diff options
Diffstat (limited to 'include/linux/file.h')
| -rw-r--r-- | include/linux/file.h | 22 |
1 files changed, 16 insertions, 6 deletions
diff --git a/include/linux/file.h b/include/linux/file.h index 0f3f369f2450..eb28469b1c16 100644 --- a/include/linux/file.h +++ b/include/linux/file.h @@ -35,18 +35,28 @@ static inline void fput_light(struct file *file, int fput_needed) fput(file); } +/* either a reference to struct file + flags + * (cloned vs. borrowed, pos locked), with + * flags stored in lower bits of value, + * or empty (represented by 0). + */ struct fd { - struct file *file; - unsigned int flags; + unsigned long word; }; #define FDPUT_FPUT 1 #define FDPUT_POS_UNLOCK 2 -#define fd_file(f) ((f).file) +#define fd_file(f) ((struct file *)((f).word & ~(FDPUT_FPUT|FDPUT_POS_UNLOCK))) +static inline bool fd_empty(struct fd f) +{ + return unlikely(!f.word); +} + +#define EMPTY_FD (struct fd){0} static inline void fdput(struct fd fd) { - if (fd.flags & FDPUT_FPUT) + if (fd.word & FDPUT_FPUT) fput(fd_file(fd)); } @@ -60,7 +70,7 @@ extern void __f_unlock_pos(struct file *); static inline struct fd __to_fd(unsigned long v) { - return (struct fd){(struct file *)(v & ~3),v & 3}; + return (struct fd){v}; } static inline struct fd fdget(unsigned int fd) @@ -80,7 +90,7 @@ static inline struct fd fdget_pos(int fd) static inline void fdput_pos(struct fd f) { - if (f.flags & FDPUT_POS_UNLOCK) + if (f.word & FDPUT_POS_UNLOCK) __f_unlock_pos(fd_file(f)); fdput(f); } |