X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=lib%2Flfs.h;h=d4d4a60b2a0cff0af5e89270e97bc54f84742a61;hb=318a88602c0c1b46da4a5aea6d7f376c2fcd8829;hp=ab9d8e7188de3ddec612196278fd76246a674f00;hpb=824c295c7aebba96d28f8aaa9da317eca3e2225f;p=libucw.git

diff --git a/lib/lfs.h b/lib/lfs.h
index ab9d8e71..d4d4a60b 100644
--- a/lib/lfs.h
+++ b/lib/lfs.h
@@ -1,14 +1,43 @@
 /*
  *	Sherlock Library -- Large File Support
  *
- *	(c) 1999 Martin Mares, <mj@atrey.karlin.mff.cuni.cz>
+ *	(c) 1999--2001 Martin Mares <mj@ucw.cz>
  */
 
 #ifndef _SHERLOCK_LFS_H
 #define _SHERLOCK_LFS_H
 
+#include <fcntl.h>
+#include <unistd.h>
+
 #ifdef SHERLOCK_CONFIG_LFS
 
+#ifdef SHERLOCK_CONFIG_LFS_LIBC
+
+/*
+ *  Unfortunately, we need to configure this manually since
+ *  out-of-the-box glibc 2.1 offers the 64-bit calls, but
+ *  converts them to 32-bit syscalls. Damn it!
+ */
+
+#define sh_open open64
+#define sh_seek lseek64
+#define sh_pread pread64
+#define sh_pwrite pwrite64
+#define sh_ftruncate ftruncate64
+#define sh_mmap(a,l,p,f,d,o) mmap64(a,l,p,f,d,o)
+#define SHERLOCK_HAVE_PREAD
+
+#else
+
+#error Non-libc interface to LFS is currently broken, you have to fix it.
+
+/*
+ *  Talk directly with the kernel. The implementations of LFS in Linux 2.2
+ *  and 2.4 differ, but fortunately for us only in things like stat64 which
+ *  we don't need to use.
+ */
+
 #ifndef O_LARGEFILE
 #if defined(__linux__) && defined(__i386__)
 #define O_LARGEFILE 0100000
@@ -17,6 +46,12 @@
 #endif
 #endif
 
+static inline int
+sh_open(char *name, int flags, int mode)
+{
+  return open(name, flags | O_LARGEFILE, mode);
+}
+
 #if 0
 
 /* A "do it yourself" solution */
@@ -26,7 +61,7 @@
 
 _syscall5(int, _llseek, int, fd, int, hi, int, lo, loff_t *, result, int, whence);
 
-extern inline loff_t sh_seek(int fd, sh_off_t pos, int whence)
+static inline loff_t sh_seek(int fd, sh_off_t pos, int whence)
 {
   loff_t result;
   int err;
@@ -36,15 +71,76 @@ extern inline loff_t sh_seek(int fd, sh_off_t pos, int whence)
 }
 #else
 
+#if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ > 0
+/* glibc 2.1 or newer -> has lseek64 */
+#define sh_seek(f,o,w) lseek64(f,o,w)
+#else
 /* Touching hidden places in glibc */
 extern loff_t llseek(int fd, loff_t pos, int whence);
 #define sh_seek(f,o,w) llseek(f,o,w)
+#endif
 
 #endif
 
+#endif  /* !SHERLOCK_CONFIG_LFS_LIBC */
+
 #else	/* !SHERLOCK_CONFIG_LFS */
 
+#define sh_open open
 #define sh_seek(f,o,w) lseek(f,o,w)
+#define sh_ftruncate(f,o) ftruncate(f,o)
+#define sh_mmap(a,l,p,f,d,o) mmap(a,l,p,f,d,o)
 
 #endif	/* !SHERLOCK_CONFIG_LFS */
+
+/*
+ *  We'd like to use pread/pwrite for our file accesses, but unfortunately it
+ *  isn't simple at all since all libc's until glibc 2.1 don't define it.
+ */
+
+#ifndef SHERLOCK_HAVE_PREAD
+
+#ifdef __linux__
+#define SHERLOCK_HAVE_PREAD
+#if defined(__GLIBC__) && __GLIBC__ == 2 && __GLIBC_MINOR__ > 0
+/* glibc 2.1 or newer -> pread/pwrite supported automatically */
+#ifdef SHERLOCK_CONFIG_LFS
+/* but have to use the 64-bit versions explicitly */
+#define sh_pread pread64
+#define sh_pwrite pwrite64
+#else
+#define sh_pread pread
+#define sh_pwrite pwrite
+#endif
+#elif defined(i386) && defined(__GLIBC__)
+/* glibc 2.0 on i386 -> call syscalls directly */
+#include <asm/unistd.h>
+#include <syscall-list.h>
+#include <sys/types.h>
+#include <unistd.h>
+#ifndef SYS_pread
+#define SYS_pread 180
+#endif
+static int sh_pread(unsigned int fd, void *buf, size_t size, loff_t where)
+{ return syscall(SYS_pread, fd, buf, size, where); }
+#ifndef SYS_pwrite
+#define SYS_pwrite 181
+#endif
+static int sh_pwrite(unsigned int fd, void *buf, size_t size, loff_t where)
+{ return syscall(SYS_pwrite, fd, buf, size, where); }
+#elif defined(i386)
+/* old libc on i386 -> call syscalls directly the old way */
+#include <asm/unistd.h>
+#include <errno.h>
+static _syscall4(int, pread, unsigned int, fd, void *, buf, size_t, size, loff_t, where);
+static _syscall4(int, pwrite, unsigned int, fd, void *, buf, size_t, size, loff_t, where);
+#define sh_pread pread
+#define sh_pwrite pwrite
+#else
+#undef SHERLOCK_HAVE_PREAD
+#endif
+#endif	/* __linux__ */
+
+#endif  /* !SHERLOCK_HAVE_PREAD */
+
 #endif	/* !_SHERLOCK_LFS_H */