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2012-01-16Btrfs: allow for canceling restriperIlya Dryomov
Implement an ioctl for canceling restriper. Currently we wait until relocation of the current block group is finished, in future this can be done by triggering a commit. Balance item is deleted and no memory about the interrupted balance is kept. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: allow for pausing restriperIlya Dryomov
Implement an ioctl for pausing restriper. This pauses the relocation, but balance is still considered to be "in progress": balance item is not deleted, other volume operations cannot be started, etc. If paused in the middle of profile changing operation we will continue making allocations with the target profile. Add a hook to close_ctree() to pause restriper and free its data structures on unmount. (It's safe to unmount when restriper is in "paused" state, we will resume with the same parameters on the next mount) Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: add skip_balance mount optionIlya Dryomov
Since restriper kthread starts involuntarily on mount and can suck cpu and memory bandwidth add a mount option to forcefully skip it. The restriper in that case hangs around in paused state and can be resumed from userspace when it's convenient. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: recover balance on mountIlya Dryomov
On mount, if balance item is found, resume balance in a separate kernel thread. Try to be smart to continue roughly where previous balance (or convert) was interrupted. For chunk types that were being converted to some profile we turn on soft convert, in case of a simple balance we turn on usage filter and relocate only less-than-90%-full chunks of that type. These are just heuristics but they help quite a bit, and can be improved in future. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: save balance parameters to diskIlya Dryomov
Introduce a new btree objectid for storing balance item. The reason is to be able to resume restriper after a crash with the same parameters. Balance item has a very high objectid and goes into tree of tree roots. The key for the new item is as follows: [ BTRFS_BALANCE_OBJECTID ; BTRFS_BALANCE_ITEM_KEY ; 0 ] Older kernels simply ignore it so it's safe to mount with an older kernel and then go back to the newer one. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: soft profile changing mode (aka soft convert)Ilya Dryomov
When doing convert from one profile to another if soft mode is on restriper won't touch chunks that already have the profile we are converting to. This is useful if e.g. half of the FS was converted earlier. The soft mode switch is (like every other filter) per-type. This means that we can convert for example meta chunks the "hard" way while converting data chunks selectively with soft switch. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: implement online profile changingIlya Dryomov
Profile changing is done by launching a balance with BTRFS_BALANCE_CONVERT bits set and target fields of respective btrfs_balance_args structs initialized. Profile reducing code in this case will pick restriper's target profile if it's available instead of doing a blind reduce. If target profile is not yet available it goes back to a plain reduce. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: do not reduce profile in do_chunk_alloc()Ilya Dryomov
Every caller of do_chunk_alloc() feeds it the reduced allocation profile, so stop trying to reduce it one more time. Instead check the validity of the passed profile. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: virtual address space subset filterIlya Dryomov
Select chunks which have at least one byte located inside a given [vstart, vend) virtual address space range. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: devid subset filterIlya Dryomov
Select chunks which have at least one byte of at least one stripe located on a device with devid X in a given [pstart,pend) physical address range. This filter only works when devid filter is turned on. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: devid filterIlya Dryomov
Relocate chunks which have at least one stripe located on a device with devid X. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: usage filterIlya Dryomov
Select chunks that are less than X percent full. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: profiles filterIlya Dryomov
Select chunks based on a given profile mask. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: add basic infrastructure for selective balancingIlya Dryomov
This allows to have a separate set of filters for each chunk type (data,meta,sys). The code however is generic and switch on chunk type is only done once. This commit also adds a type filter: it allows to balance for example meta and system chunks w/o touching data ones. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: add basic restriper infrastructureIlya Dryomov
Add basic restriper infrastructure: extended balancing ioctl and all related ioctl data structures, add data structure for tracking restriper's state to fs_info, etc. The semantics of the old balancing ioctl are fully preserved. Explicitly disallow any volume operations when balance is in progress. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: make avail_*_alloc_bits fields dynamicIlya Dryomov
Currently when new chunks are created respective avail_alloc_bits field is updated to reflect profiles of all chunks present in the system. However when chunks are removed profile bits are never cleared. This patch clears profile bit of respective avail_alloc_bits field when the last chunk with that profile is removed. Restriper needs this to properly operate when "downgrading". Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: add BTRFS_AVAIL_ALLOC_BIT_SINGLE bitIlya Dryomov
Right now on-disk BTRFS_BLOCK_GROUP_* profile bits are used for avail_{data,metadata,system}_alloc_bits fields, which gather info about available allocation profiles in the FS. When chunk is created or read from disk, its profile is OR'ed with the corresponding avail_alloc_bits field. Since SINGLE is denoted by 0 in the on-disk format, currently there is no way to tell when such chunks become avaialble. Restriper needs that information, so add a separate bit for SINGLE profile. This bit is going to be in-memory only, it should never be written out to disk, so it's not a disk format change. However to avoid remappings in future, reserve corresponding on-disk bit. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: introduce masks for chunk type and profileIlya Dryomov
Chunk's type and profile are encoded in u64 flags field. Introduce masks to easily access them. Also fix the type of BTRFS_BLOCK_GROUP_* constants, it should be ULL. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2012-01-16Btrfs: get rid of *_alloc_profile fieldsIlya Dryomov
{data,metadata,system}_alloc_profile fields have been unused for a long time now. Get rid of them. Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2011-12-23Btrfs: call d_instantiate after all ops are setupAl Viro
This closes races where btrfs is calling d_instantiate too soon during inode creation. All of the callers of btrfs_add_nondir are updated to instantiate after the inode is fully setup in memory. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-23Btrfs: fix worker lock misuse in find_workerChris Mason
Dan Carpenter noticed that we were doing a double unlock on the worker lock, and sometimes picking a worker thread without the lock held. This fixes both errors. Signed-off-by: Chris Mason <chris.mason@oracle.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
2011-12-15Btrfs: unplug every once and a whileChris Mason
The btrfs io submission threads can build up massive plug lists. This keeps things more reasonable so we don't hand over huge dumps of IO at once. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-15Merge branch 'for-chris' of ↵Chris Mason
http://git.kernel.org/pub/scm/linux/kernel/git/josef/btrfs-work into integration Conflicts: fs/btrfs/inode.c Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-15Btrfs: deal with NULL srv_rsv in the delalloc inode reservation codeChris Mason
btrfs_update_inode is sometimes called with a null reservation. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-15Btrfs: only set cache_generation if we setup the block groupJosef Bacik
A user reported a problem booting into a new kernel with the old format inodes. He was panicing in cow_file_range while writing out the inode cache. This is because if the block group is not cached we'll just skip writing out the cache, however if it gets dirtied again in the same transaction and it finished caching we'd go ahead and write it out, but since we set cache_generation to the transid we think we've already truncated it and will just carry on, running into cow_file_range and blowing up. We need to make sure we only set cache_generation if we've done the truncate. The user tested this patch and verified that the panic no longer occured. Thanks, Reported-and-Tested-by: Klaus Bitto <klaus.bitto@gmail.com> Signed-off-by: Josef Bacik <josef@redhat.com>
2011-12-15Btrfs: don't panic if orphan item already existsJosef Bacik
I've been hitting this BUG_ON() in btrfs_orphan_add when running xfstest 269 in a loop. This is because we will add an orphan item, do the truncate, the truncate will fail for whatever reason (*cough*ENOSPC*cough*) and then we're left with an orphan item still in the fs. Then we come back later to do another truncate and it blows up because we already have an orphan item. This is ok so just fix the BUG_ON() to only BUG() if ret is not EEXIST. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2011-12-15Btrfs: fix leaked space in truncateJosef Bacik
We were occasionaly leaking space when running xfstest 269. This is because if we failed to start the transaction in the truncate loop we'd just goto out, but we need to break so that the inode is removed from the orphan list and the space is properly freed. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2011-12-15Btrfs: fix how we do delalloc reservations and how we free reservations on errorJosef Bacik
Running xfstests 269 with some tracing my scripts kept spitting out errors about releasing bytes that we didn't actually have reserved. This took me down a huge rabbit hole and it turns out the way we deal with reserved_extents is wrong, we need to only be setting it if the reservation succeeds, otherwise the free() method will come in and unreserve space that isn't actually reserved yet, which can lead to other warnings and such. The math was all working out right in the end, but it caused all sorts of other issues in addition to making my scripts yell and scream and generally make it impossible for me to track down the original issue I was looking for. The other problem is with our error handling in the reservation code. There are two cases that we need to deal with 1) We raced with free. In this case free won't free anything because csum_bytes is modified before we dro the lock in our reservation path, so free rightly doesn't release any space because the reservation code may be depending on that reservation. However if we fail, we need the reservation side to do the free at that point since that space is no longer in use. So as it stands the code was doing this fine and it worked out, except in case #2 2) We don't race with free. Nobody comes in and changes anything, and our reservation fails. In this case we didn't reserve anything anyway and we just need to clean up csum_bytes but not free anything. So we keep track of csum_bytes before we drop the lock and if it hasn't changed we know we can just decrement csum_bytes and carry on. Because of the case where we can race with free()'s since we have to drop our spin_lock to do the reservation, I'm going to serialize all reservations with the i_mutex. We already get this for free in the heavy use paths, truncate and file write all hold the i_mutex, just needed to add it to page_mkwrite and various ioctl/balance things. With this patch my space leak scripts no longer scream bloody murder. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2011-12-15Btrfs: deal with enospc from dirtying inodes properlyJosef Bacik
Now that we're properly keeping track of delayed inode space we've been getting a lot of warnings out of btrfs_dirty_inode() when running xfstest 83. This is because a bunch of people call mark_inode_dirty, which is void so we can't return ENOSPC. This needs to be fixed in a few areas 1) file_update_time - this updates the mtime and such when writing to a file, which will call mark_inode_dirty. So copy file_update_time into btrfs so we can call btrfs_dirty_inode directly and return an error if we get one appropriately. 2) fix symlinks to use btrfs_setattr for ->setattr. For some reason we weren't setting ->setattr for symlinks, even though we should have been. This catches one of the cases where we were getting errors in mark_inode_dirty. 3) Fix btrfs_setattr and btrfs_setsize to call btrfs_dirty_inode directly instead of mark_inode_dirty. This lets us return errors properly for truncate and chown/anything related to setattr. 4) Add a new btrfs_fs_dirty_inode which will just call btrfs_dirty_inode and print an error if we have one. The only remaining user we can't control for this is touch_atime(), but we don't really want to keep people from walking down the tree if we don't have space to save the atime update, so just complain but don't worry about it. With this patch xfstests 83 complains a handful of times instead of hundreds of times. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2011-12-15Btrfs: fix num_workers_starting bug and other bugs in async threadJosef Bacik
Al pointed out we have some random problems with the way we account for num_workers_starting in the async thread stuff. First of all we need to make sure to decrement num_workers_starting if we fail to start the worker, so make __btrfs_start_workers do this. Also fix __btrfs_start_workers so that it doesn't call btrfs_stop_workers(), there is no point in stopping everybody if we failed to create a worker. Also check_pending_worker_creates needs to call __btrfs_start_work in it's work function since it already increments num_workers_starting. People only start one worker at a time, so get rid of the num_workers argument everywhere, and make btrfs_queue_worker a void since it will always succeed. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
2011-12-15BTRFS: Establish i_ops before calling d_instantiateCasey Schaufler
The Smack LSM hook for security_d_instantiate checks the inode's i_op->getxattr value to determine if the containing filesystem supports extended attributes. The BTRFS filesystem sets the inode's i_op value only after it has instantiated the inode. This results in Smack incorrectly giving new BTRFS inodes attributes from the filesystem defaults on the assumption that values can't be stored on the filesystem. This patch moves the assignment of inode operation vectors ahead of the calls to d_instantiate, letting Smack know that the filesystem supports extended attributes. There should be no impact on the performance or behavior of BTRFS. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-15Btrfs: add a cond_resched() into the worker loopChris Mason
If we have a constant stream of end_io completions or crc work, we can hit softlockup messages from the async helper threads. This adds a cond_resched() into the loop to avoid them. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-15Btrfs: fix ctime update of on-disk inodeLi Zefan
To reproduce the bug: # touch /mnt/tmp # stat /mnt/tmp | grep Change Change: 2011-12-09 09:32:23.412105981 +0800 # chattr +i /mnt/tmp # stat /mnt/tmp | grep Change Change: 2011-12-09 09:32:43.198105295 +0800 # umount /mnt # mount /dev/loop1 /mnt # stat /mnt/tmp | grep Change Change: 2011-12-09 09:32:23.412105981 +0800 We should update ctime of in-memory inode before calling btrfs_update_inode(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-15btrfs: keep orphans for subvolume deletionArne Jansen
Since we have the free space caches, btrfs_orphan_cleanup also runs for the tree_root. Unfortunately this also cleans up the orphans used to mark subvol deletions in progress. Currently if a subvol deletion gets interrupted twice by umount/mount, the deletion will not be continued and the space permanently lost, though it would be possible to write a tool to recover those lost subvol deletions. This patch checks if the orphan belongs to a subvol (dead root) and skips the deletion. Signed-off-by: Arne Jansen <sensille@gmx.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-15Btrfs: fix inaccurate available space on raid0 profileMiao Xie
When we use raid0 as the data profile, df command may show us a very inaccurate value of the available space, which may be much less than the real one. It may make the users puzzled. Fix it by changing the calculation of the available space, and making it be more similar to a fake chunk allocation. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-15Btrfs: fix wrong disk space information of the filesMiao Xie
Btrfsck report errors after the 83th case of xfstests was run, The error number is 400, it means the used disk space of the file is wrong. The reason of this bug is that: The file truncation may fail when the space of the file system is not enough, and leave some file extents, whose offset are beyond the end of the files. When we want to expand those files, we will drop those file extents, and put in dummy file extents, and then we should update the i-node. But btrfs forgets to do it. This patch adds the forgotten i-node update. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-15Btrfs: fix wrong i_size when truncating a file to a larger sizeMiao Xie
Btrfsck report error 100 after the 83th case of xfstests was run, it means the i_size of the file is wrong. The reason of this bug is that: Btrfs increased i_size of the file at the beginning, but it failed to expand the file, and failed to update the i_size to the old size because there is no enough space in the file system, so we found a wrong i_size. This patch fixes this bug by updating the i_size just when we pass the file expanding and get enough space to update i-node. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-09Btrfs: fix btrfs_end_bio to deal with write errors to a single mirrorChris Mason
btrfs_end_bio checks the number of errors on a bio against the max number of errors allowed before sending any EIOs up to the higher levels. If we got enough copies of the bio done for a given raid level, it is supposed to clear the bio error flag and return success. We have pointers to the original bio sent down by the higher layers and pointers to any cloned bios we made for raid purposes. If the original bio happens to be the one that got an io error, but not the last one to finish, it might not have the BIO_UPTODATE bit set. Then, when the last bio does finish, we'll call bio_end_io on the original bio. It won't have the uptodate bit set and we'll end up sending EIO to the higher layers. We already had a check for this, it just was conditional on getting the IO error on the very last bio. Make the check unconditional so we eat the EIOs properly. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-08Btrfs: drop spin lock when memory alloc failsLiu Bo
Drop spin lock in convert_extent_bit() when memory alloc fails, otherwise, it will be a deadlock. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-08Btrfs: check if the to-be-added device is writableLi Zefan
If we call ioctl(BTRFS_IOC_ADD_DEV) directly, we'll succeed in adding a readonly device to a btrfs filesystem, and btrfs will write to that device, emitting kernel errors: [ 3109.833692] lost page write due to I/O error on loop2 [ 3109.833720] lost page write due to I/O error on loop2 ... Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-08Btrfs: try cluster but don't advance in search listAlexandre Oliva
When we find an existing cluster, we switch to its block group as the current block group, possibly skipping multiple blocks in the process. Furthermore, under heavy contention, multiple threads may fail to allocate from a cluster and then release just-created clusters just to proceed to create new ones in a different block group. This patch tries to allocate from an existing cluster regardless of its block group, and doesn't switch to that group, instead proceeding to try to allocate a cluster from the group it was iterating before the attempt. Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-07Btrfs: try to allocate from cluster even at LOOP_NO_EMPTY_SIZEAlexandre Oliva
If we reach LOOP_NO_EMPTY_SIZE, we won't even try to use a cluster that others might have set up. Odds are that there won't be one, but if someone else succeeded in setting it up, we might as well use it, even if we don't try to set up a cluster again. Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-12-01Btrfs: fix meta data raid-repair merge problemJan Schmidt
Commit 4a54c8c16 introduced raid-repair, killing the individual readpage_io_failed_hook entries from inode.c and disk-io.c. Commit 4bb31e92 introduced new readahead code, adding a readpage_io_failed_hook to disk-io.c. The raid-repair commit had logic to disable raid-repair, if readpage_io_failed_hook is set. Thus, the readahead commit effectively disabled raid-repair for meta data. This commit changes the logic to always attempt raid-repair when needed and call the readpage_io_failed_hook in case raid-repair fails. This is much more straight forward and should have been like that from the beginning. Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net> Reported-by: Stefan Behrens <sbehrens@giantdisaster.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-11-30Btrfs: skip allocation attempt from empty clusterAlexandre Oliva
If we don't have a cluster, don't bother trying to allocate from it, jumping right away to the attempt to allocate a new cluster. Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-11-30Btrfs: skip block groups without enough space for a clusterAlexandre Oliva
We test whether a block group has enough free space to hold the requested block, but when we're doing clustered allocation, we can save some cycles by testing whether it has enough room for the cluster upfront, otherwise we end up attempting to set up a cluster and failing. Only in the NO_EMPTY_SIZE loop do we attempt an unclustered allocation, and by then we'll have zeroed the cluster size, so this patch won't stop us from using the block group as a last resort. Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-11-30Btrfs: start search for new cluster at the beginningAlexandre Oliva
Instead of starting at zero (offset is always zero), request a cluster starting at search_start, that denotes the beginning of the current block group. Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-11-30Btrfs: reset cluster's max_size when creating bitmapAlexandre Oliva
The field that indicates the size of the largest contiguous chunk of free space in the cluster is not initialized when setting up bitmaps, it's only increased when we find a larger contiguous chunk. We end up retaining a larger value than appropriate for highly-fragmented clusters, which may cause pointless searches for large contiguous groups, and even cause clusters that do not meet the density requirements to be set up. Signed-off-by: Alexandre Oliva <oliva@lsd.ic.unicamp.br> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-11-30Btrfs: initialize new bitmaps' listAlexandre Oliva
We're failing to create clusters with bitmaps because setup_cluster_no_bitmap checks that the list is empty before inserting the bitmap entry in the list for setup_cluster_bitmap, but the list field is only initialized when it is restored from the on-disk free space cache, or when it is written out to disk. Besides a potential race condition due to the multiple use of the list field, filesystem performance severely degrades over time: as we use up all non-bitmap free extents, the try-to-set-up-cluster dance is done at every metadata block allocation. For every block group, we fail to set up a cluster, and after failing on them all up to twice, we fall back to the much slower unclustered allocation. To make matters worse, before the unclustered allocation, we try to create new block groups until we reach the 1% threshold, which introduces additional bitmaps and thus block groups that we'll iterate over at each metadata block request.
2011-11-30Btrfs: fix oops when calling statfs on readonly deviceLi Zefan
To reproduce this bug: # dd if=/dev/zero of=img bs=1M count=256 # mkfs.btrfs img # losetup -r /dev/loop1 img # mount /dev/loop1 /mnt OOPS!! It triggered BUG_ON(!nr_devices) in btrfs_calc_avail_data_space(). To fix this, instead of checking write-only devices, we check all open deivces: # df -h /dev/loop1 Filesystem Size Used Avail Use% Mounted on /dev/loop1 250M 28K 238M 1% /mnt Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
2011-11-30Btrfs: Don't error on resizing FS to same sizeMike Fleetwood
It seems overly harsh to fail a resize of a btrfs file system to the same size when a shrink or grow would succeed. User app GParted trips over this error. Allow it by bypassing the shrink or grow operation. Signed-off-by: Mike Fleetwood <mike.fleetwood@googlemail.com>