[XFS] Push some common code out of write path into core XFS code for
sharing.
SGI-PV: 904196
SGI-Modid: xfs-linux-melb:xfs-kern:26248a
Signed-off-by: Nathan Scott <nathans@sgi.com>
diff --git a/fs/xfs/xfs_rw.c b/fs/xfs/xfs_rw.c
index d33e4f5..c55e281 100644
--- a/fs/xfs/xfs_rw.c
+++ b/fs/xfs/xfs_rw.c
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
* All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
@@ -92,6 +92,90 @@
}
/*
+ * Handle logging requirements of various synchronous types of write.
+ */
+int
+xfs_write_sync_logforce(
+ xfs_mount_t *mp,
+ xfs_inode_t *ip)
+{
+ int error = 0;
+
+ /*
+ * If we're treating this as O_DSYNC and we have not updated the
+ * size, force the log.
+ */
+ if (!(mp->m_flags & XFS_MOUNT_OSYNCISOSYNC) &&
+ !(ip->i_update_size)) {
+ xfs_inode_log_item_t *iip = ip->i_itemp;
+
+ /*
+ * If an allocation transaction occurred
+ * without extending the size, then we have to force
+ * the log up the proper point to ensure that the
+ * allocation is permanent. We can't count on
+ * the fact that buffered writes lock out direct I/O
+ * writes - the direct I/O write could have extended
+ * the size nontransactionally, then finished before
+ * we started. xfs_write_file will think that the file
+ * didn't grow but the update isn't safe unless the
+ * size change is logged.
+ *
+ * Force the log if we've committed a transaction
+ * against the inode or if someone else has and
+ * the commit record hasn't gone to disk (e.g.
+ * the inode is pinned). This guarantees that
+ * all changes affecting the inode are permanent
+ * when we return.
+ */
+ if (iip && iip->ili_last_lsn) {
+ xfs_log_force(mp, iip->ili_last_lsn,
+ XFS_LOG_FORCE | XFS_LOG_SYNC);
+ } else if (xfs_ipincount(ip) > 0) {
+ xfs_log_force(mp, (xfs_lsn_t)0,
+ XFS_LOG_FORCE | XFS_LOG_SYNC);
+ }
+
+ } else {
+ xfs_trans_t *tp;
+
+ /*
+ * O_SYNC or O_DSYNC _with_ a size update are handled
+ * the same way.
+ *
+ * If the write was synchronous then we need to make
+ * sure that the inode modification time is permanent.
+ * We'll have updated the timestamp above, so here
+ * we use a synchronous transaction to log the inode.
+ * It's not fast, but it's necessary.
+ *
+ * If this a dsync write and the size got changed
+ * non-transactionally, then we need to ensure that
+ * the size change gets logged in a synchronous
+ * transaction.
+ */
+ tp = xfs_trans_alloc(mp, XFS_TRANS_WRITE_SYNC);
+ if ((error = xfs_trans_reserve(tp, 0,
+ XFS_SWRITE_LOG_RES(mp),
+ 0, 0, 0))) {
+ /* Transaction reserve failed */
+ xfs_trans_cancel(tp, 0);
+ } else {
+ /* Transaction reserve successful */
+ xfs_ilock(ip, XFS_ILOCK_EXCL);
+ xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
+ xfs_trans_ihold(tp, ip);
+ xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
+ xfs_trans_set_sync(tp);
+ error = xfs_trans_commit(tp, 0, NULL);
+ xfs_iunlock(ip, XFS_ILOCK_EXCL);
+ }
+ }
+
+ return error;
+}
+
+/*
* Force a shutdown of the filesystem instantly while keeping
* the filesystem consistent. We don't do an unmount here; just shutdown
* the shop, make sure that absolutely nothing persistent happens to