02 Mar, 2007
1 commit
-
There are two errors that can lead to recovery problems with raid10
when used in 'far' more (not the default).Due to a '>' instead of '>=' the wrong block is located which would result in
garbage being written to some random location, quite possible outside the
range of the device, causing the newly reconstructed device to fail.The device size calculation had some rounding errors (it didn't round when it
should) and so recovery would go a few blocks too far which would again cause
a write to a random block address and probably a device error.The code for working with device sizes was fairly confused and spread out, so
this has been tided up a bit.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
12 Jan, 2007
1 commit
-
md raidX make_request functions strip off the BIO_RW_SYNC flag, thus
introducing additional latency.Fixing this in raid1 and raid10 seems to be straightforward enough.
For our particular usage case in DRBD, passing this flag improved some
initialization time from ~5 minutes to ~5 seconds.Acked-by: NeilBrown
Signed-off-by: Lars Ellenberg
Acked-by: Jens Axboe
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
14 Dec, 2006
1 commit
-
Thanks Jens for alerting me to this.
Cc: Jens Axboe
Cc:
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Oct, 2006
1 commit
-
drivers/md/raid1.c:1479: warning: long long unsigned int format, long unsigned int arg (arg 4)
drivers/md/raid10.c:1475: warning: long long unsigned int format, long unsigned int arg (arg 4)Signed-off-by: Randy Dunlap
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Oct, 2006
1 commit
-
Two less-used md personalities have bugs in the calculation of ->degraded (the
extent to which the array is degraded).Signed-off-by: Neil Brown
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Oct, 2006
5 commits
-
raid1, raid10 and multipath don't report their 'congested' status through
bdi_*_congested, but should.This patch adds the appropriate functions which just check the 'congested'
status of all active members (with appropriate locking).raid1 read_balance should be modified to prefer devices where
bdi_read_congested returns false. Then we could use the '&' branch rather
than the '|' branch. However that should would need some benchmarking first
to make sure it is actually a good idea.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The error handling routines don't use proper locking, and so two concurrent
errors could trigger a problem.So:
- use test-and-set and test-and-clear to synchonise
the In_sync bits with the ->degraded count
- use the spinlock to protect updates to the
degraded count (could use an atomic_t but that
would be a bigger change in code, and isn't
really justified)
- remove un-necessary locking in raid5Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
It isn't needed as mddev->degraded contains equivalent info.
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Instead of magic numbers (0,1,2,3) in sb_dirty, we have
some flags instead:
MD_CHANGE_DEVS
Some device state has changed requiring superblock update
on all devices.
MD_CHANGE_CLEAN
The array has transitions from 'clean' to 'dirty' or back,
requiring a superblock update on active devices, but possibly
not on spares
MD_CHANGE_PENDING
A superblock update is underway.We wait for an update to complete by waiting for all flags to be clear. A
flag can be set at any time, even during an update, without risk that the
change will be lost.Stop exporting md_update_sb - isn't needed.
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
raid10d has toooo many nested block, so take the fix_read_error functionality
out into a separate function.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
11 Jul, 2006
1 commit
-
This is generally useful, but particularly helps see if it is the same sector
that always needs correcting, or different ones.[akpm@osdl.org: fix printk warnings]
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Jun, 2006
4 commits
-
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 -
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 -
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 -
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
02 May, 2006
2 commits
-
We need to hold a reference to rdevs while reading and writing to attempt to
correct read errors. This reference must be taken under an rcu lock.Signed-off-by: Neil Brown
Cc: "Paul E. McKenney"
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We should add to the counter for the rdev *after* checking if the rdev is
NULL!!!Signed-off-by: Neil Brown
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Apr, 2006
1 commit
-
this changes if() BUG(); constructs to BUG_ON() which is
cleaner and can better optimized awaySigned-off-by: Eric Sesterhenn
Signed-off-by: Adrian Bunk
04 Feb, 2006
1 commit
-
- version-1 superblock
+ The default_bitmap_offset is in sectors, not bytes.
+ the 'size' field in the superblock is in sectors, not KB
- raid0_run should return a negative number on error, not '1'
- raid10_read_balance should not return a valid 'disk' number if
->rdev turned out to be NULL
- kmem_cache_destroy doesn't like being passed a NULL.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
15 Jan, 2006
1 commit
-
Remove the "inline" keyword from a bunch of big functions in the kernel with
the goal of shrinking it by 30kb to 40kbSigned-off-by: Arjan van de Ven
Signed-off-by: Ingo Molnar
Acked-by: Jeff Garzik
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Jan, 2006
14 commits
-
Store this total in superblock (As appropriate), and make it available to
userspace via sysfs.Signed-off-by: Neil Brown
Acked-by: Greg KH
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Signed-off-by: Neil Brown
Acked-by: Greg KH
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 -
md sometimes call put_page on NULL pointers (treating it like kfree). This is
not safe, so define and use a 'safe_put_page' which checks for NULL.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The code to overwrite/reread for addressing read errors in raid1/raid10
currently assumes that the read will not alter the buffer which could be used
to write to the next device. This is not a safe assumption to make.So we split the loops into a overwrite loop and a separate re-read loop, so
that the writing is complete before reading is attempted.Cc: Paul Clements
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
md supports multiple different RAID level, each being implemented by a
'personality' (which is often in a separate module).These personalities have fairly artificial 'numbers'. The numbers
are use to:
1- provide an index into an array where the various personalities
are recorded
2- identify the module (via an alias) which implements are particular
personality.Neither of these uses really justify the existence of personality numbers.
The array can be replaced by a linked list which is searched (array lookup
only happens very rarely). Module identification can be done using an alias
based on level rather than 'personality' number.The current 'raid5' modules support two level (4 and 5) but only one
personality. This slight awkwardness (which was handled in the mapping from
level to personality) can be better handled by allowing raid5 to register 2
personalities.With this change in place, the core md module does not need to have an
exhaustive list of all possible personalities, so other personalities can be
added independently.This patch also moves the check for chunksize being non-zero into the ->run
routines for the personalities that need it, rather than having it in core-md.
This has a side effect of allowing 'faulty' and 'linear' not to have a
chunk-size set.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 -
Replace multiple kmalloc/memset pairs with kzalloc calls.
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Substitute:
page_cache_get -> get_page
page_cache_release -> put_page
PAGE_CACHE_SHIFT -> PAGE_SHIFT
PAGE_CACHE_SIZE -> PAGE_SIZE
PAGE_CACHE_MASK -> PAGE_MASK
__free_page -> put_pagebecause we aren't using the page cache, we are just using pages.
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add in correct read-error handling for resync and read-only situations.
When read-only, we don't over-write, so we need to mark the failed drive in
the r10_bio so we don't re-try it. During resync, we always read all blocks,
so if there is a read error, we simply over-write it with the good block that
we found (assuming we found one).Note that the recovery case still isn't handled in an interesting way. There
is nothing useful to do for the 2-copies case. If there are 3 or more copies,
then we could try reading from one of the non-missing copies, but this is a
bit complicated and very rarely would be used, so I'm leaving it for now.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Largely just a cross-port from raid1.
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Also keep count on the number of errors found.
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 -
raid10 needs to put up a barrier to new requests while it does resync or other
background recovery. The code for this is currently open-coded, slighty
obscure by its use of two waitqueues, and not documented.This patch gathers all the related code into 4 functions, and includes a
comment which (hopefully) explains what is happening.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Nov, 2005
1 commit
-
raid10 has two different layouts. One uses near-copies (so multiple
copies of a block are at the same or similar offsets of different
devices) and the other uses far-copies (so multiple copies of a block
are stored a greatly different offsets on different devices). The point
of far-copies is that it allows the first section (normally first half)
to be layed out in normal raid0 style, and thus provide raid0 sequential
read performance.Unfortunately, the read balancing in raid10 makes some poor decisions
for far-copies arrays and you don't get the desired performance. So
turn off that bad bit of read_balance for far-copies arrays.With this patch, read speed of an 'f2' array is comparable with a raid0
with the same number of devices, though write speed is ofcourse still
very slow.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Nov, 2005
2 commits
-
This has the advantage of removing the confusion caused by 'rdev_t' and
'mddev_t' both having 'in_sync' fields.Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Acked-by:
Signed-off-by: Suzanne Wood
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
01 Nov, 2005
1 commit
-
Instead of having ->read_sectors and ->write_sectors, combine the two
into ->sectors[2] and similar for the other fields. This saves a branch
several places in the io path, since we don't have to care for what the
actual io direction is. On my x86-64 box, that's 200 bytes less text in
just the core (not counting the various drivers).Signed-off-by: Jens Axboe
09 Oct, 2005
1 commit
-
- added typedef unsigned int __nocast gfp_t;
- replaced __nocast uses for gfp flags with gfp_t - it gives exactly
the same warnings as far as sparse is concerned, doesn't change
generated code (from gcc point of view we replaced unsigned int with
typedef) and documents what's going on far better.Signed-off-by: Al Viro
Signed-off-by: Linus Torvalds
10 Sep, 2005
1 commit
-
This shouldn't be a BUG. We should cope.
Signed-off-by: Neil Brown
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds