On Wed, Feb 27, 2013 at 10:17:04AM +1100, Stephen Rothwell wrote: > Hi Mark, > > On Tue, 26 Feb 2013 11:54:56 +0000 Mark Jackson <[email protected]> wrote: > > > > Just tested the current next-20130226 on a custom AM335X board, and I > > received the JFFS2 deadlock shown below. > > Is this new today? is it reproducible? Does if ail for Linus' tree? > > Al, could this be something to do with the new stuff in the vfs tree?
Very unlikely. jffs2_readdir() does, indeed, grab ->sem on the inode in question and then calls the callback (which might fault, grabbing ->mmap_sem). Had been doing that all along. And if the userland area we are doing getdents(2) into had been mmapped from jffs2 file, jffs2_readpage() would be called, which would grab ->sem on the inode of file mmaped in there. Again, that had been going on all along. Unlike the situation with ->i_mutex, this one is probably a false positive - ->sem on directories nests outside of ->mmap_sem, ->sem on non-directories - inside. But that false positive shouldn't be something new; hell, both paths are present in 2.6.12 with the lock orders as in the current tree (except that ->sem used to be a semaphore instead of a mutex). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
