Rename sibling_count to ref_count and introduce get and put functions.
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>
Add a workqueue so that I/O can be queued up to be flushed from a separate
thread (e.g. if local interrupts are disabled).
A new per-snapshot spinlock pe_lock is introduced to protect queued_bios.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch rearranges the pending_complete() code so that the functional
changes in subsequent patches are clearer.
By consolidating the error and the non-error paths, we can move
error_snapshot_bios() and __flush_bios() in line.
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Mark McLoughlin <markmc@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch rearranges the snapshot_map code so that the functional changes in
subsequent patches are clearer.
The only functional change is to replace the existing read lock with a write
lock which the next patch needs.
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>
When suspending a device-mapper device, dm_suspend() sleeps until all
necessary I/O is completed. This state is triggered by a callback from
persistent_commit(). But some I/O can still be issued *after* the callback
(to prepare the next metadata area for use if the current one is full). This
patch delays the callback until after that I/O is complete.
Signed-off-by: Mark McLoughlin <markmc@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>
read_exception() and write_exception() only return an error if supplied with
an out-of-range index. If this ever happens it's the result of a bug in the
calling code so we handle this with an assertion and remove the error handling
in the callers.
Signed-off-by: Mark McLoughlin <markmc@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>
Fix the error handling when store.read_metadata is called: the error should be
returned immediately.
Signed-off-by: Mark McLoughlin <markmc@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>
The chunk size of snapshots cannot be changed so it is redundant to require it
as a parameter when activating an existing snapshot. Allow a value of zero in
this case and ignore it. For a new snapshot, use a default value if zero is
specified.
Signed-off-by: Mark McLoughlin <markmc@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>
While reading the code I found a bug in the error path in alloc_dev in dm.c
When blk_alloc_queue fails there is no call to free_minor.
This patch fixes the problem.
Signed-off-by: Ishai Rabinovitz <ishai@mellanox.co.il>
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>
The new ioctl code passes the wrong file pointer to the underlying device.
No file pointer is available so make a temporary fake one.
ioctl_by_bdev() does set_fs(KERNEL_DS) so it's for ioctls originating
within the kernel and unsuitable here. We are processing ioctls that
originated in userspace and mapping them to different devices. Fixing the
existing callers that pass a NULL file struct and consolidating the
fake_file users are separate matters to solve in later patches.
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>
Export blkdev_driver_ioctl for device-mapper.
If we get as far as the device-mapper ioctl handler, we know the ioctl is not
a standard block layer BLK* one, so we don't need to check for them a second
time and can call blkdev_driver_ioctl() directly.
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>
When an ioctl is performed on a multipath device simply pass it on to the
underlying block device through current_path. If current path is not yet
selected, select it.
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>
When an ioctl is performed on a device with a linear target, simply pass it on
to the underlying block device.
Note that the ioctl will pass through the filtering in blkdev_ioctl() twice.
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>
Extend the core device-mapper infrastructure to accept arbitrary ioctls on a
mapped device provided that it has exactly one target and it is capable of
supporting ioctls.
[We can't use unlocked_ioctl because we need 'inode': 'file' might be NULL.
Is it worth changing this?]
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Arnd Bergmann <arnd@arndb.de> wrote:
> Am Wednesday 21 June 2006 21:31 schrieb Alasdair G Kergon:
> > static struct block_device_operations dm_blk_dops = {
> > .open = dm_blk_open,
> > .release = dm_blk_close,
> > +.ioctl = dm_blk_ioctl,
> > .getgeo = dm_blk_getgeo,
> > .owner = THIS_MODULE
>
> I guess this also needs a ->compat_ioctl method, otherwise it won't
> work for ioctl numbers that have a compat_ioctl implementation in the
> low-level device driver.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Make it possible to disable the block layer. Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.
This patch does the following:
(*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
support.
(*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
an item that uses the block layer. This includes:
(*) Block I/O tracing.
(*) Disk partition code.
(*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.
(*) The SCSI layer. As far as I can tell, even SCSI chardevs use the
block layer to do scheduling. Some drivers that use SCSI facilities -
such as USB storage - end up disabled indirectly from this.
(*) Various block-based device drivers, such as IDE and the old CDROM
drivers.
(*) MTD blockdev handling and FTL.
(*) JFFS - which uses set_bdev_super(), something it could avoid doing by
taking a leaf out of JFFS2's book.
(*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
linux/elevator.h contingent on CONFIG_BLOCK being set. sector_div() is,
however, still used in places, and so is still available.
(*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
parts of linux/fs.h.
(*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.
(*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.
(*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
is not enabled.
(*) fs/no-block.c is created to hold out-of-line stubs and things that are
required when CONFIG_BLOCK is not set:
(*) Default blockdev file operations (to give error ENODEV on opening).
(*) Makes some /proc changes:
(*) /proc/devices does not list any blockdevs.
(*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.
(*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.
(*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
given command other than Q_SYNC or if a special device is specified.
(*) In init/do_mounts.c, no reference is made to the blockdev routines if
CONFIG_BLOCK is not defined. This does not prohibit NFS roots or JFFS2.
(*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
error ENOSYS by way of cond_syscall if so).
(*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
CONFIG_BLOCK is not set, since they can't then happen.
Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Right now ->flags is a bit of a mess: some are request types, and
others are just modifiers. Clean this up by splitting it into
->cmd_type and ->cmd_flags. This allows introduction of generic
Linux block message types, useful for sending generic Linux commands
to block devices.
Signed-off-by: Jens Axboe <axboe@suse.de>
Just some minor comment nits.
- little-endian is better than low-endian
- and since it is called essiv everywere it should also be essiv
in the comments (and not ess_iv)
Signed-off-by: Rik Snel <rsnel@cube.dyndns.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patch converts dm-crypt to use the new block cipher type where
applicable. It also changes simple cipher operations to use the new
encrypt_one/decrypt_one interface.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
We need to be careful when referencing mirrors[i].rdev. It can disappear
under us at various times.
So:
fix a couple of problem places.
comment a couple of non-problem places
move an 'atomic_add' which deferences rdev down a little
way to some where where it is sure to not be NULL.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A recent patch broke the ability to do a user-request check of a raid1.
This patch fixes the breakage and also moves a comment that was dislocated
by the same patch.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If we
- shut down a clean array,
- restart with one (or more) drive(s) missing
- make some changes
- pause, so that they array gets marked 'clean',
the event count on the superblock of included drives
will be the same as that of the removed drives.
So adding the removed drive back in will cause it
to be included with no resync.
To avoid this, we only update the eventcount backwards when the array
is not degraded. In this case there can (should) be no non-connected
drives that we can get confused with, and this is the particular case
where updating-backwards is valuable.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
On an nForce4-equipped machine with two SATA disk in raid1 setup using dmraid,
we experienced frequent deadlock of the system under high i/o load. 'cat
/dev/zero > ~/zero' was the most reliable way to reproduce them: Randomly
after a few GB, 'cp' would be left in 'D' state along with kjournald and
kmirrord. The functions cp and kjournald were blocked in did vary, but
kmirrord's wchan always pointed to 'mempool_alloc()'. We've seen this pattern
on 2.6.15 and 2.6.17 kernels. http://lkml.org/lkml/2005/4/20/142 indicates
that this problem has been around even before.
So much for the facts, here's my interpretation: mempool_alloc() first tries
to atomically allocate the requested memory, or falls back to hand out
preallocated chunks from the mempool. If both fail, it puts the calling
process (kmirrord in this case) on a private waitqueue until somebody refills
the pool. Where the only 'somebody' is kmirrord itself, so we have a
deadlock.
I worked around this problem by falling back to a (blocking) kmalloc when
before kmirrord would have ended up on the waitqueue. This defeats part of
the benefits of using the mempool, but at least keeps the system running. And
it could be done with a two-line change. Note that mempool_alloc() clears the
GFP_NOIO flag internally, and only uses it to decide whether to wait or return
an error if immediate allocation fails, so the attached patch doesn't change
behaviour in the non-deadlocking case. Path is against current git
(2.6.18-rc4), but should apply to earlier versions as well. I've tested on
2.6.15, where this patch makes the difference between random lockup and a
stable system.
Signed-off-by: Daniel Kobras <kobras@linux.de>
Acked-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>
Alasdair G Kergon
Mark McLoughlin
Milan Broz
Ishai Rabinovitz
David Howells
Jens Axboe
Rik Snel
Herbert Xu
NeilBrown
Daniel Kobras
Michal Miroslaw