From: Lai Siyao <lai.si...@intel.com> 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.si...@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.y...@intel.com> Reviewed-by: James Simmons <uja.o...@gmail.com> Reviewed-by: Oleg Drokin <oleg.dro...@intel.com> Signed-off-by: James Simmons <jsimm...@infradead.org> --- 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 5be955d..70ca252 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); -- 1.7.1 _______________________________________________ devel mailing list de...@linuxdriverproject.org http://driverdev.linuxdriverproject.org/mailman/listinfo/driverdev-devel
