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Diffstat (limited to 'fs/file.c')
-rw-r--r--fs/file.c98
1 files changed, 29 insertions, 69 deletions
diff --git a/fs/file.c b/fs/file.c
index 4a78f981557a..771578b33fb6 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -348,21 +348,16 @@ out:
return NULL;
}
-static void close_files(struct files_struct * files)
+static struct fdtable *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.
+ * files structure.
*/
- rcu_read_lock();
- fdt = files_fdtable(files);
- rcu_read_unlock();
+ struct fdtable *fdt = rcu_dereference_raw(files->fdt);
+ int i, j = 0;
+
for (;;) {
unsigned long set;
i = j * BITS_PER_LONG;
@@ -381,6 +376,8 @@ static void close_files(struct files_struct * files)
set >>= 1;
}
}
+
+ return fdt;
}
struct files_struct *get_files_struct(struct task_struct *task)
@@ -398,14 +395,9 @@ struct files_struct *get_files_struct(struct task_struct *task)
void put_files_struct(struct files_struct *files)
{
- struct fdtable *fdt;
-
if (atomic_dec_and_test(&files->count)) {
- close_files(files);
- /* not really needed, since nobody can see us */
- rcu_read_lock();
- fdt = files_fdtable(files);
- rcu_read_unlock();
+ struct fdtable *fdt = close_files(files);
+
/* free the arrays if they are not embedded */
if (fdt != &files->fdtab)
__free_fdtable(fdt);
@@ -645,16 +637,16 @@ void do_close_on_exec(struct files_struct *files)
spin_unlock(&files->file_lock);
}
-struct file *fget(unsigned int fd)
+static struct file *__fget(unsigned int fd, fmode_t mask)
{
- struct file *file;
struct files_struct *files = current->files;
+ struct file *file;
rcu_read_lock();
file = fcheck_files(files, fd);
if (file) {
/* File object ref couldn't be taken */
- if (file->f_mode & FMODE_PATH ||
+ if ((file->f_mode & mask) ||
!atomic_long_inc_not_zero(&file->f_count))
file = NULL;
}
@@ -663,25 +655,16 @@ struct file *fget(unsigned int fd)
return file;
}
+struct file *fget(unsigned int fd)
+{
+ return __fget(fd, FMODE_PATH);
+}
EXPORT_SYMBOL(fget);
struct file *fget_raw(unsigned int fd)
{
- struct file *file;
- struct files_struct *files = current->files;
-
- rcu_read_lock();
- file = fcheck_files(files, fd);
- if (file) {
- /* File object ref couldn't be taken */
- if (!atomic_long_inc_not_zero(&file->f_count))
- file = NULL;
- }
- rcu_read_unlock();
-
- return file;
+ return __fget(fd, 0);
}
-
EXPORT_SYMBOL(fget_raw);
/*
@@ -700,56 +683,33 @@ EXPORT_SYMBOL(fget_raw);
* The fput_needed flag returned by fget_light should be passed to the
* corresponding fput_light.
*/
-struct file *fget_light(unsigned int fd, int *fput_needed)
+struct file *__fget_light(unsigned int fd, fmode_t mask, int *fput_needed)
{
- struct file *file;
struct files_struct *files = current->files;
+ struct file *file;
*fput_needed = 0;
if (atomic_read(&files->count) == 1) {
- file = fcheck_files(files, fd);
- if (file && (file->f_mode & FMODE_PATH))
+ file = __fcheck_files(files, fd);
+ if (file && (file->f_mode & mask))
file = NULL;
} else {
- rcu_read_lock();
- file = fcheck_files(files, fd);
- if (file) {
- if (!(file->f_mode & FMODE_PATH) &&
- atomic_long_inc_not_zero(&file->f_count))
- *fput_needed = 1;
- else
- /* Didn't get the reference, someone's freed */
- file = NULL;
- }
- rcu_read_unlock();
+ file = __fget(fd, mask);
+ if (file)
+ *fput_needed = 1;
}
return file;
}
+struct file *fget_light(unsigned int fd, int *fput_needed)
+{
+ return __fget_light(fd, FMODE_PATH, fput_needed);
+}
EXPORT_SYMBOL(fget_light);
struct file *fget_raw_light(unsigned int fd, int *fput_needed)
{
- struct file *file;
- struct files_struct *files = current->files;
-
- *fput_needed = 0;
- if (atomic_read(&files->count) == 1) {
- file = fcheck_files(files, fd);
- } else {
- rcu_read_lock();
- file = fcheck_files(files, fd);
- if (file) {
- if (atomic_long_inc_not_zero(&file->f_count))
- *fput_needed = 1;
- else
- /* Didn't get the reference, someone's freed */
- file = NULL;
- }
- rcu_read_unlock();
- }
-
- return file;
+ return __fget_light(fd, 0, fput_needed);
}
void set_close_on_exec(unsigned int fd, int flag)