diff options
Diffstat (limited to 'fs/locks.c')
| -rw-r--r-- | fs/locks.c | 89 |
1 files changed, 68 insertions, 21 deletions
diff --git a/fs/locks.c b/fs/locks.c index ee1b15f6fc13..90ec67108b22 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -127,7 +127,6 @@ #include <linux/pid_namespace.h> #include <linux/hashtable.h> #include <linux/percpu.h> -#include <linux/lglock.h> #define CREATE_TRACE_POINTS #include <trace/events/filelock.h> @@ -158,12 +157,18 @@ int lease_break_time = 45; /* * The global file_lock_list is only used for displaying /proc/locks, so we - * keep a list on each CPU, with each list protected by its own spinlock via - * the file_lock_lglock. Note that alterations to the list also require that - * the relevant flc_lock is held. + * keep a list on each CPU, with each list protected by its own spinlock. + * Global serialization is done using file_rwsem. + * + * Note that alterations to the list also require that the relevant flc_lock is + * held. */ -DEFINE_STATIC_LGLOCK(file_lock_lglock); -static DEFINE_PER_CPU(struct hlist_head, file_lock_list); +struct file_lock_list_struct { + spinlock_t lock; + struct hlist_head hlist; +}; +static DEFINE_PER_CPU(struct file_lock_list_struct, file_lock_list); +DEFINE_STATIC_PERCPU_RWSEM(file_rwsem); /* * The blocked_hash is used to find POSIX lock loops for deadlock detection. @@ -587,15 +592,23 @@ static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2) /* Must be called with the flc_lock held! */ static void locks_insert_global_locks(struct file_lock *fl) { - lg_local_lock(&file_lock_lglock); + struct file_lock_list_struct *fll = this_cpu_ptr(&file_lock_list); + + percpu_rwsem_assert_held(&file_rwsem); + + spin_lock(&fll->lock); fl->fl_link_cpu = smp_processor_id(); - hlist_add_head(&fl->fl_link, this_cpu_ptr(&file_lock_list)); - lg_local_unlock(&file_lock_lglock); + hlist_add_head(&fl->fl_link, &fll->hlist); + spin_unlock(&fll->lock); } /* Must be called with the flc_lock held! */ static void locks_delete_global_locks(struct file_lock *fl) { + struct file_lock_list_struct *fll; + + percpu_rwsem_assert_held(&file_rwsem); + /* * Avoid taking lock if already unhashed. This is safe since this check * is done while holding the flc_lock, and new insertions into the list @@ -603,9 +616,11 @@ static void locks_delete_global_locks(struct file_lock *fl) */ if (hlist_unhashed(&fl->fl_link)) return; - lg_local_lock_cpu(&file_lock_lglock, fl->fl_link_cpu); + + fll = per_cpu_ptr(&file_lock_list, fl->fl_link_cpu); + spin_lock(&fll->lock); hlist_del_init(&fl->fl_link); - lg_local_unlock_cpu(&file_lock_lglock, fl->fl_link_cpu); + spin_unlock(&fll->lock); } static unsigned long @@ -915,6 +930,7 @@ static int flock_lock_inode(struct inode *inode, struct file_lock *request) return -ENOMEM; } + percpu_down_read_preempt_disable(&file_rwsem); spin_lock(&ctx->flc_lock); if (request->fl_flags & FL_ACCESS) goto find_conflict; @@ -955,6 +971,7 @@ find_conflict: out: spin_unlock(&ctx->flc_lock); + percpu_up_read_preempt_enable(&file_rwsem); if (new_fl) locks_free_lock(new_fl); locks_dispose_list(&dispose); @@ -991,6 +1008,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request, new_fl2 = locks_alloc_lock(); } + percpu_down_read_preempt_disable(&file_rwsem); spin_lock(&ctx->flc_lock); /* * New lock request. Walk all POSIX locks and look for conflicts. If @@ -1162,6 +1180,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request, } out: spin_unlock(&ctx->flc_lock); + percpu_up_read_preempt_enable(&file_rwsem); /* * Free any unused locks. */ @@ -1436,6 +1455,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) return error; } + percpu_down_read_preempt_disable(&file_rwsem); spin_lock(&ctx->flc_lock); time_out_leases(inode, &dispose); @@ -1487,9 +1507,13 @@ restart: locks_insert_block(fl, new_fl); trace_break_lease_block(inode, new_fl); spin_unlock(&ctx->flc_lock); + percpu_up_read_preempt_enable(&file_rwsem); + locks_dispose_list(&dispose); error = wait_event_interruptible_timeout(new_fl->fl_wait, !new_fl->fl_next, break_time); + + percpu_down_read_preempt_disable(&file_rwsem); spin_lock(&ctx->flc_lock); trace_break_lease_unblock(inode, new_fl); locks_delete_block(new_fl); @@ -1506,6 +1530,7 @@ restart: } out: spin_unlock(&ctx->flc_lock); + percpu_up_read_preempt_enable(&file_rwsem); locks_dispose_list(&dispose); locks_free_lock(new_fl); return error; @@ -1660,6 +1685,7 @@ generic_add_lease(struct file *filp, long arg, struct file_lock **flp, void **pr return -EINVAL; } + percpu_down_read_preempt_disable(&file_rwsem); spin_lock(&ctx->flc_lock); time_out_leases(inode, &dispose); error = check_conflicting_open(dentry, arg, lease->fl_flags); @@ -1730,6 +1756,7 @@ out_setup: lease->fl_lmops->lm_setup(lease, priv); out: spin_unlock(&ctx->flc_lock); + percpu_up_read_preempt_enable(&file_rwsem); locks_dispose_list(&dispose); if (is_deleg) inode_unlock(inode); @@ -1752,6 +1779,7 @@ static int generic_delete_lease(struct file *filp, void *owner) return error; } + percpu_down_read_preempt_disable(&file_rwsem); spin_lock(&ctx->flc_lock); list_for_each_entry(fl, &ctx->flc_lease, fl_list) { if (fl->fl_file == filp && @@ -1764,6 +1792,7 @@ static int generic_delete_lease(struct file *filp, void *owner) if (victim) error = fl->fl_lmops->lm_change(victim, F_UNLCK, &dispose); spin_unlock(&ctx->flc_lock); + percpu_up_read_preempt_enable(&file_rwsem); locks_dispose_list(&dispose); return error; } @@ -2574,9 +2603,20 @@ static void lock_get_status(struct seq_file *f, struct file_lock *fl, struct inode *inode = NULL; unsigned int fl_pid; - if (fl->fl_nspid) - fl_pid = pid_vnr(fl->fl_nspid); - else + if (fl->fl_nspid) { + struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; + + /* Don't let fl_pid change based on who is reading the file */ + fl_pid = pid_nr_ns(fl->fl_nspid, proc_pidns); + + /* + * If there isn't a fl_pid don't display who is waiting on + * the lock if we are called from locks_show, or if we are + * called from __show_fd_info - skip lock entirely + */ + if (fl_pid == 0) + return; + } else fl_pid = fl->fl_pid; if (fl->fl_file != NULL) @@ -2648,9 +2688,13 @@ static int locks_show(struct seq_file *f, void *v) { struct locks_iterator *iter = f->private; struct file_lock *fl, *bfl; + struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info; fl = hlist_entry(v, struct file_lock, fl_link); + if (fl->fl_nspid && !pid_nr_ns(fl->fl_nspid, proc_pidns)) + return 0; + lock_get_status(f, fl, iter->li_pos, ""); list_for_each_entry(bfl, &fl->fl_block, fl_block) @@ -2703,9 +2747,9 @@ static void *locks_start(struct seq_file *f, loff_t *pos) struct locks_iterator *iter = f->private; iter->li_pos = *pos + 1; - lg_global_lock(&file_lock_lglock); + percpu_down_write(&file_rwsem); spin_lock(&blocked_lock_lock); - return seq_hlist_start_percpu(&file_lock_list, &iter->li_cpu, *pos); + return seq_hlist_start_percpu(&file_lock_list.hlist, &iter->li_cpu, *pos); } static void *locks_next(struct seq_file *f, void *v, loff_t *pos) @@ -2713,14 +2757,14 @@ static void *locks_next(struct seq_file *f, void *v, loff_t *pos) struct locks_iterator *iter = f->private; ++iter->li_pos; - return seq_hlist_next_percpu(v, &file_lock_list, &iter->li_cpu, pos); + return seq_hlist_next_percpu(v, &file_lock_list.hlist, &iter->li_cpu, pos); } static void locks_stop(struct seq_file *f, void *v) __releases(&blocked_lock_lock) { spin_unlock(&blocked_lock_lock); - lg_global_unlock(&file_lock_lglock); + percpu_up_write(&file_rwsem); } static const struct seq_operations locks_seq_operations = { @@ -2761,10 +2805,13 @@ static int __init filelock_init(void) filelock_cache = kmem_cache_create("file_lock_cache", sizeof(struct file_lock), 0, SLAB_PANIC, NULL); - lg_lock_init(&file_lock_lglock, "file_lock_lglock"); - for_each_possible_cpu(i) - INIT_HLIST_HEAD(per_cpu_ptr(&file_lock_list, i)); + for_each_possible_cpu(i) { + struct file_lock_list_struct *fll = per_cpu_ptr(&file_lock_list, i); + + spin_lock_init(&fll->lock); + INIT_HLIST_HEAD(&fll->hlist); + } return 0; } |