Therefore, storing the value in the superblock and reading it out
again is silly and offers the opportunity for it to become corrupted.
So, don't do that (most of the code already didn't) and use the
existing constant instead. Initialize new 32-bit superblocks with
the value for the sake of old userland programs, but don't keep the
value in the 64-bit superblock at all.
(approved by Margo Seltzer)
(This part changes the native lfs code; the ufs-derived code already
has 64 vs. 32 logic, but as aspects of it are unsafe, and don't
entirely interoperate cleanly with the lfs 64/32 stuff, pass 2 will be
rehashing that.)
Add pieces of support for using both superblock types where
convenient, and specifically to the superblock accessors, but don't
actually enable it anywhere.
First substantive step on PR 50000.
This contains all the accessor functions and macros out of lfs.h.
Add an include of lfs_accessors.h after all uses of lfs.h... except
for code that wants to define its own struct lfs-alike that the
accessors are supposed to play along with. For these, set STRUCT_LFS
and include lfs_accessors.h after the necessary structure has been
defined, so that lfs_accessors.h can emit functions in terms of it.
superblock. This will allow switching between 32/64 bit forms on the
fly; it will also allow handling LFS_EI reasonably tidily. (That
currently doesn't work on the superblock.)
It also gets rid of cpp abuse in the form of fake structure member
macros.
Also, instead of doing sleep/wakeup on &lfs_avail and &lfs_nextseg
inside the on-disk superblock, add extra elements to the in-memory
struct lfs for this. (XXX: these should be changed to condvars, but
not right now)
XXX: this migrates a structure needed by the lfs code in libsa (struct
salfs) into lfs.h, where it doesn't belong, but for the time being
this is necessary in order to allow the accessors (and the various
lfs macros and other goop that relies on them) to compile.
This generates the same output (at least on amd64) but will be more
robust until we're ready to deploy lfs64 bootblocks too.
XXX: I don't think these actually work right now, and the logic for
picking between v1 and v2 lfs formats (which is not related to ffsv1
vs. ffsv2) is definitely broken. But I haven't made it any worse.
mrg