hurd/translator/tmpfs/notes_bing: New; retrieved from <http://www.superunprivileged.org/hurd/tmpfs_notes.txt>.

1 files changed, 82 insertions, 0 deletions

diff --git a/hurd/translator/tmpfs/notes_bing.mdwn b/hurd/translator/tmpfs/notes_bing.mdwn
new file mode 100644
index 00000000..b28611f2
--- /dev/null
+++ b/hurd/translator/tmpfs/notes_bing.mdwn
@@ -0,0 +1,82 @@
+1. to run tmpfs as a regular user, /servers/default-pager must be executable by that user.  by default it seems to be set to read/write.
+$ sudo chmod ugo+x /servers/default-pager
+
+Then I get this error:
+tmpfs: /build/mbanck/hurd-20060825/build-tree/hurd/tmpfs/dir.c:62: diskfs_get_directs: Assertion `__builtin_offsetof (struct tmpfs_dirent, name) >= __builtin_offsetof (struct dirent, d_name)' failed.
+
+2. i rearranged the struct tempfs_dirent in tmpfs.h to line up with the struct dirent.  now the assert passes at line 62 of dir.c passes.
+ struct tmpfs_dirent
+ {
+   struct tmpfs_dirent *next;
+   struct disknode *dn;
++  char padding[3];
+   uint8_t namelen;
+   char name[0];
+ };
+
+now ls works on an empty directory.
+you can touch files, and run `ls' on them.
+mkdir, rmdir works too.
+fsysopts works
+df works
+
+3. creating a symlink fails.
+
+old patch to get symlinks working:
+http://www.mail-archive.com/bug-hurd@gnu.org/msg11844.html
+--- node.c.orig 2005-07-24 09:56:39.000000000 -0400
++++ node.c      2005-07-24 09:55:46.000000000 -0400
+@@ -330,6 +330,7 @@
+ create_symlink_hook (struct node *np, const char *target)
+ {
+   assert (np->dn->u.lnk == 0);
++  np->dn_stat.st_size = strlen (target);
+   if (np->dn_stat.st_size > 0)
+     {
+       const size_t size = np->dn_stat.st_size + 1;
+@@ -337,6 +338,7 @@
+       if (np->dn->u.lnk == 0)
+        return ENOSPC;
+       memcpy (np->dn->u.lnk, target, size);
++      np->dn->type = DT_LNK;
+       adjust_used (size);
+       recompute_blocks (np);
+     }
+@@ -380,8 +382,6 @@
+ error_t
+ diskfs_truncate (struct node *np, off_t size)
+ {
+-  if (np->allocsize <= size)
+-    return 0;
+
+   if (np->dn->type == DT_LNK)
+     {
+@@ -392,6 +392,9 @@
+       return 0;
+     }
+
++  if (np->allocsize <= size)
++    return 0;
++
+   assert (np->dn->type == DT_REG);
+
+   if (default_pager == MACH_PORT_NULL)
+
+now symlinks work.
+
+4. can't write data to a file
+
+
+--
+miscellaneous notes:
+
+diskfs_disk_name could be NULL, but it is "swap"
+
+using default_pager_object_set_size (np->dn->u.reg.memobj, size); to truncate and grow.
+
+why are our blocks 512?  shouldn't it something else?  or at least settable?
+or does libdiskfs demand this?
+
+diskfs_get_filemap_pager_struct (struct node *np) returns null.
+shouldn't it return default_pager?
+---