udf: Fix possible corruption when close races with write

When we close a file, we remove preallocated blocks from it. But this
truncation was not protected by i_mutex and thus it could have raced with a
write through a different fd and cause crashes or even filesystem corruption.

Signed-off-by: Jan Kara <jack@suse.cz>
This commit is contained in:
Jan Kara 2009-08-07 00:27:27 +02:00
parent 81056dd044
commit cbc8cc3352

View file

@ -193,9 +193,11 @@ int udf_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
static int udf_release_file(struct inode *inode, struct file *filp)
{
if (filp->f_mode & FMODE_WRITE) {
mutex_lock(&inode->i_mutex);
lock_kernel();
udf_discard_prealloc(inode);
unlock_kernel();
mutex_unlock(&inode->i_mutex);
}
return 0;
}