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path: root/drivers/md/md.c
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2005-10-26[PATCH] md: make sure mdthreads will always respond to kthread_stopNeilBrown
There are still a couple of cases where md threads (the resync/recovery thread) is not interruptible since the change to use kthreads. All places there it tests "signal_pending", it should also test kthread_should_stop, as with this 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>
2005-10-19[PATCH] Three one-liners in md.cNeilBrown
The main problem fixes is that in certain situations stopping md arrays may take longer than you expect, or may require multiple attempts. This would only happen when resync/recovery is happening. This patch fixes three vaguely related bugs. 1/ The recent change to use kthreads got the setting of the process name wrong. This fixes it. 2/ The recent change to use kthreads lost the ability for md threads to be signalled with SIG_KILL. This restores that. 3/ There is a long standing bug in that if: - An array needs recovery (onto a hot-spare) and - The recovery is being blocked because some other array being recovered shares a physical device and - The recovery thread is killed with SIG_KILL Then the recovery will appear to have completed with no IO being done, which can cause data corruption. This patch makes sure that incomplete recovery will be treated as incomplete. Note that any kernel affected by bug 2 will not suffer the problem of bug 3, as the signal can never be delivered. Thus the current 2.6.14-rc kernels are not susceptible to data corruption. Note also that if arrays are shutdown (with "mdadm -S" or "raidstop") then the problem doesn't occur. It only happens if a SIGKILL is independently delivered as done by 'init' when shutting down. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-10[PATCH] merge some from Rusty's trivial patchesAdrian Bunk
This patch contains the most trivial from Rusty's trivial patches: - spelling fixes - remove duplicate includes Signed-off-by: Adrian Bunk <bunk@stusta.de> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: really get sb_size setting right in all casesNeilBrown
There was another case where sb_size wasn't being set, so instead do the sensible thing and set if when filling in the content of a superblock. That ensures that whenever we write a superblock, the sb_size MUST be set. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: make sure the new 'sb_size' is set properly device added without ↵NeilBrown
pre-existing superblock. There are two ways to add devices to an md/raid array. It can have superblock written to it, and then given to the md driver, which will read the superblock (the new way) or md can be told (through SET_ARRAY_INFO) the shape of the array, and the told about individual drives, and md will create the required superblock (the old way). The newly introduced sb_size was only set for drives being added the new way, not the old ways. Oops :-( Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: report spare drives in /proc/mdstatNeilBrown
Just like failed drives have (F), so spare drives now have (S). Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: add information about superblock version to /proc/mdstatNeilBrown
Leave it unchanged if the original (0.90) is used, incase it might be a compatability problem. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: use queue_hardsect_size instead of block_size for md superblock ↵NeilBrown
size calc. Doh. I want the physical hard-sector-size, not the current block size... Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: choose better default offset for bitmap.NeilBrown
On reflection, a better default location for hot-adding bitmaps with version-1 superblocks is immediately after the superblock. There might not be much room there, but there is usually atleast 3k, and that is a good start. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: use kthread infrastructure in mdNeilBrown
Switch MD to use the kthread infrastructure, to simplify the code and get rid of tasklist_lock abuse in md_unregister_thread. Also don't flush signals in md_thread, as the called thread will always do that. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: write-intent bitmap support for raid6NeilBrown
This is a direct port of the raid5 patch. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: add write-intent-bitmap support to raid5NeilBrown
Most awkward part of this is delaying write requests until bitmap updates have been flushed. To achieve this, we have a sequence number (seq_flush) which is incremented each time the raid5 is unplugged. If the raid thread notices that this has changed, it flushes bitmap changes, and assigned the value of seq_flush to seq_write. When a write request arrives, it is given the number from seq_write, and that write request may not complete until seq_flush is larger than the saved seq number. We have a new queue for storing stripes which are waiting for a bitmap flush and an extra flag for stripes to record if the write was 'degraded' and so should not clear the a bit in the bitmap. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: limit size of sb read/written to appropriate amountNeilBrown
version-1 superblocks are not (normally) 4K long, and can be of variable size. Writing the full 4K can cause corruption (but only in non-default configurations). With this patch the super-block-flavour can choose a size to read, and set a size to write based on what it finds. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: allow md to load a superblock with feature-bit '1' setNeilBrown
As this is used to flag an internal bitmap. Also, introduce symbolic names for feature bits. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: allow hot-adding devices to arrays with non-persistant superblocks.NeilBrown
It is possibly (and occasionally useful) to have a raid1 without persistent superblocks. The code in add_new_disk for adding a device to such an array always tries to read a superblock. This will obviously fail. So do the appropriate test and call md_import_device with appropriate args. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: support write-mostly device in raid1NeilBrown
This allows a device in a raid1 to be marked as "write mostly". Read requests will only be sent if there is no other option. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: all hot-add and hot-remove of md intent logging bitmapsNeilBrown
Both file-bitmaps and superblock bitmaps are supported. If you add a bitmap file on the array device, you lose. This introduces a 'default_bitmap_offset' field in mddev, as the ioctl used for adding a superblock bitmap doesn't have room for giving an offset. Later, this value will be setable via sysfs. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] md: don't allow new md/bitmap file to be set if one already existsNeilBrown
... otherwise we loose a reference and can never free the file. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-09-09[PATCH] trivial __user annotations (md)viro@ZenIV.linux.org.uk
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-26[PATCH] md: clear the 'recovery' flags when starting an md array.NeilBrown
It's possible for this to still have flags in it and a previous instance has been stopped, and that confused the new array using the same mddev. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-26[PATCH] md: create a MODULE_ALIAS for md corresponding to its block major ↵NeilBrown
number. I just discovered this is needed for module auto-loading. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-23[PATCH] md: make sure resync gets started when array starts.NeilBrown
We weren't actually waking up the md thread after setting MD_RECOVERY_NEEDED when assembling an array, so it is possible to lose a race and not actually start resync. So add a call to md_wakeup_thread, and while we are at it, remove all the "if (mddev->thread)" guards as md_wake_thread does its own checking. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-18[PATCH] md: make sure mddev->bitmap_offset gets cleared between array ↵NeilBrown
instantiations. ... otherwise we might try to load a bitmap from an array which hasn't one. The bug is that if you create an array with an internal bitmap, shut it down, and then create an array with the same md device, the md drive will assume it should have a bitmap too. As the array can be created with a different md device, it is mostly an inconvenience. I'm pretty sure there is no risk of data corruption. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-04[PATCH] md: make sure md bitmap updates are flushed when array is stopped.NeilBrown
The recent change to never ignore the bitmap, revealed that the bitmap isn't begin flushed properly when an array is stopped. We call bitmap_daemon_work three times as there is a three-stage pipeline for flushing updates to the bitmap file. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-04[PATCH] md: make 'md' and alias for 'md-mod'NeilBrown
Until the bitmap code was added, modprobe md would load the md module. But now the md module is called 'md-mod', so we really need an alias for backwards comparability. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-08-04[PATCH] md: remove a stray debugging printk.NeilBrown
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-07-27[PATCH] clean up inline static vs static inlineJesper Juhl
`gcc -W' likes to complain if the static keyword is not at the beginning of the declaration. This patch fixes all remaining occurrences of "inline static" up with "static inline" in the entire kernel tree (140 occurrences in 47 files). While making this change I came across a few lines with trailing whitespace that I also fixed up, I have also added or removed a blank line or two here and there, but there are no functional changes in the patch. Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-28[PATCH] md: bio leak fixNeil Brown
insert a missing bio_put when writting the md superblock. Without this we have a steady growth in the "bio" slab. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-25[PATCH] Cleanup patch for process freezingChristoph Lameter
1. Establish a simple API for process freezing defined in linux/include/sched.h: frozen(process) Check for frozen process freezing(process) Check if a process is being frozen freeze(process) Tell a process to freeze (go to refrigerator) thaw_process(process) Restart process frozen_process(process) Process is frozen now 2. Remove all references to PF_FREEZE and PF_FROZEN from all kernel sources except sched.h 3. Fix numerous locations where try_to_freeze is manually done by a driver 4. Remove the argument that is no longer necessary from two function calls. 5. Some whitespace cleanup 6. Clear potential race in refrigerator (provides an open window of PF_FREEZE cleared before setting PF_FROZEN, recalc_sigpending does not check PF_FROZEN). This patch does not address the problem of freeze_processes() violating the rule that a task may only modify its own flags by setting PF_FREEZE. This is not clean in an SMP environment. freeze(process) is therefore not SMP safe! Signed-off-by: Christoph Lameter <christoph@lameter.com> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: remove unneeded NULL checks before kfreeJesper Juhl
This patch removes some unneeded checks of pointers being NULL before calling kfree() on them. kfree() handles NULL pointers just fine, checking first is pointless. Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] Two small fixes for md verion-1 superblocks.NeilBrown
1/ Must typecast int to (sector_t) before inverting or we might not invert enough bits. 2/ When "bitmap_offset" was added to mdp_superblock_1, we didn't increase the count of words-used (96 to 100). Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: allow md to update multiple superblocks in parallel.NeilBrown
currently, md updates all superblocks (one on each device) in series. It waits for one write to complete before starting the next. This isn't a big problem as superblock updates don't happen that often. However it is neater to do it in parallel, and if the drives in the array have gone to "sleep" after a period of idleness, then waking them is parallel is faster (and someone else should be worrying about power drain). Futher, we will need parallel superblock updates for a future patch which keeps the intent-logging bitmap near the superblock. Also remove the silly code that retired superblock updates 100 times. This simply never made sense. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: allow md intent bitmap to be stored near the superblock.NeilBrown
This provides an alternate to storing the bitmap in a separate file. The bitmap can be stored at a given offset from the superblock. Obviously the creator of the array must make sure this doesn't intersect with data.... After is good for version-0.90 superblocks. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: fix deadlock due to md thread processing delayed requests.NeilBrown
Before completing a 'write' the md superblock might need to be updated. This is best done by the md_thread. The current code schedules this up and queues the write request for later handling by the md_thread. However some personalities (Raid5/raid6) will deadlock if the md_thread tries to submit requests to its own array. So this patch changes things so the processes submitting the request waits for the superblock to be written and then submits the request itself. This fixes a recently-created deadlock in raid5/raid6 Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: optimise reconstruction when re-adding a recently failed drive.NeilBrown
When an array is degraded, bit in the intent-bitmap are never cleared. So if a recently failed drive is re-added, we only need to reconstruct the block that are still reflected in the bitmap. This patch adds support for this re-adding. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: call bitmap_daemon_work regularlyNeilBrown
bitmap_daemon_work clears bits in the bitmap for blocks that haven't been written to for a while. It needs to be called regularly to make sure the bitmap doesn't endup full of ones .... but it wasn't. So call it from the increasingly-inaptly-named md_check_recovery Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: a couple of tidyups relating to the bitmap file.NeilBrown
1/ When init from disk, it is a BUG if there is nowhere to init from, 2/ use seq_path to print path in /proc/mdstat Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: optimised resync using Bitmap based intent loggingNeilBrown
With this patch, the intent to write to some block in the array can be logged to a bitmap file. Each bit represents some number of sectors and is set before any update happens, and only cleared when all writes relating to all sectors are complete. After an unclean shutdown, information in this bitmap can be used to optimise resync - only sectors which could be out-of-sync need to be updated. Also if a drive is removed and then added back into an array, the recovery can make use of the bitmap to optimise reconstruction. This is not implemented in this patch. Currently the bitmap is stored in a file which must (obviously) be stored on a separate device. The patch only provided infrastructure. It does not update any personalities to bitmap intent logging. Md arrays can still be used with no bitmap file. This patch has minimal impact on such arrays. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: improve the interface to sync_requestNeilBrown
1/ change the return value (which is number-of-sectors synced) from 'int' to 'sector_t'. The number of sectors is usually easily small enough to fit in an int, but if resync needs to abort, it may want to return the total number of remaining sectors, which could be large. Also errors cannot be returned as negative numbers now, so use 0 instead 2/ Add a 'skipped' return parameter to allow the array to report that it skipped the sectors. This allows md to take this into account in the speed calculations. Currently there is no important skipping, but the bitmap-based-resync that is coming will use this. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: improve locking on 'safemode' and move superblock writesNeilBrown
When md marks the superblock dirty before a write, it calls generic_make_request (to write the superblock) from within generic_make_request (to write the first dirty block), which could cause problems later. With this patch, the superblock write is always done by the helper thread, and write request are delayed until that write completes. Also, the locking around marking the array dirty and writing the superblock is improved to avoid possible races. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: merge md_enter_safemode into md_check_recoveryNeilBrown
md_enter_safemode checks if it is time to mark the md superblock as 'clean'. i.e. if all writes have completed and a suitable delay has passed. This is currently called from md_handle_safemode which in-turn is called (almost) every time md_check_recovery is called, and from the end of md_do_sync which causes the mddev->thread to run, which will always call md_check_recovery as well. So it doesn't need to be a separate function and fits quite well into md_check_recovery. The "almost" is because multipathd calls md_check_recovery but not md_handle_safemode. This is OK because the code from md_enter_safemode is a no-op if mddev->safemode == 0, which it always is for a multipathd (providing we don't allow it to be set to 2 on a signal...) Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-06-21[PATCH] md: make sure recovery happens when add_new_disk is used for hot_addNeilBrown
Currently if add_new_disk is used to hot-add a drive to a degraded array, recovery doesn't start ... because we didn't tell it to. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-05-05[PATCH] make some things staticAdrian Bunk
This patch makes some needlessly global identifiers static. Signed-off-by: Adrian Bunk <bunk@stusta.de> Acked-by: Arjan van de Ven <arjanv@infradead.org> Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16[PATCH] md: remove a number of misleading calls to MD_BUGNeilBrown
The conditions that cause these calls to MD_BUG are not kernel bugs, just oddities in what userspace is asking for. Also convert analyze_sbs to return void, and the value it returned was always 0. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16[PATCH] md: close a small race in md thread deregistrationNeilBrown
There is a tiny race when de-registering an MD thread, in that the thread could disappear before it is set a SIGKILL, causing send_sig to have problems. This is most easily closed by holding tasklist_lock between enabling the thread to exit (setting ->run to NULL) and telling it to exit. (akpm: ick. Needs to use kthread API and stop using signals) Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16[PATCH] Avoid deadlock in sync_page_io by using GFP_NOIONeil Brown
..as sync_page_io can be called on the write-out path. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!