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path: root/fs/gfs2/locking/dlm/lock.c
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Diffstat (limited to 'fs/gfs2/locking/dlm/lock.c')
-rw-r--r--fs/gfs2/locking/dlm/lock.c708
1 files changed, 0 insertions, 708 deletions
diff --git a/fs/gfs2/locking/dlm/lock.c b/fs/gfs2/locking/dlm/lock.c
deleted file mode 100644
index 2482c9047505..000000000000
--- a/fs/gfs2/locking/dlm/lock.c
+++ /dev/null
@@ -1,708 +0,0 @@
-/*
- * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
- * Copyright (C) 2004-2005 Red Hat, Inc. All rights reserved.
- *
- * This copyrighted material is made available to anyone wishing to use,
- * modify, copy, or redistribute it subject to the terms and conditions
- * of the GNU General Public License version 2.
- */
-
-#include "lock_dlm.h"
-
-static char junk_lvb[GDLM_LVB_SIZE];
-
-
-/* convert dlm lock-mode to gfs lock-state */
-
-static s16 gdlm_make_lmstate(s16 dlmmode)
-{
- switch (dlmmode) {
- case DLM_LOCK_IV:
- case DLM_LOCK_NL:
- return LM_ST_UNLOCKED;
- case DLM_LOCK_EX:
- return LM_ST_EXCLUSIVE;
- case DLM_LOCK_CW:
- return LM_ST_DEFERRED;
- case DLM_LOCK_PR:
- return LM_ST_SHARED;
- }
- gdlm_assert(0, "unknown DLM mode %d", dlmmode);
- return -1;
-}
-
-/* A lock placed on this queue is re-submitted to DLM as soon as the lock_dlm
- thread gets to it. */
-
-static void queue_submit(struct gdlm_lock *lp)
-{
- struct gdlm_ls *ls = lp->ls;
-
- spin_lock(&ls->async_lock);
- list_add_tail(&lp->delay_list, &ls->submit);
- spin_unlock(&ls->async_lock);
- wake_up(&ls->thread_wait);
-}
-
-static void wake_up_ast(struct gdlm_lock *lp)
-{
- clear_bit(LFL_AST_WAIT, &lp->flags);
- smp_mb__after_clear_bit();
- wake_up_bit(&lp->flags, LFL_AST_WAIT);
-}
-
-static void gdlm_delete_lp(struct gdlm_lock *lp)
-{
- struct gdlm_ls *ls = lp->ls;
-
- spin_lock(&ls->async_lock);
- if (!list_empty(&lp->delay_list))
- list_del_init(&lp->delay_list);
- ls->all_locks_count--;
- spin_unlock(&ls->async_lock);
-
- kfree(lp);
-}
-
-static void gdlm_queue_delayed(struct gdlm_lock *lp)
-{
- struct gdlm_ls *ls = lp->ls;
-
- spin_lock(&ls->async_lock);
- list_add_tail(&lp->delay_list, &ls->delayed);
- spin_unlock(&ls->async_lock);
-}
-
-static void process_complete(struct gdlm_lock *lp)
-{
- struct gdlm_ls *ls = lp->ls;
- struct lm_async_cb acb;
-
- memset(&acb, 0, sizeof(acb));
-
- if (lp->lksb.sb_status == -DLM_ECANCEL) {
- log_info("complete dlm cancel %x,%llx flags %lx",
- lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number,
- lp->flags);
-
- lp->req = lp->cur;
- acb.lc_ret |= LM_OUT_CANCELED;
- if (lp->cur == DLM_LOCK_IV)
- lp->lksb.sb_lkid = 0;
- goto out;
- }
-
- if (test_and_clear_bit(LFL_DLM_UNLOCK, &lp->flags)) {
- if (lp->lksb.sb_status != -DLM_EUNLOCK) {
- log_info("unlock sb_status %d %x,%llx flags %lx",
- lp->lksb.sb_status, lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number,
- lp->flags);
- return;
- }
-
- lp->cur = DLM_LOCK_IV;
- lp->req = DLM_LOCK_IV;
- lp->lksb.sb_lkid = 0;
-
- if (test_and_clear_bit(LFL_UNLOCK_DELETE, &lp->flags)) {
- gdlm_delete_lp(lp);
- return;
- }
- goto out;
- }
-
- if (lp->lksb.sb_flags & DLM_SBF_VALNOTVALID)
- memset(lp->lksb.sb_lvbptr, 0, GDLM_LVB_SIZE);
-
- if (lp->lksb.sb_flags & DLM_SBF_ALTMODE) {
- if (lp->req == DLM_LOCK_PR)
- lp->req = DLM_LOCK_CW;
- else if (lp->req == DLM_LOCK_CW)
- lp->req = DLM_LOCK_PR;
- }
-
- /*
- * A canceled lock request. The lock was just taken off the delayed
- * list and was never even submitted to dlm.
- */
-
- if (test_and_clear_bit(LFL_CANCEL, &lp->flags)) {
- log_info("complete internal cancel %x,%llx",
- lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number);
- lp->req = lp->cur;
- acb.lc_ret |= LM_OUT_CANCELED;
- goto out;
- }
-
- /*
- * An error occured.
- */
-
- if (lp->lksb.sb_status) {
- /* a "normal" error */
- if ((lp->lksb.sb_status == -EAGAIN) &&
- (lp->lkf & DLM_LKF_NOQUEUE)) {
- lp->req = lp->cur;
- if (lp->cur == DLM_LOCK_IV)
- lp->lksb.sb_lkid = 0;
- goto out;
- }
-
- /* this could only happen with cancels I think */
- log_info("ast sb_status %d %x,%llx flags %lx",
- lp->lksb.sb_status, lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number,
- lp->flags);
- return;
- }
-
- /*
- * This is an AST for an EX->EX conversion for sync_lvb from GFS.
- */
-
- if (test_and_clear_bit(LFL_SYNC_LVB, &lp->flags)) {
- wake_up_ast(lp);
- return;
- }
-
- /*
- * A lock has been demoted to NL because it initially completed during
- * BLOCK_LOCKS. Now it must be requested in the originally requested
- * mode.
- */
-
- if (test_and_clear_bit(LFL_REREQUEST, &lp->flags)) {
- gdlm_assert(lp->req == DLM_LOCK_NL, "%x,%llx",
- lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number);
- gdlm_assert(lp->prev_req > DLM_LOCK_NL, "%x,%llx",
- lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number);
-
- lp->cur = DLM_LOCK_NL;
- lp->req = lp->prev_req;
- lp->prev_req = DLM_LOCK_IV;
- lp->lkf &= ~DLM_LKF_CONVDEADLK;
-
- set_bit(LFL_NOCACHE, &lp->flags);
-
- if (test_bit(DFL_BLOCK_LOCKS, &ls->flags) &&
- !test_bit(LFL_NOBLOCK, &lp->flags))
- gdlm_queue_delayed(lp);
- else
- queue_submit(lp);
- return;
- }
-
- /*
- * A request is granted during dlm recovery. It may be granted
- * because the locks of a failed node were cleared. In that case,
- * there may be inconsistent data beneath this lock and we must wait
- * for recovery to complete to use it. When gfs recovery is done this
- * granted lock will be converted to NL and then reacquired in this
- * granted state.
- */
-
- if (test_bit(DFL_BLOCK_LOCKS, &ls->flags) &&
- !test_bit(LFL_NOBLOCK, &lp->flags) &&
- lp->req != DLM_LOCK_NL) {
-
- lp->cur = lp->req;
- lp->prev_req = lp->req;
- lp->req = DLM_LOCK_NL;
- lp->lkf |= DLM_LKF_CONVERT;
- lp->lkf &= ~DLM_LKF_CONVDEADLK;
-
- log_debug("rereq %x,%llx id %x %d,%d",
- lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number,
- lp->lksb.sb_lkid, lp->cur, lp->req);
-
- set_bit(LFL_REREQUEST, &lp->flags);
- queue_submit(lp);
- return;
- }
-
- /*
- * DLM demoted the lock to NL before it was granted so GFS must be
- * told it cannot cache data for this lock.
- */
-
- if (lp->lksb.sb_flags & DLM_SBF_DEMOTED)
- set_bit(LFL_NOCACHE, &lp->flags);
-
-out:
- /*
- * This is an internal lock_dlm lock
- */
-
- if (test_bit(LFL_INLOCK, &lp->flags)) {
- clear_bit(LFL_NOBLOCK, &lp->flags);
- lp->cur = lp->req;
- wake_up_ast(lp);
- return;
- }
-
- /*
- * Normal completion of a lock request. Tell GFS it now has the lock.
- */
-
- clear_bit(LFL_NOBLOCK, &lp->flags);
- lp->cur = lp->req;
-
- acb.lc_name = lp->lockname;
- acb.lc_ret |= gdlm_make_lmstate(lp->cur);
-
- ls->fscb(ls->sdp, LM_CB_ASYNC, &acb);
-}
-
-static void gdlm_ast(void *astarg)
-{
- struct gdlm_lock *lp = astarg;
- clear_bit(LFL_ACTIVE, &lp->flags);
- process_complete(lp);
-}
-
-static void process_blocking(struct gdlm_lock *lp, int bast_mode)
-{
- struct gdlm_ls *ls = lp->ls;
- unsigned int cb = 0;
-
- switch (gdlm_make_lmstate(bast_mode)) {
- case LM_ST_EXCLUSIVE:
- cb = LM_CB_NEED_E;
- break;
- case LM_ST_DEFERRED:
- cb = LM_CB_NEED_D;
- break;
- case LM_ST_SHARED:
- cb = LM_CB_NEED_S;
- break;
- default:
- gdlm_assert(0, "unknown bast mode %u", bast_mode);
- }
-
- ls->fscb(ls->sdp, cb, &lp->lockname);
-}
-
-
-static void gdlm_bast(void *astarg, int mode)
-{
- struct gdlm_lock *lp = astarg;
-
- if (!mode) {
- printk(KERN_INFO "lock_dlm: bast mode zero %x,%llx\n",
- lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number);
- return;
- }
-
- process_blocking(lp, mode);
-}
-
-/* convert gfs lock-state to dlm lock-mode */
-
-static s16 make_mode(s16 lmstate)
-{
- switch (lmstate) {
- case LM_ST_UNLOCKED:
- return DLM_LOCK_NL;
- case LM_ST_EXCLUSIVE:
- return DLM_LOCK_EX;
- case LM_ST_DEFERRED:
- return DLM_LOCK_CW;
- case LM_ST_SHARED:
- return DLM_LOCK_PR;
- }
- gdlm_assert(0, "unknown LM state %d", lmstate);
- return -1;
-}
-
-
-/* verify agreement with GFS on the current lock state, NB: DLM_LOCK_NL and
- DLM_LOCK_IV are both considered LM_ST_UNLOCKED by GFS. */
-
-static void check_cur_state(struct gdlm_lock *lp, unsigned int cur_state)
-{
- s16 cur = make_mode(cur_state);
- if (lp->cur != DLM_LOCK_IV)
- gdlm_assert(lp->cur == cur, "%d, %d", lp->cur, cur);
-}
-
-static inline unsigned int make_flags(struct gdlm_lock *lp,
- unsigned int gfs_flags,
- s16 cur, s16 req)
-{
- unsigned int lkf = 0;
-
- if (gfs_flags & LM_FLAG_TRY)
- lkf |= DLM_LKF_NOQUEUE;
-
- if (gfs_flags & LM_FLAG_TRY_1CB) {
- lkf |= DLM_LKF_NOQUEUE;
- lkf |= DLM_LKF_NOQUEUEBAST;
- }
-
- if (gfs_flags & LM_FLAG_PRIORITY) {
- lkf |= DLM_LKF_NOORDER;
- lkf |= DLM_LKF_HEADQUE;
- }
-
- if (gfs_flags & LM_FLAG_ANY) {
- if (req == DLM_LOCK_PR)
- lkf |= DLM_LKF_ALTCW;
- else if (req == DLM_LOCK_CW)
- lkf |= DLM_LKF_ALTPR;
- }
-
- if (lp->lksb.sb_lkid != 0) {
- lkf |= DLM_LKF_CONVERT;
- }
-
- if (lp->lvb)
- lkf |= DLM_LKF_VALBLK;
-
- return lkf;
-}
-
-/* make_strname - convert GFS lock numbers to a string */
-
-static inline void make_strname(const struct lm_lockname *lockname,
- struct gdlm_strname *str)
-{
- sprintf(str->name, "%8x%16llx", lockname->ln_type,
- (unsigned long long)lockname->ln_number);
- str->namelen = GDLM_STRNAME_BYTES;
-}
-
-static int gdlm_create_lp(struct gdlm_ls *ls, struct lm_lockname *name,
- struct gdlm_lock **lpp)
-{
- struct gdlm_lock *lp;
-
- lp = kzalloc(sizeof(struct gdlm_lock), GFP_NOFS);
- if (!lp)
- return -ENOMEM;
-
- lp->lockname = *name;
- make_strname(name, &lp->strname);
- lp->ls = ls;
- lp->cur = DLM_LOCK_IV;
- INIT_LIST_HEAD(&lp->delay_list);
-
- spin_lock(&ls->async_lock);
- ls->all_locks_count++;
- spin_unlock(&ls->async_lock);
-
- *lpp = lp;
- return 0;
-}
-
-int gdlm_get_lock(void *lockspace, struct lm_lockname *name,
- void **lockp)
-{
- struct gdlm_lock *lp;
- int error;
-
- error = gdlm_create_lp(lockspace, name, &lp);
-
- *lockp = lp;
- return error;
-}
-
-void gdlm_put_lock(void *lock)
-{
- gdlm_delete_lp(lock);
-}
-
-unsigned int gdlm_do_lock(struct gdlm_lock *lp)
-{
- struct gdlm_ls *ls = lp->ls;
- int error, bast = 1;
-
- /*
- * When recovery is in progress, delay lock requests for submission
- * once recovery is done. Requests for recovery (NOEXP) and unlocks
- * can pass.
- */
-
- if (test_bit(DFL_BLOCK_LOCKS, &ls->flags) &&
- !test_bit(LFL_NOBLOCK, &lp->flags) && lp->req != DLM_LOCK_NL) {
- gdlm_queue_delayed(lp);
- return LM_OUT_ASYNC;
- }
-
- /*
- * Submit the actual lock request.
- */
-
- if (test_bit(LFL_NOBAST, &lp->flags))
- bast = 0;
-
- set_bit(LFL_ACTIVE, &lp->flags);
-
- log_debug("lk %x,%llx id %x %d,%d %x", lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number, lp->lksb.sb_lkid,
- lp->cur, lp->req, lp->lkf);
-
- error = dlm_lock(ls->dlm_lockspace, lp->req, &lp->lksb, lp->lkf,
- lp->strname.name, lp->strname.namelen, 0, gdlm_ast,
- lp, bast ? gdlm_bast : NULL);
-
- if ((error == -EAGAIN) && (lp->lkf & DLM_LKF_NOQUEUE)) {
- lp->lksb.sb_status = -EAGAIN;
- gdlm_ast(lp);
- error = 0;
- }
-
- if (error) {
- log_error("%s: gdlm_lock %x,%llx err=%d cur=%d req=%d lkf=%x "
- "flags=%lx", ls->fsname, lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number, error,
- lp->cur, lp->req, lp->lkf, lp->flags);
- return LM_OUT_ERROR;
- }
- return LM_OUT_ASYNC;
-}
-
-static unsigned int gdlm_do_unlock(struct gdlm_lock *lp)
-{
- struct gdlm_ls *ls = lp->ls;
- unsigned int lkf = 0;
- int error;
-
- set_bit(LFL_DLM_UNLOCK, &lp->flags);
- set_bit(LFL_ACTIVE, &lp->flags);
-
- if (lp->lvb)
- lkf = DLM_LKF_VALBLK;
-
- log_debug("un %x,%llx %x %d %x", lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number,
- lp->lksb.sb_lkid, lp->cur, lkf);
-
- error = dlm_unlock(ls->dlm_lockspace, lp->lksb.sb_lkid, lkf, NULL, lp);
-
- if (error) {
- log_error("%s: gdlm_unlock %x,%llx err=%d cur=%d req=%d lkf=%x "
- "flags=%lx", ls->fsname, lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number, error,
- lp->cur, lp->req, lp->lkf, lp->flags);
- return LM_OUT_ERROR;
- }
- return LM_OUT_ASYNC;
-}
-
-unsigned int gdlm_lock(void *lock, unsigned int cur_state,
- unsigned int req_state, unsigned int flags)
-{
- struct gdlm_lock *lp = lock;
-
- if (req_state == LM_ST_UNLOCKED)
- return gdlm_unlock(lock, cur_state);
-
- if (req_state == LM_ST_UNLOCKED)
- return gdlm_unlock(lock, cur_state);
-
- clear_bit(LFL_DLM_CANCEL, &lp->flags);
- if (flags & LM_FLAG_NOEXP)
- set_bit(LFL_NOBLOCK, &lp->flags);
-
- check_cur_state(lp, cur_state);
- lp->req = make_mode(req_state);
- lp->lkf = make_flags(lp, flags, lp->cur, lp->req);
-
- return gdlm_do_lock(lp);
-}
-
-unsigned int gdlm_unlock(void *lock, unsigned int cur_state)
-{
- struct gdlm_lock *lp = lock;
-
- clear_bit(LFL_DLM_CANCEL, &lp->flags);
- if (lp->cur == DLM_LOCK_IV)
- return 0;
- return gdlm_do_unlock(lp);
-}
-
-void gdlm_cancel(void *lock)
-{
- struct gdlm_lock *lp = lock;
- struct gdlm_ls *ls = lp->ls;
- int error, delay_list = 0;
-
- if (test_bit(LFL_DLM_CANCEL, &lp->flags))
- return;
-
- log_info("gdlm_cancel %x,%llx flags %lx", lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number, lp->flags);
-
- spin_lock(&ls->async_lock);
- if (!list_empty(&lp->delay_list)) {
- list_del_init(&lp->delay_list);
- delay_list = 1;
- }
- spin_unlock(&ls->async_lock);
-
- if (delay_list) {
- set_bit(LFL_CANCEL, &lp->flags);
- set_bit(LFL_ACTIVE, &lp->flags);
- gdlm_ast(lp);
- return;
- }
-
- if (!test_bit(LFL_ACTIVE, &lp->flags) ||
- test_bit(LFL_DLM_UNLOCK, &lp->flags)) {
- log_info("gdlm_cancel skip %x,%llx flags %lx",
- lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number, lp->flags);
- return;
- }
-
- /* the lock is blocked in the dlm */
-
- set_bit(LFL_DLM_CANCEL, &lp->flags);
- set_bit(LFL_ACTIVE, &lp->flags);
-
- error = dlm_unlock(ls->dlm_lockspace, lp->lksb.sb_lkid, DLM_LKF_CANCEL,
- NULL, lp);
-
- log_info("gdlm_cancel rv %d %x,%llx flags %lx", error,
- lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number, lp->flags);
-
- if (error == -EBUSY)
- clear_bit(LFL_DLM_CANCEL, &lp->flags);
-}
-
-static int gdlm_add_lvb(struct gdlm_lock *lp)
-{
- char *lvb;
-
- lvb = kzalloc(GDLM_LVB_SIZE, GFP_NOFS);
- if (!lvb)
- return -ENOMEM;
-
- lp->lksb.sb_lvbptr = lvb;
- lp->lvb = lvb;
- return 0;
-}
-
-static void gdlm_del_lvb(struct gdlm_lock *lp)
-{
- kfree(lp->lvb);
- lp->lvb = NULL;
- lp->lksb.sb_lvbptr = NULL;
-}
-
-static int gdlm_ast_wait(void *word)
-{
- schedule();
- return 0;
-}
-
-/* This can do a synchronous dlm request (requiring a lock_dlm thread to get
- the completion) because gfs won't call hold_lvb() during a callback (from
- the context of a lock_dlm thread). */
-
-static int hold_null_lock(struct gdlm_lock *lp)
-{
- struct gdlm_lock *lpn = NULL;
- int error;
-
- if (lp->hold_null) {
- printk(KERN_INFO "lock_dlm: lvb already held\n");
- return 0;
- }
-
- error = gdlm_create_lp(lp->ls, &lp->lockname, &lpn);
- if (error)
- goto out;
-
- lpn->lksb.sb_lvbptr = junk_lvb;
- lpn->lvb = junk_lvb;
-
- lpn->req = DLM_LOCK_NL;
- lpn->lkf = DLM_LKF_VALBLK | DLM_LKF_EXPEDITE;
- set_bit(LFL_NOBAST, &lpn->flags);
- set_bit(LFL_INLOCK, &lpn->flags);
- set_bit(LFL_AST_WAIT, &lpn->flags);
-
- gdlm_do_lock(lpn);
- wait_on_bit(&lpn->flags, LFL_AST_WAIT, gdlm_ast_wait, TASK_UNINTERRUPTIBLE);
- error = lpn->lksb.sb_status;
- if (error) {
- printk(KERN_INFO "lock_dlm: hold_null_lock dlm error %d\n",
- error);
- gdlm_delete_lp(lpn);
- lpn = NULL;
- }
-out:
- lp->hold_null = lpn;
- return error;
-}
-
-/* This cannot do a synchronous dlm request (requiring a lock_dlm thread to get
- the completion) because gfs may call unhold_lvb() during a callback (from
- the context of a lock_dlm thread) which could cause a deadlock since the
- other lock_dlm thread could be engaged in recovery. */
-
-static void unhold_null_lock(struct gdlm_lock *lp)
-{
- struct gdlm_lock *lpn = lp->hold_null;
-
- gdlm_assert(lpn, "%x,%llx", lp->lockname.ln_type,
- (unsigned long long)lp->lockname.ln_number);
- lpn->lksb.sb_lvbptr = NULL;
- lpn->lvb = NULL;
- set_bit(LFL_UNLOCK_DELETE, &lpn->flags);
- gdlm_do_unlock(lpn);
- lp->hold_null = NULL;
-}
-
-/* Acquire a NL lock because gfs requires the value block to remain
- intact on the resource while the lvb is "held" even if it's holding no locks
- on the resource. */
-
-int gdlm_hold_lvb(void *lock, char **lvbp)
-{
- struct gdlm_lock *lp = lock;
- int error;
-
- error = gdlm_add_lvb(lp);
- if (error)
- return error;
-
- *lvbp = lp->lvb;
-
- error = hold_null_lock(lp);
- if (error)
- gdlm_del_lvb(lp);
-
- return error;
-}
-
-void gdlm_unhold_lvb(void *lock, char *lvb)
-{
- struct gdlm_lock *lp = lock;
-
- unhold_null_lock(lp);
- gdlm_del_lvb(lp);
-}
-
-void gdlm_submit_delayed(struct gdlm_ls *ls)
-{
- struct gdlm_lock *lp, *safe;
-
- spin_lock(&ls->async_lock);
- list_for_each_entry_safe(lp, safe, &ls->delayed, delay_list) {
- list_del_init(&lp->delay_list);
- list_add_tail(&lp->delay_list, &ls->submit);
- }
- spin_unlock(&ls->async_lock);
- wake_up(&ls->thread_wait);
-}
-