cleanup as possible */
-				handle = ext4_journal_start(inode,
-							    EXT4_HT_INODE, 3);
-				if (IS_ERR(handle)) {
 				ext4_orphan_del(NULL, inode);
 				goto err_out;
 			}
-				ext4_orphan_del(handle, inode);
-				orphan = 0;
-				ext4_journal_stop(handle);
-				goto err_out;
-			}
 		}
-	}
-
-	if (attr->ia_valid & ATTR_SIZE) {
-		if (attr->ia_size != inode->i_size) {
-			loff_t oldsize = inode->i_size;
 
 		i_size_write(inode, attr->ia_size);
 		/*
@@ -4673,8 +4658,12 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 		 */
 		truncate_pagecache(inode, oldsize, inode->i_size);
 	}
+	/*
+	 * We want to call ext4_truncate() even if attr->ia_size ==
+	 * inode->i_size for cases like truncation of fallocated space
+	 */
+	if (attr->ia_valid & ATTR_SIZE)
 		ext4_truncate(inode);
-	}
 
 	if (!rc) {
 		setattr_copy(inode, attr);