diff options
| -rw-r--r-- | fs/proc/base.c | 52 |
1 files changed, 24 insertions, 28 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index be8e17cabfc7..9b423fec9732 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1658,13 +1658,18 @@ int pid_revalidate(struct dentry *dentry, unsigned int flags) return 0; } +static inline bool proc_inode_is_dead(struct inode *inode) +{ + return !proc_pid(inode)->tasks[PIDTYPE_PID].first; +} + int pid_delete_dentry(const struct dentry *dentry) { /* Is the task we represent dead? * If so, then don't put the dentry on the lru list, * kill it immediately. */ - return !proc_pid(dentry->d_inode)->tasks[PIDTYPE_PID].first; + return proc_inode_is_dead(dentry->d_inode); } const struct dentry_operations pid_dentry_operations = @@ -3092,34 +3097,35 @@ out_no_task: * In the case of a seek we start with the leader and walk nr * threads past it. */ -static struct task_struct *first_tid(struct task_struct *leader, - int tid, int nr, struct pid_namespace *ns) +static struct task_struct *first_tid(struct pid *pid, int tid, + int nr, struct pid_namespace *ns) { - struct task_struct *pos; + struct task_struct *pos, *task; rcu_read_lock(); - /* Attempt to start with the pid of a thread */ + task = pid_task(pid, PIDTYPE_PID); + if (!task) + goto fail; + + /* Attempt to start with the tid of a thread */ if (tid && (nr > 0)) { pos = find_task_by_pid_ns(tid, ns); - if (pos && (pos->group_leader == leader)) + if (pos && same_thread_group(pos, task)) goto found; } /* If nr exceeds the number of threads there is nothing todo */ - if (nr && nr >= get_nr_threads(leader)) - goto fail; - /* It could be unhashed before we take rcu lock */ - if (!pid_alive(leader)) + if (nr && nr >= get_nr_threads(task)) goto fail; /* If we haven't found our starting place yet start * with the leader and walk nr threads forward. */ - pos = leader; + pos = task = task->group_leader; do { if (nr-- <= 0) goto found; - } while_each_thread(leader, pos); + } while_each_thread(task, pos); fail: pos = NULL; goto out; @@ -3155,25 +3161,16 @@ static struct task_struct *next_tid(struct task_struct *start) /* for the /proc/TGID/task/ directories */ static int proc_task_readdir(struct file *file, struct dir_context *ctx) { - struct task_struct *leader = NULL; - struct task_struct *task = get_proc_task(file_inode(file)); + struct inode *inode = file_inode(file); + struct task_struct *task; struct pid_namespace *ns; int tid; - if (!task) - return -ENOENT; - rcu_read_lock(); - if (pid_alive(task)) { - leader = task->group_leader; - get_task_struct(leader); - } - rcu_read_unlock(); - put_task_struct(task); - if (!leader) + if (proc_inode_is_dead(inode)) return -ENOENT; if (!dir_emit_dots(file, ctx)) - goto out; + return 0; /* f_version caches the tgid value that the last readdir call couldn't * return. lseek aka telldir automagically resets f_version to 0. @@ -3181,7 +3178,7 @@ static int proc_task_readdir(struct file *file, struct dir_context *ctx) ns = file->f_dentry->d_sb->s_fs_info; tid = (int)file->f_version; file->f_version = 0; - for (task = first_tid(leader, tid, ctx->pos - 2, ns); + for (task = first_tid(proc_pid(inode), tid, ctx->pos - 2, ns); task; task = next_tid(task), ctx->pos++) { char name[PROC_NUMBUF]; @@ -3197,8 +3194,7 @@ static int proc_task_readdir(struct file *file, struct dir_context *ctx) break; } } -out: - put_task_struct(leader); + return 0; } |