From: Ian Kent It is possible for an autofs mount to become catatonic (and for the daemon communication pipe to become NULL) after a wait has been initiallized but before the request has been sent to the daemon. We need to check for this before sending the request packet. Signed-off-by: Ian Kent Signed-off-by: Andrew Morton --- fs/autofs4/waitq.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff -puN fs/autofs4/waitq.c~autofs4-check-kernel-communication-pipe-is-valid-for-write fs/autofs4/waitq.c --- a/fs/autofs4/waitq.c~autofs4-check-kernel-communication-pipe-is-valid-for-write +++ a/fs/autofs4/waitq.c @@ -99,6 +99,7 @@ static void autofs4_notify_daemon(struct union autofs_packet_union v4_pkt; union autofs_v5_packet_union v5_pkt; } pkt; + struct file *pipe = NULL; size_t pktsz; DPRINTK("wait id = 0x%08lx, name = %.*s, type=%d", @@ -164,8 +165,19 @@ static void autofs4_notify_daemon(struct return; } - if (autofs4_write(sbi->pipe, &pkt, pktsz)) - autofs4_catatonic_mode(sbi); + /* Check if we have become catatonic */ + mutex_lock(&sbi->wq_mutex); + if (!sbi->catatonic) { + pipe = sbi->pipe; + get_file(pipe); + } + mutex_unlock(&sbi->wq_mutex); + + if (pipe) { + if (autofs4_write(pipe, &pkt, pktsz)) + autofs4_catatonic_mode(sbi); + fput(pipe); + } } static int autofs4_getpath(struct autofs_sb_info *sbi, _