get rid of fget_light()

instead of returning the flags by reference, we can just have the
low-level primitive return those in lower bits of unsigned long,
with struct file * derived from the rest.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2014-03-04 14:54:22 -05:00
parent 00e188ef6a
commit bd2a31d522
4 changed files with 56 additions and 39 deletions

View file

@ -683,35 +683,65 @@ 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, fmode_t mask, int *fput_needed)
static unsigned long __fget_light(unsigned int fd, fmode_t mask)
{
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 & mask))
file = NULL;
if (!file || unlikely(file->f_mode & mask))
return 0;
return (unsigned long)file;
} else {
file = __fget(fd, mask);
if (file)
*fput_needed = 1;
if (!file)
return 0;
return FDPUT_FPUT | (unsigned long)file;
}
return file;
}
struct file *fget_light(unsigned int fd, int *fput_needed)
unsigned long __fdget(unsigned int fd)
{
return __fget_light(fd, FMODE_PATH, fput_needed);
return __fget_light(fd, FMODE_PATH);
}
EXPORT_SYMBOL(fget_light);
EXPORT_SYMBOL(__fdget);
struct file *fget_raw_light(unsigned int fd, int *fput_needed)
unsigned long __fdget_raw(unsigned int fd)
{
return __fget_light(fd, 0, fput_needed);
return __fget_light(fd, 0);
}
unsigned long __fdget_pos(unsigned int fd)
{
struct files_struct *files = current->files;
struct file *file;
unsigned long v;
if (atomic_read(&files->count) == 1) {
file = __fcheck_files(files, fd);
v = 0;
} else {
file = __fget(fd, 0);
v = FDPUT_FPUT;
}
if (!file)
return 0;
if (file->f_mode & FMODE_ATOMIC_POS) {
if (file_count(file) > 1) {
v |= FDPUT_POS_UNLOCK;
mutex_lock(&file->f_pos_lock);
}
}
return v | (unsigned long)file;
}
/*
* We only lock f_pos if we have threads or if the file might be
* shared with another process. In both cases we'll have an elevated
* file count (done either by fdget() or by fork()).
*/
void set_close_on_exec(unsigned int fd, int flag)
{
struct files_struct *files = current->files;

View file

@ -264,23 +264,9 @@ loff_t vfs_llseek(struct file *file, loff_t offset, int whence)
}
EXPORT_SYMBOL(vfs_llseek);
/*
* We only lock f_pos if we have threads or if the file might be
* shared with another process. In both cases we'll have an elevated
* file count (done either by fdget() or by fork()).
*/
static inline struct fd fdget_pos(int fd)
{
struct fd f = fdget(fd);
struct file *file = f.file;
if (file && (file->f_mode & FMODE_ATOMIC_POS)) {
if (file_count(file) > 1) {
f.flags |= FDPUT_POS_UNLOCK;
mutex_lock(&file->f_pos_lock);
}
}
return f;
return __to_fd(__fdget_pos(fd));
}
static inline void fdput_pos(struct fd f)

View file

@ -40,23 +40,24 @@ static inline void fdput(struct fd fd)
}
extern struct file *fget(unsigned int fd);
extern struct file *fget_light(unsigned int fd, int *fput_needed);
extern struct file *fget_raw(unsigned int fd);
extern unsigned long __fdget(unsigned int fd);
extern unsigned long __fdget_raw(unsigned int fd);
extern unsigned long __fdget_pos(unsigned int fd);
static inline struct fd __to_fd(unsigned long v)
{
return (struct fd){(struct file *)(v & ~3),v & 3};
}
static inline struct fd fdget(unsigned int fd)
{
int b;
struct file *f = fget_light(fd, &b);
return (struct fd){f,b};
return __to_fd(__fdget(fd));
}
extern struct file *fget_raw(unsigned int fd);
extern struct file *fget_raw_light(unsigned int fd, int *fput_needed);
static inline struct fd fdget_raw(unsigned int fd)
{
int b;
struct file *f = fget_raw_light(fd, &b);
return (struct fd){f,b};
return __to_fd(__fdget_raw(fd));
}
extern int f_dupfd(unsigned int from, struct file *file, unsigned flags);

View file

@ -812,7 +812,7 @@ struct file {
#ifdef CONFIG_DEBUG_WRITECOUNT
unsigned long f_mnt_write_state;
#endif
};
} __attribute__((aligned(4))); /* lest something weird decides that 2 is OK */
struct file_handle {
__u32 handle_bytes;