diff options
| author | Lai Siyao <lai.siyao@intel.com> | 2016-09-18 16:37:57 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-09-19 09:44:03 +0200 |
| commit | 17be217056561b90134384d863abfd543d2321e4 (patch) | |
| tree | a829ad58acad44c9b03650afae714ff021d2a5db /drivers/staging/lustre/lustre/llite | |
| parent | 6535a7d046a24d7d426a9dfedf918eac954ea00c (diff) | |
staging: lustre: statahead: race in start/stop statahead
When starting statahead thread, it should check whether current
lli_opendir_key was deauthorized in the mean time by another
process.
Signed-off-by: Lai Siyao <lai.siyao@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-3270
Reviewed-on: http://review.whamcloud.com/9666
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/lustre/lustre/llite')
| -rw-r--r-- | drivers/staging/lustre/lustre/llite/statahead.c | 29 |
1 files changed, 25 insertions, 4 deletions
diff --git a/drivers/staging/lustre/lustre/llite/statahead.c b/drivers/staging/lustre/lustre/llite/statahead.c index 92972d09d6e1..8cc0bfaf32d3 100644 --- a/drivers/staging/lustre/lustre/llite/statahead.c +++ b/drivers/staging/lustre/lustre/llite/statahead.c @@ -1509,7 +1509,24 @@ static int start_statahead_thread(struct inode *dir, struct dentry *dentry) CDEBUG(D_READA, "start statahead thread: sai %p, parent %pd\n", sai, parent); + /* + * if another process started statahead thread, or deauthorized current + * lli_opendir_key, don't start statahead. + */ + spin_lock(&lli->lli_sa_lock); + if (unlikely(lli->lli_sai || lli->lli_opendir_key || + lli->lli_opendir_pid != current->pid)) { + spin_unlock(&lli->lli_sa_lock); + + dput(parent); + iput(sai->sai_inode); + rc = -EAGAIN; + goto out; + } lli->lli_sai = sai; + spin_unlock(&lli->lli_sa_lock); + + atomic_inc(&ll_i2sbi(parent->d_inode)->ll_sa_running); task = kthread_run(ll_statahead_thread, parent, "ll_sa_%u", lli->lli_opendir_pid); @@ -1518,9 +1535,12 @@ static int start_statahead_thread(struct inode *dir, struct dentry *dentry) rc = PTR_ERR(task); CERROR("cannot start ll_sa thread: rc = %d\n", rc); dput(parent); - lli->lli_opendir_key = NULL; + + spin_lock(&lli->lli_sa_lock); thread_set_flags(thread, SVC_STOPPED); thread_set_flags(&sai->sai_agl_thread, SVC_STOPPED); + spin_unlock(&lli->lli_sa_lock); + ll_sai_put(sai); LASSERT(!lli->lli_sai); return -EAGAIN; @@ -1529,7 +1549,6 @@ static int start_statahead_thread(struct inode *dir, struct dentry *dentry) l_wait_event(thread->t_ctl_waitq, thread_is_running(thread) || thread_is_stopped(thread), &lwi); - atomic_inc(&ll_i2sbi(d_inode(parent))->ll_sa_running); ll_sai_put(sai); /* @@ -1540,9 +1559,11 @@ static int start_statahead_thread(struct inode *dir, struct dentry *dentry) out: kfree(sai); + /* + * once we start statahead thread failed, disable statahead so + * subsequent won't waste time to try it. + */ spin_lock(&lli->lli_sa_lock); - lli->lli_opendir_key = NULL; - lli->lli_opendir_pid = 0; lli->lli_sa_enabled = 0; spin_unlock(&lli->lli_sa_lock); |