Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761615AbcJ1QT1 (ORCPT ); Fri, 28 Oct 2016 12:19:27 -0400 Received: from mout02.posteo.de ([185.67.36.142]:41883 "EHLO mout02.posteo.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756196AbcJ1QTY (ORCPT ); Fri, 28 Oct 2016 12:19:24 -0400 Message-ID: <1477671544.8927.1.camel@embedded.rocks> Subject: Re: [PATCH] ubifs: Fix regression in ubifs_readdir() From: =?ISO-8859-1?Q?J=F6rg?= Krause To: Richard Weinberger , linux-mtd@lists.infradead.org Cc: dedekind1@gmail.com, linux-kernel@vger.kernel.org, stable@vger.kernel.org, adrian.hunter@intel.com, ralph.sennhauser@gmail.com, peda@axentia.se Date: Fri, 28 Oct 2016 18:19:04 +0200 In-Reply-To: <1477648432-9543-1-git-send-email-richard@nod.at> References: <1477648432-9543-1-git-send-email-richard@nod.at> Organization: Embedded Rocks Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.22.2 Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 7155 Lines: 179 Hi, On Fri, 2016-10-28 at 11:53 +0200, Richard Weinberger wrote: > Commit c83ed4c9dbb35 ("ubifs: Abort readdir upon error") broke > overlayfs support because the fix exposed an internal error > code to VFS. > > Reported-by: Peter Rosin > Tested-by: Peter Rosin > Reported-by: Ralph Sennhauser > Fixes: c83ed4c9dbb35 ("ubifs: Abort readdir upon error") > Cc: stable@vger.kernel.org > Signed-off-by: Richard Weinberger > --- >  fs/ubifs/dir.c | 8 ++++++++ >  1 file changed, 8 insertions(+) > > diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c > index bd4a5e8ce441..ca16c5d7bab1 100644 > --- a/fs/ubifs/dir.c > +++ b/fs/ubifs/dir.c > @@ -543,6 +543,14 @@ static int ubifs_readdir(struct file *file, > struct dir_context *ctx) >   >   if (err != -ENOENT) >   ubifs_err(c, "cannot find next direntry, error %d", > err); > + else > + /* > +  * -ENOENT is a non-fatal error in this context, the > TNC uses > +  * it to indicate that the cursor moved past the > current directory > +  * and readdir() has to stop. > +  */ > + err = 0; > + >   >   /* 2 is a special value indicating that there are no more > direntries */ >   ctx->pos = 2; I'm not sure if it's related to the issue reported by Peter Rosin and Ralph Sennhauser, but I am still getting a kernel panic using UBIFS with OverlayFS on Linux v4.9.0-rc2 with this patch applied: """ [    2.709197] ubi0: default fastmap pool size: 15 [    2.713806] ubi0: default fastmap WL pool size: 7 [    2.718776] ubi0: attaching mtd5 [    3.690342] ubi0: scanning is finished [    3.726232] ubi0 warning: ubi_eba_init: cannot reserve enough PEBs for bad PEB handling, reserved 18, need 20 [    3.756003] ubi0: attached mtd5 (name "ubi-0", size 44 MiB) [    3.761658] ubi0: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes [    3.768857] ubi0: min./max. I/O unit sizes: 2048/2048, sub-page size 2048 [    3.775860] ubi0: VID header offset: 2048 (aligned 2048), data offset: 4096 [    3.782886] ubi0: good PEBs: 352, bad PEBs: 0, corrupted PEBs: 0 [    3.789080] ubi0: user volume: 1, internal volumes: 1, max. volumes count: 128 [    3.796501] ubi0: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 955660178 [    3.805742] ubi0: available PEBs: 0, total reserved PEBs: 352, PEBs reserved for bad PEB handling: 18 [    3.815502] ubi0: background thread "ubi_bgt0d" started, PID 40 [    3.822173] ubi1: default fastmap pool size: 10 [    3.827213] ubi1: default fastmap WL pool size: 5 [    3.832016] ubi1: attaching mtd7 [    4.278806] ubi1: scanning is finished [    4.376526] ubi1: volume 0 ("user") re-sized from 13 to 162 LEBs [    4.391959] ubi1: attached mtd7 (name "data", size 36 MiB) [    4.397813] ubi1: PEB size: 131072 bytes (128 KiB), LEB size: 126976 bytes [    4.404761] ubi1: min./max. I/O unit sizes: 2048/2048, sub-page size 2048 [    4.411752] ubi1: VID header offset: 2048 (aligned 2048), data offset: 4096 [    4.418909] ubi1: good PEBs: 288, bad PEBs: 0, corrupted PEBs: 0 [    4.425107] ubi1: user volume: 2, internal volumes: 1, max. volumes count: 128 [    4.432399] ubi1: max/mean erase counter: 1/0, WL threshold: 4096, image sequence number: 1961582752 [    4.441714] ubi1: available PEBs: 0, total reserved PEBs: 288, PEBs reserved for bad PEB handling: 20 [    4.451267] ubi1: background thread "ubi_bgt1d" started, PID 41 [    4.469335] input: gpio-keys as /devices/soc0/gpio-keys/input/input0 [    4.492732] stmp3xxx-rtc 80056000.rtc: setting system clock to 1970- 01-01 00:01:07 UTC (67) [    4.506810] ALSA device list: [    4.509854]   #0: mxs_wm8524 [    4.523140] uart-pl011 80074000.serial: no DMA platform data [    4.909981] UBIFS (ubi0:1): UBIFS: mounted UBI device 0, volume 1, name "rootfs", R/O mode [    4.919428] UBIFS (ubi0:1): LEB size: 126976 bytes (124 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes [    4.933097] UBIFS (ubi0:1): FS size: 40378368 bytes (38 MiB, 318 LEBs), journal size 5586944 bytes (5 MiB, 44 LEBs) [    4.944659] UBIFS (ubi0:1): reserved for root: 0 bytes (0 KiB) [    4.954275] UBIFS (ubi0:1): media format: w4/r0 (latest is w4/r0), UUID 3F29D9B8-363D-4A54-8CE4-BF6969BB9687, small LPT model [    4.993543] VFS: Mounted root (ubifs filesystem) readonly on device 0:13. [    5.023313] devtmpfs: mounted [    5.036855] Freeing unused kernel memory: 144K (c0506000 - c052a000) [    5.043278] This architecture does not have kernel memory protection. [    5.869112] UBIFS (ubi1:0): background thread "ubifs_bgt1_0" started, PID 43 [    6.056630] UBIFS (ubi1:0): start fixing up free space [    6.162648] UBIFS (ubi1:0): free space fixup complete [    6.263554] UBIFS (ubi1:0): UBIFS: mounted UBI device 1, volume 0, name "user" [    6.271600] UBIFS (ubi1:0): LEB size: 126976 bytes (124 KiB), min./max. I/O unit sizes: 2048 bytes/2048 bytes [    6.285552] UBIFS (ubi1:0): FS size: 19300352 bytes (18 MiB, 152 LEBs), journal size 3047424 bytes (2 MiB, 24 LEBs) [    6.296731] UBIFS (ubi1:0): reserved for root: 0 bytes (0 KiB) [    6.306432] UBIFS (ubi1:0): media format: w4/r0 (latest is w4/r0), UUID A5813F13-6645-4096-B663-A08D87959541, small LPT model [    6.542487] random: crng init done mount: mounting overlay on /mnt/overlay failed: No such file or directory mount: mounting /dev on /mnt/overlay/dev failed: No such file or directory mount: mounting /mnt/user on /mnt/overlay/mnt/user failed: No such file or directory chroot: can't execute '/sbin/init': No such file or directory [    6.670206] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00007f00 [    6.670206]  [    6.679426] CPU: 0 PID: 1 Comm: chroot Not tainted 4.9.0-rc2-LINTECH #1 [    6.686075] Hardware name: Freescale MXS (Device Tree) [    6.691320] [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [    6.699143] [] (show_stack) from [] (panic+0xb4/0x23c) [    6.706098] [] (panic) from [] (do_exit+0x450/0x84c) [    6.712866] [] (do_exit) from [] (do_group_exit+0xb8/0xbc) [    6.720150] [] (do_group_exit) from [] (SyS_exit_group+0x10/0x14) [    6.728037] [] (SyS_exit_group) from [] (ret_fast_syscall+0x0/0x1c) [    6.736155] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00007f00 """ This is my preinit script: """ #!/bin/sh mount -t ubifs /dev/ubi1_0 /mnt/user mkdir -p /mnt/user/overlay mkdir -p /mnt/user/work # Overlay read-only rootfs and read-write user filesystem. mount -t overlay overlay -o lowerdir=/,upperdir=/mnt/user/overlay,workdir=/mnt/user/work,noatime /mnt/overlay # Move necessary mount points mount -n --move /dev /mnt/overlay/dev mount -n --move /mnt/user /mnt/overlay/mnt/user exec chroot /mnt/overlay /sbin/init """ Note, this is working on Linux 4.7. Best regards Jörg Krause