fs: block_dump missing dentry locking

I think the block_dump output in __mark_inode_dirty is missing dentry locking.
Surely the i_dentry list can change any time, so we may not even *get* a
dentry there. If we do get one by chance, then it would appear to be able to
go away or get renamed at any time...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Nick Piggin 2009-05-28 09:01:15 +02:00 committed by Al Viro
parent 545b9fd3d7
commit 4195f73d13

View file

@ -64,6 +64,28 @@ static void writeback_release(struct backing_dev_info *bdi)
clear_bit(BDI_pdflush, &bdi->state);
}
static noinline void block_dump___mark_inode_dirty(struct inode *inode)
{
if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev")) {
struct dentry *dentry;
const char *name = "?";
dentry = d_find_alias(inode);
if (dentry) {
spin_lock(&dentry->d_lock);
name = (const char *) dentry->d_name.name;
}
printk(KERN_DEBUG
"%s(%d): dirtied inode %lu (%s) on %s\n",
current->comm, task_pid_nr(current), inode->i_ino,
name, inode->i_sb->s_id);
if (dentry) {
spin_unlock(&dentry->d_lock);
dput(dentry);
}
}
}
/**
* __mark_inode_dirty - internal function
* @inode: inode to mark
@ -114,23 +136,8 @@ void __mark_inode_dirty(struct inode *inode, int flags)
if ((inode->i_state & flags) == flags)
return;
if (unlikely(block_dump)) {
struct dentry *dentry = NULL;
const char *name = "?";
if (!list_empty(&inode->i_dentry)) {
dentry = list_entry(inode->i_dentry.next,
struct dentry, d_alias);
if (dentry && dentry->d_name.name)
name = (const char *) dentry->d_name.name;
}
if (inode->i_ino || strcmp(inode->i_sb->s_id, "bdev"))
printk(KERN_DEBUG
"%s(%d): dirtied inode %lu (%s) on %s\n",
current->comm, task_pid_nr(current), inode->i_ino,
name, inode->i_sb->s_id);
}
if (unlikely(block_dump))
block_dump___mark_inode_dirty(inode);
spin_lock(&inode_lock);
if ((inode->i_state & flags) != flags) {