Commit Graph

40 Commits

Author SHA1 Message Date
Boaz Harrosh
86093aaff5 exofs: convert io_state to use pages array instead of bio at input
* inode.c operations are full-pages based, and not actually
  true scatter-gather
* Lets us use more pages at once upto 512 (from 249) in 64 bit
* Brings us much much closer to be able to use exofs's io_state engine
  from objlayout driver. (Once I decide where to put the common code)

After RAID0 patch the outer (input) bio was never used as a bio, but
was simply a page carrier into the raid engine. Even in the simple
mirror/single-dev arrangement pages info was copied into a second bio.
It is now easer to just pass a pages array into the io_state and prepare
bio(s) once.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28 03:44:42 -08:00
Boaz Harrosh
5d952b8391 exofs: RAID0 support
We now support striping over mirror devices. Including variable sized
stripe_unit.

Some limits:
* stripe_unit must be a multiple of PAGE_SIZE
* stripe_unit * stripe_count is maximum upto 32-bit (4Gb)

Tested RAID0 over mirrors, RAID0 only, mirrors only. All check.

Design notes:
* I'm not using a vectored raid-engine mechanism yet. Following the
  pnfs-objects-layout data-map structure, "Mirror" is just a private
  case of "group_width" == 1, and RAID0 is a private case of
  "Mirrors" == 1. The performance lose of the general case over the
  particular special case optimization is totally negligible, also
  considering the extra code size.

* In general I added a prepare_stripes() stage that divides the
  to-be-io pages to the participating devices, the previous
  exofs_ios_write/read, now becomes _write/read_mirrors and a new
  write/read upper layer loops on all devices calling
  _write/read_mirrors. Effectively the prepare_stripes stage is the all
  secret.
  Also truncate need fixing to accommodate for striping.

* In a RAID0 arrangement, in a regular usage scenario, if all inode
  layouts will start at the same device, the small files fill up the
  first device and the later devices stay empty, the farther the device
  the emptier it is.

  To fix that, each inode will start at a different stripe_unit,
  according to it's obj_id modulus number-of-stripe-units. And
  will then span all stripe-units in the same incrementing order
  wrapping back to the beginning of the device table. We call it
  a stripe-units moving window.

  Special consideration was taken to keep all devices in a mirror
  arrangement identical. So a broken osd-device could just be cloned
  from one of the mirrors and no FS scrubbing is needed. (We do that
  by rotating stripe-unit at a time and not a single device at a time.)

TODO:
 We no longer verify object_length == inode->i_size in exofs_iget.
 (since i_size is stripped on multiple objects now).
 I should introduce a multiple-device attribute reading, and use
 it in exofs_iget.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28 03:43:08 -08:00
Boaz Harrosh
d9c740d225 exofs: Define on-disk per-inode optional layout attribute
* Layouts describe the way a file is spread on multiple devices.
  The layout information is stored in the objects attribute introduced
  in this patch.

* There can be multiple generating function for the layout.
  Currently defined:
    - No attribute present - use below moving-window on global
      device table, all devices.
      (This is the only one currently used in exofs)
    - an obj_id generated moving window - the obj_id is a randomizing
      factor in the otherwise global map layout.
    - An explicit layout stored, including a data_map and a device
      index list.
    - More might be defined in future ...

* There are two attributes defined of the same structure:
  A-data-files-layout - This layout is used by data-files. If present
                        at a directory, all files of that directory will
                        be created with this layout.
  A-meta-data-layout - This layout is used by a directory and other
                       meta-data information. Also inherited at creation
                       of subdirectories.

* At creation time inodes are created with the layout specified above.
  A usermode utility may change the creation layout on a give directory
  or file. Which in the case of directories, will also apply to newly
  created files/subdirectories, children of that directory.
  In the simple unaltered case of a newly created exofs, no layout
  attributes are present, and all layouts adhere to the layout specified
  at the device-table.

* In case of a future file system loaded in an old exofs-driver.
  At iget(), the generating_function is inspected and if not supported
  will return an IO error to the application and the inode will not
  be loaded. So not to damage any data.
  Note: After this patch we do not yet support any type of layout
        only the RAID0 patch that enables striping at the super-block
        level will add support for RAID0 layouts above. This way we
        are past and future compatible and fully bisectable.

* Access to the device table is done by an accessor since
  it will change according to above information.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28 03:35:28 -08:00
Boaz Harrosh
46f4d973f6 exofs: unindent exofs_sbi_read
The original idea was that a mirror read can be sub-divided
to multiple devices. But this has very little gain and only
at very large IOes so it's not going to be implemented soon.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28 03:35:27 -08:00
Boaz Harrosh
45d3abcb1a exofs: Move layout related members to a layout structure
* Abstract away those members in exofs_sb_info that are related/needed
  by a layout into a new exofs_layout structure. Embed it in exofs_sb_info.

* At exofs_io_state receive/keep a pointer to an exofs_layout. No need for
  an exofs_sb_info pointer, all we need is at exofs_layout.

* Change any usage of above exofs_sb_info members to their new name.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28 03:35:27 -08:00
Boaz Harrosh
22ddc55638 exofs: Recover in the case of read-passed-end-of-file
In check_io, implement the case of reading passed end of
file, by clearing the pages and recover with no error. In
a raid arrangement this can become a legitimate situation
in case of holes in the file.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28 03:35:26 -08:00
Boaz Harrosh
518f167a37 exofs: Micro-optimize exofs_i_info
optimize the exofs_i_info struct usage by moving the embedded
vfs_inode to be first. A compiler might optimize away an "add"
operation with constant zero. (Which it cannot with other constants)

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28 03:35:25 -08:00
Boaz Harrosh
34ce4e7c23 exofs: debug print even less
* Last debug trimming left in some stupid print, remove them.
  Fixup some other prints
* Shift printing from inode.c to ios.c
* Add couple of prints when memory allocation fails.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28 03:35:25 -08:00
Boaz Harrosh
efd124b999 exofs: simple_write_end does not mark_inode_dirty
exofs uses simple_write_end() for it's .write_end handler. But
it is not enough because simple_write_end() does not call
mark_inode_dirty() when it extends i_size. So even if we do
call mark_inode_dirty at beginning of write out, with a very
long IO and a saturated system we might get the .write_inode()
called while still extend-writing to file and miss out on the last
i_size updates.

So override .write_end, call simple_write_end(), and afterwords if
i_size was changed call mark_inode_dirty().

It stands to logic that since simple_write_end() was the one extending
i_size it should also call mark_inode_dirty(). But it looks like all
users of simple_write_end() are memory-bound pseudo filesystems, who
could careless about mark_inode_dirty(). I might submit a
warning-comment patch to simple_write_end() in future.

CC: Stable <stable@kernel.org>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-01-05 09:14:32 +02:00
Boaz Harrosh
89be503021 exofs: fix pnfs_osd re-definitions in pre-pnfs trees
Some on disk exofs constants and types are defined in the pnfs_osd_xdr.h
file. Since we needed these types before the pnfs-objects code was
accepted to mainline we duplicated the minimal needed definitions into
an exofs local header. The definitions where conditionally included
depending on !CONFIG_PNFS defined. So if PNFS was present in the tree
definitions are taken from there and if not they are defined locally.

That was all good but, the CONFIG_PNFS is planed to be included upstream
before the pnfs-objects is also included. (The first pnfs batch might be
pnfs-files only)

So condition exofs local definitions on the absence of pnfs_osd_xdr.h
inclusion (__PNFS_OSD_XDR_H__ not defined). User code must make sure
that in future pnfs_osd_xdr.h will be included before fs/exofs/pnfs.h,
which happens to be so in current code.

Once pnfs-objects hits mainline, exofs's local header will be removed.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-01-05 09:14:32 +02:00
Boaz Harrosh
04dc1e88ad exofs: Multi-device mirror support
This patch changes on-disk format, it is accompanied with a parallel
patch to mkfs.exofs that enables multi-device capabilities.

After this patch, old exofs will refuse to mount a new formatted FS and
new exofs will refuse an old format. This is done by moving the magic
field offset inside the FSCB. A new FSCB *version* field was added. In
the future, exofs will refuse to mount unmatched FSCB version. To
up-grade or down-grade an exofs one must use mkfs.exofs --upgrade option
before mounting.

Introduced, a new object that contains a *device-table*. This object
contains the default *data-map* and a linear array of devices
information, which identifies the devices used in the filesystem. This
object is only written to offline by mkfs.exofs. This is why it is kept
separate from the FSCB, since the later is written to while mounted.

Same partition number, same object number is used on all devices only
the device varies.

* define the new format, then load the device table on mount time make
  sure every thing is supported.

* Change I/O engine to now support Mirror IO, .i.e write same data
  to multiple devices, read from a random device to spread the
  read-load from multiple clients (TODO: stripe read)

Implementation notes:
 A few points introduced in previous patch should be mentioned here:

* Special care was made so absolutlly all operation that have any chance
  of failing are done before any osd-request is executed. This is to
  minimize the need for a data consistency recovery, to only real IO
  errors.

* Each IO state has a kref. It starts at 1, any osd-request executed
  will increment the kref, finally when all are executed the first ref
  is dropped. At IO-done, each request completion decrements the kref,
  the last one to return executes the internal _last_io() routine.
  _last_io() will call the registered io_state_done. On sync mode a
  caller does not supply a done method, indicating a synchronous
  request, the caller is put to sleep and a special io_state_done is
  registered that will awaken the caller. Though also in sync mode all
  operations are executed in parallel.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10 09:59:23 +02:00
Boaz Harrosh
06886a5a3d exofs: Move all operations to an io_engine
In anticipation for multi-device operations, we separate osd operations
into an abstract I/O API. Currently only one device is used but later
when adding more devices, we will drive all devices in parallel according
to a "data_map" that describes how data is arranged on multiple devices.
The file system level operates, like before, as if there is one object
(inode-number) and an i_size. The io engine will split this to the same
object-number but on multiple device.

At first we introduce Mirror (raid 1) layout. But at the final outcome
we intend to fully implement the pNFS-Objects data-map, including
raid 0,4,5,6 over mirrored devices, over multiple device-groups. And
more. See: http://tools.ietf.org/html/draft-ietf-nfsv4-pnfs-obj-12

* Define an io_state based API for accessing osd storage devices
  in an abstract way.
  Usage:
	First a caller allocates an io state with:
		exofs_get_io_state(struct exofs_sb_info *sbi,
				   struct exofs_io_state** ios);

	Then calles one of:
		exofs_sbi_create(struct exofs_io_state *ios);
		exofs_sbi_remove(struct exofs_io_state *ios);
		exofs_sbi_write(struct exofs_io_state *ios);
		exofs_sbi_read(struct exofs_io_state *ios);
		exofs_oi_truncate(struct exofs_i_info *oi, u64 new_len);

	And when done
		exofs_put_io_state(struct exofs_io_state *ios);

* Convert all source files to use this new API
* Convert from bio_alloc to bio_kmalloc
* In io engine we make use of the now fixed osd_req_decode_sense

There are no functional changes or on disk additions after this patch.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10 09:59:22 +02:00
Boaz Harrosh
8ce9bdd1fb exofs: move osd.c to ios.c
If I do a "git mv" together with a massive code change
and commit in one patch, git looses the rename and
records a delete/new instead. This is bad because I want
a rename recorded so later rebased/cherry-picked patches
to the old name will work. Also the --follow is lost.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10 09:59:21 +02:00
Boaz Harrosh
cae012d853 exofs: statfs blocks is sectors not FS blocks
Even though exofs has a 4k block size, statfs blocks
is in sectors (512 bytes).

Also if target returns 0 for capacity then make it
ULLONG_MAX. df does not like zero-size filesystems

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10 09:59:21 +02:00
Boaz Harrosh
19fe294f2e exofs: Prints on mount and unmout
It is important to print in the logs when a filesystem was
mounted and eventually unmounted.

Print the osd-device's osd_name and pid the FS was
mounted/unmounted on.

TODO: How to also print the namespace path the filesystem was
      mounted on?

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10 09:59:20 +02:00
Boaz Harrosh
9cfdc7aa9f exofs: refactor exofs_i_info initialization into common helper
There are two places that initialize inodes: exofs_iget() and
exofs_new_inode()

As more members of exofs_i_info that need initialization are
added this code will grow. (soon)

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10 09:59:19 +02:00
Boaz Harrosh
fe33cc1ee1 exofs: dbg-print less
Iner-loops printing is converted to EXOFS_DBG2 which is #defined
to nothing.

It is now almost bareable to just leave debug-on. Every operation
is printed once, with most relevant info (I hope).

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10 09:59:18 +02:00
Boaz Harrosh
58311c43df exofs: More sane debug print
debug prints should be somewhat useful without actually
reading the source code

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-12-10 09:59:17 +02:00
Boaz Harrosh
1ba50bbe93 exofs: remove BKL from super operations
the two places inside exofs that where taking the BKL were:
exofs_put_super() - .put_super
and
exofs_sync_fs() - which is .sync_fs and is also called from
                  .write_super.

Now exofs_sync_fs() is protected from itself by also taking
the sb_lock.

exofs_put_super() directly calls exofs_sync_fs() so there is no
danger between these two either.

In anyway there is absolutely nothing dangerous been done
inside exofs_sync_fs().

Unless there is some subtle race with the actual lifetime of
the super_block in regard to .put_super and some other parts
of the VFS. Which is highly unlikely.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-09-24 07:47:38 -04:00
Alexey Dobriyan
405f55712d headers: smp_lock.h redux
* Remove smp_lock.h from files which don't need it (including some headers!)
* Add smp_lock.h to files which do need it
* Make smp_lock.h include conditional in hardirq.h
  It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT

  This will make hardirq.h inclusion cheaper for every PREEMPT=n config
  (which includes allmodconfig/allyesconfig, BTW)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-12 12:22:34 -07:00
Boaz Harrosh
baaf94cdc7 exofs: Avoid using file_fsync()
The use of file_fsync() in exofs_file_sync() is not necessary since it
does some extra stuff not used by exofs. Open code just the parts that
are currently needed.

TODO: Farther optimization can be done to sync the sb only on inode
update of new files, Usually the sb update is not needed in exofs.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-06-21 17:53:47 +03:00
Boaz Harrosh
27d2e14919 exofs: Remove IBM copyrights
Boaz,
Congrats on getting all the OSD stuff into 2.6.30!
I just pulled the git, and saw that the IBM copyrights are still there.
Please remove them from all files:
 * Copyright (C) 2005, 2006
 * International Business Machines

IBM has revoked all rights on the code - they gave it to me.

Thanks!
Avishay

Signed-off-by: Avishay Traeger <avishay@gmail.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-06-21 17:53:47 +03:00
Boaz Harrosh
b76a3f93d0 exofs: Fix bio leak in error handling path (sync read)
When failing a read request in the sync path, called from
write_begin, I forgot to free the allocated bio, fix it.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-06-21 17:53:44 +03:00
James Bottomley
82681a318f [SCSI] Merge branch 'linus'
Conflicts:
	drivers/message/fusion/mptsas.c

fixed up conflict between req->data_len accessors and mptsas driver updates.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-06-12 10:02:03 -05:00
Christoph Hellwig
80e09fb942 exofs: add ->sync_fs
Add a ->sync_fs method for data integrity syncs, and reimplement
->write_super ontop of it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:15 -04:00
Christoph Hellwig
ebc1ac1645 ->write_super lock_super pushdown
Push down lock_super into ->write_super instances and remove it from the
caller.

Following filesystem don't need ->s_lock in ->write_super and are skipped:

 * bfs, nilfs2 - no other uses of s_lock and have internal locks in
	->write_super
 * ext2 - uses BKL in ext2_write_super and has internal calls without s_lock
 * reiserfs - no other uses of s_lock as has reiserfs_write_lock (BKL) in
 	->write_super
 * xfs - no other uses of s_lock and uses internal lock (buffer lock on
	superblock buffer) to serialize ->write_super.  Also xfs_fs_write_super
	is superflous and will go away in the next merge window

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:09 -04:00
Christoph Hellwig
6cfd014842 push BKL down into ->put_super
Move BKL into ->put_super from the only caller.  A couple of
filesystems had trivial enough ->put_super (only kfree and NULLing of
s_fs_info + stuff in there) to not get any locking: coda, cramfs, efs,
hugetlbfs, omfs, qnx4, shmem, all others got the full treatment.  Most
of them probably don't need it, but I'd rather sort that out individually.
Preferably after all the other BKL pushdowns in that area.

[AV: original used to move lock_super() down as well; these changes are
removed since we don't do lock_super() at all in generic_shutdown_super()
now]
[AV: fuse, btrfs and xfs are known to need no damn BKL, exempt]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:07 -04:00
Christoph Hellwig
8c85e12512 remove ->write_super call in generic_shutdown_super
We just did a full fs writeout using sync_filesystem before, and if
that's not enough for the filesystem it can perform it's own writeout
in ->put_super, which many filesystems already do.

Move a call to foofs_write_super into every foofs_put_super for now to
guarantee identical behaviour until it's cleaned up by the individual
filesystem maintainers.

Exceptions:

 - affs already has identical copy & pasted code at the beginning of
   affs_put_super so no need to do it twice.
 - xfs does the right thing without it and I have changes pending for
   the xfs tree touching this are so I don't really need conflicts
   here..

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11 21:36:06 -04:00
Boaz Harrosh
fc2fac5b5f [SCSI] libosd: Define an osd_dev wrapper to retrieve the request_queue
libosd users that need to work with bios, must sometime use
the request_queue associated with the osd_dev. Make a wrapper for
that, and convert all in-tree users.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-06-10 09:00:13 -05:00
Boaz Harrosh
62f469b596 [SCSI] libosd: osd_req_{read,write} takes a length parameter
For supporting of chained-bios we can not inspect the first
bio only, as before. Caller shall pass the total length of the
request, ie. sum_bytes(bio-chain).

Also since the bio might be a chain we don't set it's direction
on behalf of it's callers. The bio direction should be properly
set prior to this call. So fix a couple of write users that now
need to set the bio direction properly

[In this patch I change both library code and user sites at
 exofs, to make it easy on integration. It should be submitted
 via James's scsi-misc tree.]

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
CC: Jeff Garzik <jeff@garzik.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-06-10 08:59:52 -05:00
Boaz Harrosh
0e35afbc8b [SCSI] libosd: osd_req_{read,write}_kern new API
By popular demand, define usefull wrappers for osd_req_read/write
that recieve kernel pointers. All users had their own.

Also remove these from exofs

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-06-10 08:57:07 -05:00
Tejun Heo
c3a4d78c58 block: add rq->resid_len
rq->data_len served two purposes - the length of data buffer on issue
and the residual count on completion.  This duality creates some
headaches.

First of all, block layer and low level drivers can't really determine
what rq->data_len contains while a request is executing.  It could be
the total request length or it coulde be anything else one of the
lower layers is using to keep track of residual count.  This
complicates things because blk_rq_bytes() and thus
[__]blk_end_request_all() relies on rq->data_len for PC commands.
Drivers which want to report residual count should first cache the
total request length, update rq->data_len and then complete the
request with the cached data length.

Secondly, it makes requests default to reporting full residual count,
ie. reporting that no data transfer occurred.  The residual count is
an exception not the norm; however, the driver should clear
rq->data_len to zero to signify the normal cases while leaving it
alone means no data transfer occurred at all.  This reverse default
behavior complicates code unnecessarily and renders block PC on some
drivers (ide-tape/floppy) unuseable.

This patch adds rq->resid_len which is used only for residual count.

While at it, remove now unnecessasry blk_rq_bytes() caching in
ide_pc_intr() as rq->data_len is not changed anymore.

Boaz	: spotted missing conversion in osd
Sergei	: spotted too early conversion to blk_rq_bytes() in ide-tape

[ Impact: cleanup residual count handling, report 0 resid by default ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Borislav Petkov <petkovbb@googlemail.com>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Doug Gilbert <dgilbert@interlog.com>
Cc: Mike Miller <mike.miller@hp.com>
Cc: Eric Moore <Eric.Moore@lsi.com>
Cc: Darrick J. Wong <djwong@us.ibm.com>
Cc: Pete Zaitcev <zaitcev@redhat.com>
Cc: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-11 09:50:53 +02:00
Boaz Harrosh
214c8adb87 exofs: Documentation
Added some documentation in exofs.txt, as well as a BUGS file.

For further reading, operation instructions, example scripts
and up to date infomation and code please see:
http://open-osd.org

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31 19:44:38 +03:00
Boaz Harrosh
8cf74b3936 exofs: export_operations
implement export_operations and set in superblock.
It is now posible to export exofs via nfs

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31 19:44:36 +03:00
Boaz Harrosh
ba9e5e98ca exofs: super_operations and file_system_type
This patch ties all operation vectors into a file system superblock
and registers the exofs file_system_type at module's load time.

* The file system control block (AKA on-disk superblock) resides in
  an object with a special ID (defined in common.h).
  Information included in the file system control block is used to
  fill the in-memory superblock structure at mount time. This object
  is created before the file system is used by mkexofs.c It contains
  information such as:
	- The file system's magic number
	- The next inode number to be allocated

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31 19:44:34 +03:00
Boaz Harrosh
e6af00f1d1 exofs: dir_inode and directory operations
implementation of directory and inode operations.

* A directory is treated as a file, and essentially contains a list
  of <file name, inode #> pairs for files that are found in that
  directory. The object IDs correspond to the files' inode numbers
  and are allocated using a 64bit incrementing global counter.
* Each file's control block (AKA on-disk inode) is stored in its
  object's attributes. This applies to both regular files and other
  types (directories, device files, symlinks, etc.).

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31 19:44:31 +03:00
Boaz Harrosh
beaec07ba6 exofs: address_space_operations
OK Now we start to read and write from osd-objects. We try to
collect at most contiguous pages as possible in a single write/read.
The first page index is the object's offset.

TODO:
   In 64-bit a single bio can carry at most 128 pages.
   Add support of chaining multiple bios

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31 19:44:29 +03:00
Boaz Harrosh
982980d753 exofs: symlink_inode and fast_symlink_inode operations
Generic implementation of symlink ops.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31 19:44:27 +03:00
Boaz Harrosh
e806271916 exofs: file and file_inode operations
implementation of the file_operations and inode_operations for
regular data files.

Most file_operations are generic vfs implementations except:
- exofs_truncate will truncate the OSD object as well
- Generic file_fsync is not good for none_bd devices so open code it
- The default for .flush in Linux is todo nothing so call exofs_fsync
  on the file.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31 19:44:24 +03:00
Boaz Harrosh
b14f8ab284 exofs: Kbuild, Headers and osd utils
This patch includes osd infrastructure that will be used later by
the file system.

Also the declarations of constants, on disk structures,
and prototypes.

And the Kbuild+Kconfig files needed to build the exofs module.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2009-03-31 19:44:20 +03:00