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* [PATCH] md: Remove attempt to use dynamic names in sysfs for component ↵NeilBrown2005-11-09
| | | | | | | | | | | | | | | | | | | | devices on an MD array. With version-0.90 superblock, component devices on an md device to not have any stable name related to the array -(version-1 assigns a fixed index when a device is added to an array, and this remains despit any hot-swap). The intial code for making these devices appear in sysfs used dynamic names, which would change whenever a hot-spare was swapped for a failed or missing device. This turns out not to be practical in sysfs for a number of reasons. This patch changes then naming of component devices to be based on the result of 'bdevname'. This is stable and should be unique. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: support BIO_RW_BARRIER for md/raid1NeilBrown2005-11-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can only accept BARRIER requests if all slaves handle barriers, and that can, of course, change with time.... So we keep track of whether the whole array seems safe for barriers, and also whether each individual rdev handles barriers. We initially assumes barriers are OK. When writing the superblock we try a barrier, and if that fails, we flag things for no-barriers. This will usually clear the flags fairly quickly. If writing the superblock finds that BIO_RW_BARRIER is -ENOTSUPP, we need to resubmit, so introduce function "md_super_wait" which waits for requests to finish, and retries ENOTSUPP requests without the barrier flag. When writing the real raid1, write requests which were BIO_RW_BARRIER but which aresn't supported need to be retried. So raid1d is enhanced to do this, and when any bio write completes (i.e. no retry needed) we remove it from the r1bio, so that devices needing retry are easy to find. We should hardly ever get -ENOTSUPP errors when writing data to the raid. It should only happen if: 1/ the device used to support BARRIER, but now doesn't. Few devices change like this, though raid1 can! or 2/ the array has no persistent superblock, so there was no opportunity to pre-test for barriers when writing the superblock. Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: make md on-disk bitmaps not host-endianNeilBrown2005-11-09
| | | | | | | | | | | Current bitmaps use set_bit et.al and so are host-endian, which means not-portable. Oops. Define a new version number (4) for which bitmaps are little-endian. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: convert 'faulty' and 'in_sync' fields to bits in 'flags' fieldNeilBrown2005-11-09
| | | | | | | | | 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 <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: improvements to raid5 handling of read errorsNeilBrown2005-11-09
| | | | | | | | | | | | | Two refinements to the 'attempt-overwrite-on-read-error' mechanism. 1/ If the array is read-only, don't attempt an over-write. 2/ If there are more than max_nr_stripes read errors on a device with no success, fail the drive. This will make sure a dead drive will be eventually kicked even when we aren't trying to rewrite (which would normally kick a dead drive more quickly. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: change raid5 sysfs attribute to not create a new directoryNeilBrown2005-11-09
| | | | | | | | | | | | | | | There isn't really a need for raid5 attributes to be an a subdirectory, so this patch moves them from /sys/block/mdX/md/raid5/attribute to /sys/block/mdX/md/attribute This suggests that all md personalities should co-operate about namespace usage, but that shouldn't be a 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>
* [PATCH] md: minor MD fixesNeilBrown2005-11-09
| | | | | | | | | | | | | 1/ Use reduce stack usage, because 'gcc' apparently doesn't overlay different variables that are in separate scopes... 2/ Use test_bit instead of ( .. & 1<< ..) which in this case is buggy. Thanks to Andrew Morton Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: fix ref-counting problems with kobjects in mdNeilBrown2005-11-09
| | | | | | | | | Thanks Greg. Cc: Greg KH <greg@kroah.com> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: teach raid5 the difference between 'check' and 'repair'.NeilBrown2005-11-09
| | | | | | | | | | | With this, raid5 can be asked to check parity without repairing it. It also keeps a count of the number of incorrect parity blocks found (mismatches) and reports them through sysfs. Signed-off-by: Neil Brown <neilb@suse.de> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: allow a manual resync with mdNeilBrown2005-11-09
| | | | | | | | | | | | | | | | | | You can trigger a 'check' with echo check > /sys/block/mdX/md/scan_mode or a check-and-repair errors with echo repair > /sys/block/mdX/md/scan_mode and read the current state from the same file. Note: personalities need to know the different between 'check' and 'repair', but don't yet. Until they do, 'check' will be the same as 'repair' and will just do a normal resync pass. Signed-off-by: Neil Brown <neilb@suse.de> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: extend md sysfs support to component devices.NeilBrown2005-11-09
| | | | | | | | | | | | | | | | | Each device in an md array how has a corresponding /sys/block/mdX/md/devNN/ directory which can contain attributes. Currently there is only 'state' which summarises the state, nd 'super' which has a copy of the superblock, and 'block' which is a symlink to the block device. Also, /sys/block/mdX/md/rdNN represents slot 'NN' in the array, and is a symlink to the relevant 'devNN'. Obviously spare devices do not have a slot in the array, and so don't have such a symlink. Signed-off-by: Neil Brown <neilb@suse.de> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: initial sysfs support for mdNeilBrown2005-11-09
| | | | | | | | | | | Start using kobjects in mddevs, and provide a couple of simple attributes (level and disks). Attributes live in /sys/block/mdX/md/attr-name Signed-off-by: Neil Brown <neilb@suse.de> Cc: Greg KH <greg@kroah.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [BLOCK] Unify the seperate read/write io stat fields into arraysJens Axboe2005-11-01
| | | | | | | | | | 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 <axboe@suse.de>
* [PATCH] md: make sure mdthreads will always respond to kthread_stopNeilBrown2005-10-26
| | | | | | | | | | | 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>
* [PATCH] Three one-liners in md.cNeilBrown2005-10-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] merge some from Rusty's trivial patchesAdrian Bunk2005-09-10
| | | | | | | | | | | 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>
* [PATCH] md: really get sb_size setting right in all casesNeilBrown2005-09-09
| | | | | | | | | | 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>
* [PATCH] md: make sure the new 'sb_size' is set properly device added without ↵NeilBrown2005-09-09
| | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] md: report spare drives in /proc/mdstatNeilBrown2005-09-09
| | | | | | | | 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>
* [PATCH] md: add information about superblock version to /proc/mdstatNeilBrown2005-09-09
| | | | | | | | | 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>
* [PATCH] md: use queue_hardsect_size instead of block_size for md superblock ↵NeilBrown2005-09-09
| | | | | | | | | | 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>
* [PATCH] md: choose better default offset for bitmap.NeilBrown2005-09-09
| | | | | | | | | | 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>
* [PATCH] md: use kthread infrastructure in mdNeilBrown2005-09-09
| | | | | | | | | | | | | 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>
* [PATCH] md: write-intent bitmap support for raid6NeilBrown2005-09-09
| | | | | | | | 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>
* [PATCH] md: add write-intent-bitmap support to raid5NeilBrown2005-09-09
| | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] md: limit size of sb read/written to appropriate amountNeilBrown2005-09-09
| | | | | | | | | | | | | 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>
* [PATCH] md: allow md to load a superblock with feature-bit '1' setNeilBrown2005-09-09
| | | | | | | | | | 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>
* [PATCH] md: allow hot-adding devices to arrays with non-persistant superblocks.NeilBrown2005-09-09
| | | | | | | | | | | | | | | 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>
* [PATCH] md: support write-mostly device in raid1NeilBrown2005-09-09
| | | | | | | | | 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>
* [PATCH] md: all hot-add and hot-remove of md intent logging bitmapsNeilBrown2005-09-09
| | | | | | | | | | | | | | 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>
* [PATCH] md: don't allow new md/bitmap file to be set if one already existsNeilBrown2005-09-09
| | | | | | | | ... 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>
* [PATCH] trivial __user annotations (md)viro@ZenIV.linux.org.uk2005-09-09
| | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
* [PATCH] md: clear the 'recovery' flags when starting an md array.NeilBrown2005-08-26
| | | | | | | | | 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>
* [PATCH] md: create a MODULE_ALIAS for md corresponding to its block major ↵NeilBrown2005-08-26
| | | | | | | | | | 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>
* [PATCH] md: make sure resync gets started when array starts.NeilBrown2005-08-23
| | | | | | | | | | | | | 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>
* [PATCH] md: make sure mddev->bitmap_offset gets cleared between array ↵NeilBrown2005-08-18
| | | | | | | | | | | | | | | | 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>
* [PATCH] md: make sure md bitmap updates are flushed when array is stopped.NeilBrown2005-08-04
| | | | | | | | | | | | 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>
* [PATCH] md: make 'md' and alias for 'md-mod'NeilBrown2005-08-04
| | | | | | | | | | | | | 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>
* [PATCH] md: remove a stray debugging printk.NeilBrown2005-08-04
| | | | | | 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>
* [PATCH] clean up inline static vs static inlineJesper Juhl2005-07-27
| | | | | | | | | | | | | | | `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>
* [PATCH] md: bio leak fixNeil Brown2005-06-28
| | | | | | | | | | 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>
* [PATCH] Cleanup patch for process freezingChristoph Lameter2005-06-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] md: remove unneeded NULL checks before kfreeJesper Juhl2005-06-21
| | | | | | | | | | 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>
* [PATCH] Two small fixes for md verion-1 superblocks.NeilBrown2005-06-21
| | | | | | | | | | | | 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>
* [PATCH] md: allow md to update multiple superblocks in parallel.NeilBrown2005-06-21
| | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] md: allow md intent bitmap to be stored near the superblock.NeilBrown2005-06-21
| | | | | | | | | | | 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>
* [PATCH] md: fix deadlock due to md thread processing delayed requests.NeilBrown2005-06-21
| | | | | | | | | | | | | | | | | | | | 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>
* [PATCH] md: optimise reconstruction when re-adding a recently failed drive.NeilBrown2005-06-21
| | | | | | | | | | | | 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>
* [PATCH] md: call bitmap_daemon_work regularlyNeilBrown2005-06-21
| | | | | | | | | | | | 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>
* [PATCH] md: a couple of tidyups relating to the bitmap file.NeilBrown2005-06-21
| | | | | | | | | | 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>
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