Changeset ed903174 in mainline for uspace/lib/libc/include/sys

Timestamp:

2010-02-10T23:51:23Z (16 years ago)

Author:

Martin Decky <martin@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

e70edd1

Parents:

b32c604f

Message:

implement support for 64bit file offsets

• the libc API is a small deviation from standard, but we have no reason to keep a strict backward compatibility with ancient code so far
  • the basic signed 64bit offset type is called off64_t
    • lseek() and fseek() take off64_t arguments (since the argument represents a relative offset)
    • ftell() returns off64_t values (since it is a wrapper of lseek())
    • vfs_seek() implementation supports negative offsets when SEEK_CUR and SEEK_END is used
  • aoff64_t is used for internal unsigned representation of sizes (in bytes, blocks, etc.) and absolute offsets
    • mmap() and ftruncate() take aoff64_t arguments (since the full range of the absolute file offset should be used here)
    • struct stat stores the file size as aoff64_t
  • in both cases the explicit range of the types shown in the names is helpful for proper filesystem and IPC interaction
  • note: size_t should be used only for representing in-memory sizes and offsets, not device and file-related information, and vice versa
    • the code base still needs a thorough revision with respect to this rule
  • PRIdOFF64 and PRIuOFF64 can be used for printing the offsets
• VFS_OUT_LOOKUP returns the 64bit file size in two IPC arguments
  • since all 5 IPC arguments have already been taken, the fs_handle is returned as the return value (fs_handle has only 16 bits, thus the return value can be used for both indicating errors as negative values and returning positive handles)
• VFS_OUT_READ and VFS_OUT_WRITE use aoff64_t absolute offsets split into two IPC arguments

replace bn_t with aoff64_t as a generic 64bit bytes/block counter type

note: filesystem drivers need to be revised with respect to make sure that all out-of-range checks are correct (especially w.r.t. file and block offsets)

Location:

uspace/lib/libc/include/sys

Files:

• mman.h (modified) (2 diffs)
• stat.h (modified) (2 diffs)
• typefmt.h (modified) (1 diff)
• types.h (modified) (1 diff)

uspace/lib/libc/include/sys/mman.h

@@ -41 +41 @@
 #define MAP_FAILED  ((void *) -1)
 
-#define MAP_SHARED       (1 << 0)
-#define MAP_PRIVATE      (1 << 1)
-#define MAP_FIXED        (1 << 2)
-#define MAP_ANONYMOUS    (1 << 3)
+#define MAP_SHARED     (1 << 0)
+#define MAP_PRIVATE    (1 << 1)
+#define MAP_FIXED      (1 << 2)
+#define MAP_ANONYMOUS  (1 << 3)
 
 #define PROTO_READ   AS_AREA_READ
@@ -50 +50 @@
 #define PROTO_EXEC   AS_AREA_EXEC
 
-extern void *mmap(void  *start, size_t length, int prot, int flags, int fd,
-    off_t offset);
+extern void *mmap(void *start, size_t length, int prot, int flags, int fd,
+    aoff64_t offset);
 extern int munmap(void *start, size_t length);
 

uspace/lib/libc/include/sys/stat.h

@@ -31 +31 @@
  */
 /** @file
- */ 
+ */
 
 #ifndef LIBC_SYS_STAT_H_
@@ -48 +48 @@
         bool is_file;
         bool is_directory;
-        off_t size;
+        aoff64_t size;
         dev_handle_t device;
 };

uspace/lib/libc/include/sys/typefmt.h

@@ -39 +39 @@
 #include <inttypes.h>
 
-/* off_t */
-#define PRIdOFF "ld"
-#define PRIuOFF "lu"
-#define PRIxOFF "lx"
-#define PRIXOFF "lX"
-
-/* bn_t */
-#define PRIdBN PRId64
-#define PRIuBN PRIu64
-#define PRIxBN PRIx64
-#define PRIXBN PRIX64
+/* off64_t */
+#define PRIdOFF64 PRId64
+#define PRIuOFF64 PRIu64
+#define PRIxOFF64 PRIx64
+#define PRIXOFF64 PRIX64
 
 /* (s)size_t */

uspace/lib/libc/include/sys/types.h

@@ -38 +38 @@
 #include <libarch/types.h>
 
-typedef long off_t;
-typedef int mode_t;
-typedef uint64_t bn_t;  /**< Block number type. */
+typedef unsigned int mode_t;
 
+/** Relative offset */
+typedef int64_t off64_t;
+
+/** Absolute offset */
+typedef uint64_t aoff64_t;
+
+/** Unicode code point */
 typedef int32_t wchar_t;