--- /dev/null
+/* -*- mode: c; c-basic-offset: 8; -*-
+ * vim: noexpandtab sw=8 ts=8 sts=0:
+ *
+ * dlmglue.c
+ *
+ * Code which implements an OCFS2 specific interface to our DLM.
+ *
+ * Copyright (C) 2003, 2004 Oracle. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public
+ * License along with this program; if not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 021110-1307, USA.
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+#include <linux/mm.h>
+#include <linux/kthread.h>
+#include <linux/pagemap.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/time.h>
+#include <linux/quotaops.h>
+
+#define MLOG_MASK_PREFIX ML_DLM_GLUE
+#include <cluster/masklog.h>
+
+#include "ocfs2.h"
+#include "ocfs2_lockingver.h"
+
+#include "alloc.h"
+#include "dcache.h"
+#include "dlmglue.h"
+#include "extent_map.h"
+#include "file.h"
+#include "heartbeat.h"
+#include "inode.h"
+#include "journal.h"
+#include "stackglue.h"
+#include "slot_map.h"
+#include "super.h"
+#include "uptodate.h"
+#include "quota.h"
+#include "refcounttree.h"
+
+#include "buffer_head_io.h"
+
+struct ocfs2_mask_waiter {
+ struct list_head mw_item;
+ int mw_status;
+ struct completion mw_complete;
+ unsigned long mw_mask;
+ unsigned long mw_goal;
+#ifdef CONFIG_OCFS2_FS_STATS
+ ktime_t mw_lock_start;
+#endif
+};
+
+static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres);
+static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres);
+static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres);
+static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres);
+
+/*
+ * Return value from ->downconvert_worker functions.
+ *
+ * These control the precise actions of ocfs2_unblock_lock()
+ * and ocfs2_process_blocked_lock()
+ *
+ */
+enum ocfs2_unblock_action {
+ UNBLOCK_CONTINUE = 0, /* Continue downconvert */
+ UNBLOCK_CONTINUE_POST = 1, /* Continue downconvert, fire
+ * ->post_unlock callback */
+ UNBLOCK_STOP_POST = 2, /* Do not downconvert, fire
+ * ->post_unlock() callback. */
+};
+
+struct ocfs2_unblock_ctl {
+ int requeue;
+ enum ocfs2_unblock_action unblock_action;
+};
+
+/* Lockdep class keys */
+struct lock_class_key lockdep_keys[OCFS2_NUM_LOCK_TYPES];
+
+static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
+ int new_level);
+static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres);
+
+static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
+ int blocking);
+
+static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
+ int blocking);
+
+static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres);
+
+static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres);
+
+static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
+ int new_level);
+static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
+ int blocking);
+
+#define mlog_meta_lvb(__level, __lockres) ocfs2_dump_meta_lvb_info(__level, __PRETTY_FUNCTION__, __LINE__, __lockres)
+
+/* This aids in debugging situations where a bad LVB might be involved. */
+static void ocfs2_dump_meta_lvb_info(u64 level,
+ const char *function,
+ unsigned int line,
+ struct ocfs2_lock_res *lockres)
+{
+ struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+
+ mlog(level, "LVB information for %s (called from %s:%u):\n",
+ lockres->l_name, function, line);
+ mlog(level, "version: %u, clusters: %u, generation: 0x%x\n",
+ lvb->lvb_version, be32_to_cpu(lvb->lvb_iclusters),
+ be32_to_cpu(lvb->lvb_igeneration));
+ mlog(level, "size: %llu, uid %u, gid %u, mode 0x%x\n",
+ (unsigned long long)be64_to_cpu(lvb->lvb_isize),
+ be32_to_cpu(lvb->lvb_iuid), be32_to_cpu(lvb->lvb_igid),
+ be16_to_cpu(lvb->lvb_imode));
+ mlog(level, "nlink %u, atime_packed 0x%llx, ctime_packed 0x%llx, "
+ "mtime_packed 0x%llx iattr 0x%x\n", be16_to_cpu(lvb->lvb_inlink),
+ (long long)be64_to_cpu(lvb->lvb_iatime_packed),
+ (long long)be64_to_cpu(lvb->lvb_ictime_packed),
+ (long long)be64_to_cpu(lvb->lvb_imtime_packed),
+ be32_to_cpu(lvb->lvb_iattr));
+}
+
+
+/*
+ * OCFS2 Lock Resource Operations
+ *
+ * These fine tune the behavior of the generic dlmglue locking infrastructure.
+ *
+ * The most basic of lock types can point ->l_priv to their respective
+ * struct ocfs2_super and allow the default actions to manage things.
+ *
+ * Right now, each lock type also needs to implement an init function,
+ * and trivial lock/unlock wrappers. ocfs2_simple_drop_lockres()
+ * should be called when the lock is no longer needed (i.e., object
+ * destruction time).
+ */
+struct ocfs2_lock_res_ops {
+ /*
+ * Translate an ocfs2_lock_res * into an ocfs2_super *. Define
+ * this callback if ->l_priv is not an ocfs2_super pointer
+ */
+ struct ocfs2_super * (*get_osb)(struct ocfs2_lock_res *);
+
+ /*
+ * Optionally called in the downconvert thread after a
+ * successful downconvert. The lockres will not be referenced
+ * after this callback is called, so it is safe to free
+ * memory, etc.
+ *
+ * The exact semantics of when this is called are controlled
+ * by ->downconvert_worker()
+ */
+ void (*post_unlock)(struct ocfs2_super *, struct ocfs2_lock_res *);
+
+ /*
+ * Allow a lock type to add checks to determine whether it is
+ * safe to downconvert a lock. Return 0 to re-queue the
+ * downconvert at a later time, nonzero to continue.
+ *
+ * For most locks, the default checks that there are no
+ * incompatible holders are sufficient.
+ *
+ * Called with the lockres spinlock held.
+ */
+ int (*check_downconvert)(struct ocfs2_lock_res *, int);
+
+ /*
+ * Allows a lock type to populate the lock value block. This
+ * is called on downconvert, and when we drop a lock.
+ *
+ * Locks that want to use this should set LOCK_TYPE_USES_LVB
+ * in the flags field.
+ *
+ * Called with the lockres spinlock held.
+ */
+ void (*set_lvb)(struct ocfs2_lock_res *);
+
+ /*
+ * Called from the downconvert thread when it is determined
+ * that a lock will be downconverted. This is called without
+ * any locks held so the function can do work that might
+ * schedule (syncing out data, etc).
+ *
+ * This should return any one of the ocfs2_unblock_action
+ * values, depending on what it wants the thread to do.
+ */
+ int (*downconvert_worker)(struct ocfs2_lock_res *, int);
+
+ /*
+ * LOCK_TYPE_* flags which describe the specific requirements
+ * of a lock type. Descriptions of each individual flag follow.
+ */
+ int flags;
+};
+
+/*
+ * Some locks want to "refresh" potentially stale data when a
+ * meaningful (PRMODE or EXMODE) lock level is first obtained. If this
+ * flag is set, the OCFS2_LOCK_NEEDS_REFRESH flag will be set on the
+ * individual lockres l_flags member from the ast function. It is
+ * expected that the locking wrapper will clear the
+ * OCFS2_LOCK_NEEDS_REFRESH flag when done.
+ */
+#define LOCK_TYPE_REQUIRES_REFRESH 0x1
+
+/*
+ * Indicate that a lock type makes use of the lock value block. The
+ * ->set_lvb lock type callback must be defined.
+ */
+#define LOCK_TYPE_USES_LVB 0x2
+
+static struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = {
+ .get_osb = ocfs2_get_inode_osb,
+ .flags = 0,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_inode_inode_lops = {
+ .get_osb = ocfs2_get_inode_osb,
+ .check_downconvert = ocfs2_check_meta_downconvert,
+ .set_lvb = ocfs2_set_meta_lvb,
+ .downconvert_worker = ocfs2_data_convert_worker,
+ .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_super_lops = {
+ .flags = LOCK_TYPE_REQUIRES_REFRESH,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_rename_lops = {
+ .flags = 0,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = {
+ .flags = 0,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = {
+ .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_dentry_lops = {
+ .get_osb = ocfs2_get_dentry_osb,
+ .post_unlock = ocfs2_dentry_post_unlock,
+ .downconvert_worker = ocfs2_dentry_convert_worker,
+ .flags = 0,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_inode_open_lops = {
+ .get_osb = ocfs2_get_inode_osb,
+ .flags = 0,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_flock_lops = {
+ .get_osb = ocfs2_get_file_osb,
+ .flags = 0,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_qinfo_lops = {
+ .set_lvb = ocfs2_set_qinfo_lvb,
+ .get_osb = ocfs2_get_qinfo_osb,
+ .flags = LOCK_TYPE_REQUIRES_REFRESH | LOCK_TYPE_USES_LVB,
+};
+
+static struct ocfs2_lock_res_ops ocfs2_refcount_block_lops = {
+ .check_downconvert = ocfs2_check_refcount_downconvert,
+ .downconvert_worker = ocfs2_refcount_convert_worker,
+ .flags = 0,
+};
+
+static inline int ocfs2_is_inode_lock(struct ocfs2_lock_res *lockres)
+{
+ return lockres->l_type == OCFS2_LOCK_TYPE_META ||
+ lockres->l_type == OCFS2_LOCK_TYPE_RW ||
+ lockres->l_type == OCFS2_LOCK_TYPE_OPEN;
+}
+
+static inline struct ocfs2_lock_res *ocfs2_lksb_to_lock_res(struct ocfs2_dlm_lksb *lksb)
+{
+ return container_of(lksb, struct ocfs2_lock_res, l_lksb);
+}
+
+static inline struct inode *ocfs2_lock_res_inode(struct ocfs2_lock_res *lockres)
+{
+ BUG_ON(!ocfs2_is_inode_lock(lockres));
+
+ return (struct inode *) lockres->l_priv;
+}
+
+static inline struct ocfs2_dentry_lock *ocfs2_lock_res_dl(struct ocfs2_lock_res *lockres)
+{
+ BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_DENTRY);
+
+ return (struct ocfs2_dentry_lock *)lockres->l_priv;
+}
+
+static inline struct ocfs2_mem_dqinfo *ocfs2_lock_res_qinfo(struct ocfs2_lock_res *lockres)
+{
+ BUG_ON(lockres->l_type != OCFS2_LOCK_TYPE_QINFO);
+
+ return (struct ocfs2_mem_dqinfo *)lockres->l_priv;
+}
+
+static inline struct ocfs2_refcount_tree *
+ocfs2_lock_res_refcount_tree(struct ocfs2_lock_res *res)
+{
+ return container_of(res, struct ocfs2_refcount_tree, rf_lockres);
+}
+
+static inline struct ocfs2_super *ocfs2_get_lockres_osb(struct ocfs2_lock_res *lockres)
+{
+ if (lockres->l_ops->get_osb)
+ return lockres->l_ops->get_osb(lockres);
+
+ return (struct ocfs2_super *)lockres->l_priv;
+}
+
+static int ocfs2_lock_create(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ int level,
+ u32 dlm_flags);
+static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
+ int wanted);
+static void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ int level, unsigned long caller_ip);
+static inline void ocfs2_cluster_unlock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ int level)
+{
+ __ocfs2_cluster_unlock(osb, lockres, level, _RET_IP_);
+}
+
+static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres);
+static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres);
+static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres);
+static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level);
+static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres);
+static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
+ int convert);
+#define ocfs2_log_dlm_error(_func, _err, _lockres) do { \
+ if ((_lockres)->l_type != OCFS2_LOCK_TYPE_DENTRY) \
+ mlog(ML_ERROR, "DLM error %d while calling %s on resource %s\n", \
+ _err, _func, _lockres->l_name); \
+ else \
+ mlog(ML_ERROR, "DLM error %d while calling %s on resource %.*s%08x\n", \
+ _err, _func, OCFS2_DENTRY_LOCK_INO_START - 1, (_lockres)->l_name, \
+ (unsigned int)ocfs2_get_dentry_lock_ino(_lockres)); \
+} while (0)
+static int ocfs2_downconvert_thread(void *arg);
+static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres);
+static int ocfs2_inode_lock_update(struct inode *inode,
+ struct buffer_head **bh);
+static void ocfs2_drop_osb_locks(struct ocfs2_super *osb);
+static inline int ocfs2_highest_compat_lock_level(int level);
+static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
+ int new_level);
+static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ int new_level,
+ int lvb,
+ unsigned int generation);
+static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres);
+static int ocfs2_cancel_convert(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres);
+
+
+static void ocfs2_build_lock_name(enum ocfs2_lock_type type,
+ u64 blkno,
+ u32 generation,
+ char *name)
+{
+ int len;
+
+ BUG_ON(type >= OCFS2_NUM_LOCK_TYPES);
+
+ len = snprintf(name, OCFS2_LOCK_ID_MAX_LEN, "%c%s%016llx%08x",
+ ocfs2_lock_type_char(type), OCFS2_LOCK_ID_PAD,
+ (long long)blkno, generation);
+
+ BUG_ON(len != (OCFS2_LOCK_ID_MAX_LEN - 1));
+
+ mlog(0, "built lock resource with name: %s\n", name);
+}
+
+static DEFINE_SPINLOCK(ocfs2_dlm_tracking_lock);
+
+static void ocfs2_add_lockres_tracking(struct ocfs2_lock_res *res,
+ struct ocfs2_dlm_debug *dlm_debug)
+{
+ mlog(0, "Add tracking for lockres %s\n", res->l_name);
+
+ spin_lock(&ocfs2_dlm_tracking_lock);
+ list_add(&res->l_debug_list, &dlm_debug->d_lockres_tracking);
+ spin_unlock(&ocfs2_dlm_tracking_lock);
+}
+
+static void ocfs2_remove_lockres_tracking(struct ocfs2_lock_res *res)
+{
+ spin_lock(&ocfs2_dlm_tracking_lock);
+ if (!list_empty(&res->l_debug_list))
+ list_del_init(&res->l_debug_list);
+ spin_unlock(&ocfs2_dlm_tracking_lock);
+}
+
+#ifdef CONFIG_OCFS2_FS_STATS
+static void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
+{
+ res->l_lock_refresh = 0;
+ memset(&res->l_lock_prmode, 0, sizeof(struct ocfs2_lock_stats));
+ memset(&res->l_lock_exmode, 0, sizeof(struct ocfs2_lock_stats));
+}
+
+static void ocfs2_update_lock_stats(struct ocfs2_lock_res *res, int level,
+ struct ocfs2_mask_waiter *mw, int ret)
+{
+ u32 usec;
+ ktime_t kt;
+ struct ocfs2_lock_stats *stats;
+
+ if (level == LKM_PRMODE)
+ stats = &res->l_lock_prmode;
+ else if (level == LKM_EXMODE)
+ stats = &res->l_lock_exmode;
+ else
+ return;
+
+ kt = ktime_sub(ktime_get(), mw->mw_lock_start);
+ usec = ktime_to_us(kt);
+
+ stats->ls_gets++;
+ stats->ls_total += ktime_to_ns(kt);
+ /* overflow */
+ if (unlikely(stats->ls_gets == 0)) {
+ stats->ls_gets++;
+ stats->ls_total = ktime_to_ns(kt);
+ }
+
+ if (stats->ls_max < usec)
+ stats->ls_max = usec;
+
+ if (ret)
+ stats->ls_fail++;
+}
+
+static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
+{
+ lockres->l_lock_refresh++;
+}
+
+static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
+{
+ mw->mw_lock_start = ktime_get();
+}
+#else
+static inline void ocfs2_init_lock_stats(struct ocfs2_lock_res *res)
+{
+}
+static inline void ocfs2_update_lock_stats(struct ocfs2_lock_res *res,
+ int level, struct ocfs2_mask_waiter *mw, int ret)
+{
+}
+static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres)
+{
+}
+static inline void ocfs2_init_start_time(struct ocfs2_mask_waiter *mw)
+{
+}
+#endif
+
+static void ocfs2_lock_res_init_common(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *res,
+ enum ocfs2_lock_type type,
+ struct ocfs2_lock_res_ops *ops,
+ void *priv)
+{
+ res->l_type = type;
+ res->l_ops = ops;
+ res->l_priv = priv;
+
+ res->l_level = DLM_LOCK_IV;
+ res->l_requested = DLM_LOCK_IV;
+ res->l_blocking = DLM_LOCK_IV;
+ res->l_action = OCFS2_AST_INVALID;
+ res->l_unlock_action = OCFS2_UNLOCK_INVALID;
+
+ res->l_flags = OCFS2_LOCK_INITIALIZED;
+
+ ocfs2_add_lockres_tracking(res, osb->osb_dlm_debug);
+
+ ocfs2_init_lock_stats(res);
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ if (type != OCFS2_LOCK_TYPE_OPEN)
+ lockdep_init_map(&res->l_lockdep_map, ocfs2_lock_type_strings[type],
+ &lockdep_keys[type], 0);
+ else
+ res->l_lockdep_map.key = NULL;
+#endif
+}
+
+void ocfs2_lock_res_init_once(struct ocfs2_lock_res *res)
+{
+ /* This also clears out the lock status block */
+ memset(res, 0, sizeof(struct ocfs2_lock_res));
+ spin_lock_init(&res->l_lock);
+ init_waitqueue_head(&res->l_event);
+ INIT_LIST_HEAD(&res->l_blocked_list);
+ INIT_LIST_HEAD(&res->l_mask_waiters);
+}
+
+void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res,
+ enum ocfs2_lock_type type,
+ unsigned int generation,
+ struct inode *inode)
+{
+ struct ocfs2_lock_res_ops *ops;
+
+ switch(type) {
+ case OCFS2_LOCK_TYPE_RW:
+ ops = &ocfs2_inode_rw_lops;
+ break;
+ case OCFS2_LOCK_TYPE_META:
+ ops = &ocfs2_inode_inode_lops;
+ break;
+ case OCFS2_LOCK_TYPE_OPEN:
+ ops = &ocfs2_inode_open_lops;
+ break;
+ default:
+ mlog_bug_on_msg(1, "type: %d\n", type);
+ ops = NULL; /* thanks, gcc */
+ break;
+ };
+
+ ocfs2_build_lock_name(type, OCFS2_I(inode)->ip_blkno,
+ generation, res->l_name);
+ ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), res, type, ops, inode);
+}
+
+static struct ocfs2_super *ocfs2_get_inode_osb(struct ocfs2_lock_res *lockres)
+{
+ struct inode *inode = ocfs2_lock_res_inode(lockres);
+
+ return OCFS2_SB(inode->i_sb);
+}
+
+static struct ocfs2_super *ocfs2_get_qinfo_osb(struct ocfs2_lock_res *lockres)
+{
+ struct ocfs2_mem_dqinfo *info = lockres->l_priv;
+
+ return OCFS2_SB(info->dqi_gi.dqi_sb);
+}
+
+static struct ocfs2_super *ocfs2_get_file_osb(struct ocfs2_lock_res *lockres)
+{
+ struct ocfs2_file_private *fp = lockres->l_priv;
+
+ return OCFS2_SB(fp->fp_file->f_mapping->host->i_sb);
+}
+
+static __u64 ocfs2_get_dentry_lock_ino(struct ocfs2_lock_res *lockres)
+{
+ __be64 inode_blkno_be;
+
+ memcpy(&inode_blkno_be, &lockres->l_name[OCFS2_DENTRY_LOCK_INO_START],
+ sizeof(__be64));
+
+ return be64_to_cpu(inode_blkno_be);
+}
+
+static struct ocfs2_super *ocfs2_get_dentry_osb(struct ocfs2_lock_res *lockres)
+{
+ struct ocfs2_dentry_lock *dl = lockres->l_priv;
+
+ return OCFS2_SB(dl->dl_inode->i_sb);
+}
+
+void ocfs2_dentry_lock_res_init(struct ocfs2_dentry_lock *dl,
+ u64 parent, struct inode *inode)
+{
+ int len;
+ u64 inode_blkno = OCFS2_I(inode)->ip_blkno;
+ __be64 inode_blkno_be = cpu_to_be64(inode_blkno);
+ struct ocfs2_lock_res *lockres = &dl->dl_lockres;
+
+ ocfs2_lock_res_init_once(lockres);
+
+ /*
+ * Unfortunately, the standard lock naming scheme won't work
+ * here because we have two 16 byte values to use. Instead,
+ * we'll stuff the inode number as a binary value. We still
+ * want error prints to show something without garbling the
+ * display, so drop a null byte in there before the inode
+ * number. A future version of OCFS2 will likely use all
+ * binary lock names. The stringified names have been a
+ * tremendous aid in debugging, but now that the debugfs
+ * interface exists, we can mangle things there if need be.
+ *
+ * NOTE: We also drop the standard "pad" value (the total lock
+ * name size stays the same though - the last part is all
+ * zeros due to the memset in ocfs2_lock_res_init_once()
+ */
+ len = snprintf(lockres->l_name, OCFS2_DENTRY_LOCK_INO_START,
+ "%c%016llx",
+ ocfs2_lock_type_char(OCFS2_LOCK_TYPE_DENTRY),
+ (long long)parent);
+
+ BUG_ON(len != (OCFS2_DENTRY_LOCK_INO_START - 1));
+
+ memcpy(&lockres->l_name[OCFS2_DENTRY_LOCK_INO_START], &inode_blkno_be,
+ sizeof(__be64));
+
+ ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
+ OCFS2_LOCK_TYPE_DENTRY, &ocfs2_dentry_lops,
+ dl);
+}
+
+static void ocfs2_super_lock_res_init(struct ocfs2_lock_res *res,
+ struct ocfs2_super *osb)
+{
+ /* Superblock lockres doesn't come from a slab so we call init
+ * once on it manually. */
+ ocfs2_lock_res_init_once(res);
+ ocfs2_build_lock_name(OCFS2_LOCK_TYPE_SUPER, OCFS2_SUPER_BLOCK_BLKNO,
+ 0, res->l_name);
+ ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_SUPER,
+ &ocfs2_super_lops, osb);
+}
+
+static void ocfs2_rename_lock_res_init(struct ocfs2_lock_res *res,
+ struct ocfs2_super *osb)
+{
+ /* Rename lockres doesn't come from a slab so we call init
+ * once on it manually. */
+ ocfs2_lock_res_init_once(res);
+ ocfs2_build_lock_name(OCFS2_LOCK_TYPE_RENAME, 0, 0, res->l_name);
+ ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_RENAME,
+ &ocfs2_rename_lops, osb);
+}
+
+static void ocfs2_nfs_sync_lock_res_init(struct ocfs2_lock_res *res,
+ struct ocfs2_super *osb)
+{
+ /* nfs_sync lockres doesn't come from a slab so we call init
+ * once on it manually. */
+ ocfs2_lock_res_init_once(res);
+ ocfs2_build_lock_name(OCFS2_LOCK_TYPE_NFS_SYNC, 0, 0, res->l_name);
+ ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_NFS_SYNC,
+ &ocfs2_nfs_sync_lops, osb);
+}
+
+static void ocfs2_orphan_scan_lock_res_init(struct ocfs2_lock_res *res,
+ struct ocfs2_super *osb)
+{
+ ocfs2_lock_res_init_once(res);
+ ocfs2_build_lock_name(OCFS2_LOCK_TYPE_ORPHAN_SCAN, 0, 0, res->l_name);
+ ocfs2_lock_res_init_common(osb, res, OCFS2_LOCK_TYPE_ORPHAN_SCAN,
+ &ocfs2_orphan_scan_lops, osb);
+}
+
+void ocfs2_file_lock_res_init(struct ocfs2_lock_res *lockres,
+ struct ocfs2_file_private *fp)
+{
+ struct inode *inode = fp->fp_file->f_mapping->host;
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
+
+ ocfs2_lock_res_init_once(lockres);
+ ocfs2_build_lock_name(OCFS2_LOCK_TYPE_FLOCK, oi->ip_blkno,
+ inode->i_generation, lockres->l_name);
+ ocfs2_lock_res_init_common(OCFS2_SB(inode->i_sb), lockres,
+ OCFS2_LOCK_TYPE_FLOCK, &ocfs2_flock_lops,
+ fp);
+ lockres->l_flags |= OCFS2_LOCK_NOCACHE;
+}
+
+void ocfs2_qinfo_lock_res_init(struct ocfs2_lock_res *lockres,
+ struct ocfs2_mem_dqinfo *info)
+{
+ ocfs2_lock_res_init_once(lockres);
+ ocfs2_build_lock_name(OCFS2_LOCK_TYPE_QINFO, info->dqi_gi.dqi_type,
+ 0, lockres->l_name);
+ ocfs2_lock_res_init_common(OCFS2_SB(info->dqi_gi.dqi_sb), lockres,
+ OCFS2_LOCK_TYPE_QINFO, &ocfs2_qinfo_lops,
+ info);
+}
+
+void ocfs2_refcount_lock_res_init(struct ocfs2_lock_res *lockres,
+ struct ocfs2_super *osb, u64 ref_blkno,
+ unsigned int generation)
+{
+ ocfs2_lock_res_init_once(lockres);
+ ocfs2_build_lock_name(OCFS2_LOCK_TYPE_REFCOUNT, ref_blkno,
+ generation, lockres->l_name);
+ ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_REFCOUNT,
+ &ocfs2_refcount_block_lops, osb);
+}
+
+void ocfs2_lock_res_free(struct ocfs2_lock_res *res)
+{
+ if (!(res->l_flags & OCFS2_LOCK_INITIALIZED))
+ return;
+
+ ocfs2_remove_lockres_tracking(res);
+
+ mlog_bug_on_msg(!list_empty(&res->l_blocked_list),
+ "Lockres %s is on the blocked list\n",
+ res->l_name);
+ mlog_bug_on_msg(!list_empty(&res->l_mask_waiters),
+ "Lockres %s has mask waiters pending\n",
+ res->l_name);
+ mlog_bug_on_msg(spin_is_locked(&res->l_lock),
+ "Lockres %s is locked\n",
+ res->l_name);
+ mlog_bug_on_msg(res->l_ro_holders,
+ "Lockres %s has %u ro holders\n",
+ res->l_name, res->l_ro_holders);
+ mlog_bug_on_msg(res->l_ex_holders,
+ "Lockres %s has %u ex holders\n",
+ res->l_name, res->l_ex_holders);
+
+ /* Need to clear out the lock status block for the dlm */
+ memset(&res->l_lksb, 0, sizeof(res->l_lksb));
+
+ res->l_flags = 0UL;
+}
+
+static inline void ocfs2_inc_holders(struct ocfs2_lock_res *lockres,
+ int level)
+{
+ BUG_ON(!lockres);
+
+ switch(level) {
+ case DLM_LOCK_EX:
+ lockres->l_ex_holders++;
+ break;
+ case DLM_LOCK_PR:
+ lockres->l_ro_holders++;
+ break;
+ default:
+ BUG();
+ }
+}
+
+static inline void ocfs2_dec_holders(struct ocfs2_lock_res *lockres,
+ int level)
+{
+ BUG_ON(!lockres);
+
+ switch(level) {
+ case DLM_LOCK_EX:
+ BUG_ON(!lockres->l_ex_holders);
+ lockres->l_ex_holders--;
+ break;
+ case DLM_LOCK_PR:
+ BUG_ON(!lockres->l_ro_holders);
+ lockres->l_ro_holders--;
+ break;
+ default:
+ BUG();
+ }
+}
+
+/* WARNING: This function lives in a world where the only three lock
+ * levels are EX, PR, and NL. It *will* have to be adjusted when more
+ * lock types are added. */
+static inline int ocfs2_highest_compat_lock_level(int level)
+{
+ int new_level = DLM_LOCK_EX;
+
+ if (level == DLM_LOCK_EX)
+ new_level = DLM_LOCK_NL;
+ else if (level == DLM_LOCK_PR)
+ new_level = DLM_LOCK_PR;
+ return new_level;
+}
+
+static void lockres_set_flags(struct ocfs2_lock_res *lockres,
+ unsigned long newflags)
+{
+ struct ocfs2_mask_waiter *mw, *tmp;
+
+ assert_spin_locked(&lockres->l_lock);
+
+ lockres->l_flags = newflags;
+
+ list_for_each_entry_safe(mw, tmp, &lockres->l_mask_waiters, mw_item) {
+ if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
+ continue;
+
+ list_del_init(&mw->mw_item);
+ mw->mw_status = 0;
+ complete(&mw->mw_complete);
+ }
+}
+static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or)
+{
+ lockres_set_flags(lockres, lockres->l_flags | or);
+}
+static void lockres_clear_flags(struct ocfs2_lock_res *lockres,
+ unsigned long clear)
+{
+ lockres_set_flags(lockres, lockres->l_flags & ~clear);
+}
+
+static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres)
+{
+ BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
+ BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
+ BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
+ BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
+
+ lockres->l_level = lockres->l_requested;
+ if (lockres->l_level <=
+ ocfs2_highest_compat_lock_level(lockres->l_blocking)) {
+ lockres->l_blocking = DLM_LOCK_NL;
+ lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
+ }
+ lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+}
+
+static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres)
+{
+ BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
+ BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED));
+
+ /* Convert from RO to EX doesn't really need anything as our
+ * information is already up to data. Convert from NL to
+ * *anything* however should mark ourselves as needing an
+ * update */
+ if (lockres->l_level == DLM_LOCK_NL &&
+ lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
+ lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
+
+ lockres->l_level = lockres->l_requested;
+
+ /*
+ * We set the OCFS2_LOCK_UPCONVERT_FINISHING flag before clearing
+ * the OCFS2_LOCK_BUSY flag to prevent the dc thread from
+ * downconverting the lock before the upconvert has fully completed.
+ * Do not prevent the dc thread from downconverting if NONBLOCK lock
+ * had already returned.
+ */
+ if (!(lockres->l_flags & OCFS2_LOCK_NONBLOCK_FINISHED))
+ lockres_or_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
+ else
+ lockres_clear_flags(lockres, OCFS2_LOCK_NONBLOCK_FINISHED);
+
+ lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+}
+
+static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres)
+{
+ BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY)));
+ BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
+
+ if (lockres->l_requested > DLM_LOCK_NL &&
+ !(lockres->l_flags & OCFS2_LOCK_LOCAL) &&
+ lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
+ lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
+
+ lockres->l_level = lockres->l_requested;
+ lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED);
+ lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+}
+
+static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres,
+ int level)
+{
+ int needs_downconvert = 0;
+
+ assert_spin_locked(&lockres->l_lock);
+
+ if (level > lockres->l_blocking) {
+ /* only schedule a downconvert if we haven't already scheduled
+ * one that goes low enough to satisfy the level we're
+ * blocking. this also catches the case where we get
+ * duplicate BASTs */
+ if (ocfs2_highest_compat_lock_level(level) <
+ ocfs2_highest_compat_lock_level(lockres->l_blocking))
+ needs_downconvert = 1;
+
+ lockres->l_blocking = level;
+ }
+
+ mlog(ML_BASTS, "lockres %s, block %d, level %d, l_block %d, dwn %d\n",
+ lockres->l_name, level, lockres->l_level, lockres->l_blocking,
+ needs_downconvert);
+
+ if (needs_downconvert)
+ lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
+ mlog(0, "needs_downconvert = %d\n", needs_downconvert);
+ return needs_downconvert;
+}
+
+/*
+ * OCFS2_LOCK_PENDING and l_pending_gen.
+ *
+ * Why does OCFS2_LOCK_PENDING exist? To close a race between setting
+ * OCFS2_LOCK_BUSY and calling ocfs2_dlm_lock(). See ocfs2_unblock_lock()
+ * for more details on the race.
+ *
+ * OCFS2_LOCK_PENDING closes the race quite nicely. However, it introduces
+ * a race on itself. In o2dlm, we can get the ast before ocfs2_dlm_lock()
+ * returns. The ast clears OCFS2_LOCK_BUSY, and must therefore clear
+ * OCFS2_LOCK_PENDING at the same time. When ocfs2_dlm_lock() returns,
+ * the caller is going to try to clear PENDING again. If nothing else is
+ * happening, __lockres_clear_pending() sees PENDING is unset and does
+ * nothing.
+ *
+ * But what if another path (eg downconvert thread) has just started a
+ * new locking action? The other path has re-set PENDING. Our path
+ * cannot clear PENDING, because that will re-open the original race
+ * window.
+ *
+ * [Example]
+ *
+ * ocfs2_meta_lock()
+ * ocfs2_cluster_lock()
+ * set BUSY
+ * set PENDING
+ * drop l_lock
+ * ocfs2_dlm_lock()
+ * ocfs2_locking_ast() ocfs2_downconvert_thread()
+ * clear PENDING ocfs2_unblock_lock()
+ * take_l_lock
+ * !BUSY
+ * ocfs2_prepare_downconvert()
+ * set BUSY
+ * set PENDING
+ * drop l_lock
+ * take l_lock
+ * clear PENDING
+ * drop l_lock
+ * <window>
+ * ocfs2_dlm_lock()
+ *
+ * So as you can see, we now have a window where l_lock is not held,
+ * PENDING is not set, and ocfs2_dlm_lock() has not been called.
+ *
+ * The core problem is that ocfs2_cluster_lock() has cleared the PENDING
+ * set by ocfs2_prepare_downconvert(). That wasn't nice.
+ *
+ * To solve this we introduce l_pending_gen. A call to
+ * lockres_clear_pending() will only do so when it is passed a generation
+ * number that matches the lockres. lockres_set_pending() will return the
+ * current generation number. When ocfs2_cluster_lock() goes to clear
+ * PENDING, it passes the generation it got from set_pending(). In our
+ * example above, the generation numbers will *not* match. Thus,
+ * ocfs2_cluster_lock() will not clear the PENDING set by
+ * ocfs2_prepare_downconvert().
+ */
+
+/* Unlocked version for ocfs2_locking_ast() */
+static void __lockres_clear_pending(struct ocfs2_lock_res *lockres,
+ unsigned int generation,
+ struct ocfs2_super *osb)
+{
+ assert_spin_locked(&lockres->l_lock);
+
+ /*
+ * The ast and locking functions can race us here. The winner
+ * will clear pending, the loser will not.
+ */
+ if (!(lockres->l_flags & OCFS2_LOCK_PENDING) ||
+ (lockres->l_pending_gen != generation))
+ return;
+
+ lockres_clear_flags(lockres, OCFS2_LOCK_PENDING);
+ lockres->l_pending_gen++;
+
+ /*
+ * The downconvert thread may have skipped us because we
+ * were PENDING. Wake it up.
+ */
+ if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
+ ocfs2_wake_downconvert_thread(osb);
+}
+
+/* Locked version for callers of ocfs2_dlm_lock() */
+static void lockres_clear_pending(struct ocfs2_lock_res *lockres,
+ unsigned int generation,
+ struct ocfs2_super *osb)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ __lockres_clear_pending(lockres, generation, osb);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+}
+
+static unsigned int lockres_set_pending(struct ocfs2_lock_res *lockres)
+{
+ assert_spin_locked(&lockres->l_lock);
+ BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY));
+
+ lockres_or_flags(lockres, OCFS2_LOCK_PENDING);
+
+ return lockres->l_pending_gen;
+}
+
+static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level)
+{
+ struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
+ struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
+ int needs_downconvert;
+ unsigned long flags;
+
+ BUG_ON(level <= DLM_LOCK_NL);
+
+ mlog(ML_BASTS, "BAST fired for lockres %s, blocking %d, level %d, "
+ "type %s\n", lockres->l_name, level, lockres->l_level,
+ ocfs2_lock_type_string(lockres->l_type));
+
+ /*
+ * We can skip the bast for locks which don't enable caching -
+ * they'll be dropped at the earliest possible time anyway.
+ */
+ if (lockres->l_flags & OCFS2_LOCK_NOCACHE)
+ return;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ needs_downconvert = ocfs2_generic_handle_bast(lockres, level);
+ if (needs_downconvert)
+ ocfs2_schedule_blocked_lock(osb, lockres);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ wake_up(&lockres->l_event);
+
+ ocfs2_wake_downconvert_thread(osb);
+}
+
+static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb)
+{
+ struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
+ struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
+ unsigned long flags;
+ int status;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+
+ status = ocfs2_dlm_lock_status(&lockres->l_lksb);
+
+ if (status == -EAGAIN) {
+ lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+ goto out;
+ }
+
+ if (status) {
+ mlog(ML_ERROR, "lockres %s: lksb status value of %d!\n",
+ lockres->l_name, status);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ return;
+ }
+
+ mlog(ML_BASTS, "AST fired for lockres %s, action %d, unlock %d, "
+ "level %d => %d\n", lockres->l_name, lockres->l_action,
+ lockres->l_unlock_action, lockres->l_level, lockres->l_requested);
+
+ switch(lockres->l_action) {
+ case OCFS2_AST_ATTACH:
+ ocfs2_generic_handle_attach_action(lockres);
+ lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL);
+ break;
+ case OCFS2_AST_CONVERT:
+ ocfs2_generic_handle_convert_action(lockres);
+ break;
+ case OCFS2_AST_DOWNCONVERT:
+ ocfs2_generic_handle_downconvert_action(lockres);
+ break;
+ default:
+ mlog(ML_ERROR, "lockres %s: AST fired with invalid action: %u, "
+ "flags 0x%lx, unlock: %u\n",
+ lockres->l_name, lockres->l_action, lockres->l_flags,
+ lockres->l_unlock_action);
+ BUG();
+ }
+out:
+ /* set it to something invalid so if we get called again we
+ * can catch it. */
+ lockres->l_action = OCFS2_AST_INVALID;
+
+ /* Did we try to cancel this lock? Clear that state */
+ if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT)
+ lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
+
+ /*
+ * We may have beaten the locking functions here. We certainly
+ * know that dlm_lock() has been called :-)
+ * Because we can't have two lock calls in flight at once, we
+ * can use lockres->l_pending_gen.
+ */
+ __lockres_clear_pending(lockres, lockres->l_pending_gen, osb);
+
+ wake_up(&lockres->l_event);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+}
+
+static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error)
+{
+ struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb);
+ unsigned long flags;
+
+ mlog(ML_BASTS, "UNLOCK AST fired for lockres %s, action = %d\n",
+ lockres->l_name, lockres->l_unlock_action);
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ if (error) {
+ mlog(ML_ERROR, "Dlm passes error %d for lock %s, "
+ "unlock_action %d\n", error, lockres->l_name,
+ lockres->l_unlock_action);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ return;
+ }
+
+ switch(lockres->l_unlock_action) {
+ case OCFS2_UNLOCK_CANCEL_CONVERT:
+ mlog(0, "Cancel convert success for %s\n", lockres->l_name);
+ lockres->l_action = OCFS2_AST_INVALID;
+ /* Downconvert thread may have requeued this lock, we
+ * need to wake it. */
+ if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
+ ocfs2_wake_downconvert_thread(ocfs2_get_lockres_osb(lockres));
+ break;
+ case OCFS2_UNLOCK_DROP_LOCK:
+ lockres->l_level = DLM_LOCK_IV;
+ break;
+ default:
+ BUG();
+ }
+
+ lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+ lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
+ wake_up(&lockres->l_event);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+}
+
+/*
+ * This is the filesystem locking protocol. It provides the lock handling
+ * hooks for the underlying DLM. It has a maximum version number.
+ * The version number allows interoperability with systems running at
+ * the same major number and an equal or smaller minor number.
+ *
+ * Whenever the filesystem does new things with locks (adds or removes a
+ * lock, orders them differently, does different things underneath a lock),
+ * the version must be changed. The protocol is negotiated when joining
+ * the dlm domain. A node may join the domain if its major version is
+ * identical to all other nodes and its minor version is greater than
+ * or equal to all other nodes. When its minor version is greater than
+ * the other nodes, it will run at the minor version specified by the
+ * other nodes.
+ *
+ * If a locking change is made that will not be compatible with older
+ * versions, the major number must be increased and the minor version set
+ * to zero. If a change merely adds a behavior that can be disabled when
+ * speaking to older versions, the minor version must be increased. If a
+ * change adds a fully backwards compatible change (eg, LVB changes that
+ * are just ignored by older versions), the version does not need to be
+ * updated.
+ */
+static struct ocfs2_locking_protocol lproto = {
+ .lp_max_version = {
+ .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR,
+ .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR,
+ },
+ .lp_lock_ast = ocfs2_locking_ast,
+ .lp_blocking_ast = ocfs2_blocking_ast,
+ .lp_unlock_ast = ocfs2_unlock_ast,
+};
+
+void ocfs2_set_locking_protocol(void)
+{
+ ocfs2_stack_glue_set_max_proto_version(&lproto.lp_max_version);
+}
+
+static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres,
+ int convert)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ lockres_clear_flags(lockres, OCFS2_LOCK_BUSY);
+ lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
+ if (convert)
+ lockres->l_action = OCFS2_AST_INVALID;
+ else
+ lockres->l_unlock_action = OCFS2_UNLOCK_INVALID;
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ wake_up(&lockres->l_event);
+}
+
+/* Note: If we detect another process working on the lock (i.e.,
+ * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller
+ * to do the right thing in that case.
+ */
+static int ocfs2_lock_create(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ int level,
+ u32 dlm_flags)
+{
+ int ret = 0;
+ unsigned long flags;
+ unsigned int gen;
+
+ mlog(0, "lock %s, level = %d, flags = %u\n", lockres->l_name, level,
+ dlm_flags);
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) ||
+ (lockres->l_flags & OCFS2_LOCK_BUSY)) {
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ goto bail;
+ }
+
+ lockres->l_action = OCFS2_AST_ATTACH;
+ lockres->l_requested = level;
+ lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+ gen = lockres_set_pending(lockres);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ ret = ocfs2_dlm_lock(osb->cconn,
+ level,
+ &lockres->l_lksb,
+ dlm_flags,
+ lockres->l_name,
+ OCFS2_LOCK_ID_MAX_LEN - 1);
+ lockres_clear_pending(lockres, gen, osb);
+ if (ret) {
+ ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
+ ocfs2_recover_from_dlm_error(lockres, 1);
+ }
+
+ mlog(0, "lock %s, return from ocfs2_dlm_lock\n", lockres->l_name);
+
+bail:
+ return ret;
+}
+
+static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres,
+ int flag)
+{
+ unsigned long flags;
+ int ret;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ ret = lockres->l_flags & flag;
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ return ret;
+}
+
+static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres)
+
+{
+ wait_event(lockres->l_event,
+ !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY));
+}
+
+static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres)
+
+{
+ wait_event(lockres->l_event,
+ !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING));
+}
+
+/* predict what lock level we'll be dropping down to on behalf
+ * of another node, and return true if the currently wanted
+ * level will be compatible with it. */
+static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres,
+ int wanted)
+{
+ BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED));
+
+ return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking);
+}
+
+static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw)
+{
+ INIT_LIST_HEAD(&mw->mw_item);
+ init_completion(&mw->mw_complete);
+ ocfs2_init_start_time(mw);
+}
+
+static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw)
+{
+ wait_for_completion(&mw->mw_complete);
+ /* Re-arm the completion in case we want to wait on it again */
+ reinit_completion(&mw->mw_complete);
+ return mw->mw_status;
+}
+
+static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres,
+ struct ocfs2_mask_waiter *mw,
+ unsigned long mask,
+ unsigned long goal)
+{
+ BUG_ON(!list_empty(&mw->mw_item));
+
+ assert_spin_locked(&lockres->l_lock);
+
+ list_add_tail(&mw->mw_item, &lockres->l_mask_waiters);
+ mw->mw_mask = mask;
+ mw->mw_goal = goal;
+}
+
+/* returns 0 if the mw that was removed was already satisfied, -EBUSY
+ * if the mask still hadn't reached its goal */
+static int __lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
+ struct ocfs2_mask_waiter *mw)
+{
+ int ret = 0;
+
+ assert_spin_locked(&lockres->l_lock);
+ if (!list_empty(&mw->mw_item)) {
+ if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal)
+ ret = -EBUSY;
+
+ list_del_init(&mw->mw_item);
+ init_completion(&mw->mw_complete);
+ }
+
+ return ret;
+}
+
+static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres,
+ struct ocfs2_mask_waiter *mw)
+{
+ unsigned long flags;
+ int ret = 0;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ ret = __lockres_remove_mask_waiter(lockres, mw);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ return ret;
+
+}
+
+static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw,
+ struct ocfs2_lock_res *lockres)
+{
+ int ret;
+
+ ret = wait_for_completion_interruptible(&mw->mw_complete);
+ if (ret)
+ lockres_remove_mask_waiter(lockres, mw);
+ else
+ ret = mw->mw_status;
+ /* Re-arm the completion in case we want to wait on it again */
+ reinit_completion(&mw->mw_complete);
+ return ret;
+}
+
+static int __ocfs2_cluster_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ int level,
+ u32 lkm_flags,
+ int arg_flags,
+ int l_subclass,
+ unsigned long caller_ip)
+{
+ struct ocfs2_mask_waiter mw;
+ int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR);
+ int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */
+ unsigned long flags;
+ unsigned int gen;
+ int noqueue_attempted = 0;
+ int dlm_locked = 0;
+
+ if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) {
+ mlog_errno(-EINVAL);
+ return -EINVAL;
+ }
+
+ ocfs2_init_mask_waiter(&mw);
+
+ if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
+ lkm_flags |= DLM_LKF_VALBLK;
+
+again:
+ wait = 0;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+
+ if (catch_signals && signal_pending(current)) {
+ ret = -ERESTARTSYS;
+ goto unlock;
+ }
+
+ mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING,
+ "Cluster lock called on freeing lockres %s! flags "
+ "0x%lx\n", lockres->l_name, lockres->l_flags);
+
+ /* We only compare against the currently granted level
+ * here. If the lock is blocked waiting on a downconvert,
+ * we'll get caught below. */
+ if (lockres->l_flags & OCFS2_LOCK_BUSY &&
+ level > lockres->l_level) {
+ /* is someone sitting in dlm_lock? If so, wait on
+ * them. */
+ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+ wait = 1;
+ goto unlock;
+ }
+
+ if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) {
+ /*
+ * We've upconverted. If the lock now has a level we can
+ * work with, we take it. If, however, the lock is not at the
+ * required level, we go thru the full cycle. One way this could
+ * happen is if a process requesting an upconvert to PR is
+ * closely followed by another requesting upconvert to an EX.
+ * If the process requesting EX lands here, we want it to
+ * continue attempting to upconvert and let the process
+ * requesting PR take the lock.
+ * If multiple processes request upconvert to PR, the first one
+ * here will take the lock. The others will have to go thru the
+ * OCFS2_LOCK_BLOCKED check to ensure that there is no pending
+ * downconvert request.
+ */
+ if (level <= lockres->l_level)
+ goto update_holders;
+ }
+
+ if (lockres->l_flags & OCFS2_LOCK_BLOCKED &&
+ !ocfs2_may_continue_on_blocked_lock(lockres, level)) {
+ /* is the lock is currently blocked on behalf of
+ * another node */
+ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0);
+ wait = 1;
+ goto unlock;
+ }
+
+ if (level > lockres->l_level) {
+ if (noqueue_attempted > 0) {
+ ret = -EAGAIN;
+ goto unlock;
+ }
+ if (lkm_flags & DLM_LKF_NOQUEUE)
+ noqueue_attempted = 1;
+
+ if (lockres->l_action != OCFS2_AST_INVALID)
+ mlog(ML_ERROR, "lockres %s has action %u pending\n",
+ lockres->l_name, lockres->l_action);
+
+ if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
+ lockres->l_action = OCFS2_AST_ATTACH;
+ lkm_flags &= ~DLM_LKF_CONVERT;
+ } else {
+ lockres->l_action = OCFS2_AST_CONVERT;
+ lkm_flags |= DLM_LKF_CONVERT;
+ }
+
+ lockres->l_requested = level;
+ lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+ gen = lockres_set_pending(lockres);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ BUG_ON(level == DLM_LOCK_IV);
+ BUG_ON(level == DLM_LOCK_NL);
+
+ mlog(ML_BASTS, "lockres %s, convert from %d to %d\n",
+ lockres->l_name, lockres->l_level, level);
+
+ /* call dlm_lock to upgrade lock now */
+ ret = ocfs2_dlm_lock(osb->cconn,
+ level,
+ &lockres->l_lksb,
+ lkm_flags,
+ lockres->l_name,
+ OCFS2_LOCK_ID_MAX_LEN - 1);
+ lockres_clear_pending(lockres, gen, osb);
+ if (ret) {
+ if (!(lkm_flags & DLM_LKF_NOQUEUE) ||
+ (ret != -EAGAIN)) {
+ ocfs2_log_dlm_error("ocfs2_dlm_lock",
+ ret, lockres);
+ }
+ ocfs2_recover_from_dlm_error(lockres, 1);
+ goto out;
+ }
+ dlm_locked = 1;
+
+ mlog(0, "lock %s, successful return from ocfs2_dlm_lock\n",
+ lockres->l_name);
+
+ /* At this point we've gone inside the dlm and need to
+ * complete our work regardless. */
+ catch_signals = 0;
+
+ /* wait for busy to clear and carry on */
+ goto again;
+ }
+
+update_holders:
+ /* Ok, if we get here then we're good to go. */
+ ocfs2_inc_holders(lockres, level);
+
+ ret = 0;
+unlock:
+ lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING);
+
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+out:
+ /*
+ * This is helping work around a lock inversion between the page lock
+ * and dlm locks. One path holds the page lock while calling aops
+ * which block acquiring dlm locks. The voting thread holds dlm
+ * locks while acquiring page locks while down converting data locks.
+ * This block is helping an aop path notice the inversion and back
+ * off to unlock its page lock before trying the dlm lock again.
+ */
+ if (wait && arg_flags & OCFS2_LOCK_NONBLOCK &&
+ mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) {
+ wait = 0;
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ if (__lockres_remove_mask_waiter(lockres, &mw)) {
+ if (dlm_locked)
+ lockres_or_flags(lockres,
+ OCFS2_LOCK_NONBLOCK_FINISHED);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ ret = -EAGAIN;
+ } else {
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ goto again;
+ }
+ }
+ if (wait) {
+ ret = ocfs2_wait_for_mask(&mw);
+ if (ret == 0)
+ goto again;
+ mlog_errno(ret);
+ }
+ ocfs2_update_lock_stats(lockres, level, &mw, ret);
+
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ if (!ret && lockres->l_lockdep_map.key != NULL) {
+ if (level == DLM_LOCK_PR)
+ rwsem_acquire_read(&lockres->l_lockdep_map, l_subclass,
+ !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
+ caller_ip);
+ else
+ rwsem_acquire(&lockres->l_lockdep_map, l_subclass,
+ !!(arg_flags & OCFS2_META_LOCK_NOQUEUE),
+ caller_ip);
+ }
+#endif
+ return ret;
+}
+
+static inline int ocfs2_cluster_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ int level,
+ u32 lkm_flags,
+ int arg_flags)
+{
+ return __ocfs2_cluster_lock(osb, lockres, level, lkm_flags, arg_flags,
+ 0, _RET_IP_);
+}
+
+
+static void __ocfs2_cluster_unlock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ int level,
+ unsigned long caller_ip)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ ocfs2_dec_holders(lockres, level);
+ ocfs2_downconvert_on_unlock(osb, lockres);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+#ifdef CONFIG_DEBUG_LOCK_ALLOC
+ if (lockres->l_lockdep_map.key != NULL)
+ rwsem_release(&lockres->l_lockdep_map, 1, caller_ip);
+#endif
+}
+
+static int ocfs2_create_new_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ int ex,
+ int local)
+{
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ unsigned long flags;
+ u32 lkm_flags = local ? DLM_LKF_LOCAL : 0;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED);
+ lockres_or_flags(lockres, OCFS2_LOCK_LOCAL);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ return ocfs2_lock_create(osb, lockres, level, lkm_flags);
+}
+
+/* Grants us an EX lock on the data and metadata resources, skipping
+ * the normal cluster directory lookup. Use this ONLY on newly created
+ * inodes which other nodes can't possibly see, and which haven't been
+ * hashed in the inode hash yet. This can give us a good performance
+ * increase as it'll skip the network broadcast normally associated
+ * with creating a new lock resource. */
+int ocfs2_create_new_inode_locks(struct inode *inode)
+{
+ int ret;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ BUG_ON(!inode);
+ BUG_ON(!ocfs2_inode_is_new(inode));
+
+ mlog(0, "Inode %llu\n", (unsigned long long)OCFS2_I(inode)->ip_blkno);
+
+ /* NOTE: That we don't increment any of the holder counts, nor
+ * do we add anything to a journal handle. Since this is
+ * supposed to be a new inode which the cluster doesn't know
+ * about yet, there is no need to. As far as the LVB handling
+ * is concerned, this is basically like acquiring an EX lock
+ * on a resource which has an invalid one -- we'll set it
+ * valid when we release the EX. */
+
+ ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_rw_lockres, 1, 1);
+ if (ret) {
+ mlog_errno(ret);
+ goto bail;
+ }
+
+ /*
+ * We don't want to use DLM_LKF_LOCAL on a meta data lock as they
+ * don't use a generation in their lock names.
+ */
+ ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_inode_lockres, 1, 0);
+ if (ret) {
+ mlog_errno(ret);
+ goto bail;
+ }
+
+ ret = ocfs2_create_new_lock(osb, &OCFS2_I(inode)->ip_open_lockres, 0, 0);
+ if (ret) {
+ mlog_errno(ret);
+ goto bail;
+ }
+
+bail:
+ return ret;
+}
+
+int ocfs2_rw_lock(struct inode *inode, int write)
+{
+ int status, level;
+ struct ocfs2_lock_res *lockres;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ BUG_ON(!inode);
+
+ mlog(0, "inode %llu take %s RW lock\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno,
+ write ? "EXMODE" : "PRMODE");
+
+ if (ocfs2_mount_local(osb))
+ return 0;
+
+ lockres = &OCFS2_I(inode)->ip_rw_lockres;
+
+ level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
+
+ status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres, level, 0,
+ 0);
+ if (status < 0)
+ mlog_errno(status);
+
+ return status;
+}
+
+void ocfs2_rw_unlock(struct inode *inode, int write)
+{
+ int level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
+ struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_rw_lockres;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ mlog(0, "inode %llu drop %s RW lock\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno,
+ write ? "EXMODE" : "PRMODE");
+
+ if (!ocfs2_mount_local(osb))
+ ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
+}
+
+/*
+ * ocfs2_open_lock always get PR mode lock.
+ */
+int ocfs2_open_lock(struct inode *inode)
+{
+ int status = 0;
+ struct ocfs2_lock_res *lockres;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ BUG_ON(!inode);
+
+ mlog(0, "inode %llu take PRMODE open lock\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno);
+
+ if (ocfs2_is_hard_readonly(osb) || ocfs2_mount_local(osb))
+ goto out;
+
+ lockres = &OCFS2_I(inode)->ip_open_lockres;
+
+ status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
+ DLM_LOCK_PR, 0, 0);
+ if (status < 0)
+ mlog_errno(status);
+
+out:
+ return status;
+}
+
+int ocfs2_try_open_lock(struct inode *inode, int write)
+{
+ int status = 0, level;
+ struct ocfs2_lock_res *lockres;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ BUG_ON(!inode);
+
+ mlog(0, "inode %llu try to take %s open lock\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno,
+ write ? "EXMODE" : "PRMODE");
+
+ if (ocfs2_is_hard_readonly(osb)) {
+ if (write)
+ status = -EROFS;
+ goto out;
+ }
+
+ if (ocfs2_mount_local(osb))
+ goto out;
+
+ lockres = &OCFS2_I(inode)->ip_open_lockres;
+
+ level = write ? DLM_LOCK_EX : DLM_LOCK_PR;
+
+ /*
+ * The file system may already holding a PRMODE/EXMODE open lock.
+ * Since we pass DLM_LKF_NOQUEUE, the request won't block waiting on
+ * other nodes and the -EAGAIN will indicate to the caller that
+ * this inode is still in use.
+ */
+ status = ocfs2_cluster_lock(OCFS2_SB(inode->i_sb), lockres,
+ level, DLM_LKF_NOQUEUE, 0);
+
+out:
+ return status;
+}
+
+/*
+ * ocfs2_open_unlock unlock PR and EX mode open locks.
+ */
+void ocfs2_open_unlock(struct inode *inode)
+{
+ struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_open_lockres;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ mlog(0, "inode %llu drop open lock\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno);
+
+ if (ocfs2_mount_local(osb))
+ goto out;
+
+ if(lockres->l_ro_holders)
+ ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
+ DLM_LOCK_PR);
+ if(lockres->l_ex_holders)
+ ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres,
+ DLM_LOCK_EX);
+
+out:
+ return;
+}
+
+static int ocfs2_flock_handle_signal(struct ocfs2_lock_res *lockres,
+ int level)
+{
+ int ret;
+ struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres);
+ unsigned long flags;
+ struct ocfs2_mask_waiter mw;
+
+ ocfs2_init_mask_waiter(&mw);
+
+retry_cancel:
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ if (lockres->l_flags & OCFS2_LOCK_BUSY) {
+ ret = ocfs2_prepare_cancel_convert(osb, lockres);
+ if (ret) {
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ ret = ocfs2_cancel_convert(osb, lockres);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+ goto retry_cancel;
+ }
+ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ ocfs2_wait_for_mask(&mw);
+ goto retry_cancel;
+ }
+
+ ret = -ERESTARTSYS;
+ /*
+ * We may still have gotten the lock, in which case there's no
+ * point to restarting the syscall.
+ */
+ if (lockres->l_level == level)
+ ret = 0;
+
+ mlog(0, "Cancel returning %d. flags: 0x%lx, level: %d, act: %d\n", ret,
+ lockres->l_flags, lockres->l_level, lockres->l_action);
+
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+out:
+ return ret;
+}
+
+/*
+ * ocfs2_file_lock() and ocfs2_file_unlock() map to a single pair of
+ * flock() calls. The locking approach this requires is sufficiently
+ * different from all other cluster lock types that we implement a
+ * separate path to the "low-level" dlm calls. In particular:
+ *
+ * - No optimization of lock levels is done - we take at exactly
+ * what's been requested.
+ *
+ * - No lock caching is employed. We immediately downconvert to
+ * no-lock at unlock time. This also means flock locks never go on
+ * the blocking list).
+ *
+ * - Since userspace can trivially deadlock itself with flock, we make
+ * sure to allow cancellation of a misbehaving applications flock()
+ * request.
+ *
+ * - Access to any flock lockres doesn't require concurrency, so we
+ * can simplify the code by requiring the caller to guarantee
+ * serialization of dlmglue flock calls.
+ */
+int ocfs2_file_lock(struct file *file, int ex, int trylock)
+{
+ int ret, level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ unsigned int lkm_flags = trylock ? DLM_LKF_NOQUEUE : 0;
+ unsigned long flags;
+ struct ocfs2_file_private *fp = file->private_data;
+ struct ocfs2_lock_res *lockres = &fp->fp_flock;
+ struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
+ struct ocfs2_mask_waiter mw;
+
+ ocfs2_init_mask_waiter(&mw);
+
+ if ((lockres->l_flags & OCFS2_LOCK_BUSY) ||
+ (lockres->l_level > DLM_LOCK_NL)) {
+ mlog(ML_ERROR,
+ "File lock \"%s\" has busy or locked state: flags: 0x%lx, "
+ "level: %u\n", lockres->l_name, lockres->l_flags,
+ lockres->l_level);
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
+ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ /*
+ * Get the lock at NLMODE to start - that way we
+ * can cancel the upconvert request if need be.
+ */
+ ret = ocfs2_lock_create(osb, lockres, DLM_LOCK_NL, 0);
+ if (ret < 0) {
+ mlog_errno(ret);
+ goto out;
+ }
+
+ ret = ocfs2_wait_for_mask(&mw);
+ if (ret) {
+ mlog_errno(ret);
+ goto out;
+ }
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ }
+
+ lockres->l_action = OCFS2_AST_CONVERT;
+ lkm_flags |= DLM_LKF_CONVERT;
+ lockres->l_requested = level;
+ lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+
+ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ ret = ocfs2_dlm_lock(osb->cconn, level, &lockres->l_lksb, lkm_flags,
+ lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1);
+ if (ret) {
+ if (!trylock || (ret != -EAGAIN)) {
+ ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
+ ret = -EINVAL;
+ }
+
+ ocfs2_recover_from_dlm_error(lockres, 1);
+ lockres_remove_mask_waiter(lockres, &mw);
+ goto out;
+ }
+
+ ret = ocfs2_wait_for_mask_interruptible(&mw, lockres);
+ if (ret == -ERESTARTSYS) {
+ /*
+ * Userspace can cause deadlock itself with
+ * flock(). Current behavior locally is to allow the
+ * deadlock, but abort the system call if a signal is
+ * received. We follow this example, otherwise a
+ * poorly written program could sit in kernel until
+ * reboot.
+ *
+ * Handling this is a bit more complicated for Ocfs2
+ * though. We can't exit this function with an
+ * outstanding lock request, so a cancel convert is
+ * required. We intentionally overwrite 'ret' - if the
+ * cancel fails and the lock was granted, it's easier
+ * to just bubble success back up to the user.
+ */
+ ret = ocfs2_flock_handle_signal(lockres, level);
+ } else if (!ret && (level > lockres->l_level)) {
+ /* Trylock failed asynchronously */
+ BUG_ON(!trylock);
+ ret = -EAGAIN;
+ }
+
+out:
+
+ mlog(0, "Lock: \"%s\" ex: %d, trylock: %d, returns: %d\n",
+ lockres->l_name, ex, trylock, ret);
+ return ret;
+}
+
+void ocfs2_file_unlock(struct file *file)
+{
+ int ret;
+ unsigned int gen;
+ unsigned long flags;
+ struct ocfs2_file_private *fp = file->private_data;
+ struct ocfs2_lock_res *lockres = &fp->fp_flock;
+ struct ocfs2_super *osb = OCFS2_SB(file->f_mapping->host->i_sb);
+ struct ocfs2_mask_waiter mw;
+
+ ocfs2_init_mask_waiter(&mw);
+
+ if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED))
+ return;
+
+ if (lockres->l_level == DLM_LOCK_NL)
+ return;
+
+ mlog(0, "Unlock: \"%s\" flags: 0x%lx, level: %d, act: %d\n",
+ lockres->l_name, lockres->l_flags, lockres->l_level,
+ lockres->l_action);
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ /*
+ * Fake a blocking ast for the downconvert code.
+ */
+ lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED);
+ lockres->l_blocking = DLM_LOCK_EX;
+
+ gen = ocfs2_prepare_downconvert(lockres, DLM_LOCK_NL);
+ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ ret = ocfs2_downconvert_lock(osb, lockres, DLM_LOCK_NL, 0, gen);
+ if (ret) {
+ mlog_errno(ret);
+ return;
+ }
+
+ ret = ocfs2_wait_for_mask(&mw);
+ if (ret)
+ mlog_errno(ret);
+}
+
+static void ocfs2_downconvert_on_unlock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres)
+{
+ int kick = 0;
+
+ /* If we know that another node is waiting on our lock, kick
+ * the downconvert thread * pre-emptively when we reach a release
+ * condition. */
+ if (lockres->l_flags & OCFS2_LOCK_BLOCKED) {
+ switch(lockres->l_blocking) {
+ case DLM_LOCK_EX:
+ if (!lockres->l_ex_holders && !lockres->l_ro_holders)
+ kick = 1;
+ break;
+ case DLM_LOCK_PR:
+ if (!lockres->l_ex_holders)
+ kick = 1;
+ break;
+ default:
+ BUG();
+ }
+ }
+
+ if (kick)
+ ocfs2_wake_downconvert_thread(osb);
+}
+
+#define OCFS2_SEC_BITS 34
+#define OCFS2_SEC_SHIFT (64 - 34)
+#define OCFS2_NSEC_MASK ((1ULL << OCFS2_SEC_SHIFT) - 1)
+
+/* LVB only has room for 64 bits of time here so we pack it for
+ * now. */
+static u64 ocfs2_pack_timespec(struct timespec *spec)
+{
+ u64 res;
+ u64 sec = spec->tv_sec;
+ u32 nsec = spec->tv_nsec;
+
+ res = (sec << OCFS2_SEC_SHIFT) | (nsec & OCFS2_NSEC_MASK);
+
+ return res;
+}
+
+/* Call this with the lockres locked. I am reasonably sure we don't
+ * need ip_lock in this function as anyone who would be changing those
+ * values is supposed to be blocked in ocfs2_inode_lock right now. */
+static void __ocfs2_stuff_meta_lvb(struct inode *inode)
+{
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
+ struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
+ struct ocfs2_meta_lvb *lvb;
+
+ lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+
+ /*
+ * Invalidate the LVB of a deleted inode - this way other
+ * nodes are forced to go to disk and discover the new inode
+ * status.
+ */
+ if (oi->ip_flags & OCFS2_INODE_DELETED) {
+ lvb->lvb_version = 0;
+ goto out;
+ }
+
+ lvb->lvb_version = OCFS2_LVB_VERSION;
+ lvb->lvb_isize = cpu_to_be64(i_size_read(inode));
+ lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters);
+ lvb->lvb_iuid = cpu_to_be32(i_uid_read(inode));
+ lvb->lvb_igid = cpu_to_be32(i_gid_read(inode));
+ lvb->lvb_imode = cpu_to_be16(inode->i_mode);
+ lvb->lvb_inlink = cpu_to_be16(inode->i_nlink);
+ lvb->lvb_iatime_packed =
+ cpu_to_be64(ocfs2_pack_timespec(&inode->i_atime));
+ lvb->lvb_ictime_packed =
+ cpu_to_be64(ocfs2_pack_timespec(&inode->i_ctime));
+ lvb->lvb_imtime_packed =
+ cpu_to_be64(ocfs2_pack_timespec(&inode->i_mtime));
+ lvb->lvb_iattr = cpu_to_be32(oi->ip_attr);
+ lvb->lvb_idynfeatures = cpu_to_be16(oi->ip_dyn_features);
+ lvb->lvb_igeneration = cpu_to_be32(inode->i_generation);
+
+out:
+ mlog_meta_lvb(0, lockres);
+}
+
+static void ocfs2_unpack_timespec(struct timespec *spec,
+ u64 packed_time)
+{
+ spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT;
+ spec->tv_nsec = packed_time & OCFS2_NSEC_MASK;
+}
+
+static void ocfs2_refresh_inode_from_lvb(struct inode *inode)
+{
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
+ struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
+ struct ocfs2_meta_lvb *lvb;
+
+ mlog_meta_lvb(0, lockres);
+
+ lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+
+ /* We're safe here without the lockres lock... */
+ spin_lock(&oi->ip_lock);
+ oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters);
+ i_size_write(inode, be64_to_cpu(lvb->lvb_isize));
+
+ oi->ip_attr = be32_to_cpu(lvb->lvb_iattr);
+ oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures);
+ ocfs2_set_inode_flags(inode);
+
+ /* fast-symlinks are a special case */
+ if (S_ISLNK(inode->i_mode) && !oi->ip_clusters)
+ inode->i_blocks = 0;
+ else
+ inode->i_blocks = ocfs2_inode_sector_count(inode);
+
+ i_uid_write(inode, be32_to_cpu(lvb->lvb_iuid));
+ i_gid_write(inode, be32_to_cpu(lvb->lvb_igid));
+ inode->i_mode = be16_to_cpu(lvb->lvb_imode);
+ set_nlink(inode, be16_to_cpu(lvb->lvb_inlink));
+ ocfs2_unpack_timespec(&inode->i_atime,
+ be64_to_cpu(lvb->lvb_iatime_packed));
+ ocfs2_unpack_timespec(&inode->i_mtime,
+ be64_to_cpu(lvb->lvb_imtime_packed));
+ ocfs2_unpack_timespec(&inode->i_ctime,
+ be64_to_cpu(lvb->lvb_ictime_packed));
+ spin_unlock(&oi->ip_lock);
+}
+
+static inline int ocfs2_meta_lvb_is_trustable(struct inode *inode,
+ struct ocfs2_lock_res *lockres)
+{
+ struct ocfs2_meta_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+
+ if (ocfs2_dlm_lvb_valid(&lockres->l_lksb)
+ && lvb->lvb_version == OCFS2_LVB_VERSION
+ && be32_to_cpu(lvb->lvb_igeneration) == inode->i_generation)
+ return 1;
+ return 0;
+}
+
+/* Determine whether a lock resource needs to be refreshed, and
+ * arbitrate who gets to refresh it.
+ *
+ * 0 means no refresh needed.
+ *
+ * > 0 means you need to refresh this and you MUST call
+ * ocfs2_complete_lock_res_refresh afterwards. */
+static int ocfs2_should_refresh_lock_res(struct ocfs2_lock_res *lockres)
+{
+ unsigned long flags;
+ int status = 0;
+
+refresh_check:
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ if (!(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) {
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ goto bail;
+ }
+
+ if (lockres->l_flags & OCFS2_LOCK_REFRESHING) {
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ ocfs2_wait_on_refreshing_lock(lockres);
+ goto refresh_check;
+ }
+
+ /* Ok, I'll be the one to refresh this lock. */
+ lockres_or_flags(lockres, OCFS2_LOCK_REFRESHING);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ status = 1;
+bail:
+ mlog(0, "status %d\n", status);
+ return status;
+}
+
+/* If status is non zero, I'll mark it as not being in refresh
+ * anymroe, but i won't clear the needs refresh flag. */
+static inline void ocfs2_complete_lock_res_refresh(struct ocfs2_lock_res *lockres,
+ int status)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ lockres_clear_flags(lockres, OCFS2_LOCK_REFRESHING);
+ if (!status)
+ lockres_clear_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ wake_up(&lockres->l_event);
+}
+
+/* may or may not return a bh if it went to disk. */
+static int ocfs2_inode_lock_update(struct inode *inode,
+ struct buffer_head **bh)
+{
+ int status = 0;
+ struct ocfs2_inode_info *oi = OCFS2_I(inode);
+ struct ocfs2_lock_res *lockres = &oi->ip_inode_lockres;
+ struct ocfs2_dinode *fe;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ if (ocfs2_mount_local(osb))
+ goto bail;
+
+ spin_lock(&oi->ip_lock);
+ if (oi->ip_flags & OCFS2_INODE_DELETED) {
+ mlog(0, "Orphaned inode %llu was deleted while we "
+ "were waiting on a lock. ip_flags = 0x%x\n",
+ (unsigned long long)oi->ip_blkno, oi->ip_flags);
+ spin_unlock(&oi->ip_lock);
+ status = -ENOENT;
+ goto bail;
+ }
+ spin_unlock(&oi->ip_lock);
+
+ if (!ocfs2_should_refresh_lock_res(lockres))
+ goto bail;
+
+ /* This will discard any caching information we might have had
+ * for the inode metadata. */
+ ocfs2_metadata_cache_purge(INODE_CACHE(inode));
+
+ ocfs2_extent_map_trunc(inode, 0);
+
+ if (ocfs2_meta_lvb_is_trustable(inode, lockres)) {
+ mlog(0, "Trusting LVB on inode %llu\n",
+ (unsigned long long)oi->ip_blkno);
+ ocfs2_refresh_inode_from_lvb(inode);
+ } else {
+ /* Boo, we have to go to disk. */
+ /* read bh, cast, ocfs2_refresh_inode */
+ status = ocfs2_read_inode_block(inode, bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail_refresh;
+ }
+ fe = (struct ocfs2_dinode *) (*bh)->b_data;
+
+ /* This is a good chance to make sure we're not
+ * locking an invalid object. ocfs2_read_inode_block()
+ * already checked that the inode block is sane.
+ *
+ * We bug on a stale inode here because we checked
+ * above whether it was wiped from disk. The wiping
+ * node provides a guarantee that we receive that
+ * message and can mark the inode before dropping any
+ * locks associated with it. */
+ mlog_bug_on_msg(inode->i_generation !=
+ le32_to_cpu(fe->i_generation),
+ "Invalid dinode %llu disk generation: %u "
+ "inode->i_generation: %u\n",
+ (unsigned long long)oi->ip_blkno,
+ le32_to_cpu(fe->i_generation),
+ inode->i_generation);
+ mlog_bug_on_msg(le64_to_cpu(fe->i_dtime) ||
+ !(fe->i_flags & cpu_to_le32(OCFS2_VALID_FL)),
+ "Stale dinode %llu dtime: %llu flags: 0x%x\n",
+ (unsigned long long)oi->ip_blkno,
+ (unsigned long long)le64_to_cpu(fe->i_dtime),
+ le32_to_cpu(fe->i_flags));
+
+ ocfs2_refresh_inode(inode, fe);
+ ocfs2_track_lock_refresh(lockres);
+ }
+
+ status = 0;
+bail_refresh:
+ ocfs2_complete_lock_res_refresh(lockres, status);
+bail:
+ return status;
+}
+
+static int ocfs2_assign_bh(struct inode *inode,
+ struct buffer_head **ret_bh,
+ struct buffer_head *passed_bh)
+{
+ int status;
+
+ if (passed_bh) {
+ /* Ok, the update went to disk for us, use the
+ * returned bh. */
+ *ret_bh = passed_bh;
+ get_bh(*ret_bh);
+
+ return 0;
+ }
+
+ status = ocfs2_read_inode_block(inode, ret_bh);
+ if (status < 0)
+ mlog_errno(status);
+
+ return status;
+}
+
+/*
+ * returns < 0 error if the callback will never be called, otherwise
+ * the result of the lock will be communicated via the callback.
+ */
+int ocfs2_inode_lock_full_nested(struct inode *inode,
+ struct buffer_head **ret_bh,
+ int ex,
+ int arg_flags,
+ int subclass)
+{
+ int status, level, acquired;
+ u32 dlm_flags;
+ struct ocfs2_lock_res *lockres = NULL;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+ struct buffer_head *local_bh = NULL;
+
+ BUG_ON(!inode);
+
+ mlog(0, "inode %llu, take %s META lock\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno,
+ ex ? "EXMODE" : "PRMODE");
+
+ status = 0;
+ acquired = 0;
+ /* We'll allow faking a readonly metadata lock for
+ * rodevices. */
+ if (ocfs2_is_hard_readonly(osb)) {
+ if (ex)
+ status = -EROFS;
+ goto getbh;
+ }
+
+ if (ocfs2_mount_local(osb))
+ goto local;
+
+ if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
+ ocfs2_wait_for_recovery(osb);
+
+ lockres = &OCFS2_I(inode)->ip_inode_lockres;
+ level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ dlm_flags = 0;
+ if (arg_flags & OCFS2_META_LOCK_NOQUEUE)
+ dlm_flags |= DLM_LKF_NOQUEUE;
+
+ status = __ocfs2_cluster_lock(osb, lockres, level, dlm_flags,
+ arg_flags, subclass, _RET_IP_);
+ if (status < 0) {
+ if (status != -EAGAIN)
+ mlog_errno(status);
+ goto bail;
+ }
+
+ /* Notify the error cleanup path to drop the cluster lock. */
+ acquired = 1;
+
+ /* We wait twice because a node may have died while we were in
+ * the lower dlm layers. The second time though, we've
+ * committed to owning this lock so we don't allow signals to
+ * abort the operation. */
+ if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
+ ocfs2_wait_for_recovery(osb);
+
+local:
+ /*
+ * We only see this flag if we're being called from
+ * ocfs2_read_locked_inode(). It means we're locking an inode
+ * which hasn't been populated yet, so clear the refresh flag
+ * and let the caller handle it.
+ */
+ if (inode->i_state & I_NEW) {
+ status = 0;
+ if (lockres)
+ ocfs2_complete_lock_res_refresh(lockres, 0);
+ goto bail;
+ }
+
+ /* This is fun. The caller may want a bh back, or it may
+ * not. ocfs2_inode_lock_update definitely wants one in, but
+ * may or may not read one, depending on what's in the
+ * LVB. The result of all of this is that we've *only* gone to
+ * disk if we have to, so the complexity is worthwhile. */
+ status = ocfs2_inode_lock_update(inode, &local_bh);
+ if (status < 0) {
+ if (status != -ENOENT)
+ mlog_errno(status);
+ goto bail;
+ }
+getbh:
+ if (ret_bh) {
+ status = ocfs2_assign_bh(inode, ret_bh, local_bh);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ }
+
+bail:
+ if (status < 0) {
+ if (ret_bh && (*ret_bh)) {
+ brelse(*ret_bh);
+ *ret_bh = NULL;
+ }
+ if (acquired)
+ ocfs2_inode_unlock(inode, ex);
+ }
+
+ if (local_bh)
+ brelse(local_bh);
+
+ return status;
+}
+
+/*
+ * This is working around a lock inversion between tasks acquiring DLM
+ * locks while holding a page lock and the downconvert thread which
+ * blocks dlm lock acquiry while acquiring page locks.
+ *
+ * ** These _with_page variantes are only intended to be called from aop
+ * methods that hold page locks and return a very specific *positive* error
+ * code that aop methods pass up to the VFS -- test for errors with != 0. **
+ *
+ * The DLM is called such that it returns -EAGAIN if it would have
+ * blocked waiting for the downconvert thread. In that case we unlock
+ * our page so the downconvert thread can make progress. Once we've
+ * done this we have to return AOP_TRUNCATED_PAGE so the aop method
+ * that called us can bubble that back up into the VFS who will then
+ * immediately retry the aop call.
+ *
+ * We do a blocking lock and immediate unlock before returning, though, so that
+ * the lock has a great chance of being cached on this node by the time the VFS
+ * calls back to retry the aop. This has a potential to livelock as nodes
+ * ping locks back and forth, but that's a risk we're willing to take to avoid
+ * the lock inversion simply.
+ */
+int ocfs2_inode_lock_with_page(struct inode *inode,
+ struct buffer_head **ret_bh,
+ int ex,
+ struct page *page)
+{
+ int ret;
+
+ ret = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_LOCK_NONBLOCK);
+ if (ret == -EAGAIN) {
+ unlock_page(page);
+ if (ocfs2_inode_lock(inode, ret_bh, ex) == 0)
+ ocfs2_inode_unlock(inode, ex);
+ ret = AOP_TRUNCATED_PAGE;
+ }
+
+ return ret;
+}
+
+int ocfs2_inode_lock_atime(struct inode *inode,
+ struct vfsmount *vfsmnt,
+ int *level)
+{
+ int ret;
+
+ ret = ocfs2_inode_lock(inode, NULL, 0);
+ if (ret < 0) {
+ mlog_errno(ret);
+ return ret;
+ }
+
+ /*
+ * If we should update atime, we will get EX lock,
+ * otherwise we just get PR lock.
+ */
+ if (ocfs2_should_update_atime(inode, vfsmnt)) {
+ struct buffer_head *bh = NULL;
+
+ ocfs2_inode_unlock(inode, 0);
+ ret = ocfs2_inode_lock(inode, &bh, 1);
+ if (ret < 0) {
+ mlog_errno(ret);
+ return ret;
+ }
+ *level = 1;
+ if (ocfs2_should_update_atime(inode, vfsmnt))
+ ocfs2_update_inode_atime(inode, bh);
+ if (bh)
+ brelse(bh);
+ } else
+ *level = 0;
+
+ return ret;
+}
+
+void ocfs2_inode_unlock(struct inode *inode,
+ int ex)
+{
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ struct ocfs2_lock_res *lockres = &OCFS2_I(inode)->ip_inode_lockres;
+ struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
+
+ mlog(0, "inode %llu drop %s META lock\n",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno,
+ ex ? "EXMODE" : "PRMODE");
+
+ if (!ocfs2_is_hard_readonly(OCFS2_SB(inode->i_sb)) &&
+ !ocfs2_mount_local(osb))
+ ocfs2_cluster_unlock(OCFS2_SB(inode->i_sb), lockres, level);
+}
+
+int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno)
+{
+ struct ocfs2_lock_res *lockres;
+ struct ocfs2_orphan_scan_lvb *lvb;
+ int status = 0;
+
+ if (ocfs2_is_hard_readonly(osb))
+ return -EROFS;
+
+ if (ocfs2_mount_local(osb))
+ return 0;
+
+ lockres = &osb->osb_orphan_scan.os_lockres;
+ status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
+ if (status < 0)
+ return status;
+
+ lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+ if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
+ lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION)
+ *seqno = be32_to_cpu(lvb->lvb_os_seqno);
+ else
+ *seqno = osb->osb_orphan_scan.os_seqno + 1;
+
+ return status;
+}
+
+void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno)
+{
+ struct ocfs2_lock_res *lockres;
+ struct ocfs2_orphan_scan_lvb *lvb;
+
+ if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) {
+ lockres = &osb->osb_orphan_scan.os_lockres;
+ lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+ lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION;
+ lvb->lvb_os_seqno = cpu_to_be32(seqno);
+ ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
+ }
+}
+
+int ocfs2_super_lock(struct ocfs2_super *osb,
+ int ex)
+{
+ int status = 0;
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
+
+ if (ocfs2_is_hard_readonly(osb))
+ return -EROFS;
+
+ if (ocfs2_mount_local(osb))
+ goto bail;
+
+ status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ /* The super block lock path is really in the best position to
+ * know when resources covered by the lock need to be
+ * refreshed, so we do it here. Of course, making sense of
+ * everything is up to the caller :) */
+ status = ocfs2_should_refresh_lock_res(lockres);
+ if (status) {
+ status = ocfs2_refresh_slot_info(osb);
+
+ ocfs2_complete_lock_res_refresh(lockres, status);
+
+ if (status < 0) {
+ ocfs2_cluster_unlock(osb, lockres, level);
+ mlog_errno(status);
+ }
+ ocfs2_track_lock_refresh(lockres);
+ }
+bail:
+ return status;
+}
+
+void ocfs2_super_unlock(struct ocfs2_super *osb,
+ int ex)
+{
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ struct ocfs2_lock_res *lockres = &osb->osb_super_lockres;
+
+ if (!ocfs2_mount_local(osb))
+ ocfs2_cluster_unlock(osb, lockres, level);
+}
+
+int ocfs2_rename_lock(struct ocfs2_super *osb)
+{
+ int status;
+ struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
+
+ if (ocfs2_is_hard_readonly(osb))
+ return -EROFS;
+
+ if (ocfs2_mount_local(osb))
+ return 0;
+
+ status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0);
+ if (status < 0)
+ mlog_errno(status);
+
+ return status;
+}
+
+void ocfs2_rename_unlock(struct ocfs2_super *osb)
+{
+ struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres;
+
+ if (!ocfs2_mount_local(osb))
+ ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX);
+}
+
+int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex)
+{
+ int status;
+ struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
+
+ if (ocfs2_is_hard_readonly(osb))
+ return -EROFS;
+
+ if (ocfs2_mount_local(osb))
+ return 0;
+
+ status = ocfs2_cluster_lock(osb, lockres, ex ? LKM_EXMODE : LKM_PRMODE,
+ 0, 0);
+ if (status < 0)
+ mlog(ML_ERROR, "lock on nfs sync lock failed %d\n", status);
+
+ return status;
+}
+
+void ocfs2_nfs_sync_unlock(struct ocfs2_super *osb, int ex)
+{
+ struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres;
+
+ if (!ocfs2_mount_local(osb))
+ ocfs2_cluster_unlock(osb, lockres,
+ ex ? LKM_EXMODE : LKM_PRMODE);
+}
+
+int ocfs2_dentry_lock(struct dentry *dentry, int ex)
+{
+ int ret;
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
+ struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
+
+ BUG_ON(!dl);
+
+ if (ocfs2_is_hard_readonly(osb)) {
+ if (ex)
+ return -EROFS;
+ return 0;
+ }
+
+ if (ocfs2_mount_local(osb))
+ return 0;
+
+ ret = ocfs2_cluster_lock(osb, &dl->dl_lockres, level, 0, 0);
+ if (ret < 0)
+ mlog_errno(ret);
+
+ return ret;
+}
+
+void ocfs2_dentry_unlock(struct dentry *dentry, int ex)
+{
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ struct ocfs2_dentry_lock *dl = dentry->d_fsdata;
+ struct ocfs2_super *osb = OCFS2_SB(dentry->d_sb);
+
+ if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
+ ocfs2_cluster_unlock(osb, &dl->dl_lockres, level);
+}
+
+/* Reference counting of the dlm debug structure. We want this because
+ * open references on the debug inodes can live on after a mount, so
+ * we can't rely on the ocfs2_super to always exist. */
+static void ocfs2_dlm_debug_free(struct kref *kref)
+{
+ struct ocfs2_dlm_debug *dlm_debug;
+
+ dlm_debug = container_of(kref, struct ocfs2_dlm_debug, d_refcnt);
+
+ kfree(dlm_debug);
+}
+
+void ocfs2_put_dlm_debug(struct ocfs2_dlm_debug *dlm_debug)
+{
+ if (dlm_debug)
+ kref_put(&dlm_debug->d_refcnt, ocfs2_dlm_debug_free);
+}
+
+static void ocfs2_get_dlm_debug(struct ocfs2_dlm_debug *debug)
+{
+ kref_get(&debug->d_refcnt);
+}
+
+struct ocfs2_dlm_debug *ocfs2_new_dlm_debug(void)
+{
+ struct ocfs2_dlm_debug *dlm_debug;
+
+ dlm_debug = kmalloc(sizeof(struct ocfs2_dlm_debug), GFP_KERNEL);
+ if (!dlm_debug) {
+ mlog_errno(-ENOMEM);
+ goto out;
+ }
+
+ kref_init(&dlm_debug->d_refcnt);
+ INIT_LIST_HEAD(&dlm_debug->d_lockres_tracking);
+ dlm_debug->d_locking_state = NULL;
+out:
+ return dlm_debug;
+}
+
+/* Access to this is arbitrated for us via seq_file->sem. */
+struct ocfs2_dlm_seq_priv {
+ struct ocfs2_dlm_debug *p_dlm_debug;
+ struct ocfs2_lock_res p_iter_res;
+ struct ocfs2_lock_res p_tmp_res;
+};
+
+static struct ocfs2_lock_res *ocfs2_dlm_next_res(struct ocfs2_lock_res *start,
+ struct ocfs2_dlm_seq_priv *priv)
+{
+ struct ocfs2_lock_res *iter, *ret = NULL;
+ struct ocfs2_dlm_debug *dlm_debug = priv->p_dlm_debug;
+
+ assert_spin_locked(&ocfs2_dlm_tracking_lock);
+
+ list_for_each_entry(iter, &start->l_debug_list, l_debug_list) {
+ /* discover the head of the list */
+ if (&iter->l_debug_list == &dlm_debug->d_lockres_tracking) {
+ mlog(0, "End of list found, %p\n", ret);
+ break;
+ }
+
+ /* We track our "dummy" iteration lockres' by a NULL
+ * l_ops field. */
+ if (iter->l_ops != NULL) {
+ ret = iter;
+ break;
+ }
+ }
+
+ return ret;
+}
+
+static void *ocfs2_dlm_seq_start(struct seq_file *m, loff_t *pos)
+{
+ struct ocfs2_dlm_seq_priv *priv = m->private;
+ struct ocfs2_lock_res *iter;
+
+ spin_lock(&ocfs2_dlm_tracking_lock);
+ iter = ocfs2_dlm_next_res(&priv->p_iter_res, priv);
+ if (iter) {
+ /* Since lockres' have the lifetime of their container
+ * (which can be inodes, ocfs2_supers, etc) we want to
+ * copy this out to a temporary lockres while still
+ * under the spinlock. Obviously after this we can't
+ * trust any pointers on the copy returned, but that's
+ * ok as the information we want isn't typically held
+ * in them. */
+ priv->p_tmp_res = *iter;
+ iter = &priv->p_tmp_res;
+ }
+ spin_unlock(&ocfs2_dlm_tracking_lock);
+
+ return iter;
+}
+
+static void ocfs2_dlm_seq_stop(struct seq_file *m, void *v)
+{
+}
+
+static void *ocfs2_dlm_seq_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct ocfs2_dlm_seq_priv *priv = m->private;
+ struct ocfs2_lock_res *iter = v;
+ struct ocfs2_lock_res *dummy = &priv->p_iter_res;
+
+ spin_lock(&ocfs2_dlm_tracking_lock);
+ iter = ocfs2_dlm_next_res(iter, priv);
+ list_del_init(&dummy->l_debug_list);
+ if (iter) {
+ list_add(&dummy->l_debug_list, &iter->l_debug_list);
+ priv->p_tmp_res = *iter;
+ iter = &priv->p_tmp_res;
+ }
+ spin_unlock(&ocfs2_dlm_tracking_lock);
+
+ return iter;
+}
+
+/*
+ * Version is used by debugfs.ocfs2 to determine the format being used
+ *
+ * New in version 2
+ * - Lock stats printed
+ * New in version 3
+ * - Max time in lock stats is in usecs (instead of nsecs)
+ */
+#define OCFS2_DLM_DEBUG_STR_VERSION 3
+static int ocfs2_dlm_seq_show(struct seq_file *m, void *v)
+{
+ int i;
+ char *lvb;
+ struct ocfs2_lock_res *lockres = v;
+
+ if (!lockres)
+ return -EINVAL;
+
+ seq_printf(m, "0x%x\t", OCFS2_DLM_DEBUG_STR_VERSION);
+
+ if (lockres->l_type == OCFS2_LOCK_TYPE_DENTRY)
+ seq_printf(m, "%.*s%08x\t", OCFS2_DENTRY_LOCK_INO_START - 1,
+ lockres->l_name,
+ (unsigned int)ocfs2_get_dentry_lock_ino(lockres));
+ else
+ seq_printf(m, "%.*s\t", OCFS2_LOCK_ID_MAX_LEN, lockres->l_name);
+
+ seq_printf(m, "%d\t"
+ "0x%lx\t"
+ "0x%x\t"
+ "0x%x\t"
+ "%u\t"
+ "%u\t"
+ "%d\t"
+ "%d\t",
+ lockres->l_level,
+ lockres->l_flags,
+ lockres->l_action,
+ lockres->l_unlock_action,
+ lockres->l_ro_holders,
+ lockres->l_ex_holders,
+ lockres->l_requested,
+ lockres->l_blocking);
+
+ /* Dump the raw LVB */
+ lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+ for(i = 0; i < DLM_LVB_LEN; i++)
+ seq_printf(m, "0x%x\t", lvb[i]);
+
+#ifdef CONFIG_OCFS2_FS_STATS
+# define lock_num_prmode(_l) ((_l)->l_lock_prmode.ls_gets)
+# define lock_num_exmode(_l) ((_l)->l_lock_exmode.ls_gets)
+# define lock_num_prmode_failed(_l) ((_l)->l_lock_prmode.ls_fail)
+# define lock_num_exmode_failed(_l) ((_l)->l_lock_exmode.ls_fail)
+# define lock_total_prmode(_l) ((_l)->l_lock_prmode.ls_total)
+# define lock_total_exmode(_l) ((_l)->l_lock_exmode.ls_total)
+# define lock_max_prmode(_l) ((_l)->l_lock_prmode.ls_max)
+# define lock_max_exmode(_l) ((_l)->l_lock_exmode.ls_max)
+# define lock_refresh(_l) ((_l)->l_lock_refresh)
+#else
+# define lock_num_prmode(_l) (0)
+# define lock_num_exmode(_l) (0)
+# define lock_num_prmode_failed(_l) (0)
+# define lock_num_exmode_failed(_l) (0)
+# define lock_total_prmode(_l) (0ULL)
+# define lock_total_exmode(_l) (0ULL)
+# define lock_max_prmode(_l) (0)
+# define lock_max_exmode(_l) (0)
+# define lock_refresh(_l) (0)
+#endif
+ /* The following seq_print was added in version 2 of this output */
+ seq_printf(m, "%u\t"
+ "%u\t"
+ "%u\t"
+ "%u\t"
+ "%llu\t"
+ "%llu\t"
+ "%u\t"
+ "%u\t"
+ "%u\t",
+ lock_num_prmode(lockres),
+ lock_num_exmode(lockres),
+ lock_num_prmode_failed(lockres),
+ lock_num_exmode_failed(lockres),
+ lock_total_prmode(lockres),
+ lock_total_exmode(lockres),
+ lock_max_prmode(lockres),
+ lock_max_exmode(lockres),
+ lock_refresh(lockres));
+
+ /* End the line */
+ seq_printf(m, "\n");
+ return 0;
+}
+
+static const struct seq_operations ocfs2_dlm_seq_ops = {
+ .start = ocfs2_dlm_seq_start,
+ .stop = ocfs2_dlm_seq_stop,
+ .next = ocfs2_dlm_seq_next,
+ .show = ocfs2_dlm_seq_show,
+};
+
+static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file)
+{
+ struct seq_file *seq = file->private_data;
+ struct ocfs2_dlm_seq_priv *priv = seq->private;
+ struct ocfs2_lock_res *res = &priv->p_iter_res;
+
+ ocfs2_remove_lockres_tracking(res);
+ ocfs2_put_dlm_debug(priv->p_dlm_debug);
+ return seq_release_private(inode, file);
+}
+
+static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file)
+{
+ struct ocfs2_dlm_seq_priv *priv;
+ struct ocfs2_super *osb;
+
+ priv = __seq_open_private(file, &ocfs2_dlm_seq_ops, sizeof(*priv));
+ if (!priv) {
+ mlog_errno(-ENOMEM);
+ return -ENOMEM;
+ }
+
+ osb = inode->i_private;
+ ocfs2_get_dlm_debug(osb->osb_dlm_debug);
+ priv->p_dlm_debug = osb->osb_dlm_debug;
+ INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list);
+
+ ocfs2_add_lockres_tracking(&priv->p_iter_res,
+ priv->p_dlm_debug);
+
+ return 0;
+}
+
+static const struct file_operations ocfs2_dlm_debug_fops = {
+ .open = ocfs2_dlm_debug_open,
+ .release = ocfs2_dlm_debug_release,
+ .read = seq_read,
+ .llseek = seq_lseek,
+};
+
+static int ocfs2_dlm_init_debug(struct ocfs2_super *osb)
+{
+ int ret = 0;
+ struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
+
+ dlm_debug->d_locking_state = debugfs_create_file("locking_state",
+ S_IFREG|S_IRUSR,
+ osb->osb_debug_root,
+ osb,
+ &ocfs2_dlm_debug_fops);
+ if (!dlm_debug->d_locking_state) {
+ ret = -EINVAL;
+ mlog(ML_ERROR,
+ "Unable to create locking state debugfs file.\n");
+ goto out;
+ }
+
+ ocfs2_get_dlm_debug(dlm_debug);
+out:
+ return ret;
+}
+
+static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb)
+{
+ struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug;
+
+ if (dlm_debug) {
+ debugfs_remove(dlm_debug->d_locking_state);
+ ocfs2_put_dlm_debug(dlm_debug);
+ }
+}
+
+int ocfs2_dlm_init(struct ocfs2_super *osb)
+{
+ int status = 0;
+ struct ocfs2_cluster_connection *conn = NULL;
+
+ if (ocfs2_mount_local(osb)) {
+ osb->node_num = 0;
+ goto local;
+ }
+
+ status = ocfs2_dlm_init_debug(osb);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ /* launch downconvert thread */
+ osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc");
+ if (IS_ERR(osb->dc_task)) {
+ status = PTR_ERR(osb->dc_task);
+ osb->dc_task = NULL;
+ mlog_errno(status);
+ goto bail;
+ }
+
+ /* for now, uuid == domain */
+ status = ocfs2_cluster_connect(osb->osb_cluster_stack,
+ osb->osb_cluster_name,
+ strlen(osb->osb_cluster_name),
+ osb->uuid_str,
+ strlen(osb->uuid_str),
+ &lproto, ocfs2_do_node_down, osb,
+ &conn);
+ if (status) {
+ mlog_errno(status);
+ goto bail;
+ }
+
+ status = ocfs2_cluster_this_node(conn, &osb->node_num);
+ if (status < 0) {
+ mlog_errno(status);
+ mlog(ML_ERROR,
+ "could not find this host's node number\n");
+ ocfs2_cluster_disconnect(conn, 0);
+ goto bail;
+ }
+
+local:
+ ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb);
+ ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb);
+ ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb);
+ ocfs2_orphan_scan_lock_res_init(&osb->osb_orphan_scan.os_lockres, osb);
+
+ osb->cconn = conn;
+
+ status = 0;
+bail:
+ if (status < 0) {
+ ocfs2_dlm_shutdown_debug(osb);
+ if (osb->dc_task)
+ kthread_stop(osb->dc_task);
+ }
+
+ return status;
+}
+
+void ocfs2_dlm_shutdown(struct ocfs2_super *osb,
+ int hangup_pending)
+{
+ ocfs2_drop_osb_locks(osb);
+
+ /*
+ * Now that we have dropped all locks and ocfs2_dismount_volume()
+ * has disabled recovery, the DLM won't be talking to us. It's
+ * safe to tear things down before disconnecting the cluster.
+ */
+
+ if (osb->dc_task) {
+ kthread_stop(osb->dc_task);
+ osb->dc_task = NULL;
+ }
+
+ ocfs2_lock_res_free(&osb->osb_super_lockres);
+ ocfs2_lock_res_free(&osb->osb_rename_lockres);
+ ocfs2_lock_res_free(&osb->osb_nfs_sync_lockres);
+ ocfs2_lock_res_free(&osb->osb_orphan_scan.os_lockres);
+
+ ocfs2_cluster_disconnect(osb->cconn, hangup_pending);
+ osb->cconn = NULL;
+
+ ocfs2_dlm_shutdown_debug(osb);
+}
+
+static int ocfs2_drop_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres)
+{
+ int ret;
+ unsigned long flags;
+ u32 lkm_flags = 0;
+
+ /* We didn't get anywhere near actually using this lockres. */
+ if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED))
+ goto out;
+
+ if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB)
+ lkm_flags |= DLM_LKF_VALBLK;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+
+ mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING),
+ "lockres %s, flags 0x%lx\n",
+ lockres->l_name, lockres->l_flags);
+
+ while (lockres->l_flags & OCFS2_LOCK_BUSY) {
+ mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = "
+ "%u, unlock_action = %u\n",
+ lockres->l_name, lockres->l_flags, lockres->l_action,
+ lockres->l_unlock_action);
+
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ /* XXX: Today we just wait on any busy
+ * locks... Perhaps we need to cancel converts in the
+ * future? */
+ ocfs2_wait_on_busy_lock(lockres);
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ }
+
+ if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
+ if (lockres->l_flags & OCFS2_LOCK_ATTACHED &&
+ lockres->l_level == DLM_LOCK_EX &&
+ !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
+ lockres->l_ops->set_lvb(lockres);
+ }
+
+ if (lockres->l_flags & OCFS2_LOCK_BUSY)
+ mlog(ML_ERROR, "destroying busy lock: \"%s\"\n",
+ lockres->l_name);
+ if (lockres->l_flags & OCFS2_LOCK_BLOCKED)
+ mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name);
+
+ if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) {
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ goto out;
+ }
+
+ lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED);
+
+ /* make sure we never get here while waiting for an ast to
+ * fire. */
+ BUG_ON(lockres->l_action != OCFS2_AST_INVALID);
+
+ /* is this necessary? */
+ lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+ lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK;
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ mlog(0, "lock %s\n", lockres->l_name);
+
+ ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb, lkm_flags);
+ if (ret) {
+ ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
+ mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags);
+ ocfs2_dlm_dump_lksb(&lockres->l_lksb);
+ BUG();
+ }
+ mlog(0, "lock %s, successful return from ocfs2_dlm_unlock\n",
+ lockres->l_name);
+
+ ocfs2_wait_on_busy_lock(lockres);
+out:
+ return 0;
+}
+
+static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres);
+
+/* Mark the lockres as being dropped. It will no longer be
+ * queued if blocking, but we still may have to wait on it
+ * being dequeued from the downconvert thread before we can consider
+ * it safe to drop.
+ *
+ * You can *not* attempt to call cluster_lock on this lockres anymore. */
+void ocfs2_mark_lockres_freeing(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres)
+{
+ int status;
+ struct ocfs2_mask_waiter mw;
+ unsigned long flags, flags2;
+
+ ocfs2_init_mask_waiter(&mw);
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ lockres->l_flags |= OCFS2_LOCK_FREEING;
+ if (lockres->l_flags & OCFS2_LOCK_QUEUED && current == osb->dc_task) {
+ /*
+ * We know the downconvert is queued but not in progress
+ * because we are the downconvert thread and processing
+ * different lock. So we can just remove the lock from the
+ * queue. This is not only an optimization but also a way
+ * to avoid the following deadlock:
+ * ocfs2_dentry_post_unlock()
+ * ocfs2_dentry_lock_put()
+ * ocfs2_drop_dentry_lock()
+ * iput()
+ * ocfs2_evict_inode()
+ * ocfs2_clear_inode()
+ * ocfs2_mark_lockres_freeing()
+ * ... blocks waiting for OCFS2_LOCK_QUEUED
+ * since we are the downconvert thread which
+ * should clear the flag.
+ */
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ spin_lock_irqsave(&osb->dc_task_lock, flags2);
+ list_del_init(&lockres->l_blocked_list);
+ osb->blocked_lock_count--;
+ spin_unlock_irqrestore(&osb->dc_task_lock, flags2);
+ /*
+ * Warn if we recurse into another post_unlock call. Strictly
+ * speaking it isn't a problem but we need to be careful if
+ * that happens (stack overflow, deadlocks, ...) so warn if
+ * ocfs2 grows a path for which this can happen.
+ */
+ WARN_ON_ONCE(lockres->l_ops->post_unlock);
+ /* Since the lock is freeing we don't do much in the fn below */
+ ocfs2_process_blocked_lock(osb, lockres);
+ return;
+ }
+ while (lockres->l_flags & OCFS2_LOCK_QUEUED) {
+ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ mlog(0, "Waiting on lockres %s\n", lockres->l_name);
+
+ status = ocfs2_wait_for_mask(&mw);
+ if (status)
+ mlog_errno(status);
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ }
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+}
+
+void ocfs2_simple_drop_lockres(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres)
+{
+ int ret;
+
+ ocfs2_mark_lockres_freeing(osb, lockres);
+ ret = ocfs2_drop_lock(osb, lockres);
+ if (ret)
+ mlog_errno(ret);
+}
+
+static void ocfs2_drop_osb_locks(struct ocfs2_super *osb)
+{
+ ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres);
+ ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres);
+ ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres);
+ ocfs2_simple_drop_lockres(osb, &osb->osb_orphan_scan.os_lockres);
+}
+
+int ocfs2_drop_inode_locks(struct inode *inode)
+{
+ int status, err;
+
+ /* No need to call ocfs2_mark_lockres_freeing here -
+ * ocfs2_clear_inode has done it for us. */
+
+ err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
+ &OCFS2_I(inode)->ip_open_lockres);
+ if (err < 0)
+ mlog_errno(err);
+
+ status = err;
+
+ err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
+ &OCFS2_I(inode)->ip_inode_lockres);
+ if (err < 0)
+ mlog_errno(err);
+ if (err < 0 && !status)
+ status = err;
+
+ err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb),
+ &OCFS2_I(inode)->ip_rw_lockres);
+ if (err < 0)
+ mlog_errno(err);
+ if (err < 0 && !status)
+ status = err;
+
+ return status;
+}
+
+static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres,
+ int new_level)
+{
+ assert_spin_locked(&lockres->l_lock);
+
+ BUG_ON(lockres->l_blocking <= DLM_LOCK_NL);
+
+ if (lockres->l_level <= new_level) {
+ mlog(ML_ERROR, "lockres %s, lvl %d <= %d, blcklst %d, mask %d, "
+ "type %d, flags 0x%lx, hold %d %d, act %d %d, req %d, "
+ "block %d, pgen %d\n", lockres->l_name, lockres->l_level,
+ new_level, list_empty(&lockres->l_blocked_list),
+ list_empty(&lockres->l_mask_waiters), lockres->l_type,
+ lockres->l_flags, lockres->l_ro_holders,
+ lockres->l_ex_holders, lockres->l_action,
+ lockres->l_unlock_action, lockres->l_requested,
+ lockres->l_blocking, lockres->l_pending_gen);
+ BUG();
+ }
+
+ mlog(ML_BASTS, "lockres %s, level %d => %d, blocking %d\n",
+ lockres->l_name, lockres->l_level, new_level, lockres->l_blocking);
+
+ lockres->l_action = OCFS2_AST_DOWNCONVERT;
+ lockres->l_requested = new_level;
+ lockres_or_flags(lockres, OCFS2_LOCK_BUSY);
+ return lockres_set_pending(lockres);
+}
+
+static int ocfs2_downconvert_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ int new_level,
+ int lvb,
+ unsigned int generation)
+{
+ int ret;
+ u32 dlm_flags = DLM_LKF_CONVERT;
+
+ mlog(ML_BASTS, "lockres %s, level %d => %d\n", lockres->l_name,
+ lockres->l_level, new_level);
+
+ if (lvb)
+ dlm_flags |= DLM_LKF_VALBLK;
+
+ ret = ocfs2_dlm_lock(osb->cconn,
+ new_level,
+ &lockres->l_lksb,
+ dlm_flags,
+ lockres->l_name,
+ OCFS2_LOCK_ID_MAX_LEN - 1);
+ lockres_clear_pending(lockres, generation, osb);
+ if (ret) {
+ ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres);
+ ocfs2_recover_from_dlm_error(lockres, 1);
+ goto bail;
+ }
+
+ ret = 0;
+bail:
+ return ret;
+}
+
+/* returns 1 when the caller should unlock and call ocfs2_dlm_unlock */
+static int ocfs2_prepare_cancel_convert(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres)
+{
+ assert_spin_locked(&lockres->l_lock);
+
+ if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) {
+ /* If we're already trying to cancel a lock conversion
+ * then just drop the spinlock and allow the caller to
+ * requeue this lock. */
+ mlog(ML_BASTS, "lockres %s, skip convert\n", lockres->l_name);
+ return 0;
+ }
+
+ /* were we in a convert when we got the bast fire? */
+ BUG_ON(lockres->l_action != OCFS2_AST_CONVERT &&
+ lockres->l_action != OCFS2_AST_DOWNCONVERT);
+ /* set things up for the unlockast to know to just
+ * clear out the ast_action and unset busy, etc. */
+ lockres->l_unlock_action = OCFS2_UNLOCK_CANCEL_CONVERT;
+
+ mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_BUSY),
+ "lock %s, invalid flags: 0x%lx\n",
+ lockres->l_name, lockres->l_flags);
+
+ mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
+
+ return 1;
+}
+
+static int ocfs2_cancel_convert(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres)
+{
+ int ret;
+
+ ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb,
+ DLM_LKF_CANCEL);
+ if (ret) {
+ ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres);
+ ocfs2_recover_from_dlm_error(lockres, 0);
+ }
+
+ mlog(ML_BASTS, "lockres %s\n", lockres->l_name);
+
+ return ret;
+}
+
+static int ocfs2_unblock_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres,
+ struct ocfs2_unblock_ctl *ctl)
+{
+ unsigned long flags;
+ int blocking;
+ int new_level;
+ int level;
+ int ret = 0;
+ int set_lvb = 0;
+ unsigned int gen;
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+
+recheck:
+ /*
+ * Is it still blocking? If not, we have no more work to do.
+ */
+ if (!(lockres->l_flags & OCFS2_LOCK_BLOCKED)) {
+ BUG_ON(lockres->l_blocking != DLM_LOCK_NL);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ ret = 0;
+ goto leave;
+ }
+
+ if (lockres->l_flags & OCFS2_LOCK_BUSY) {
+ /* XXX
+ * This is a *big* race. The OCFS2_LOCK_PENDING flag
+ * exists entirely for one reason - another thread has set
+ * OCFS2_LOCK_BUSY, but has *NOT* yet called dlm_lock().
+ *
+ * If we do ocfs2_cancel_convert() before the other thread
+ * calls dlm_lock(), our cancel will do nothing. We will
+ * get no ast, and we will have no way of knowing the
+ * cancel failed. Meanwhile, the other thread will call
+ * into dlm_lock() and wait...forever.
+ *
+ * Why forever? Because another node has asked for the
+ * lock first; that's why we're here in unblock_lock().
+ *
+ * The solution is OCFS2_LOCK_PENDING. When PENDING is
+ * set, we just requeue the unblock. Only when the other
+ * thread has called dlm_lock() and cleared PENDING will
+ * we then cancel their request.
+ *
+ * All callers of dlm_lock() must set OCFS2_DLM_PENDING
+ * at the same time they set OCFS2_DLM_BUSY. They must
+ * clear OCFS2_DLM_PENDING after dlm_lock() returns.
+ */
+ if (lockres->l_flags & OCFS2_LOCK_PENDING) {
+ mlog(ML_BASTS, "lockres %s, ReQ: Pending\n",
+ lockres->l_name);
+ goto leave_requeue;
+ }
+
+ ctl->requeue = 1;
+ ret = ocfs2_prepare_cancel_convert(osb, lockres);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ if (ret) {
+ ret = ocfs2_cancel_convert(osb, lockres);
+ if (ret < 0)
+ mlog_errno(ret);
+ }
+ goto leave;
+ }
+
+ /*
+ * This prevents livelocks. OCFS2_LOCK_UPCONVERT_FINISHING flag is
+ * set when the ast is received for an upconvert just before the
+ * OCFS2_LOCK_BUSY flag is cleared. Now if the fs received a bast
+ * on the heels of the ast, we want to delay the downconvert just
+ * enough to allow the up requestor to do its task. Because this
+ * lock is in the blocked queue, the lock will be downconverted
+ * as soon as the requestor is done with the lock.
+ */
+ if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING)
+ goto leave_requeue;
+
+ /*
+ * How can we block and yet be at NL? We were trying to upconvert
+ * from NL and got canceled. The code comes back here, and now
+ * we notice and clear BLOCKING.
+ */
+ if (lockres->l_level == DLM_LOCK_NL) {
+ BUG_ON(lockres->l_ex_holders || lockres->l_ro_holders);
+ mlog(ML_BASTS, "lockres %s, Aborting dc\n", lockres->l_name);
+ lockres->l_blocking = DLM_LOCK_NL;
+ lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ goto leave;
+ }
+
+ /* if we're blocking an exclusive and we have *any* holders,
+ * then requeue. */
+ if ((lockres->l_blocking == DLM_LOCK_EX)
+ && (lockres->l_ex_holders || lockres->l_ro_holders)) {
+ mlog(ML_BASTS, "lockres %s, ReQ: EX/PR Holders %u,%u\n",
+ lockres->l_name, lockres->l_ex_holders,
+ lockres->l_ro_holders);
+ goto leave_requeue;
+ }
+
+ /* If it's a PR we're blocking, then only
+ * requeue if we've got any EX holders */
+ if (lockres->l_blocking == DLM_LOCK_PR &&
+ lockres->l_ex_holders) {
+ mlog(ML_BASTS, "lockres %s, ReQ: EX Holders %u\n",
+ lockres->l_name, lockres->l_ex_holders);
+ goto leave_requeue;
+ }
+
+ /*
+ * Can we get a lock in this state if the holder counts are
+ * zero? The meta data unblock code used to check this.
+ */
+ if ((lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH)
+ && (lockres->l_flags & OCFS2_LOCK_REFRESHING)) {
+ mlog(ML_BASTS, "lockres %s, ReQ: Lock Refreshing\n",
+ lockres->l_name);
+ goto leave_requeue;
+ }
+
+ new_level = ocfs2_highest_compat_lock_level(lockres->l_blocking);
+
+ if (lockres->l_ops->check_downconvert
+ && !lockres->l_ops->check_downconvert(lockres, new_level)) {
+ mlog(ML_BASTS, "lockres %s, ReQ: Checkpointing\n",
+ lockres->l_name);
+ goto leave_requeue;
+ }
+
+ /* If we get here, then we know that there are no more
+ * incompatible holders (and anyone asking for an incompatible
+ * lock is blocked). We can now downconvert the lock */
+ if (!lockres->l_ops->downconvert_worker)
+ goto downconvert;
+
+ /* Some lockres types want to do a bit of work before
+ * downconverting a lock. Allow that here. The worker function
+ * may sleep, so we save off a copy of what we're blocking as
+ * it may change while we're not holding the spin lock. */
+ blocking = lockres->l_blocking;
+ level = lockres->l_level;
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ ctl->unblock_action = lockres->l_ops->downconvert_worker(lockres, blocking);
+
+ if (ctl->unblock_action == UNBLOCK_STOP_POST) {
+ mlog(ML_BASTS, "lockres %s, UNBLOCK_STOP_POST\n",
+ lockres->l_name);
+ goto leave;
+ }
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ if ((blocking != lockres->l_blocking) || (level != lockres->l_level)) {
+ /* If this changed underneath us, then we can't drop
+ * it just yet. */
+ mlog(ML_BASTS, "lockres %s, block=%d:%d, level=%d:%d, "
+ "Recheck\n", lockres->l_name, blocking,
+ lockres->l_blocking, level, lockres->l_level);
+ goto recheck;
+ }
+
+downconvert:
+ ctl->requeue = 0;
+
+ if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) {
+ if (lockres->l_level == DLM_LOCK_EX)
+ set_lvb = 1;
+
+ /*
+ * We only set the lvb if the lock has been fully
+ * refreshed - otherwise we risk setting stale
+ * data. Otherwise, there's no need to actually clear
+ * out the lvb here as it's value is still valid.
+ */
+ if (set_lvb && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH))
+ lockres->l_ops->set_lvb(lockres);
+ }
+
+ gen = ocfs2_prepare_downconvert(lockres, new_level);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ ret = ocfs2_downconvert_lock(osb, lockres, new_level, set_lvb,
+ gen);
+
+leave:
+ if (ret)
+ mlog_errno(ret);
+ return ret;
+
+leave_requeue:
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+ ctl->requeue = 1;
+
+ return 0;
+}
+
+static int ocfs2_data_convert_worker(struct ocfs2_lock_res *lockres,
+ int blocking)
+{
+ struct inode *inode;
+ struct address_space *mapping;
+ struct ocfs2_inode_info *oi;
+
+ inode = ocfs2_lock_res_inode(lockres);
+ mapping = inode->i_mapping;
+
+ if (S_ISDIR(inode->i_mode)) {
+ oi = OCFS2_I(inode);
+ oi->ip_dir_lock_gen++;
+ mlog(0, "generation: %u\n", oi->ip_dir_lock_gen);
+ goto out;
+ }
+
+ if (!S_ISREG(inode->i_mode))
+ goto out;
+
+ /*
+ * We need this before the filemap_fdatawrite() so that it can
+ * transfer the dirty bit from the PTE to the
+ * page. Unfortunately this means that even for EX->PR
+ * downconverts, we'll lose our mappings and have to build
+ * them up again.
+ */
+ unmap_mapping_range(mapping, 0, 0, 0);
+
+ if (filemap_fdatawrite(mapping)) {
+ mlog(ML_ERROR, "Could not sync inode %llu for downconvert!",
+ (unsigned long long)OCFS2_I(inode)->ip_blkno);
+ }
+ sync_mapping_buffers(mapping);
+ if (blocking == DLM_LOCK_EX) {
+ truncate_inode_pages(mapping, 0);
+ } else {
+ /* We only need to wait on the I/O if we're not also
+ * truncating pages because truncate_inode_pages waits
+ * for us above. We don't truncate pages if we're
+ * blocking anything < EXMODE because we want to keep
+ * them around in that case. */
+ filemap_fdatawait(mapping);
+ }
+
+out:
+ return UNBLOCK_CONTINUE;
+}
+
+static int ocfs2_ci_checkpointed(struct ocfs2_caching_info *ci,
+ struct ocfs2_lock_res *lockres,
+ int new_level)
+{
+ int checkpointed = ocfs2_ci_fully_checkpointed(ci);
+
+ BUG_ON(new_level != DLM_LOCK_NL && new_level != DLM_LOCK_PR);
+ BUG_ON(lockres->l_level != DLM_LOCK_EX && !checkpointed);
+
+ if (checkpointed)
+ return 1;
+
+ ocfs2_start_checkpoint(OCFS2_SB(ocfs2_metadata_cache_get_super(ci)));
+ return 0;
+}
+
+static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres,
+ int new_level)
+{
+ struct inode *inode = ocfs2_lock_res_inode(lockres);
+
+ return ocfs2_ci_checkpointed(INODE_CACHE(inode), lockres, new_level);
+}
+
+static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres)
+{
+ struct inode *inode = ocfs2_lock_res_inode(lockres);
+
+ __ocfs2_stuff_meta_lvb(inode);
+}
+
+/*
+ * Does the final reference drop on our dentry lock. Right now this
+ * happens in the downconvert thread, but we could choose to simplify the
+ * dlmglue API and push these off to the ocfs2_wq in the future.
+ */
+static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres)
+{
+ struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
+ ocfs2_dentry_lock_put(osb, dl);
+}
+
+/*
+ * d_delete() matching dentries before the lock downconvert.
+ *
+ * At this point, any process waiting to destroy the
+ * dentry_lock due to last ref count is stopped by the
+ * OCFS2_LOCK_QUEUED flag.
+ *
+ * We have two potential problems
+ *
+ * 1) If we do the last reference drop on our dentry_lock (via dput)
+ * we'll wind up in ocfs2_release_dentry_lock(), waiting on
+ * the downconvert to finish. Instead we take an elevated
+ * reference and push the drop until after we've completed our
+ * unblock processing.
+ *
+ * 2) There might be another process with a final reference,
+ * waiting on us to finish processing. If this is the case, we
+ * detect it and exit out - there's no more dentries anyway.
+ */
+static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres,
+ int blocking)
+{
+ struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres);
+ struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode);
+ struct dentry *dentry;
+ unsigned long flags;
+ int extra_ref = 0;
+
+ /*
+ * This node is blocking another node from getting a read
+ * lock. This happens when we've renamed within a
+ * directory. We've forced the other nodes to d_delete(), but
+ * we never actually dropped our lock because it's still
+ * valid. The downconvert code will retain a PR for this node,
+ * so there's no further work to do.
+ */
+ if (blocking == DLM_LOCK_PR)
+ return UNBLOCK_CONTINUE;
+
+ /*
+ * Mark this inode as potentially orphaned. The code in
+ * ocfs2_delete_inode() will figure out whether it actually
+ * needs to be freed or not.
+ */
+ spin_lock(&oi->ip_lock);
+ oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED;
+ spin_unlock(&oi->ip_lock);
+
+ /*
+ * Yuck. We need to make sure however that the check of
+ * OCFS2_LOCK_FREEING and the extra reference are atomic with
+ * respect to a reference decrement or the setting of that
+ * flag.
+ */
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ spin_lock(&dentry_attach_lock);
+ if (!(lockres->l_flags & OCFS2_LOCK_FREEING)
+ && dl->dl_count) {
+ dl->dl_count++;
+ extra_ref = 1;
+ }
+ spin_unlock(&dentry_attach_lock);
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ mlog(0, "extra_ref = %d\n", extra_ref);
+
+ /*
+ * We have a process waiting on us in ocfs2_dentry_iput(),
+ * which means we can't have any more outstanding
+ * aliases. There's no need to do any more work.
+ */
+ if (!extra_ref)
+ return UNBLOCK_CONTINUE;
+
+ spin_lock(&dentry_attach_lock);
+ while (1) {
+ dentry = ocfs2_find_local_alias(dl->dl_inode,
+ dl->dl_parent_blkno, 1);
+ if (!dentry)
+ break;
+ spin_unlock(&dentry_attach_lock);
+
+ if (S_ISDIR(dl->dl_inode->i_mode))
+ shrink_dcache_parent(dentry);
+
+ mlog(0, "d_delete(%pd);\n", dentry);
+
+ /*
+ * The following dcache calls may do an
+ * iput(). Normally we don't want that from the
+ * downconverting thread, but in this case it's ok
+ * because the requesting node already has an
+ * exclusive lock on the inode, so it can't be queued
+ * for a downconvert.
+ */
+ d_delete(dentry);
+ dput(dentry);
+
+ spin_lock(&dentry_attach_lock);
+ }
+ spin_unlock(&dentry_attach_lock);
+
+ /*
+ * If we are the last holder of this dentry lock, there is no
+ * reason to downconvert so skip straight to the unlock.
+ */
+ if (dl->dl_count == 1)
+ return UNBLOCK_STOP_POST;
+
+ return UNBLOCK_CONTINUE_POST;
+}
+
+static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres,
+ int new_level)
+{
+ struct ocfs2_refcount_tree *tree =
+ ocfs2_lock_res_refcount_tree(lockres);
+
+ return ocfs2_ci_checkpointed(&tree->rf_ci, lockres, new_level);
+}
+
+static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres,
+ int blocking)
+{
+ struct ocfs2_refcount_tree *tree =
+ ocfs2_lock_res_refcount_tree(lockres);
+
+ ocfs2_metadata_cache_purge(&tree->rf_ci);
+
+ return UNBLOCK_CONTINUE;
+}
+
+static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres)
+{
+ struct ocfs2_qinfo_lvb *lvb;
+ struct ocfs2_mem_dqinfo *oinfo = ocfs2_lock_res_qinfo(lockres);
+ struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
+ oinfo->dqi_gi.dqi_type);
+
+ lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+ lvb->lvb_version = OCFS2_QINFO_LVB_VERSION;
+ lvb->lvb_bgrace = cpu_to_be32(info->dqi_bgrace);
+ lvb->lvb_igrace = cpu_to_be32(info->dqi_igrace);
+ lvb->lvb_syncms = cpu_to_be32(oinfo->dqi_syncms);
+ lvb->lvb_blocks = cpu_to_be32(oinfo->dqi_gi.dqi_blocks);
+ lvb->lvb_free_blk = cpu_to_be32(oinfo->dqi_gi.dqi_free_blk);
+ lvb->lvb_free_entry = cpu_to_be32(oinfo->dqi_gi.dqi_free_entry);
+}
+
+void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex)
+{
+ struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
+ struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+
+ if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb))
+ ocfs2_cluster_unlock(osb, lockres, level);
+}
+
+static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo)
+{
+ struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb,
+ oinfo->dqi_gi.dqi_type);
+ struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
+ struct ocfs2_qinfo_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb);
+ struct buffer_head *bh = NULL;
+ struct ocfs2_global_disk_dqinfo *gdinfo;
+ int status = 0;
+
+ if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) &&
+ lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) {
+ info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace);
+ info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace);
+ oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms);
+ oinfo->dqi_gi.dqi_blocks = be32_to_cpu(lvb->lvb_blocks);
+ oinfo->dqi_gi.dqi_free_blk = be32_to_cpu(lvb->lvb_free_blk);
+ oinfo->dqi_gi.dqi_free_entry =
+ be32_to_cpu(lvb->lvb_free_entry);
+ } else {
+ status = ocfs2_read_quota_phys_block(oinfo->dqi_gqinode,
+ oinfo->dqi_giblk, &bh);
+ if (status) {
+ mlog_errno(status);
+ goto bail;
+ }
+ gdinfo = (struct ocfs2_global_disk_dqinfo *)
+ (bh->b_data + OCFS2_GLOBAL_INFO_OFF);
+ info->dqi_bgrace = le32_to_cpu(gdinfo->dqi_bgrace);
+ info->dqi_igrace = le32_to_cpu(gdinfo->dqi_igrace);
+ oinfo->dqi_syncms = le32_to_cpu(gdinfo->dqi_syncms);
+ oinfo->dqi_gi.dqi_blocks = le32_to_cpu(gdinfo->dqi_blocks);
+ oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(gdinfo->dqi_free_blk);
+ oinfo->dqi_gi.dqi_free_entry =
+ le32_to_cpu(gdinfo->dqi_free_entry);
+ brelse(bh);
+ ocfs2_track_lock_refresh(lockres);
+ }
+
+bail:
+ return status;
+}
+
+/* Lock quota info, this function expects at least shared lock on the quota file
+ * so that we can safely refresh quota info from disk. */
+int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex)
+{
+ struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock;
+ struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb);
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ int status = 0;
+
+ /* On RO devices, locking really isn't needed... */
+ if (ocfs2_is_hard_readonly(osb)) {
+ if (ex)
+ status = -EROFS;
+ goto bail;
+ }
+ if (ocfs2_mount_local(osb))
+ goto bail;
+
+ status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
+ if (status < 0) {
+ mlog_errno(status);
+ goto bail;
+ }
+ if (!ocfs2_should_refresh_lock_res(lockres))
+ goto bail;
+ /* OK, we have the lock but we need to refresh the quota info */
+ status = ocfs2_refresh_qinfo(oinfo);
+ if (status)
+ ocfs2_qinfo_unlock(oinfo, ex);
+ ocfs2_complete_lock_res_refresh(lockres, status);
+bail:
+ return status;
+}
+
+int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex)
+{
+ int status;
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
+ struct ocfs2_super *osb = lockres->l_priv;
+
+
+ if (ocfs2_is_hard_readonly(osb))
+ return -EROFS;
+
+ if (ocfs2_mount_local(osb))
+ return 0;
+
+ status = ocfs2_cluster_lock(osb, lockres, level, 0, 0);
+ if (status < 0)
+ mlog_errno(status);
+
+ return status;
+}
+
+void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex)
+{
+ int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR;
+ struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres;
+ struct ocfs2_super *osb = lockres->l_priv;
+
+ if (!ocfs2_mount_local(osb))
+ ocfs2_cluster_unlock(osb, lockres, level);
+}
+
+static void ocfs2_process_blocked_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres)
+{
+ int status;
+ struct ocfs2_unblock_ctl ctl = {0, 0,};
+ unsigned long flags;
+
+ /* Our reference to the lockres in this function can be
+ * considered valid until we remove the OCFS2_LOCK_QUEUED
+ * flag. */
+
+ BUG_ON(!lockres);
+ BUG_ON(!lockres->l_ops);
+
+ mlog(ML_BASTS, "lockres %s blocked\n", lockres->l_name);
+
+ /* Detect whether a lock has been marked as going away while
+ * the downconvert thread was processing other things. A lock can
+ * still be marked with OCFS2_LOCK_FREEING after this check,
+ * but short circuiting here will still save us some
+ * performance. */
+ spin_lock_irqsave(&lockres->l_lock, flags);
+ if (lockres->l_flags & OCFS2_LOCK_FREEING)
+ goto unqueue;
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ status = ocfs2_unblock_lock(osb, lockres, &ctl);
+ if (status < 0)
+ mlog_errno(status);
+
+ spin_lock_irqsave(&lockres->l_lock, flags);
+unqueue:
+ if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) {
+ lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED);
+ } else
+ ocfs2_schedule_blocked_lock(osb, lockres);
+
+ mlog(ML_BASTS, "lockres %s, requeue = %s.\n", lockres->l_name,
+ ctl.requeue ? "yes" : "no");
+ spin_unlock_irqrestore(&lockres->l_lock, flags);
+
+ if (ctl.unblock_action != UNBLOCK_CONTINUE
+ && lockres->l_ops->post_unlock)
+ lockres->l_ops->post_unlock(osb, lockres);
+}
+
+static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb,
+ struct ocfs2_lock_res *lockres)
+{
+ unsigned long flags;
+
+ assert_spin_locked(&lockres->l_lock);
+
+ if (lockres->l_flags & OCFS2_LOCK_FREEING) {
+ /* Do not schedule a lock for downconvert when it's on
+ * the way to destruction - any nodes wanting access
+ * to the resource will get it soon. */
+ mlog(ML_BASTS, "lockres %s won't be scheduled: flags 0x%lx\n",
+ lockres->l_name, lockres->l_flags);
+ return;
+ }
+
+ lockres_or_flags(lockres, OCFS2_LOCK_QUEUED);
+
+ spin_lock_irqsave(&osb->dc_task_lock, flags);
+ if (list_empty(&lockres->l_blocked_list)) {
+ list_add_tail(&lockres->l_blocked_list,
+ &osb->blocked_lock_list);
+ osb->blocked_lock_count++;
+ }
+ spin_unlock_irqrestore(&osb->dc_task_lock, flags);
+}
+
+static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb)
+{
+ unsigned long processed;
+ unsigned long flags;
+ struct ocfs2_lock_res *lockres;
+
+ spin_lock_irqsave(&osb->dc_task_lock, flags);
+ /* grab this early so we know to try again if a state change and
+ * wake happens part-way through our work */
+ osb->dc_work_sequence = osb->dc_wake_sequence;
+
+ processed = osb->blocked_lock_count;
+ while (processed) {
+ BUG_ON(list_empty(&osb->blocked_lock_list));
+
+ lockres = list_entry(osb->blocked_lock_list.next,
+ struct ocfs2_lock_res, l_blocked_list);
+ list_del_init(&lockres->l_blocked_list);
+ osb->blocked_lock_count--;
+ spin_unlock_irqrestore(&osb->dc_task_lock, flags);
+
+ BUG_ON(!processed);
+ processed--;
+
+ ocfs2_process_blocked_lock(osb, lockres);
+
+ spin_lock_irqsave(&osb->dc_task_lock, flags);
+ }
+ spin_unlock_irqrestore(&osb->dc_task_lock, flags);
+}
+
+static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb)
+{
+ int empty = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&osb->dc_task_lock, flags);
+ if (list_empty(&osb->blocked_lock_list))
+ empty = 1;
+
+ spin_unlock_irqrestore(&osb->dc_task_lock, flags);
+ return empty;
+}
+
+static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb)
+{
+ int should_wake = 0;
+ unsigned long flags;
+
+ spin_lock_irqsave(&osb->dc_task_lock, flags);
+ if (osb->dc_work_sequence != osb->dc_wake_sequence)
+ should_wake = 1;
+ spin_unlock_irqrestore(&osb->dc_task_lock, flags);
+
+ return should_wake;
+}
+
+static int ocfs2_downconvert_thread(void *arg)
+{
+ int status = 0;
+ struct ocfs2_super *osb = arg;
+
+ /* only quit once we've been asked to stop and there is no more
+ * work available */
+ while (!(kthread_should_stop() &&
+ ocfs2_downconvert_thread_lists_empty(osb))) {
+
+ wait_event_interruptible(osb->dc_event,
+ ocfs2_downconvert_thread_should_wake(osb) ||
+ kthread_should_stop());
+
+ mlog(0, "downconvert_thread: awoken\n");
+
+ ocfs2_downconvert_thread_do_work(osb);
+ }
+
+ osb->dc_task = NULL;
+ return status;
+}
+
+void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&osb->dc_task_lock, flags);
+ /* make sure the voting thread gets a swipe at whatever changes
+ * the caller may have made to the voting state */
+ osb->dc_wake_sequence++;
+ spin_unlock_irqrestore(&osb->dc_task_lock, flags);
+ wake_up(&osb->dc_event);
+}
Code Review / kvmfornfv.git / blobdiff