On Fri, 2016-06-10 at 19:07 +0200, Laurent Dufour wrote: > The 'commit e9a7c2f1a548 ("autofs4: coding style fixes")' removed the > check done on the __vfs_write()'s returned value in autofs4_write(). > This may lead to a spinning process which can't catch any signal. Yeah, sorry my bad. > > Call stack showed in xmon could be : > [c0000003a76c7500] c00000000030df74 __vfs_write+0x134/0x1c0 > (unreliable) > [c0000003a76c75a0] d0000000052a35d4 autofs4_notify_daemon+0x174/0x3f0 > [autofs4] > [c0000003a76c7780] d0000000052a3fa0 autofs4_wait+0x750/0xa10 [autofs4] > [c0000003a76c78b0] d0000000052a24d8 autofs4_mount_wait+0x78/0x140 > [autofs4] > [c0000003a76c7930] d0000000052a2f48 autofs4_d_automount+0x1d8/0x370 > [autofs4] > [c0000003a76c79c0] c0000000003221e4 follow_managed+0x204/0x3a0 > [c0000003a76c7a20] c000000000322c10 lookup_fast+0x220/0x420 > [c0000003a76c7a90] c00000000032324c walk_component+0x5c/0x3e0 > [c0000003a76c7b00] c000000000323794 link_path_walk+0x1c4/0x5f0 > [c0000003a76c7b90] c000000000324b00 path_openat+0xf0/0x1620 > [c0000003a76c7c90] c000000000327f6c do_filp_open+0xfc/0x170 > [c0000003a76c7dc0] c00000000030d06c do_sys_open+0x1bc/0x2e0 > [c0000003a76c7e30] c000000000009260 system_call+0x38/0x108 > --- Exception: c01 (System Call) at 00003fffa38a0988 > > Cc: Ian Kent <raven@xxxxxxxxxx> > Cc: autofs@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > Cc: stable@xxxxxxxxxxxxxxx > Reviewed-by: Greg Kurz <groug@xxxxxxxx> > Signed-off-by: Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx> > Fixes: e9a7c2f1a548 ("autofs4: coding style fixes") > --- > fs/autofs4/waitq.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c > index 0146d911f468..106d94139281 100644 > --- a/fs/autofs4/waitq.c > +++ b/fs/autofs4/waitq.c > @@ -66,11 +66,12 @@ static int autofs4_write(struct autofs_sb_info *sbi, > set_fs(KERNEL_DS); > > mutex_lock(&sbi->pipe_mutex); > - wr = __vfs_write(file, data, bytes, &file->f_pos); > - while (bytes && wr) { Right but why not just wr >= 0 here. I guess this patch probably saves a few bytes. I'll add it to the series. > + while (bytes) { > + wr = __vfs_write(file, data, bytes, &file->f_pos); > + if (wr < 0) > + break; > data += wr; > bytes -= wr; > - wr = __vfs_write(file, data, bytes, &file->f_pos); > } > mutex_unlock(&sbi->pipe_mutex); > -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html