* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
* Use is subject to license terms.
*
- * Copyright (c) 2011, 2013, Intel Corporation.
+ * Copyright (c) 2011, 2015, Intel Corporation.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
#include <linux/fs.h>
#include <linux/sched.h>
+#include <linux/kthread.h>
#include <linux/mm.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
/* sa_entry is not refcounted: statahead thread allocates it and do async stat,
* and in async stat callback ll_statahead_interpret() will add it into
- * sai_cb_entries, later statahead thread will call sa_handle_callback() to
+ * sai_interim_entries, later statahead thread will call sa_handle_callback() to
* instantiate entry and move it into sai_entries, and then only scanner process
* can access and free it. */
struct sa_entry {
- /* link into sai_cb_entries or sai_entries */
+ /* link into sai_interim_entries or sai_entries */
struct list_head se_list;
/* link into sai hash table locally */
struct list_head se_hash;
struct inode *se_inode;
/* entry name */
struct qstr se_qstr;
+ /* entry fid */
+ struct lu_fid se_fid;
};
static unsigned int sai_generation = 0;
return list_empty(&entry->se_hash);
}
-/*
- * The entry only can be released by the caller, it is necessary to hold lock.
- */
+/* sa_entry is ready to use */
static inline int sa_ready(struct sa_entry *entry)
{
smp_rmb();
return (entry->se_state != SA_ENTRY_INIT);
}
+/* hash value to put in sai_cache */
static inline int sa_hash(int val)
{
return val & LL_SA_CACHE_MASK;
}
-/*
- * Insert entry to hash SA table.
- */
+/* hash entry into sai_cache */
static inline void
sa_rehash(struct ll_statahead_info *sai, struct sa_entry *entry)
{
spin_unlock(&sai->sai_cache_lock[i]);
}
-/*
- * Remove entry from SA table.
- */
+/* unhash entry from sai_cache */
static inline void
sa_unhash(struct ll_statahead_info *sai, struct sa_entry *entry)
{
lli_agl_list);
}
+/* statahead window is full */
static inline int sa_sent_full(struct ll_statahead_info *sai)
{
return atomic_read(&sai->sai_cache_count) >= sai->sai_max;
}
+/* got async stat replies */
static inline int sa_has_callback(struct ll_statahead_info *sai)
{
return !list_empty(&sai->sai_interim_entries);
}
/*
- * If the given index is behind of statahead window more than
+ * if the given index is behind of statahead window more than
* SA_OMITTED_ENTRY_MAX, then it is old.
*/
static inline int is_omitted_entry(struct ll_statahead_info *sai, __u64 index)
sai->sai_index);
}
-/* allocate sa_entry and add it into hash to let scanner process to find it */
+/* allocate sa_entry and hash it to allow scanner process to find it */
static struct sa_entry *
-sa_alloc(struct ll_statahead_info *sai, __u64 index, const char *name, int len)
+sa_alloc(struct ll_statahead_info *sai, __u64 index, const char *name, int len,
+ const struct lu_fid *fid)
{
struct ll_inode_info *lli;
struct sa_entry *entry;
entry->se_qstr.hash = full_name_hash(name, len);
entry->se_qstr.len = len;
entry->se_qstr.name = dname;
+ entry->se_fid = *fid;
+
+ lli = ll_i2info(sai->sai_dentry->d_inode);
- lli = ll_i2info(sai->sai_inode);
spin_lock(&lli->lli_sa_lock);
INIT_LIST_HEAD(&entry->se_list);
sa_rehash(sai, entry);
RETURN(entry);
}
-/* free sa_entry which should have been unhashed and not in any list */
+/* free sa_entry, which should have been unhashed and not in any list */
static void sa_free(struct ll_statahead_info *sai, struct sa_entry *entry)
{
CDEBUG(D_READA, "free sa entry %.*s(%p) index "LPU64"\n",
atomic_dec(&sai->sai_cache_count);
}
-/* find sa_entry by name, used by directory scanner, lock is not needed because
- * only scanner can remove the entry from hash.
+/*
+ * find sa_entry by name, used by directory scanner, lock is not needed because
+ * only scanner can remove the entry from cache.
*/
static struct sa_entry *
sa_get(struct ll_statahead_info *sai, const struct qstr *qstr)
return NULL;
}
+/* unhash and unlink sa_entry, and then free it */
static inline void
sa_kill(struct ll_statahead_info *sai, struct sa_entry *entry)
{
- struct ll_inode_info *lli = ll_i2info(sai->sai_inode);
+ struct ll_inode_info *lli = ll_i2info(sai->sai_dentry->d_inode);
LASSERT(!sa_unhashed(entry));
LASSERT(!list_empty(&entry->se_list));
struct sa_entry *tmp, *next;
if (entry != NULL && entry->se_state == SA_ENTRY_SUCC) {
- struct ll_sb_info *sbi = ll_i2sbi(sai->sai_inode);
+ struct ll_sb_info *sbi = ll_i2sbi(sai->sai_dentry->d_inode);
sai->sai_hit++;
sai->sai_consecutive_miss = 0;
{
struct sa_entry *se;
struct list_head *pos = &sai->sai_entries;
+ __u64 index = entry->se_index;
LASSERT(!sa_ready(entry));
LASSERT(list_empty(&entry->se_list));
- entry->se_state = ret < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC;
-
list_for_each_entry_reverse(se, &sai->sai_entries, se_list) {
if (se->se_index < entry->se_index) {
pos = &se->se_list;
}
}
list_add(&entry->se_list, pos);
+ entry->se_state = ret < 0 ? SA_ENTRY_INVA : SA_ENTRY_SUCC;
- return (entry->se_index == sai->sai_index_wait);
+ return (index == sai->sai_index_wait);
}
-/* release resources used in async stat RPC, complete entry information and
- * wakeup if necessary */
+/*
+ * release resources used in async stat RPC, update entry state and wakeup if
+ * scanner process it waiting on this entry.
+ */
static void
sa_make_ready(struct ll_statahead_info *sai, struct sa_entry *entry, int ret)
{
- struct ll_inode_info *lli = ll_i2info(sai->sai_inode);
+ struct ll_inode_info *lli = ll_i2info(sai->sai_dentry->d_inode);
struct md_enqueue_info *minfo = entry->se_minfo;
struct ptlrpc_request *req = entry->se_req;
bool wakeup;
wake_up(&sai->sai_waitq);
}
-/*
- * Insert inode into the list of sai_agls.
- */
+/* insert inode into the list of sai_agls */
static void ll_agl_add(struct ll_statahead_info *sai,
struct inode *inode, int index)
{
struct ll_inode_info *child = ll_i2info(inode);
- struct ll_inode_info *parent = ll_i2info(sai->sai_inode);
+ struct ll_inode_info *parent = ll_i2info(sai->sai_dentry->d_inode);
int added = 0;
spin_lock(&child->lli_agl_lock);
wake_up(&sai->sai_agl_thread.t_ctl_waitq);
}
-static struct ll_statahead_info *ll_sai_alloc(void)
+/* allocate sai */
+static struct ll_statahead_info *ll_sai_alloc(struct dentry *dentry)
{
struct ll_statahead_info *sai;
- int i;
+ struct ll_inode_info *lli = ll_i2info(dentry->d_inode);
+ int i;
ENTRY;
OBD_ALLOC_PTR(sai);
if (!sai)
RETURN(NULL);
+ sai->sai_dentry = dget(dentry);
atomic_set(&sai->sai_refcount, 1);
-
- spin_lock(&sai_generation_lock);
- sai->sai_generation = ++sai_generation;
- if (unlikely(sai_generation == 0))
- sai->sai_generation = ++sai_generation;
- spin_unlock(&sai_generation_lock);
-
sai->sai_max = LL_SA_RPC_MIN;
sai->sai_index = 1;
init_waitqueue_head(&sai->sai_waitq);
}
atomic_set(&sai->sai_cache_count, 0);
+ spin_lock(&sai_generation_lock);
+ lli->lli_sa_generation = ++sai_generation;
+ if (unlikely(sai_generation == 0))
+ lli->lli_sa_generation = ++sai_generation;
+ spin_unlock(&sai_generation_lock);
+
RETURN(sai);
}
+/* free sai */
+static inline void ll_sai_free(struct ll_statahead_info *sai)
+{
+ LASSERT(sai->sai_dentry != NULL);
+ dput(sai->sai_dentry);
+ OBD_FREE_PTR(sai);
+}
+
+/*
+ * take refcount of sai if sai for @dir exists, which means statahead is on for
+ * this directory.
+ */
static inline struct ll_statahead_info *ll_sai_get(struct inode *dir)
{
struct ll_inode_info *lli = ll_i2info(dir);
return sai;
}
+/*
+ * put sai refcount after use, if refcount reaches zero, free sai and sa_entries
+ * attached to it.
+ */
static void ll_sai_put(struct ll_statahead_info *sai)
{
- struct ll_inode_info *lli = ll_i2info(sai->sai_inode);
+ struct ll_inode_info *lli = ll_i2info(sai->sai_dentry->d_inode);
if (atomic_dec_and_lock(&sai->sai_refcount, &lli->lli_sa_lock)) {
struct sa_entry *entry, *next;
- struct ll_sb_info *sbi = ll_i2sbi(sai->sai_inode);
+ struct ll_sb_info *sbi = ll_i2sbi(sai->sai_dentry->d_inode);
lli->lli_sai = NULL;
spin_unlock(&lli->lli_sa_lock);
LASSERT(atomic_read(&sai->sai_cache_count) == 0);
LASSERT(agl_list_empty(sai));
- iput(sai->sai_inode);
- OBD_FREE_PTR(sai);
+ ll_sai_free(sai);
atomic_dec(&sbi->ll_sa_running);
}
}
EXIT;
}
-/* prepare inode for sa entry, add it into agl list, now sa_entry is ready
- * to be used by scanner process. */
+/*
+ * prepare inode for sa entry, add it into agl list, now sa_entry is ready
+ * to be used by scanner process.
+ */
static void sa_instantiate(struct ll_statahead_info *sai,
struct sa_entry *entry)
{
- struct inode *dir = sai->sai_inode;
+ struct inode *dir = sai->sai_dentry->d_inode;
struct inode *child;
struct md_enqueue_info *minfo;
struct lookup_intent *it;
if (body == NULL)
GOTO(out, rc = -EFAULT);
- child = entry->se_inode;
- if (child == NULL) {
- /*
- * lookup.
- */
- LASSERT(fid_is_zero(&minfo->mi_data.op_fid2));
-
- /* XXX: No fid in reply, this is probaly cross-ref case.
- * SA can't handle it yet. */
- if (body->mbo_valid & OBD_MD_MDS)
- GOTO(out, rc = -EAGAIN);
- } else {
- /*
- * revalidate.
- */
- /* unlinked and re-created with the same name */
+ child = entry->se_inode;
+ if (child != NULL) {
+ /* revalidate; unlinked and re-created with the same name */
if (unlikely(!lu_fid_eq(&minfo->mi_data.op_fid2,
&body->mbo_fid1))) {
- entry->se_inode = NULL;
- iput(child);
- child = NULL;
- }
- }
+ entry->se_inode = NULL;
+ iput(child);
+ child = NULL;
+ }
+ }
it->d.lustre.it_lock_handle = entry->se_handle;
rc = md_revalidate_lock(ll_i2mdexp(dir), it, ll_inode2fid(dir), NULL);
sa_make_ready(sai, entry, rc);
}
-/* once there are async stat replies, instantiate sa_entry */
+/* once there are async stat replies, instantiate sa_entry from replies */
static void sa_handle_callback(struct ll_statahead_info *sai)
{
struct ll_inode_info *lli;
- lli = ll_i2info(sai->sai_inode);
+ lli = ll_i2info(sai->sai_dentry->d_inode);
while (sa_has_callback(sai)) {
struct sa_entry *entry;
sa_instantiate(sai, entry);
}
-
- spin_lock(&lli->lli_agl_lock);
- while (!agl_list_empty(sai)) {
- struct ll_inode_info *clli;
-
- 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);
}
-/* callback for async stat, because this is called in ptlrpcd context, we only
- * put sa_entry in sai_cb_entries list, and let sa_handle_callback() to really
- * prepare inode and instantiate sa_entry later. */
+/*
+ * callback for async stat RPC, because this is called in ptlrpcd context, we
+ * only put sa_entry in sai_interim_entries, and wake up statahead thread to
+ * really prepare inode and instantiate sa_entry later.
+ */
static int ll_statahead_interpret(struct ptlrpc_request *req,
struct md_enqueue_info *minfo, int rc)
{
struct ll_statahead_info *sai = lli->lli_sai;
struct sa_entry *entry = (struct sa_entry *)minfo->mi_cbdata;
__u64 handle = 0;
- bool wakeup;
+ wait_queue_head_t *waitq = NULL;
ENTRY;
if (it_disposition(it, DISP_LOOKUP_NEG))
spin_lock(&lli->lli_sa_lock);
if (rc != 0) {
- wakeup = __sa_make_ready(sai, entry, rc);
+ if (__sa_make_ready(sai, entry, rc))
+ waitq = &sai->sai_waitq;
} else {
entry->se_minfo = minfo;
entry->se_req = ptlrpc_request_addref(req);
* for readpage and other tries to enqueue lock on child
* with parent's lock held, for example: unlink. */
entry->se_handle = handle;
- wakeup = !sa_has_callback(sai);
+ if (!sa_has_callback(sai))
+ waitq = &sai->sai_thread.t_ctl_waitq;
+
list_add_tail(&entry->se_list, &sai->sai_interim_entries);
}
sai->sai_replied++;
- if (wakeup)
- wake_up(&sai->sai_thread.t_ctl_waitq);
+ if (waitq != NULL)
+ wake_up(waitq);
spin_unlock(&lli->lli_sa_lock);
RETURN(rc);
}
-static void sa_fini_data(struct md_enqueue_info *minfo,
- struct ldlm_enqueue_info *einfo)
+/* finish async stat RPC arguments */
+static void sa_fini_data(struct md_enqueue_info *minfo)
{
- LASSERT(minfo && einfo);
iput(minfo->mi_dir);
- capa_put(minfo->mi_data.op_capa1);
- capa_put(minfo->mi_data.op_capa2);
OBD_FREE_PTR(minfo);
- OBD_FREE_PTR(einfo);
}
-/**
- * There is race condition between "capa_put" and "ll_statahead_interpret" for
- * accessing "op_data.op_capa[1,2]" as following:
- * "capa_put" releases "op_data.op_capa[1,2]"'s reference count after calling
- * "md_intent_getattr_async". But "ll_statahead_interpret" maybe run first, and
- * fill "op_data.op_capa[1,2]" as POISON, then cause "capa_put" access invalid
- * "ocapa". So here reserve "op_data.op_capa[1,2]" in "pcapa" before calling
- * "md_intent_getattr_async".
+/*
+ * prepare arguments for async stat RPC.
*/
-static int sa_prep_data(struct inode *dir, struct inode *child,
- struct sa_entry *entry, struct md_enqueue_info **pmi,
- struct ldlm_enqueue_info **pei,
- struct obd_capa **pcapa)
+static struct md_enqueue_info *
+sa_prep_data(struct inode *dir, struct inode *child, struct sa_entry *entry)
{
- struct qstr *qstr = &entry->se_qstr;
- struct md_enqueue_info *minfo;
- struct ldlm_enqueue_info *einfo;
- struct md_op_data *op_data;
-
- OBD_ALLOC_PTR(einfo);
- if (einfo == NULL)
- return -ENOMEM;
-
- OBD_ALLOC_PTR(minfo);
- if (minfo == NULL) {
- OBD_FREE_PTR(einfo);
- return -ENOMEM;
- }
+ struct md_enqueue_info *minfo;
+ struct ldlm_enqueue_info *einfo;
+ struct md_op_data *op_data;
- op_data = ll_prep_md_op_data(&minfo->mi_data, dir, child, qstr->name,
- qstr->len, 0, LUSTRE_OPC_ANY, NULL);
- if (IS_ERR(op_data)) {
- OBD_FREE_PTR(einfo);
- OBD_FREE_PTR(minfo);
- return PTR_ERR(op_data);
- }
+ OBD_ALLOC_PTR(minfo);
+ if (minfo == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ op_data = ll_prep_md_op_data(&minfo->mi_data, dir, child, NULL, 0, 0,
+ LUSTRE_OPC_ANY, NULL);
+ if (IS_ERR(op_data)) {
+ OBD_FREE_PTR(minfo);
+ return (struct md_enqueue_info *)op_data;
+ }
+
+ if (child == NULL)
+ op_data->op_fid2 = entry->se_fid;
minfo->mi_it.it_op = IT_GETATTR;
minfo->mi_dir = igrab(dir);
minfo->mi_cb = ll_statahead_interpret;
minfo->mi_cbdata = entry;
- einfo->ei_type = LDLM_IBITS;
- einfo->ei_mode = it_to_lock_mode(&minfo->mi_it);
- einfo->ei_cb_bl = ll_md_blocking_ast;
- einfo->ei_cb_cp = ldlm_completion_ast;
- einfo->ei_cb_gl = NULL;
- einfo->ei_cbdata = NULL;
-
- *pmi = minfo;
- *pei = einfo;
- pcapa[0] = op_data->op_capa1;
- pcapa[1] = op_data->op_capa2;
+ einfo = &minfo->mi_einfo;
+ einfo->ei_type = LDLM_IBITS;
+ einfo->ei_mode = it_to_lock_mode(&minfo->mi_it);
+ einfo->ei_cb_bl = ll_md_blocking_ast;
+ einfo->ei_cb_cp = ldlm_completion_ast;
+ einfo->ei_cb_gl = NULL;
+ einfo->ei_cbdata = NULL;
- return 0;
+ return minfo;
}
+/* async stat for file not found in dcache */
static int sa_lookup(struct inode *dir, struct sa_entry *entry)
{
struct md_enqueue_info *minfo;
- struct ldlm_enqueue_info *einfo;
- struct obd_capa *capas[2];
int rc;
ENTRY;
- rc = sa_prep_data(dir, NULL, entry, &minfo, &einfo, capas);
- if (rc)
- RETURN(rc);
+ minfo = sa_prep_data(dir, NULL, entry);
+ if (IS_ERR(minfo))
+ RETURN(PTR_ERR(minfo));
- rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo, einfo);
- if (!rc) {
- capa_put(capas[0]);
- capa_put(capas[1]);
- } else {
- sa_fini_data(minfo, einfo);
- }
+ rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo);
+ if (rc < 0)
+ sa_fini_data(minfo);
RETURN(rc);
}
/**
- * similar to ll_revalidate_it().
- * \retval 1 -- dentry valid
- * \retval 0 -- will send stat-ahead request
- * \retval others -- prepare stat-ahead request failed
+ * async stat for file found in dcache, similar to .revalidate
+ *
+ * \retval 1 dentry valid, no RPC sent
+ * \retval 0 dentry invalid, will send async stat RPC
+ * \retval negative number upon error
*/
static int sa_revalidate(struct inode *dir, struct sa_entry *entry,
struct dentry *dentry)
struct lookup_intent it = { .it_op = IT_GETATTR,
.d.lustre.it_lock_handle = 0 };
struct md_enqueue_info *minfo;
- struct ldlm_enqueue_info *einfo;
- struct obd_capa *capas[2];
int rc;
ENTRY;
RETURN(1);
}
- rc = sa_prep_data(dir, inode, entry, &minfo, &einfo, capas);
- if (rc) {
+ minfo = sa_prep_data(dir, inode, entry);
+ if (IS_ERR(minfo)) {
entry->se_inode = NULL;
iput(inode);
- RETURN(rc);
+ RETURN(PTR_ERR(minfo));
}
- rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo, einfo);
- if (!rc) {
- capa_put(capas[0]);
- capa_put(capas[1]);
- } else {
+ rc = md_intent_getattr_async(ll_i2mdexp(dir), minfo);
+ if (rc < 0) {
entry->se_inode = NULL;
iput(inode);
- sa_fini_data(minfo, einfo);
+ sa_fini_data(minfo);
}
RETURN(rc);
}
-static void sa_statahead(struct dentry *parent, const char *name, int len)
+/* async stat for file with @name */
+static void sa_statahead(struct dentry *parent, const char *name, int len,
+ const struct lu_fid *fid)
{
struct inode *dir = parent->d_inode;
struct ll_inode_info *lli = ll_i2info(dir);
int rc;
ENTRY;
- entry = sa_alloc(sai, sai->sai_index, name, len);
+ entry = sa_alloc(sai, sai->sai_index, name, len, fid);
if (IS_ERR(entry))
RETURN_EXIT;
EXIT;
}
+/* async glimpse (agl) thread main function */
static int ll_agl_thread(void *arg)
{
struct dentry *parent = (struct dentry *)arg;
RETURN(0);
}
+/* start agl thread */
static void ll_start_agl(struct dentry *parent, struct ll_statahead_info *sai)
{
struct ptlrpc_thread *thread = &sai->sai_agl_thread;
EXIT;
}
+/* statahead thread main function */
static int ll_statahead_thread(void *arg)
{
struct dentry *parent = (struct dentry *)arg;
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 *sa_thread;
struct ptlrpc_thread *agl_thread;
int first = 0;
struct md_op_data *op_data;
ENTRY;
sai = ll_sai_get(dir);
- thread = &sai->sai_thread;
+ sa_thread = &sai->sai_thread;
agl_thread = &sai->sai_agl_thread;
- thread->t_pid = current_pid();
+ sa_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);
atomic_inc(&sbi->ll_sa_total);
spin_lock(&lli->lli_sa_lock);
- if (thread_is_init(thread))
+ if (thread_is_init(sa_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);
+ thread_set_flags(sa_thread, SVC_RUNNING);
spin_unlock(&lli->lli_sa_lock);
- wake_up(&thread->t_ctl_waitq);
+ wake_up(&sa_thread->t_ctl_waitq);
ll_dir_chain_init(&chain);
- while (pos != MDS_DIR_END_OFF && thread_is_running(thread)) {
+ while (pos != MDS_DIR_END_OFF && thread_is_running(sa_thread)) {
struct lu_dirpage *dp;
struct lu_dirent *ent;
dp = page_address(page);
for (ent = lu_dirent_start(dp);
- ent != NULL && thread_is_running(thread) &&
+ ent != NULL && thread_is_running(sa_thread) &&
!sa_low_hit(sai);
ent = lu_dirent_next(ent)) {
__u64 hash;
int namelen;
char *name;
+ struct lu_fid fid;
hash = le64_to_cpu(ent->lde_hash);
if (unlikely(hash < pos))
if (unlikely(++first == 1))
continue;
+ fid_le_to_cpu(&fid, &ent->lde_fid);
+
/* wait for spare statahead window */
do {
- l_wait_event(thread->t_ctl_waitq,
+ l_wait_event(sa_thread->t_ctl_waitq,
!sa_sent_full(sai) ||
sa_has_callback(sai) ||
!agl_list_empty(sai) ||
- !thread_is_running(thread),
+ !thread_is_running(sa_thread),
&lwi);
sa_handle_callback(sai);
+
+ spin_lock(&lli->lli_agl_lock);
+ while (sa_sent_full(sai) &&
+ !agl_list_empty(sai)) {
+ struct ll_inode_info *clli;
+
+ 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);
} while (sa_sent_full(sai) &&
- thread_is_running(thread));
+ thread_is_running(sa_thread));
- sa_statahead(parent, name, namelen);
+ sa_statahead(parent, name, namelen, &fid);
}
pos = le64_to_cpu(dp->ldp_hash_end);
if (rc < 0) {
spin_lock(&lli->lli_sa_lock);
- thread_set_flags(thread, SVC_STOPPING);
+ thread_set_flags(sa_thread, SVC_STOPPING);
lli->lli_sa_enabled = 0;
spin_unlock(&lli->lli_sa_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,
+ while (thread_is_running(sa_thread)) {
+ l_wait_event(sa_thread->t_ctl_waitq,
sa_has_callback(sai) ||
- !agl_list_empty(sai) ||
- !thread_is_running(thread),
+ !thread_is_running(sa_thread),
&lwi);
sa_handle_callback(sai);
/* in case we're not woken up, timeout wait */
lwi = LWI_TIMEOUT(msecs_to_jiffies(MSEC_PER_SEC >> 3),
NULL, NULL);
- l_wait_event(thread->t_ctl_waitq,
+ l_wait_event(sa_thread->t_ctl_waitq,
sai->sai_sent == sai->sai_replied, &lwi);
}
sa_handle_callback(sai);
spin_lock(&lli->lli_sa_lock);
- thread_set_flags(thread, SVC_STOPPED);
+ thread_set_flags(sa_thread, SVC_STOPPED);
spin_unlock(&lli->lli_sa_lock);
- wake_up(&sai->sai_waitq);
- wake_up(&thread->t_ctl_waitq);
- ll_sai_put(sai);
CDEBUG(D_READA, "statahead thread stopped: sai %p, parent %.*s\n",
sai, parent->d_name.len, parent->d_name.name);
- dput(parent);
+
+ wake_up(&sai->sai_waitq);
+ wake_up(&sa_thread->t_ctl_waitq);
+ ll_sai_put(sai);
+
return rc;
}
-/* authorize opened dir handle @key to statahead later */
+/* authorize opened dir handle @key to statahead */
void ll_authorize_statahead(struct inode *dir, void *key)
{
struct ll_inode_info *lli = ll_i2info(dir);
spin_unlock(&lli->lli_sa_lock);
}
-/* deauthorize opened dir handle @key to statahead, but statahead thread may
- * still be running, notify it to quit. */
+/*
+ * deauthorize opened dir handle @key to statahead, and notify statahead thread
+ * to quit if it's running.
+ */
void ll_deauthorize_statahead(struct inode *dir, void *key)
{
struct ll_inode_info *lli = ll_i2info(dir);
}
enum {
- /**
- * not first dirent, or is "."
- */
- LS_NONE_FIRST_DE = 0,
- /**
- * the first non-hidden dirent
- */
- LS_FIRST_DE,
- /**
- * the first hidden dirent, that is "."
- */
- LS_FIRST_DOT_DE
+ /**
+ * not first dirent, or is "."
+ */
+ LS_NOT_FIRST_DE = 0,
+ /**
+ * the first non-hidden dirent
+ */
+ LS_FIRST_DE,
+ /**
+ * the first hidden dirent, that is "."
+ */
+ LS_FIRST_DOT_DE
};
+/* file is first dirent under @dir */
static int is_first_dirent(struct inode *dir, struct dentry *dentry)
{
struct ll_dir_chain chain;
struct md_op_data *op_data;
int dot_de;
struct page *page = NULL;
- int rc = LS_NONE_FIRST_DE;
+ int rc = LS_NOT_FIRST_DE;
__u64 pos = 0;
ENTRY;
if (target->len != namelen ||
memcmp(target->name, name, namelen) != 0)
- rc = LS_NONE_FIRST_DE;
+ rc = LS_NOT_FIRST_DE;
else if (!dot_de)
rc = LS_FIRST_DE;
else
return rc;
}
+/**
+ * revalidate @dentryp from statahead cache
+ *
+ * \param[in] dir parent directory
+ * \param[in] sai sai structure
+ * \param[out] dentryp pointer to dentry which will be revalidated
+ * \param[in] unplug unplug statahead window only (normally for negative
+ * dentry)
+ * \retval 1 on success, dentry is saved in @dentryp
+ * \retval 0 if revalidation failed (no proper lock on client)
+ * \retval negative number upon error
+ */
static int revalidate_statahead_dentry(struct inode *dir,
struct ll_statahead_info *sai,
struct dentry **dentryp,
- int only_unplug)
+ bool unplug)
{
struct sa_entry *entry = NULL;
struct l_wait_info lwi = { 0 };
+ struct ll_dentry_data *ldd;
+ struct ll_inode_info *lli = ll_i2info(dir);
int rc = 0;
ENTRY;
}
}
+ if (unplug)
+ GOTO(out, rc = 1);
+
entry = sa_get(sai, &(*dentryp)->d_name);
- if (entry == NULL || only_unplug) {
- sa_put(sai, entry);
- RETURN(entry ? 1 : -EAGAIN);
- }
+ if (entry == NULL)
+ GOTO(out, rc = -EAGAIN);
/* if statahead is busy in readdir, help it do post-work */
if (!sa_ready(entry) && sai->sai_in_readpage)
sa_handle_callback(sai);
if (!sa_ready(entry)) {
+ spin_lock(&lli->lli_sa_lock);
sai->sai_index_wait = entry->se_index;
+ spin_unlock(&lli->lli_sa_lock);
lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(30), NULL,
- LWI_ON_SIGNAL_NOOP, NULL);
- rc = l_wait_event(sai->sai_waitq,
- sa_ready(entry) ||
- thread_is_stopped(&sai->sai_thread),
- &lwi);
+ LWI_ON_SIGNAL_NOOP, NULL);
+ rc = l_wait_event(sai->sai_waitq, sa_ready(entry), &lwi);
if (rc < 0) {
- sa_put(sai, entry);
- RETURN(-EAGAIN);
+ /*
+ * entry may not be ready, so it may be used by inflight
+ * statahead RPC, don't free it.
+ */
+ entry = NULL;
+ GOTO(out, rc = -EAGAIN);
}
}
alias = ll_splice_alias(inode, *dentryp);
if (IS_ERR(alias)) {
- sa_put(sai, entry);
- RETURN(PTR_ERR(alias));
+ ll_intent_release(&it);
+ GOTO(out, rc = PTR_ERR(alias));
}
*dentryp = alias;
+ /* statahead prepared this inode, transfer inode
+ * refcount from sa_entry to dentry */
+ entry->se_inode = NULL;
} else if ((*dentryp)->d_inode != inode) {
/* revalidate, but inode is recreated */
CDEBUG(D_READA,
(*dentryp)->d_name.name,
PFID(ll_inode2fid((*dentryp)->d_inode)),
PFID(ll_inode2fid(inode)));
- sa_put(sai, entry);
- RETURN(-ESTALE);
- } else {
- iput(inode);
+ ll_intent_release(&it);
+ GOTO(out, rc = -ESTALE);
}
- entry->se_inode = NULL;
if ((bits & MDS_INODELOCK_LOOKUP) &&
d_lustre_invalid(*dentryp))
ll_intent_release(&it);
}
}
-
+out:
+ /*
+ * statahead cached sa_entry can be used only once, and will be killed
+ * right after use, so if lookup/revalidate accessed statahead cache,
+ * set dentry ldd_sa_generation to parent lli_sa_generation, later if we
+ * stat this file again, we know we've done statahead before, see
+ * dentry_may_statahead().
+ */
+ ldd = ll_d2d(*dentryp);
+ /* ldd can be NULL if llite lookup failed. */
+ if (ldd != NULL)
+ ldd->lld_sa_generation = lli->lli_sa_generation;
sa_put(sai, entry);
+
RETURN(rc);
}
+/**
+ * start statahead thread
+ *
+ * \param[in] dir parent directory
+ * \param[in] dentry dentry that triggers statahead, normally the first
+ * dirent under @dir
+ * \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)
{
struct ll_inode_info *lli = ll_i2info(dir);
struct ll_statahead_info *sai = NULL;
- struct dentry *parent;
+ struct dentry *parent = dentry->d_parent;
struct ptlrpc_thread *thread;
struct l_wait_info lwi = { 0 };
struct task_struct *task;
/* 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)
+ if (rc == LS_NOT_FIRST_DE)
/* It is not "ls -{a}l" operation, no need statahead for it. */
- GOTO(out, rc = -EAGAIN);
+ GOTO(out, rc = -EFAULT);
- sai = ll_sai_alloc();
+ sai = ll_sai_alloc(parent);
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);
- }
- /* 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);
-
- 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);
-
- /* if another process started statahead thread, or deauthorized current
- * lli_opendir_key, don't start statahead. */
+ /* if current lli_opendir_key was deauthorized, or dir re-opened by
+ * another process, don't start statahead, otherwise the newly spawned
+ * statahead thread won't be notified to quit. */
spin_lock(&lli->lli_sa_lock);
if (unlikely(lli->lli_sai != NULL ||
lli->lli_opendir_key == NULL ||
lli->lli_opendir_pid != current->pid)) {
spin_unlock(&lli->lli_sa_lock);
-
- dput(parent);
- iput(sai->sai_inode);
- GOTO(out, rc = -EAGAIN);
+ GOTO(out, rc = -EPERM);
}
lli->lli_sai = sai;
spin_unlock(&lli->lli_sa_lock);
atomic_inc(&ll_i2sbi(parent->d_inode)->ll_sa_running);
+ CDEBUG(D_READA, "start statahead thread: [pid %d] [parent %.*s]\n",
+ current_pid(), parent->d_name.len, parent->d_name.name);
+
task = kthread_run(ll_statahead_thread, parent, "ll_sa_%u",
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);
-
- 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 == NULL);
- RETURN(-EAGAIN);
+ CERROR("can't start ll_sa thread, rc: %d\n", rc);
+ GOTO(out, rc);
}
l_wait_event(thread->t_ctl_waitq,
RETURN(-EAGAIN);
out:
- if (sai != NULL)
- OBD_FREE_PTR(sai);
-
- /* once we start statahead thread failed, disable statahead so
- * subsequent won't waste time to try it. */
+ /* once we start statahead thread failed, disable statahead so that
+ * subsequent stat won't waste time to try it. */
spin_lock(&lli->lli_sa_lock);
lli->lli_sa_enabled = 0;
+ lli->lli_sai = NULL;
spin_unlock(&lli->lli_sa_lock);
+ if (sai != NULL)
+ ll_sai_free(sai);
+
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.
+ * 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
+ * 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
+ * \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 do_statahead_enter(struct inode *dir, struct dentry **dentryp,
- int only_unplug)
+int ll_statahead(struct inode *dir, struct dentry **dentryp, bool unplug)
{
struct ll_statahead_info *sai;
if (sai != NULL) {
int rc;
- rc = revalidate_statahead_dentry(dir, sai, dentryp,
- only_unplug);
+ rc = revalidate_statahead_dentry(dir, sai, dentryp, 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 / blobdiff