zte's code,first commit

Change-Id: I9a04da59e459a9bc0d67f101f700d9d7dc8d681b
diff --git a/ap/os/linux/linux-3.4.x/fs/xfs/xfs_rw.c b/ap/os/linux/linux-3.4.x/fs/xfs/xfs_rw.c
new file mode 100644
index 0000000..597d044
--- /dev/null
+++ b/ap/os/linux/linux-3.4.x/fs/xfs/xfs_rw.c
@@ -0,0 +1,156 @@
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_types.h"
+#include "xfs_bit.h"
+#include "xfs_log.h"
+#include "xfs_inum.h"
+#include "xfs_trans.h"
+#include "xfs_sb.h"
+#include "xfs_ag.h"
+#include "xfs_mount.h"
+#include "xfs_bmap_btree.h"
+#include "xfs_dinode.h"
+#include "xfs_inode.h"
+#include "xfs_error.h"
+#include "xfs_rw.h"
+
+/*
+ * 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
+ * this filesystem after this point.
+ */
+void
+xfs_do_force_shutdown(
+	xfs_mount_t	*mp,
+	int		flags,
+	char		*fname,
+	int		lnnum)
+{
+	int		logerror;
+
+	logerror = flags & SHUTDOWN_LOG_IO_ERROR;
+
+	if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
+		xfs_notice(mp,
+	"%s(0x%x) called from line %d of file %s.  Return address = 0x%p",
+			__func__, flags, lnnum, fname, __return_address);
+	}
+	/*
+	 * No need to duplicate efforts.
+	 */
+	if (XFS_FORCED_SHUTDOWN(mp) && !logerror)
+		return;
+
+	/*
+	 * This flags XFS_MOUNT_FS_SHUTDOWN, makes sure that we don't
+	 * queue up anybody new on the log reservations, and wakes up
+	 * everybody who's sleeping on log reservations to tell them
+	 * the bad news.
+	 */
+	if (xfs_log_force_umount(mp, logerror))
+		return;
+
+	if (flags & SHUTDOWN_CORRUPT_INCORE) {
+		xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_CORRUPT,
+    "Corruption of in-memory data detected.  Shutting down filesystem");
+		if (XFS_ERRLEVEL_HIGH <= xfs_error_level)
+			xfs_stack_trace();
+	} else if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
+		if (logerror) {
+			xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_LOGERROR,
+		"Log I/O Error Detected.  Shutting down filesystem");
+		} else if (flags & SHUTDOWN_DEVICE_REQ) {
+			xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_IOERROR,
+		"All device paths lost.  Shutting down filesystem");
+		} else if (!(flags & SHUTDOWN_REMOTE_REQ)) {
+			xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_IOERROR,
+		"I/O Error Detected. Shutting down filesystem");
+		}
+	}
+	if (!(flags & SHUTDOWN_FORCE_UMOUNT)) {
+		xfs_alert(mp,
+	"Please umount the filesystem and rectify the problem(s)");
+	}
+}
+
+/*
+ * This isn't an absolute requirement, but it is
+ * just a good idea to call xfs_read_buf instead of
+ * directly doing a read_buf call. For one, we shouldn't
+ * be doing this disk read if we are in SHUTDOWN state anyway,
+ * so this stops that from happening. Secondly, this does all
+ * the error checking stuff and the brelse if appropriate for
+ * the caller, so the code can be a little leaner.
+ */
+
+int
+xfs_read_buf(
+	struct xfs_mount *mp,
+	xfs_buftarg_t	 *target,
+	xfs_daddr_t	 blkno,
+	int              len,
+	uint             flags,
+	xfs_buf_t	 **bpp)
+{
+	xfs_buf_t	 *bp;
+	int		 error;
+
+	if (!flags)
+		flags = XBF_LOCK | XBF_MAPPED;
+
+	bp = xfs_buf_read(target, blkno, len, flags);
+	if (!bp)
+		return XFS_ERROR(EIO);
+	error = bp->b_error;
+	if (!error && !XFS_FORCED_SHUTDOWN(mp)) {
+		*bpp = bp;
+	} else {
+		*bpp = NULL;
+		if (error) {
+			xfs_buf_ioerror_alert(bp, __func__);
+		} else {
+			error = XFS_ERROR(EIO);
+		}
+		if (bp) {
+			XFS_BUF_UNDONE(bp);
+			xfs_buf_stale(bp);
+			/*
+			 * brelse clears B_ERROR and b_error
+			 */
+			xfs_buf_relse(bp);
+		}
+	}
+	return (error);
+}
+
+/*
+ * helper function to extract extent size hint from inode
+ */
+xfs_extlen_t
+xfs_get_extsz_hint(
+	struct xfs_inode	*ip)
+{
+	if ((ip->i_d.di_flags & XFS_DIFLAG_EXTSIZE) && ip->i_d.di_extsize)
+		return ip->i_d.di_extsize;
+	if (XFS_IS_REALTIME_INODE(ip))
+		return ip->i_mount->m_sb.sb_rextsize;
+	return 0;
+}