[patch-2.4.0-test10-pre3] bugfix for BFS

From: Tigran Aivazian (tigran@veritas.com)
Date: Mon Oct 16 2000 - 06:08:35 EST


Hi Linus,

I just noticed that BFS did not update the number of free blocks correctly
on extending the file (in some circumstances) so after running bonnie on
BFS (although showing it's a lot faster than ext2! :) one could see some
very strange numbers in df(1) output. The patch below fixes this bug (also
updates my email address, while I was there).

Regards,
Tigran

diff -urN -X dontdiff linux/fs/bfs/dir.c bfs/fs/bfs/dir.c
--- linux/fs/bfs/dir.c Tue Sep 5 22:07:29 2000
+++ bfs/fs/bfs/dir.c Sun Oct 15 23:31:06 2000
@@ -1,7 +1,7 @@
 /*
  * fs/bfs/dir.c
  * BFS directory operations.
- * Copyright (C) 1999 Tigran Aivazian <tigran@ocston.org>
+ * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>
  */
 
 #include <linux/sched.h>
diff -urN -X dontdiff linux/fs/bfs/file.c bfs/fs/bfs/file.c
--- linux/fs/bfs/file.c Tue Sep 5 22:07:29 2000
+++ bfs/fs/bfs/file.c Mon Oct 16 12:04:47 2000
@@ -1,7 +1,7 @@
 /*
  * fs/bfs/file.c
  * BFS file operations.
- * Copyright (C) 1999 Tigran Aivazian <tigran@ocston.org>
+ * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>
  */
 
 #include <linux/fs.h>
@@ -26,7 +26,7 @@
 
 static int bfs_move_block(unsigned long from, unsigned long to, kdev_t dev)
 {
- struct buffer_head *bh, *new = NULL;
+ struct buffer_head *bh, *new;
 
         bh = bread(dev, from, BFS_BSIZE);
         if (!bh)
@@ -56,11 +56,12 @@
 static int bfs_get_block(struct inode * inode, long block,
         struct buffer_head * bh_result, int create)
 {
- long phys, next_free_block;
+ long phys;
         int err;
- struct super_block *s = inode->i_sb;
+ struct super_block *sb = inode->i_sb;
+ struct buffer_head *sbh = sb->su_sbh;
 
- if (block < 0 || block > s->su_blocks)
+ if (block < 0 || block > sb->su_blocks)
                 return -EIO;
 
         phys = inode->iu_sblock + block;
@@ -90,24 +91,25 @@
 
         /* if the last data block for this file is the last allocated block, we can
            extend the file trivially, without moving it anywhere */
- if (inode->iu_eblock == s->su_lf_eblk) {
+ if (inode->iu_eblock == sb->su_lf_eblk) {
                 dprintf("c=%d, b=%08lx, phys=%08lx (simple extension)\n",
                                 create, block, phys);
                 bh_result->b_dev = inode->i_dev;
                 bh_result->b_blocknr = phys;
                 bh_result->b_state |= (1UL << BH_Mapped);
- s->su_lf_eblk = inode->iu_eblock = inode->iu_sblock + block;
+ sb->su_freeb -= phys - inode->iu_eblock;
+ sb->su_lf_eblk = inode->iu_eblock = phys;
                 mark_inode_dirty(inode);
- mark_buffer_dirty(s->su_sbh);
+ mark_buffer_dirty(sbh);
                 err = 0;
                 goto out;
         }
 
         /* Ok, we have to move this entire file to the next free block */
- next_free_block = s->su_lf_eblk + 1;
+ phys = sb->su_lf_eblk + 1;
         if (inode->iu_sblock) { /* if data starts on block 0 then there is no data */
                 err = bfs_move_blocks(inode->i_dev, inode->iu_sblock,
- inode->iu_eblock, next_free_block);
+ inode->iu_eblock, phys);
                 if (err) {
                         dprintf("failed to move ino=%08lx -> fs corruption\n", inode->i_ino);
                         goto out;
@@ -115,12 +117,18 @@
         } else
                 err = 0;
 
- inode->iu_sblock = next_free_block;
- s->su_lf_eblk = inode->iu_eblock = next_free_block + block;
+ dprintf("c=%d, b=%08lx, phys=%08lx (moved)\n", create, block, phys);
+ inode->iu_sblock = phys;
+ phys += block;
+ sb->su_lf_eblk = inode->iu_eblock = phys;
+
+ /* this assumes nothing can write the inode back while we are here
+ * and thus update inode->i_blocks! (XXX)*/
+ sb->su_freeb -= inode->iu_eblock - inode->iu_sblock + 1 - inode->i_blocks;
         mark_inode_dirty(inode);
- mark_buffer_dirty(s->su_sbh);
+ mark_buffer_dirty(sbh);
         bh_result->b_dev = inode->i_dev;
- bh_result->b_blocknr = inode->iu_sblock + block;
+ bh_result->b_blocknr = phys;
         bh_result->b_state |= (1UL << BH_Mapped);
 out:
         unlock_kernel();
@@ -153,8 +161,7 @@
         sync_page: block_sync_page,
         prepare_write: bfs_prepare_write,
         commit_write: generic_commit_write,
- bmap: bfs_bmap
+ bmap: bfs_bmap,
 };
 
-struct inode_operations bfs_file_inops = {
-};
+struct inode_operations bfs_file_inops;
diff -urN -X dontdiff linux/fs/bfs/inode.c bfs/fs/bfs/inode.c
--- linux/fs/bfs/inode.c Sun Sep 17 17:51:57 2000
+++ bfs/fs/bfs/inode.c Sun Oct 15 23:30:37 2000
@@ -1,7 +1,7 @@
 /*
  * fs/bfs/inode.c
  * BFS superblock and inode operations.
- * Copyright (C) 1999 Tigran Aivazian <tigran@veritas.com>
+ * Copyright (C) 1999,2000 Tigran Aivazian <tigran@veritas.com>
  * From fs/minix, Copyright (C) 1991, 1992 Linus Torvalds.
  */
 
@@ -325,7 +325,7 @@
         return NULL;
 }
 
-static DECLARE_FSTYPE_DEV( bfs_fs_type, "bfs", bfs_read_super);
+static DECLARE_FSTYPE_DEV(bfs_fs_type, "bfs", bfs_read_super);
 
 static int __init init_bfs_fs(void)
 {

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This archive was generated by hypermail 2b29 : Mon Oct 23 2000 - 21:00:08 EST