From: Mingming Cao <cmm@us.ibm.com>
Hnadle null inode->i_sb in the inode teardown paths.
- In lots of places, like generic_forget_inode(), destroy_inode() is
called after clear_inode() is called. It is possible that the filesystem
clear_inode() method could clear the sb pointer.
- clear_inode() checks whether the inode->i_sb is a NULL pointer.
Probably we should do this consistently.
- iput() need a sb NULL pointer check too. diReadSpecial() in
jfs/jfs_imap.c clears the sb pointer before calls iput(). Oops could
happen, although this might be a rare case.
fs/inode.c | 10 +++++-----
1 files changed, 5 insertions(+), 5 deletions(-)
diff -puN fs/inode.c~inode-i_sb-checks fs/inode.c
--- 25/fs/inode.c~inode-i_sb-checks 2003-12-17 23:25:42.000000000 -0800
+++ 25-akpm/fs/inode.c 2003-12-17 23:25:42.000000000 -0800
@@ -160,7 +160,7 @@ void destroy_inode(struct inode *inode)
if (inode_has_buffers(inode))
BUG();
security_inode_free(inode);
- if (inode->i_sb->s_op->destroy_inode)
+ if (inode->i_sb && inode->i_sb->s_op->destroy_inode)
inode->i_sb->s_op->destroy_inode(inode);
else
kmem_cache_free(inode_cachep, (inode));
@@ -1086,13 +1086,13 @@ static inline void iput_final(struct ino
void iput(struct inode *inode)
{
if (inode) {
- struct super_operations *op = inode->i_sb->s_op;
-
+ struct super_block *sb = inode->i_sb;
+
if (inode->i_state == I_CLEAR)
BUG();
- if (op && op->put_inode)
- op->put_inode(inode);
+ if (sb && sb->s_op && sb->s_op->put_inode)
+ sb->s_op->put_inode(inode);
if (atomic_dec_and_lock(&inode->i_count, &inode_lock))
iput_final(inode);
_