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| author | Ian Kent <raven@themaw.net> | 2005-05-01 08:59:16 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-05-01 08:59:16 -0700 |
| commit | 4dcd00b18118d174c4b8d838c11f437f0af3c20c (patch) | |
| tree | 0e7497aa50c383e64f34616819066fc0bfe3c56d /fs/autofs4 | |
| parent | 945b092011c6af71a0107be96e119c8c08776f3f (diff) | |
| download | lwn-4dcd00b18118d174c4b8d838c11f437f0af3c20c.tar.gz lwn-4dcd00b18118d174c4b8d838c11f437f0af3c20c.zip | |
[PATCH] autofs4: wait order fix
It's possible for an event wait request to arive before the event
requestor. If this happens the daemon never gets notified and autofs
hangs.
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'fs/autofs4')
| -rw-r--r-- | fs/autofs4/autofs_i.h | 1 | ||||
| -rw-r--r-- | fs/autofs4/waitq.c | 22 |
2 files changed, 13 insertions, 10 deletions
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h index f5a52c871726..978987735252 100644 --- a/fs/autofs4/autofs_i.h +++ b/fs/autofs4/autofs_i.h @@ -84,6 +84,7 @@ struct autofs_wait_queue { char *name; /* This is for status reporting upon return */ int status; + atomic_t notified; atomic_t wait_ctr; }; diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c index 1ab24a662e09..5a40d36e5a51 100644 --- a/fs/autofs4/waitq.c +++ b/fs/autofs4/waitq.c @@ -210,17 +210,8 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry, wq->len = len; wq->status = -EINTR; /* Status return if interrupted */ atomic_set(&wq->wait_ctr, 2); + atomic_set(&wq->notified, 1); up(&sbi->wq_sem); - - DPRINTK("new wait id = 0x%08lx, name = %.*s, nfy=%d", - (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify); - /* autofs4_notify_daemon() may block */ - if (notify != NFY_NONE) { - autofs4_notify_daemon(sbi,wq, - notify == NFY_MOUNT ? - autofs_ptype_missing : - autofs_ptype_expire_multi); - } } else { atomic_inc(&wq->wait_ctr); up(&sbi->wq_sem); @@ -229,6 +220,17 @@ int autofs4_wait(struct autofs_sb_info *sbi, struct dentry *dentry, (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify); } + if (notify != NFY_NONE && atomic_dec_and_test(&wq->notified)) { + int type = (notify == NFY_MOUNT ? + autofs_ptype_missing : autofs_ptype_expire_multi); + + DPRINTK(("new wait id = 0x%08lx, name = %.*s, nfy=%d\n", + (unsigned long) wq->wait_queue_token, wq->len, wq->name, notify)); + + /* autofs4_notify_daemon() may block */ + autofs4_notify_daemon(sbi, wq, type); + } + /* wq->name is NULL if and only if the lock is already released */ if ( sbi->catatonic ) { |