diff options
Diffstat (limited to 'fs/gfs2/locking/dlm/lock.c')
| -rw-r--r-- | fs/gfs2/locking/dlm/lock.c | 708 |
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); -} - |
