[PATCH] jbd: avoid kfree(NULL) (304c4c84) · Commits · 戴 / test

There are a couple of places where JBD has to check to see whether an unneeded memory allocation was performed. Usually it _was_ needed, so we end up calling kfree(NULL). We can micro-optimise that by checking the pointer before calling kfree(). Thanks to Steven Rostedt <rostedt@goodmis.org> for identifying this. Signed-off-by:

Andrew Morton <akpm@osdl.org> Signed-off-by:

Linus Torvalds <torvalds@osdl.org>

fs/jbd/transaction.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -227,6 +227,7 @@ repeat_locked:
		spin_unlock(&transaction->t_handle_lock);
		spin_unlock(&journal->j_state_lock);
		out:
		if (unlikely(new_transaction)) /* It's usually NULL */
		kfree(new_transaction);
		return ret;
		}
		@@ -724,6 +725,7 @@ done:
		journal_cancel_revoke(handle, jh);

		out:
		if (unlikely(frozen_buffer)) /* It's usually NULL */
		kfree(frozen_buffer);

		JBUFFER_TRACE(jh, "exit");
		@@ -903,6 +905,7 @@ repeat:
		jbd_unlock_bh_state(bh);
		out:
		journal_put_journal_head(jh);
		if (unlikely(committed_data))
		kfree(committed_data);
		return err;
		}

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