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>

diff --git a/fs/file.c b/fs/file.c
index db25c2bdfe464035be537cee3fc09acad77e8cdb..60a45e9f53231379c87b9ee75cb64eb8d6d71979 100644 (file)
--- a/fs/file.c
+++ b/fs/file.c
@@ -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;

diff --git a/fs/read_write.c b/fs/read_write.c
index 932bb3414a967a401edb671c9fc526b0f9e2dd55..54e19b9392dc74381fec154fe3f0ceab32ce9bd8 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -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)

diff --git a/include/linux/file.h b/include/linux/file.h
index f2517fa2d610524b9f887fb4fda11445220ffb1f..4d69123377a2b4e0a7869ba38cc91ceb4fd1c7b7 100644 (file)
--- a/include/linux/file.h
+++ b/include/linux/file.h
@@ -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 fdget(unsigned int fd)
+static inline struct fd __to_fd(unsigned long v)
 {
-       int b;
-       struct file *f = fget_light(fd, &b);
-       return (struct fd){f,b};
+       return (struct fd){(struct file *)(v & ~3),v & 3};
 }
 
-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(unsigned int fd)
+{
+       return __to_fd(__fdget(fd));
+}
 
 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);

diff --git a/include/linux/fs.h b/include/linux/fs.h
index ebfde04bca0683f1e2ecd2aa5c273b943eb7dfb9..23b2a35d712efbec3e31df0cae70b69a17b81616 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -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;