Messages in this thread | | | Date | Mon, 06 Jul 2009 14:24:32 +0800 | From | Amerigo Wang <> | Subject | Re: [Patch] btrfs: use file_remove_suid() after i_mutex is held |
| |
Arjan van de Ven wrote: > On Mon, 6 Jul 2009 01:29:14 -0400 > Amerigo Wang <amwang@redhat.com> wrote: > > >> 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> >> >> --- >> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c >> index 7c3cd24..cd36301 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; >> >> + mutex_lock(&inode->i_mutex); >> + >> err = file_remove_suid(file); >> if (err) >> - goto out_nolock; >> + goto out; >> file_update_time(file); >> >> pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); >> + if (!pages) >> + goto out; >> >> > Hi, > > I don't think you can keep this at GFP_KERNEL once you hold i_mutex.... > very likely this needs to now turn into GFP_NOFS! >
Good point! Hmm, GFP_KERNEL adds __GFP_FS while GFP_NOFS not... Just moving that kmalloc() up, before mutex_lock(), I think, can solve this.
I will update this patch now...
Thanks!
| |