Commit Graph

30728 Commits

Author SHA1 Message Date
NeilBrown a647e4bc5c [PATCH] md/bitmap: remove unnecessary page reference manipulations from md/bitmap code
md/bitmap gets a collection of pages representing the bitmap when it
initialises the bitmap, and puts all the references when discarding the
bitmap.

It also occasionally takes extra references without any good reason, and
sometimes drops them ...  though it doesn't always drop them, which can result
in a memory leak.

This patch removes the unnecessary 'get_page' calls, and the corresponding
'put_page' calls.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:38 -07:00
NeilBrown e16b68b6e4 [PATCH] md/bitmap: use set_bit etc for bitmap page attributes
In particular, this means that we use 4 bits per page instead of a whole
unsigned long.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:38 -07:00
NeilBrown ec7a3197f4 [PATCH] md/bitmap: cleaner separation of page attribute handlers in md/bitmap
md/bitmap has some attributes per-page.  Handling of these attributes in
largely abstracted in set_page_attr and clear_page_attr.  However
get_page_attr exposes the format used to store them.  So prior to changing
that format, introduce test_page_attr instead of get_page_attr, and make
appropriate usage changes.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:38 -07:00
NeilBrown 0b79ccf0cd [PATCH] md/bitmap: remove bitmap writeback daemon
md/bitmap currently has a separate thread to wait for writes to the bitmap
file to complete (as we cannot get a callback on that action).

However this isn't needed as bitmap_unplug is called from process context and
waits for the writeback thread to do it's work.  The same result can be
achieved by doing the waiting directly in bitmap_unplug.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:38 -07:00
NeilBrown d7375ab324 [PATCH] md/bitmap: fix online removal of file-backed bitmaps
When "mdadm --grow /dev/mdX --bitmap=none" is used to remove a filebacked
bitmap, the bitmap was disconnected from the array, but the file wasn't closed
(until the array was stopped).

The file also wasn't closed if adding the bitmap file failed.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:38 -07:00
NeilBrown 52c03291a8 [PATCH] md: split reshape portion of raid5 sync_request into a separate function
... as raid5 sync_request is WAY too big.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
Adrian Bunk 5e56341d02 [PATCH] md: make md_print_devices() static
This patch makes the needlessly global md_print_devices() static.

Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown c93983bf51 [PATCH] md: support stripe/offset mode in raid10
The "industry standard" DDF format allows for a stripe/offset layout where
data is duplicated on different stripes.  e.g.

  A  B  C  D
  D  A  B  C
  E  F  G  H
  H  E  F  G

(columns are drives, rows are stripes, LETTERS are chunks of data).

This is similar to raid10's 'far' mode, but not quite the same.  So enhance
'far' mode with a 'far/offset' option which follows the layout of DDFs
stripe/offset.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown 7c7546ccf6 [PATCH] md: allow a linear array to have drives added while active
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown 5fd6c1dce0 [PATCH] md: allow checkpoint of recovery with version-1 superblock
For a while we have had checkpointing of resync.  The version-1 superblock
allows recovery to be checkpointed as well, and this patch implements that.

Due to early carelessness we need to add a feature flag to signal that the
recovery_offset field is in use, otherwise older kernels would assume that a
partially recovered array is in fact fully recovered.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown a8a55c387d [PATCH] md: remove nuisance message at shutdown
At shutdown, we switch all arrays to read-only, which creates a message for
every instantiated array, even those which aren't actually active.

So remove the message for non-active arrays.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown 16a53ecc35 [PATCH] md: merge raid5 and raid6 code
There is a lot of commonality between raid5.c and raid6main.c.  This patches
merges both into one module called raid456.  This saves a lot of code, and
paves the way for online raid5->raid6 migrations.

There is still duplication, e.g.  between handle_stripe5 and handle_stripe6.
This will probably be cleaned up later.

Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown 16f17b39f3 [PATCH] md: increase the delay before marking metadata clean, and make it configurable
When a md array has been idle (no writes) for 20msecs it is marked as 'clean'.
 This delay turns out to be too short for some real workloads.  So increase it
to 200msec (the time to update the metadata should be a tiny fraction of that)
and make it sysfs-configurable.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:37 -07:00
NeilBrown 9443a1d1f7 [PATCH] md: remove useless ioctl warning
This warning was slightly useful back in 2.2 days, but is more an annoyance
now.  It makes it awkward to add new ioctls (that we we are likely to do that
in the current climate, but it is possible).

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:36 -07:00
NeilBrown 8932c2e0dc [PATCH] md: remove arbitrary limit on chunk size
The largest chunk size the code can support without substantial surgery is
2^30 bytes, so make that the limit instead of an arbitrary 4Meg.  Some day,
the 'chunksize' should change to a sector-shift instead of a byte-count.  Then
no limit would be needed.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:36 -07:00
NeilBrown c70810b327 [PATCH] md: reformat code in raid1_end_write_request to avoid goto
A recent change made this goto unnecessary, so reformat the code to make it
clearer what is happening.

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:36 -07:00
Alasdair G Kergon 72d9486169 [PATCH] dm: improve error message consistency
Tidy device-mapper error messages to include context information
automatically.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:36 -07:00
Alasdair G Kergon 5c6bd75d06 [PATCH] dm: prevent removal if open
If you misuse the device-mapper interface (or there's a bug in your userspace
tools) it's possible to end up with 'unlinked' mapped devices that cannot be
removed until you reboot (along with uninterruptible processes).

This patch prevents you from removing a device that is still open.

It introduces dm_lock_for_deletion() which is called when a device is about to
be removed to ensure that nothing has it open and nothing further can open it.
 It uses a private open_count for this which also lets us remove one of the
problematic bdget_disk() calls elsewhere.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:36 -07:00
David Teigland c2ade42dd3 [PATCH] dm: create error table
Add a library function dm_create_error_table() to create a table that rejects
any I/O sent to a device with EIO.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:36 -07:00
Alasdair G Kergon 17b2f66f2a [PATCH] dm: add exports
Move definitions of core device-mapper functions for manipulating mapped
devices and their tables to <linux/device-mapper.h> advertising their
availability for use elsewhere in the kernel.

Protect the contents of device-mapper.h with ifdef __KERNEL__.  And throw
in a few formatting clean-ups and extra comments.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:36 -07:00
Alasdair G Kergon 2b06cfff12 [PATCH] dm: consolidate creation functions
Merge dm_create() and dm_create_with_minor() by introducing the special value
DM_ANY_MINOR to request the allocation of the next available minor number.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:36 -07:00
David Teigland 814d68629b [PATCH] dm table split_args: handle no input
Return sense if dm_split_args is called with a NULL input parameter.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:36 -07:00
Jonathan Brassow ce503f59ae [PATCH] dm kcopyd: error accumulation fix
kcopyd should accumulate errors - otherwise I/O failures may be ignored
unintentionally.

And invert 'success' (used in a future patch), using a more intuitive
!(read_err || write_err).

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:35 -07:00
Alasdair G Kergon 8a835f11bc [PATCH] dm mirror log: sync_count fix
When a mirror is reduced in size, clear the part of the bitmap that is no
longer used.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:35 -07:00
Alasdair G Kergon 29121bd0b0 [PATCH] dm mirror log: bitset_size fix
Fix the 'sizeof' in the region log bitmap size calculation: it's uint32_t, not
unsigned long - this breaks on some archs.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:35 -07:00
Alasdair G Kergon b7cca195c4 [PATCH] dm mirror log: refactor context
Refactor the code that creates the core and disk log contexts to avoid the
repeated allocation of clean_bits introduced by the last patch.

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:35 -07:00
Kevin Corry 702ca6f0be [PATCH] dm mirror log: sector size fix
On-disk logs for dm-mirror devices are currently hard-coded to use 512 byte
hard-sector-sizes.  This patch fixes dm-log so it will work with devices with
non-512-byte hard-sector-sizes.

To maintain full compatibility, instead of moving the clean-bits bitset to a
bitset, and enlarges the disk-header buffer to encompass both the header and
the bitset.  The I/O routines for the bitset are removed, and the I/O routines
for the disk-header now also read/write the bitset.

Signed-off-by: Kevin Corry <kevcorry@us.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:35 -07:00
Milan Broz 143535396c [PATCH] dm table: get_target: fix last index
The table is indexed from 0, so an index equal to t->num_targets should be
rejected.

(There is no code in the current tree that would exercise this bug.)

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:35 -07:00
Neil Brown e4c8b3ba34 [PATCH] dm: mirror sector offset fix
The device-mapper core does not perform any remapping of bios before passing
them to the targets.  If a particular mapping begins part-way into a device,
targets obtain the sector relative to the start of the mapping by subtracting
ti->begin.

The dm-raid1 target didn't do this everywhere: this patch fixes it, taking
care to subtract ti->begin exactly once for each bio.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:35 -07:00
Jeff Mahoney f0b0411536 [PATCH] dm: fix block device initialisation
In alloc_dev(), we register the device with the block layer and then continue
to initialize the device.  But register_disk() makes the device available to
be opened before we have completed initialising it.

This patch moves the final bits of the initialization above the disk
registration.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:35 -07:00
Jeff Mahoney 10da4f795f [PATCH] dm: add module ref counting
The reference counting on dm-mod is zero if no mapped devices are open.  This
is incorrect, and can lead to an oops if the module is unloaded while mapped
devices exist.

This patch claims a reference to the module whenever a device is created, and
drops it again when the device is freed.

Devices must be removed before dm-mod is unloaded.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:35 -07:00
Jeff Mahoney 7ec75f2547 [PATCH] dm: fix mapped device ref counting
To avoid races, _minor_lock must be held while changing mapped device
reference counts.

There are a few paths where a mapped_device pointer is returned before a
reference is taken.  This patch fixes them.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:35 -07:00
Jeff Mahoney fba9f90e56 [PATCH] dm: add DMF_FREEING
There is a chicken and egg problem between the block layer and dm in which the
gendisk associated with a mapping keeps a reference-less pointer to the
mapped_device.

This patch uses a new flag DMF_FREEING to indicate when the mapped_device is
no longer valid.  This is checked to prevent any attempt to open the device
from succeeding while the device is being destroyed.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:34 -07:00
Jeff Mahoney f32c10b099 [PATCH] dm: change minor_lock to spinlock
While removing a device, another another thread might attempt to resurrect it.

This patch replaces the _minor_lock mutex with a spinlock and uses
atomic_dec_and_lock() to serialize reference counting in dm_put().

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:34 -07:00
Jeff Mahoney 62f75c2f32 [PATCH] dm: move idr_pre_get
idr_pre_get() can sleep while allocating memory.

The next patch will change _minor_lock into a spinlock, so this patch moves
idr_pre_get() outside the lock in preparation.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:34 -07:00
Jeff Mahoney ba61fdd17d [PATCH] dm: fix idr minor allocation
One part of the system can attempt to use a mapped device before another has
finished initialising it or while it is being freed.

This patch introduces a place holder value, MINOR_ALLOCED, to mark the minor
as allocated but in a state where it can't be used, such as mid-allocation or
mid-free.  At the end of the initialization, it replaces the place holder with
the pointer to the mapped_device, making it available to the rest of the dm
subsystem.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:34 -07:00
Jeff Mahoney 5806f07cd2 [PATCH] lib: add idr_replace
This patch adds idr_replace() to replace an existing pointer in a single
operation.

Device-mapper will use this to update the pointer it stored against a given
id.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:34 -07:00
Alasdair G Kergon c51c275249 [PATCH] dm snapshot: unify chunk_size
Persistent snapshots currently store a private copy of the chunk size.
Userspace also supplies the chunk size when loading a snapshot.  Ensure
consistency by only storing the chunk_size in one place instead of two.

Currently the two sizes will differ if the chunk size supplied by userspace
does not match the chunk size an existing snapshot actually uses.  Amongst
other problems, this causes an incorrect 'percentage full' to be reported.

The patch ensures consistency by only storing the chunk_size in one place,
removing it from struct pstore.  Some initialisation is delayed until the
correct chunk_size is known.  If read_header() discovers that the wrong chunk
size was supplied, the 'area' buffer (which the header already got read into)
is reinitialised to the correct size.

[akpm: too late for 2.6.17 - suitable for 2.6.17.x after it has settled]

Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:34 -07:00
Antonino A. Daplas b877a96409 [PATCH] VT binding: Make sticon support binding
Do not mark sticon_startup() as __init

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:34 -07:00
Antonino A. Daplas 2aea875da2 [PATCH] VT binding: Make promcon support binding
Do not mark promcon_startup() and promcon_init_unimap() as __init

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:34 -07:00
Antonino A. Daplas e86bb8acc0 [PATCH] VT binding: Make newport_con support binding
- move register ioremap from newport_startup() to newport_console_init()
- fonts are freed multiple times, do it only once

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:34 -07:00
Antonino A. Daplas ac08dae816 [PATCH] VT binding: Make mdacon support binding
Do not mark mdacon_startup __init.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:33 -07:00
Antonino A. Daplas 6690075d0b [PATCH] VT binding: Update documentation
Update Documentation/fb/fbcon.txt and Documentatin/console/console.txt to
reflect the following changes:

1. sysfs attributes are relocated to /sys/class/vtconsole

2. feature is selectable in Kconfig

3. add sample scripts to fbcon.txt

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:33 -07:00
Antonino A. Daplas 5bd42536b3 [PATCH] VT binding: Do not create a device file for class device 'fbcon'
The class device "fbcon" does not need to be a device file.  Do not create one
by passing a major and minor number of zero to
class_device_create()/destroy().

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:33 -07:00
Antonino A. Daplas 13ae664589 [PATCH] VT binding: Make VT binding a Kconfig option
To enable this feature, CONFIG_VT_HW_CONSOLE_BINDING must be set to 'y'.  This
feature will default to 'n' to minimize users accidentally corrupting their
virtual terminals.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:33 -07:00
Antonino A. Daplas 6db4063c5b [PATCH] VT binding: Add sysfs control to the VT layer
Add sysfs control to the VT layer.  A new sysfs class, 'vtconsole', and class
devices 'vtcon[n]' are added.  Each class device file has the following
attributes:

/sys/class/vtconsole/vtcon[n]/name - read-only attribute showing the
                                     name of the current backend

/sys/class/vtconsole/vtcon[n]/bind - read/write attribute
             where: 0 - backend is unbound/unbind backend from the VT layer
                    1 - backend is bound/bind backend to the VT layer

In addition, if any of the consoles are in KD_GRAPHICS mode, binding and
unbinding will not succeed.  KD_GRAPHICS mode usually indicates that the
underlying console hardware is used for other purposes other than displaying
text (ie X).  This feature should prevent binding/unbinding from interfering
with a graphics application using the VT.

[akpm@osdl.org: warning fixes]
Signed-off-by: Antonino Daplas <adaplas@pol.net>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:33 -07:00
Antonino A. Daplas 79062a0d39 [PATCH] VT binding: Add new doc file describing the feature
This newly added file will:

- Describe the characteristics of 2 general types of console drivers
- How to use the sysfs to unbind and bind console drivers
- Uses for this feature

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:33 -07:00
Antonino A. Daplas 418d1ce618 [PATCH] VT binding: fbcon: Update documentation
Update Documentation/fb/fbcon.txt to reflect the following changes:

1. Simple illustration of the binding of the console down to individual
   framebuffer drivers

2. Usage of userspace tools to help with recovery of text console

3. How to use the attributes in /sys/class/tty/console to unload fbcon and
   the framebuffer drivers

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:33 -07:00
Antonino A. Daplas e614b18dce [PATCH] VT binding: Update fbcon to support binding
The control for binding/unbinding is moved from fbcon to the console layer.
Thus the fbcon sysfs attributes, attach and detach, are also gone.

    1. Add a notifier event that tells fbcon if a framebuffer driver has been
       unregistered.  If no registered driver remains, fbcon will unregister
       itself from the console layer.

    2. Replaced calls to give_up_console() with unregister_con_driver().

    3. Still use take_over_console() instead of register_con_driver() to
       maintain compatibility

    4. Respect the parameter first_fb_vc and last_fb_vc instead of using 0 and
       MAX_NR_CONSOLES - 1. These parameters are settable by the user.

    5. When fbcon is completely unbound from the console layer, fbcon will
       also release (iow, decrement module reference counts to zero) all fbdev
       drivers. In other words, a bind or unbind request from the console layer
       will propagate down to the framebuffer drivers.

    6. If fbcon is not bound to the console, it will ignore all notifier
       events (except driver registration and unregistration) and all sysfs
       requests.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:33 -07:00
Antonino A. Daplas 3e795de763 [PATCH] VT binding: Add binding/unbinding support for the VT console
The framebuffer console is now able to dynamically bind and unbind from the VT
console layer.  Due to the way the VT console layer works, the drivers
themselves decide when to bind or unbind.  However, it was decided that
binding must be controlled, not by the drivers themselves, but by the VT
console layer.  With this, dynamic binding is possible for all VT console
drivers, not just fbcon.

Thus, the VT console layer will impose the following to all VT console
drivers:

- all registered VT console drivers will be entered in a private list
- drivers can register themselves to the VT console layer, but they cannot
  decide when to bind or unbind. (Exception: To maintain backwards
  compatibility, take_over_console() will automatically bind the driver after
  registration.)
- drivers can remove themselves from the list by unregistering from the VT
  console layer. A prerequisite for unregistration is that the driver must not
  be bound.

The following functions are new in the vt.c:

register_con_driver() - public function, this function adds the VT console
driver to an internal list maintained by the VT console

bind_con_driver() - private function, it binds the driver to the console

take_over_console() is changed to call register_con_driver() followed by a
bind_con_driver().  This is the only time drivers can decide when to bind to
the VT layer.  This is to maintain backwards compatibility.

unbind_con_driver() - private function, it unbinds the driver from its
console.  The vacated consoles will be taken over by the default boot console
driver.

unregister_con_driver() - public function, removes the driver from the
internal list maintained by the VT console.  It will only succeed if the
driver is currently unbound.

con_is_bound() checks if the driver is currently bound or not

give_up_console() is just a wrapper to unregister_con_driver().

There are also 3 additional functions meant to be called only by the tty layer
for sysfs control:

	vt_bind() - calls bind_con_driver()
	vt_unbind() - calls unbind_con_driver()
	vt_show_drivers() - shows the list of registered drivers

Most VT console drivers will continue to work as is, but might have problems
when unbinding or binding which should be fixable with minimal changes.

Signed-off-by: Antonino Daplas <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-26 09:58:33 -07:00