| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Mark Fasheh | 11943 | 66.58% | 37 | 23.72% |
| Sunil Mushran | 1085 | 6.05% | 12 | 7.69% |
| Jan Kara | 997 | 5.56% | 4 | 2.56% |
| Gang He | 923 | 5.15% | 11 | 7.05% |
| Joel Becker | 776 | 4.33% | 19 | 12.18% |
| Tiger Yang | 406 | 2.26% | 5 | 3.21% |
| Tao Ma | 334 | 1.86% | 4 | 2.56% |
| Srinivas Eeda | 272 | 1.52% | 2 | 1.28% |
| Eric Ren | 225 | 1.25% | 2 | 1.28% |
| Wengang Wang | 175 | 0.98% | 3 | 1.92% |
| Larry Chen | 156 | 0.87% | 1 | 0.64% |
| Jiufei (Joyce) Xue | 88 | 0.49% | 1 | 0.64% |
| David Teigland | 83 | 0.46% | 1 | 0.64% |
| Junxiao Bi | 67 | 0.37% | 2 | 1.28% |
| Jeff Layton | 56 | 0.31% | 2 | 1.28% |
| Al Viro | 45 | 0.25% | 3 | 1.92% |
| alex chen | 39 | 0.22% | 2 | 1.28% |
| Goldwyn Rodrigues | 37 | 0.21% | 4 | 2.56% |
| Herbert Pötzl | 30 | 0.17% | 1 | 0.64% |
| Tariq Saeed | 24 | 0.13% | 1 | 0.64% |
| Pavel Machek | 23 | 0.13% | 1 | 0.64% |
| Rob Jones | 15 | 0.08% | 1 | 0.64% |
| Eric W. Biedermann | 14 | 0.08% | 1 | 0.64% |
| Christophe Jaillet | 14 | 0.08% | 1 | 0.64% |
| Arnd Bergmann | 13 | 0.07% | 1 | 0.64% |
| Joseph Qi | 10 | 0.06% | 2 | 1.28% |
| Adrian Bunk | 10 | 0.06% | 4 | 2.56% |
| Jun Piao | 8 | 0.04% | 1 | 0.64% |
| Jensen | 8 | 0.04% | 1 | 0.64% |
| Heming Zhao via Ocfs2-devel | 8 | 0.04% | 1 | 0.64% |
| Ingo Molnar | 8 | 0.04% | 3 | 1.92% |
| Christoph Hellwig | 6 | 0.03% | 1 | 0.64% |
| zhong jiang | 5 | 0.03% | 1 | 0.64% |
| Andreas Gruenbacher | 5 | 0.03% | 1 | 0.64% |
| Miklos Szeredi | 4 | 0.02% | 1 | 0.64% |
| Wolfram Sang | 4 | 0.02% | 1 | 0.64% |
| Roel Kluin | 3 | 0.02% | 2 | 1.28% |
| Coly Li | 2 | 0.01% | 1 | 0.64% |
| Andrew Morton | 2 | 0.01% | 1 | 0.64% |
| Randy Dunlap | 2 | 0.01% | 1 | 0.64% |
| Arjan van de Ven | 1 | 0.01% | 1 | 0.64% |
| Masahiro Yamada | 1 | 0.01% | 1 | 0.64% |
| Daniel Mack | 1 | 0.01% | 1 | 0.64% |
| Hariprasad Kelam | 1 | 0.01% | 1 | 0.64% |
| André Goddard Rosa | 1 | 0.01% | 1 | 0.64% |
| Alex Shi | 1 | 0.01% | 1 | 0.64% |
| Yongzhen Zhang | 1 | 0.01% | 1 | 0.64% |
| Thomas Gleixner | 1 | 0.01% | 1 | 0.64% |
| Greg Kroah-Hartman | 1 | 0.01% | 1 | 0.64% |
| Jan Engelhardt | 1 | 0.01% | 1 | 0.64% |
| Colin Ian King | 1 | 0.01% | 1 | 0.64% |
| Theodore Y. Ts'o | 1 | 0.01% | 1 | 0.64% |
| Total | 17937 | 156 |
// SPDX-License-Identifier: GPL-2.0-or-later /* * dlmglue.c * * Code which implements an OCFS2 specific interface to our DLM. * * Copyright (C) 2003, 2004 Oracle. All rights reserved. */ #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/delay.h> #include <linux/quotaops.h> #include <linux/sched/signal.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 "acl.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 */ #ifdef CONFIG_DEBUG_LOCK_ALLOC static struct lock_class_key lockdep_keys[OCFS2_NUM_LOCK_TYPES]; #endif 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 const struct ocfs2_lock_res_ops ocfs2_inode_rw_lops = { .get_osb = ocfs2_get_inode_osb, .flags = 0, }; static const 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 const struct ocfs2_lock_res_ops ocfs2_super_lops = { .flags = LOCK_TYPE_REQUIRES_REFRESH, }; static const struct ocfs2_lock_res_ops ocfs2_rename_lops = { .flags = 0, }; static const struct ocfs2_lock_res_ops ocfs2_nfs_sync_lops = { .flags = 0, }; static const struct ocfs2_lock_res_ops ocfs2_trim_fs_lops = { .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB, }; static const struct ocfs2_lock_res_ops ocfs2_orphan_scan_lops = { .flags = LOCK_TYPE_REQUIRES_REFRESH|LOCK_TYPE_USES_LVB, }; static const 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 const struct ocfs2_lock_res_ops ocfs2_inode_open_lops = { .get_osb = ocfs2_get_inode_osb, .flags = 0, }; static const struct ocfs2_lock_res_ops ocfs2_flock_lops = { .get_osb = ocfs2_get_file_osb, .flags = 0, }; static const 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 const 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; res->l_lock_wait = 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++; stats->ls_last = ktime_to_us(ktime_get_real()); } static inline void ocfs2_track_lock_refresh(struct ocfs2_lock_res *lockres) { lockres->l_lock_refresh++; } static inline void ocfs2_track_lock_wait(struct ocfs2_lock_res *lockres) { struct ocfs2_mask_waiter *mw; if (list_empty(&lockres->l_mask_waiters)) { lockres->l_lock_wait = 0; return; } mw = list_first_entry(&lockres->l_mask_waiters, struct ocfs2_mask_waiter, mw_item); lockres->l_lock_wait = ktime_to_us(ktime_mono_to_real(mw->mw_lock_start)); } 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_track_lock_wait(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, const 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); INIT_LIST_HEAD(&res->l_holders); } void ocfs2_inode_lock_res_init(struct ocfs2_lock_res *res, enum ocfs2_lock_type type, unsigned int generation, struct inode *inode) { const 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_nfs_sync_lock_init(struct ocfs2_super *osb) { ocfs2_nfs_sync_lock_res_init(&osb->osb_nfs_sync_lockres, osb); init_rwsem(&osb->nfs_sync_rwlock); } void ocfs2_trim_fs_lock_res_init(struct ocfs2_super *osb) { struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; /* Only one trimfs thread are allowed to work at the same time. */ mutex_lock(&osb->obs_trim_fs_mutex); ocfs2_lock_res_init_once(lockres); ocfs2_build_lock_name(OCFS2_LOCK_TYPE_TRIM_FS, 0, 0, lockres->l_name); ocfs2_lock_res_init_common(osb, lockres, OCFS2_LOCK_TYPE_TRIM_FS, &ocfs2_trim_fs_lops, osb); } void ocfs2_trim_fs_lock_res_uninit(struct ocfs2_super *osb) { struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; ocfs2_simple_drop_lockres(osb, lockres); ocfs2_lock_res_free(lockres); mutex_unlock(&osb->obs_trim_fs_mutex); } 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; } /* * Keep a list of processes who have interest in a lockres. * Note: this is now only uesed for check recursive cluster locking. */ static inline void ocfs2_add_holder(struct ocfs2_lock_res *lockres, struct ocfs2_lock_holder *oh) { INIT_LIST_HEAD(&oh->oh_list); oh->oh_owner_pid = get_pid(task_pid(current)); spin_lock(&lockres->l_lock); list_add_tail(&oh->oh_list, &lockres->l_holders); spin_unlock(&lockres->l_lock); } static struct ocfs2_lock_holder * ocfs2_pid_holder(struct ocfs2_lock_res *lockres, struct pid *pid) { struct ocfs2_lock_holder *oh; spin_lock(&lockres->l_lock); list_for_each_entry(oh, &lockres->l_holders, oh_list) { if (oh->oh_owner_pid == pid) { spin_unlock(&lockres->l_lock); return oh; } } spin_unlock(&lockres->l_lock); return NULL; } static inline void ocfs2_remove_holder(struct ocfs2_lock_res *lockres, struct ocfs2_lock_holder *oh) { spin_lock(&lockres->l_lock); list_del(&oh->oh_list); spin_unlock(&lockres->l_lock); put_pid(oh->oh_owner_pid); } 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); ocfs2_track_lock_wait(lockres); } } static void lockres_or_flags(struct ocfs2_lock_res *lockres, unsigned long or) { lockres_set_flags(lockres, lockres->l_flags | or); } static void lockres_clear_flags(struct ocfs2_lock_res *lockres, unsigned long clear) { lockres_set_flags(lockres, lockres->l_flags & ~clear); } static inline void ocfs2_generic_handle_downconvert_action(struct ocfs2_lock_res *lockres) { BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); BUG_ON(lockres->l_blocking <= DLM_LOCK_NL); lockres->l_level = lockres->l_requested; if (lockres->l_level <= ocfs2_highest_compat_lock_level(lockres->l_blocking)) { lockres->l_blocking = DLM_LOCK_NL; lockres_clear_flags(lockres, OCFS2_LOCK_BLOCKED); } lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); } static inline void ocfs2_generic_handle_convert_action(struct ocfs2_lock_res *lockres) { BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); BUG_ON(!(lockres->l_flags & OCFS2_LOCK_ATTACHED)); /* Convert from RO to EX doesn't really need anything as our * information is already up to data. Convert from NL to * *anything* however should mark ourselves as needing an * update */ if (lockres->l_level == DLM_LOCK_NL && lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); lockres->l_level = lockres->l_requested; /* * We set the OCFS2_LOCK_UPCONVERT_FINISHING flag before clearing * the OCFS2_LOCK_BUSY flag to prevent the dc thread from * downconverting the lock before the upconvert has fully completed. * Do not prevent the dc thread from downconverting if NONBLOCK lock * had already returned. */ if (!(lockres->l_flags & OCFS2_LOCK_NONBLOCK_FINISHED)) lockres_or_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); else lockres_clear_flags(lockres, OCFS2_LOCK_NONBLOCK_FINISHED); lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); } static inline void ocfs2_generic_handle_attach_action(struct ocfs2_lock_res *lockres) { BUG_ON((!(lockres->l_flags & OCFS2_LOCK_BUSY))); BUG_ON(lockres->l_flags & OCFS2_LOCK_ATTACHED); if (lockres->l_requested > DLM_LOCK_NL && !(lockres->l_flags & OCFS2_LOCK_LOCAL) && lockres->l_ops->flags & LOCK_TYPE_REQUIRES_REFRESH) lockres_or_flags(lockres, OCFS2_LOCK_NEEDS_REFRESH); lockres->l_level = lockres->l_requested; lockres_or_flags(lockres, OCFS2_LOCK_ATTACHED); lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); } static int ocfs2_generic_handle_bast(struct ocfs2_lock_res *lockres, int level) { int needs_downconvert = 0; assert_spin_locked(&lockres->l_lock); if (level > lockres->l_blocking) { /* only schedule a downconvert if we haven't already scheduled * one that goes low enough to satisfy the level we're * blocking. this also catches the case where we get * duplicate BASTs */ if (ocfs2_highest_compat_lock_level(level) < ocfs2_highest_compat_lock_level(lockres->l_blocking)) needs_downconvert = 1; lockres->l_blocking = level; } mlog(ML_BASTS, "lockres %s, block %d, level %d, l_block %d, dwn %d\n", lockres->l_name, level, lockres->l_level, lockres->l_blocking, needs_downconvert); if (needs_downconvert) lockres_or_flags(lockres, OCFS2_LOCK_BLOCKED); mlog(0, "needs_downconvert = %d\n", needs_downconvert); return needs_downconvert; } /* * OCFS2_LOCK_PENDING and l_pending_gen. * * Why does OCFS2_LOCK_PENDING exist? To close a race between setting * OCFS2_LOCK_BUSY and calling ocfs2_dlm_lock(). See ocfs2_unblock_lock() * for more details on the race. * * OCFS2_LOCK_PENDING closes the race quite nicely. However, it introduces * a race on itself. In o2dlm, we can get the ast before ocfs2_dlm_lock() * returns. The ast clears OCFS2_LOCK_BUSY, and must therefore clear * OCFS2_LOCK_PENDING at the same time. When ocfs2_dlm_lock() returns, * the caller is going to try to clear PENDING again. If nothing else is * happening, __lockres_clear_pending() sees PENDING is unset and does * nothing. * * But what if another path (eg downconvert thread) has just started a * new locking action? The other path has re-set PENDING. Our path * cannot clear PENDING, because that will re-open the original race * window. * * [Example] * * ocfs2_meta_lock() * ocfs2_cluster_lock() * set BUSY * set PENDING * drop l_lock * ocfs2_dlm_lock() * ocfs2_locking_ast() ocfs2_downconvert_thread() * clear PENDING ocfs2_unblock_lock() * take_l_lock * !BUSY * ocfs2_prepare_downconvert() * set BUSY * set PENDING * drop l_lock * take l_lock * clear PENDING * drop l_lock * <window> * ocfs2_dlm_lock() * * So as you can see, we now have a window where l_lock is not held, * PENDING is not set, and ocfs2_dlm_lock() has not been called. * * The core problem is that ocfs2_cluster_lock() has cleared the PENDING * set by ocfs2_prepare_downconvert(). That wasn't nice. * * To solve this we introduce l_pending_gen. A call to * lockres_clear_pending() will only do so when it is passed a generation * number that matches the lockres. lockres_set_pending() will return the * current generation number. When ocfs2_cluster_lock() goes to clear * PENDING, it passes the generation it got from set_pending(). In our * example above, the generation numbers will *not* match. Thus, * ocfs2_cluster_lock() will not clear the PENDING set by * ocfs2_prepare_downconvert(). */ /* Unlocked version for ocfs2_locking_ast() */ static void __lockres_clear_pending(struct ocfs2_lock_res *lockres, unsigned int generation, struct ocfs2_super *osb) { assert_spin_locked(&lockres->l_lock); /* * The ast and locking functions can race us here. The winner * will clear pending, the loser will not. */ if (!(lockres->l_flags & OCFS2_LOCK_PENDING) || (lockres->l_pending_gen != generation)) return; lockres_clear_flags(lockres, OCFS2_LOCK_PENDING); lockres->l_pending_gen++; /* * The downconvert thread may have skipped us because we * were PENDING. Wake it up. */ if (lockres->l_flags & OCFS2_LOCK_BLOCKED) ocfs2_wake_downconvert_thread(osb); } /* Locked version for callers of ocfs2_dlm_lock() */ static void lockres_clear_pending(struct ocfs2_lock_res *lockres, unsigned int generation, struct ocfs2_super *osb) { unsigned long flags; spin_lock_irqsave(&lockres->l_lock, flags); __lockres_clear_pending(lockres, generation, osb); spin_unlock_irqrestore(&lockres->l_lock, flags); } static unsigned int lockres_set_pending(struct ocfs2_lock_res *lockres) { assert_spin_locked(&lockres->l_lock); BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BUSY)); lockres_or_flags(lockres, OCFS2_LOCK_PENDING); return lockres->l_pending_gen; } static void ocfs2_blocking_ast(struct ocfs2_dlm_lksb *lksb, int level) { struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); int needs_downconvert; unsigned long flags; BUG_ON(level <= DLM_LOCK_NL); mlog(ML_BASTS, "BAST fired for lockres %s, blocking %d, level %d, " "type %s\n", lockres->l_name, level, lockres->l_level, ocfs2_lock_type_string(lockres->l_type)); /* * We can skip the bast for locks which don't enable caching - * they'll be dropped at the earliest possible time anyway. */ if (lockres->l_flags & OCFS2_LOCK_NOCACHE) return; spin_lock_irqsave(&lockres->l_lock, flags); needs_downconvert = ocfs2_generic_handle_bast(lockres, level); if (needs_downconvert) ocfs2_schedule_blocked_lock(osb, lockres); spin_unlock_irqrestore(&lockres->l_lock, flags); wake_up(&lockres->l_event); ocfs2_wake_downconvert_thread(osb); } static void ocfs2_locking_ast(struct ocfs2_dlm_lksb *lksb) { struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); struct ocfs2_super *osb = ocfs2_get_lockres_osb(lockres); unsigned long flags; int status; spin_lock_irqsave(&lockres->l_lock, flags); status = ocfs2_dlm_lock_status(&lockres->l_lksb); if (status == -EAGAIN) { lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); goto out; } if (status) { mlog(ML_ERROR, "lockres %s: lksb status value of %d!\n", lockres->l_name, status); spin_unlock_irqrestore(&lockres->l_lock, flags); return; } mlog(ML_BASTS, "AST fired for lockres %s, action %d, unlock %d, " "level %d => %d\n", lockres->l_name, lockres->l_action, lockres->l_unlock_action, lockres->l_level, lockres->l_requested); switch(lockres->l_action) { case OCFS2_AST_ATTACH: ocfs2_generic_handle_attach_action(lockres); lockres_clear_flags(lockres, OCFS2_LOCK_LOCAL); break; case OCFS2_AST_CONVERT: ocfs2_generic_handle_convert_action(lockres); break; case OCFS2_AST_DOWNCONVERT: ocfs2_generic_handle_downconvert_action(lockres); break; default: mlog(ML_ERROR, "lockres %s: AST fired with invalid action: %u, " "flags 0x%lx, unlock: %u\n", lockres->l_name, lockres->l_action, lockres->l_flags, lockres->l_unlock_action); BUG(); } out: /* set it to something invalid so if we get called again we * can catch it. */ lockres->l_action = OCFS2_AST_INVALID; /* Did we try to cancel this lock? Clear that state */ if (lockres->l_unlock_action == OCFS2_UNLOCK_CANCEL_CONVERT) lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; /* * We may have beaten the locking functions here. We certainly * know that dlm_lock() has been called :-) * Because we can't have two lock calls in flight at once, we * can use lockres->l_pending_gen. */ __lockres_clear_pending(lockres, lockres->l_pending_gen, osb); wake_up(&lockres->l_event); spin_unlock_irqrestore(&lockres->l_lock, flags); } static void ocfs2_unlock_ast(struct ocfs2_dlm_lksb *lksb, int error) { struct ocfs2_lock_res *lockres = ocfs2_lksb_to_lock_res(lksb); unsigned long flags; mlog(ML_BASTS, "UNLOCK AST fired for lockres %s, action = %d\n", lockres->l_name, lockres->l_unlock_action); spin_lock_irqsave(&lockres->l_lock, flags); if (error) { mlog(ML_ERROR, "Dlm passes error %d for lock %s, " "unlock_action %d\n", error, lockres->l_name, lockres->l_unlock_action); spin_unlock_irqrestore(&lockres->l_lock, flags); return; } switch(lockres->l_unlock_action) { case OCFS2_UNLOCK_CANCEL_CONVERT: mlog(0, "Cancel convert success for %s\n", lockres->l_name); lockres->l_action = OCFS2_AST_INVALID; /* Downconvert thread may have requeued this lock, we * need to wake it. */ if (lockres->l_flags & OCFS2_LOCK_BLOCKED) ocfs2_wake_downconvert_thread(ocfs2_get_lockres_osb(lockres)); break; case OCFS2_UNLOCK_DROP_LOCK: lockres->l_level = DLM_LOCK_IV; break; default: BUG(); } lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; wake_up(&lockres->l_event); spin_unlock_irqrestore(&lockres->l_lock, flags); } /* * This is the filesystem locking protocol. It provides the lock handling * hooks for the underlying DLM. It has a maximum version number. * The version number allows interoperability with systems running at * the same major number and an equal or smaller minor number. * * Whenever the filesystem does new things with locks (adds or removes a * lock, orders them differently, does different things underneath a lock), * the version must be changed. The protocol is negotiated when joining * the dlm domain. A node may join the domain if its major version is * identical to all other nodes and its minor version is greater than * or equal to all other nodes. When its minor version is greater than * the other nodes, it will run at the minor version specified by the * other nodes. * * If a locking change is made that will not be compatible with older * versions, the major number must be increased and the minor version set * to zero. If a change merely adds a behavior that can be disabled when * speaking to older versions, the minor version must be increased. If a * change adds a fully backwards compatible change (eg, LVB changes that * are just ignored by older versions), the version does not need to be * updated. */ static struct ocfs2_locking_protocol lproto = { .lp_max_version = { .pv_major = OCFS2_LOCKING_PROTOCOL_MAJOR, .pv_minor = OCFS2_LOCKING_PROTOCOL_MINOR, }, .lp_lock_ast = ocfs2_locking_ast, .lp_blocking_ast = ocfs2_blocking_ast, .lp_unlock_ast = ocfs2_unlock_ast, }; void ocfs2_set_locking_protocol(void) { ocfs2_stack_glue_set_max_proto_version(&lproto.lp_max_version); } static inline void ocfs2_recover_from_dlm_error(struct ocfs2_lock_res *lockres, int convert) { unsigned long flags; spin_lock_irqsave(&lockres->l_lock, flags); lockres_clear_flags(lockres, OCFS2_LOCK_BUSY); lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); if (convert) lockres->l_action = OCFS2_AST_INVALID; else lockres->l_unlock_action = OCFS2_UNLOCK_INVALID; spin_unlock_irqrestore(&lockres->l_lock, flags); wake_up(&lockres->l_event); } /* Note: If we detect another process working on the lock (i.e., * OCFS2_LOCK_BUSY), we'll bail out returning 0. It's up to the caller * to do the right thing in that case. */ static int ocfs2_lock_create(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres, int level, u32 dlm_flags) { int ret = 0; unsigned long flags; unsigned int gen; mlog(0, "lock %s, level = %d, flags = %u\n", lockres->l_name, level, dlm_flags); spin_lock_irqsave(&lockres->l_lock, flags); if ((lockres->l_flags & OCFS2_LOCK_ATTACHED) || (lockres->l_flags & OCFS2_LOCK_BUSY)) { spin_unlock_irqrestore(&lockres->l_lock, flags); goto bail; } lockres->l_action = OCFS2_AST_ATTACH; lockres->l_requested = level; lockres_or_flags(lockres, OCFS2_LOCK_BUSY); gen = lockres_set_pending(lockres); spin_unlock_irqrestore(&lockres->l_lock, flags); ret = ocfs2_dlm_lock(osb->cconn, level, &lockres->l_lksb, dlm_flags, lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1); lockres_clear_pending(lockres, gen, osb); if (ret) { ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres); ocfs2_recover_from_dlm_error(lockres, 1); } mlog(0, "lock %s, return from ocfs2_dlm_lock\n", lockres->l_name); bail: return ret; } static inline int ocfs2_check_wait_flag(struct ocfs2_lock_res *lockres, int flag) { unsigned long flags; int ret; spin_lock_irqsave(&lockres->l_lock, flags); ret = lockres->l_flags & flag; spin_unlock_irqrestore(&lockres->l_lock, flags); return ret; } static inline void ocfs2_wait_on_busy_lock(struct ocfs2_lock_res *lockres) { wait_event(lockres->l_event, !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_BUSY)); } static inline void ocfs2_wait_on_refreshing_lock(struct ocfs2_lock_res *lockres) { wait_event(lockres->l_event, !ocfs2_check_wait_flag(lockres, OCFS2_LOCK_REFRESHING)); } /* predict what lock level we'll be dropping down to on behalf * of another node, and return true if the currently wanted * level will be compatible with it. */ static inline int ocfs2_may_continue_on_blocked_lock(struct ocfs2_lock_res *lockres, int wanted) { BUG_ON(!(lockres->l_flags & OCFS2_LOCK_BLOCKED)); return wanted <= ocfs2_highest_compat_lock_level(lockres->l_blocking); } static void ocfs2_init_mask_waiter(struct ocfs2_mask_waiter *mw) { INIT_LIST_HEAD(&mw->mw_item); init_completion(&mw->mw_complete); ocfs2_init_start_time(mw); } static int ocfs2_wait_for_mask(struct ocfs2_mask_waiter *mw) { wait_for_completion(&mw->mw_complete); /* Re-arm the completion in case we want to wait on it again */ reinit_completion(&mw->mw_complete); return mw->mw_status; } static void lockres_add_mask_waiter(struct ocfs2_lock_res *lockres, struct ocfs2_mask_waiter *mw, unsigned long mask, unsigned long goal) { BUG_ON(!list_empty(&mw->mw_item)); assert_spin_locked(&lockres->l_lock); list_add_tail(&mw->mw_item, &lockres->l_mask_waiters); mw->mw_mask = mask; mw->mw_goal = goal; ocfs2_track_lock_wait(lockres); } /* returns 0 if the mw that was removed was already satisfied, -EBUSY * if the mask still hadn't reached its goal */ static int __lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres, struct ocfs2_mask_waiter *mw) { int ret = 0; assert_spin_locked(&lockres->l_lock); if (!list_empty(&mw->mw_item)) { if ((lockres->l_flags & mw->mw_mask) != mw->mw_goal) ret = -EBUSY; list_del_init(&mw->mw_item); init_completion(&mw->mw_complete); ocfs2_track_lock_wait(lockres); } return ret; } static int lockres_remove_mask_waiter(struct ocfs2_lock_res *lockres, struct ocfs2_mask_waiter *mw) { unsigned long flags; int ret = 0; spin_lock_irqsave(&lockres->l_lock, flags); ret = __lockres_remove_mask_waiter(lockres, mw); spin_unlock_irqrestore(&lockres->l_lock, flags); return ret; } static int ocfs2_wait_for_mask_interruptible(struct ocfs2_mask_waiter *mw, struct ocfs2_lock_res *lockres) { int ret; ret = wait_for_completion_interruptible(&mw->mw_complete); if (ret) lockres_remove_mask_waiter(lockres, mw); else ret = mw->mw_status; /* Re-arm the completion in case we want to wait on it again */ reinit_completion(&mw->mw_complete); return ret; } static int __ocfs2_cluster_lock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres, int level, u32 lkm_flags, int arg_flags, int l_subclass, unsigned long caller_ip) { struct ocfs2_mask_waiter mw; int wait, catch_signals = !(osb->s_mount_opt & OCFS2_MOUNT_NOINTR); int ret = 0; /* gcc doesn't realize wait = 1 guarantees ret is set */ unsigned long flags; unsigned int gen; int noqueue_attempted = 0; int dlm_locked = 0; int kick_dc = 0; if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) { mlog_errno(-EINVAL); return -EINVAL; } ocfs2_init_mask_waiter(&mw); if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) lkm_flags |= DLM_LKF_VALBLK; again: wait = 0; spin_lock_irqsave(&lockres->l_lock, flags); if (catch_signals && signal_pending(current)) { ret = -ERESTARTSYS; goto unlock; } mlog_bug_on_msg(lockres->l_flags & OCFS2_LOCK_FREEING, "Cluster lock called on freeing lockres %s! flags " "0x%lx\n", lockres->l_name, lockres->l_flags); /* We only compare against the currently granted level * here. If the lock is blocked waiting on a downconvert, * we'll get caught below. */ if (lockres->l_flags & OCFS2_LOCK_BUSY && level > lockres->l_level) { /* is someone sitting in dlm_lock? If so, wait on * them. */ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BUSY, 0); wait = 1; goto unlock; } if (lockres->l_flags & OCFS2_LOCK_UPCONVERT_FINISHING) { /* * We've upconverted. If the lock now has a level we can * work with, we take it. If, however, the lock is not at the * required level, we go thru the full cycle. One way this could * happen is if a process requesting an upconvert to PR is * closely followed by another requesting upconvert to an EX. * If the process requesting EX lands here, we want it to * continue attempting to upconvert and let the process * requesting PR take the lock. * If multiple processes request upconvert to PR, the first one * here will take the lock. The others will have to go thru the * OCFS2_LOCK_BLOCKED check to ensure that there is no pending * downconvert request. */ if (level <= lockres->l_level) goto update_holders; } if (lockres->l_flags & OCFS2_LOCK_BLOCKED && !ocfs2_may_continue_on_blocked_lock(lockres, level)) { /* is the lock is currently blocked on behalf of * another node */ lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_BLOCKED, 0); wait = 1; goto unlock; } if (level > lockres->l_level) { if (noqueue_attempted > 0) { ret = -EAGAIN; goto unlock; } if (lkm_flags & DLM_LKF_NOQUEUE) noqueue_attempted = 1; if (lockres->l_action != OCFS2_AST_INVALID) mlog(ML_ERROR, "lockres %s has action %u pending\n", lockres->l_name, lockres->l_action); if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { lockres->l_action = OCFS2_AST_ATTACH; lkm_flags &= ~DLM_LKF_CONVERT; } else { lockres->l_action = OCFS2_AST_CONVERT; lkm_flags |= DLM_LKF_CONVERT; } lockres->l_requested = level; lockres_or_flags(lockres, OCFS2_LOCK_BUSY); gen = lockres_set_pending(lockres); spin_unlock_irqrestore(&lockres->l_lock, flags); BUG_ON(level == DLM_LOCK_IV); BUG_ON(level == DLM_LOCK_NL); mlog(ML_BASTS, "lockres %s, convert from %d to %d\n", lockres->l_name, lockres->l_level, level); /* call dlm_lock to upgrade lock now */ ret = ocfs2_dlm_lock(osb->cconn, level, &lockres->l_lksb, lkm_flags, lockres->l_name, OCFS2_LOCK_ID_MAX_LEN - 1); lockres_clear_pending(lockres, gen, osb); if (ret) { if (!(lkm_flags & DLM_LKF_NOQUEUE) || (ret != -EAGAIN)) { ocfs2_log_dlm_error("ocfs2_dlm_lock", ret, lockres); } ocfs2_recover_from_dlm_error(lockres, 1); goto out; } dlm_locked = 1; mlog(0, "lock %s, successful return from ocfs2_dlm_lock\n", lockres->l_name); /* At this point we've gone inside the dlm and need to * complete our work regardless. */ catch_signals = 0; /* wait for busy to clear and carry on */ goto again; } update_holders: /* Ok, if we get here then we're good to go. */ ocfs2_inc_holders(lockres, level); ret = 0; unlock: lockres_clear_flags(lockres, OCFS2_LOCK_UPCONVERT_FINISHING); /* ocfs2_unblock_lock request on seeing OCFS2_LOCK_UPCONVERT_FINISHING */ kick_dc = (lockres->l_flags & OCFS2_LOCK_BLOCKED); spin_unlock_irqrestore(&lockres->l_lock, flags); if (kick_dc) ocfs2_wake_downconvert_thread(osb); out: /* * This is helping work around a lock inversion between the page lock * and dlm locks. One path holds the page lock while calling aops * which block acquiring dlm locks. The voting thread holds dlm * locks while acquiring page locks while down converting data locks. * This block is helping an aop path notice the inversion and back * off to unlock its page lock before trying the dlm lock again. */ if (wait && arg_flags & OCFS2_LOCK_NONBLOCK && mw.mw_mask & (OCFS2_LOCK_BUSY|OCFS2_LOCK_BLOCKED)) { wait = 0; spin_lock_irqsave(&lockres->l_lock, flags); if (__lockres_remove_mask_waiter(lockres, &mw)) { if (dlm_locked) lockres_or_flags(lockres, OCFS2_LOCK_NONBLOCK_FINISHED); spin_unlock_irqrestore(&lockres->l_lock, flags); ret = -EAGAIN; } else { spin_unlock_irqrestore(&lockres->l_lock, flags); goto again; } } if (wait) { ret = ocfs2_wait_for_mask(&mw); if (ret == 0) goto again; mlog_errno(ret); } ocfs2_update_lock_stats(lockres, level, &mw, ret); #ifdef CONFIG_DEBUG_LOCK_ALLOC if (!ret && lockres->l_lockdep_map.key != NULL) { if (level == DLM_LOCK_PR) rwsem_acquire_read(&lockres->l_lockdep_map, l_subclass, !!(arg_flags & OCFS2_META_LOCK_NOQUEUE), caller_ip); else rwsem_acquire(&lockres->l_lockdep_map, l_subclass, !!(arg_flags & OCFS2_META_LOCK_NOQUEUE), caller_ip); } #endif return ret; } static inline int ocfs2_cluster_lock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres, int level, u32 lkm_flags, int arg_flags) { return __ocfs2_cluster_lock(osb, lockres, level, lkm_flags, arg_flags, 0, _RET_IP_); } static void __ocfs2_cluster_unlock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres, int level, unsigned long caller_ip) { unsigned long flags; spin_lock_irqsave(&lockres->l_lock, flags); ocfs2_dec_holders(lockres, level); ocfs2_downconvert_on_unlock(osb, lockres); spin_unlock_irqrestore(&lockres->l_lock, flags); #ifdef CONFIG_DEBUG_LOCK_ALLOC if (lockres->l_lockdep_map.key != NULL) rwsem_release(&lockres->l_lockdep_map, 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(!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); 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); 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(osb, lockres, level, 0, 0); if (status < 0) mlog_errno(status); return status; } int ocfs2_try_rw_lock(struct inode *inode, int write) { int status, level; struct ocfs2_lock_res *lockres; struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); mlog(0, "inode %llu try to 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(osb, lockres, level, DLM_LKF_NOQUEUE, 0); 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(osb, 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); 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(osb, 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); 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(osb, 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(osb, lockres, DLM_LOCK_PR); if(lockres->l_ex_holders) ocfs2_cluster_unlock(osb, 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 - OCFS2_SEC_BITS) #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 timespec64 *spec) { u64 res; u64 sec = clamp_t(time64_t, spec->tv_sec, 0, 0x3ffffffffull); 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; struct timespec64 ts; lvb = ocfs2_dlm_lvb(&lockres->l_lksb); /* * Invalidate the LVB of a deleted inode - this way other * nodes are forced to go to disk and discover the new inode * status. */ if (oi->ip_flags & OCFS2_INODE_DELETED) { lvb->lvb_version = 0; goto out; } lvb->lvb_version = OCFS2_LVB_VERSION; lvb->lvb_isize = cpu_to_be64(i_size_read(inode)); lvb->lvb_iclusters = cpu_to_be32(oi->ip_clusters); lvb->lvb_iuid = cpu_to_be32(i_uid_read(inode)); lvb->lvb_igid = cpu_to_be32(i_gid_read(inode)); lvb->lvb_imode = cpu_to_be16(inode->i_mode); lvb->lvb_inlink = cpu_to_be16(inode->i_nlink); ts = inode_get_atime(inode); lvb->lvb_iatime_packed = cpu_to_be64(ocfs2_pack_timespec(&ts)); ts = inode_get_ctime(inode); lvb->lvb_ictime_packed = cpu_to_be64(ocfs2_pack_timespec(&ts)); ts = inode_get_mtime(inode); lvb->lvb_imtime_packed = cpu_to_be64(ocfs2_pack_timespec(&ts)); 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 timespec64 *spec, u64 packed_time) { spec->tv_sec = packed_time >> OCFS2_SEC_SHIFT; spec->tv_nsec = packed_time & OCFS2_NSEC_MASK; } static int 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; struct timespec64 ts; mlog_meta_lvb(0, lockres); lvb = ocfs2_dlm_lvb(&lockres->l_lksb); if (inode_wrong_type(inode, be16_to_cpu(lvb->lvb_imode))) return -ESTALE; /* We're safe here without the lockres lock... */ spin_lock(&oi->ip_lock); oi->ip_clusters = be32_to_cpu(lvb->lvb_iclusters); i_size_write(inode, be64_to_cpu(lvb->lvb_isize)); oi->ip_attr = be32_to_cpu(lvb->lvb_iattr); oi->ip_dyn_features = be16_to_cpu(lvb->lvb_idynfeatures); ocfs2_set_inode_flags(inode); /* fast-symlinks are a special case */ if (S_ISLNK(inode->i_mode) && !oi->ip_clusters) inode->i_blocks = 0; else inode->i_blocks = ocfs2_inode_sector_count(inode); i_uid_write(inode, be32_to_cpu(lvb->lvb_iuid)); i_gid_write(inode, be32_to_cpu(lvb->lvb_igid)); inode->i_mode = be16_to_cpu(lvb->lvb_imode); set_nlink(inode, be16_to_cpu(lvb->lvb_inlink)); ocfs2_unpack_timespec(&ts, be64_to_cpu(lvb->lvb_iatime_packed)); inode_set_atime_to_ts(inode, ts); ocfs2_unpack_timespec(&ts, be64_to_cpu(lvb->lvb_imtime_packed)); inode_set_mtime_to_ts(inode, ts); ocfs2_unpack_timespec(&ts, be64_to_cpu(lvb->lvb_ictime_packed)); inode_set_ctime_to_ts(inode, ts); spin_unlock(&oi->ip_lock); return 0; } 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); status = ocfs2_refresh_inode_from_lvb(inode); goto bail_refresh; } 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; if (inode_wrong_type(inode, le16_to_cpu(fe->i_mode))) { status = -ESTALE; goto bail_refresh; } /* 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; 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 ((arg_flags & OCFS2_META_LOCK_GETBH) || ocfs2_mount_local(osb)) goto update; if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) ocfs2_wait_for_recovery(osb); lockres = &OCFS2_I(inode)->ip_inode_lockres; level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; dlm_flags = 0; if (arg_flags & OCFS2_META_LOCK_NOQUEUE) dlm_flags |= DLM_LKF_NOQUEUE; status = __ocfs2_cluster_lock(osb, lockres, level, dlm_flags, arg_flags, subclass, _RET_IP_); if (status < 0) { if (status != -EAGAIN) mlog_errno(status); goto bail; } /* Notify the error cleanup path to drop the cluster lock. */ acquired = 1; /* We wait twice because a node may have died while we were in * the lower dlm layers. The second time though, we've * committed to owning this lock so we don't allow signals to * abort the operation. */ if (!(arg_flags & OCFS2_META_LOCK_RECOVERY)) ocfs2_wait_for_recovery(osb); update: /* * 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); } 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. */ 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 we can't get inode lock immediately, we should not return * directly here, since this will lead to a softlockup problem. * The method is to get a blocking lock and immediately unlock * before returning, this can avoid CPU resource waste due to * lots of retries, and benefits fairness in getting lock. */ 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 wait) { int ret; if (wait) ret = ocfs2_inode_lock(inode, NULL, 0); else ret = ocfs2_try_inode_lock(inode, NULL, 0); if (ret < 0) { if (ret != -EAGAIN) 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); if (wait) ret = ocfs2_inode_lock(inode, &bh, 1); else ret = ocfs2_try_inode_lock(inode, &bh, 1); if (ret < 0) { if (ret != -EAGAIN) mlog_errno(ret); return ret; } *level = 1; if (ocfs2_should_update_atime(inode, vfsmnt)) ocfs2_update_inode_atime(inode, 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(osb) && !ocfs2_mount_local(osb)) ocfs2_cluster_unlock(osb, lockres, level); } /* * This _tracker variantes are introduced to deal with the recursive cluster * locking issue. The idea is to keep track of a lock holder on the stack of * the current process. If there's a lock holder on the stack, we know the * task context is already protected by cluster locking. Currently, they're * used in some VFS entry routines. * * return < 0 on error, return == 0 if there's no lock holder on the stack * before this call, return == 1 if this call would be a recursive locking. * return == -1 if this lock attempt will cause an upgrade which is forbidden. * * When taking lock levels into account,we face some different situations. * * 1. no lock is held * In this case, just lock the inode as requested and return 0 * * 2. We are holding a lock * For this situation, things diverges into several cases * * wanted holding what to do * ex ex see 2.1 below * ex pr see 2.2 below * pr ex see 2.1 below * pr pr see 2.1 below * * 2.1 lock level that is been held is compatible * with the wanted level, so no lock action will be tacken. * * 2.2 Otherwise, an upgrade is needed, but it is forbidden. * * Reason why upgrade within a process is forbidden is that * lock upgrade may cause dead lock. The following illustrates * how it happens. * * thread on node1 thread on node2 * ocfs2_inode_lock_tracker(ex=0) * * <====== ocfs2_inode_lock_tracker(ex=1) * * ocfs2_inode_lock_tracker(ex=1) */ int ocfs2_inode_lock_tracker(struct inode *inode, struct buffer_head **ret_bh, int ex, struct ocfs2_lock_holder *oh) { int status = 0; struct ocfs2_lock_res *lockres; struct ocfs2_lock_holder *tmp_oh; struct pid *pid = task_pid(current); lockres = &OCFS2_I(inode)->ip_inode_lockres; tmp_oh = ocfs2_pid_holder(lockres, pid); if (!tmp_oh) { /* * This corresponds to the case 1. * We haven't got any lock before. */ status = ocfs2_inode_lock_full(inode, ret_bh, ex, 0); if (status < 0) { if (status != -ENOENT) mlog_errno(status); return status; } oh->oh_ex = ex; ocfs2_add_holder(lockres, oh); return 0; } if (unlikely(ex && !tmp_oh->oh_ex)) { /* * case 2.2 upgrade may cause dead lock, forbid it. */ mlog(ML_ERROR, "Recursive locking is not permitted to " "upgrade to EX level from PR level.\n"); dump_stack(); return -EINVAL; } /* * case 2.1 OCFS2_META_LOCK_GETBH flag make ocfs2_inode_lock_full. * ignore the lock level and just update it. */ if (ret_bh) { status = ocfs2_inode_lock_full(inode, ret_bh, ex, OCFS2_META_LOCK_GETBH); if (status < 0) { if (status != -ENOENT) mlog_errno(status); return status; } } return 1; } void ocfs2_inode_unlock_tracker(struct inode *inode, int ex, struct ocfs2_lock_holder *oh, int had_lock) { struct ocfs2_lock_res *lockres; lockres = &OCFS2_I(inode)->ip_inode_lockres; /* had_lock means that the currect process already takes the cluster * lock previously. * If had_lock is 1, we have nothing to do here. * If had_lock is 0, we will release the lock. */ if (!had_lock) { ocfs2_inode_unlock(inode, oh->oh_ex); ocfs2_remove_holder(lockres, oh); } } int ocfs2_orphan_scan_lock(struct ocfs2_super *osb, u32 *seqno) { struct ocfs2_lock_res *lockres; struct ocfs2_orphan_scan_lvb *lvb; int status = 0; if (ocfs2_is_hard_readonly(osb)) return -EROFS; if (ocfs2_mount_local(osb)) return 0; lockres = &osb->osb_orphan_scan.os_lockres; status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0); if (status < 0) return status; lvb = ocfs2_dlm_lvb(&lockres->l_lksb); if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) && lvb->lvb_version == OCFS2_ORPHAN_LVB_VERSION) *seqno = be32_to_cpu(lvb->lvb_os_seqno); else *seqno = osb->osb_orphan_scan.os_seqno + 1; return status; } void ocfs2_orphan_scan_unlock(struct ocfs2_super *osb, u32 seqno) { struct ocfs2_lock_res *lockres; struct ocfs2_orphan_scan_lvb *lvb; if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) { lockres = &osb->osb_orphan_scan.os_lockres; lvb = ocfs2_dlm_lvb(&lockres->l_lksb); lvb->lvb_version = OCFS2_ORPHAN_LVB_VERSION; lvb->lvb_os_seqno = cpu_to_be32(seqno); ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); } } int ocfs2_super_lock(struct ocfs2_super *osb, int ex) { int status = 0; int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; if (ocfs2_is_hard_readonly(osb)) return -EROFS; if (ocfs2_mount_local(osb)) goto bail; status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); if (status < 0) { mlog_errno(status); goto bail; } /* The super block lock path is really in the best position to * know when resources covered by the lock need to be * refreshed, so we do it here. Of course, making sense of * everything is up to the caller :) */ status = ocfs2_should_refresh_lock_res(lockres); if (status) { status = ocfs2_refresh_slot_info(osb); ocfs2_complete_lock_res_refresh(lockres, status); if (status < 0) { ocfs2_cluster_unlock(osb, lockres, level); mlog_errno(status); } ocfs2_track_lock_refresh(lockres); } bail: return status; } void ocfs2_super_unlock(struct ocfs2_super *osb, int ex) { int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; struct ocfs2_lock_res *lockres = &osb->osb_super_lockres; if (!ocfs2_mount_local(osb)) ocfs2_cluster_unlock(osb, lockres, level); } int ocfs2_rename_lock(struct ocfs2_super *osb) { int status; struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; if (ocfs2_is_hard_readonly(osb)) return -EROFS; if (ocfs2_mount_local(osb)) return 0; status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, 0, 0); if (status < 0) mlog_errno(status); return status; } void ocfs2_rename_unlock(struct ocfs2_super *osb) { struct ocfs2_lock_res *lockres = &osb->osb_rename_lockres; if (!ocfs2_mount_local(osb)) ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); } int ocfs2_nfs_sync_lock(struct ocfs2_super *osb, int ex) { int status; struct ocfs2_lock_res *lockres = &osb->osb_nfs_sync_lockres; if (ocfs2_is_hard_readonly(osb)) return -EROFS; if (ex) down_write(&osb->nfs_sync_rwlock); else down_read(&osb->nfs_sync_rwlock); 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); if (ex) up_write(&osb->nfs_sync_rwlock); else up_read(&osb->nfs_sync_rwlock); } 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); if (ex) up_write(&osb->nfs_sync_rwlock); else up_read(&osb->nfs_sync_rwlock); } int ocfs2_trim_fs_lock(struct ocfs2_super *osb, struct ocfs2_trim_fs_info *info, int trylock) { int status; struct ocfs2_trim_fs_lvb *lvb; struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; if (info) info->tf_valid = 0; if (ocfs2_is_hard_readonly(osb)) return -EROFS; if (ocfs2_mount_local(osb)) return 0; status = ocfs2_cluster_lock(osb, lockres, DLM_LOCK_EX, trylock ? DLM_LKF_NOQUEUE : 0, 0); if (status < 0) { if (status != -EAGAIN) mlog_errno(status); return status; } if (info) { lvb = ocfs2_dlm_lvb(&lockres->l_lksb); if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) && lvb->lvb_version == OCFS2_TRIMFS_LVB_VERSION) { info->tf_valid = 1; info->tf_success = lvb->lvb_success; info->tf_nodenum = be32_to_cpu(lvb->lvb_nodenum); info->tf_start = be64_to_cpu(lvb->lvb_start); info->tf_len = be64_to_cpu(lvb->lvb_len); info->tf_minlen = be64_to_cpu(lvb->lvb_minlen); info->tf_trimlen = be64_to_cpu(lvb->lvb_trimlen); } } return status; } void ocfs2_trim_fs_unlock(struct ocfs2_super *osb, struct ocfs2_trim_fs_info *info) { struct ocfs2_trim_fs_lvb *lvb; struct ocfs2_lock_res *lockres = &osb->osb_trim_fs_lockres; if (ocfs2_mount_local(osb)) return; if (info) { lvb = ocfs2_dlm_lvb(&lockres->l_lksb); lvb->lvb_version = OCFS2_TRIMFS_LVB_VERSION; lvb->lvb_success = info->tf_success; lvb->lvb_nodenum = cpu_to_be32(info->tf_nodenum); lvb->lvb_start = cpu_to_be64(info->tf_start); lvb->lvb_len = cpu_to_be64(info->tf_len); lvb->lvb_minlen = cpu_to_be64(info->tf_minlen); lvb->lvb_trimlen = cpu_to_be64(info->tf_trimlen); } ocfs2_cluster_unlock(osb, lockres, DLM_LOCK_EX); } 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_filter_secs = 0; 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) * New in version 4 * - Add last pr/ex unlock times and first lock wait time in usecs */ #define OCFS2_DLM_DEBUG_STR_VERSION 4 static int ocfs2_dlm_seq_show(struct seq_file *m, void *v) { int i; char *lvb; struct ocfs2_lock_res *lockres = v; #ifdef CONFIG_OCFS2_FS_STATS u64 now, last; struct ocfs2_dlm_debug *dlm_debug = ((struct ocfs2_dlm_seq_priv *)m->private)->p_dlm_debug; #endif if (!lockres) return -EINVAL; #ifdef CONFIG_OCFS2_FS_STATS if (!lockres->l_lock_wait && dlm_debug->d_filter_secs) { now = ktime_to_us(ktime_get_real()); if (lockres->l_lock_prmode.ls_last > lockres->l_lock_exmode.ls_last) last = lockres->l_lock_prmode.ls_last; else last = lockres->l_lock_exmode.ls_last; /* * Use d_filter_secs field to filter lock resources dump, * the default d_filter_secs(0) value filters nothing, * otherwise, only dump the last N seconds active lock * resources. */ if (div_u64(now - last, 1000000) > dlm_debug->d_filter_secs) return 0; } #endif 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) # define lock_last_prmode(_l) ((_l)->l_lock_prmode.ls_last) # define lock_last_exmode(_l) ((_l)->l_lock_exmode.ls_last) # define lock_wait(_l) ((_l)->l_lock_wait) #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) # define lock_last_prmode(_l) (0ULL) # define lock_last_exmode(_l) (0ULL) # define lock_wait(_l) (0ULL) #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" "%llu\t" "%llu\t" "%llu\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), lock_last_prmode(lockres), lock_last_exmode(lockres), lock_wait(lockres)); /* End the line */ seq_printf(m, "\n"); return 0; } static const struct seq_operations ocfs2_dlm_seq_ops = { .start = ocfs2_dlm_seq_start, .stop = ocfs2_dlm_seq_stop, .next = ocfs2_dlm_seq_next, .show = ocfs2_dlm_seq_show, }; static int ocfs2_dlm_debug_release(struct inode *inode, struct file *file) { struct seq_file *seq = file->private_data; struct ocfs2_dlm_seq_priv *priv = seq->private; struct ocfs2_lock_res *res = &priv->p_iter_res; ocfs2_remove_lockres_tracking(res); ocfs2_put_dlm_debug(priv->p_dlm_debug); return seq_release_private(inode, file); } static int ocfs2_dlm_debug_open(struct inode *inode, struct file *file) { struct ocfs2_dlm_seq_priv *priv; struct ocfs2_super *osb; priv = __seq_open_private(file, &ocfs2_dlm_seq_ops, sizeof(*priv)); if (!priv) { mlog_errno(-ENOMEM); return -ENOMEM; } osb = inode->i_private; ocfs2_get_dlm_debug(osb->osb_dlm_debug); priv->p_dlm_debug = osb->osb_dlm_debug; INIT_LIST_HEAD(&priv->p_iter_res.l_debug_list); ocfs2_add_lockres_tracking(&priv->p_iter_res, priv->p_dlm_debug); return 0; } static const struct file_operations ocfs2_dlm_debug_fops = { .open = ocfs2_dlm_debug_open, .release = ocfs2_dlm_debug_release, .read = seq_read, .llseek = seq_lseek, }; static void ocfs2_dlm_init_debug(struct ocfs2_super *osb) { struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; debugfs_create_file("locking_state", S_IFREG|S_IRUSR, osb->osb_debug_root, osb, &ocfs2_dlm_debug_fops); debugfs_create_u32("locking_filter", 0600, osb->osb_debug_root, &dlm_debug->d_filter_secs); ocfs2_get_dlm_debug(dlm_debug); } static void ocfs2_dlm_shutdown_debug(struct ocfs2_super *osb) { struct ocfs2_dlm_debug *dlm_debug = osb->osb_dlm_debug; if (dlm_debug) 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; } ocfs2_dlm_init_debug(osb); /* launch downconvert thread */ osb->dc_task = kthread_run(ocfs2_downconvert_thread, osb, "ocfs2dc-%s", osb->uuid_str); if (IS_ERR(osb->dc_task)) { status = PTR_ERR(osb->dc_task); osb->dc_task = NULL; mlog_errno(status); goto bail; } /* for now, uuid == domain */ status = ocfs2_cluster_connect(osb->osb_cluster_stack, osb->osb_cluster_name, strlen(osb->osb_cluster_name), osb->uuid_str, strlen(osb->uuid_str), &lproto, ocfs2_do_node_down, osb, &conn); if (status) { mlog_errno(status); goto bail; } status = ocfs2_cluster_this_node(conn, &osb->node_num); if (status < 0) { mlog_errno(status); mlog(ML_ERROR, "could not find this host's node number\n"); ocfs2_cluster_disconnect(conn, 0); goto bail; } local: ocfs2_super_lock_res_init(&osb->osb_super_lockres, osb); ocfs2_rename_lock_res_init(&osb->osb_rename_lockres, osb); ocfs2_nfs_sync_lock_init(osb); ocfs2_orphan_scan_lock_res_init(&osb->osb_orphan_scan.os_lockres, osb); osb->cconn = conn; 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); if (osb->cconn) { ocfs2_cluster_disconnect(osb->cconn, hangup_pending); osb->cconn = NULL; ocfs2_dlm_shutdown_debug(osb); } } static int ocfs2_drop_lock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres) { int ret; unsigned long flags; u32 lkm_flags = 0; /* We didn't get anywhere near actually using this lockres. */ if (!(lockres->l_flags & OCFS2_LOCK_INITIALIZED)) goto out; if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) lkm_flags |= DLM_LKF_VALBLK; spin_lock_irqsave(&lockres->l_lock, flags); mlog_bug_on_msg(!(lockres->l_flags & OCFS2_LOCK_FREEING), "lockres %s, flags 0x%lx\n", lockres->l_name, lockres->l_flags); while (lockres->l_flags & OCFS2_LOCK_BUSY) { mlog(0, "waiting on busy lock \"%s\": flags = %lx, action = " "%u, unlock_action = %u\n", lockres->l_name, lockres->l_flags, lockres->l_action, lockres->l_unlock_action); spin_unlock_irqrestore(&lockres->l_lock, flags); /* XXX: Today we just wait on any busy * locks... Perhaps we need to cancel converts in the * future? */ ocfs2_wait_on_busy_lock(lockres); spin_lock_irqsave(&lockres->l_lock, flags); } if (lockres->l_ops->flags & LOCK_TYPE_USES_LVB) { if (lockres->l_flags & OCFS2_LOCK_ATTACHED && lockres->l_level == DLM_LOCK_EX && !(lockres->l_flags & OCFS2_LOCK_NEEDS_REFRESH)) lockres->l_ops->set_lvb(lockres); } if (lockres->l_flags & OCFS2_LOCK_BUSY) mlog(ML_ERROR, "destroying busy lock: \"%s\"\n", lockres->l_name); if (lockres->l_flags & OCFS2_LOCK_BLOCKED) mlog(0, "destroying blocked lock: \"%s\"\n", lockres->l_name); if (!(lockres->l_flags & OCFS2_LOCK_ATTACHED)) { spin_unlock_irqrestore(&lockres->l_lock, flags); goto out; } lockres_clear_flags(lockres, OCFS2_LOCK_ATTACHED); /* make sure we never get here while waiting for an ast to * fire. */ BUG_ON(lockres->l_action != OCFS2_AST_INVALID); /* is this necessary? */ lockres_or_flags(lockres, OCFS2_LOCK_BUSY); lockres->l_unlock_action = OCFS2_UNLOCK_DROP_LOCK; spin_unlock_irqrestore(&lockres->l_lock, flags); mlog(0, "lock %s\n", lockres->l_name); ret = ocfs2_dlm_unlock(osb->cconn, &lockres->l_lksb, lkm_flags); if (ret) { ocfs2_log_dlm_error("ocfs2_dlm_unlock", ret, lockres); mlog(ML_ERROR, "lockres flags: %lu\n", lockres->l_flags); ocfs2_dlm_dump_lksb(&lockres->l_lksb); BUG(); } mlog(0, "lock %s, successful return from ocfs2_dlm_unlock\n", lockres->l_name); ocfs2_wait_on_busy_lock(lockres); out: return 0; } static void ocfs2_process_blocked_lock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres); /* Mark the lockres as being dropped. It will no longer be * queued if blocking, but we still may have to wait on it * being dequeued from the downconvert thread before we can consider * it safe to drop. * * You can *not* attempt to call cluster_lock on this lockres anymore. */ void ocfs2_mark_lockres_freeing(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres) { int status; struct ocfs2_mask_waiter mw; unsigned long flags, flags2; ocfs2_init_mask_waiter(&mw); spin_lock_irqsave(&lockres->l_lock, flags); lockres->l_flags |= OCFS2_LOCK_FREEING; if (lockres->l_flags & OCFS2_LOCK_QUEUED && current == osb->dc_task) { /* * We know the downconvert is queued but not in progress * because we are the downconvert thread and processing * different lock. So we can just remove the lock from the * queue. This is not only an optimization but also a way * to avoid the following deadlock: * ocfs2_dentry_post_unlock() * ocfs2_dentry_lock_put() * ocfs2_drop_dentry_lock() * iput() * ocfs2_evict_inode() * ocfs2_clear_inode() * ocfs2_mark_lockres_freeing() * ... blocks waiting for OCFS2_LOCK_QUEUED * since we are the downconvert thread which * should clear the flag. */ spin_unlock_irqrestore(&lockres->l_lock, flags); spin_lock_irqsave(&osb->dc_task_lock, flags2); list_del_init(&lockres->l_blocked_list); osb->blocked_lock_count--; spin_unlock_irqrestore(&osb->dc_task_lock, flags2); /* * Warn if we recurse into another post_unlock call. Strictly * speaking it isn't a problem but we need to be careful if * that happens (stack overflow, deadlocks, ...) so warn if * ocfs2 grows a path for which this can happen. */ WARN_ON_ONCE(lockres->l_ops->post_unlock); /* Since the lock is freeing we don't do much in the fn below */ ocfs2_process_blocked_lock(osb, lockres); return; } while (lockres->l_flags & OCFS2_LOCK_QUEUED) { lockres_add_mask_waiter(lockres, &mw, OCFS2_LOCK_QUEUED, 0); spin_unlock_irqrestore(&lockres->l_lock, flags); mlog(0, "Waiting on lockres %s\n", lockres->l_name); status = ocfs2_wait_for_mask(&mw); if (status) mlog_errno(status); spin_lock_irqsave(&lockres->l_lock, flags); } spin_unlock_irqrestore(&lockres->l_lock, flags); } void ocfs2_simple_drop_lockres(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres) { int ret; ocfs2_mark_lockres_freeing(osb, lockres); ret = ocfs2_drop_lock(osb, lockres); if (ret) mlog_errno(ret); } static void ocfs2_drop_osb_locks(struct ocfs2_super *osb) { ocfs2_simple_drop_lockres(osb, &osb->osb_super_lockres); ocfs2_simple_drop_lockres(osb, &osb->osb_rename_lockres); ocfs2_simple_drop_lockres(osb, &osb->osb_nfs_sync_lockres); ocfs2_simple_drop_lockres(osb, &osb->osb_orphan_scan.os_lockres); } int ocfs2_drop_inode_locks(struct inode *inode) { int status, err; /* No need to call ocfs2_mark_lockres_freeing here - * ocfs2_clear_inode has done it for us. */ err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), &OCFS2_I(inode)->ip_open_lockres); if (err < 0) mlog_errno(err); status = err; err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), &OCFS2_I(inode)->ip_inode_lockres); if (err < 0) mlog_errno(err); if (err < 0 && !status) status = err; err = ocfs2_drop_lock(OCFS2_SB(inode->i_sb), &OCFS2_I(inode)->ip_rw_lockres); if (err < 0) mlog_errno(err); if (err < 0 && !status) status = err; return status; } static unsigned int ocfs2_prepare_downconvert(struct ocfs2_lock_res *lockres, int new_level) { assert_spin_locked(&lockres->l_lock); BUG_ON(lockres->l_blocking <= DLM_LOCK_NL); if (lockres->l_level <= new_level) { mlog(ML_ERROR, "lockres %s, lvl %d <= %d, blcklst %d, mask %d, " "type %d, flags 0x%lx, hold %d %d, act %d %d, req %d, " "block %d, pgen %d\n", lockres->l_name, lockres->l_level, new_level, list_empty(&lockres->l_blocked_list), list_empty(&lockres->l_mask_waiters), lockres->l_type, lockres->l_flags, lockres->l_ro_holders, lockres->l_ex_holders, lockres->l_action, lockres->l_unlock_action, lockres->l_requested, lockres->l_blocking, lockres->l_pending_gen); BUG(); } mlog(ML_BASTS, "lockres %s, level %d => %d, blocking %d\n", lockres->l_name, lockres->l_level, new_level, lockres->l_blocking); lockres->l_action = OCFS2_AST_DOWNCONVERT; lockres->l_requested = new_level; lockres_or_flags(lockres, OCFS2_LOCK_BUSY); return lockres_set_pending(lockres); } static int ocfs2_downconvert_lock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres, int new_level, int lvb, unsigned int generation) { int ret; u32 dlm_flags = DLM_LKF_CONVERT; mlog(ML_BASTS, "lockres %s, level %d => %d\n", lockres->l_name, lockres->l_level, new_level); /* * On DLM_LKF_VALBLK, fsdlm behaves differently with o2cb. It always * expects DLM_LKF_VALBLK being set if the LKB has LVB, so that * we can recover correctly from node failure. Otherwise, we may get * invalid LVB in LKB, but without DLM_SBF_VALNOTVALID being set. */ if (ocfs2_userspace_stack(osb) && lockres->l_ops->flags & LOCK_TYPE_USES_LVB) lvb = 1; 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); /* The dlm lock convert is being cancelled in background, * ocfs2_cancel_convert() is asynchronous in fs/dlm, * requeue it, try again later. */ if (ret == -EBUSY) { ctl->requeue = 1; mlog(ML_BASTS, "lockres %s, ReQ: Downconvert busy\n", lockres->l_name); ret = 0; msleep(20); } 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_forget; } 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_forget: forget_all_cached_acls(inode); out: return UNBLOCK_CONTINUE; } static int ocfs2_ci_checkpointed(struct ocfs2_caching_info *ci, struct ocfs2_lock_res *lockres, int new_level) { int checkpointed = ocfs2_ci_fully_checkpointed(ci); BUG_ON(new_level != DLM_LOCK_NL && new_level != DLM_LOCK_PR); BUG_ON(lockres->l_level != DLM_LOCK_EX && !checkpointed); if (checkpointed) return 1; ocfs2_start_checkpoint(OCFS2_SB(ocfs2_metadata_cache_get_super(ci))); return 0; } static int ocfs2_check_meta_downconvert(struct ocfs2_lock_res *lockres, int new_level) { struct inode *inode = ocfs2_lock_res_inode(lockres); return ocfs2_ci_checkpointed(INODE_CACHE(inode), lockres, new_level); } static void ocfs2_set_meta_lvb(struct ocfs2_lock_res *lockres) { struct inode *inode = ocfs2_lock_res_inode(lockres); __ocfs2_stuff_meta_lvb(inode); } /* * Does the final reference drop on our dentry lock. Right now this * happens in the downconvert thread, but we could choose to simplify the * dlmglue API and push these off to the ocfs2_wq in the future. */ static void ocfs2_dentry_post_unlock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres) { struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); ocfs2_dentry_lock_put(osb, dl); } /* * d_delete() matching dentries before the lock downconvert. * * At this point, any process waiting to destroy the * dentry_lock due to last ref count is stopped by the * OCFS2_LOCK_QUEUED flag. * * We have two potential problems * * 1) If we do the last reference drop on our dentry_lock (via dput) * we'll wind up in ocfs2_release_dentry_lock(), waiting on * the downconvert to finish. Instead we take an elevated * reference and push the drop until after we've completed our * unblock processing. * * 2) There might be another process with a final reference, * waiting on us to finish processing. If this is the case, we * detect it and exit out - there's no more dentries anyway. */ static int ocfs2_dentry_convert_worker(struct ocfs2_lock_res *lockres, int blocking) { struct ocfs2_dentry_lock *dl = ocfs2_lock_res_dl(lockres); struct ocfs2_inode_info *oi = OCFS2_I(dl->dl_inode); struct dentry *dentry; unsigned long flags; int extra_ref = 0; /* * This node is blocking another node from getting a read * lock. This happens when we've renamed within a * directory. We've forced the other nodes to d_delete(), but * we never actually dropped our lock because it's still * valid. The downconvert code will retain a PR for this node, * so there's no further work to do. */ if (blocking == DLM_LOCK_PR) return UNBLOCK_CONTINUE; /* * Mark this inode as potentially orphaned. The code in * ocfs2_delete_inode() will figure out whether it actually * needs to be freed or not. */ spin_lock(&oi->ip_lock); oi->ip_flags |= OCFS2_INODE_MAYBE_ORPHANED; spin_unlock(&oi->ip_lock); /* * Yuck. We need to make sure however that the check of * OCFS2_LOCK_FREEING and the extra reference are atomic with * respect to a reference decrement or the setting of that * flag. */ spin_lock_irqsave(&lockres->l_lock, flags); spin_lock(&dentry_attach_lock); if (!(lockres->l_flags & OCFS2_LOCK_FREEING) && dl->dl_count) { dl->dl_count++; extra_ref = 1; } spin_unlock(&dentry_attach_lock); spin_unlock_irqrestore(&lockres->l_lock, flags); mlog(0, "extra_ref = %d\n", extra_ref); /* * We have a process waiting on us in ocfs2_dentry_iput(), * which means we can't have any more outstanding * aliases. There's no need to do any more work. */ if (!extra_ref) return UNBLOCK_CONTINUE; spin_lock(&dentry_attach_lock); while (1) { dentry = ocfs2_find_local_alias(dl->dl_inode, dl->dl_parent_blkno, 1); if (!dentry) break; spin_unlock(&dentry_attach_lock); if (S_ISDIR(dl->dl_inode->i_mode)) shrink_dcache_parent(dentry); mlog(0, "d_delete(%pd);\n", dentry); /* * The following dcache calls may do an * iput(). Normally we don't want that from the * downconverting thread, but in this case it's ok * because the requesting node already has an * exclusive lock on the inode, so it can't be queued * for a downconvert. */ d_delete(dentry); dput(dentry); spin_lock(&dentry_attach_lock); } spin_unlock(&dentry_attach_lock); /* * If we are the last holder of this dentry lock, there is no * reason to downconvert so skip straight to the unlock. */ if (dl->dl_count == 1) return UNBLOCK_STOP_POST; return UNBLOCK_CONTINUE_POST; } static int ocfs2_check_refcount_downconvert(struct ocfs2_lock_res *lockres, int new_level) { struct ocfs2_refcount_tree *tree = ocfs2_lock_res_refcount_tree(lockres); return ocfs2_ci_checkpointed(&tree->rf_ci, lockres, new_level); } static int ocfs2_refcount_convert_worker(struct ocfs2_lock_res *lockres, int blocking) { struct ocfs2_refcount_tree *tree = ocfs2_lock_res_refcount_tree(lockres); ocfs2_metadata_cache_purge(&tree->rf_ci); return UNBLOCK_CONTINUE; } static void ocfs2_set_qinfo_lvb(struct ocfs2_lock_res *lockres) { struct ocfs2_qinfo_lvb *lvb; struct ocfs2_mem_dqinfo *oinfo = ocfs2_lock_res_qinfo(lockres); struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb, oinfo->dqi_gi.dqi_type); lvb = ocfs2_dlm_lvb(&lockres->l_lksb); lvb->lvb_version = OCFS2_QINFO_LVB_VERSION; lvb->lvb_bgrace = cpu_to_be32(info->dqi_bgrace); lvb->lvb_igrace = cpu_to_be32(info->dqi_igrace); lvb->lvb_syncms = cpu_to_be32(oinfo->dqi_syncms); lvb->lvb_blocks = cpu_to_be32(oinfo->dqi_gi.dqi_blocks); lvb->lvb_free_blk = cpu_to_be32(oinfo->dqi_gi.dqi_free_blk); lvb->lvb_free_entry = cpu_to_be32(oinfo->dqi_gi.dqi_free_entry); } void ocfs2_qinfo_unlock(struct ocfs2_mem_dqinfo *oinfo, int ex) { struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb); int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; if (!ocfs2_is_hard_readonly(osb) && !ocfs2_mount_local(osb)) ocfs2_cluster_unlock(osb, lockres, level); } static int ocfs2_refresh_qinfo(struct ocfs2_mem_dqinfo *oinfo) { struct mem_dqinfo *info = sb_dqinfo(oinfo->dqi_gi.dqi_sb, oinfo->dqi_gi.dqi_type); struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; struct ocfs2_qinfo_lvb *lvb = ocfs2_dlm_lvb(&lockres->l_lksb); struct buffer_head *bh = NULL; struct ocfs2_global_disk_dqinfo *gdinfo; int status = 0; if (ocfs2_dlm_lvb_valid(&lockres->l_lksb) && lvb->lvb_version == OCFS2_QINFO_LVB_VERSION) { info->dqi_bgrace = be32_to_cpu(lvb->lvb_bgrace); info->dqi_igrace = be32_to_cpu(lvb->lvb_igrace); oinfo->dqi_syncms = be32_to_cpu(lvb->lvb_syncms); oinfo->dqi_gi.dqi_blocks = be32_to_cpu(lvb->lvb_blocks); oinfo->dqi_gi.dqi_free_blk = be32_to_cpu(lvb->lvb_free_blk); oinfo->dqi_gi.dqi_free_entry = be32_to_cpu(lvb->lvb_free_entry); } else { status = ocfs2_read_quota_phys_block(oinfo->dqi_gqinode, oinfo->dqi_giblk, &bh); if (status) { mlog_errno(status); goto bail; } gdinfo = (struct ocfs2_global_disk_dqinfo *) (bh->b_data + OCFS2_GLOBAL_INFO_OFF); info->dqi_bgrace = le32_to_cpu(gdinfo->dqi_bgrace); info->dqi_igrace = le32_to_cpu(gdinfo->dqi_igrace); oinfo->dqi_syncms = le32_to_cpu(gdinfo->dqi_syncms); oinfo->dqi_gi.dqi_blocks = le32_to_cpu(gdinfo->dqi_blocks); oinfo->dqi_gi.dqi_free_blk = le32_to_cpu(gdinfo->dqi_free_blk); oinfo->dqi_gi.dqi_free_entry = le32_to_cpu(gdinfo->dqi_free_entry); brelse(bh); ocfs2_track_lock_refresh(lockres); } bail: return status; } /* Lock quota info, this function expects at least shared lock on the quota file * so that we can safely refresh quota info from disk. */ int ocfs2_qinfo_lock(struct ocfs2_mem_dqinfo *oinfo, int ex) { struct ocfs2_lock_res *lockres = &oinfo->dqi_gqlock; struct ocfs2_super *osb = OCFS2_SB(oinfo->dqi_gi.dqi_sb); int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; int status = 0; /* On RO devices, locking really isn't needed... */ if (ocfs2_is_hard_readonly(osb)) { if (ex) status = -EROFS; goto bail; } if (ocfs2_mount_local(osb)) goto bail; status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); if (status < 0) { mlog_errno(status); goto bail; } if (!ocfs2_should_refresh_lock_res(lockres)) goto bail; /* OK, we have the lock but we need to refresh the quota info */ status = ocfs2_refresh_qinfo(oinfo); if (status) ocfs2_qinfo_unlock(oinfo, ex); ocfs2_complete_lock_res_refresh(lockres, status); bail: return status; } int ocfs2_refcount_lock(struct ocfs2_refcount_tree *ref_tree, int ex) { int status; int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres; struct ocfs2_super *osb = lockres->l_priv; if (ocfs2_is_hard_readonly(osb)) return -EROFS; if (ocfs2_mount_local(osb)) return 0; status = ocfs2_cluster_lock(osb, lockres, level, 0, 0); if (status < 0) mlog_errno(status); return status; } void ocfs2_refcount_unlock(struct ocfs2_refcount_tree *ref_tree, int ex) { int level = ex ? DLM_LOCK_EX : DLM_LOCK_PR; struct ocfs2_lock_res *lockres = &ref_tree->rf_lockres; struct ocfs2_super *osb = lockres->l_priv; if (!ocfs2_mount_local(osb)) ocfs2_cluster_unlock(osb, lockres, level); } static void ocfs2_process_blocked_lock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres) { int status; struct ocfs2_unblock_ctl ctl = {0, 0,}; unsigned long flags; /* Our reference to the lockres in this function can be * considered valid until we remove the OCFS2_LOCK_QUEUED * flag. */ BUG_ON(!lockres); BUG_ON(!lockres->l_ops); mlog(ML_BASTS, "lockres %s blocked\n", lockres->l_name); /* Detect whether a lock has been marked as going away while * the downconvert thread was processing other things. A lock can * still be marked with OCFS2_LOCK_FREEING after this check, * but short circuiting here will still save us some * performance. */ spin_lock_irqsave(&lockres->l_lock, flags); if (lockres->l_flags & OCFS2_LOCK_FREEING) goto unqueue; spin_unlock_irqrestore(&lockres->l_lock, flags); status = ocfs2_unblock_lock(osb, lockres, &ctl); if (status < 0) mlog_errno(status); spin_lock_irqsave(&lockres->l_lock, flags); unqueue: if (lockres->l_flags & OCFS2_LOCK_FREEING || !ctl.requeue) { lockres_clear_flags(lockres, OCFS2_LOCK_QUEUED); } else ocfs2_schedule_blocked_lock(osb, lockres); mlog(ML_BASTS, "lockres %s, requeue = %s.\n", lockres->l_name, ctl.requeue ? "yes" : "no"); spin_unlock_irqrestore(&lockres->l_lock, flags); if (ctl.unblock_action != UNBLOCK_CONTINUE && lockres->l_ops->post_unlock) lockres->l_ops->post_unlock(osb, lockres); } static void ocfs2_schedule_blocked_lock(struct ocfs2_super *osb, struct ocfs2_lock_res *lockres) { unsigned long flags; assert_spin_locked(&lockres->l_lock); if (lockres->l_flags & OCFS2_LOCK_FREEING) { /* Do not schedule a lock for downconvert when it's on * the way to destruction - any nodes wanting access * to the resource will get it soon. */ mlog(ML_BASTS, "lockres %s won't be scheduled: flags 0x%lx\n", lockres->l_name, lockres->l_flags); return; } lockres_or_flags(lockres, OCFS2_LOCK_QUEUED); spin_lock_irqsave(&osb->dc_task_lock, flags); if (list_empty(&lockres->l_blocked_list)) { list_add_tail(&lockres->l_blocked_list, &osb->blocked_lock_list); osb->blocked_lock_count++; } spin_unlock_irqrestore(&osb->dc_task_lock, flags); } static void ocfs2_downconvert_thread_do_work(struct ocfs2_super *osb) { unsigned long processed; unsigned long flags; struct ocfs2_lock_res *lockres; spin_lock_irqsave(&osb->dc_task_lock, flags); /* grab this early so we know to try again if a state change and * wake happens part-way through our work */ osb->dc_work_sequence = osb->dc_wake_sequence; processed = osb->blocked_lock_count; /* * 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_irqrestore(&osb->dc_task_lock, flags); BUG_ON(!processed); processed--; ocfs2_process_blocked_lock(osb, lockres); spin_lock_irqsave(&osb->dc_task_lock, flags); } spin_unlock_irqrestore(&osb->dc_task_lock, flags); } static int ocfs2_downconvert_thread_lists_empty(struct ocfs2_super *osb) { int empty = 0; unsigned long flags; spin_lock_irqsave(&osb->dc_task_lock, flags); if (list_empty(&osb->blocked_lock_list)) empty = 1; spin_unlock_irqrestore(&osb->dc_task_lock, flags); return empty; } static int ocfs2_downconvert_thread_should_wake(struct ocfs2_super *osb) { int should_wake = 0; unsigned long flags; spin_lock_irqsave(&osb->dc_task_lock, flags); if (osb->dc_work_sequence != osb->dc_wake_sequence) should_wake = 1; spin_unlock_irqrestore(&osb->dc_task_lock, flags); return should_wake; } static int ocfs2_downconvert_thread(void *arg) { 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 0; } void ocfs2_wake_downconvert_thread(struct ocfs2_super *osb) { unsigned long flags; spin_lock_irqsave(&osb->dc_task_lock, flags); /* make sure the voting thread gets a swipe at whatever changes * the caller may have made to the voting state */ osb->dc_wake_sequence++; spin_unlock_irqrestore(&osb->dc_task_lock, flags); wake_up(&osb->dc_event); }
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