From: Jakub Jermar <jermar@itbs.cz>
I found out that BFS filesystem will eventually try to read and interpret
garbage past the end of directory in bfs_add_entry(). If the garbage
(interpreted as i-node number) is not set to zero (does it have to be?)
bfs_add_entry() will consider it a regular directory entry.
This causes weird things like this:
# touch a
# rm a
# ls
# touch b
# ls
a
My patch detects an attempt to read past the end of directory and explicitly
clears the garbage that represents i-node number. Thus the correct behaviour
is achieved.
---
25-akpm/fs/bfs/dir.c | 7 ++++++-
1 files changed, 6 insertions(+), 1 deletion(-)
diff -puN fs/bfs/dir.c~bfs-filesystem-read-past-the-end-of-dir fs/bfs/dir.c
--- 25/fs/bfs/dir.c~bfs-filesystem-read-past-the-end-of-dir Tue May 4 18:05:28 2004
+++ 25-akpm/fs/bfs/dir.c Tue May 4 18:05:28 2004
@@ -274,7 +274,7 @@ static int bfs_add_entry(struct inode *
{
struct buffer_head * bh;
struct bfs_dirent * de;
- int block, sblock, eblock, off;
+ int block, sblock, eblock, off, eoff;
int i;
dprintf("name=%s, namelen=%d\n", name, namelen);
@@ -286,12 +286,17 @@ static int bfs_add_entry(struct inode *
sblock = BFS_I(dir)->i_sblock;
eblock = BFS_I(dir)->i_eblock;
+ eoff = dir->i_size % BFS_BSIZE;
for (block=sblock; block<=eblock; block++) {
bh = sb_bread(dir->i_sb, block);
if(!bh)
return -ENOSPC;
for (off=0; off<BFS_BSIZE; off+=BFS_DIRENT_SIZE) {
de = (struct bfs_dirent *)(bh->b_data + off);
+ if (block==eblock && off>=eoff) {
+ /* Do not read/interpret the garbage in the end of eblock. */
+ de->ino = 0;
+ }
if (!de->ino) {
if ((block-sblock)*BFS_BSIZE + off >= dir->i_size) {
dir->i_size += BFS_DIRENT_SIZE;
_