Messages in this thread | | | Date | Tue, 17 Oct 2006 08:53:50 -0400 | From | Mike Day <> | Subject | Re: fuse: fix hang on SMP |
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On 16/10/06 16:51 -0700, Andrew Morton wrote: >On Mon, 16 Oct 2006 18:27:10 +0200 >Miklos Szeredi <miklos@szeredi.hu> wrote: > >> Fuse didn't always call i_size_write() with i_mutex held which caused >> rare hangs on SMP/32bit. > >Yes, that is a bit of a trap. I'll maintain a patch in -mm which spits a >warning if i_size_write() is called without i_mutex held. >
>+void i_size_write(struct inode *inode, loff_t i_size) >+{ >+ WARN_ON_ONCE(!mutex_is_locked(&inode->i_mutex));
Miklos' patch would generate this warning because he uses the spinlock inside struct fuse_conn to synchronize the write:
+static void fuse_vmtruncate(struct inode *inode, loff_t offset) +{ + struct fuse_conn *fc = get_fuse_conn(inode); + int need_trunc; + + spin_lock(&fc->lock); + need_trunc = inode->i_size > offset; + i_size_write(inode, offset); + spin_unlock(&fc->lock);
-- Mike D. Day IBM LTC Cell: 919 412-3900 Sametime: ncmike@us.ibm.com AIM: ncmikeday Yahoo: ultra.runner PGP key: http://www.ncultra.org/ncmike/pubkey.asc [unhandled content-type:application/pgp-signature] | |