--- /dev/null
+/* -*- 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;
+ }
+
+ mutex_lock(&OCFS2_I(inode)->ip_io_mutex);
+
+ 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);
+ }
+
+ mutex_unlock(&OCFS2_I(inode)->ip_io_mutex);
+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=(%llu), nr=(%d), flags=%d, inode=%p)\n",
+ (unsigned long long)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)
+ mutex_lock(&OCFS2_I(inode)->ip_io_mutex);
+ for (i = 0 ; i < nr ; i++) {
+ if (bhs[i] == NULL) {
+ bhs[i] = sb_getblk(sb, block++);
+ if (bhs[i] == NULL) {
+ if (inode)
+ mutex_unlock(&OCFS2_I(inode)->ip_io_mutex);
+ 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 %llu not uptodate\n",
+ (unsigned long long)bh->b_blocknr,
+ (unsigned long long)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)
+ mutex_unlock(&OCFS2_I(inode)->ip_io_mutex);
+
+ mlog(ML_BH_IO, "block=(%llu), nr=(%d), cached=%s\n",
+ (unsigned long long)block, nr,
+ (!(flags & OCFS2_BH_CACHED) || ignore_cache) ? "no" : "yes");
+
+bail:
+
+ mlog_exit(status);
+ return status;
+}
git://git.onelab.eu / linux-2.6.git / blobdiff