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path: root/fs/devpts/inode.c
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Diffstat (limited to 'fs/devpts/inode.c')
-rw-r--r--fs/devpts/inode.c47
1 files changed, 13 insertions, 34 deletions
diff --git a/fs/devpts/inode.c b/fs/devpts/inode.c
index e072e955ce33..c53814539070 100644
--- a/fs/devpts/inode.c
+++ b/fs/devpts/inode.c
@@ -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;
-
-retry:
- if (!ida_pre_get(&fsi->allocated_ptys, GFP_KERNEL))
- return -ENOMEM;
-
- mutex_lock(&allocated_ptys_lock);
- if (pty_count >= (pty_limit -
- (fsi->mount_opts.reserve ? 0 : pty_reserve))) {
- mutex_unlock(&allocated_ptys_lock);
- return -ENOSPC;
- }
+ int index = -ENOSPC;
- 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 (atomic_inc_return(&pty_count) >= (pty_limit -
+ (fsi->mount_opts.reserve ? 0 : pty_reserve)))
+ goto out;
- 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);
+ index = ida_alloc_max(&fsi->allocated_ptys, fsi->mount_opts.max - 1,
+ GFP_KERNEL);
+
+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);
}
/**