From 8366fbd10d6644f87e9332d27d544b231e0e6966 Mon Sep 17 00:00:00 2001
From: fanyong <fanyong>
Date: Thu, 20 Nov 2008 05:51:00 +0000
Subject: [PATCH] Branch HEAD b=16947 i=h.huang i=yury.umanets
Hold lli_lock when access lli_sai to prevent NULL pointer.
---
lustre/llite/file.c | 4 ++--
lustre/llite/llite_internal.h | 18 +++++++--------
lustre/llite/statahead.c | 41 +++++++++++++++++++++--------------
3 files changed, 36 insertions(+), 27 deletions(-)
diff --git a/lustre/llite/file.c b/lustre/llite/file.c
index 35c1d8713e..9850774e44 100644
--- a/lustre/llite/file.c
+++ b/lustre/llite/file.c
@@ -331,7 +331,7 @@ int ll_file_release(struct inode *inode, struct file *file)
* Different processes can open the same dir, "ll_opendir_key" means:
* it is me that should stop the statahead thread. */
if (lli->lli_opendir_key == fd && lli->lli_opendir_pid != 0)
- ll_stop_statahead(inode, fd);
+ ll_stop_statahead(inode, lli->lli_opendir_key);
if (inode->i_sb->s_root == file->f_dentry) {
LUSTRE_FPRIVATE(file) = NULL;
@@ -690,7 +690,7 @@ out_och_free:
up(&lli->lli_och_sem);
out_openerr:
if (opendir_set != 0)
- ll_stop_statahead(inode, fd);
+ ll_stop_statahead(inode, lli->lli_opendir_key);
}
return rc;
diff --git a/lustre/llite/llite_internal.h b/lustre/llite/llite_internal.h
index 22b5981250..a03e1bf82e 100644
--- a/lustre/llite/llite_internal.h
+++ b/lustre/llite/llite_internal.h
@@ -1069,23 +1069,23 @@ struct ll_statahead_info {
};
int do_statahead_enter(struct inode *dir, struct dentry **dentry, int lookup);
-int ll_statahead_exit(struct dentry *dentry, int result);
+void ll_statahead_exit(struct dentry *dentry, int result);
void ll_stop_statahead(struct inode *inode, void *key);
static inline
-int ll_statahead_mark(struct dentry *dentry)
+void ll_statahead_mark(struct dentry *dentry)
{
struct ll_inode_info *lli = ll_i2info(dentry->d_parent->d_inode);
- struct ll_statahead_info *sai = lli->lli_sai;
struct ll_dentry_data *ldd = ll_d2d(dentry);
- int rc = 0;
- if (likely(ldd != NULL))
- ldd->lld_sa_generation = sai->sai_generation;
- else
- rc = -ENOMEM;
+ /* not the same process, don't mark */
+ if (lli->lli_opendir_pid != cfs_curproc_pid())
+ return;
- return rc;
+ spin_lock(&lli->lli_lock);
+ if (likely(lli->lli_sai != NULL && ldd != NULL))
+ ldd->lld_sa_generation = lli->lli_sai->sai_generation;
+ spin_unlock(&lli->lli_lock);
}
static inline
diff --git a/lustre/llite/statahead.c b/lustre/llite/statahead.c
index e5fff85a5c..e3416758b5 100644
--- a/lustre/llite/statahead.c
+++ b/lustre/llite/statahead.c
@@ -741,8 +741,8 @@ static int ll_statahead_thread(void *arg)
struct inode *dir = parent->d_inode;
struct ll_inode_info *lli = ll_i2info(dir);
struct ll_sb_info *sbi = ll_i2sbi(dir);
- struct ll_statahead_info *sai = ll_sai_get(lli->lli_sai);
- struct ptlrpc_thread *thread = &sai->sai_thread;
+ struct ll_statahead_info *sai;
+ struct ptlrpc_thread *thread;
struct page *page;
__u64 pos = 0;
int first = 0;
@@ -750,12 +750,23 @@ static int ll_statahead_thread(void *arg)
struct ll_dir_chain chain;
ENTRY;
+ spin_lock(&lli->lli_lock);
+ if (unlikely(lli->lli_sai == NULL)) {
+ spin_unlock(&lli->lli_lock);
+ dput(parent);
+ RETURN(-EAGAIN);
+ } else {
+ sai = ll_sai_get(lli->lli_sai);
+ spin_unlock(&lli->lli_lock);
+ }
+
{
char pname[16];
snprintf(pname, 15, "ll_sa_%u", sta->sta_pid);
cfs_daemonize(pname);
}
+ thread = &sai->sai_thread;
sbi->ll_sa_total++;
spin_lock(&lli->lli_lock);
thread->t_flags = SVC_RUNNING;
@@ -1055,6 +1066,7 @@ out:
* \retval 1 -- stat ahead thread process such dentry, for lookup, it hit
* \retval -EEXIST -- stat ahead thread started, and this is the first dentry
* \retval -EBADFD -- statahead thread exit and not dentry available
+ * \retval -EAGAIN -- try to stat by caller
* \retval others -- error
*/
int do_statahead_enter(struct inode *dir, struct dentry **dentryp, int lookup)
@@ -1175,7 +1187,7 @@ int do_statahead_enter(struct inode *dir, struct dentry **dentryp, int lookup)
sai->sai_thread.t_flags = SVC_STOPPED;
ll_sai_put(sai);
LASSERT(lli->lli_sai == NULL);
- RETURN(rc);
+ RETURN(-EAGAIN);
}
l_wait_event(sai->sai_thread.t_ctl_waitq,
@@ -1192,20 +1204,16 @@ int do_statahead_enter(struct inode *dir, struct dentry **dentryp, int lookup)
/**
* update hit/miss count.
*/
-int ll_statahead_exit(struct dentry *dentry, int result)
+void ll_statahead_exit(struct dentry *dentry, int result)
{
- struct dentry *parent = dentry->d_parent;
- struct ll_inode_info *lli = ll_i2info(parent->d_inode);
- struct ll_sb_info *sbi = ll_i2sbi(parent->d_inode);
- int rc = 0;
+ struct dentry *parent = dentry->d_parent;
+ struct ll_inode_info *lli = ll_i2info(parent->d_inode);
+ struct ll_sb_info *sbi = ll_i2sbi(parent->d_inode);
+ struct ll_statahead_info *sai = lli->lli_sai;
+ struct ll_dentry_data *ldd = ll_d2d(dentry);
ENTRY;
- if (lli->lli_opendir_pid != cfs_curproc_pid())
- RETURN(-EBADFD);
-
- if (lli->lli_sai) {
- struct ll_statahead_info *sai = lli->lli_sai;
-
+ if (lli->lli_opendir_pid == cfs_curproc_pid() && sai) {
if (result >= 1) {
sbi->ll_sa_hit++;
sai->sai_hit++;
@@ -1235,7 +1243,8 @@ int ll_statahead_exit(struct dentry *dentry, int result)
if (!sa_is_stopped(sai))
cfs_waitq_signal(&sai->sai_thread.t_ctl_waitq);
ll_sai_entry_fini(sai);
- rc = ll_statahead_mark(dentry);
+ if (likely(ldd != NULL))
+ ldd->lld_sa_generation = sai->sai_generation;
}
- RETURN(rc);
+ EXIT;
}
--
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