From: Chris Mason <mason@suse.com>
reiserfs_file_write() can use stale metadata after a schedule.
Two reiserfs_file_write bugs, where items can change during a schedule.
---
25-akpm/fs/reiserfs/file.c | 12 ++++++++----
1 files changed, 8 insertions(+), 4 deletions(-)
diff -puN fs/reiserfs/file.c~reiserfs-write-sched-bug fs/reiserfs/file.c
--- 25/fs/reiserfs/file.c~reiserfs-write-sched-bug 2004-03-12 18:25:31.045937680 -0800
+++ 25-akpm/fs/reiserfs/file.c 2004-03-12 18:25:31.048937224 -0800
@@ -365,7 +365,7 @@ int reiserfs_allocate_blocks_for_region(
// it means there are no existing in-tree representation for file area
// we are going to overwrite, so there is nothing to scan through for holes.
for ( curr_block = 0, itempos = path.pos_in_item ; curr_block < blocks_to_allocate && res == POSITION_FOUND ; ) {
-
+retry:
if ( itempos >= ih_item_len(ih)/UNFM_P_SIZE ) {
/* We run out of data in this indirect item, let's look for another
one. */
@@ -422,8 +422,8 @@ int reiserfs_allocate_blocks_for_region(
bh=get_last_bh(&path);
ih=get_ih(&path);
item = get_item(&path);
- // Itempos is still the same
- continue;
+ itempos = path.pos_in_item;
+ goto retry;
}
modifying_this_item = 1;
}
@@ -856,8 +856,12 @@ int reiserfs_prepare_file_region_for_wri
/* Try to find next item */
res = search_for_position_by_key(inode->i_sb, &key, &path);
/* Abort if no more items */
- if ( res != POSITION_FOUND )
+ if ( res != POSITION_FOUND ) {
+ /* make sure later loops don't use this item */
+ itembuf = NULL;
+ item = NULL;
break;
+ }
/* Update information about current indirect item */
itembuf = get_last_bh( &path );
_