From: Ian Kent Date: Thu, 24 Jul 2008 04:30:20 +0000 (-0700) Subject: autofs4: check kernel communication pipe is valid for write X-Git-Tag: v2.6.27-rc1~632 X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=e64be33ccaceaca67c84237dff8805b861398eab;p=linux-2.6-omap-h63xx.git 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 --- diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c index 1132cc2a031..dd2914d7ad7 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,