1 files changed, 643 insertions, 0 deletions

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
new file mode 100644
index 000000000000..8f4467a930a5
--- /dev/null
+++ b/fs/ocfs2/aops.c
@@ -0,0 +1,643 @@
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * 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/slab.h>
+#include <linux/highmem.h>
+#include <linux/pagemap.h>
+#include <asm/byteorder.h>
+
+#define MLOG_MASK_PREFIX ML_FILE_IO
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+
+#include "alloc.h"
+#include "aops.h"
+#include "dlmglue.h"
+#include "extent_map.h"
+#include "file.h"
+#include "inode.h"
+#include "journal.h"
+#include "super.h"
+#include "symlink.h"
+
+#include "buffer_head_io.h"
+
+static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
+				   struct buffer_head *bh_result, int create)
+{
+	int err = -EIO;
+	int status;
+	struct ocfs2_dinode *fe = NULL;
+	struct buffer_head *bh = NULL;
+	struct buffer_head *buffer_cache_bh = NULL;
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	void *kaddr;
+
+	mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
+		   (unsigned long long)iblock, bh_result, create);
+
+	BUG_ON(ocfs2_inode_is_fast_symlink(inode));
+
+	if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
+		mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
+		     (unsigned long long)iblock);
+		goto bail;
+	}
+
+	status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
+				  OCFS2_I(inode)->ip_blkno,
+				  &bh, OCFS2_BH_CACHED, inode);
+	if (status < 0) {
+		mlog_errno(status);
+		goto bail;
+	}
+	fe = (struct ocfs2_dinode *) bh->b_data;
+
+	if (!OCFS2_IS_VALID_DINODE(fe)) {
+		mlog(ML_ERROR, "Invalid dinode #%"MLFu64": signature = %.*s\n",
+		     fe->i_blkno, 7, fe->i_signature);
+		goto bail;
+	}
+
+	if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
+						    le32_to_cpu(fe->i_clusters))) {
+		mlog(ML_ERROR, "block offset is outside the allocated size: "
+		     "%llu\n", (unsigned long long)iblock);
+		goto bail;
+	}
+
+	/* We don't use the page cache to create symlink data, so if
+	 * need be, copy it over from the buffer cache. */
+	if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
+		u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
+			    iblock;
+		buffer_cache_bh = sb_getblk(osb->sb, blkno);
+		if (!buffer_cache_bh) {
+			mlog(ML_ERROR, "couldn't getblock for symlink!\n");
+			goto bail;
+		}
+
+		/* we haven't locked out transactions, so a commit
+		 * could've happened. Since we've got a reference on
+		 * the bh, even if it commits while we're doing the
+		 * copy, the data is still good. */
+		if (buffer_jbd(buffer_cache_bh)
+		    && ocfs2_inode_is_new(inode)) {
+			kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
+			if (!kaddr) {
+				mlog(ML_ERROR, "couldn't kmap!\n");
+				goto bail;
+			}
+			memcpy(kaddr + (bh_result->b_size * iblock),
+			       buffer_cache_bh->b_data,
+			       bh_result->b_size);
+			kunmap_atomic(kaddr, KM_USER0);
+			set_buffer_uptodate(bh_result);
+		}
+		brelse(buffer_cache_bh);
+	}
+
+	map_bh(bh_result, inode->i_sb,
+	       le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);
+
+	err = 0;
+
+bail:
+	if (bh)
+		brelse(bh);
+
+	mlog_exit(err);
+	return err;
+}
+
+static int ocfs2_get_block(struct inode *inode, sector_t iblock,
+			   struct buffer_head *bh_result, int create)
+{
+	int err = 0;
+	u64 p_blkno, past_eof;
+
+	mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
+		   (unsigned long long)iblock, bh_result, create);
+
+	if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
+		mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
+		     inode, inode->i_ino);
+
+	if (S_ISLNK(inode->i_mode)) {
+		/* this always does I/O for some reason. */
+		err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
+		goto bail;
+	}
+
+	/* this can happen if another node truncs after our extend! */
+	spin_lock(&OCFS2_I(inode)->ip_lock);
+	if (iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
+					       OCFS2_I(inode)->ip_clusters))
+		err = -EIO;
+	spin_unlock(&OCFS2_I(inode)->ip_lock);
+	if (err)
+		goto bail;
+
+	err = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
+					  NULL);
+	if (err) {
+		mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
+		     "%"MLFu64", NULL)\n", err, inode,
+		     (unsigned long long)iblock, p_blkno);
+		goto bail;
+	}
+
+	map_bh(bh_result, inode->i_sb, p_blkno);
+
+	if (bh_result->b_blocknr == 0) {
+		err = -EIO;
+		mlog(ML_ERROR, "iblock = %llu p_blkno = %"MLFu64" "
+		     "blkno=(%"MLFu64")\n", (unsigned long long)iblock,
+		     p_blkno, OCFS2_I(inode)->ip_blkno);
+	}
+
+	past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
+	mlog(0, "Inode %lu, past_eof = %"MLFu64"\n", inode->i_ino, past_eof);
+
+	if (create && (iblock >= past_eof))
+		set_buffer_new(bh_result);
+
+bail:
+	if (err < 0)
+		err = -EIO;
+
+	mlog_exit(err);
+	return err;
+}
+
+static int ocfs2_readpage(struct file *file, struct page *page)
+{
+	struct inode *inode = page->mapping->host;
+	loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
+	int ret, unlock = 1;
+
+	mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));
+
+	ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page);
+	if (ret != 0) {
+		if (ret == AOP_TRUNCATED_PAGE)
+			unlock = 0;
+		mlog_errno(ret);
+		goto out;
+	}
+
+	down_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+	/*
+	 * i_size might have just been updated as we grabed the meta lock.  We
+	 * might now be discovering a truncate that hit on another node.
+	 * block_read_full_page->get_block freaks out if it is asked to read
+	 * beyond the end of a file, so we check here.  Callers
+	 * (generic_file_read, fault->nopage) are clever enough to check i_size
+	 * and notice that the page they just read isn't needed.
+	 *
+	 * XXX sys_readahead() seems to get that wrong?
+	 */
+	if (start >= i_size_read(inode)) {
+		char *addr = kmap(page);
+		memset(addr, 0, PAGE_SIZE);
+		flush_dcache_page(page);
+		kunmap(page);
+		SetPageUptodate(page);
+		ret = 0;
+		goto out_alloc;
+	}
+
+	ret = ocfs2_data_lock_with_page(inode, 0, page);
+	if (ret != 0) {
+		if (ret == AOP_TRUNCATED_PAGE)
+			unlock = 0;
+		mlog_errno(ret);
+		goto out_alloc;
+	}
+
+	ret = block_read_full_page(page, ocfs2_get_block);
+	unlock = 0;
+
+	ocfs2_data_unlock(inode, 0);
+out_alloc:
+	up_read(&OCFS2_I(inode)->ip_alloc_sem);
+	ocfs2_meta_unlock(inode, 0);
+out:
+	if (unlock)
+		unlock_page(page);
+	mlog_exit(ret);
+	return ret;
+}
+
+/* Note: Because we don't support holes, our allocation has
+ * already happened (allocation writes zeros to the file data)
+ * so we don't have to worry about ordered writes in
+ * ocfs2_writepage.
+ *
+ * ->writepage is called during the process of invalidating the page cache
+ * during blocked lock processing.  It can't block on any cluster locks
+ * to during block mapping.  It's relying on the fact that the block
+ * mapping can't have disappeared under the dirty pages that it is
+ * being asked to write back.
+ */
+static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
+{
+	int ret;
+
+	mlog_entry("(0x%p)\n", page);
+
+	ret = block_write_full_page(page, ocfs2_get_block, wbc);
+
+	mlog_exit(ret);
+
+	return ret;
+}
+
+/*
+ * ocfs2_prepare_write() can be an outer-most ocfs2 call when it is called
+ * from loopback.  It must be able to perform its own locking around
+ * ocfs2_get_block().
+ */
+int ocfs2_prepare_write(struct file *file, struct page *page,
+			unsigned from, unsigned to)
+{
+	struct inode *inode = page->mapping->host;
+	int ret;
+
+	mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
+
+	ret = ocfs2_meta_lock_with_page(inode, NULL, NULL, 0, page);
+	if (ret != 0) {
+		mlog_errno(ret);
+		goto out;
+	}
+
+	down_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+	ret = block_prepare_write(page, from, to, ocfs2_get_block);
+
+	up_read(&OCFS2_I(inode)->ip_alloc_sem);
+
+	ocfs2_meta_unlock(inode, 0);
+out:
+	mlog_exit(ret);
+	return ret;
+}
+
+/* Taken from ext3. We don't necessarily need the full blown
+ * functionality yet, but IMHO it's better to cut and paste the whole
+ * thing so we can avoid introducing our own bugs (and easily pick up
+ * their fixes when they happen) --Mark */
+static int walk_page_buffers(	handle_t *handle,
+				struct buffer_head *head,
+				unsigned from,
+				unsigned to,
+				int *partial,
+				int (*fn)(	handle_t *handle,
+						struct buffer_head *bh))
+{
+	struct buffer_head *bh;
+	unsigned block_start, block_end;
+	unsigned blocksize = head->b_size;
+	int err, ret = 0;
+	struct buffer_head *next;
+
+	for (	bh = head, block_start = 0;
+		ret == 0 && (bh != head || !block_start);
+	    	block_start = block_end, bh = next)
+	{
+		next = bh->b_this_page;
+		block_end = block_start + blocksize;
+		if (block_end <= from || block_start >= to) {
+			if (partial && !buffer_uptodate(bh))
+				*partial = 1;
+			continue;
+		}
+		err = (*fn)(handle, bh);
+		if (!ret)
+			ret = err;
+	}
+	return ret;
+}
+
+struct ocfs2_journal_handle *ocfs2_start_walk_page_trans(struct inode *inode,
+							 struct page *page,
+							 unsigned from,
+							 unsigned to)
+{
+	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+	struct ocfs2_journal_handle *handle = NULL;
+	int ret = 0;
+
+	handle = ocfs2_start_trans(osb, NULL, OCFS2_INODE_UPDATE_CREDITS);
+	if (!handle) {
+		ret = -ENOMEM;
+		mlog_errno(ret);
+		goto out;
+	}
+
+	if (ocfs2_should_order_data(inode)) {
+		ret = walk_page_buffers(handle->k_handle,
+					page_buffers(page),
+					from, to, NULL,
+					ocfs2_journal_dirty_data);
+		if (ret < 0) 
+			mlog_errno(ret);
+	}
+out:
+	if (ret) {
+		if (handle)
+			ocfs2_commit_trans(handle);
+		handle = ERR_PTR(ret);
+	}
+	return handle;
+}
+
+static int ocfs2_commit_write(struct file *file, struct page *page,
+			      unsigned from, unsigned to)
+{
+	int ret, extending = 0, locklevel = 0;
+	loff_t new_i_size;
+	struct buffer_head *di_bh = NULL;
+	struct inode *inode = page->mapping->host;
+	struct ocfs2_journal_handle *handle = NULL;
+
+	mlog_entry("(0x%p, 0x%p, %u, %u)\n", file, page, from, to);
+
+	/* NOTE: ocfs2_file_aio_write has ensured that it's safe for
+	 * us to sample inode->i_size here without the metadata lock:
+	 *
+	 * 1) We're currently holding the inode alloc lock, so no
+	 *    nodes can change it underneath us.
+	 *
+	 * 2) We've had to take the metadata lock at least once
+	 *    already to check for extending writes, hence insuring
+	 *    that our current copy is also up to date.
+	 */
+	new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
+	if (new_i_size > i_size_read(inode)) {
+		extending = 1;
+		locklevel = 1;
+	}
+
+	ret = ocfs2_meta_lock_with_page(inode, NULL, &di_bh, locklevel, page);
+	if (ret != 0) {
+		mlog_errno(ret);
+		goto out;
+	}
+
+	ret = ocfs2_data_lock_with_page(inode, 1, page);
+	if (ret != 0) {
+		mlog_errno(ret);
+		goto out_unlock_meta;
+	}
+
+	if (extending) {
+		handle = ocfs2_start_walk_page_trans(inode, page, from, to);
+		if (IS_ERR(handle)) {
+			ret = PTR_ERR(handle);
+			handle = NULL;
+			goto out_unlock_data;
+		}
+
+		/* Mark our buffer early. We'd rather catch this error up here
+		 * as opposed to after a successful commit_write which would
+		 * require us to set back inode->i_size. */
+		ret = ocfs2_journal_access(handle, inode, di_bh,
+					   OCFS2_JOURNAL_ACCESS_WRITE);
+		if (ret < 0) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+	}
+
+	/* might update i_size */
+	ret = generic_commit_write(file, page, from, to);
+	if (ret < 0) {
+		mlog_errno(ret);
+		goto out_commit;
+	}
+
+	if (extending) {
+		loff_t size = (u64) i_size_read(inode);
+		struct ocfs2_dinode *di =
+			(struct ocfs2_dinode *)di_bh->b_data;
+
+		/* ocfs2_mark_inode_dirty is too heavy to use here. */
+		inode->i_blocks = ocfs2_align_bytes_to_sectors(size);
+		inode->i_ctime = inode->i_mtime = CURRENT_TIME;
+
+		di->i_size = cpu_to_le64(size);
+		di->i_ctime = di->i_mtime = 
+				cpu_to_le64(inode->i_mtime.tv_sec);
+		di->i_ctime_nsec = di->i_mtime_nsec = 
+				cpu_to_le32(inode->i_mtime.tv_nsec);
+
+		ret = ocfs2_journal_dirty(handle, di_bh);
+		if (ret < 0) {
+			mlog_errno(ret);
+			goto out_commit;
+		}
+	}
+
+	BUG_ON(extending && (i_size_read(inode) != new_i_size));
+
+out_commit:
+	if (handle)
+		ocfs2_commit_trans(handle);
+out_unlock_data:
+	ocfs2_data_unlock(inode, 1);
+out_unlock_meta:
+	ocfs2_meta_unlock(inode, locklevel);
+out:
+	if (di_bh)
+		brelse(di_bh);
+
+	mlog_exit(ret);
+	return ret;
+}
+
+static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
+{
+	sector_t status;
+	u64 p_blkno = 0;
+	int err = 0;
+	struct inode *inode = mapping->host;
+
+	mlog_entry("(block = %llu)\n", (unsigned long long)block);
+
+	/* We don't need to lock journal system files, since they aren't
+	 * accessed concurrently from multiple nodes.
+	 */
+	if (!INODE_JOURNAL(inode)) {
+		err = ocfs2_meta_lock(inode, NULL, NULL, 0);
+		if (err) {
+			if (err != -ENOENT)
+				mlog_errno(err);
+			goto bail;
+		}
+		down_read(&OCFS2_I(inode)->ip_alloc_sem);
+	}
+
+	err = ocfs2_extent_map_get_blocks(inode, block, 1, &p_blkno,
+					  NULL);
+
+	if (!INODE_JOURNAL(inode)) {
+		up_read(&OCFS2_I(inode)->ip_alloc_sem);
+		ocfs2_meta_unlock(inode, 0);
+	}
+
+	if (err) {
+		mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
+		     (unsigned long long)block);
+		mlog_errno(err);
+		goto bail;
+	}
+
+
+bail:
+	status = err ? 0 : p_blkno;
+
+	mlog_exit((int)status);
+
+	return status;
+}
+
+/*
+ * TODO: Make this into a generic get_blocks function.
+ *
+ * From do_direct_io in direct-io.c:
+ *  "So what we do is to permit the ->get_blocks function to populate
+ *   bh.b_size with the size of IO which is permitted at this offset and
+ *   this i_blkbits."
+ *
+ * This function is called directly from get_more_blocks in direct-io.c.
+ *
+ * called like this: dio->get_blocks(dio->inode, fs_startblk,
+ * 					fs_count, map_bh, dio->rw == WRITE);
+ */
+static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
+				     unsigned long max_blocks,
+				     struct buffer_head *bh_result, int create)
+{
+	int ret;
+	u64 vbo_max; /* file offset, max_blocks from iblock */
+	u64 p_blkno;
+	int contig_blocks;
+	unsigned char blocksize_bits;
+
+	if (!inode || !bh_result) {
+		mlog(ML_ERROR, "inode or bh_result is null\n");
+		return -EIO;
+	}
+
+	blocksize_bits = inode->i_sb->s_blocksize_bits;
+
+	/* This function won't even be called if the request isn't all
+	 * nicely aligned and of the right size, so there's no need
+	 * for us to check any of that. */
+
+	vbo_max = ((u64)iblock + max_blocks) << blocksize_bits;
+
+	spin_lock(&OCFS2_I(inode)->ip_lock);
+	if ((iblock + max_blocks) >
+	    ocfs2_clusters_to_blocks(inode->i_sb,
+				     OCFS2_I(inode)->ip_clusters)) {
+		spin_unlock(&OCFS2_I(inode)->ip_lock);
+		ret = -EIO;
+		goto bail;
+	}
+	spin_unlock(&OCFS2_I(inode)->ip_lock);
+
+	/* This figures out the size of the next contiguous block, and
+	 * our logical offset */
+	ret = ocfs2_extent_map_get_blocks(inode, iblock, 1, &p_blkno,
+					  &contig_blocks);
+	if (ret) {
+		mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
+		     (unsigned long long)iblock);
+		ret = -EIO;
+		goto bail;
+	}
+
+	map_bh(bh_result, inode->i_sb, p_blkno);
+
+	/* make sure we don't map more than max_blocks blocks here as
+	   that's all the kernel will handle at this point. */
+	if (max_blocks < contig_blocks)
+		contig_blocks = max_blocks;
+	bh_result->b_size = contig_blocks << blocksize_bits;
+bail:
+	return ret;
+}
+
+/* 
+ * ocfs2_dio_end_io is called by the dio core when a dio is finished.  We're
+ * particularly interested in the aio/dio case.  Like the core uses
+ * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
+ * truncation on another.
+ */
+static void ocfs2_dio_end_io(struct kiocb *iocb,
+			     loff_t offset,
+			     ssize_t bytes,
+			     void *private)
+{
+	struct inode *inode = iocb->ki_filp->f_dentry->d_inode;
+
+	/* this io's submitter should not have unlocked this before we could */
+	BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
+	ocfs2_iocb_clear_rw_locked(iocb);
+	up_read(&inode->i_alloc_sem);
+	ocfs2_rw_unlock(inode, 0);
+}
+
+static ssize_t ocfs2_direct_IO(int rw,
+			       struct kiocb *iocb,
+			       const struct iovec *iov,
+			       loff_t offset,
+			       unsigned long nr_segs)
+{
+	struct file *file = iocb->ki_filp;
+	struct inode *inode = file->f_dentry->d_inode->i_mapping->host;
+	int ret;
+
+	mlog_entry_void();
+	ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
+					    inode->i_sb->s_bdev, iov, offset,
+					    nr_segs, 
+					    ocfs2_direct_IO_get_blocks,
+					    ocfs2_dio_end_io);
+	mlog_exit(ret);
+	return ret;
+}
+
+struct address_space_operations ocfs2_aops = {
+	.readpage	= ocfs2_readpage,
+	.writepage	= ocfs2_writepage,
+	.prepare_write	= ocfs2_prepare_write,
+	.commit_write	= ocfs2_commit_write,
+	.bmap		= ocfs2_bmap,
+	.sync_page	= block_sync_page,
+	.direct_IO	= ocfs2_direct_IO
+};