27 Jun, 2006
40 commits
-
The md/dev-XXX/state file can now be written:
"faulty" simulates an error on the device
"remove" removes the device from the array (if it is not busy)Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This allows the state of an md/array to be directly controlled via sysfs and
adds the ability to stop and array without tearing it down.Array states/settings:
clear
No devices, no size, no level
Equivalent to STOP_ARRAY ioctl
inactive
May have some settings, but array is not active
all IO results in error
When written, doesn't tear down array, but just stops it
suspended (not supported yet)
All IO requests will block. The array can be reconfigured.
Writing this, if accepted, will block until array is quiescent
readonly
no resync can happen. no superblocks get written.
write requests fail
read-auto
like readonly, but behaves like 'clean' on a write request.clean - no pending writes, but otherwise active.
When written to inactive array, starts without resync
If a write request arrives then
if metadata is known, mark 'dirty' and switch to 'active'.
if not known, block and switch to write-pending
If written to an active array that has pending writes, then fails.
active
fully active: IO and resync can be happening.
When written to inactive array, starts with resyncwrite-pending (not supported yet)
clean, but writes are blocked waiting for 'active' to be written.active-idle
like active, but no writes have been seen for a while (100msec).Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
- record the 'event' count on each individual device (they
might sometimes be slightly different now)
- add a new value for 'sb_dirty': '3' means that the super
block only needs to be updated to record a cleandirty
transition.
- Prefer odd event numbers for dirty states and even numbers
for clean states
- Using all the above, don't update the superblock on
a spare device if the update is just doing a clean-dirty
transition. To accomodate this, a transition from
dirty back to clean might now decrement the events counter
if nothing else has changed.The net effect of this is that spare drives will not see any IO requests
during normal running of the array, so they can go to sleep if that is what
they want to do.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When an array has a bitmap, a device can be removed and re-added and only
blocks changes since the removal (as recorded in the bitmap) will be resynced.It should be possible to do a similar thing to arrays without bitmaps. i.e.
if a device is removed and re-added and *no* changes have been made in the
interim, then the add should not require a resync.This patch allows that option. This means that when assembling an array one
device at a time (e.g. during device discovery) the array can be enabled
read-only as soon as enough devices are available, but extra devices can still
be added without causing a resync.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
As data_disks is *less* than raid_disks, the current test here is obviously
wrong. And as the difference is already available in conf->max_degraded, it
makes much more sense to use that.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
RAID5 recently changed to RAID456
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
I was experimenting with Linux SW raid today and found a spelling error when
reading the help menus... (and fly spell found more).Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The size calculation made assumtion which the new offset mode didn't
follow. This gets the size right in all cases.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix problems with new bmap based access to bitmap files.
1/ When not using a file based bitmap, attach a NULL list of buffers
to each page so the common free_buffer routine can cope.
2/ Use submit_bh to read as well as write, rather than vfs_read.
This makes read and write more symetric.
3/ sync the file before reading, to ensure that the page cache has no
dirty pages that might get written out later.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If md is asked to store a bitmap in a file, it tries to hold onto the page
cache pages for that file, manipulate them directly, and call a cocktail of
operations to write the file out. I don't believe this is a supportable
approach.This patch changes the approach to use the same approach as swap files. i.e.
bmap is used to enumerate all the block address of parts of the file and we
write directly to those blocks of the device.swapfile only uses parts of the file that provide a full pages at contiguous
addresses. We don't have that luxury so we have to cope with pages that are
non-contiguous in storage. To handle this we attach buffers to each page, and
store the addresses in those buffers.With this approach the pagecache may contain data which is inconsistent with
what is on disk. To alleviate the problems this can cause, md invalidates the
pagecache when releasing the file. If the file is to be examined while the
array is active (a non-critical but occasionally useful function), O_DIRECT io
must be used. And new version of mdadm will have support for this.This approach simplifies a lot of code:
- we no longer need to keep a list of pages which we need to wait for,
as the b_endio function can keep track of how many outstanding
writes there are. This saves a mempool.
- -EAGAIN returns from write_page are no longer possible (not sure if
they ever were actually).Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
md/bitmap modifies i_writecount of a bitmap file to make sure that no-one else
writes to it. The reverting of the change is sometimes done twice, and there
is one error path where it is omitted.This patch tidies that up.
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
bitmap_active is never called, and the BITMAP_ACTIVE flag is never users or
tested, so discard them both.Also remove some out-of-date 'todo' comments.
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In particular, this means that we use 4 bits per page instead of a whole
unsigned long.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
... as raid5 sync_request is WAY too big.
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch makes the needlessly global md_print_devices() static.
Signed-off-by: Adrian Bunk
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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"
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
A recent change made this goto unnecessary, so reformat the code to make it
clearer what is happening.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Tidy device-mapper error messages to include context information
automatically.Signed-off-by: Alasdair G Kergon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Move definitions of core device-mapper functions for manipulating mapped
devices and their tables to 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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Return sense if dm_split_args is called with a NULL input parameter.
Signed-off-by: David Teigland
Signed-off-by: Alasdair G Kergon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Alasdair G Kergon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When a mirror is reduced in size, clear the part of the bitmap that is no
longer used.Signed-off-by: Alasdair G Kergon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Alasdair G Kergon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
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
Signed-off-by: Alasdair G Kergon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
