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14 commits

Author SHA1 Message Date
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
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
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
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
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