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move files_struct-related bits from kernel/exit.c to fs/file.c

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Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2012-08-15 19:56:12 -04:00
parent dcfadfa4ec
commit 7cf4dc3c8d
3 changed files with 99 additions and 100 deletions
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100
fs/file.c
View File

@ -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);

6
include/linux/fdtable.h
View File

@ -94,14 +94,8 @@ struct vfsmount;
struct dentry;
extern int expand_files(struct files_struct *, int nr);
extern void free_fdtable_rcu(struct rcu_head *rcu);
extern void __init files_defer_init(void);
static inline void free_fdtable(struct fdtable *fdt)
{
call_rcu(&fdt->rcu, free_fdtable_rcu);
}
static inline struct file * fcheck_files(struct files_struct *files, unsigned int fd)
{
struct file * file = NULL;

93
kernel/exit.c
View File

@ -466,99 +466,6 @@ void daemonize(const char *name, ...)
EXPORT_SYMBOL(daemonize);
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);
}
}
#ifdef CONFIG_MM_OWNER
/*
* A task is exiting. If it owned this mm, find a new owner for the mm.