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| author | Ian Kent <raven@themaw.net> | 2008-07-23 21:30:20 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-07-24 10:47:32 -0700 |
| commit | e64be33ccaceaca67c84237dff8805b861398eab (patch) | |
| tree | 574c0eed196ac6115e0f042c1e4564d1b85474d2 | |
| parent | f4c7da02615bebcaf89f15a8d055922f515160b8 (diff) | |
| download | lwn-e64be33ccaceaca67c84237dff8805b861398eab.tar.gz lwn-e64be33ccaceaca67c84237dff8805b861398eab.zip | |
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 <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/autofs4/waitq.c | 16 |
1 files changed, 14 insertions, 2 deletions
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c index 1132cc2a0310..dd2914d7ad7f 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, |