diff options
author | Al Viro <viro@zeniv.linux.org.uk> | 2012-08-15 19:56:12 -0400 |
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committer | Al Viro <viro@zeniv.linux.org.uk> | 2012-09-26 21:08:54 -0400 |
commit | 7cf4dc3c8dbfdfde163d4636f621cf99a1f63bfb (patch) | |
tree | 66ae2653acb5c5325cc4fc921bba53b6e6760983 /fs | |
parent | dcfadfa4ec5a12404a99ad6426871a6b03a62b37 (diff) | |
download | op-kernel-dev-7cf4dc3c8dbfdfde163d4636f621cf99a1f63bfb.zip op-kernel-dev-7cf4dc3c8dbfdfde163d4636f621cf99a1f63bfb.tar.gz |
move files_struct-related bits from kernel/exit.c to fs/file.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/file.c | 100 |
1 files changed, 99 insertions, 1 deletions
@@ -84,7 +84,7 @@ static void free_fdtable_work(struct work_struct *work) } } -void free_fdtable_rcu(struct rcu_head *rcu) +static void free_fdtable_rcu(struct rcu_head *rcu) { struct fdtable *fdt = container_of(rcu, struct fdtable, rcu); struct fdtable_defer *fddef; @@ -116,6 +116,11 @@ void free_fdtable_rcu(struct rcu_head *rcu) } } +static inline void free_fdtable(struct fdtable *fdt) +{ + call_rcu(&fdt->rcu, free_fdtable_rcu); +} + /* * Expand the fdset in the files_struct. Called with the files spinlock * held for write. @@ -388,6 +393,99 @@ out: return NULL; } +static void close_files(struct files_struct * files) +{ + int i, j; + struct fdtable *fdt; + + j = 0; + + /* + * It is safe to dereference the fd table without RCU or + * ->file_lock because this is the last reference to the + * files structure. But use RCU to shut RCU-lockdep up. + */ + rcu_read_lock(); + fdt = files_fdtable(files); + rcu_read_unlock(); + for (;;) { + unsigned long set; + i = j * BITS_PER_LONG; + if (i >= fdt->max_fds) + break; + set = fdt->open_fds[j++]; + while (set) { + if (set & 1) { + struct file * file = xchg(&fdt->fd[i], NULL); + if (file) { + filp_close(file, files); + cond_resched(); + } + } + i++; + set >>= 1; + } + } +} + +struct files_struct *get_files_struct(struct task_struct *task) +{ + struct files_struct *files; + + task_lock(task); + files = task->files; + if (files) + atomic_inc(&files->count); + task_unlock(task); + + return files; +} + +void put_files_struct(struct files_struct *files) +{ + struct fdtable *fdt; + + if (atomic_dec_and_test(&files->count)) { + close_files(files); + /* + * Free the fd and fdset arrays if we expanded them. + * If the fdtable was embedded, pass files for freeing + * at the end of the RCU grace period. Otherwise, + * you can free files immediately. + */ + rcu_read_lock(); + fdt = files_fdtable(files); + if (fdt != &files->fdtab) + kmem_cache_free(files_cachep, files); + free_fdtable(fdt); + rcu_read_unlock(); + } +} + +void reset_files_struct(struct files_struct *files) +{ + struct task_struct *tsk = current; + struct files_struct *old; + + old = tsk->files; + task_lock(tsk); + tsk->files = files; + task_unlock(tsk); + put_files_struct(old); +} + +void exit_files(struct task_struct *tsk) +{ + struct files_struct * files = tsk->files; + + if (files) { + task_lock(tsk); + tsk->files = NULL; + task_unlock(tsk); + put_files_struct(files); + } +} + static void __devinit fdtable_defer_list_init(int cpu) { struct fdtable_defer *fddef = &per_cpu(fdtable_defer_list, cpu); |