ext4: allow ext4_truncate() to return an error

This allows us to properly propagate errors back up to
ext4_truncate()'s callers.  This also means we no longer have to
silently ignore some errors (e.g., when trying to add the inode to the
orphan inode list).

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>

fs/ext4/ext4.h

@@ -2491,7 +2491,7 @@ extern int ext4_change_inode_journal_flag(struct inode *, int);
 extern int ext4_get_inode_loc(struct inode *, struct ext4_iloc *);
 extern int ext4_inode_attach_jinode(struct inode *inode);
 extern int ext4_can_truncate(struct inode *inode);
-extern void ext4_truncate(struct inode *);
+extern int ext4_truncate(struct inode *);
 extern int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length);
 extern int ext4_truncate_restart_trans(handle_t *, struct inode *, int nblocks);
 extern void ext4_set_inode_flags(struct inode *);

fs/ext4/inode.c

@@ -261,8 +261,15 @@ void ext4_evict_inode(struct inode *inode)
 			     "couldn't mark inode dirty (err %d)", err);
 		goto stop_handle;
 	}
-	if (inode->i_blocks)
-		ext4_truncate(inode);
+	if (inode->i_blocks) {
+		err = ext4_truncate(inode);
+		if (err) {
+			ext4_error(inode->i_sb,
+				   "couldn't truncate inode %lu (err %d)",
+				   inode->i_ino, err);
+			goto stop_handle;
+		}
+	}
 
 	/*
 	 * ext4_ext_truncate() doesn't reserve any slop when it
@@ -4097,10 +4104,11 @@ int ext4_inode_attach_jinode(struct inode *inode)
  * that's fine - as long as they are linked from the inode, the post-crash
  * ext4_truncate() run will find them and release them.
  */
-void ext4_truncate(struct inode *inode)
+int ext4_truncate(struct inode *inode)
 {
 	struct ext4_inode_info *ei = EXT4_I(inode);
 	unsigned int credits;
+	int err = 0;
 	handle_t *handle;
 	struct address_space *mapping = inode->i_mapping;
 
@@ -4114,7 +4122,7 @@ void ext4_truncate(struct inode *inode)
 	trace_ext4_truncate_enter(inode);
 
 	if (!ext4_can_truncate(inode))
-		return;
+		return 0;
 
 	ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
 
@@ -4126,13 +4134,13 @@ void ext4_truncate(struct inode *inode)
 
 		ext4_inline_data_truncate(inode, &has_inline);
 		if (has_inline)
-			return;
+			return 0;
 	}
 
 	/* If we zero-out tail of the page, we have to create jinode for jbd2 */
 	if (inode->i_size & (inode->i_sb->s_blocksize - 1)) {
 		if (ext4_inode_attach_jinode(inode) < 0)
-			return;
+			return 0;
 	}
 
 	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
@@ -4141,10 +4149,8 @@ void ext4_truncate(struct inode *inode)
 		credits = ext4_blocks_for_truncate(inode);
 
 	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
-	if (IS_ERR(handle)) {
-		ext4_std_error(inode->i_sb, PTR_ERR(handle));
-		return;
-	}
+	if (IS_ERR(handle))
+		return PTR_ERR(handle);
 
 	if (inode->i_size & (inode->i_sb->s_blocksize - 1))
 		ext4_block_truncate_page(handle, mapping, inode->i_size);
@@ -4158,7 +4164,8 @@ void ext4_truncate(struct inode *inode)
 	 * Implication: the file must always be in a sane, consistent
 	 * truncatable state while each transaction commits.
 	 */
-	if (ext4_orphan_add(handle, inode))
+	err = ext4_orphan_add(handle, inode);
+	if (err)
 		goto out_stop;
 
 	down_write(&EXT4_I(inode)->i_data_sem);
@@ -4191,6 +4198,7 @@ out_stop:
 	ext4_journal_stop(handle);
 
 	trace_ext4_truncate_exit(inode);
+	return err;
 }
 
 /*
@@ -5205,12 +5213,15 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 		 * in data=journal mode to make pages freeable.
 		 */
 		truncate_pagecache(inode, inode->i_size);
-		if (shrink)
-			ext4_truncate(inode);
+		if (shrink) {
+			rc = ext4_truncate(inode);
+			if (rc)
+				error = rc;
+		}
 		up_write(&EXT4_I(inode)->i_mmap_sem);
 	}
 
-	if (!rc) {
+	if (!error) {
 		setattr_copy(inode, attr);
 		mark_inode_dirty(inode);
 	}
@@ -5222,7 +5233,7 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
 	if (orphan && inode->i_nlink)
 		ext4_orphan_del(NULL, inode);
 
-	if (!rc && (ia_valid & ATTR_MODE))
+	if (!error && (ia_valid & ATTR_MODE))
 		rc = posix_acl_chmod(inode, inode->i_mode);
 
 err_out:

fs/ext4/ioctl.c

@@ -248,8 +248,11 @@ static int ext4_ioctl_setflags(struct inode *inode,
 			err = -EOPNOTSUPP;
 			goto flags_out;
 		}
-	} else if (oldflags & EXT4_EOFBLOCKS_FL)
-		ext4_truncate(inode);
+	} else if (oldflags & EXT4_EOFBLOCKS_FL) {
+		err = ext4_truncate(inode);
+		if (err)
+			goto flags_out;
+	}
 
 	handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
 	if (IS_ERR(handle)) {

fs/ext4/super.c

@@ -2330,7 +2330,7 @@ static void ext4_orphan_cleanup(struct super_block *sb,
 				struct ext4_super_block *es)
 {
 	unsigned int s_flags = sb->s_flags;
-	int nr_orphans = 0, nr_truncates = 0;
+	int ret, nr_orphans = 0, nr_truncates = 0;
 #ifdef CONFIG_QUOTA
 	int i;
 #endif
@@ -2412,7 +2412,9 @@ static void ext4_orphan_cleanup(struct super_block *sb,
 				  inode->i_ino, inode->i_size);
 			inode_lock(inode);
 			truncate_inode_pages(inode->i_mapping, inode->i_size);
-			ext4_truncate(inode);
+			ret = ext4_truncate(inode);
+			if (ret)
+				ext4_std_error(inode->i_sb, ret);
 			inode_unlock(inode);
 			nr_truncates++;
 		} else {