Changeset ed903174 in mainline for uspace/lib/libfs

Timestamp:

2010-02-10T23:51:23Z (15 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/libfs

Files:

• libfs.c (modified) (7 diffs)
• libfs.h (modified) (1 diff)

uspace/lib/libfs/libfs.c

@@ -37 +37 @@
 #include "libfs.h"
 #include "../../srv/vfs/vfs.h"
+#include <macros.h>
 #include <errno.h>
 #include <async.h>
@@ -398 +399 @@
                                                 ipc_answer_0(rid, rc);
                                         } else {
-                                                ipc_answer_5(rid, EOK,
-                                                    fs_handle, dev_handle,
+                                                aoff64_t size = ops->size_get(fn);
+                                                ipc_answer_5(rid, fs_handle,
+                                                    dev_handle,
                                                     ops->index_get(fn),
-                                                    ops->size_get(fn),
+                                                    LOWER32(size),
+                                                    UPPER32(size),
                                                     ops->lnkcnt_get(fn));
                                                 (void) ops->node_put(fn);
@@ -478 +481 @@
                                         ipc_answer_0(rid, rc);
                                 } else {
-                                        ipc_answer_5(rid, EOK,
-                                            fs_handle, dev_handle,
+                                        aoff64_t size = ops->size_get(fn);
+                                        ipc_answer_5(rid, fs_handle,
+                                            dev_handle,
                                             ops->index_get(fn),
-                                            ops->size_get(fn),
+                                            LOWER32(size),
+                                            UPPER32(size),
                                             ops->lnkcnt_get(fn));
                                         (void) ops->node_put(fn);
@@ -501 +506 @@
                 unsigned int old_lnkcnt = ops->lnkcnt_get(cur);
                 rc = ops->unlink(par, cur, component);
-                ipc_answer_5(rid, (ipcarg_t) rc, fs_handle, dev_handle,
-                    ops->index_get(cur), ops->size_get(cur), old_lnkcnt);
+                
+                if (rc == EOK) {
+                        aoff64_t size = ops->size_get(cur);
+                        ipc_answer_5(rid, fs_handle, dev_handle,
+                            ops->index_get(cur), LOWER32(size), UPPER32(size),
+                            old_lnkcnt);
+                } else
+                        ipc_answer_0(rid, rc);
+                
                 goto out;
         }
@@ -533 +545 @@
                         rc = ops->node_open(cur);
                 
-                ipc_answer_5(rid, rc, fs_handle, dev_handle,
-                    ops->index_get(cur), ops->size_get(cur),
-                    ops->lnkcnt_get(cur));
+                if (rc == EOK) {
+                        aoff64_t size = ops->size_get(cur);
+                        ipc_answer_5(rid, fs_handle, dev_handle,
+                            ops->index_get(cur), LOWER32(size), UPPER32(size),
+                            ops->lnkcnt_get(cur));
+                } else
+                        ipc_answer_0(rid, rc);
+                
         } else
                 ipc_answer_0(rid, rc);
@@ -602 +619 @@
         dev_handle_t dev_handle = IPC_GET_ARG1(*request);
         fs_index_t index = IPC_GET_ARG2(*request);
+        
         fs_node_t *fn;
-        int rc;
-        
-        rc = ops->node_get(&fn, dev_handle, index);
+        int rc = ops->node_get(&fn, dev_handle, index);
         on_error(rc, answer_and_return(rid, rc));
         
@@ -614 +630 @@
         
         rc = ops->node_open(fn);
-        ipc_answer_3(rid, rc, ops->size_get(fn), ops->lnkcnt_get(fn),
+        aoff64_t size = ops->size_get(fn);
+        ipc_answer_4(rid, rc, LOWER32(size), UPPER32(size), ops->lnkcnt_get(fn),
             (ops->is_file(fn) ? L_FILE : 0) | (ops->is_directory(fn) ? L_DIRECTORY : 0));
         

uspace/lib/libfs/libfs.h

@@ -76 +76 @@
          */
         fs_index_t (* index_get)(fs_node_t *);
-        size_t (* size_get)(fs_node_t *);
+        aoff64_t (* size_get)(fs_node_t *);
         unsigned int (* lnkcnt_get)(fs_node_t *);
         char (* plb_get_char)(unsigned pos);