Commit graph

11 commits

Author SHA1 Message Date
Ben Gras
bd3cde4571 Move primary cache code to libminixfs.
Add primary cache management feature to libminixfs as mfs and ext2
currently do separately, remove cache code from mfs and ext2, and make
them use the libminixfs interface. This makes all fields of the buf
struct private to libminixfs and FS clients aren't supposed to access
them at all. Only the opaque 'void *data' field (the FS block contents,
used to be called bp) is to be accessed by the FS client.

The main purpose is to implement the interface to the 2ndary vm cache
just once, get rid of some code duplication, and add a little
abstraction to reduce the code inertia of the whole caching business.

Some minor sanity checking and prohibition done by mfs in this code
as removed from the generic primary cache code as a result:
        - checking all inodes are not in use when allocating/resizing
          the cache
        - checking readonly filesystems aren't written to
        - checking the superblock isn't written to on mounted filesystems

The minixfslib code relies on fs_blockstats() in the client filesystem to
return some FS usage information.
2012-10-23 19:48:38 +02:00
David van Moolenbroek
5456f2728e ext2: resolve Coverity warnings 2012-08-14 09:11:19 +00:00
Thomas Veerman
6c597561bc EXT2: various fixes
.enable all compile time warnings and make them errors
.refactor functions with unused parameters
.fix null pointer dereference before checking for null
.proper variable initialization
.use safe string copy functions
.fix massive memory corruption bug in fs_getdents
2012-07-30 09:44:58 +00:00
Ben Gras
7336a67dfe retire PUBLIC, PRIVATE and FORWARD 2012-03-25 21:58:14 +02:00
Ben Gras
6a73e85ad1 retire _PROTOTYPE
. only good for obsolete K&R support
	. also remove a stray ansi.h and the proto cmd
2012-03-25 16:17:10 +02:00
David van Moolenbroek
b4d909d415 Split block/character protocols and libdriver
This patch separates the character and block driver communication
protocols. The old character protocol remains the same, but a new
block protocol is introduced. The libdriver library is replaced by
two new libraries: libchardriver and libblockdriver. Their exposed
API, and drivers that use them, have been updated accordingly.
Together, libbdev and libblockdriver now completely abstract away
the message format used by the block protocol. As the memory driver
is both a character and a block device driver, it now implements its
own message loop.

The most important semantic change made to the block protocol is that
it is no longer possible to return both partial results and an error
for a single transfer. This simplifies the interaction between the
caller and the driver, as the I/O vector no longer needs to be copied
back. Also, drivers are now no longer supposed to decide based on the
layout of the I/O vector when a transfer should be cut short. Put
simply, transfers are now supposed to either succeed completely, or
result in an error.

After this patch, the state of the various pieces is as follows:
- block protocol: stable
- libbdev API: stable for synchronous communication
- libblockdriver API: needs slight revision (the drvlib/partition API
  in particular; the threading API will also change shortly)
- character protocol: needs cleanup
- libchardriver API: needs cleanup accordingly
- driver restarts: largely unsupported until endpoint changes are
  reintroduced

As a side effect, this patch eliminates several bugs, hacks, and gcc
-Wall and -W warnings all over the place. It probably introduces a
few new ones, too.

Update warning: this patch changes the protocol between MFS and disk
drivers, so in order to use old/new images, the MFS from the ramdisk
must be used to mount all file systems.
2011-11-23 14:06:37 +01:00
David van Moolenbroek
af01bda509 libbdev: initial version
The "bdev" library provides basic primitives for file systems to talk
to block device drivers, hiding the details of the underlying protocol
and interaction model.

This version of libbdev is rather basic. It is planned to support the
following features in the long run:

 - asynchronous requests and replies;
 - recovery support for underlying block drivers;
 - retrying of failed I/O requests.

The commit also changes our block-based file systems (mfs, ext2, isofs)
to make use of libbdev.
2011-11-09 14:43:25 +01:00
Ben Gras
98233fa144 ext2: replace debug printf by assert 2011-09-09 16:33:55 +00:00
Ben Gras
4857d5d554 add -lminixfs with fs support routines
. move cache size heuristic from mfs there
	  so mfs and ext2 can share it
	. add vfs credentials retrieving function, with
	  backwards compatability from previous struct
	  format, to be used by both ext2 and mfs
	. fix for ext2 - STATICINIT was fed no.
	  of bytes instead of no. of elements, overallocating
	  memory by a megabyte or two for the superblock
2011-09-08 16:52:13 +00:00
Ben Gras
314d09adf7 fix clang warnings in servers/ 2011-05-12 22:23:02 +02:00
Thomas Veerman
dff0434eaf Add support for the ext2 file system. Contributed by Evgeniy Ivanov. 2010-08-02 11:44:45 +00:00