#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>
/*
* 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.
/* 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
*/
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
return -ENOMEM;
}
+ percpu_down_read_preempt_disable(&file_rwsem);
spin_lock(&ctx->flc_lock);
if (request->fl_flags & FL_ACCESS)
goto 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);
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
}
out:
spin_unlock(&ctx->flc_lock);
+ percpu_up_read_preempt_enable(&file_rwsem);
/*
* Free any unused locks.
*/
return error;
}
+ percpu_down_read_preempt_disable(&file_rwsem);
spin_lock(&ctx->flc_lock);
time_out_leases(inode, &dispose);
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);
}
out:
spin_unlock(&ctx->flc_lock);
+ percpu_up_read_preempt_enable(&file_rwsem);
locks_dispose_list(&dispose);
locks_free_lock(new_fl);
return error;
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);
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);
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 &&
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;
}
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)
{
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)
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)
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 = {
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;
}
projects / cascardo / linux.git / blobdiff