* Insert it into sai_entries tail when init.
*/
static struct ll_sa_entry *
-ll_sa_entry_alloc(struct ll_statahead_info *sai, __u64 index,
- const char *name, int len)
+ll_sa_entry_alloc(struct ll_statahead_info *sai, __u64 index, const char *name,
+ int len)
{
struct ll_inode_info *lli;
struct ll_sa_entry *entry;
return NULL;
}
-static void ll_sa_entry_cleanup(struct ll_statahead_info *sai,
- struct ll_sa_entry *entry)
-{
- struct md_enqueue_info *minfo = entry->se_minfo;
- struct ptlrpc_request *req = entry->se_req;
-
- if (minfo) {
- entry->se_minfo = NULL;
- ll_intent_release(&minfo->mi_it);
- iput(minfo->mi_dir);
- OBD_FREE_PTR(minfo);
- }
-
- if (req) {
- entry->se_req = NULL;
- ptlrpc_req_finished(req);
- }
-}
-
static void ll_sa_entry_put(struct ll_statahead_info *sai,
struct ll_sa_entry *entry)
{
LASSERT(list_empty(&entry->se_list));
LASSERT(ll_sa_entry_unhashed(entry));
- ll_sa_entry_cleanup(sai, entry);
if (entry->se_inode)
iput(entry->se_inode);
list_for_each_entry_safe(pos, next, &sai->sai_entries, se_link) {
if (!is_omitted_entry(sai, pos->se_index))
break;
- do_sa_entry_fini(sai, pos);
+ /* keep those whose statahead RPC not finished */
+ if (pos->se_stat == SA_ENTRY_SUCC ||
+ pos->se_stat == SA_ENTRY_INVA)
+ do_sa_entry_fini(sai, pos);
}
}
* Inside lli_sa_lock.
*/
static void
-do_sa_entry_to_stated(struct ll_statahead_info *sai,
- struct ll_sa_entry *entry, se_stat_t stat)
+__sa_entry_post_stat(struct ll_statahead_info *sai, struct ll_sa_entry *entry,
+ se_stat_t stat)
{
struct ll_sa_entry *se;
- struct list_head *pos = &sai->sai_entries_stated;
+ struct list_head *pos = &sai->sai_entries_stated;
+
+ LASSERT(entry->se_stat == SA_ENTRY_INIT);
if (!list_empty(&entry->se_list))
list_del_init(&entry->se_list);
* \retval 1 -- entry to be destroyed.
* \retval 0 -- entry is inserted into stated list.
*/
-static int
-ll_sa_entry_to_stated(struct ll_statahead_info *sai,
- struct ll_sa_entry *entry, se_stat_t stat)
+static void
+sa_entry_post_stat(struct ll_statahead_info *sai, struct ll_sa_entry *entry,
+ se_stat_t stat)
{
struct ll_inode_info *lli = ll_i2info(sai->sai_inode);
- int ret = 1;
+ struct md_enqueue_info *minfo = entry->se_minfo;
+ struct ptlrpc_request *req = entry->se_req;
+
+ /* release resources used in RPC */
+ if (minfo) {
+ entry->se_minfo = NULL;
+ ll_intent_release(&minfo->mi_it);
+ iput(minfo->mi_dir);
+ OBD_FREE_PTR(minfo);
+ }
- ll_sa_entry_cleanup(sai, entry);
+ if (req) {
+ entry->se_req = NULL;
+ ptlrpc_req_finished(req);
+ }
spin_lock(&lli->lli_sa_lock);
- if (likely(entry->se_stat != SA_ENTRY_DEST)) {
- do_sa_entry_to_stated(sai, entry, stat);
- ret = 0;
- }
+ __sa_entry_post_stat(sai, entry, stat);
spin_unlock(&lli->lli_sa_lock);
-
- return ret;
}
/*
RETURN(sai);
}
-static inline struct ll_statahead_info *
-ll_sai_get(struct ll_statahead_info *sai)
+static inline struct ll_statahead_info *ll_sai_get(struct inode *dir)
{
- atomic_inc(&sai->sai_refcount);
+ struct ll_inode_info *lli = ll_i2info(dir);
+ struct ll_statahead_info *sai = NULL;
+
+ spin_lock(&lli->lli_sa_lock);
+ sai = lli->lli_sai;
+ if (sai != NULL)
+ atomic_inc(&sai->sai_refcount);
+ spin_unlock(&lli->lli_sa_lock);
+
return sai;
}
static void ll_sai_put(struct ll_statahead_info *sai)
{
- struct inode *inode = sai->sai_inode;
- struct ll_inode_info *lli = ll_i2info(inode);
- ENTRY;
+ struct ll_inode_info *lli = ll_i2info(sai->sai_inode);
if (atomic_dec_and_lock(&sai->sai_refcount, &lli->lli_sa_lock)) {
struct ll_sa_entry *entry, *next;
-
- if (unlikely(atomic_read(&sai->sai_refcount) > 0)) {
- /* It is race case, the interpret callback just hold
- * a reference count */
- spin_unlock(&lli->lli_sa_lock);
- RETURN_EXIT;
- }
-
- LASSERT(lli->lli_opendir_key == NULL);
- LASSERT(thread_is_stopped(&sai->sai_thread));
- LASSERT(thread_is_stopped(&sai->sai_agl_thread));
+ struct ll_sb_info *sbi = ll_i2sbi(sai->sai_inode);
lli->lli_sai = NULL;
- lli->lli_opendir_pid = 0;
spin_unlock(&lli->lli_sa_lock);
- if (sai->sai_sent > sai->sai_replied)
- CDEBUG(D_READA,"statahead for dir "DFID" does not "
- "finish: [sent:"LPU64"] [replied:"LPU64"]\n",
- PFID(&lli->lli_fid),
- sai->sai_sent, sai->sai_replied);
+ LASSERT(thread_is_stopped(&sai->sai_thread));
+ LASSERT(thread_is_stopped(&sai->sai_agl_thread));
+ LASSERT(sai->sai_sent == sai->sai_replied);
- list_for_each_entry_safe(entry, next,
- &sai->sai_entries, se_link)
+ list_for_each_entry_safe(entry, next, &sai->sai_entries,
+ se_link)
do_sa_entry_fini(sai, entry);
- LASSERT(list_empty(&sai->sai_entries));
- LASSERT(sa_received_empty(sai));
- LASSERT(list_empty(&sai->sai_entries_stated));
-
LASSERT(atomic_read(&sai->sai_cache_count) == 0);
LASSERT(agl_list_empty(sai));
+ LASSERT(atomic_read(&sai->sai_refcount) == 0);
- iput(inode);
+ iput(sai->sai_inode);
OBD_FREE_PTR(sai);
+ atomic_dec(&sbi->ll_sa_running);
}
-
- EXIT;
}
/* Do NOT forget to drop inode refcount when into sai_entries_agl. */
EXIT;
}
-static void ll_post_statahead(struct ll_statahead_info *sai)
+/* prepare inode for received statahead entry, and add it into agl list */
+static void sa_post_one(struct ll_statahead_info *sai,
+ struct ll_sa_entry *entry)
{
struct inode *dir = sai->sai_inode;
struct inode *child;
- struct ll_inode_info *lli = ll_i2info(dir);
- struct ll_sa_entry *entry;
struct md_enqueue_info *minfo;
struct lookup_intent *it;
struct ptlrpc_request *req;
int rc = 0;
ENTRY;
- spin_lock(&lli->lli_sa_lock);
- if (unlikely(sa_received_empty(sai))) {
- spin_unlock(&lli->lli_sa_lock);
- RETURN_EXIT;
- }
- entry = sa_first_received_entry(sai);
- atomic_inc(&entry->se_refcount);
- list_del_init(&entry->se_list);
- spin_unlock(&lli->lli_sa_lock);
-
LASSERT(entry->se_handle != 0);
minfo = entry->se_minfo;
EXIT;
out:
- /* The "ll_sa_entry_to_stated()" will drop related ldlm ibits lock
+ /* The "sa_entry_post_stat()" will drop related ldlm ibits lock
* reference count by calling "ll_intent_drop_lock()" in spite of the
* above operations failed or not. Do not worry about calling
* "ll_intent_drop_lock()" more than once. */
- rc = ll_sa_entry_to_stated(sai, entry,
- rc < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC);
- if (rc == 0 && entry->se_index == sai->sai_index_wait)
+ sa_entry_post_stat(sai, entry, rc < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC);
+ if (entry->se_index == sai->sai_index_wait)
wake_up(&sai->sai_waitq);
ll_sa_entry_put(sai, entry);
}
-static int ll_statahead_interpret(struct ptlrpc_request *req,
- struct md_enqueue_info *minfo, int rc)
+static void ll_post_statahead(struct ll_statahead_info *sai)
{
- struct lookup_intent *it = &minfo->mi_it;
- struct inode *dir = minfo->mi_dir;
- struct ll_inode_info *lli = ll_i2info(dir);
- struct ll_statahead_info *sai = NULL;
- struct ll_sa_entry *entry;
- int wakeup;
- ENTRY;
+ struct ll_inode_info *lli;
- if (it_disposition(it, DISP_LOOKUP_NEG))
- rc = -ENOENT;
+ lli = ll_i2info(sai->sai_inode);
- spin_lock(&lli->lli_sa_lock);
- /* stale entry */
- if (unlikely(lli->lli_sai == NULL ||
- lli->lli_sai->sai_generation != minfo->mi_generation)) {
- spin_unlock(&lli->lli_sa_lock);
- GOTO(out, rc = -ESTALE);
- } else {
- sai = ll_sai_get(lli->lli_sai);
- if (unlikely(!thread_is_running(&sai->sai_thread))) {
- sai->sai_replied++;
- spin_unlock(&lli->lli_sa_lock);
- GOTO(out, rc = -EBADFD);
- }
+ while (!sa_received_empty(sai)) {
+ struct ll_sa_entry *entry;
- entry = ll_sa_entry_get_byindex(sai, minfo->mi_cbdata);
- if (entry == NULL) {
- sai->sai_replied++;
+ spin_lock(&lli->lli_sa_lock);
+ if (unlikely(sa_received_empty(sai))) {
spin_unlock(&lli->lli_sa_lock);
- GOTO(out, rc = -EIDRM);
+ break;
}
-
- if (rc != 0) {
- do_sa_entry_to_stated(sai, entry, SA_ENTRY_INVA);
- wakeup = (entry->se_index == sai->sai_index_wait);
- } else {
- entry->se_minfo = minfo;
- entry->se_req = ptlrpc_request_addref(req);
- /* Release the async ibits lock ASAP to avoid deadlock
- * when statahead thread tries to enqueue lock on parent
- * for readpage and other tries to enqueue lock on child
- * with parent's lock held, for example: unlink. */
- entry->se_handle = it->d.lustre.it_lock_handle;
- ll_intent_drop_lock(it);
- wakeup = sa_received_empty(sai);
- list_add_tail(&entry->se_list,
- &sai->sai_entries_received);
- }
- sai->sai_replied++;
+ entry = sa_first_received_entry(sai);
+ atomic_inc(&entry->se_refcount);
+ list_del_init(&entry->se_list);
spin_unlock(&lli->lli_sa_lock);
- ll_sa_entry_put(sai, entry);
- if (wakeup)
- wake_up(&sai->sai_thread.t_ctl_waitq);
- }
+ sa_post_one(sai, entry);
+ }
- EXIT;
+ spin_lock(&lli->lli_agl_lock);
+ while (!agl_list_empty(sai)) {
+ struct ll_inode_info *clli;
-out:
- if (rc != 0) {
- ll_intent_release(it);
- iput(dir);
- OBD_FREE_PTR(minfo);
- }
- if (sai != NULL)
- ll_sai_put(sai);
- return rc;
+ clli = agl_first_entry(sai);
+ list_del_init(&clli->lli_agl_list);
+ spin_unlock(&lli->lli_agl_lock);
+
+ ll_agl_trigger(&clli->lli_vfs_inode, sai);
+
+ spin_lock(&lli->lli_agl_lock);
+ }
+ spin_unlock(&lli->lli_agl_lock);
+}
+
+static int ll_statahead_interpret(struct ptlrpc_request *req,
+ struct md_enqueue_info *minfo, int rc)
+{
+ struct lookup_intent *it = &minfo->mi_it;
+ struct inode *dir = minfo->mi_dir;
+ struct ll_inode_info *lli = ll_i2info(dir);
+ struct ll_statahead_info *sai;
+ struct ll_sa_entry *entry;
+ int wakeup;
+ ENTRY;
+
+ if (it_disposition(it, DISP_LOOKUP_NEG))
+ rc = -ENOENT;
+
+ sai = ll_sai_get(dir);
+ LASSERT(sai != NULL);
+ LASSERT(!thread_is_stopped(&sai->sai_thread));
+
+ spin_lock(&lli->lli_sa_lock);
+ entry = ll_sa_entry_get_byindex(sai, minfo->mi_cbdata);
+ LASSERT(entry != NULL);
+ if (rc != 0) {
+ __sa_entry_post_stat(sai, entry, SA_ENTRY_INVA);
+ wakeup = (entry->se_index == sai->sai_index_wait);
+ } else {
+ entry->se_minfo = minfo;
+ entry->se_req = ptlrpc_request_addref(req);
+ /* Release the async ibits lock ASAP to avoid deadlock
+ * when statahead thread tries to enqueue lock on parent
+ * for readpage and other tries to enqueue lock on child
+ * with parent's lock held, for example: unlink. */
+ entry->se_handle = it->d.lustre.it_lock_handle;
+ ll_intent_drop_lock(it);
+ wakeup = sa_received_empty(sai);
+ list_add_tail(&entry->se_list, &sai->sai_entries_received);
+ }
+ sai->sai_replied++;
+ spin_unlock(&lli->lli_sa_lock);
+
+ ll_sa_entry_put(sai, entry);
+ if (wakeup)
+ wake_up(&sai->sai_thread.t_ctl_waitq);
+
+ if (rc != 0) {
+ ll_intent_release(it);
+ iput(dir);
+ OBD_FREE_PTR(minfo);
+ }
+ ll_sai_put(sai);
+ RETURN(rc);
}
static void sa_args_fini(struct md_enqueue_info *minfo,
struct obd_capa **pcapa)
{
struct qstr *qstr = &entry->se_qstr;
- struct ll_inode_info *lli = ll_i2info(dir);
struct md_enqueue_info *minfo;
struct ldlm_enqueue_info *einfo;
struct md_op_data *op_data;
return PTR_ERR(op_data);
}
- minfo->mi_it.it_op = IT_GETATTR;
- minfo->mi_dir = igrab(dir);
- minfo->mi_cb = ll_statahead_interpret;
- minfo->mi_generation = lli->lli_sai->sai_generation;
- minfo->mi_cbdata = entry->se_index;
+ minfo->mi_it.it_op = IT_GETATTR;
+ minfo->mi_dir = igrab(dir);
+ minfo->mi_cb = ll_statahead_interpret;
+ minfo->mi_cbdata = entry->se_index;
einfo->ei_type = LDLM_IBITS;
einfo->ei_mode = it_to_lock_mode(&minfo->mi_it);
RETURN(rc);
}
-static void ll_statahead_one(struct dentry *parent, const char* entry_name,
- int entry_name_len)
+static void ll_statahead_one(struct dentry *parent, const char *name,
+ const int namelen)
{
- struct inode *dir = parent->d_inode;
- struct ll_inode_info *lli = ll_i2info(dir);
- struct ll_statahead_info *sai = lli->lli_sai;
- struct dentry *dentry = NULL;
- struct ll_sa_entry *entry;
- int rc;
- int rc1;
- ENTRY;
+ struct inode *dir = parent->d_inode;
+ struct ll_inode_info *lli = ll_i2info(dir);
+ struct ll_statahead_info *sai = lli->lli_sai;
+ struct dentry *dentry = NULL;
+ struct ll_sa_entry *entry;
+ int rc;
+ ENTRY;
- entry = ll_sa_entry_alloc(sai, sai->sai_index, entry_name,
- entry_name_len);
- if (IS_ERR(entry))
- RETURN_EXIT;
+ entry = ll_sa_entry_alloc(sai, sai->sai_index, name,namelen);
+ if (IS_ERR(entry))
+ RETURN_EXIT;
- dentry = d_lookup(parent, &entry->se_qstr);
- if (!dentry) {
- rc = do_sa_lookup(dir, entry);
- } else {
- rc = do_sa_revalidate(dir, entry, dentry);
- if (rc == 1 && agl_should_run(sai, dentry->d_inode))
- ll_agl_add(sai, dentry->d_inode, entry->se_index);
- }
+ dentry = d_lookup(parent, &entry->se_qstr);
+ if (!dentry) {
+ rc = do_sa_lookup(dir, entry);
+ } else {
+ rc = do_sa_revalidate(dir, entry, dentry);
+ if (rc == 1 && agl_should_run(sai, dentry->d_inode))
+ ll_agl_add(sai, dentry->d_inode, entry->se_index);
+ }
- if (dentry != NULL)
- dput(dentry);
+ if (dentry != NULL)
+ dput(dentry);
if (rc) {
- rc1 = ll_sa_entry_to_stated(sai, entry,
- rc < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC);
- if (rc1 == 0 && entry->se_index == sai->sai_index_wait)
+ sa_entry_post_stat(sai, entry,
+ rc < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC);
+ if (entry->se_index == sai->sai_index_wait)
wake_up(&sai->sai_waitq);
} else {
sai->sai_sent++;
}
- sai->sai_index++;
- /* drop one refcount on entry by ll_sa_entry_alloc */
- ll_sa_entry_put(sai, entry);
+ sai->sai_index++;
+ /* drop one refcount on entry by ll_sa_entry_alloc */
+ ll_sa_entry_put(sai, entry);
- EXIT;
+ EXIT;
}
static int ll_agl_thread(void *arg)
{
- struct dentry *parent = (struct dentry *)arg;
- struct inode *dir = parent->d_inode;
- struct ll_inode_info *plli = ll_i2info(dir);
- struct ll_inode_info *clli;
- struct ll_sb_info *sbi = ll_i2sbi(dir);
- struct ll_statahead_info *sai = ll_sai_get(plli->lli_sai);
- struct ptlrpc_thread *thread = &sai->sai_agl_thread;
- struct l_wait_info lwi = { 0 };
- ENTRY;
+ struct dentry *parent = (struct dentry *)arg;
+ struct inode *dir = parent->d_inode;
+ struct ll_inode_info *plli = ll_i2info(dir);
+ struct ll_inode_info *clli;
+ struct ll_sb_info *sbi = ll_i2sbi(dir);
+ struct ll_statahead_info *sai;
+ struct ptlrpc_thread *thread;
+ struct l_wait_info lwi = { 0 };
+ ENTRY;
+
+ sai = ll_sai_get(dir);
+ thread = &sai->sai_agl_thread;
thread->t_pid = current_pid();
CDEBUG(D_READA, "agl thread started: sai %p, parent %.*s\n",
sai, parent->d_name.len, parent->d_name.name);
static int ll_statahead_thread(void *arg)
{
- struct dentry *parent = (struct dentry *)arg;
- struct inode *dir = parent->d_inode;
- struct ll_inode_info *plli = ll_i2info(dir);
- struct ll_inode_info *clli;
- struct ll_sb_info *sbi = ll_i2sbi(dir);
- struct ll_statahead_info *sai = ll_sai_get(plli->lli_sai);
- struct ptlrpc_thread *thread = &sai->sai_thread;
- struct ptlrpc_thread *agl_thread = &sai->sai_agl_thread;
- int first = 0;
- int rc = 0;
- struct md_op_data *op_data;
- struct ll_dir_chain chain;
- struct l_wait_info lwi = { 0 };
- struct page *page = NULL;
- __u64 pos = 0;
+ struct dentry *parent = (struct dentry *)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;
+ struct ptlrpc_thread *thread;
+ struct ptlrpc_thread *agl_thread;
+ int first = 0;
+ struct md_op_data *op_data;
+ struct ll_dir_chain chain;
+ struct l_wait_info lwi = { 0 };
+ struct page *page = NULL;
+ __u64 pos = 0;
+ int rc = 0;
ENTRY;
+ sai = ll_sai_get(dir);
+ thread = &sai->sai_thread;
+ agl_thread = &sai->sai_agl_thread;
thread->t_pid = current_pid();
CDEBUG(D_READA, "statahead thread starting: sai %p, parent %.*s\n",
sai, parent->d_name.len, parent->d_name.name);
op_data = ll_prep_md_op_data(NULL, dir, dir, NULL, 0, 0,
LUSTRE_OPC_ANY, dir);
if (IS_ERR(op_data))
- GOTO(out_put, rc = PTR_ERR(op_data));
+ GOTO(out, rc = PTR_ERR(op_data));
op_data->op_max_pages = ll_i2sbi(dir)->ll_md_brw_pages;
ll_start_agl(parent, sai);
atomic_inc(&sbi->ll_sa_total);
- spin_lock(&plli->lli_sa_lock);
+ spin_lock(&lli->lli_sa_lock);
if (thread_is_init(thread))
/* If someone else has changed the thread state
* (e.g. already changed to SVC_STOPPING), we can't just
* blindly overwrite that setting. */
thread_set_flags(thread, SVC_RUNNING);
- spin_unlock(&plli->lli_sa_lock);
+ spin_unlock(&lli->lli_sa_lock);
wake_up(&thread->t_ctl_waitq);
ll_dir_chain_init(&chain);
- page = ll_get_dir_page(dir, op_data, pos, &chain);
- while (1) {
+ while (pos != MDS_DIR_END_OFF && thread_is_running(thread)) {
struct lu_dirpage *dp;
struct lu_dirent *ent;
+ sai->sai_in_readpage = 1;
+ page = ll_get_dir_page(dir, op_data, pos, &chain);
+ sai->sai_in_readpage = 0;
if (IS_ERR(page)) {
rc = PTR_ERR(page);
CDEBUG(D_READA, "error reading dir "DFID" at "LPU64
"/"LPU64" opendir_pid = %u: rc = %d\n",
PFID(ll_inode2fid(dir)), pos, sai->sai_index,
- plli->lli_opendir_pid, rc);
- GOTO(out, rc);
+ lli->lli_opendir_pid, rc);
+ break;
}
dp = page_address(page);
- for (ent = lu_dirent_start(dp); ent != NULL;
+ for (ent = lu_dirent_start(dp);
+ ent != NULL && thread_is_running(thread) &&
+ !sa_low_hit(sai);
ent = lu_dirent_next(ent)) {
__u64 hash;
int namelen;
if (unlikely(++first == 1))
continue;
-keep_it:
- l_wait_event(thread->t_ctl_waitq,
- !sa_sent_full(sai) ||
- !sa_received_empty(sai) ||
- !agl_list_empty(sai) ||
- !thread_is_running(thread),
- &lwi);
+ /* wait for spare statahead window */
+ do {
+ l_wait_event(thread->t_ctl_waitq,
+ !sa_sent_full(sai) ||
+ !sa_received_empty(sai) ||
+ !agl_list_empty(sai) ||
+ !thread_is_running(thread),
+ &lwi);
-interpret_it:
- while (!sa_received_empty(sai))
ll_post_statahead(sai);
+ } while (sa_sent_full(sai) &&
+ thread_is_running(thread));
- if (unlikely(!thread_is_running(thread))) {
- ll_release_page(dir, page, false);
- GOTO(out, rc = 0);
- }
-
- /* If no window for metadata statahead, but there are
- * some AGL entries to be triggered, then try to help
- * to process the AGL entries. */
- if (sa_sent_full(sai)) {
- spin_lock(&plli->lli_agl_lock);
- while (!agl_list_empty(sai)) {
- clli = agl_first_entry(sai);
- list_del_init(&clli->lli_agl_list);
- spin_unlock(&plli->lli_agl_lock);
- ll_agl_trigger(&clli->lli_vfs_inode,
- sai);
-
- if (!sa_received_empty(sai))
- goto interpret_it;
-
- if (unlikely(
- !thread_is_running(thread))) {
- ll_release_page(dir, page,
- false);
- GOTO(out, rc = 0);
- }
-
- if (!sa_sent_full(sai))
- goto do_it;
-
- spin_lock(&plli->lli_agl_lock);
- }
- spin_unlock(&plli->lli_agl_lock);
-
- goto keep_it;
- }
-do_it:
ll_statahead_one(parent, name, namelen);
}
pos = le64_to_cpu(dp->ldp_hash_end);
- if (pos == MDS_DIR_END_OFF) {
- /*
- * End of directory reached.
- */
- ll_release_page(dir, page, false);
- while (1) {
- l_wait_event(thread->t_ctl_waitq,
- !sa_received_empty(sai) ||
- sai->sai_sent == sai->sai_replied ||
- !thread_is_running(thread),
- &lwi);
+ ll_release_page(dir, page,
+ le32_to_cpu(dp->ldp_flags) & LDF_COLLIDE);
- while (!sa_received_empty(sai))
- ll_post_statahead(sai);
-
- if (unlikely(!thread_is_running(thread)))
- GOTO(out, rc = 0);
+ if (sa_low_hit(sai)) {
+ rc = -EFAULT;
+ atomic_inc(&sbi->ll_sa_wrong);
+ CDEBUG(D_READA, "Statahead for dir "DFID" hit "
+ "ratio too low: hit/miss "LPU64"/"LPU64
+ ", sent/replied "LPU64"/"LPU64", stopping "
+ "statahead thread: pid %d\n",
+ PFID(&lli->lli_fid), sai->sai_hit,
+ sai->sai_miss, sai->sai_sent,
+ sai->sai_replied, current_pid());
+ break;
+ }
+ }
+ ll_dir_chain_fini(&chain);
+ ll_finish_md_op_data(op_data);
- if (sai->sai_sent == sai->sai_replied &&
- sa_received_empty(sai))
- break;
- }
+ if (rc < 0) {
+ spin_lock(&lli->lli_sa_lock);
+ thread_set_flags(thread, SVC_STOPPING);
+ lli->lli_sa_enabled = 0;
+ spin_unlock(&lli->lli_sa_lock);
+ }
- spin_lock(&plli->lli_agl_lock);
- while (!agl_list_empty(sai) &&
- thread_is_running(thread)) {
- clli = agl_first_entry(sai);
- list_del_init(&clli->lli_agl_list);
- spin_unlock(&plli->lli_agl_lock);
- ll_agl_trigger(&clli->lli_vfs_inode, sai);
- spin_lock(&plli->lli_agl_lock);
- }
- spin_unlock(&plli->lli_agl_lock);
+ /* statahead is finished, but statahead entries need to be cached, wait
+ * for file release to stop me. */
+ while (thread_is_running(thread)) {
+ l_wait_event(thread->t_ctl_waitq,
+ !sa_received_empty(sai) ||
+ !agl_list_empty(sai) ||
+ !thread_is_running(thread),
+ &lwi);
- GOTO(out, rc = 0);
- } else {
- /*
- * chain is exhausted.
- * Normal case: continue to the next page.
- */
- ll_release_page(dir, page, le32_to_cpu(dp->ldp_flags) &
- LDF_COLLIDE);
- sai->sai_in_readpage = 1;
- page = ll_get_dir_page(dir, op_data, pos, &chain);
- sai->sai_in_readpage = 0;
- }
+ ll_post_statahead(sai);
}
-out:
+
EXIT;
- ll_dir_chain_fini(&chain);
- ll_finish_md_op_data(op_data);
-out_put:
- if (sai->sai_agl_valid) {
- spin_lock(&plli->lli_agl_lock);
+out:
+ if (sai->sai_agl_valid) {
+ spin_lock(&lli->lli_agl_lock);
thread_set_flags(agl_thread, SVC_STOPPING);
- spin_unlock(&plli->lli_agl_lock);
+ spin_unlock(&lli->lli_agl_lock);
wake_up(&agl_thread->t_ctl_waitq);
CDEBUG(D_READA, "stop agl thread: sai %p pid %u\n",
l_wait_event(agl_thread->t_ctl_waitq,
thread_is_stopped(agl_thread),
&lwi);
- } else {
- /* Set agl_thread flags anyway. */
- thread_set_flags(&sai->sai_agl_thread, SVC_STOPPED);
- }
- spin_lock(&plli->lli_sa_lock);
- if (!sa_received_empty(sai)) {
- thread_set_flags(thread, SVC_STOPPING);
- spin_unlock(&plli->lli_sa_lock);
-
- /* To release the resources held by received entries. */
- while (!sa_received_empty(sai))
- ll_post_statahead(sai);
+ } else {
+ /* Set agl_thread flags anyway. */
+ thread_set_flags(agl_thread, SVC_STOPPED);
+ }
- spin_lock(&plli->lli_sa_lock);
+ /* wait for inflight statahead RPCs to finish, and then we can free sai
+ * safely because statahead RPC will access sai data */
+ while (sai->sai_sent != sai->sai_replied) {
+ /* in case we're not woken up, timeout wait */
+ lwi = LWI_TIMEOUT(HZ >> 3, NULL, NULL);
+ l_wait_event(thread->t_ctl_waitq,
+ sai->sai_sent == sai->sai_replied, &lwi);
}
+
+ /* release resources held by received entries. */
+ ll_post_statahead(sai);
+
+ spin_lock(&lli->lli_sa_lock);
thread_set_flags(thread, SVC_STOPPED);
- spin_unlock(&plli->lli_sa_lock);
+ spin_unlock(&lli->lli_sa_lock);
+
wake_up(&sai->sai_waitq);
wake_up(&thread->t_ctl_waitq);
ll_sai_put(sai);
return rc;
}
-/**
- * called in ll_file_release().
- */
-void ll_stop_statahead(struct inode *dir, void *key)
+/* authorize opened dir handle @key to statahead later */
+void ll_authorize_statahead(struct inode *dir, void *key)
{
struct ll_inode_info *lli = ll_i2info(dir);
- if (unlikely(key == NULL))
- return;
-
spin_lock(&lli->lli_sa_lock);
- if (lli->lli_opendir_key != key || lli->lli_opendir_pid == 0) {
- spin_unlock(&lli->lli_sa_lock);
- return;
- }
+ if (lli->lli_opendir_key == NULL && lli->lli_sai == NULL) {
+ /*
+ * if lli_sai is not NULL, it means previous statahead is not
+ * finished yet, we'd better not start a new statahead for now.
+ */
+ LASSERT(lli->lli_opendir_pid == 0);
+ lli->lli_opendir_key = key;
+ lli->lli_opendir_pid = current_pid();
+ lli->lli_sa_enabled = 1;
+ }
+ spin_unlock(&lli->lli_sa_lock);
+}
- lli->lli_opendir_key = NULL;
+/* deauthorize opened dir handle @key to statahead, but statahead thread may
+ * still be running, notify it to quit. */
+void ll_deauthorize_statahead(struct inode *dir, void *key)
+{
+ struct ll_inode_info *lli = ll_i2info(dir);
+ struct ll_statahead_info *sai;
- if (lli->lli_sai) {
- struct l_wait_info lwi = { 0 };
- struct ptlrpc_thread *thread = &lli->lli_sai->sai_thread;
+ LASSERT(lli->lli_opendir_key == key);
+ LASSERT(lli->lli_opendir_pid != 0);
- if (!thread_is_stopped(thread)) {
- thread_set_flags(thread, SVC_STOPPING);
- spin_unlock(&lli->lli_sa_lock);
- wake_up(&thread->t_ctl_waitq);
-
- CDEBUG(D_READA, "stop statahead thread: sai %p pid %u\n",
- lli->lli_sai, (unsigned int)thread->t_pid);
- l_wait_event(thread->t_ctl_waitq,
- thread_is_stopped(thread),
- &lwi);
- } else {
- spin_unlock(&lli->lli_sa_lock);
- }
+ CDEBUG(D_READA, "deauthorize statahead for "DFID"\n",
+ PFID(&lli->lli_fid));
+ spin_lock(&lli->lli_sa_lock);
+ lli->lli_opendir_key = NULL;
+ lli->lli_opendir_pid = 0;
+ lli->lli_sa_enabled = 0;
+ sai = lli->lli_sai;
+ if (sai != NULL && thread_is_running(&sai->sai_thread)) {
/*
- * Put the ref which was held when first statahead_enter.
- * It maybe not the last ref for some statahead requests
- * maybe inflight.
+ * statahead thread may not quit yet because it needs to cache
+ * stated entries, now it's time to tell it to quit.
*/
- ll_sai_put(lli->lli_sai);
- } else {
- lli->lli_opendir_pid = 0;
- spin_unlock(&lli->lli_sa_lock);
+ thread_set_flags(&sai->sai_thread, SVC_STOPPING);
+ wake_up(&sai->sai_thread.t_ctl_waitq);
}
+ spin_unlock(&lli->lli_sa_lock);
}
enum {
static void
ll_sai_unplug(struct ll_statahead_info *sai, struct ll_sa_entry *entry)
{
- struct ptlrpc_thread *thread = &sai->sai_thread;
- struct ll_sb_info *sbi = ll_i2sbi(sai->sai_inode);
- int hit;
- ENTRY;
-
- if (entry != NULL && entry->se_stat == SA_ENTRY_SUCC)
- hit = 1;
- else
- hit = 0;
-
- ll_sa_entry_fini(sai, entry);
- if (hit) {
- sai->sai_hit++;
- sai->sai_consecutive_miss = 0;
- sai->sai_max = min(2 * sai->sai_max, sbi->ll_sa_max);
- } else {
- struct ll_inode_info *lli = ll_i2info(sai->sai_inode);
+ if (entry != NULL && entry->se_stat == SA_ENTRY_SUCC) {
+ struct ll_sb_info *sbi = ll_i2sbi(sai->sai_inode);
+ sai->sai_hit++;
+ sai->sai_consecutive_miss = 0;
+ sai->sai_max = min(2 * sai->sai_max, sbi->ll_sa_max);
+ } else {
sai->sai_miss++;
sai->sai_consecutive_miss++;
- if (sa_low_hit(sai) && thread_is_running(thread)) {
- atomic_inc(&sbi->ll_sa_wrong);
- CDEBUG(D_READA, "Statahead for dir "DFID" hit "
- "ratio too low: hit/miss "LPU64"/"LPU64
- ", sent/replied "LPU64"/"LPU64", stopping "
- "statahead thread\n",
- PFID(&lli->lli_fid), sai->sai_hit,
- sai->sai_miss, sai->sai_sent,
- sai->sai_replied);
- spin_lock(&lli->lli_sa_lock);
- if (!thread_is_stopped(thread))
- thread_set_flags(thread, SVC_STOPPING);
- spin_unlock(&lli->lli_sa_lock);
- }
}
-
- if (!thread_is_stopped(thread))
- wake_up(&thread->t_ctl_waitq);
-
- EXIT;
+ ll_sa_entry_fini(sai, entry);
+ wake_up(&sai->sai_thread.t_ctl_waitq);
}
-/**
- * Start statahead thread if this is the first dir entry.
- * Otherwise if a thread is started already, wait it until it is ahead of me.
- * \retval 1 -- find entry with lock in cache, the caller needs to do
- * nothing.
- * \retval 0 -- find entry in cache, but without lock, the caller needs
- * refresh from MDS.
- * \retval others -- the caller need to process as non-statahead.
- */
-int do_statahead_enter(struct inode *dir, struct dentry **dentryp,
- int only_unplug)
+static int revalidate_statahead_dentry(struct inode *dir,
+ struct ll_statahead_info *sai,
+ struct dentry **dentryp,
+ int only_unplug)
{
- struct ll_inode_info *lli = ll_i2info(dir);
- struct ll_statahead_info *sai = lli->lli_sai;
- struct dentry *parent;
- struct ll_sa_entry *entry;
- struct ptlrpc_thread *thread;
- struct l_wait_info lwi = { 0 };
- struct task_struct *task;
- int rc = 0;
- struct ll_inode_info *plli;
+ struct ll_sa_entry *entry = NULL;
+ struct l_wait_info lwi = { 0 };
+ int rc = 0;
ENTRY;
- LASSERT(lli->lli_opendir_pid == current_pid());
-
- if (sai) {
- thread = &sai->sai_thread;
- if (unlikely(thread_is_stopped(thread) &&
- list_empty(&sai->sai_entries_stated))) {
- /* to release resource */
- ll_stop_statahead(dir, lli->lli_opendir_key);
- RETURN(-EAGAIN);
- }
+ if ((*dentryp)->d_name.name[0] == '.') {
+ if (sai->sai_ls_all ||
+ sai->sai_miss_hidden >= sai->sai_skip_hidden) {
+ /*
+ * Hidden dentry is the first one, or statahead
+ * thread does not skip so many hidden dentries
+ * before "sai_ls_all" enabled as below.
+ */
+ } else {
+ if (!sai->sai_ls_all)
+ /*
+ * It maybe because hidden dentry is not
+ * the first one, "sai_ls_all" was not
+ * set, then "ls -al" missed. Enable
+ * "sai_ls_all" for such case.
+ */
+ sai->sai_ls_all = 1;
- if ((*dentryp)->d_name.name[0] == '.') {
- if (sai->sai_ls_all ||
- sai->sai_miss_hidden >= sai->sai_skip_hidden) {
- /*
- * Hidden dentry is the first one, or statahead
- * thread does not skip so many hidden dentries
- * before "sai_ls_all" enabled as below.
- */
- } else {
- if (!sai->sai_ls_all)
- /*
- * It maybe because hidden dentry is not
- * the first one, "sai_ls_all" was not
- * set, then "ls -al" missed. Enable
- * "sai_ls_all" for such case.
- */
- sai->sai_ls_all = 1;
-
- /*
- * Such "getattr" has been skipped before
- * "sai_ls_all" enabled as above.
- */
- sai->sai_miss_hidden++;
- RETURN(-EAGAIN);
- }
- }
+ /*
+ * Such "getattr" has been skipped before
+ * "sai_ls_all" enabled as above.
+ */
+ sai->sai_miss_hidden++;
+ RETURN(-EAGAIN);
+ }
+ }
- entry = ll_sa_entry_get_byname(sai, &(*dentryp)->d_name);
- if (entry == NULL || only_unplug) {
- ll_sai_unplug(sai, entry);
- RETURN(entry ? 1 : -EAGAIN);
- }
+ entry = ll_sa_entry_get_byname(sai, &(*dentryp)->d_name);
+ if (entry == NULL || only_unplug) {
+ ll_sai_unplug(sai, entry);
+ RETURN(entry ? 1 : -EAGAIN);
+ }
- /* if statahead is busy in readdir, help it do post-work */
- while (!ll_sa_entry_stated(entry) &&
- sai->sai_in_readpage && !sa_received_empty(sai))
- ll_post_statahead(sai);
-
- if (!ll_sa_entry_stated(entry)) {
- sai->sai_index_wait = entry->se_index;
- lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(30), NULL,
- LWI_ON_SIGNAL_NOOP, NULL);
- rc = l_wait_event(sai->sai_waitq,
- ll_sa_entry_stated(entry) ||
- thread_is_stopped(thread),
- &lwi);
- if (rc < 0) {
- ll_sai_unplug(sai, entry);
- RETURN(-EAGAIN);
- }
- }
+ /* if statahead is busy in readdir, help it do post-work */
+ if (!ll_sa_entry_stated(entry) && sai->sai_in_readpage)
+ ll_post_statahead(sai);
+
+ if (!ll_sa_entry_stated(entry)) {
+ sai->sai_index_wait = entry->se_index;
+ lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(30), NULL,
+ LWI_ON_SIGNAL_NOOP, NULL);
+ rc = l_wait_event(sai->sai_waitq,
+ ll_sa_entry_stated(entry) ||
+ thread_is_stopped(&sai->sai_thread),
+ &lwi);
+ if (rc < 0) {
+ ll_sai_unplug(sai, entry);
+ RETURN(-EAGAIN);
+ }
+ }
- if (entry->se_stat == SA_ENTRY_SUCC &&
- entry->se_inode != NULL) {
- struct inode *inode = entry->se_inode;
- struct lookup_intent it = { .it_op = IT_GETATTR,
- .d.lustre.it_lock_handle =
- entry->se_handle };
- __u64 bits;
-
- rc = md_revalidate_lock(ll_i2mdexp(dir), &it,
- ll_inode2fid(inode), &bits);
- if (rc == 1) {
- if ((*dentryp)->d_inode == NULL) {
- struct dentry *alias;
-
- alias = ll_splice_alias(inode,
- *dentryp);
- if (IS_ERR(alias)) {
- ll_sai_unplug(sai, entry);
- RETURN(PTR_ERR(alias));
- }
- *dentryp = alias;
- } else if ((*dentryp)->d_inode != inode) {
- /* revalidate, but inode is recreated */
- CDEBUG(D_READA,
- "%s: stale dentry %.*s inode "
- DFID", statahead inode "DFID
- "\n",
- ll_get_fsname((*dentryp)->d_inode->i_sb, NULL, 0),
- (*dentryp)->d_name.len,
- (*dentryp)->d_name.name,
- PFID(ll_inode2fid((*dentryp)->d_inode)),
- PFID(ll_inode2fid(inode)));
- ll_intent_release(&it);
+ if (entry->se_stat == SA_ENTRY_SUCC && entry->se_inode != NULL) {
+ struct inode *inode = entry->se_inode;
+ struct lookup_intent it = { .it_op = IT_GETATTR,
+ .d.lustre.it_lock_handle =
+ entry->se_handle };
+ __u64 bits;
+
+ rc = md_revalidate_lock(ll_i2mdexp(dir), &it,
+ ll_inode2fid(inode), &bits);
+ if (rc == 1) {
+ if ((*dentryp)->d_inode == NULL) {
+ struct dentry *alias;
+
+ alias = ll_splice_alias(inode, *dentryp);
+ if (IS_ERR(alias)) {
ll_sai_unplug(sai, entry);
- RETURN(-ESTALE);
- } else {
- iput(inode);
+ RETURN(PTR_ERR(alias));
}
- entry->se_inode = NULL;
+ *dentryp = alias;
+ } else if ((*dentryp)->d_inode != inode) {
+ /* revalidate, but inode is recreated */
+ CDEBUG(D_READA,
+ "%s: stale dentry %.*s inode "
+ DFID", statahead inode "DFID
+ "\n",
+ ll_get_fsname((*dentryp)->d_inode->i_sb,
+ NULL, 0),
+ (*dentryp)->d_name.len,
+ (*dentryp)->d_name.name,
+ PFID(ll_inode2fid((*dentryp)->d_inode)),
+ PFID(ll_inode2fid(inode)));
+ ll_sai_unplug(sai, entry);
+ RETURN(-ESTALE);
+ } else {
+ iput(inode);
+ }
+ entry->se_inode = NULL;
- if ((bits & MDS_INODELOCK_LOOKUP) &&
- d_lustre_invalid(*dentryp))
- d_lustre_revalidate(*dentryp);
- ll_intent_release(&it);
- }
- }
+ if ((bits & MDS_INODELOCK_LOOKUP) &&
+ d_lustre_invalid(*dentryp))
+ d_lustre_revalidate(*dentryp);
+ ll_intent_release(&it);
+ }
+ }
- ll_sai_unplug(sai, entry);
- RETURN(rc);
- }
+ ll_sai_unplug(sai, entry);
+ RETURN(rc);
+}
- /* I am the "lli_opendir_pid" owner, only me can set "lli_sai". */
- rc = is_first_dirent(dir, *dentryp);
- if (rc == LS_NONE_FIRST_DE)
- /* It is not "ls -{a}l" operation, no need statahead for it. */
- GOTO(out, rc = -EAGAIN);
+static int start_statahead_thread(struct inode *dir, struct dentry *dentry)
+{
+ struct ll_inode_info *lli = ll_i2info(dir);
+ struct ll_statahead_info *sai = NULL;
+ struct dentry *parent;
+ struct ptlrpc_thread *thread;
+ struct l_wait_info lwi = { 0 };
+ struct task_struct *task;
+ int rc;
+ ENTRY;
- sai = ll_sai_alloc();
- if (sai == NULL)
- GOTO(out, rc = -ENOMEM);
+ /* I am the "lli_opendir_pid" owner, only me can set "lli_sai". */
+ rc = is_first_dirent(dir, dentry);
+ if (rc == LS_NONE_FIRST_DE)
+ /* It is not "ls -{a}l" operation, no need statahead for it. */
+ GOTO(out, rc = -EAGAIN);
+
+ sai = ll_sai_alloc();
+ if (sai == NULL)
+ GOTO(out, rc = -ENOMEM);
+
+ sai->sai_ls_all = (rc == LS_FIRST_DOT_DE);
+ sai->sai_inode = igrab(dir);
+ if (unlikely(sai->sai_inode == NULL)) {
+ CWARN("Do not start stat ahead on dying inode "DFID"\n",
+ PFID(&lli->lli_fid));
+ GOTO(out, rc = -ESTALE);
+ }
- sai->sai_ls_all = (rc == LS_FIRST_DOT_DE);
- sai->sai_inode = igrab(dir);
- if (unlikely(sai->sai_inode == NULL)) {
- CWARN("Do not start stat ahead on dying inode "DFID"\n",
- PFID(&lli->lli_fid));
- GOTO(out, rc = -ESTALE);
- }
+ /* get parent reference count here, and put it in ll_statahead_thread */
+ parent = dget(dentry->d_parent);
+ if (unlikely(sai->sai_inode != parent->d_inode)) {
+ struct ll_inode_info *nlli = ll_i2info(parent->d_inode);
- /* get parent reference count here, and put it in ll_statahead_thread */
- parent = dget((*dentryp)->d_parent);
- if (unlikely(sai->sai_inode != parent->d_inode)) {
- struct ll_inode_info *nlli = ll_i2info(parent->d_inode);
-
- CWARN("Race condition, someone changed %.*s just now: "
- "old parent "DFID", new parent "DFID"\n",
- (*dentryp)->d_name.len, (*dentryp)->d_name.name,
- PFID(&lli->lli_fid), PFID(&nlli->lli_fid));
- dput(parent);
- iput(sai->sai_inode);
- GOTO(out, rc = -EAGAIN);
- }
+ CWARN("Race condition, someone changed %.*s just now: "
+ "old parent "DFID", new parent "DFID"\n",
+ dentry->d_name.len, dentry->d_name.name,
+ PFID(&lli->lli_fid), PFID(&nlli->lli_fid));
+ dput(parent);
+ iput(sai->sai_inode);
+ GOTO(out, rc = -EAGAIN);
+ }
CDEBUG(D_READA, "start statahead thread: sai %p, parent %.*s\n",
sai, parent->d_name.len, parent->d_name.name);
- /* The sai buffer already has one reference taken at allocation time,
- * but as soon as we expose the sai by attaching it to the lli that
- * default reference can be dropped by another thread calling
- * ll_stop_statahead. We need to take a local reference to protect
- * the sai buffer while we intend to access it. */
- ll_sai_get(sai);
lli->lli_sai = sai;
- plli = ll_i2info(parent->d_inode);
task = kthread_run(ll_statahead_thread, parent, "ll_sa_%u",
- plli->lli_opendir_pid);
+ lli->lli_opendir_pid);
thread = &sai->sai_thread;
if (IS_ERR(task)) {
rc = PTR_ERR(task);
CERROR("cannot start ll_sa thread: rc = %d\n", rc);
dput(parent);
- lli->lli_opendir_key = NULL;
- thread_set_flags(thread, SVC_STOPPED);
- thread_set_flags(&sai->sai_agl_thread, SVC_STOPPED);
- /* Drop both our own local reference and the default
- * reference from allocation time. */
- ll_sai_put(sai);
+ lli->lli_opendir_key = NULL;
+ thread_set_flags(thread, SVC_STOPPED);
+ thread_set_flags(&sai->sai_agl_thread, SVC_STOPPED);
ll_sai_put(sai);
- LASSERT(lli->lli_sai == NULL);
- RETURN(-EAGAIN);
- }
+ LASSERT(lli->lli_sai == NULL);
+ RETURN(-EAGAIN);
+ }
- l_wait_event(thread->t_ctl_waitq,
- thread_is_running(thread) || thread_is_stopped(thread),
- &lwi);
+ l_wait_event(thread->t_ctl_waitq,
+ thread_is_running(thread) || thread_is_stopped(thread),
+ &lwi);
+ atomic_inc(&ll_i2sbi(parent->d_inode)->ll_sa_running);
ll_sai_put(sai);
- /*
- * We don't stat-ahead for the first dirent since we are already in
- * lookup.
- */
- RETURN(-EAGAIN);
+ /*
+ * We don't stat-ahead for the first dirent since we are already in
+ * lookup.
+ */
+ RETURN(-EAGAIN);
out:
- if (sai != NULL)
- OBD_FREE_PTR(sai);
+ if (sai != NULL)
+ OBD_FREE_PTR(sai);
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);
- return rc;
+
+ RETURN(rc);
+}
+
+/**
+ * Start statahead thread if this is the first dir entry.
+ * Otherwise if a thread is started already, wait it until it is ahead of me.
+ * \retval 1 -- find entry with lock in cache, the caller needs to do
+ * nothing.
+ * \retval 0 -- find entry in cache, but without lock, the caller needs
+ * refresh from MDS.
+ * \retval others -- the caller need to process as non-statahead.
+ */
+int do_statahead_enter(struct inode *dir, struct dentry **dentryp,
+ int only_unplug)
+{
+ struct ll_statahead_info *sai;
+
+ sai = ll_sai_get(dir);
+ if (sai != NULL) {
+ int rc;
+
+ rc = revalidate_statahead_dentry(dir, sai, dentryp,
+ only_unplug);
+ CDEBUG(D_READA, "revalidate statahead %.*s: %d.\n",
+ (*dentryp)->d_name.len, (*dentryp)->d_name.name, rc);
+ ll_sai_put(sai);
+ return rc;
+ }
+
+ return start_statahead_thread(dir, *dentryp);
}
git://git.whamcloud.com / fs / lustre-release.git / commitdiff