From 40e56a3d91fa10ae22e9c9287e8db19408c136aa Mon Sep 17 00:00:00 2001
From: nfshp <nfshp>
Date: Wed, 12 Feb 2003 08:57:21 +0000
Subject: [PATCH] initial check-in for SAN support. There's still not clean
 stuff like mount option(data=writeback) of ost.

---
 lustre/extN/extN-san.diff | 88 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 88 insertions(+)
 create mode 100644 lustre/extN/extN-san.diff

diff --git a/lustre/extN/extN-san.diff b/lustre/extN/extN-san.diff
new file mode 100644
index 0000000..c961c3f
--- /dev/null
+++ b/lustre/extN/extN-san.diff
@@ -0,0 +1,88 @@
+--- lustre/extN/inode.orig.c	2002-12-29 18:48:56.000000000 +0800
++++ lustre/extN/inode.c	2002-12-29 19:17:24.000000000 +0800
+@@ -2728,3 +2728,85 @@
+  * here, in extN_aops_journal_start() to ensure that the forthcoming "see if we
+  * need to extend" test in extN_prepare_write() succeeds.  
+  */
++
++/* for each block: 1 ind + 1 dind + 1 tind
++ * for each block: 3 bitmap blocks
++ * for each block: 3 group descriptor blocks
++ * i inode block
++ * 1 superblock
++ * 2 * EXTN_SINGLEDATA_TRANS_BLOCKS for the quote files
++ * ((1+1+1) * 3 * nblocks) + 1 + 1 + 2 * EXTN_SINGLEDATA_TRANS_BLOCKS
++ *
++ * XXX assuming:
++ * (1) fs logic block size == page size
++ * (2) extN in writeback mode
++ */
++static inline int extN_san_write_trans_blocks(int nblocks)
++{
++	int ret;
++	
++	ret = (1 + 1 + 1) * 3 * nblocks + 1 + 1;
++
++#ifdef CONFIG_QUOTA
++	ret += 2 * EXTN_SINGLEDATA_TRANS_BLOCKS;
++#endif
++
++	return ret;
++}
++
++/* Alloc blocks for an inode, while don't create any buffer/page
++ * for data I/O; set the inode size if file is extended.
++ *
++ * @inode:    target inode
++ * @blocks:   array of logic block number
++ * @nblocks:  how many blocks need be alloced
++ * @newsize:  new filesize we should set
++ *
++ * return:    0 success, otherwise failed
++ *            (*blocks) contains physical block number alloced
++ *
++ * XXX this assume the fs block size == page size
++ */
++int extN_prep_san_write(struct inode *inode, long *blocks,
++			int nblocks, loff_t newsize)
++{
++	handle_t *handle;
++	struct buffer_head bh_tmp;
++	int needed_blocks;
++	int i, ret, ret2;
++
++	needed_blocks = extN_san_write_trans_blocks(nblocks);
++
++	lock_kernel();
++	handle = extN_journal_start(inode, needed_blocks);
++	if (IS_ERR(handle)) {
++		unlock_kernel();
++		return PTR_ERR(handle);
++	}
++	unlock_kernel();
++
++	/* alloc blocks one by one */
++	for (i = 0; i < nblocks; i++) {
++		ret = extN_get_block_handle(handle, inode, blocks[i],
++						&bh_tmp, 1);
++		if (ret)
++			break;
++
++		blocks[i] = bh_tmp.b_blocknr;
++	}
++
++	/* set inode size if needed */
++	if (!ret && (newsize > inode->i_size)) {
++		inode->i_size = newsize;
++		extN_mark_inode_dirty(handle, inode);
++	}
++
++	lock_kernel();
++	ret2 = extN_journal_stop(handle, inode);
++	unlock_kernel();
++
++	if (!ret)
++		ret = ret2;
++	return ret;
++}
++EXPORT_SYMBOL(extN_prep_san_write);
-- 
1.8.3.1