From e64be33ccaceaca67c84237dff8805b861398eab Mon Sep 17 00:00:00 2001 From: Ian Kent Date: Wed, 23 Jul 2008 21:30:20 -0700 Subject: [PATCH] autofs4: check kernel communication pipe is valid for write 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 Signed-off-by: Linus Torvalds --- fs/autofs4/waitq.c | 16 ++++++++++++++-- 1 file changed, 14 insertions(+), 2 deletions(-) diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c index 1132cc2a03..dd2914d7ad 100644 --- a/fs/autofs4/waitq.c +++ b/fs/autofs4/waitq.c @@ -99,6 +99,7 @@ static void autofs4_notify_daemon(struct autofs_sb_info *sbi, 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 autofs_sb_info *sbi, 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, -- 2.39.5