From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758260Ab0GBJpJ (ORCPT ); Fri, 2 Jul 2010 05:45:09 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:62327 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752742Ab0GBJpG (ORCPT ); Fri, 2 Jul 2010 05:45:06 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=date:from:to:cc:subject:message-id:mime-version:content-type :content-disposition:user-agent; b=nQb5HEizdjg+S9l0K+G6dkduFbhoR+IJ7IWBpBMgKJytmid33bmHR6K1E9HUDbmj/7 R3mD68m11OYC+Dvfv9RiRtiEV0oeouM1bc2SJdPhX4ktZ8Hbq6jPU/NltS7d5CmjnoR3 DgB4RdUxaXQ5bd+YadHjbUPYdiEb5NRWWTkjY= Date: Fri, 2 Jul 2010 12:49:16 +0300 From: Sergey Senozhatsky To: Frederic Weisbecker Cc: Jan Kara , Christoph Hellwig , Andrew Morton , reiserfs-devel@vger.kernel.org, linux-kernel@vger.kernel.org Subject: reiserfs locking (v2) Message-ID: <20100702094916.GA5103@swordfish.minsk.epam.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="rwEMma7ioTxnRzrJ" Content-Disposition: inline User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --rwEMma7ioTxnRzrJ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Crap, I forgot to munmap. Sorry. fixed =3D=3D=3D code =3D=3D=3D /* 2010, Sergey Senozhatsky. GPLv2 Description: We have several PIDs working with conftest.mmap. Actually this is (seems) what hapenning during emacs configure. traced emacs configure: vfork() ... =3D=3D=3D=3D =2E.. PID 5446 5446 open("conftest.mmap", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0600) =3D 3 write(3, "g\306isQ\377J\354)\315\272\253\362\373\343F|\302T\370\33\350\347\215vZ.c3\= 237\311\232"...,=20 4096) =3D 4096 close(3) =3D 0 open("conftest.txt", O_RDWR|O_CREAT|O_TRUNC|O_LARGEFILE, 0600) =3D 3 write(3, "\0", 1) =3D 1 mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) =3D 0xb78a8000 close(3) =3D 0 munmap(0xb78a8000, 4096) =3D 0 open("conftest.mmap", O_RDWR|O_LARGEFILE) =3D 3 mmap2(0xb78a8000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED, =20 3, 0) =3D 0xb78a8000 read(3, "*****"...,=20 4096) =3D 4096 close(3) =3D 0 open(".", O_RDONLY|O_LARGEFILE) =3D 3 close(3) =3D 0 fstatat64(AT_FDCWD, "conftest.mmap", {st_mode=3DS_IFREG|0600, st_size=3D4096, ...}, AT_SYMLINK_NOFOLLOW) =3D 0 unlinkat(AT_FDCWD, "conftest.mmap", 0) =3D 0 =3D=3D=3D=3D =2E.. PID 5449 5449 fstatat64(AT_FDCWD, "conftest.mmap", {st_mode=3DS_IFREG|0600, st_size= =3D4096, ...}, AT_SYMLINK_NOFOLLOW) =3D 0 5449 unlinkat(AT_FDCWD, "conftest.mmap", 0) =3D 0 5449 execve("/bin/rm", ["rm", "-f", "conftest.mmap", "conftest.txt"] =2E. */ /* The code below produces: [ 46.727489] =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D [ 46.727495] [ INFO: possible circular locking dependency detected ] [ 46.727499] 2.6.35-rc3-dbg-git5-00446-g36336bc-dirty #64 [ 46.727503] ------------------------------------------------------- [ 46.727506] a.out/5840 is trying to acquire lock: [ 46.727510] (&sb->s_type->i_mutex_key#10){+.+.+.}, at: [] rei= serfs_file_release+0x12b/0x367 [ 46.727526]=20 [ 46.727527] but task is already holding lock: [ 46.727530] (&mm->mmap_sem){++++++}, at: [] sys_mmap_pgoff+0x= a4/0xe7 [ 46.727540]=20 [ 46.727541] which lock already depends on the new lock. [ 46.727543]=20 [ 46.727546]=20 [ 46.727546] the existing dependency chain (in reverse order) is: [ 46.727550]=20 [ 46.727551] -> #1 (&mm->mmap_sem){++++++}: [ 46.727557] [] lock_acquire+0x59/0x70 [ 46.727565] [] might_fault+0x53/0x70 [ 46.727571] [] copy_to_user+0x30/0x48 [ 46.727578] [] filldir64+0x95/0xc9 [ 46.727584] [] reiserfs_readdir_dentry+0x35d/0x4d9 [ 46.727590] [] reiserfs_readdir+0x12/0x17 [ 46.727596] [] vfs_readdir+0x6d/0x92 [ 46.727600] [] sys_getdents64+0x63/0xa2 [ 46.727606] [] sysenter_do_call+0x12/0x32 [ 46.727612]=20 [ 46.727613] -> #0 (&sb->s_type->i_mutex_key#10){+.+.+.}: [ 46.727621] [] __lock_acquire+0x96d/0xbe1 [ 46.727626] [] lock_acquire+0x59/0x70 [ 46.727632] [] __mutex_lock_common+0x39/0x36b [ 46.727639] [] mutex_lock_nested+0x12/0x15 [ 46.727644] [] reiserfs_file_release+0x12b/0x367 [ 46.727650] [] fput+0xe0/0x16a [ 46.727657] [] remove_vma+0x28/0x47 [ 46.727662] [] do_munmap+0x1e8/0x200 [ 46.727667] [] mmap_region+0x6b/0x372 [ 46.727672] [] do_mmap_pgoff+0x23c/0x282 [ 46.727678] [] sys_mmap_pgoff+0xbd/0xe7 [ 46.727683] [] sysenter_do_call+0x12/0x32 [ 46.727689]=20 [ 46.727690] other info that might help us debug this: [ 46.727691]=20 [ 46.727695] 1 lock held by a.out/5840: [ 46.727698] #0: (&mm->mmap_sem){++++++}, at: [] sys_mmap_pgo= ff+0xa4/0xe7 [ 46.727707]=20 [ 46.727708] stack backtrace: [ 46.727713] Pid: 5840, comm: a.out Not tainted 2.6.35-rc3-dbg-git5-00446= -g36336bc-dirty #64 [ 46.727717] Call Trace: [ 46.727722] [] ? printk+0xf/0x11 [ 46.727728] [] print_circular_bug+0x8a/0x96 [ 46.727734] [] __lock_acquire+0x96d/0xbe1 [ 46.727740] [] ? look_up_lock_class+0x6c/0x7b [ 46.727746] [] ? mark_lock+0x26/0x1b3 [ 46.727752] [] lock_acquire+0x59/0x70 [ 46.727758] [] ? reiserfs_file_release+0x12b/0x367 [ 46.727764] [] __mutex_lock_common+0x39/0x36b [ 46.727769] [] ? reiserfs_file_release+0x12b/0x367 [ 46.727775] [] mutex_lock_nested+0x12/0x15 [ 46.727781] [] ? reiserfs_file_release+0x12b/0x367 [ 46.727786] [] reiserfs_file_release+0x12b/0x367 [ 46.727792] [] ? free_pgd_range+0x96/0x12f [ 46.727798] [] ? fput+0x90/0x16a [ 46.727803] [] fput+0xe0/0x16a [ 46.727808] [] remove_vma+0x28/0x47 [ 46.727814] [] ? arch_unmap_area_topdown+0x0/0x18 [ 46.727819] [] do_munmap+0x1e8/0x200 [ 46.727825] [] mmap_region+0x6b/0x372 [ 46.727831] [] do_mmap_pgoff+0x23c/0x282 [ 46.727837] [] sys_mmap_pgoff+0xbd/0xe7 [ 46.727842] [] sysenter_do_call+0x12/0x32 =20 */ #define _GNU_SOURCE #include #include #include #include #include #include int main() { char buf[4096]; int i =3D 0; /* we don't really care */ for (; i < 4096; i++) buf[i] =3D (i + 65) % 255; for (i =3D 0; i < 10; i++) { int pid =3D fork(); if (pid > 0 ) { printf("parent..."); } else if (pid =3D=3D 0) { =09 printf("child...\n"); int fd =3D open("conftest.mmap", O_WRONLY|O_CREAT|O_TRUNC|O_LARGEFILE, 0= 600); if (fd > 0) { printf("OPEN ok %d\n", fd); if (write(fd, buf, 4096) < 0) printf("WRITE error\n"); else printf("WRITE ok\n"); =09 close(fd); } else { printf("OPEN error\n"); } =09 fd =3D open("conftest.mmap", O_RDWR|O_LARGEFILE); if (fd > 0) { printf("OPEN conftest.mmap %d\n", fd); =09 void *map =3D mmap((void*)0xb78a8000, 4096, PROT_READ|PROT_WRITE, MAP_P= RIVATE|MAP_FIXED, fd, 0); if (map =3D=3D MAP_FAILED) { printf("MMAP failed\n"); goto out; } else { printf("MMAP ok\n"); } =09 if (read(fd, buf, 4096) < 0) printf("READ failed\n"); else printf("READ ok\n"); close(fd); munmap(map, 4096); } else { printf("Error: can't open conftest.mmap\n"); } =09 out: fd =3D open(".", O_RDONLY|O_LARGEFILE); if (fd > 0) { printf("OPEN . ok %d... closing\n", fd); close(fd); } else { printf("OPEN error\n"); } =09 struct stat _stat; if (fstatat(AT_FDCWD, "conftest.mmap", &_stat, AT_SYMLINK_NOFOLLOW) < 0) printf("FSTATAT error\n"); else printf("FSTATAT ok\n"); =09 if (unlinkat(AT_FDCWD, "conftest.mmap", 0) < 0) printf("UNLINKAT error\n"); else printf("UNLINKAT ok\n"); } else { printf("FORK error\n"); } } =09 return 0; } --rwEMma7ioTxnRzrJ Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iJwEAQECAAYFAkwtthwACgkQfKHnntdSXjTD2QP+MsiS9JtHMnHKbt9tYYKKAhSJ /eUIfTFHhfxZlCb6+EMDyccjQimFWHS6IiiqoaiLiO+ahvJ7j4EDP6bLTWavK4D5 r7a3mmSoE/3BXCi9+1umzvtM1FINPp+JmvZ+BanL+Kde49yg5exq/e8j0OyUF5hu deMPjfb38TM1sM7X6IM= =jgSf -----END PGP SIGNATURE----- --rwEMma7ioTxnRzrJ--