| /* -*- 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. |
| */ |
| lockres_or_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); |
| |
| 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 */ |
| INIT_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) |
| { |
| unsigned long flags; |
| int ret = 0; |
| |
| spin_lock_irqsave(&lockres->l_lock, flags); |
| 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); |
| } |
| 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 */ |
| INIT_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; |
| |
| 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; |
| } |
| |
| 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; |
| if (lockres_remove_mask_waiter(lockres, &mw)) |
| ret = -EAGAIN; |
| else |
| 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(inode->i_uid); |
| lvb->lvb_igid = cpu_to_be32(inode->i_gid); |
| 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); |
| |
| inode->i_uid = be32_to_cpu(lvb->lvb_iuid); |
| inode->i_gid = 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 && status != -EIOCBRETRY) |
| 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 < 0) { |
| ocfs2_cluster_unlock(osb, lockres, level); |
| mlog_errno(status); |
| goto bail; |
| } |
| 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) |
| { |
| int ret; |
| struct ocfs2_dlm_seq_priv *priv; |
| struct seq_file *seq; |
| struct ocfs2_super *osb; |
| |
| priv = kzalloc(sizeof(struct ocfs2_dlm_seq_priv), GFP_KERNEL); |
| if (!priv) { |
| ret = -ENOMEM; |
| mlog_errno(ret); |
| goto out; |
| } |
| 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); |
| |
| ret = seq_open(file, &ocfs2_dlm_seq_ops); |
| if (ret) { |
| kfree(priv); |
| mlog_errno(ret); |
| goto out; |
| } |
| |
| seq = file->private_data; |
| seq->private = priv; |
| |
| ocfs2_add_lockres_tracking(&priv->p_iter_res, |
| priv->p_dlm_debug); |
| |
| out: |
| return ret; |
| } |
| |
| 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->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(&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; |
| } |
| |
| /* 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_lock_res *lockres) |
| { |
| int status; |
| struct ocfs2_mask_waiter mw; |
| unsigned long flags; |
| |
| ocfs2_init_mask_waiter(&mw); |
| |
| spin_lock_irqsave(&lockres->l_lock, flags); |
| lockres->l_flags |= OCFS2_LOCK_FREEING; |
| 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(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); |
| |
| mlog(0, "d_delete(%.*s);\n", dentry->d_name.len, |
| dentry->d_name.name); |
| |
| /* |
| * 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) |
| { |
| 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(&osb->dc_task_lock); |
| if (list_empty(&lockres->l_blocked_list)) { |
| list_add_tail(&lockres->l_blocked_list, |
| &osb->blocked_lock_list); |
| osb->blocked_lock_count++; |
| } |
| spin_unlock(&osb->dc_task_lock); |
| } |
| |
| static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb) |
| { |
| unsigned long processed; |
| struct ocfs2_lock_res *lockres; |
| |
| spin_lock(&osb->dc_task_lock); |
| /* 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; |
| /* |
| * blocked lock processing in this loop might call iput which can |
| * remove items off osb->blocked_lock_list. Downconvert up to |
| * 'processed' number of locks, but stop short if we had some |
| * removed in ocfs2_mark_lockres_freeing when downconverting. |
| */ |
| while (processed && !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(&osb->dc_task_lock); |
| |
| BUG_ON(!processed); |
| processed--; |
| |
| ocfs2_process_blocked_lock(osb, lockres); |
| |
| spin_lock(&osb->dc_task_lock); |
| } |
| spin_unlock(&osb->dc_task_lock); |
| } |
| |
| static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb) |
| { |
| int empty = 0; |
| |
| spin_lock(&osb->dc_task_lock); |
| if (list_empty(&osb->blocked_lock_list)) |
| empty = 1; |
| |
| spin_unlock(&osb->dc_task_lock); |
| return empty; |
| } |
| |
| static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb) |
| { |
| int should_wake = 0; |
| |
| spin_lock(&osb->dc_task_lock); |
| if (osb->dc_work_sequence != osb->dc_wake_sequence) |
| should_wake = 1; |
| spin_unlock(&osb->dc_task_lock); |
| |
| 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) |
| { |
| spin_lock(&osb->dc_task_lock); |
| /* 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(&osb->dc_task_lock); |
| wake_up(&osb->dc_event); |
| } |