diff options
Diffstat (limited to 'fs/ocfs2/buffer_head_io.c')
| -rw-r--r-- | fs/ocfs2/buffer_head_io.c | 232 |
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 00000000000..d424041b38e --- /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; +} |