--- sys/sys/fcntl.h 2009-06-02 19:05:17.000000000 +0400 +++ sys/sys/fcntl.h 2009-09-22 16:28:52.000000000 +0400 @@ -132,7 +132,7 @@ /* bits to save after open */ #define FMASK (FREAD|FWRITE|FAPPEND|FASYNC|FFSYNC|FNONBLOCK|O_DIRECT) /* bits settable by fcntl(F_SETFL, ...) */ -#define FCNTLFLAGS (FAPPEND|FASYNC|FFSYNC|FNONBLOCK|FPOSIXSHM|O_DIRECT) +#define FCNTLFLAGS (FAPPEND|FASYNC|FFSYNC|FNONBLOCK|FPOSIXSHM|FRDAHEAD|O_DIRECT) #endif /* @@ -163,6 +163,9 @@ * implemented as plain files). */ #define FPOSIXSHM O_NOFOLLOW + +/* Read ahead */ +#define FRDAHEAD O_CREAT #endif /* @@ -187,6 +190,8 @@ #define F_SETLK 12 /* set record locking information */ #define F_SETLKW 13 /* F_SETLK; wait if blocked */ #define F_SETLK_REMOTE 14 /* debugging support for remote locks */ +#define F_READAHEAD 15 /* read ahead */ +#define F_RDAHEAD 16 /* Darwin compatible read ahead */ /* file descriptor flags (F_GETFD, F_SETFD) */ #define FD_CLOEXEC 1 /* close-on-exec flag */ --- sys/kern/vfs_vnops.c 2009-06-02 19:05:00.000000000 +0400 +++ sys/kern/vfs_vnops.c 2009-09-22 14:08:03.000000000 +0400 @@ -305,6 +305,9 @@ sequential_heuristic(struct uio *uio, struct file *fp) { + if (fp->f_flag & FRDAHEAD) + return(fp->f_seqcount << IO_SEQSHIFT); + if ((uio->uio_offset == 0 && fp->f_seqcount > 0) || uio->uio_offset == fp->f_nextoff) { /* --- sys/kern/kern_descrip.c 2009-08-28 18:50:11.000000000 +0400 +++ sys/kern/kern_descrip.c 2009-09-22 14:17:47.000000000 +0400 @@ -411,6 +411,7 @@ u_int newmin; int error, flg, tmp; int vfslocked; + uint64_t bsize; vfslocked = 0; error = 0; @@ -694,6 +695,35 @@ vfslocked = 0; fdrop(fp, td); break; + + case F_RDAHEAD: + arg = arg ? 128 * 1024: 0; + /* FALLTHROUGH */ + + case F_READAHEAD: + FILEDESC_SLOCK(fdp); + if ((fp = fdtofp(fd, fdp)) == NULL) { + FILEDESC_SUNLOCK(fdp); + error = EBADF; + break; + } + if (fp->f_type != DTYPE_VNODE) { + FILEDESC_SUNLOCK(fdp); + error = EBADF; + break; + } + FILE_LOCK(fp); + if (arg != 0) { + bsize = fp->f_vnode->v_mount->mnt_stat.f_iosize; + fp->f_seqcount = (arg + bsize - 1) / bsize; + fp->f_flag |= FRDAHEAD; + } else { + fp->f_flag &= ~FRDAHEAD; + } + FILE_UNLOCK(fp); + FILEDESC_SUNLOCK(fdp); + break; + default: error = EINVAL; break;