[PATCH] OCFS2: The Second Oracle Cluster Filesystem

The OCFS2 file system module.

Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>

1 files changed, 232 insertions, 0 deletions

diff --git a/fs/ocfs2/buffer_head_io.c b/fs/ocfs2/buffer_head_io.c
new file mode 100644
index 000000000000..d424041b38e9
--- /dev/null
+++ b/fs/ocfs2/buffer_head_io.c
@@ -0,0 +1,232 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * io.c
+ *
+ * Buffer cache handling
+ *
+ * Copyright (C) 2002, 2004 Oracle.  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; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will 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 to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/fs.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "alloc.h"
+#include "inode.h"
+#include "journal.h"
+#include "uptodate.h"
+
+#include "buffer_head_io.h"
+
+int ocfs2_write_block(struct ocfs2_super *osb, struct buffer_head *bh,
+                      struct inode *inode)
+{
+        int ret = 0;
+
+        mlog_entry("(bh->b_blocknr = %llu, inode=%p)\n",
+                   (unsigned long long)bh->b_blocknr, inode);
+
+        BUG_ON(bh->b_blocknr < OCFS2_SUPER_BLOCK_BLKNO);
+        BUG_ON(buffer_jbd(bh));
+
+        /* No need to check for a soft readonly file system here. non
+         * journalled writes are only ever done on system files which
+         * can get modified during recovery even if read-only. */
+        if (ocfs2_is_hard_readonly(osb)) {
+                ret = -EROFS;
+                goto out;
+        }
+
+        down(&OCFS2_I(inode)->ip_io_sem);
+
+        lock_buffer(bh);
+        set_buffer_uptodate(bh);
+
+        /* remove from dirty list before I/O. */
+        clear_buffer_dirty(bh);
+
+        get_bh(bh); /* for end_buffer_write_sync() */                   
+        bh->b_end_io = end_buffer_write_sync;
+        submit_bh(WRITE, bh);
+
+        wait_on_buffer(bh);
+
+        if (buffer_uptodate(bh)) {
+                ocfs2_set_buffer_uptodate(inode, bh);
+        } else {
+                /* We don't need to remove the clustered uptodate
+                 * information for this bh as it's not marked locally
+                 * uptodate. */
+                ret = -EIO;
+                brelse(bh);
+        }
+
+        up(&OCFS2_I(inode)->ip_io_sem);
+out:
+        mlog_exit(ret);
+        return ret;
+}
+
+int ocfs2_read_blocks(struct ocfs2_super *osb, u64 block, int nr,
+                      struct buffer_head *bhs[], int flags,
+                      struct inode *inode)
+{
+        int status = 0;
+        struct super_block *sb;
+        int i, ignore_cache = 0;
+        struct buffer_head *bh;
+
+        mlog_entry("(block=(%"MLFu64"), nr=(%d), flags=%d, inode=%p)\n",
+                   block, nr, flags, inode);
+
+        if (osb == NULL || osb->sb == NULL || bhs == NULL) {
+                status = -EINVAL;
+                mlog_errno(status);
+                goto bail;
+        }
+
+        if (nr < 0) {
+                mlog(ML_ERROR, "asked to read %d blocks!\n", nr);
+                status = -EINVAL;
+                mlog_errno(status);
+                goto bail;
+        }
+
+        if (nr == 0) {
+                mlog(ML_BH_IO, "No buffers will be read!\n");
+                status = 0;
+                goto bail;
+        }
+
+        sb = osb->sb;
+
+        if (flags & OCFS2_BH_CACHED && !inode)
+                flags &= ~OCFS2_BH_CACHED;
+
+        if (inode)
+                down(&OCFS2_I(inode)->ip_io_sem);
+        for (i = 0 ; i < nr ; i++) {
+                if (bhs[i] == NULL) {
+                        bhs[i] = sb_getblk(sb, block++);
+                        if (bhs[i] == NULL) {
+                                if (inode)
+                                        up(&OCFS2_I(inode)->ip_io_sem);
+                                status = -EIO;
+                                mlog_errno(status);
+                                goto bail;
+                        }
+                }
+                bh = bhs[i];
+                ignore_cache = 0;
+
+                if (flags & OCFS2_BH_CACHED &&
+                    !ocfs2_buffer_uptodate(inode, bh)) {
+                        mlog(ML_UPTODATE,
+                             "bh (%llu), inode %"MLFu64" not uptodate\n",
+                             (unsigned long long)bh->b_blocknr,
+                             OCFS2_I(inode)->ip_blkno);
+                        ignore_cache = 1;
+                }
+
+                /* XXX: Can we ever get this and *not* have the cached
+                 * flag set? */
+                if (buffer_jbd(bh)) {
+                        if (!(flags & OCFS2_BH_CACHED) || ignore_cache)
+                                mlog(ML_BH_IO, "trying to sync read a jbd "
+                                               "managed bh (blocknr = %llu)\n",
+                                     (unsigned long long)bh->b_blocknr);
+                        continue;
+                }
+
+                if (!(flags & OCFS2_BH_CACHED) || ignore_cache) {
+                        if (buffer_dirty(bh)) {
+                                /* This should probably be a BUG, or
+                                 * at least return an error. */
+                                mlog(ML_BH_IO, "asking me to sync read a dirty "
+                                               "buffer! (blocknr = %llu)\n",
+                                     (unsigned long long)bh->b_blocknr);
+                                continue;
+                        }
+
+                        lock_buffer(bh);
+                        if (buffer_jbd(bh)) {
+#ifdef CATCH_BH_JBD_RACES
+                                mlog(ML_ERROR, "block %llu had the JBD bit set "
+                                               "while I was in lock_buffer!",
+                                     (unsigned long long)bh->b_blocknr);
+                                BUG();
+#else
+                                unlock_buffer(bh);
+                                continue;
+#endif
+                        }
+                        clear_buffer_uptodate(bh);
+                        get_bh(bh); /* for end_buffer_read_sync() */
+                        bh->b_end_io = end_buffer_read_sync;
+                        if (flags & OCFS2_BH_READAHEAD)
+                                submit_bh(READA, bh);
+                        else
+                                submit_bh(READ, bh);
+                        continue;
+                }
+        }
+
+        status = 0;
+
+        for (i = (nr - 1); i >= 0; i--) {
+                bh = bhs[i];
+
+                /* We know this can't have changed as we hold the
+                 * inode sem. Avoid doing any work on the bh if the
+                 * journal has it. */
+                if (!buffer_jbd(bh))
+                        wait_on_buffer(bh);
+
+                if (!buffer_uptodate(bh)) {
+                        /* Status won't be cleared from here on out,
+                         * so we can safely record this and loop back
+                         * to cleanup the other buffers. Don't need to
+                         * remove the clustered uptodate information
+                         * for this bh as it's not marked locally
+                         * uptodate. */
+                        status = -EIO;
+                        brelse(bh);
+                        bhs[i] = NULL;
+                        continue;
+                }
+
+                if (inode)
+                        ocfs2_set_buffer_uptodate(inode, bh);
+        }
+        if (inode)
+                up(&OCFS2_I(inode)->ip_io_sem);
+
+        mlog(ML_BH_IO, "block=(%"MLFu64"), nr=(%d), cached=%s\n", block, nr,
+             (!(flags & OCFS2_BH_CACHED) || ignore_cache) ? "no" : "yes");
+
+bail:
+
+        mlog_exit(status);
+        return status;
+}