| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. |
| * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. |
| */ |
| |
| #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
| |
| #include <linux/sched.h> |
| #include <linux/slab.h> |
| #include <linux/spinlock.h> |
| #include <linux/buffer_head.h> |
| #include <linux/delay.h> |
| #include <linux/sort.h> |
| #include <linux/hash.h> |
| #include <linux/jhash.h> |
| #include <linux/kallsyms.h> |
| #include <linux/gfs2_ondisk.h> |
| #include <linux/list.h> |
| #include <linux/wait.h> |
| #include <linux/module.h> |
| #include <linux/uaccess.h> |
| #include <linux/seq_file.h> |
| #include <linux/debugfs.h> |
| #include <linux/kthread.h> |
| #include <linux/freezer.h> |
| #include <linux/workqueue.h> |
| #include <linux/jiffies.h> |
| #include <linux/rcupdate.h> |
| #include <linux/rculist_bl.h> |
| #include <linux/bit_spinlock.h> |
| #include <linux/percpu.h> |
| #include <linux/list_sort.h> |
| #include <linux/lockref.h> |
| #include <linux/rhashtable.h> |
| #include <linux/pid_namespace.h> |
| #include <linux/fdtable.h> |
| #include <linux/file.h> |
| |
| #include "gfs2.h" |
| #include "incore.h" |
| #include "glock.h" |
| #include "glops.h" |
| #include "inode.h" |
| #include "lops.h" |
| #include "meta_io.h" |
| #include "quota.h" |
| #include "super.h" |
| #include "util.h" |
| #include "bmap.h" |
| #define CREATE_TRACE_POINTS |
| #include "trace_gfs2.h" |
| |
| struct gfs2_glock_iter { |
| struct gfs2_sbd *sdp; /* incore superblock */ |
| struct rhashtable_iter hti; /* rhashtable iterator */ |
| struct gfs2_glock *gl; /* current glock struct */ |
| loff_t last_pos; /* last position */ |
| }; |
| |
| typedef void (*glock_examiner) (struct gfs2_glock * gl); |
| |
| static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, unsigned int target); |
| static void __gfs2_glock_dq(struct gfs2_holder *gh); |
| static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
| unsigned long delay, bool remote); |
| |
| static struct dentry *gfs2_root; |
| static struct workqueue_struct *glock_workqueue; |
| static LIST_HEAD(lru_list); |
| static atomic_t lru_count = ATOMIC_INIT(0); |
| static DEFINE_SPINLOCK(lru_lock); |
| |
| #define GFS2_GL_HASH_SHIFT 15 |
| #define GFS2_GL_HASH_SIZE BIT(GFS2_GL_HASH_SHIFT) |
| |
| static const struct rhashtable_params ht_parms = { |
| .nelem_hint = GFS2_GL_HASH_SIZE * 3 / 4, |
| .key_len = offsetofend(struct lm_lockname, ln_type), |
| .key_offset = offsetof(struct gfs2_glock, gl_name), |
| .head_offset = offsetof(struct gfs2_glock, gl_node), |
| }; |
| |
| static struct rhashtable gl_hash_table; |
| |
| #define GLOCK_WAIT_TABLE_BITS 12 |
| #define GLOCK_WAIT_TABLE_SIZE (1 << GLOCK_WAIT_TABLE_BITS) |
| static wait_queue_head_t glock_wait_table[GLOCK_WAIT_TABLE_SIZE] __cacheline_aligned; |
| |
| struct wait_glock_queue { |
| struct lm_lockname *name; |
| wait_queue_entry_t wait; |
| }; |
| |
| static int glock_wake_function(wait_queue_entry_t *wait, unsigned int mode, |
| int sync, void *key) |
| { |
| struct wait_glock_queue *wait_glock = |
| container_of(wait, struct wait_glock_queue, wait); |
| struct lm_lockname *wait_name = wait_glock->name; |
| struct lm_lockname *wake_name = key; |
| |
| if (wake_name->ln_sbd != wait_name->ln_sbd || |
| wake_name->ln_number != wait_name->ln_number || |
| wake_name->ln_type != wait_name->ln_type) |
| return 0; |
| return autoremove_wake_function(wait, mode, sync, key); |
| } |
| |
| static wait_queue_head_t *glock_waitqueue(struct lm_lockname *name) |
| { |
| u32 hash = jhash2((u32 *)name, ht_parms.key_len / 4, 0); |
| |
| return glock_wait_table + hash_32(hash, GLOCK_WAIT_TABLE_BITS); |
| } |
| |
| /** |
| * wake_up_glock - Wake up waiters on a glock |
| * @gl: the glock |
| */ |
| static void wake_up_glock(struct gfs2_glock *gl) |
| { |
| wait_queue_head_t *wq = glock_waitqueue(&gl->gl_name); |
| |
| if (waitqueue_active(wq)) |
| __wake_up(wq, TASK_NORMAL, 1, &gl->gl_name); |
| } |
| |
| static void gfs2_glock_dealloc(struct rcu_head *rcu) |
| { |
| struct gfs2_glock *gl = container_of(rcu, struct gfs2_glock, gl_rcu); |
| |
| kfree(gl->gl_lksb.sb_lvbptr); |
| if (gl->gl_ops->go_flags & GLOF_ASPACE) { |
| struct gfs2_glock_aspace *gla = |
| container_of(gl, struct gfs2_glock_aspace, glock); |
| kmem_cache_free(gfs2_glock_aspace_cachep, gla); |
| } else |
| kmem_cache_free(gfs2_glock_cachep, gl); |
| } |
| |
| /** |
| * glock_blocked_by_withdraw - determine if we can still use a glock |
| * @gl: the glock |
| * |
| * We need to allow some glocks to be enqueued, dequeued, promoted, and demoted |
| * when we're withdrawn. For example, to maintain metadata integrity, we should |
| * disallow the use of inode and rgrp glocks when withdrawn. Other glocks like |
| * the iopen or freeze glock may be safely used because none of their |
| * metadata goes through the journal. So in general, we should disallow all |
| * glocks that are journaled, and allow all the others. One exception is: |
| * we need to allow our active journal to be promoted and demoted so others |
| * may recover it and we can reacquire it when they're done. |
| */ |
| static bool glock_blocked_by_withdraw(struct gfs2_glock *gl) |
| { |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| |
| if (likely(!gfs2_withdrawn(sdp))) |
| return false; |
| if (gl->gl_ops->go_flags & GLOF_NONDISK) |
| return false; |
| if (!sdp->sd_jdesc || |
| gl->gl_name.ln_number == sdp->sd_jdesc->jd_no_addr) |
| return false; |
| return true; |
| } |
| |
| void gfs2_glock_free(struct gfs2_glock *gl) |
| { |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| |
| gfs2_glock_assert_withdraw(gl, atomic_read(&gl->gl_revokes) == 0); |
| rhashtable_remove_fast(&gl_hash_table, &gl->gl_node, ht_parms); |
| smp_mb(); |
| wake_up_glock(gl); |
| call_rcu(&gl->gl_rcu, gfs2_glock_dealloc); |
| if (atomic_dec_and_test(&sdp->sd_glock_disposal)) |
| wake_up(&sdp->sd_kill_wait); |
| } |
| |
| /** |
| * gfs2_glock_hold() - increment reference count on glock |
| * @gl: The glock to hold |
| * |
| */ |
| |
| struct gfs2_glock *gfs2_glock_hold(struct gfs2_glock *gl) |
| { |
| GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref)); |
| lockref_get(&gl->gl_lockref); |
| return gl; |
| } |
| |
| /** |
| * demote_ok - Check to see if it's ok to unlock a glock |
| * @gl: the glock |
| * |
| * Returns: 1 if it's ok |
| */ |
| |
| static int demote_ok(const struct gfs2_glock *gl) |
| { |
| const struct gfs2_glock_operations *glops = gl->gl_ops; |
| |
| if (gl->gl_state == LM_ST_UNLOCKED) |
| return 0; |
| if (!list_empty(&gl->gl_holders)) |
| return 0; |
| if (glops->go_demote_ok) |
| return glops->go_demote_ok(gl); |
| return 1; |
| } |
| |
| |
| void gfs2_glock_add_to_lru(struct gfs2_glock *gl) |
| { |
| if (!(gl->gl_ops->go_flags & GLOF_LRU)) |
| return; |
| |
| spin_lock(&lru_lock); |
| |
| list_move_tail(&gl->gl_lru, &lru_list); |
| |
| if (!test_bit(GLF_LRU, &gl->gl_flags)) { |
| set_bit(GLF_LRU, &gl->gl_flags); |
| atomic_inc(&lru_count); |
| } |
| |
| spin_unlock(&lru_lock); |
| } |
| |
| static void gfs2_glock_remove_from_lru(struct gfs2_glock *gl) |
| { |
| if (!(gl->gl_ops->go_flags & GLOF_LRU)) |
| return; |
| |
| spin_lock(&lru_lock); |
| if (test_bit(GLF_LRU, &gl->gl_flags)) { |
| list_del_init(&gl->gl_lru); |
| atomic_dec(&lru_count); |
| clear_bit(GLF_LRU, &gl->gl_flags); |
| } |
| spin_unlock(&lru_lock); |
| } |
| |
| /* |
| * Enqueue the glock on the work queue. Passes one glock reference on to the |
| * work queue. |
| */ |
| static void __gfs2_glock_queue_work(struct gfs2_glock *gl, unsigned long delay) { |
| if (!queue_delayed_work(glock_workqueue, &gl->gl_work, delay)) { |
| /* |
| * We are holding the lockref spinlock, and the work was still |
| * queued above. The queued work (glock_work_func) takes that |
| * spinlock before dropping its glock reference(s), so it |
| * cannot have dropped them in the meantime. |
| */ |
| GLOCK_BUG_ON(gl, gl->gl_lockref.count < 2); |
| gl->gl_lockref.count--; |
| } |
| } |
| |
| static void gfs2_glock_queue_work(struct gfs2_glock *gl, unsigned long delay) { |
| spin_lock(&gl->gl_lockref.lock); |
| __gfs2_glock_queue_work(gl, delay); |
| spin_unlock(&gl->gl_lockref.lock); |
| } |
| |
| static void __gfs2_glock_put(struct gfs2_glock *gl) |
| { |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| struct address_space *mapping = gfs2_glock2aspace(gl); |
| |
| lockref_mark_dead(&gl->gl_lockref); |
| spin_unlock(&gl->gl_lockref.lock); |
| gfs2_glock_remove_from_lru(gl); |
| GLOCK_BUG_ON(gl, !list_empty(&gl->gl_holders)); |
| if (mapping) { |
| truncate_inode_pages_final(mapping); |
| if (!gfs2_withdrawn(sdp)) |
| GLOCK_BUG_ON(gl, !mapping_empty(mapping)); |
| } |
| trace_gfs2_glock_put(gl); |
| sdp->sd_lockstruct.ls_ops->lm_put_lock(gl); |
| } |
| |
| /* |
| * Cause the glock to be put in work queue context. |
| */ |
| void gfs2_glock_queue_put(struct gfs2_glock *gl) |
| { |
| gfs2_glock_queue_work(gl, 0); |
| } |
| |
| /** |
| * gfs2_glock_put() - Decrement reference count on glock |
| * @gl: The glock to put |
| * |
| */ |
| |
| void gfs2_glock_put(struct gfs2_glock *gl) |
| { |
| if (lockref_put_or_lock(&gl->gl_lockref)) |
| return; |
| |
| __gfs2_glock_put(gl); |
| } |
| |
| /** |
| * may_grant - check if it's ok to grant a new lock |
| * @gl: The glock |
| * @current_gh: One of the current holders of @gl |
| * @gh: The lock request which we wish to grant |
| * |
| * With our current compatibility rules, if a glock has one or more active |
| * holders (HIF_HOLDER flag set), any of those holders can be passed in as |
| * @current_gh; they are all the same as far as compatibility with the new @gh |
| * goes. |
| * |
| * Returns true if it's ok to grant the lock. |
| */ |
| |
| static inline bool may_grant(struct gfs2_glock *gl, |
| struct gfs2_holder *current_gh, |
| struct gfs2_holder *gh) |
| { |
| if (current_gh) { |
| GLOCK_BUG_ON(gl, !test_bit(HIF_HOLDER, ¤t_gh->gh_iflags)); |
| |
| switch(current_gh->gh_state) { |
| case LM_ST_EXCLUSIVE: |
| /* |
| * Here we make a special exception to grant holders |
| * who agree to share the EX lock with other holders |
| * who also have the bit set. If the original holder |
| * has the LM_FLAG_NODE_SCOPE bit set, we grant more |
| * holders with the bit set. |
| */ |
| return gh->gh_state == LM_ST_EXCLUSIVE && |
| (current_gh->gh_flags & LM_FLAG_NODE_SCOPE) && |
| (gh->gh_flags & LM_FLAG_NODE_SCOPE); |
| |
| case LM_ST_SHARED: |
| case LM_ST_DEFERRED: |
| return gh->gh_state == current_gh->gh_state; |
| |
| default: |
| return false; |
| } |
| } |
| |
| if (gl->gl_state == gh->gh_state) |
| return true; |
| if (gh->gh_flags & GL_EXACT) |
| return false; |
| if (gl->gl_state == LM_ST_EXCLUSIVE) { |
| return gh->gh_state == LM_ST_SHARED || |
| gh->gh_state == LM_ST_DEFERRED; |
| } |
| if (gh->gh_flags & LM_FLAG_ANY) |
| return gl->gl_state != LM_ST_UNLOCKED; |
| return false; |
| } |
| |
| static void gfs2_holder_wake(struct gfs2_holder *gh) |
| { |
| clear_bit(HIF_WAIT, &gh->gh_iflags); |
| smp_mb__after_atomic(); |
| wake_up_bit(&gh->gh_iflags, HIF_WAIT); |
| if (gh->gh_flags & GL_ASYNC) { |
| struct gfs2_sbd *sdp = gh->gh_gl->gl_name.ln_sbd; |
| |
| wake_up(&sdp->sd_async_glock_wait); |
| } |
| } |
| |
| /** |
| * do_error - Something unexpected has happened during a lock request |
| * @gl: The glock |
| * @ret: The status from the DLM |
| */ |
| |
| static void do_error(struct gfs2_glock *gl, const int ret) |
| { |
| struct gfs2_holder *gh, *tmp; |
| |
| list_for_each_entry_safe(gh, tmp, &gl->gl_holders, gh_list) { |
| if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| continue; |
| if (ret & LM_OUT_ERROR) |
| gh->gh_error = -EIO; |
| else if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) |
| gh->gh_error = GLR_TRYFAILED; |
| else |
| continue; |
| list_del_init(&gh->gh_list); |
| trace_gfs2_glock_queue(gh, 0); |
| gfs2_holder_wake(gh); |
| } |
| } |
| |
| /** |
| * find_first_holder - find the first "holder" gh |
| * @gl: the glock |
| */ |
| |
| static inline struct gfs2_holder *find_first_holder(const struct gfs2_glock *gl) |
| { |
| struct gfs2_holder *gh; |
| |
| if (!list_empty(&gl->gl_holders)) { |
| gh = list_first_entry(&gl->gl_holders, struct gfs2_holder, |
| gh_list); |
| if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| return gh; |
| } |
| return NULL; |
| } |
| |
| /* |
| * gfs2_instantiate - Call the glops instantiate function |
| * @gh: The glock holder |
| * |
| * Returns: 0 if instantiate was successful, or error. |
| */ |
| int gfs2_instantiate(struct gfs2_holder *gh) |
| { |
| struct gfs2_glock *gl = gh->gh_gl; |
| const struct gfs2_glock_operations *glops = gl->gl_ops; |
| int ret; |
| |
| again: |
| if (!test_bit(GLF_INSTANTIATE_NEEDED, &gl->gl_flags)) |
| goto done; |
| |
| /* |
| * Since we unlock the lockref lock, we set a flag to indicate |
| * instantiate is in progress. |
| */ |
| if (test_and_set_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags)) { |
| wait_on_bit(&gl->gl_flags, GLF_INSTANTIATE_IN_PROG, |
| TASK_UNINTERRUPTIBLE); |
| /* |
| * Here we just waited for a different instantiate to finish. |
| * But that may not have been successful, as when a process |
| * locks an inode glock _before_ it has an actual inode to |
| * instantiate into. So we check again. This process might |
| * have an inode to instantiate, so might be successful. |
| */ |
| goto again; |
| } |
| |
| ret = glops->go_instantiate(gl); |
| if (!ret) |
| clear_bit(GLF_INSTANTIATE_NEEDED, &gl->gl_flags); |
| clear_and_wake_up_bit(GLF_INSTANTIATE_IN_PROG, &gl->gl_flags); |
| if (ret) |
| return ret; |
| |
| done: |
| if (glops->go_held) |
| return glops->go_held(gh); |
| return 0; |
| } |
| |
| /** |
| * do_promote - promote as many requests as possible on the current queue |
| * @gl: The glock |
| * |
| * Returns true on success (i.e., progress was made or there are no waiters). |
| */ |
| |
| static bool do_promote(struct gfs2_glock *gl) |
| { |
| struct gfs2_holder *gh, *current_gh; |
| |
| current_gh = find_first_holder(gl); |
| list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
| if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| continue; |
| if (!may_grant(gl, current_gh, gh)) { |
| /* |
| * If we get here, it means we may not grant this |
| * holder for some reason. If this holder is at the |
| * head of the list, it means we have a blocked holder |
| * at the head, so return false. |
| */ |
| if (list_is_first(&gh->gh_list, &gl->gl_holders)) |
| return false; |
| do_error(gl, 0); |
| break; |
| } |
| set_bit(HIF_HOLDER, &gh->gh_iflags); |
| trace_gfs2_promote(gh); |
| gfs2_holder_wake(gh); |
| if (!current_gh) |
| current_gh = gh; |
| } |
| return true; |
| } |
| |
| /** |
| * find_first_waiter - find the first gh that's waiting for the glock |
| * @gl: the glock |
| */ |
| |
| static inline struct gfs2_holder *find_first_waiter(const struct gfs2_glock *gl) |
| { |
| struct gfs2_holder *gh; |
| |
| list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
| if (!test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| return gh; |
| } |
| return NULL; |
| } |
| |
| /** |
| * state_change - record that the glock is now in a different state |
| * @gl: the glock |
| * @new_state: the new state |
| */ |
| |
| static void state_change(struct gfs2_glock *gl, unsigned int new_state) |
| { |
| int held1, held2; |
| |
| held1 = (gl->gl_state != LM_ST_UNLOCKED); |
| held2 = (new_state != LM_ST_UNLOCKED); |
| |
| if (held1 != held2) { |
| GLOCK_BUG_ON(gl, __lockref_is_dead(&gl->gl_lockref)); |
| if (held2) |
| gl->gl_lockref.count++; |
| else |
| gl->gl_lockref.count--; |
| } |
| if (new_state != gl->gl_target) |
| /* shorten our minimum hold time */ |
| gl->gl_hold_time = max(gl->gl_hold_time - GL_GLOCK_HOLD_DECR, |
| GL_GLOCK_MIN_HOLD); |
| gl->gl_state = new_state; |
| gl->gl_tchange = jiffies; |
| } |
| |
| static void gfs2_set_demote(struct gfs2_glock *gl) |
| { |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| |
| set_bit(GLF_DEMOTE, &gl->gl_flags); |
| smp_mb(); |
| wake_up(&sdp->sd_async_glock_wait); |
| } |
| |
| static void gfs2_demote_wake(struct gfs2_glock *gl) |
| { |
| gl->gl_demote_state = LM_ST_EXCLUSIVE; |
| clear_bit(GLF_DEMOTE, &gl->gl_flags); |
| smp_mb__after_atomic(); |
| wake_up_bit(&gl->gl_flags, GLF_DEMOTE); |
| } |
| |
| /** |
| * finish_xmote - The DLM has replied to one of our lock requests |
| * @gl: The glock |
| * @ret: The status from the DLM |
| * |
| */ |
| |
| static void finish_xmote(struct gfs2_glock *gl, unsigned int ret) |
| { |
| const struct gfs2_glock_operations *glops = gl->gl_ops; |
| struct gfs2_holder *gh; |
| unsigned state = ret & LM_OUT_ST_MASK; |
| |
| spin_lock(&gl->gl_lockref.lock); |
| trace_gfs2_glock_state_change(gl, state); |
| state_change(gl, state); |
| gh = find_first_waiter(gl); |
| |
| /* Demote to UN request arrived during demote to SH or DF */ |
| if (test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags) && |
| state != LM_ST_UNLOCKED && gl->gl_demote_state == LM_ST_UNLOCKED) |
| gl->gl_target = LM_ST_UNLOCKED; |
| |
| /* Check for state != intended state */ |
| if (unlikely(state != gl->gl_target)) { |
| if (gh && (ret & LM_OUT_CANCELED)) |
| gfs2_holder_wake(gh); |
| if (gh && !test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) { |
| /* move to back of queue and try next entry */ |
| if (ret & LM_OUT_CANCELED) { |
| list_move_tail(&gh->gh_list, &gl->gl_holders); |
| gh = find_first_waiter(gl); |
| gl->gl_target = gh->gh_state; |
| if (do_promote(gl)) |
| goto out; |
| goto retry; |
| } |
| /* Some error or failed "try lock" - report it */ |
| if ((ret & LM_OUT_ERROR) || |
| (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { |
| gl->gl_target = gl->gl_state; |
| do_error(gl, ret); |
| goto out; |
| } |
| } |
| switch(state) { |
| /* Unlocked due to conversion deadlock, try again */ |
| case LM_ST_UNLOCKED: |
| retry: |
| do_xmote(gl, gh, gl->gl_target); |
| break; |
| /* Conversion fails, unlock and try again */ |
| case LM_ST_SHARED: |
| case LM_ST_DEFERRED: |
| do_xmote(gl, gh, LM_ST_UNLOCKED); |
| break; |
| default: /* Everything else */ |
| fs_err(gl->gl_name.ln_sbd, "wanted %u got %u\n", |
| gl->gl_target, state); |
| GLOCK_BUG_ON(gl, 1); |
| } |
| spin_unlock(&gl->gl_lockref.lock); |
| return; |
| } |
| |
| /* Fast path - we got what we asked for */ |
| if (test_and_clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)) |
| gfs2_demote_wake(gl); |
| if (state != LM_ST_UNLOCKED) { |
| if (glops->go_xmote_bh) { |
| int rv; |
| |
| spin_unlock(&gl->gl_lockref.lock); |
| rv = glops->go_xmote_bh(gl); |
| spin_lock(&gl->gl_lockref.lock); |
| if (rv) { |
| do_error(gl, rv); |
| goto out; |
| } |
| } |
| do_promote(gl); |
| } |
| out: |
| clear_bit(GLF_LOCK, &gl->gl_flags); |
| spin_unlock(&gl->gl_lockref.lock); |
| } |
| |
| static bool is_system_glock(struct gfs2_glock *gl) |
| { |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| struct gfs2_inode *m_ip = GFS2_I(sdp->sd_statfs_inode); |
| |
| if (gl == m_ip->i_gl) |
| return true; |
| return false; |
| } |
| |
| /** |
| * do_xmote - Calls the DLM to change the state of a lock |
| * @gl: The lock state |
| * @gh: The holder (only for promotes) |
| * @target: The target lock state |
| * |
| */ |
| |
| static void do_xmote(struct gfs2_glock *gl, struct gfs2_holder *gh, |
| unsigned int target) |
| __releases(&gl->gl_lockref.lock) |
| __acquires(&gl->gl_lockref.lock) |
| { |
| const struct gfs2_glock_operations *glops = gl->gl_ops; |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| unsigned int lck_flags = (unsigned int)(gh ? gh->gh_flags : 0); |
| int ret; |
| |
| if (target != LM_ST_UNLOCKED && glock_blocked_by_withdraw(gl) && |
| gh && !(gh->gh_flags & LM_FLAG_NOEXP)) |
| goto skip_inval; |
| |
| lck_flags &= (LM_FLAG_TRY | LM_FLAG_TRY_1CB | LM_FLAG_NOEXP); |
| GLOCK_BUG_ON(gl, gl->gl_state == target); |
| GLOCK_BUG_ON(gl, gl->gl_state == gl->gl_target); |
| if ((target == LM_ST_UNLOCKED || target == LM_ST_DEFERRED) && |
| glops->go_inval) { |
| /* |
| * If another process is already doing the invalidate, let that |
| * finish first. The glock state machine will get back to this |
| * holder again later. |
| */ |
| if (test_and_set_bit(GLF_INVALIDATE_IN_PROGRESS, |
| &gl->gl_flags)) |
| return; |
| do_error(gl, 0); /* Fail queued try locks */ |
| } |
| gl->gl_req = target; |
| set_bit(GLF_BLOCKING, &gl->gl_flags); |
| if ((gl->gl_req == LM_ST_UNLOCKED) || |
| (gl->gl_state == LM_ST_EXCLUSIVE) || |
| (lck_flags & (LM_FLAG_TRY|LM_FLAG_TRY_1CB))) |
| clear_bit(GLF_BLOCKING, &gl->gl_flags); |
| spin_unlock(&gl->gl_lockref.lock); |
| if (glops->go_sync) { |
| ret = glops->go_sync(gl); |
| /* If we had a problem syncing (due to io errors or whatever, |
| * we should not invalidate the metadata or tell dlm to |
| * release the glock to other nodes. |
| */ |
| if (ret) { |
| if (cmpxchg(&sdp->sd_log_error, 0, ret)) { |
| fs_err(sdp, "Error %d syncing glock \n", ret); |
| gfs2_dump_glock(NULL, gl, true); |
| } |
| goto skip_inval; |
| } |
| } |
| if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) { |
| /* |
| * The call to go_sync should have cleared out the ail list. |
| * If there are still items, we have a problem. We ought to |
| * withdraw, but we can't because the withdraw code also uses |
| * glocks. Warn about the error, dump the glock, then fall |
| * through and wait for logd to do the withdraw for us. |
| */ |
| if ((atomic_read(&gl->gl_ail_count) != 0) && |
| (!cmpxchg(&sdp->sd_log_error, 0, -EIO))) { |
| gfs2_glock_assert_warn(gl, |
| !atomic_read(&gl->gl_ail_count)); |
| gfs2_dump_glock(NULL, gl, true); |
| } |
| glops->go_inval(gl, target == LM_ST_DEFERRED ? 0 : DIO_METADATA); |
| clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); |
| } |
| |
| skip_inval: |
| gfs2_glock_hold(gl); |
| /* |
| * Check for an error encountered since we called go_sync and go_inval. |
| * If so, we can't withdraw from the glock code because the withdraw |
| * code itself uses glocks (see function signal_our_withdraw) to |
| * change the mount to read-only. Most importantly, we must not call |
| * dlm to unlock the glock until the journal is in a known good state |
| * (after journal replay) otherwise other nodes may use the object |
| * (rgrp or dinode) and then later, journal replay will corrupt the |
| * file system. The best we can do here is wait for the logd daemon |
| * to see sd_log_error and withdraw, and in the meantime, requeue the |
| * work for later. |
| * |
| * We make a special exception for some system glocks, such as the |
| * system statfs inode glock, which needs to be granted before the |
| * gfs2_quotad daemon can exit, and that exit needs to finish before |
| * we can unmount the withdrawn file system. |
| * |
| * However, if we're just unlocking the lock (say, for unmount, when |
| * gfs2_gl_hash_clear calls clear_glock) and recovery is complete |
| * then it's okay to tell dlm to unlock it. |
| */ |
| if (unlikely(sdp->sd_log_error && !gfs2_withdrawn(sdp))) |
| gfs2_withdraw_delayed(sdp); |
| if (glock_blocked_by_withdraw(gl) && |
| (target != LM_ST_UNLOCKED || |
| test_bit(SDF_WITHDRAW_RECOVERY, &sdp->sd_flags))) { |
| if (!is_system_glock(gl)) { |
| handle_callback(gl, LM_ST_UNLOCKED, 0, false); /* sets demote */ |
| /* |
| * Ordinarily, we would call dlm and its callback would call |
| * finish_xmote, which would call state_change() to the new state. |
| * Since we withdrew, we won't call dlm, so call state_change |
| * manually, but to the UNLOCKED state we desire. |
| */ |
| state_change(gl, LM_ST_UNLOCKED); |
| /* |
| * We skip telling dlm to do the locking, so we won't get a |
| * reply that would otherwise clear GLF_LOCK. So we clear it here. |
| */ |
| clear_bit(GLF_LOCK, &gl->gl_flags); |
| clear_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); |
| gfs2_glock_queue_work(gl, GL_GLOCK_DFT_HOLD); |
| goto out; |
| } else { |
| clear_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags); |
| } |
| } |
| |
| if (sdp->sd_lockstruct.ls_ops->lm_lock) { |
| /* lock_dlm */ |
| ret = sdp->sd_lockstruct.ls_ops->lm_lock(gl, target, lck_flags); |
| if (ret == -EINVAL && gl->gl_target == LM_ST_UNLOCKED && |
| target == LM_ST_UNLOCKED && |
| test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags)) { |
| finish_xmote(gl, target); |
| gfs2_glock_queue_work(gl, 0); |
| } else if (ret) { |
| fs_err(sdp, "lm_lock ret %d\n", ret); |
| GLOCK_BUG_ON(gl, !gfs2_withdrawn(sdp)); |
| } |
| } else { /* lock_nolock */ |
| finish_xmote(gl, target); |
| gfs2_glock_queue_work(gl, 0); |
| } |
| out: |
| spin_lock(&gl->gl_lockref.lock); |
| } |
| |
| /** |
| * run_queue - do all outstanding tasks related to a glock |
| * @gl: The glock in question |
| * @nonblock: True if we must not block in run_queue |
| * |
| */ |
| |
| static void run_queue(struct gfs2_glock *gl, const int nonblock) |
| __releases(&gl->gl_lockref.lock) |
| __acquires(&gl->gl_lockref.lock) |
| { |
| struct gfs2_holder *gh = NULL; |
| |
| if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) |
| return; |
| |
| GLOCK_BUG_ON(gl, test_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags)); |
| |
| if (test_bit(GLF_DEMOTE, &gl->gl_flags) && |
| gl->gl_demote_state != gl->gl_state) { |
| if (find_first_holder(gl)) |
| goto out_unlock; |
| if (nonblock) |
| goto out_sched; |
| set_bit(GLF_DEMOTE_IN_PROGRESS, &gl->gl_flags); |
| GLOCK_BUG_ON(gl, gl->gl_demote_state == LM_ST_EXCLUSIVE); |
| gl->gl_target = gl->gl_demote_state; |
| } else { |
| if (test_bit(GLF_DEMOTE, &gl->gl_flags)) |
| gfs2_demote_wake(gl); |
| if (do_promote(gl)) |
| goto out_unlock; |
| gh = find_first_waiter(gl); |
| gl->gl_target = gh->gh_state; |
| if (!(gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) |
| do_error(gl, 0); /* Fail queued try locks */ |
| } |
| do_xmote(gl, gh, gl->gl_target); |
| return; |
| |
| out_sched: |
| clear_bit(GLF_LOCK, &gl->gl_flags); |
| smp_mb__after_atomic(); |
| gl->gl_lockref.count++; |
| __gfs2_glock_queue_work(gl, 0); |
| return; |
| |
| out_unlock: |
| clear_bit(GLF_LOCK, &gl->gl_flags); |
| smp_mb__after_atomic(); |
| return; |
| } |
| |
| /** |
| * glock_set_object - set the gl_object field of a glock |
| * @gl: the glock |
| * @object: the object |
| */ |
| void glock_set_object(struct gfs2_glock *gl, void *object) |
| { |
| void *prev_object; |
| |
| spin_lock(&gl->gl_lockref.lock); |
| prev_object = gl->gl_object; |
| gl->gl_object = object; |
| spin_unlock(&gl->gl_lockref.lock); |
| if (gfs2_assert_warn(gl->gl_name.ln_sbd, prev_object == NULL)) { |
| pr_warn("glock=%u/%llx\n", |
| gl->gl_name.ln_type, |
| (unsigned long long)gl->gl_name.ln_number); |
| gfs2_dump_glock(NULL, gl, true); |
| } |
| } |
| |
| /** |
| * glock_clear_object - clear the gl_object field of a glock |
| * @gl: the glock |
| * @object: object the glock currently points at |
| */ |
| void glock_clear_object(struct gfs2_glock *gl, void *object) |
| { |
| void *prev_object; |
| |
| spin_lock(&gl->gl_lockref.lock); |
| prev_object = gl->gl_object; |
| gl->gl_object = NULL; |
| spin_unlock(&gl->gl_lockref.lock); |
| if (gfs2_assert_warn(gl->gl_name.ln_sbd, prev_object == object)) { |
| pr_warn("glock=%u/%llx\n", |
| gl->gl_name.ln_type, |
| (unsigned long long)gl->gl_name.ln_number); |
| gfs2_dump_glock(NULL, gl, true); |
| } |
| } |
| |
| void gfs2_inode_remember_delete(struct gfs2_glock *gl, u64 generation) |
| { |
| struct gfs2_inode_lvb *ri = (void *)gl->gl_lksb.sb_lvbptr; |
| |
| if (ri->ri_magic == 0) |
| ri->ri_magic = cpu_to_be32(GFS2_MAGIC); |
| if (ri->ri_magic == cpu_to_be32(GFS2_MAGIC)) |
| ri->ri_generation_deleted = cpu_to_be64(generation); |
| } |
| |
| bool gfs2_inode_already_deleted(struct gfs2_glock *gl, u64 generation) |
| { |
| struct gfs2_inode_lvb *ri = (void *)gl->gl_lksb.sb_lvbptr; |
| |
| if (ri->ri_magic != cpu_to_be32(GFS2_MAGIC)) |
| return false; |
| return generation <= be64_to_cpu(ri->ri_generation_deleted); |
| } |
| |
| static void gfs2_glock_poke(struct gfs2_glock *gl) |
| { |
| int flags = LM_FLAG_TRY_1CB | LM_FLAG_ANY | GL_SKIP; |
| struct gfs2_holder gh; |
| int error; |
| |
| __gfs2_holder_init(gl, LM_ST_SHARED, flags, &gh, _RET_IP_); |
| error = gfs2_glock_nq(&gh); |
| if (!error) |
| gfs2_glock_dq(&gh); |
| gfs2_holder_uninit(&gh); |
| } |
| |
| static bool gfs2_try_evict(struct gfs2_glock *gl) |
| { |
| struct gfs2_inode *ip; |
| bool evicted = false; |
| |
| /* |
| * If there is contention on the iopen glock and we have an inode, try |
| * to grab and release the inode so that it can be evicted. This will |
| * allow the remote node to go ahead and delete the inode without us |
| * having to do it, which will avoid rgrp glock thrashing. |
| * |
| * The remote node is likely still holding the corresponding inode |
| * glock, so it will run before we get to verify that the delete has |
| * happened below. |
| */ |
| spin_lock(&gl->gl_lockref.lock); |
| ip = gl->gl_object; |
| if (ip && !igrab(&ip->i_inode)) |
| ip = NULL; |
| spin_unlock(&gl->gl_lockref.lock); |
| if (ip) { |
| gl->gl_no_formal_ino = ip->i_no_formal_ino; |
| set_bit(GIF_DEFERRED_DELETE, &ip->i_flags); |
| d_prune_aliases(&ip->i_inode); |
| iput(&ip->i_inode); |
| |
| /* If the inode was evicted, gl->gl_object will now be NULL. */ |
| spin_lock(&gl->gl_lockref.lock); |
| ip = gl->gl_object; |
| if (ip) { |
| clear_bit(GIF_DEFERRED_DELETE, &ip->i_flags); |
| if (!igrab(&ip->i_inode)) |
| ip = NULL; |
| } |
| spin_unlock(&gl->gl_lockref.lock); |
| if (ip) { |
| gfs2_glock_poke(ip->i_gl); |
| iput(&ip->i_inode); |
| } |
| evicted = !ip; |
| } |
| return evicted; |
| } |
| |
| bool gfs2_queue_try_to_evict(struct gfs2_glock *gl) |
| { |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| |
| if (test_and_set_bit(GLF_TRY_TO_EVICT, &gl->gl_flags)) |
| return false; |
| return queue_delayed_work(sdp->sd_delete_wq, |
| &gl->gl_delete, 0); |
| } |
| |
| static bool gfs2_queue_verify_evict(struct gfs2_glock *gl) |
| { |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| |
| if (test_and_set_bit(GLF_VERIFY_EVICT, &gl->gl_flags)) |
| return false; |
| return queue_delayed_work(sdp->sd_delete_wq, |
| &gl->gl_delete, 5 * HZ); |
| } |
| |
| static void delete_work_func(struct work_struct *work) |
| { |
| struct delayed_work *dwork = to_delayed_work(work); |
| struct gfs2_glock *gl = container_of(dwork, struct gfs2_glock, gl_delete); |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| struct inode *inode; |
| u64 no_addr = gl->gl_name.ln_number; |
| |
| if (test_and_clear_bit(GLF_TRY_TO_EVICT, &gl->gl_flags)) { |
| /* |
| * If we can evict the inode, give the remote node trying to |
| * delete the inode some time before verifying that the delete |
| * has happened. Otherwise, if we cause contention on the inode glock |
| * immediately, the remote node will think that we still have |
| * the inode in use, and so it will give up waiting. |
| * |
| * If we can't evict the inode, signal to the remote node that |
| * the inode is still in use. We'll later try to delete the |
| * inode locally in gfs2_evict_inode. |
| * |
| * FIXME: We only need to verify that the remote node has |
| * deleted the inode because nodes before this remote delete |
| * rework won't cooperate. At a later time, when we no longer |
| * care about compatibility with such nodes, we can skip this |
| * step entirely. |
| */ |
| if (gfs2_try_evict(gl)) { |
| if (test_bit(SDF_KILL, &sdp->sd_flags)) |
| goto out; |
| if (gfs2_queue_verify_evict(gl)) |
| return; |
| } |
| goto out; |
| } |
| |
| if (test_and_clear_bit(GLF_VERIFY_EVICT, &gl->gl_flags)) { |
| inode = gfs2_lookup_by_inum(sdp, no_addr, gl->gl_no_formal_ino, |
| GFS2_BLKST_UNLINKED); |
| if (IS_ERR(inode)) { |
| if (PTR_ERR(inode) == -EAGAIN && |
| !test_bit(SDF_KILL, &sdp->sd_flags) && |
| gfs2_queue_verify_evict(gl)) |
| return; |
| } else { |
| d_prune_aliases(inode); |
| iput(inode); |
| } |
| } |
| |
| out: |
| gfs2_glock_put(gl); |
| } |
| |
| static void glock_work_func(struct work_struct *work) |
| { |
| unsigned long delay = 0; |
| struct gfs2_glock *gl = container_of(work, struct gfs2_glock, gl_work.work); |
| unsigned int drop_refs = 1; |
| |
| if (test_and_clear_bit(GLF_REPLY_PENDING, &gl->gl_flags)) { |
| finish_xmote(gl, gl->gl_reply); |
| drop_refs++; |
| } |
| spin_lock(&gl->gl_lockref.lock); |
| if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
| gl->gl_state != LM_ST_UNLOCKED && |
| gl->gl_demote_state != LM_ST_EXCLUSIVE) { |
| unsigned long holdtime, now = jiffies; |
| |
| holdtime = gl->gl_tchange + gl->gl_hold_time; |
| if (time_before(now, holdtime)) |
| delay = holdtime - now; |
| |
| if (!delay) { |
| clear_bit(GLF_PENDING_DEMOTE, &gl->gl_flags); |
| gfs2_set_demote(gl); |
| } |
| } |
| run_queue(gl, 0); |
| if (delay) { |
| /* Keep one glock reference for the work we requeue. */ |
| drop_refs--; |
| if (gl->gl_name.ln_type != LM_TYPE_INODE) |
| delay = 0; |
| __gfs2_glock_queue_work(gl, delay); |
| } |
| |
| /* |
| * Drop the remaining glock references manually here. (Mind that |
| * __gfs2_glock_queue_work depends on the lockref spinlock begin held |
| * here as well.) |
| */ |
| gl->gl_lockref.count -= drop_refs; |
| if (!gl->gl_lockref.count) { |
| __gfs2_glock_put(gl); |
| return; |
| } |
| spin_unlock(&gl->gl_lockref.lock); |
| } |
| |
| static struct gfs2_glock *find_insert_glock(struct lm_lockname *name, |
| struct gfs2_glock *new) |
| { |
| struct wait_glock_queue wait; |
| wait_queue_head_t *wq = glock_waitqueue(name); |
| struct gfs2_glock *gl; |
| |
| wait.name = name; |
| init_wait(&wait.wait); |
| wait.wait.func = glock_wake_function; |
| |
| again: |
| prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); |
| rcu_read_lock(); |
| if (new) { |
| gl = rhashtable_lookup_get_insert_fast(&gl_hash_table, |
| &new->gl_node, ht_parms); |
| if (IS_ERR(gl)) |
| goto out; |
| } else { |
| gl = rhashtable_lookup_fast(&gl_hash_table, |
| name, ht_parms); |
| } |
| if (gl && !lockref_get_not_dead(&gl->gl_lockref)) { |
| rcu_read_unlock(); |
| schedule(); |
| goto again; |
| } |
| out: |
| rcu_read_unlock(); |
| finish_wait(wq, &wait.wait); |
| return gl; |
| } |
| |
| /** |
| * gfs2_glock_get() - Get a glock, or create one if one doesn't exist |
| * @sdp: The GFS2 superblock |
| * @number: the lock number |
| * @glops: The glock_operations to use |
| * @create: If 0, don't create the glock if it doesn't exist |
| * @glp: the glock is returned here |
| * |
| * This does not lock a glock, just finds/creates structures for one. |
| * |
| * Returns: errno |
| */ |
| |
| int gfs2_glock_get(struct gfs2_sbd *sdp, u64 number, |
| const struct gfs2_glock_operations *glops, int create, |
| struct gfs2_glock **glp) |
| { |
| struct super_block *s = sdp->sd_vfs; |
| struct lm_lockname name = { .ln_number = number, |
| .ln_type = glops->go_type, |
| .ln_sbd = sdp }; |
| struct gfs2_glock *gl, *tmp; |
| struct address_space *mapping; |
| int ret = 0; |
| |
| gl = find_insert_glock(&name, NULL); |
| if (gl) { |
| *glp = gl; |
| return 0; |
| } |
| if (!create) |
| return -ENOENT; |
| |
| if (glops->go_flags & GLOF_ASPACE) { |
| struct gfs2_glock_aspace *gla = |
| kmem_cache_alloc(gfs2_glock_aspace_cachep, GFP_NOFS); |
| if (!gla) |
| return -ENOMEM; |
| gl = &gla->glock; |
| } else { |
| gl = kmem_cache_alloc(gfs2_glock_cachep, GFP_NOFS); |
| if (!gl) |
| return -ENOMEM; |
| } |
| memset(&gl->gl_lksb, 0, sizeof(struct dlm_lksb)); |
| gl->gl_ops = glops; |
| |
| if (glops->go_flags & GLOF_LVB) { |
| gl->gl_lksb.sb_lvbptr = kzalloc(GDLM_LVB_SIZE, GFP_NOFS); |
| if (!gl->gl_lksb.sb_lvbptr) { |
| gfs2_glock_dealloc(&gl->gl_rcu); |
| return -ENOMEM; |
| } |
| } |
| |
| atomic_inc(&sdp->sd_glock_disposal); |
| gl->gl_node.next = NULL; |
| gl->gl_flags = glops->go_instantiate ? BIT(GLF_INSTANTIATE_NEEDED) : 0; |
| gl->gl_name = name; |
| lockdep_set_subclass(&gl->gl_lockref.lock, glops->go_subclass); |
| gl->gl_lockref.count = 1; |
| gl->gl_state = LM_ST_UNLOCKED; |
| gl->gl_target = LM_ST_UNLOCKED; |
| gl->gl_demote_state = LM_ST_EXCLUSIVE; |
| gl->gl_dstamp = 0; |
| preempt_disable(); |
| /* We use the global stats to estimate the initial per-glock stats */ |
| gl->gl_stats = this_cpu_ptr(sdp->sd_lkstats)->lkstats[glops->go_type]; |
| preempt_enable(); |
| gl->gl_stats.stats[GFS2_LKS_DCOUNT] = 0; |
| gl->gl_stats.stats[GFS2_LKS_QCOUNT] = 0; |
| gl->gl_tchange = jiffies; |
| gl->gl_object = NULL; |
| gl->gl_hold_time = GL_GLOCK_DFT_HOLD; |
| INIT_DELAYED_WORK(&gl->gl_work, glock_work_func); |
| if (gl->gl_name.ln_type == LM_TYPE_IOPEN) |
| INIT_DELAYED_WORK(&gl->gl_delete, delete_work_func); |
| |
| mapping = gfs2_glock2aspace(gl); |
| if (mapping) { |
| mapping->a_ops = &gfs2_meta_aops; |
| mapping->host = s->s_bdev->bd_inode; |
| mapping->flags = 0; |
| mapping_set_gfp_mask(mapping, GFP_NOFS); |
| mapping->private_data = NULL; |
| mapping->writeback_index = 0; |
| } |
| |
| tmp = find_insert_glock(&name, gl); |
| if (!tmp) { |
| *glp = gl; |
| goto out; |
| } |
| if (IS_ERR(tmp)) { |
| ret = PTR_ERR(tmp); |
| goto out_free; |
| } |
| *glp = tmp; |
| |
| out_free: |
| gfs2_glock_dealloc(&gl->gl_rcu); |
| if (atomic_dec_and_test(&sdp->sd_glock_disposal)) |
| wake_up(&sdp->sd_kill_wait); |
| |
| out: |
| return ret; |
| } |
| |
| /** |
| * __gfs2_holder_init - initialize a struct gfs2_holder in the default way |
| * @gl: the glock |
| * @state: the state we're requesting |
| * @flags: the modifier flags |
| * @gh: the holder structure |
| * |
| */ |
| |
| void __gfs2_holder_init(struct gfs2_glock *gl, unsigned int state, u16 flags, |
| struct gfs2_holder *gh, unsigned long ip) |
| { |
| INIT_LIST_HEAD(&gh->gh_list); |
| gh->gh_gl = gfs2_glock_hold(gl); |
| gh->gh_ip = ip; |
| gh->gh_owner_pid = get_pid(task_pid(current)); |
| gh->gh_state = state; |
| gh->gh_flags = flags; |
| gh->gh_iflags = 0; |
| } |
| |
| /** |
| * gfs2_holder_reinit - reinitialize a struct gfs2_holder so we can requeue it |
| * @state: the state we're requesting |
| * @flags: the modifier flags |
| * @gh: the holder structure |
| * |
| * Don't mess with the glock. |
| * |
| */ |
| |
| void gfs2_holder_reinit(unsigned int state, u16 flags, struct gfs2_holder *gh) |
| { |
| gh->gh_state = state; |
| gh->gh_flags = flags; |
| gh->gh_iflags = 0; |
| gh->gh_ip = _RET_IP_; |
| put_pid(gh->gh_owner_pid); |
| gh->gh_owner_pid = get_pid(task_pid(current)); |
| } |
| |
| /** |
| * gfs2_holder_uninit - uninitialize a holder structure (drop glock reference) |
| * @gh: the holder structure |
| * |
| */ |
| |
| void gfs2_holder_uninit(struct gfs2_holder *gh) |
| { |
| put_pid(gh->gh_owner_pid); |
| gfs2_glock_put(gh->gh_gl); |
| gfs2_holder_mark_uninitialized(gh); |
| gh->gh_ip = 0; |
| } |
| |
| static void gfs2_glock_update_hold_time(struct gfs2_glock *gl, |
| unsigned long start_time) |
| { |
| /* Have we waited longer that a second? */ |
| if (time_after(jiffies, start_time + HZ)) { |
| /* Lengthen the minimum hold time. */ |
| gl->gl_hold_time = min(gl->gl_hold_time + GL_GLOCK_HOLD_INCR, |
| GL_GLOCK_MAX_HOLD); |
| } |
| } |
| |
| /** |
| * gfs2_glock_holder_ready - holder is ready and its error code can be collected |
| * @gh: the glock holder |
| * |
| * Called when a glock holder no longer needs to be waited for because it is |
| * now either held (HIF_HOLDER set; gh_error == 0), or acquiring the lock has |
| * failed (gh_error != 0). |
| */ |
| |
| int gfs2_glock_holder_ready(struct gfs2_holder *gh) |
| { |
| if (gh->gh_error || (gh->gh_flags & GL_SKIP)) |
| return gh->gh_error; |
| gh->gh_error = gfs2_instantiate(gh); |
| if (gh->gh_error) |
| gfs2_glock_dq(gh); |
| return gh->gh_error; |
| } |
| |
| /** |
| * gfs2_glock_wait - wait on a glock acquisition |
| * @gh: the glock holder |
| * |
| * Returns: 0 on success |
| */ |
| |
| int gfs2_glock_wait(struct gfs2_holder *gh) |
| { |
| unsigned long start_time = jiffies; |
| |
| might_sleep(); |
| wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE); |
| gfs2_glock_update_hold_time(gh->gh_gl, start_time); |
| return gfs2_glock_holder_ready(gh); |
| } |
| |
| static int glocks_pending(unsigned int num_gh, struct gfs2_holder *ghs) |
| { |
| int i; |
| |
| for (i = 0; i < num_gh; i++) |
| if (test_bit(HIF_WAIT, &ghs[i].gh_iflags)) |
| return 1; |
| return 0; |
| } |
| |
| /** |
| * gfs2_glock_async_wait - wait on multiple asynchronous glock acquisitions |
| * @num_gh: the number of holders in the array |
| * @ghs: the glock holder array |
| * |
| * Returns: 0 on success, meaning all glocks have been granted and are held. |
| * -ESTALE if the request timed out, meaning all glocks were released, |
| * and the caller should retry the operation. |
| */ |
| |
| int gfs2_glock_async_wait(unsigned int num_gh, struct gfs2_holder *ghs) |
| { |
| struct gfs2_sbd *sdp = ghs[0].gh_gl->gl_name.ln_sbd; |
| int i, ret = 0, timeout = 0; |
| unsigned long start_time = jiffies; |
| |
| might_sleep(); |
| /* |
| * Total up the (minimum hold time * 2) of all glocks and use that to |
| * determine the max amount of time we should wait. |
| */ |
| for (i = 0; i < num_gh; i++) |
| timeout += ghs[i].gh_gl->gl_hold_time << 1; |
| |
| if (!wait_event_timeout(sdp->sd_async_glock_wait, |
| !glocks_pending(num_gh, ghs), timeout)) { |
| ret = -ESTALE; /* request timed out. */ |
| goto out; |
| } |
| |
| for (i = 0; i < num_gh; i++) { |
| struct gfs2_holder *gh = &ghs[i]; |
| int ret2; |
| |
| if (test_bit(HIF_HOLDER, &gh->gh_iflags)) { |
| gfs2_glock_update_hold_time(gh->gh_gl, |
| start_time); |
| } |
| ret2 = gfs2_glock_holder_ready(gh); |
| if (!ret) |
| ret = ret2; |
| } |
| |
| out: |
| if (ret) { |
| for (i = 0; i < num_gh; i++) { |
| struct gfs2_holder *gh = &ghs[i]; |
| |
| gfs2_glock_dq(gh); |
| } |
| } |
| return ret; |
| } |
| |
| /** |
| * handle_callback - process a demote request |
| * @gl: the glock |
| * @state: the state the caller wants us to change to |
| * @delay: zero to demote immediately; otherwise pending demote |
| * @remote: true if this came from a different cluster node |
| * |
| * There are only two requests that we are going to see in actual |
| * practise: LM_ST_SHARED and LM_ST_UNLOCKED |
| */ |
| |
| static void handle_callback(struct gfs2_glock *gl, unsigned int state, |
| unsigned long delay, bool remote) |
| { |
| if (delay) |
| set_bit(GLF_PENDING_DEMOTE, &gl->gl_flags); |
| else |
| gfs2_set_demote(gl); |
| if (gl->gl_demote_state == LM_ST_EXCLUSIVE) { |
| gl->gl_demote_state = state; |
| gl->gl_demote_time = jiffies; |
| } else if (gl->gl_demote_state != LM_ST_UNLOCKED && |
| gl->gl_demote_state != state) { |
| gl->gl_demote_state = LM_ST_UNLOCKED; |
| } |
| if (gl->gl_ops->go_callback) |
| gl->gl_ops->go_callback(gl, remote); |
| trace_gfs2_demote_rq(gl, remote); |
| } |
| |
| void gfs2_print_dbg(struct seq_file *seq, const char *fmt, ...) |
| { |
| struct va_format vaf; |
| va_list args; |
| |
| va_start(args, fmt); |
| |
| if (seq) { |
| seq_vprintf(seq, fmt, args); |
| } else { |
| vaf.fmt = fmt; |
| vaf.va = &args; |
| |
| pr_err("%pV", &vaf); |
| } |
| |
| va_end(args); |
| } |
| |
| static inline bool pid_is_meaningful(const struct gfs2_holder *gh) |
| { |
| if (!(gh->gh_flags & GL_NOPID)) |
| return true; |
| if (gh->gh_state == LM_ST_UNLOCKED) |
| return true; |
| return false; |
| } |
| |
| /** |
| * add_to_queue - Add a holder to the wait queue (but look for recursion) |
| * @gh: the holder structure to add |
| * |
| * Eventually we should move the recursive locking trap to a |
| * debugging option or something like that. This is the fast |
| * path and needs to have the minimum number of distractions. |
| * |
| */ |
| |
| static inline void add_to_queue(struct gfs2_holder *gh) |
| __releases(&gl->gl_lockref.lock) |
| __acquires(&gl->gl_lockref.lock) |
| { |
| struct gfs2_glock *gl = gh->gh_gl; |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| struct list_head *insert_pt = NULL; |
| struct gfs2_holder *gh2; |
| int try_futile = 0; |
| |
| GLOCK_BUG_ON(gl, gh->gh_owner_pid == NULL); |
| if (test_and_set_bit(HIF_WAIT, &gh->gh_iflags)) |
| GLOCK_BUG_ON(gl, true); |
| |
| if (gh->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB)) { |
| if (test_bit(GLF_LOCK, &gl->gl_flags)) { |
| struct gfs2_holder *current_gh; |
| |
| current_gh = find_first_holder(gl); |
| try_futile = !may_grant(gl, current_gh, gh); |
| } |
| if (test_bit(GLF_INVALIDATE_IN_PROGRESS, &gl->gl_flags)) |
| goto fail; |
| } |
| |
| list_for_each_entry(gh2, &gl->gl_holders, gh_list) { |
| if (likely(gh2->gh_owner_pid != gh->gh_owner_pid)) |
| continue; |
| if (gh->gh_gl->gl_ops->go_type == LM_TYPE_FLOCK) |
| continue; |
| if (!pid_is_meaningful(gh2)) |
| continue; |
| goto trap_recursive; |
| } |
| list_for_each_entry(gh2, &gl->gl_holders, gh_list) { |
| if (try_futile && |
| !(gh2->gh_flags & (LM_FLAG_TRY | LM_FLAG_TRY_1CB))) { |
| fail: |
| gh->gh_error = GLR_TRYFAILED; |
| gfs2_holder_wake(gh); |
| return; |
| } |
| if (test_bit(HIF_HOLDER, &gh2->gh_iflags)) |
| continue; |
| } |
| trace_gfs2_glock_queue(gh, 1); |
| gfs2_glstats_inc(gl, GFS2_LKS_QCOUNT); |
| gfs2_sbstats_inc(gl, GFS2_LKS_QCOUNT); |
| if (likely(insert_pt == NULL)) { |
| list_add_tail(&gh->gh_list, &gl->gl_holders); |
| return; |
| } |
| list_add_tail(&gh->gh_list, insert_pt); |
| gh = list_first_entry(&gl->gl_holders, struct gfs2_holder, gh_list); |
| spin_unlock(&gl->gl_lockref.lock); |
| if (sdp->sd_lockstruct.ls_ops->lm_cancel) |
| sdp->sd_lockstruct.ls_ops->lm_cancel(gl); |
| spin_lock(&gl->gl_lockref.lock); |
| return; |
| |
| trap_recursive: |
| fs_err(sdp, "original: %pSR\n", (void *)gh2->gh_ip); |
| fs_err(sdp, "pid: %d\n", pid_nr(gh2->gh_owner_pid)); |
| fs_err(sdp, "lock type: %d req lock state : %d\n", |
| gh2->gh_gl->gl_name.ln_type, gh2->gh_state); |
| fs_err(sdp, "new: %pSR\n", (void *)gh->gh_ip); |
| fs_err(sdp, "pid: %d\n", pid_nr(gh->gh_owner_pid)); |
| fs_err(sdp, "lock type: %d req lock state : %d\n", |
| gh->gh_gl->gl_name.ln_type, gh->gh_state); |
| gfs2_dump_glock(NULL, gl, true); |
| BUG(); |
| } |
| |
| /** |
| * gfs2_glock_nq - enqueue a struct gfs2_holder onto a glock (acquire a glock) |
| * @gh: the holder structure |
| * |
| * if (gh->gh_flags & GL_ASYNC), this never returns an error |
| * |
| * Returns: 0, GLR_TRYFAILED, or errno on failure |
| */ |
| |
| int gfs2_glock_nq(struct gfs2_holder *gh) |
| { |
| struct gfs2_glock *gl = gh->gh_gl; |
| int error = 0; |
| |
| if (glock_blocked_by_withdraw(gl) && !(gh->gh_flags & LM_FLAG_NOEXP)) |
| return -EIO; |
| |
| if (test_bit(GLF_LRU, &gl->gl_flags)) |
| gfs2_glock_remove_from_lru(gl); |
| |
| gh->gh_error = 0; |
| spin_lock(&gl->gl_lockref.lock); |
| add_to_queue(gh); |
| if (unlikely((LM_FLAG_NOEXP & gh->gh_flags) && |
| test_and_clear_bit(GLF_FROZEN, &gl->gl_flags))) { |
| set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
| gl->gl_lockref.count++; |
| __gfs2_glock_queue_work(gl, 0); |
| } |
| run_queue(gl, 1); |
| spin_unlock(&gl->gl_lockref.lock); |
| |
| if (!(gh->gh_flags & GL_ASYNC)) |
| error = gfs2_glock_wait(gh); |
| |
| return error; |
| } |
| |
| /** |
| * gfs2_glock_poll - poll to see if an async request has been completed |
| * @gh: the holder |
| * |
| * Returns: 1 if the request is ready to be gfs2_glock_wait()ed on |
| */ |
| |
| int gfs2_glock_poll(struct gfs2_holder *gh) |
| { |
| return test_bit(HIF_WAIT, &gh->gh_iflags) ? 0 : 1; |
| } |
| |
| static inline bool needs_demote(struct gfs2_glock *gl) |
| { |
| return (test_bit(GLF_DEMOTE, &gl->gl_flags) || |
| test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags)); |
| } |
| |
| static void __gfs2_glock_dq(struct gfs2_holder *gh) |
| { |
| struct gfs2_glock *gl = gh->gh_gl; |
| unsigned delay = 0; |
| int fast_path = 0; |
| |
| /* |
| * This holder should not be cached, so mark it for demote. |
| * Note: this should be done before the check for needs_demote |
| * below. |
| */ |
| if (gh->gh_flags & GL_NOCACHE) |
| handle_callback(gl, LM_ST_UNLOCKED, 0, false); |
| |
| list_del_init(&gh->gh_list); |
| clear_bit(HIF_HOLDER, &gh->gh_iflags); |
| trace_gfs2_glock_queue(gh, 0); |
| |
| /* |
| * If there hasn't been a demote request we are done. |
| * (Let the remaining holders, if any, keep holding it.) |
| */ |
| if (!needs_demote(gl)) { |
| if (list_empty(&gl->gl_holders)) |
| fast_path = 1; |
| } |
| |
| if (!test_bit(GLF_LFLUSH, &gl->gl_flags) && demote_ok(gl)) |
| gfs2_glock_add_to_lru(gl); |
| |
| if (unlikely(!fast_path)) { |
| gl->gl_lockref.count++; |
| if (test_bit(GLF_PENDING_DEMOTE, &gl->gl_flags) && |
| !test_bit(GLF_DEMOTE, &gl->gl_flags) && |
| gl->gl_name.ln_type == LM_TYPE_INODE) |
| delay = gl->gl_hold_time; |
| __gfs2_glock_queue_work(gl, delay); |
| } |
| } |
| |
| /** |
| * gfs2_glock_dq - dequeue a struct gfs2_holder from a glock (release a glock) |
| * @gh: the glock holder |
| * |
| */ |
| void gfs2_glock_dq(struct gfs2_holder *gh) |
| { |
| struct gfs2_glock *gl = gh->gh_gl; |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| |
| spin_lock(&gl->gl_lockref.lock); |
| if (!gfs2_holder_queued(gh)) { |
| /* |
| * May have already been dequeued because the locking request |
| * was GL_ASYNC and it has failed in the meantime. |
| */ |
| goto out; |
| } |
| |
| if (list_is_first(&gh->gh_list, &gl->gl_holders) && |
| !test_bit(HIF_HOLDER, &gh->gh_iflags)) { |
| spin_unlock(&gl->gl_lockref.lock); |
| gl->gl_name.ln_sbd->sd_lockstruct.ls_ops->lm_cancel(gl); |
| wait_on_bit(&gh->gh_iflags, HIF_WAIT, TASK_UNINTERRUPTIBLE); |
| spin_lock(&gl->gl_lockref.lock); |
| } |
| |
| /* |
| * If we're in the process of file system withdraw, we cannot just |
| * dequeue any glocks until our journal is recovered, lest we introduce |
| * file system corruption. We need two exceptions to this rule: We need |
| * to allow unlocking of nondisk glocks and the glock for our own |
| * journal that needs recovery. |
| */ |
| if (test_bit(SDF_WITHDRAW_RECOVERY, &sdp->sd_flags) && |
| glock_blocked_by_withdraw(gl) && |
| gh->gh_gl != sdp->sd_jinode_gl) { |
| sdp->sd_glock_dqs_held++; |
| spin_unlock(&gl->gl_lockref.lock); |
| might_sleep(); |
| wait_on_bit(&sdp->sd_flags, SDF_WITHDRAW_RECOVERY, |
| TASK_UNINTERRUPTIBLE); |
| spin_lock(&gl->gl_lockref.lock); |
| } |
| |
| __gfs2_glock_dq(gh); |
| out: |
| spin_unlock(&gl->gl_lockref.lock); |
| } |
| |
| void gfs2_glock_dq_wait(struct gfs2_holder *gh) |
| { |
| struct gfs2_glock *gl = gh->gh_gl; |
| gfs2_glock_dq(gh); |
| might_sleep(); |
| wait_on_bit(&gl->gl_flags, GLF_DEMOTE, TASK_UNINTERRUPTIBLE); |
| } |
| |
| /** |
| * gfs2_glock_dq_uninit - dequeue a holder from a glock and initialize it |
| * @gh: the holder structure |
| * |
| */ |
| |
| void gfs2_glock_dq_uninit(struct gfs2_holder *gh) |
| { |
| gfs2_glock_dq(gh); |
| gfs2_holder_uninit(gh); |
| } |
| |
| /** |
| * gfs2_glock_nq_num - acquire a glock based on lock number |
| * @sdp: the filesystem |
| * @number: the lock number |
| * @glops: the glock operations for the type of glock |
| * @state: the state to acquire the glock in |
| * @flags: modifier flags for the acquisition |
| * @gh: the struct gfs2_holder |
| * |
| * Returns: errno |
| */ |
| |
| int gfs2_glock_nq_num(struct gfs2_sbd *sdp, u64 number, |
| const struct gfs2_glock_operations *glops, |
| unsigned int state, u16 flags, struct gfs2_holder *gh) |
| { |
| struct gfs2_glock *gl; |
| int error; |
| |
| error = gfs2_glock_get(sdp, number, glops, CREATE, &gl); |
| if (!error) { |
| error = gfs2_glock_nq_init(gl, state, flags, gh); |
| gfs2_glock_put(gl); |
| } |
| |
| return error; |
| } |
| |
| /** |
| * glock_compare - Compare two struct gfs2_glock structures for sorting |
| * @arg_a: the first structure |
| * @arg_b: the second structure |
| * |
| */ |
| |
| static int glock_compare(const void *arg_a, const void *arg_b) |
| { |
| const struct gfs2_holder *gh_a = *(const struct gfs2_holder **)arg_a; |
| const struct gfs2_holder *gh_b = *(const struct gfs2_holder **)arg_b; |
| const struct lm_lockname *a = &gh_a->gh_gl->gl_name; |
| const struct lm_lockname *b = &gh_b->gh_gl->gl_name; |
| |
| if (a->ln_number > b->ln_number) |
| return 1; |
| if (a->ln_number < b->ln_number) |
| return -1; |
| BUG_ON(gh_a->gh_gl->gl_ops->go_type == gh_b->gh_gl->gl_ops->go_type); |
| return 0; |
| } |
| |
| /** |
| * nq_m_sync - synchronously acquire more than one glock in deadlock free order |
| * @num_gh: the number of structures |
| * @ghs: an array of struct gfs2_holder structures |
| * @p: placeholder for the holder structure to pass back |
| * |
| * Returns: 0 on success (all glocks acquired), |
| * errno on failure (no glocks acquired) |
| */ |
| |
| static int nq_m_sync(unsigned int num_gh, struct gfs2_holder *ghs, |
| struct gfs2_holder **p) |
| { |
| unsigned int x; |
| int error = 0; |
| |
| for (x = 0; x < num_gh; x++) |
| p[x] = &ghs[x]; |
| |
| sort(p, num_gh, sizeof(struct gfs2_holder *), glock_compare, NULL); |
| |
| for (x = 0; x < num_gh; x++) { |
| error = gfs2_glock_nq(p[x]); |
| if (error) { |
| while (x--) |
| gfs2_glock_dq(p[x]); |
| break; |
| } |
| } |
| |
| return error; |
| } |
| |
| /** |
| * gfs2_glock_nq_m - acquire multiple glocks |
| * @num_gh: the number of structures |
| * @ghs: an array of struct gfs2_holder structures |
| * |
| * Returns: 0 on success (all glocks acquired), |
| * errno on failure (no glocks acquired) |
| */ |
| |
| int gfs2_glock_nq_m(unsigned int num_gh, struct gfs2_holder *ghs) |
| { |
| struct gfs2_holder *tmp[4]; |
| struct gfs2_holder **pph = tmp; |
| int error = 0; |
| |
| switch(num_gh) { |
| case 0: |
| return 0; |
| case 1: |
| return gfs2_glock_nq(ghs); |
| default: |
| if (num_gh <= 4) |
| break; |
| pph = kmalloc_array(num_gh, sizeof(struct gfs2_holder *), |
| GFP_NOFS); |
| if (!pph) |
| return -ENOMEM; |
| } |
| |
| error = nq_m_sync(num_gh, ghs, pph); |
| |
| if (pph != tmp) |
| kfree(pph); |
| |
| return error; |
| } |
| |
| /** |
| * gfs2_glock_dq_m - release multiple glocks |
| * @num_gh: the number of structures |
| * @ghs: an array of struct gfs2_holder structures |
| * |
| */ |
| |
| void gfs2_glock_dq_m(unsigned int num_gh, struct gfs2_holder *ghs) |
| { |
| while (num_gh--) |
| gfs2_glock_dq(&ghs[num_gh]); |
| } |
| |
| void gfs2_glock_cb(struct gfs2_glock *gl, unsigned int state) |
| { |
| unsigned long delay = 0; |
| unsigned long holdtime; |
| unsigned long now = jiffies; |
| |
| gfs2_glock_hold(gl); |
| spin_lock(&gl->gl_lockref.lock); |
| holdtime = gl->gl_tchange + gl->gl_hold_time; |
| if (!list_empty(&gl->gl_holders) && |
| gl->gl_name.ln_type == LM_TYPE_INODE) { |
| if (time_before(now, holdtime)) |
| delay = holdtime - now; |
| if (test_bit(GLF_REPLY_PENDING, &gl->gl_flags)) |
| delay = gl->gl_hold_time; |
| } |
| handle_callback(gl, state, delay, true); |
| __gfs2_glock_queue_work(gl, delay); |
| spin_unlock(&gl->gl_lockref.lock); |
| } |
| |
| /** |
| * gfs2_should_freeze - Figure out if glock should be frozen |
| * @gl: The glock in question |
| * |
| * Glocks are not frozen if (a) the result of the dlm operation is |
| * an error, (b) the locking operation was an unlock operation or |
| * (c) if there is a "noexp" flagged request anywhere in the queue |
| * |
| * Returns: 1 if freezing should occur, 0 otherwise |
| */ |
| |
| static int gfs2_should_freeze(const struct gfs2_glock *gl) |
| { |
| const struct gfs2_holder *gh; |
| |
| if (gl->gl_reply & ~LM_OUT_ST_MASK) |
| return 0; |
| if (gl->gl_target == LM_ST_UNLOCKED) |
| return 0; |
| |
| list_for_each_entry(gh, &gl->gl_holders, gh_list) { |
| if (test_bit(HIF_HOLDER, &gh->gh_iflags)) |
| continue; |
| if (LM_FLAG_NOEXP & gh->gh_flags) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| /** |
| * gfs2_glock_complete - Callback used by locking |
| * @gl: Pointer to the glock |
| * @ret: The return value from the dlm |
| * |
| * The gl_reply field is under the gl_lockref.lock lock so that it is ok |
| * to use a bitfield shared with other glock state fields. |
| */ |
| |
| void gfs2_glock_complete(struct gfs2_glock *gl, int ret) |
| { |
| struct lm_lockstruct *ls = &gl->gl_name.ln_sbd->sd_lockstruct; |
| |
| spin_lock(&gl->gl_lockref.lock); |
| gl->gl_reply = ret; |
| |
| if (unlikely(test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags))) { |
| if (gfs2_should_freeze(gl)) { |
| set_bit(GLF_FROZEN, &gl->gl_flags); |
| spin_unlock(&gl->gl_lockref.lock); |
| return; |
| } |
| } |
| |
| gl->gl_lockref.count++; |
| set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
| __gfs2_glock_queue_work(gl, 0); |
| spin_unlock(&gl->gl_lockref.lock); |
| } |
| |
| static int glock_cmp(void *priv, const struct list_head *a, |
| const struct list_head *b) |
| { |
| struct gfs2_glock *gla, *glb; |
| |
| gla = list_entry(a, struct gfs2_glock, gl_lru); |
| glb = list_entry(b, struct gfs2_glock, gl_lru); |
| |
| if (gla->gl_name.ln_number > glb->gl_name.ln_number) |
| return 1; |
| if (gla->gl_name.ln_number < glb->gl_name.ln_number) |
| return -1; |
| |
| return 0; |
| } |
| |
| /** |
| * gfs2_dispose_glock_lru - Demote a list of glocks |
| * @list: The list to dispose of |
| * |
| * Disposing of glocks may involve disk accesses, so that here we sort |
| * the glocks by number (i.e. disk location of the inodes) so that if |
| * there are any such accesses, they'll be sent in order (mostly). |
| * |
| * Must be called under the lru_lock, but may drop and retake this |
| * lock. While the lru_lock is dropped, entries may vanish from the |
| * list, but no new entries will appear on the list (since it is |
| * private) |
| */ |
| |
| static void gfs2_dispose_glock_lru(struct list_head *list) |
| __releases(&lru_lock) |
| __acquires(&lru_lock) |
| { |
| struct gfs2_glock *gl; |
| |
| list_sort(NULL, list, glock_cmp); |
| |
| while(!list_empty(list)) { |
| gl = list_first_entry(list, struct gfs2_glock, gl_lru); |
| list_del_init(&gl->gl_lru); |
| clear_bit(GLF_LRU, &gl->gl_flags); |
| if (!spin_trylock(&gl->gl_lockref.lock)) { |
| add_back_to_lru: |
| list_add(&gl->gl_lru, &lru_list); |
| set_bit(GLF_LRU, &gl->gl_flags); |
| atomic_inc(&lru_count); |
| continue; |
| } |
| if (test_and_set_bit(GLF_LOCK, &gl->gl_flags)) { |
| spin_unlock(&gl->gl_lockref.lock); |
| goto add_back_to_lru; |
| } |
| gl->gl_lockref.count++; |
| if (demote_ok(gl)) |
| handle_callback(gl, LM_ST_UNLOCKED, 0, false); |
| WARN_ON(!test_and_clear_bit(GLF_LOCK, &gl->gl_flags)); |
| __gfs2_glock_queue_work(gl, 0); |
| spin_unlock(&gl->gl_lockref.lock); |
| cond_resched_lock(&lru_lock); |
| } |
| } |
| |
| /** |
| * gfs2_scan_glock_lru - Scan the LRU looking for locks to demote |
| * @nr: The number of entries to scan |
| * |
| * This function selects the entries on the LRU which are able to |
| * be demoted, and then kicks off the process by calling |
| * gfs2_dispose_glock_lru() above. |
| */ |
| |
| static long gfs2_scan_glock_lru(int nr) |
| { |
| struct gfs2_glock *gl, *next; |
| LIST_HEAD(dispose); |
| long freed = 0; |
| |
| spin_lock(&lru_lock); |
| list_for_each_entry_safe(gl, next, &lru_list, gl_lru) { |
| if (nr-- <= 0) |
| break; |
| /* Test for being demotable */ |
| if (!test_bit(GLF_LOCK, &gl->gl_flags)) { |
| if (!spin_trylock(&gl->gl_lockref.lock)) |
| continue; |
| if (gl->gl_lockref.count <= 1 && |
| (gl->gl_state == LM_ST_UNLOCKED || |
| demote_ok(gl))) { |
| list_move(&gl->gl_lru, &dispose); |
| atomic_dec(&lru_count); |
| freed++; |
| } |
| spin_unlock(&gl->gl_lockref.lock); |
| } |
| } |
| if (!list_empty(&dispose)) |
| gfs2_dispose_glock_lru(&dispose); |
| spin_unlock(&lru_lock); |
| |
| return freed; |
| } |
| |
| static unsigned long gfs2_glock_shrink_scan(struct shrinker *shrink, |
| struct shrink_control *sc) |
| { |
| if (!(sc->gfp_mask & __GFP_FS)) |
| return SHRINK_STOP; |
| return gfs2_scan_glock_lru(sc->nr_to_scan); |
| } |
| |
| static unsigned long gfs2_glock_shrink_count(struct shrinker *shrink, |
| struct shrink_control *sc) |
| { |
| return vfs_pressure_ratio(atomic_read(&lru_count)); |
| } |
| |
| static struct shrinker glock_shrinker = { |
| .seeks = DEFAULT_SEEKS, |
| .count_objects = gfs2_glock_shrink_count, |
| .scan_objects = gfs2_glock_shrink_scan, |
| }; |
| |
| /** |
| * glock_hash_walk - Call a function for glock in a hash bucket |
| * @examiner: the function |
| * @sdp: the filesystem |
| * |
| * Note that the function can be called multiple times on the same |
| * object. So the user must ensure that the function can cope with |
| * that. |
| */ |
| |
| static void glock_hash_walk(glock_examiner examiner, const struct gfs2_sbd *sdp) |
| { |
| struct gfs2_glock *gl; |
| struct rhashtable_iter iter; |
| |
| rhashtable_walk_enter(&gl_hash_table, &iter); |
| |
| do { |
| rhashtable_walk_start(&iter); |
| |
| while ((gl = rhashtable_walk_next(&iter)) && !IS_ERR(gl)) { |
| if (gl->gl_name.ln_sbd == sdp) |
| examiner(gl); |
| } |
| |
| rhashtable_walk_stop(&iter); |
| } while (cond_resched(), gl == ERR_PTR(-EAGAIN)); |
| |
| rhashtable_walk_exit(&iter); |
| } |
| |
| void gfs2_cancel_delete_work(struct gfs2_glock *gl) |
| { |
| clear_bit(GLF_TRY_TO_EVICT, &gl->gl_flags); |
| clear_bit(GLF_VERIFY_EVICT, &gl->gl_flags); |
| if (cancel_delayed_work(&gl->gl_delete)) |
| gfs2_glock_put(gl); |
| } |
| |
| static void flush_delete_work(struct gfs2_glock *gl) |
| { |
| if (gl->gl_name.ln_type == LM_TYPE_IOPEN) { |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| |
| if (cancel_delayed_work(&gl->gl_delete)) { |
| queue_delayed_work(sdp->sd_delete_wq, |
| &gl->gl_delete, 0); |
| } |
| } |
| } |
| |
| void gfs2_flush_delete_work(struct gfs2_sbd *sdp) |
| { |
| glock_hash_walk(flush_delete_work, sdp); |
| flush_workqueue(sdp->sd_delete_wq); |
| } |
| |
| /** |
| * thaw_glock - thaw out a glock which has an unprocessed reply waiting |
| * @gl: The glock to thaw |
| * |
| */ |
| |
| static void thaw_glock(struct gfs2_glock *gl) |
| { |
| if (!test_and_clear_bit(GLF_FROZEN, &gl->gl_flags)) |
| return; |
| if (!lockref_get_not_dead(&gl->gl_lockref)) |
| return; |
| set_bit(GLF_REPLY_PENDING, &gl->gl_flags); |
| gfs2_glock_queue_work(gl, 0); |
| } |
| |
| /** |
| * clear_glock - look at a glock and see if we can free it from glock cache |
| * @gl: the glock to look at |
| * |
| */ |
| |
| static void clear_glock(struct gfs2_glock *gl) |
| { |
| gfs2_glock_remove_from_lru(gl); |
| |
| spin_lock(&gl->gl_lockref.lock); |
| if (!__lockref_is_dead(&gl->gl_lockref)) { |
| gl->gl_lockref.count++; |
| if (gl->gl_state != LM_ST_UNLOCKED) |
| handle_callback(gl, LM_ST_UNLOCKED, 0, false); |
| __gfs2_glock_queue_work(gl, 0); |
| } |
| spin_unlock(&gl->gl_lockref.lock); |
| } |
| |
| /** |
| * gfs2_glock_thaw - Thaw any frozen glocks |
| * @sdp: The super block |
| * |
| */ |
| |
| void gfs2_glock_thaw(struct gfs2_sbd *sdp) |
| { |
| glock_hash_walk(thaw_glock, sdp); |
| } |
| |
| static void dump_glock(struct seq_file *seq, struct gfs2_glock *gl, bool fsid) |
| { |
| spin_lock(&gl->gl_lockref.lock); |
| gfs2_dump_glock(seq, gl, fsid); |
| spin_unlock(&gl->gl_lockref.lock); |
| } |
| |
| static void dump_glock_func(struct gfs2_glock *gl) |
| { |
| dump_glock(NULL, gl, true); |
| } |
| |
| static void withdraw_dq(struct gfs2_glock *gl) |
| { |
| spin_lock(&gl->gl_lockref.lock); |
| if (!__lockref_is_dead(&gl->gl_lockref) && |
| glock_blocked_by_withdraw(gl)) |
| do_error(gl, LM_OUT_ERROR); /* remove pending waiters */ |
| spin_unlock(&gl->gl_lockref.lock); |
| } |
| |
| void gfs2_gl_dq_holders(struct gfs2_sbd *sdp) |
| { |
| glock_hash_walk(withdraw_dq, sdp); |
| } |
| |
| /** |
| * gfs2_gl_hash_clear - Empty out the glock hash table |
| * @sdp: the filesystem |
| * |
| * Called when unmounting the filesystem. |
| */ |
| |
| void gfs2_gl_hash_clear(struct gfs2_sbd *sdp) |
| { |
| set_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags); |
| flush_workqueue(glock_workqueue); |
| glock_hash_walk(clear_glock, sdp); |
| flush_workqueue(glock_workqueue); |
| wait_event_timeout(sdp->sd_kill_wait, |
| atomic_read(&sdp->sd_glock_disposal) == 0, |
| HZ * 600); |
| glock_hash_walk(dump_glock_func, sdp); |
| } |
| |
| static const char *state2str(unsigned state) |
| { |
| switch(state) { |
| case LM_ST_UNLOCKED: |
| return "UN"; |
| case LM_ST_SHARED: |
| return "SH"; |
| case LM_ST_DEFERRED: |
| return "DF"; |
| case LM_ST_EXCLUSIVE: |
| return "EX"; |
| } |
| return "??"; |
| } |
| |
| static const char *hflags2str(char *buf, u16 flags, unsigned long iflags) |
| { |
| char *p = buf; |
| if (flags & LM_FLAG_TRY) |
| *p++ = 't'; |
| if (flags & LM_FLAG_TRY_1CB) |
| *p++ = 'T'; |
| if (flags & LM_FLAG_NOEXP) |
| *p++ = 'e'; |
| if (flags & LM_FLAG_ANY) |
| *p++ = 'A'; |
| if (flags & LM_FLAG_NODE_SCOPE) |
| *p++ = 'n'; |
| if (flags & GL_ASYNC) |
| *p++ = 'a'; |
| if (flags & GL_EXACT) |
| *p++ = 'E'; |
| if (flags & GL_NOCACHE) |
| *p++ = 'c'; |
| if (test_bit(HIF_HOLDER, &iflags)) |
| *p++ = 'H'; |
| if (test_bit(HIF_WAIT, &iflags)) |
| *p++ = 'W'; |
| if (flags & GL_SKIP) |
| *p++ = 's'; |
| *p = 0; |
| return buf; |
| } |
| |
| /** |
| * dump_holder - print information about a glock holder |
| * @seq: the seq_file struct |
| * @gh: the glock holder |
| * @fs_id_buf: pointer to file system id (if requested) |
| * |
| */ |
| |
| static void dump_holder(struct seq_file *seq, const struct gfs2_holder *gh, |
| const char *fs_id_buf) |
| { |
| const char *comm = "(none)"; |
| pid_t owner_pid = 0; |
| char flags_buf[32]; |
| |
| rcu_read_lock(); |
| if (pid_is_meaningful(gh)) { |
| struct task_struct *gh_owner; |
| |
| comm = "(ended)"; |
| owner_pid = pid_nr(gh->gh_owner_pid); |
| gh_owner = pid_task(gh->gh_owner_pid, PIDTYPE_PID); |
| if (gh_owner) |
| comm = gh_owner->comm; |
| } |
| gfs2_print_dbg(seq, "%s H: s:%s f:%s e:%d p:%ld [%s] %pS\n", |
| fs_id_buf, state2str(gh->gh_state), |
| hflags2str(flags_buf, gh->gh_flags, gh->gh_iflags), |
| gh->gh_error, (long)owner_pid, comm, (void *)gh->gh_ip); |
| rcu_read_unlock(); |
| } |
| |
| static const char *gflags2str(char *buf, const struct gfs2_glock *gl) |
| { |
| const unsigned long *gflags = &gl->gl_flags; |
| char *p = buf; |
| |
| if (test_bit(GLF_LOCK, gflags)) |
| *p++ = 'l'; |
| if (test_bit(GLF_DEMOTE, gflags)) |
| *p++ = 'D'; |
| if (test_bit(GLF_PENDING_DEMOTE, gflags)) |
| *p++ = 'd'; |
| if (test_bit(GLF_DEMOTE_IN_PROGRESS, gflags)) |
| *p++ = 'p'; |
| if (test_bit(GLF_DIRTY, gflags)) |
| *p++ = 'y'; |
| if (test_bit(GLF_LFLUSH, gflags)) |
| *p++ = 'f'; |
| if (test_bit(GLF_INVALIDATE_IN_PROGRESS, gflags)) |
| *p++ = 'i'; |
| if (test_bit(GLF_REPLY_PENDING, gflags)) |
| *p++ = 'r'; |
| if (test_bit(GLF_INITIAL, gflags)) |
| *p++ = 'I'; |
| if (test_bit(GLF_FROZEN, gflags)) |
| *p++ = 'F'; |
| if (!list_empty(&gl->gl_holders)) |
| *p++ = 'q'; |
| if (test_bit(GLF_LRU, gflags)) |
| *p++ = 'L'; |
| if (gl->gl_object) |
| *p++ = 'o'; |
| if (test_bit(GLF_BLOCKING, gflags)) |
| *p++ = 'b'; |
| if (test_bit(GLF_FREEING, gflags)) |
| *p++ = 'x'; |
| if (test_bit(GLF_INSTANTIATE_NEEDED, gflags)) |
| *p++ = 'n'; |
| if (test_bit(GLF_INSTANTIATE_IN_PROG, gflags)) |
| *p++ = 'N'; |
| if (test_bit(GLF_TRY_TO_EVICT, gflags)) |
| *p++ = 'e'; |
| if (test_bit(GLF_VERIFY_EVICT, gflags)) |
| *p++ = 'E'; |
| *p = 0; |
| return buf; |
| } |
| |
| /** |
| * gfs2_dump_glock - print information about a glock |
| * @seq: The seq_file struct |
| * @gl: the glock |
| * @fsid: If true, also dump the file system id |
| * |
| * The file format is as follows: |
| * One line per object, capital letters are used to indicate objects |
| * G = glock, I = Inode, R = rgrp, H = holder. Glocks are not indented, |
| * other objects are indented by a single space and follow the glock to |
| * which they are related. Fields are indicated by lower case letters |
| * followed by a colon and the field value, except for strings which are in |
| * [] so that its possible to see if they are composed of spaces for |
| * example. The field's are n = number (id of the object), f = flags, |
| * t = type, s = state, r = refcount, e = error, p = pid. |
| * |
| */ |
| |
| void gfs2_dump_glock(struct seq_file *seq, struct gfs2_glock *gl, bool fsid) |
| { |
| const struct gfs2_glock_operations *glops = gl->gl_ops; |
| unsigned long long dtime; |
| const struct gfs2_holder *gh; |
| char gflags_buf[32]; |
| struct gfs2_sbd *sdp = gl->gl_name.ln_sbd; |
| char fs_id_buf[sizeof(sdp->sd_fsname) + 7]; |
| unsigned long nrpages = 0; |
| |
| if (gl->gl_ops->go_flags & GLOF_ASPACE) { |
| struct address_space *mapping = gfs2_glock2aspace(gl); |
| |
| nrpages = mapping->nrpages; |
| } |
| memset(fs_id_buf, 0, sizeof(fs_id_buf)); |
| if (fsid && sdp) /* safety precaution */ |
| sprintf(fs_id_buf, "fsid=%s: ", sdp->sd_fsname); |
| dtime = jiffies - gl->gl_demote_time; |
| dtime *= 1000000/HZ; /* demote time in uSec */ |
| if (!test_bit(GLF_DEMOTE, &gl->gl_flags)) |
| dtime = 0; |
| gfs2_print_dbg(seq, "%sG: s:%s n:%u/%llx f:%s t:%s d:%s/%llu a:%d " |
| "v:%d r:%d m:%ld p:%lu\n", |
| fs_id_buf, state2str(gl->gl_state), |
| gl->gl_name.ln_type, |
| (unsigned long long)gl->gl_name.ln_number, |
| gflags2str(gflags_buf, gl), |
| state2str(gl->gl_target), |
| state2str(gl->gl_demote_state), dtime, |
| atomic_read(&gl->gl_ail_count), |
| atomic_read(&gl->gl_revokes), |
| (int)gl->gl_lockref.count, gl->gl_hold_time, nrpages); |
| |
| list_for_each_entry(gh, &gl->gl_holders, gh_list) |
| dump_holder(seq, gh, fs_id_buf); |
| |
| if (gl->gl_state != LM_ST_UNLOCKED && glops->go_dump) |
| glops->go_dump(seq, gl, fs_id_buf); |
| } |
| |
| static int gfs2_glstats_seq_show(struct seq_file *seq, void *iter_ptr) |
| { |
| struct gfs2_glock *gl = iter_ptr; |
| |
| seq_printf(seq, "G: n:%u/%llx rtt:%llu/%llu rttb:%llu/%llu irt:%llu/%llu dcnt: %llu qcnt: %llu\n", |
| gl->gl_name.ln_type, |
| (unsigned long long)gl->gl_name.ln_number, |
| (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTT], |
| (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVAR], |
| (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTB], |
| (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SRTTVARB], |
| (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRT], |
| (unsigned long long)gl->gl_stats.stats[GFS2_LKS_SIRTVAR], |
| (unsigned long long)gl->gl_stats.stats[GFS2_LKS_DCOUNT], |
| (unsigned long long)gl->gl_stats.stats[GFS2_LKS_QCOUNT]); |
| return 0; |
| } |
| |
| static const char *gfs2_gltype[] = { |
| "type", |
| "reserved", |
| "nondisk", |
| "inode", |
| "rgrp", |
| "meta", |
| "iopen", |
| "flock", |
| "plock", |
| "quota", |
| "journal", |
| }; |
| |
| static const char *gfs2_stype[] = { |
| [GFS2_LKS_SRTT] = "srtt", |
| [GFS2_LKS_SRTTVAR] = "srttvar", |
| [GFS2_LKS_SRTTB] = "srttb", |
| [GFS2_LKS_SRTTVARB] = "srttvarb", |
| [GFS2_LKS_SIRT] = "sirt", |
| [GFS2_LKS_SIRTVAR] = "sirtvar", |
| [GFS2_LKS_DCOUNT] = "dlm", |
| [GFS2_LKS_QCOUNT] = "queue", |
| }; |
| |
| #define GFS2_NR_SBSTATS (ARRAY_SIZE(gfs2_gltype) * ARRAY_SIZE(gfs2_stype)) |
| |
| static int gfs2_sbstats_seq_show(struct seq_file *seq, void *iter_ptr) |
| { |
| struct gfs2_sbd *sdp = seq->private; |
| loff_t pos = *(loff_t *)iter_ptr; |
| unsigned index = pos >> 3; |
| unsigned subindex = pos & 0x07; |
| int i; |
| |
| if (index == 0 && subindex != 0) |
| return 0; |
| |
| seq_printf(seq, "%-10s %8s:", gfs2_gltype[index], |
| (index == 0) ? "cpu": gfs2_stype[subindex]); |
| |
| for_each_possible_cpu(i) { |
| const struct gfs2_pcpu_lkstats *lkstats = per_cpu_ptr(sdp->sd_lkstats, i); |
| |
| if (index == 0) |
| seq_printf(seq, " %15u", i); |
| else |
| seq_printf(seq, " %15llu", (unsigned long long)lkstats-> |
| lkstats[index - 1].stats[subindex]); |
| } |
| seq_putc(seq, '\n'); |
| return 0; |
| } |
| |
| int __init gfs2_glock_init(void) |
| { |
| int i, ret; |
| |
| ret = rhashtable_init(&gl_hash_table, &ht_parms); |
| if (ret < 0) |
| return ret; |
| |
| glock_workqueue = alloc_workqueue("glock_workqueue", WQ_MEM_RECLAIM | |
| WQ_HIGHPRI | WQ_FREEZABLE, 0); |
| if (!glock_workqueue) { |
| rhashtable_destroy(&gl_hash_table); |
| return -ENOMEM; |
| } |
| |
| ret = register_shrinker(&glock_shrinker, "gfs2-glock"); |
| if (ret) { |
| destroy_workqueue(glock_workqueue); |
| rhashtable_destroy(&gl_hash_table); |
| return ret; |
| } |
| |
| for (i = 0; i < GLOCK_WAIT_TABLE_SIZE; i++) |
| init_waitqueue_head(glock_wait_table + i); |
| |
| return 0; |
| } |
| |
| void gfs2_glock_exit(void) |
| { |
| unregister_shrinker(&glock_shrinker); |
| rhashtable_destroy(&gl_hash_table); |
| destroy_workqueue(glock_workqueue); |
| } |
| |
| static void gfs2_glock_iter_next(struct gfs2_glock_iter *gi, loff_t n) |
| { |
| struct gfs2_glock *gl = gi->gl; |
| |
| if (gl) { |
| if (n == 0) |
| return; |
| if (!lockref_put_not_zero(&gl->gl_lockref)) |
| gfs2_glock_queue_put(gl); |
| } |
| for (;;) { |
| gl = rhashtable_walk_next(&gi->hti); |
| if (IS_ERR_OR_NULL(gl)) { |
| if (gl == ERR_PTR(-EAGAIN)) { |
| n = 1; |
| continue; |
| } |
| gl = NULL; |
| break; |
| } |
| if (gl->gl_name.ln_sbd != gi->sdp) |
| continue; |
| if (n <= 1) { |
| if (!lockref_get_not_dead(&gl->gl_lockref)) |
| continue; |
| break; |
| } else { |
| if (__lockref_is_dead(&gl->gl_lockref)) |
| continue; |
| n--; |
| } |
| } |
| gi->gl = gl; |
| } |
| |
| static void *gfs2_glock_seq_start(struct seq_file *seq, loff_t *pos) |
| __acquires(RCU) |
| { |
| struct gfs2_glock_iter *gi = seq->private; |
| loff_t n; |
| |
| /* |
| * We can either stay where we are, skip to the next hash table |
| * entry, or start from the beginning. |
| */ |
| if (*pos < gi->last_pos) { |
| rhashtable_walk_exit(&gi->hti); |
| rhashtable_walk_enter(&gl_hash_table, &gi->hti); |
| n = *pos + 1; |
| } else { |
| n = *pos - gi->last_pos; |
| } |
| |
| rhashtable_walk_start(&gi->hti); |
| |
| gfs2_glock_iter_next(gi, n); |
| gi->last_pos = *pos; |
| return gi->gl; |
| } |
| |
| static void *gfs2_glock_seq_next(struct seq_file *seq, void *iter_ptr, |
| loff_t *pos) |
| { |
| struct gfs2_glock_iter *gi = seq->private; |
| |
| (*pos)++; |
| gi->last_pos = *pos; |
| gfs2_glock_iter_next(gi, 1); |
| return gi->gl; |
| } |
| |
| static void gfs2_glock_seq_stop(struct seq_file *seq, void *iter_ptr) |
| __releases(RCU) |
| { |
| struct gfs2_glock_iter *gi = seq->private; |
| |
| rhashtable_walk_stop(&gi->hti); |
| } |
| |
| static int gfs2_glock_seq_show(struct seq_file *seq, void *iter_ptr) |
| { |
| dump_glock(seq, iter_ptr, false); |
| return 0; |
| } |
| |
| static void *gfs2_sbstats_seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| preempt_disable(); |
| if (*pos >= GFS2_NR_SBSTATS) |
| return NULL; |
| return pos; |
| } |
| |
| static void *gfs2_sbstats_seq_next(struct seq_file *seq, void *iter_ptr, |
| loff_t *pos) |
| { |
| (*pos)++; |
| if (*pos >= GFS2_NR_SBSTATS) |
| return NULL; |
| return pos; |
| } |
| |
| static void gfs2_sbstats_seq_stop(struct seq_file *seq, void *iter_ptr) |
| { |
| preempt_enable(); |
| } |
| |
| static const struct seq_operations gfs2_glock_seq_ops = { |
| .start = gfs2_glock_seq_start, |
| .next = gfs2_glock_seq_next, |
| .stop = gfs2_glock_seq_stop, |
| .show = gfs2_glock_seq_show, |
| }; |
| |
| static const struct seq_operations gfs2_glstats_seq_ops = { |
| .start = gfs2_glock_seq_start, |
| .next = gfs2_glock_seq_next, |
| .stop = gfs2_glock_seq_stop, |
| .show = gfs2_glstats_seq_show, |
| }; |
| |
| static const struct seq_operations gfs2_sbstats_sops = { |
| .start = gfs2_sbstats_seq_start, |
| .next = gfs2_sbstats_seq_next, |
| .stop = gfs2_sbstats_seq_stop, |
| .show = gfs2_sbstats_seq_show, |
| }; |
| |
| #define GFS2_SEQ_GOODSIZE min(PAGE_SIZE << PAGE_ALLOC_COSTLY_ORDER, 65536UL) |
| |
| static int __gfs2_glocks_open(struct inode *inode, struct file *file, |
| const struct seq_operations *ops) |
| { |
| int ret = seq_open_private(file, ops, sizeof(struct gfs2_glock_iter)); |
| if (ret == 0) { |
| struct seq_file *seq = file->private_data; |
| struct gfs2_glock_iter *gi = seq->private; |
| |
| gi->sdp = inode->i_private; |
| seq->buf = kmalloc(GFS2_SEQ_GOODSIZE, GFP_KERNEL | __GFP_NOWARN); |
| if (seq->buf) |
| seq->size = GFS2_SEQ_GOODSIZE; |
| /* |
| * Initially, we are "before" the first hash table entry; the |
| * first call to rhashtable_walk_next gets us the first entry. |
| */ |
| gi->last_pos = -1; |
| gi->gl = NULL; |
| rhashtable_walk_enter(&gl_hash_table, &gi->hti); |
| } |
| return ret; |
| } |
| |
| static int gfs2_glocks_open(struct inode *inode, struct file *file) |
| { |
| return __gfs2_glocks_open(inode, file, &gfs2_glock_seq_ops); |
| } |
| |
| static int gfs2_glocks_release(struct inode *inode, struct file *file) |
| { |
| struct seq_file *seq = file->private_data; |
| struct gfs2_glock_iter *gi = seq->private; |
| |
| if (gi->gl) |
| gfs2_glock_put(gi->gl); |
| rhashtable_walk_exit(&gi->hti); |
| return seq_release_private(inode, file); |
| } |
| |
| static int gfs2_glstats_open(struct inode *inode, struct file *file) |
| { |
| return __gfs2_glocks_open(inode, file, &gfs2_glstats_seq_ops); |
| } |
| |
| static const struct file_operations gfs2_glocks_fops = { |
| .owner = THIS_MODULE, |
| .open = gfs2_glocks_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = gfs2_glocks_release, |
| }; |
| |
| static const struct file_operations gfs2_glstats_fops = { |
| .owner = THIS_MODULE, |
| .open = gfs2_glstats_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = gfs2_glocks_release, |
| }; |
| |
| struct gfs2_glockfd_iter { |
| struct super_block *sb; |
| unsigned int tgid; |
| struct task_struct *task; |
| unsigned int fd; |
| struct file *file; |
| }; |
| |
| static struct task_struct *gfs2_glockfd_next_task(struct gfs2_glockfd_iter *i) |
| { |
| struct pid_namespace *ns = task_active_pid_ns(current); |
| struct pid *pid; |
| |
| if (i->task) |
| put_task_struct(i->task); |
| |
| rcu_read_lock(); |
| retry: |
| i->task = NULL; |
| pid = find_ge_pid(i->tgid, ns); |
| if (pid) { |
| i->tgid = pid_nr_ns(pid, ns); |
| i->task = pid_task(pid, PIDTYPE_TGID); |
| if (!i->task) { |
| i->tgid++; |
| goto retry; |
| } |
| get_task_struct(i->task); |
| } |
| rcu_read_unlock(); |
| return i->task; |
| } |
| |
| static struct file *gfs2_glockfd_next_file(struct gfs2_glockfd_iter *i) |
| { |
| if (i->file) { |
| fput(i->file); |
| i->file = NULL; |
| } |
| |
| rcu_read_lock(); |
| for(;; i->fd++) { |
| struct inode *inode; |
| |
| i->file = task_lookup_next_fd_rcu(i->task, &i->fd); |
| if (!i->file) { |
| i->fd = 0; |
| break; |
| } |
| inode = file_inode(i->file); |
| if (inode->i_sb != i->sb) |
| continue; |
| if (get_file_rcu(i->file)) |
| break; |
| } |
| rcu_read_unlock(); |
| return i->file; |
| } |
| |
| static void *gfs2_glockfd_seq_start(struct seq_file *seq, loff_t *pos) |
| { |
| struct gfs2_glockfd_iter *i = seq->private; |
| |
| if (*pos) |
| return NULL; |
| while (gfs2_glockfd_next_task(i)) { |
| if (gfs2_glockfd_next_file(i)) |
| return i; |
| i->tgid++; |
| } |
| return NULL; |
| } |
| |
| static void *gfs2_glockfd_seq_next(struct seq_file *seq, void *iter_ptr, |
| loff_t *pos) |
| { |
| struct gfs2_glockfd_iter *i = seq->private; |
| |
| (*pos)++; |
| i->fd++; |
| do { |
| if (gfs2_glockfd_next_file(i)) |
| return i; |
| i->tgid++; |
| } while (gfs2_glockfd_next_task(i)); |
| return NULL; |
| } |
| |
| static void gfs2_glockfd_seq_stop(struct seq_file *seq, void *iter_ptr) |
| { |
| struct gfs2_glockfd_iter *i = seq->private; |
| |
| if (i->file) |
| fput(i->file); |
| if (i->task) |
| put_task_struct(i->task); |
| } |
| |
| static void gfs2_glockfd_seq_show_flock(struct seq_file *seq, |
| struct gfs2_glockfd_iter *i) |
| { |
| struct gfs2_file *fp = i->file->private_data; |
| struct gfs2_holder *fl_gh = &fp->f_fl_gh; |
| struct lm_lockname gl_name = { .ln_type = LM_TYPE_RESERVED }; |
| |
| if (!READ_ONCE(fl_gh->gh_gl)) |
| return; |
| |
| spin_lock(&i->file->f_lock); |
| if (gfs2_holder_initialized(fl_gh)) |
| gl_name = fl_gh->gh_gl->gl_name; |
| spin_unlock(&i->file->f_lock); |
| |
| if (gl_name.ln_type != LM_TYPE_RESERVED) { |
| seq_printf(seq, "%d %u %u/%llx\n", |
| i->tgid, i->fd, gl_name.ln_type, |
| (unsigned long long)gl_name.ln_number); |
| } |
| } |
| |
| static int gfs2_glockfd_seq_show(struct seq_file *seq, void *iter_ptr) |
| { |
| struct gfs2_glockfd_iter *i = seq->private; |
| struct inode *inode = file_inode(i->file); |
| struct gfs2_glock *gl; |
| |
| inode_lock_shared(inode); |
| gl = GFS2_I(inode)->i_iopen_gh.gh_gl; |
| if (gl) { |
| seq_printf(seq, "%d %u %u/%llx\n", |
| i->tgid, i->fd, gl->gl_name.ln_type, |
| (unsigned long long)gl->gl_name.ln_number); |
| } |
| gfs2_glockfd_seq_show_flock(seq, i); |
| inode_unlock_shared(inode); |
| return 0; |
| } |
| |
| static const struct seq_operations gfs2_glockfd_seq_ops = { |
| .start = gfs2_glockfd_seq_start, |
| .next = gfs2_glockfd_seq_next, |
| .stop = gfs2_glockfd_seq_stop, |
| .show = gfs2_glockfd_seq_show, |
| }; |
| |
| static int gfs2_glockfd_open(struct inode *inode, struct file *file) |
| { |
| struct gfs2_glockfd_iter *i; |
| struct gfs2_sbd *sdp = inode->i_private; |
| |
| i = __seq_open_private(file, &gfs2_glockfd_seq_ops, |
| sizeof(struct gfs2_glockfd_iter)); |
| if (!i) |
| return -ENOMEM; |
| i->sb = sdp->sd_vfs; |
| return 0; |
| } |
| |
| static const struct file_operations gfs2_glockfd_fops = { |
| .owner = THIS_MODULE, |
| .open = gfs2_glockfd_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_private, |
| }; |
| |
| DEFINE_SEQ_ATTRIBUTE(gfs2_sbstats); |
| |
| void gfs2_create_debugfs_file(struct gfs2_sbd *sdp) |
| { |
| sdp->debugfs_dir = debugfs_create_dir(sdp->sd_table_name, gfs2_root); |
| |
| debugfs_create_file("glocks", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp, |
| &gfs2_glocks_fops); |
| |
| debugfs_create_file("glockfd", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp, |
| &gfs2_glockfd_fops); |
| |
| debugfs_create_file("glstats", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp, |
| &gfs2_glstats_fops); |
| |
| debugfs_create_file("sbstats", S_IFREG | S_IRUGO, sdp->debugfs_dir, sdp, |
| &gfs2_sbstats_fops); |
| } |
| |
| void gfs2_delete_debugfs_file(struct gfs2_sbd *sdp) |
| { |
| debugfs_remove_recursive(sdp->debugfs_dir); |
| sdp->debugfs_dir = NULL; |
| } |
| |
| void gfs2_register_debugfs(void) |
| { |
| gfs2_root = debugfs_create_dir("gfs2", NULL); |
| } |
| |
| void gfs2_unregister_debugfs(void) |
| { |
| debugfs_remove(gfs2_root); |
| gfs2_root = NULL; |
| } |