Commit graph

29 commits

Author SHA1 Message Date
Boaz Harrosh
a49fb4c3d0 exofs: deprecate the commands pending counter
One leftover from the days of IBM's original code, is an SB counter
that counts in-flight asynchronous commands. And a piece of code that
waits for the counter to reach zero at unmount. I guess it might have
been needed then, cause of some reference missing or something.

I'm not removing it yet but am putting a warning message if ever this
counter triggers at unmount. If I'll never see it triggers or reported
I'll remove the counter for good.
(I had this print as a debug output for a long time and never had it
 trigger)

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-03-15 15:02:52 +02:00
Boaz Harrosh
1cea312ad4 exofs: Write sbi->s_nextid as part of the Create command
Before when creating a new inode, we'd set the sb->s_dirt flag,
and sometime later the system would write out s_nextid as part
of the sb_info. Also on inode sync we would force the sb sync
as well.

Define the s_nextid as a new partition attribute and set it
every time we create a new object.
At mount we read it from it's new place.

We now never set sb->s_dirt anywhere in exofs. write_super
is actually never called. The call to exofs_write_super from
exofs_put_super is also removed because the VFS always calls
->sync_fs before calling ->put_super twice.

To stay backward-and-forward compatible we also write the old
s_nextid in the super_block object at unmount, and support zero
length attribute on mount.

This also fixes a BUG where in layouts when group_width was not
a divisor of EXOFS_SUPER_ID (0x10000) the s_nextid was not read
from the device it was written to. Because of the sliding window
layout trick, and because the read was always done from the 0
device but the write was done via the raid engine that might slide
the device view. Now we read and write through the raid engine.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-03-15 15:02:51 +02:00
Boaz Harrosh
9ed9648431 exofs: Add option to mount by osdname
If /dev/osd* devices are shuffled because more devices
where added, and/or login order has changed. It is hard to
mount the FS you want.

Add an option to mount by osdname. osdname is any osd-device's
osdname as specified to the mkfs.exofs command when formatting
the osd-devices.
The new mount format is:
	OPT="osdname=$UUID0,pid=$PID,_netdev"
	mount -t exofs -o $OPT $DEV_OSD0 $MOUNTDIR

if "osdname=" is specified in options above $DEV_OSD0 is
ignored and can be empty.

Also while at it: Removed some old unused Opt_* enums.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-03-15 15:02:51 +02:00
bharrosh@panasas.com
66cd6cad49 exofs: Override read-ahead to align on stripe_size
* Set all inode->i_mapping->backing_dev_info to point to
  the per super-block sb->s_bdi.

* Calculating a read_ahead that is:
  - preferable 2 stripes long
    (Future patch will add a mount option to override this)
  - Minimum 128K aligned up to stripe-size
  - Caped to maximum-IO-sizes round down to stripe_size.
    (Max sizes are governed by max bio-size that fits in a page
     times number-of-devices)

CC: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2011-03-15 15:02:50 +02:00
Tobias Klauser
2c722c9a47 exofs: Remove redundant unlikely()
IS_ERR() already implies unlikely(), so it can be omitted here.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
2011-03-15 12:33:42 +02:00
Nick Piggin
fa0d7e3de6 fs: icache RCU free inodes
RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:26 +11:00
Al Viro
3c26ff6e49 convert get_sb_nodev() users
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:31 -04:00
Linus Torvalds
bf25db3654 Merge branch 'for-linus' of git://git.open-osd.org/linux-open-osd
* 'for-linus' of git://git.open-osd.org/linux-open-osd:
  exofs: Fix groups code when num_devices is not divisible by group_width
  exofs: Remove useless optimization
  exofs: exofs_file_fsync and exofs_file_flush correctness
  exofs: Remove superfluous dependency on buffer_head and writeback
2010-08-11 09:19:43 -07:00
Al Viro
4ec70c9b46 convert exofs to ->evict_inode()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:24 -04:00
Boaz Harrosh
85dc7878c6 exofs: Remove superfluous dependency on buffer_head and writeback
exofs_releasepage && exofs_invalidatepage are never called.
Leave the WARN_ONs but remove any code. Remove the

cleanup other stale #includes.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-08-04 13:17:55 +03:00
Jens Axboe
b3d0ab7e60 exofs: add bdi backing to mount session
This ensures that dirty data gets flushed properly.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-22 12:26:04 +02:00
Tejun Heo
5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Boaz Harrosh
50a76fd3c3 exofs: groups support
* _calc_stripe_info() changes to accommodate for grouping
  calculations. Returns additional information

* old _prepare_pages() becomes _prepare_one_group()
  which stores pages belonging to one device group.

* New _prepare_for_striping iterates on all groups calling
  _prepare_one_group().

* Enable mounting of groups data_maps (group_width != 0)

[QUESTION]
what is faster A or B;
A.	x += stride;
	x = x % width + first_x;

B	x += stride
	if (x < last_x)
		x = first_x;

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
2010-02-28 03:55:53 -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
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
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