From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 24 Sep 2000 22:43:03 +0100 From: "Stephen C. Tweedie" Subject: Re: [patch] vmfixes-2.4.0-test9-B2 Message-ID: <20000924224303.C2615@redhat.com> References: <20000924231240.D5571@athlon.random> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: ; from mingo@elte.hu on Sun, Sep 24, 2000 at 11:12:39PM +0200 Sender: owner-linux-mm@kvack.org Return-Path: To: Ingo Molnar Cc: Andrea Arcangeli , Linus Torvalds , Rik van Riel , Roger Larsson , MM mailing list , linux-kernel@vger.kernel.org, Stephen Tweedie List-ID: Hi, On Sun, Sep 24, 2000 at 11:12:39PM +0200, Ingo Molnar wrote: > > > ext2_new_block (or whatever that runs getblk with the superlock lock > > acquired)->getblk->GFP->shrink_dcache_memory->prune_dcache-> > > prune_one_dentry->dput->dentry_iput->iput->inode->i_sb->s_op-> > > put_inode->ext2_discard_prealloc->ext2_free_blocks->lock_super->D > > nasty indeed, sigh. Shouldnt ext2_new_block drop the superblock lock in > places where we might block? That's only a valid fix if there are no other filesystems, and no other places in ext2, where we can call GFP with locks which prevent a put_inode from being incurred. And with the quota case to consider, you have to avoid calling GFP with a lock against quota file writes too (and since quota writes may GFP, this would deadlock if there was any form of serialisation on the quota file). This feels like rather a lot of new and interesting deadlocks to be introducing so late in 2.4. :-) Cheers, Stephen -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux.eu.org/Linux-MM/