Commit 0f0a0e54 authored by Matthew Wilcox's avatar Matthew Wilcox
Browse files

devpts: Convert to new IDA API 



ida_alloc_max() matches what this driver wants to do.  Also removes a
call to ida_pre_get().  We no longer need the protection of the mutex,
so convert pty_count to an atomic_t and remove the mutex entirely.

Signed-off-by: default avatarMatthew Wilcox <willy@infradead.org>
parent 169b480e

fs/devpts/inode.c

+13 −34
Original line number Diff line number Diff line
@@ -46,7 +46,7 @@ static int pty_limit = NR_UNIX98_PTY_DEFAULT; 
static int pty_reserve = NR_UNIX98_PTY_RESERVE;

static int pty_limit_min;

static int pty_limit_max = INT_MAX;

static int pty_count;

static atomic_t pty_count = ATOMIC_INIT(0);



static struct ctl_table pty_table[] = {

	{
@@ -93,8 +93,6 @@ static struct ctl_table pty_root_table[] = { 
	{}

};



static DEFINE_MUTEX(allocated_ptys_lock);



struct pts_mount_opts {

	int setuid;

	int setgid;
@@ -533,44 +531,25 @@ static struct file_system_type devpts_fs_type = { 


int devpts_new_index(struct pts_fs_info *fsi)

{

	int index;

	int ida_ret;

	int index = -ENOSPC;



retry:

	if (!ida_pre_get(&fsi->allocated_ptys, GFP_KERNEL))

		return -ENOMEM;

	if (atomic_inc_return(&pty_count) >= (pty_limit -

			  (fsi->mount_opts.reserve ? 0 : pty_reserve)))

		goto out;



	mutex_lock(&allocated_ptys_lock);

	if (pty_count >= (pty_limit -

			  (fsi->mount_opts.reserve ? 0 : pty_reserve))) {

		mutex_unlock(&allocated_ptys_lock);

		return -ENOSPC;

	}

	index = ida_alloc_max(&fsi->allocated_ptys, fsi->mount_opts.max - 1,

			GFP_KERNEL);



	ida_ret = ida_get_new(&fsi->allocated_ptys, &index);

	if (ida_ret < 0) {

		mutex_unlock(&allocated_ptys_lock);

		if (ida_ret == -EAGAIN)

			goto retry;

		return -EIO;

	}



	if (index >= fsi->mount_opts.max) {

		ida_remove(&fsi->allocated_ptys, index);

		mutex_unlock(&allocated_ptys_lock);

		return -ENOSPC;

	}

	pty_count++;

	mutex_unlock(&allocated_ptys_lock);

out:

	if (index < 0)

		atomic_dec(&pty_count);

	return index;

}



void devpts_kill_index(struct pts_fs_info *fsi, int idx)

{

	mutex_lock(&allocated_ptys_lock);

	ida_remove(&fsi->allocated_ptys, idx);

	pty_count--;

	mutex_unlock(&allocated_ptys_lock);

	ida_free(&fsi->allocated_ptys, idx);

	atomic_dec(&pty_count);

}



/**

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