LU-10934 llite: integrate statx() API with Lustre

[fs/lustre-release.git] / lustre / llite / statahead.c

diff --git a/lustre/llite/statahead.c b/lustre/llite/statahead.c
index e20dd4d..9a25ae7 100644 (file)
--- a/lustre/llite/statahead.c
+++ b/lustre/llite/statahead.c
@@ -992,10 +992,11 @@ static void ll_start_agl(struct dentry *parent, struct ll_statahead_info *sai)
                              "ll_agl_%u", plli->lli_opendir_pid);
        if (IS_ERR(task)) {
                CERROR("can't start ll_agl thread, rc: %ld\n", PTR_ERR(task));
+               sai->sai_agl_valid = 0;
                RETURN_EXIT;
        }
        sai->sai_agl_task = task;
-       sai->sai_agl_valid = 1;
+       LASSERT(sai->sai_agl_valid == 1);
        atomic_inc(&ll_i2sbi(d_inode(parent))->ll_agl_total);
        /* Get an extra reference that the thread holds */
        ll_sai_get(d_inode(parent));
@@ -1551,13 +1552,15 @@ out:
  * \param[in] dir      parent directory
  * \param[in] dentry   dentry that triggers statahead, normally the first
  *                     dirent under @dir
+ * \param[in] agl      indicate whether AGL is needed
  * \retval             -EAGAIN on success, because when this function is
  *                     called, it's already in lookup call, so client should
  *                     do it itself instead of waiting for statahead thread
  *                     to do it asynchronously.
  * \retval             negative number upon error
  */
-static int start_statahead_thread(struct inode *dir, struct dentry *dentry)
+static int start_statahead_thread(struct inode *dir, struct dentry *dentry,
+                                 bool agl)
 {
        struct ll_inode_info *lli = ll_i2info(dir);
        struct ll_statahead_info *sai = NULL;
@@ -1587,6 +1590,7 @@ static int start_statahead_thread(struct inode *dir, struct dentry *dentry)
                GOTO(out, rc = -ENOMEM);
 
        sai->sai_ls_all = (first == LS_FIRST_DOT_DE);
+       sai->sai_agl_valid = agl;
 
        /*
         * if current lli_opendir_key was deauthorized, or dir re-opened by
@@ -1616,7 +1620,7 @@ static int start_statahead_thread(struct inode *dir, struct dentry *dentry)
                GOTO(out, rc);
        }
 
-       if (ll_i2sbi(parent->d_inode)->ll_flags & LL_SBI_AGL_ENABLED)
+       if (ll_i2sbi(parent->d_inode)->ll_flags & LL_SBI_AGL_ENABLED && agl)
                ll_start_agl(parent, sai);
 
        atomic_inc(&ll_i2sbi(parent->d_inode)->ll_sa_total);
@@ -1647,6 +1651,25 @@ out:
        RETURN(rc);
 }
 
+/*
+ * Check whether statahead for @dir was started.
+ */
+static inline bool ll_statahead_started(struct inode *dir, bool agl)
+{
+       struct ll_inode_info *lli = ll_i2info(dir);
+       struct ll_statahead_info *sai;
+
+       spin_lock(&lli->lli_sa_lock);
+       sai = lli->lli_sai;
+       if (sai && sai->sai_agl_valid != agl)
+               CDEBUG(D_READA,
+                      "%s: Statahead AGL hint changed from %d to %d\n",
+                      ll_i2sbi(dir)->ll_fsname, sai->sai_agl_valid, agl);
+       spin_unlock(&lli->lli_sa_lock);
+
+       return !!sai;
+}
+
 /**
  * statahead entry function, this is called when client getattr on a file, it
  * will start statahead thread if this is the first dir entry, else revalidate
@@ -1654,6 +1677,26 @@ out:
  *
  * \param[in]  dir     parent directory
  * \param[out] dentryp dentry to getattr
+ * \param[in]  agl     whether start the agl thread
+ *
+ * \retval             1 on success
+ * \retval             0 revalidation from statahead cache failed, caller needs
+ *                     to getattr from server directly
+ * \retval             negative number on error, caller often ignores this and
+ *                     then getattr from server
+ */
+int ll_start_statahead(struct inode *dir, struct dentry *dentry, bool agl)
+{
+       if (!ll_statahead_started(dir, agl))
+               return start_statahead_thread(dir, dentry, agl);
+       return 0;
+}
+
+/**
+ * revalidate dentry from statahead cache.
+ *
+ * \param[in]  dir     parent directory
+ * \param[out] dentryp dentry to getattr
  * \param[in]  unplug  unplug statahead window only (normally for negative
  *                     dentry)
  * \retval             1 on success
@@ -1662,19 +1705,18 @@ out:
  * \retval             negative number on error, caller often ignores this and
  *                     then getattr from server
  */
-int ll_statahead(struct inode *dir, struct dentry **dentryp, bool unplug)
+int ll_revalidate_statahead(struct inode *dir, struct dentry **dentryp,
+                           bool unplug)
 {
        struct ll_statahead_info *sai;
+       int rc = 0;
 
        sai = ll_sai_get(dir);
        if (sai) {
-               int rc;
-
                rc = revalidate_statahead_dentry(dir, sai, dentryp, unplug);
                CDEBUG(D_READA, "revalidate statahead %pd: rc = %d.\n",
                       *dentryp, rc);
                ll_sai_put(sai);
-               return rc;
        }
-       return start_statahead_thread(dir, *dentryp);
+       return rc;
 }