Since commit c69899a17ca4 "NFSv4: Update of VFS byte range lock must be
atomic with the stateid update", NFSv4 has been inserting locks in rpciod
worker context. The result is that the file_lock's fl_nspid is the
kworker's pid instead of the original userspace pid.
The fl_nspid is only used to represent the namespaced virtual pid number
when displaying locks or returning from F_GETLK. There's no reason to set
it for every inserted lock, since we can usually just look it up from
fl_pid. So, instead of looking up and holding struct pid for every lock,
let's just look up the virtual pid number from fl_pid when it is needed.
That means we can remove fl_nspid entirely.
Signed-off-by: Benjamin Coddington <bcodd...@redhat.com>
---
fs/locks.c | 52 +++++++++++++++++++++++++++++-----------------------
include/linux/fs.h | 1 -
2 files changed, 29 insertions(+), 24 deletions(-)
diff --git a/fs/locks.c b/fs/locks.c
index d7daa6c8932f..8d48e4c42ed3 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -733,7 +733,6 @@ static void locks_wake_up_blocks(struct file_lock *blocker)
static void
locks_insert_lock_ctx(struct file_lock *fl, struct list_head *before)
{
- fl->fl_nspid = get_pid(task_tgid(current));
list_add_tail(&fl->fl_list, before);
locks_insert_global_locks(fl);
}
@@ -743,10 +742,6 @@ locks_unlink_lock_ctx(struct file_lock *fl)
{
locks_delete_global_locks(fl);
list_del_init(&fl->fl_list);
- if (fl->fl_nspid) {
- put_pid(fl->fl_nspid);
- fl->fl_nspid = NULL;
- }
locks_wake_up_blocks(fl);
}
@@ -823,8 +818,6 @@ posix_test_lock(struct file *filp, struct file_lock *fl)
list_for_each_entry(cfl, &ctx->flc_posix, fl_list) {
if (posix_locks_conflict(fl, cfl)) {
locks_copy_conflock(fl, cfl);
- if (cfl->fl_nspid)
- fl->fl_pid = pid_vnr(cfl->fl_nspid);
goto out;
}
}
@@ -2048,6 +2041,25 @@ int vfs_test_lock(struct file *filp, struct file_lock
*fl)
}
EXPORT_SYMBOL_GPL(vfs_test_lock);
+/**
+ * locks_translate_pid - translate a pid number into a namespace
+ * @nr: The pid number in the init_pid_ns
+ * @ns: The namespace into which the pid should be translated
+ *
+ * Used to tranlate a fl_pid into a namespace virtual pid number
+ */
+static pid_t locks_translate_pid(int init_nr, struct pid_namespace *ns)
+{
+ pid_t vnr;
+ struct pid *pid;
+
+ rcu_read_lock();
+ pid = find_pid_ns(init_nr, &init_pid_ns);
+ vnr = pid_nr_ns(pid, ns);
+ rcu_read_unlock();
+ return vnr;
+}
+
static int posix_lock_to_flock(struct flock *flock, struct file_lock *fl)
{
flock->l_pid = IS_OFDLCK(fl) ? -1 : fl->fl_pid;
@@ -2584,22 +2596,16 @@ static void lock_get_status(struct seq_file *f, struct
file_lock *fl,
{
struct inode *inode = NULL;
unsigned int fl_pid;
+ struct pid_namespace *proc_pidns = file_inode(f->file)->i_sb->s_fs_info;
- 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;
+ fl_pid = locks_translate_pid(fl->fl_pid, 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;
if (fl->fl_file != NULL)
inode = locks_inode(fl->fl_file);
@@ -2674,7 +2680,7 @@ static int locks_show(struct seq_file *f, void *v)
fl = hlist_entry(v, struct file_lock, fl_link);
- if (fl->fl_nspid && !pid_nr_ns(fl->fl_nspid, proc_pidns))
+ if (locks_translate_pid(fl->fl_pid, proc_pidns) == 0)
return 0;
lock_get_status(f, fl, iter->li_pos, "");
diff --git a/include/linux/fs.h b/include/linux/fs.h
index aa4affb38c39..b013fac515f7 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -984,7 +984,6 @@ struct file_lock {
unsigned char fl_type;
unsigned int fl_pid;
int fl_link_cpu; /* what cpu's list is this on? */
- struct pid *fl_nspid;
wait_queue_head_t fl_wait;
struct file *fl_file;
loff_t fl_start;
--
2.9.3
