X-Git-Url: https://git.karo-electronics.de/?a=blobdiff_plain;f=include%2Flinux%2Fjournal-head.h;h=98cd41bb39c8667953c10030ef32f2945765f7e8;hb=7d769802427ef9a91eaf9b5a9a6283e71f2ba9d8;hp=13a3da25ff0752a99bccb12b9c105cdbdae13457;hpb=36a279686bc02d340eb213a9f2a0b67e50de64b4;p=karo-tx-linux.git

diff --git a/include/linux/journal-head.h b/include/linux/journal-head.h
index 13a3da25ff07..98cd41bb39c8 100644
--- a/include/linux/journal-head.h
+++ b/include/linux/journal-head.h
@@ -30,15 +30,19 @@ struct journal_head {
 
 	/*
 	 * Journalling list for this buffer [jbd_lock_bh_state()]
+	 * NOTE: We *cannot* combine this with b_modified into a bitfield
+	 * as gcc would then (which the C standard allows but which is
+	 * very unuseful) make 64-bit accesses to the bitfield and clobber
+	 * b_jcount if its update races with bitfield modification.
 	 */
-	unsigned b_jlist:4;
+	unsigned b_jlist;
 
 	/*
 	 * This flag signals the buffer has been modified by
 	 * the currently running transaction
 	 * [jbd_lock_bh_state()]
 	 */
-	unsigned b_modified:1;
+	unsigned b_modified;
 
 	/*
 	 * Copy of the buffer data frozen for writing to the log.