Messages in this thread | | | Date | Mon, 06 Jul 2009 15:42:51 +0800 | From | Tao Ma <> | Subject | Re: [Patch v2] btrfs: use file_remove_suid() after i_mutex is held |
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Hi Amerigo,
Amerigo Wang wrote: > V1 -> V2: > Move kmalloc() before mutex_lock(), suggested by Arjan. > > file_remove_suid() should be called with i_mutex held, > file_update_time() too. So move them after mutex_lock(). > > Plus, check the return value of kmalloc(). > > Signed-off-by: WANG Cong <amwang@redhat.com> > Cc: Arjan <arjan@infradead.org> > Cc: Chris Mason <chris.mason@oracle.com> > Cc: Yan Zheng <zheng.yan@oracle.com> > Cc: Sven Wegener <sven.wegener@stealer.net> > Cc: Josef Bacik <jbacik@redhat.com> > Cc: Jeff Mahoney <jeffm@suse.com> > > --- > diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c > index 7c3cd24..09ef5d6 100644 > --- a/fs/btrfs/file.c > +++ b/fs/btrfs/file.c > @@ -944,14 +944,17 @@ static ssize_t btrfs_file_write(struct file *file, const char __user *buf, > if (count == 0) > goto out_nolock; > > + pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); > + if (!pages) > + goto out_nolock; I guess you need to set err to -ENOMEM here so that the caller knows what's wrong. With your patch, this function just return 0(since num_written and err are both 0) with no error, and I guess it is worse than kernel BUG out when the NULL pages is used later.
Regards, Tao
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