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2010-06-24md: Don't update ->recovery_offset when reshaping an array to fewer devices.NeilBrown
When an array is reshaped to have fewer devices, the reshape proceeds from the end of the devices to the beginning. If a device happens to be non-In_sync (which is possible but rare) we would normally update the ->recovery_offset as the reshape progresses. However that would be wrong as the recover_offset records that the early part of the device is in_sync, while in fact it would only be the later part that is in_sync, and in any case the offset number would be measured from the wrong end of the device. Relatedly, if after a reshape a spare is discovered to not be recoverred all the way to the end, not allow spare_active to incorporate it in the array. This becomes relevant in the following sample scenario: A 4 drive RAID5 is converted to a 6 drive RAID6 in a combined operation. The RAID5->RAID6 conversion will cause a 5 drive to be included as a spare, then the 5drive -> 6drive reshape will effectively rebuild that spare as it progresses. The 6th drive is treated as in_sync the whole time as there is never any case that we might consider reading from it, but must not because there is no valid data. If we interrupt this reshape part-way through and reverse it to return to a 5-drive RAID6 (or event a 4-drive RAID5), we don't want to update the recovery_offset - as that would be wrong - and we don't want to include that spare as active in the 5-drive RAID6 when the reversed reshape completed and it will be mostly out-of-sync still. Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24md: fix handling of array level takeover that re-arranges devices.NeilBrown
Most array level changes leave the list of devices largely unchanged, possibly causing one at the end to become redundant. However conversions between RAID0 and RAID10 need to renumber all devices (except 0). This renumbering is currently being done in the ->run method when the new personality takes over. However this is too late as the common code in md.c might already have invalidated some of the devices if they had a ->raid_disk number that appeared to high. Moving it into the ->takeover method is too early as the array is still active at that time and wrong ->raid_disk numbers could cause confusion. So add a ->new_raid_disk field to mdk_rdev_s and use it to communicate the new raid_disk number. Now the common code knows exactly which devices need to be renumbered, and which can be invalidated, and can do it all at a convenient time when the array is suspend. It can also update some symlinks in sysfs which previously were not be updated correctly. Reported-by: Maciej Trela <maciej.trela@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-06-24Restore partition detection of newly created md arrays.NeilBrown
Commit b821eaa572fd737faaf6928ba046e571526c36c6 broke partition detection for md arrays. The logic was almost right. However if revalidate_disk is called when the device is not yet open, bdev->bd_disk won't be set, so the flush_disk() Call will not set bd_invalidated. So when md_open is called we still need to ensure that ->bd_invalidated gets set. This is easily done with a call to check_disk_size_change in the place where the offending commit removed check_disk_change. At the important times, the size will have changed from 0 to non-zero, so check_disk_size_change will set bd_invalidated. Tested-by: Duncan <1i5t5.duncan@cox.net> Reported-by: Duncan <1i5t5.duncan@cox.net> Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-21Merge commit '3ff195b011d7decf501a4d55aeed312731094796' into for-linusNeilBrown
Conflicts: drivers/md/md.c - Resolved conflict in md_update_sb - Added extra 'NULL' arg to new instance of sysfs_get_dirent. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-21sysfs: Implement sysfs tagged directory support.Eric W. Biederman
The problem. When implementing a network namespace I need to be able to have multiple network devices with the same name. Currently this is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and potentially a few other directories of the form /sys/ ... /net/*. What this patch does is to add an additional tag field to the sysfs dirent structure. For directories that should show different contents depending on the context such as /sys/class/net/, and /sys/devices/virtual/net/ this tag field is used to specify the context in which those directories should be visible. Effectively this is the same as creating multiple distinct directories with the same name but internally to sysfs the result is nicer. I am calling the concept of a single directory that looks like multiple directories all at the same path in the filesystem tagged directories. For the networking namespace the set of directories whose contents I need to filter with tags can depend on the presence or absence of hotplug hardware or which modules are currently loaded. Which means I need a simple race free way to setup those directories as tagged. To achieve a reace free design all tagged directories are created and managed by sysfs itself. Users of this interface: - define a type in the sysfs_tag_type enumeration. - call sysfs_register_ns_types with the type and it's operations - sysfs_exit_ns when an individual tag is no longer valid - Implement mount_ns() which returns the ns of the calling process so we can attach it to a sysfs superblock. - Implement ktype.namespace() which returns the ns of a syfs kobject. Everything else is left up to sysfs and the driver layer. For the network namespace mount_ns and namespace() are essentially one line functions, and look to remain that. Tags are currently represented a const void * pointers as that is both generic, prevides enough information for equality comparisons, and is trivial to create for current users, as it is just the existing namespace pointer. The work needed in sysfs is more extensive. At each directory or symlink creating I need to check if the directory it is being created in is a tagged directory and if so generate the appropriate tag to place on the sysfs_dirent. Likewise at each symlink or directory removal I need to check if the sysfs directory it is being removed from is a tagged directory and if so figure out which tag goes along with the name I am deleting. Currently only directories which hold kobjects, and symlinks are supported. There is not enough information in the current file attribute interfaces to give us anything to discriminate on which makes it useless, and there are no potential users which makes it an uninteresting problem to solve. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-18md: don't insist on valid event count for spare devices.NeilBrown
Devices which know that they are spares do not really need to have an event count that matches the rest of the array, so there are no data-in-sync issues. It is enough that the uuid matches. So remove the requirement that the event count is up-to-date. We currently still write out and event count on spares, but this allows us in a year or 3 to stop doing that completely. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: simplify updating of event count to sometimes avoid updating spares.NeilBrown
When updating the event count for a simple clean <-> dirty transition, we try to avoid updating the spares so they can safely spin-down. As the event_counts across an array must be +/- 1, this means decrementing the event_count on a dirty->clean transition. This is not always safe and we have to avoid the unsafe time. We current do this with a misguided idea about it being safe or not depending on whether the event_count is odd or even. This approach only works reliably in a few common instances, but easily falls down. So instead, simply keep internal state concerning whether it is safe or not, and always assume it is not safe when an array is first assembled. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: restore ability of spare drives to spin down.NeilBrown
Some time ago we stopped the clean/active metadata updates from being written to a 'spare' device in most cases so that it could spin down and say spun down. Device failure/removal etc are still recorded on spares. However commit 51d5668cb2e3fd1827a55 broke this 50% of the time, depending on whether the event count is even or odd. The change log entry said: This means that the alignment between 'odd/even' and 'clean/dirty' might take a little longer to attain, how ever the code makes no attempt to create that alignment, so it could take arbitrarily long. So when we find that clean/dirty is not aligned with odd/even, force a second metadata-update immediately. There are already cases where a second metadata-update is needed immediately (e.g. when a device fails during the metadata update). We just piggy-back on that. Reported-by: Joe Bryant <tenminjoe@yahoo.com> Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@kernel.org
2010-05-18md: allow integers to be passed to md/levelDan Williams
e.g. allow md to interpret 'echo 4 > md/level' as a request for raid4. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-18md: notify mdstat waiters of level changeDan Williams
Level modifications change the output of mdstat. The mdmon manager thread is interested in these events for external metadata management. Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2010-05-18md: don't unregister the thread in mddev_suspendNeilBrown
This is - unnecessary because mddev_suspend is always followed by a call to ->stop, and each ->stop unregisters the thread, and - a problem as it makes it awkwards to suspend and then resume a device as we will want later. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: factor out init code for an mddevNeilBrown
This is a simple factorisation that makes mddev_find easier to read. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: pass mddev to make_request functions rather than request_queueNeilBrown
We used to pass the personality make_request function direct to the block layer so the first argument had to be a queue. But now we have the intermediary md_make_request so it makes at lot more sense to pass a struct mddev_s. It makes it possible to have an mddev without its own queue too. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: call md_stop_writes from md_stopNeilBrown
This moves the call to the other side of set_readonly, but that should not be an issue. This encapsulates in 'md_stop' all of the functionality for internally stopping the array, leaving all the interactions with externalities (sysfs, request_queue, gendisk) in do_md_stop. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: split md_set_readonly out of do_md_stopNeilBrown
Using do_md_stop to set an array to read-only is a little confusing. Now most of the common code has been factored out, split md_set_readonly off in to a separate function. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: factor md_stop_writes out of do_md_stop.NeilBrown
Further refactoring of do_md_stop. This one requires some explanation as it takes code from different places in do_md_stop, so some re-ordering happens. We only get into this part of do_md_stop if there are no active opens of the device, so no writes can be happening and the device must have been flushed. In md_stop_writes we want to stop any internal sources of writes - i.e. resync - and flush out the metadata. The only code that was previously before some of this code is code to clean up the queue, the mddev, the gendisk, or sysfs, all of which is probably better after code that makes active changes (i.e. triggers writes). Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: start to refactor do_md_stopNeilBrown
do_md_stop is large and clunky, so hard to understand. This is a first step of refactoring, pulling two simple sub-functions out. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: factor do_md_run to separate accesses to ->gendiskNeilBrown
As part of relaxing the binding between an mddev and gendisk, we separate do_md_run into two functions. md_run does all the work internal to md do_md_run calls md_run and makes and changes to gendisk that are required. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: remove ->changed and related code.NeilBrown
We set ->changed to 1 and call check_disk_change at the end of md_open so that bd_invalidated would be set and thus partition rescan would happen appropriately. Now that we call revalidate_disk directly, which sets bd_invalidates, that indirection is no longer needed and can be removed. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: don't reference gendisk in getgeoNeilBrown
Using ->array_sectors rather than get_capacity() is more direct and is a step towards relaxing the tight connection between mddev and gendisk. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: move io accounting out of personalities into md_make_requestNeilBrown
While I generally prefer letting personalities do as much as possible, given that we have a central md_make_request anyway we may as well use it to simplify code. Also this centralises knowledge of ->gendisk which will help later. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: notify level changes through sysfs.Maciej Trela
Level changes can be very significant, so make sure to notify them via sysfs. Signed-off-by: Maciej Trela <maciej.trela@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: Relax checks on ->max_disks when external metadata handling is used.NeilBrown
When metadata is being managed by user-space, md doesn't know what the maximum number of devices allowed in an array is so ->max_disks is 0. In this case we should allow any (+ve) number of disks. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: Correctly handle device removal via sysfsMaciej Trela
Writing "none" to "../md/dev-xx/slot" removes that device from being an active part of the array, but it didn't set ->raid_disk to -1 to record this fact. Signed-off-by: Maciej Trela <Maciej.Trela@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: Add support for Raid5->Raid0 and Raid10->Raid0 takeoverTrela, Maciej
Signed-off-by: Maciej Trela <maciej.trela@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md:Add support for Raid0->Raid5 takeoverTrela Maciej
Signed-off-by: Maciej Trela <maciej.trela@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-18md: discard StateChanged device flag.NeilBrown
This was needed when sysfs files could only be 'notified' from process context. Now that we have sys_notify_direct, we can call it directly from an interrupt. Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-17md: manage redundancy group in sysfs when changing level.NeilBrown
Some levels expect the 'redundancy group' to be present, others don't. So when we change level of an array we might need to add or remove this group. This requires fixing up the current practice of overloading ->private to indicate (when ->pers == NULL) that something needs to be removed. So create a new ->to_remove to fill that role. When changing levels, we may need to add or remove attributes. When changing RAID5 -> RAID6, we both add and remove the same thing. It is important to catch this and optimise it out as the removal is delayed until a lock is released, so trying to add immediately would cause problems. Cc: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-17md: remove unneeded sysfs files more promptlyNeilBrown
When an array is stopped we need to remove some sysfs files which are dependent on the type of array. We need to delay that deletion as deleting them while holding reconfig_mutex can lead to deadlocks. We currently delay them until the array is completely destroyed. However it is possible to deactivate and then reactivate the array. It is also possible to need to remove sysfs files when changing level, which can potentially happen several times before an array is destroyed. So we need to delete these files more promptly: as soon as reconfig_mutex is dropped. We need to ensure this happens before do_md_run can restart the array, so we use open_mutex for some extra locking. This is not deadlock prone. Cc: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-11md: set mddev readonly flag on blkdev BLKROSET ioctlDan Williams
When the user sets the block device to readwrite then the mddev should follow suit. Otherwise, the BUG_ON in md_write_start() will be set to trigger. The reverse direction, setting mddev->ro to match a set readonly request, can be ignored because the blkdev level readonly flag precludes the need to have mddev->ro set correctly. Nevermind the fact that setting mddev->ro to 1 may fail if the array is in use. Cc: <stable@kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-05-07md: restore ability of spare drives to spin down.NeilBrown
Some time ago we stopped the clean/active metadata updates from being written to a 'spare' device in most cases so that it could spin down and say spun down. Device failure/removal etc are still recorded on spares. However commit 51d5668cb2e3fd1827a55 broke this 50% of the time, depending on whether the event count is even or odd. The change log entry said: This means that the alignment between 'odd/even' and 'clean/dirty' might take a little longer to attain, how ever the code makes no attempt to create that alignment, so it could take arbitrarily long. So when we find that clean/dirty is not aligned with odd/even, force a second metadata-update immediately. There are already cases where a second metadata-update is needed immediately (e.g. when a device fails during the metadata update). We just piggy-back on that. Reported-by: Joe Bryant <tenminjoe@yahoo.com> Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@kernel.org
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-08Driver core: Constify struct sysfs_ops in struct kobj_typeEmese Revfy
Constify struct sysfs_ops. This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy <re.emese@gmail.com> Acked-by: David Teigland <teigland@redhat.com> Acked-by: Matt Domsch <Matt_Domsch@dell.com> Acked-by: Maciej Sosnowski <maciej.sosnowski@intel.com> Acked-by: Hans J. Koch <hjk@linutronix.de> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Jens Axboe <jens.axboe@oracle.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-02-10md: fix some lockdep issues between md and sysfs.NeilBrown
====== This fix is related to http://bugzilla.kernel.org/show_bug.cgi?id=15142 but does not address that exact issue. ====== sysfs does like attributes being removed while they are being accessed (i.e. read or written) and waits for the access to complete. As accessing some md attributes takes the same lock that is held while removing those attributes a deadlock can occur. This patch addresses 3 issues in md that could lead to this deadlock. Two relate to calling flush_scheduled_work while the lock is held. This is probably a bad idea in general and as we use schedule_work to delete various sysfs objects it is particularly bad. In one case flush_scheduled_work is called from md_alloc (called by md_probe) called from do_md_run which holds the lock. This call is only present to ensure that ->gendisk is set. However we can be sure that gendisk is always set (though possibly we couldn't when that code was originally written. This is because do_md_run is called in three different contexts: 1/ from md_ioctl. This requires that md_open has succeeded, and it fails if ->gendisk is not set. 2/ from writing a sysfs attribute. This can only happen if the mddev has been registered in sysfs which happens in md_alloc after ->gendisk has been set. 3/ from autorun_array which is only called by autorun_devices, which checks for ->gendisk to be set before calling autorun_array. So the call to md_probe in do_md_run can be removed, and the check on ->gendisk can also go. In the other case flush_scheduled_work is being called in do_md_stop, purportedly to wait for all md_delayed_delete calls (which delete the component rdevs) to complete. However there really isn't any need to wait for them - they have already been disconnected in all important ways. The third issue is that raid5->stop() removes some attribute names while the lock is held. There is already some infrastructure in place to delay attribute removal until after the lock is released (using schedule_work). So extend that infrastructure to remove the raid5_attrs_group. This does not address all lockdep issues related to the sysfs "s_active" lock. The rest can be address by splitting that lockdep context between symlinks and non-symlinks which hopefully will happen. Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30md: allow a resync that is waiting for other resync to complete, to be aborted.NeilBrown
If two arrays share a device, then they will not both resync at the same time. One will wait for the other to complete. While waiting, the MD_RECOVERY_INTR flag is not checked so a device failure, which would make the resync pointless, does not cause the resync to abort, so the failed device cannot be removed (as it cannot be remove while a resync is happening). So add a test for MD_RECOVERY_INTR. Reported-by: Brett Russ <bruss@netezza.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30md: remove unnecessary code from do_md_runNeilBrown
Since commit dfc7064500061677720fa26352963c772d3ebe6b, ->hot_remove_disks has not removed non-failed devices from an array until recovery is no longer possible. So the code in do_md_run to get around the fact that md_check_recovery (which calls ->hot_remove_disks) would remove partially-in-sync devices is no longer needed. So remove it. Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30md: make recovery started by do_md_run() visible via sync_actionDan Williams
By default md_do_sync() will perform recovery if no other actions are specified. However, action_show() relies on MD_RECOVERY_RECOVER to be set otherwise it returns 'idle'. So, add a missing set MD_RECOVERY_RECOVER when starting recovery. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30md: fix small irregularity with start_ro module parameterNeilBrown
The start_ro modules parameter can be used to force arrays to be started in 'auto-readonly' in which they are read-only until the first write. This ensures that no resync/recovery happens until something else writes to the device. This is important for resume-from-disk off an md array. However if an array is started 'readonly' (by writing 'readonly' to the 'array_state' sysfs attribute) we want it to be really 'readonly', not 'auto-readonly'. So strengthen the condition to only set auto-readonly if the array is not already read-only. Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-30md: Fix unfortunate interaction with evmsNeilBrown
evms configures md arrays by: open device send ioctl close device for each different ioctl needed. Since 2.6.29, the device can disappear after the 'close' unless a significant configuration has happened to the device. The change made by "SET_ARRAY_INFO" can too minor to stop the device from disappearing, but important enough that losing the change is bad. So: make sure SET_ARRAY_INFO sets mddev->ctime, and keep the device active as long as ctime is non-zero (it gets zeroed with lots of other things when the array is stopped). This is suitable for -stable kernels since 2.6.29. Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@kernel.org
2009-12-15drivers/md/md.c: use %pU to print UUIDsJoe Perches
Signed-off-by: Joe Perches <joe@perches.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15tree-wide: convert open calls to remove spaces to skip_spaces() lib functionAndré Goddard Rosa
Makes use of skip_spaces() defined in lib/string.c for removing leading spaces from strings all over the tree. It decreases lib.a code size by 47 bytes and reuses the function tree-wide: text data bss dec hex filename 64688 584 592 65864 10148 (TOTALS-BEFORE) 64641 584 592 65817 10119 (TOTALS-AFTER) Also, while at it, if we see (*str && isspace(*str)), we can be sure to remove the first condition (*str) as the second one (isspace(*str)) also evaluates to 0 whenever *str == 0, making it redundant. In other words, "a char equals zero is never a space". Julia Lawall tried the semantic patch (http://coccinelle.lip6.fr) below, and found occurrences of this pattern on 3 more files: drivers/leds/led-class.c drivers/leds/ledtrig-timer.c drivers/video/output.c @@ expression str; @@ ( // ignore skip_spaces cases while (*str && isspace(*str)) { \(str++;\|++str;\) } | - *str && isspace(*str) ) Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Cc: Julia Lawall <julia@diku.dk> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Richard Purdie <rpurdie@rpsys.net> Cc: Neil Brown <neilb@suse.de> Cc: Kyle McMartin <kyle@mcmartin.ca> Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Cc: David Howells <dhowells@redhat.com> Cc: <linux-ext4@vger.kernel.org> Cc: Samuel Ortiz <samuel@sortiz.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Takashi Iwai <tiwai@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-14md: add 'recovery_start' per-device sysfs attributeDan Williams
Enable external metadata arrays to manage rebuild checkpointing via a md/dev-XXX/recovery_start attribute which reflects rdev->recovery_offset Also update resync_start_store to allow 'none' to be written, for consistency. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: rcu_read_lock() walk of mddev->disks in md_do_sync()Dan Williams
Other walks of this list are either under rcu_read_lock() or the list mutation lock (mddev_lock()). This protects against the improbable case of a disk being removed from the array at the start of md_do_sync(). Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-12-14md: integrate spares into array at earliest opportunity.NeilBrown
As v1.x metadata can record that a member of the array is not completely recovered, it make sense to record that a spare has become a regular member of the array at the earliest opportunity. So remove the tests on "recovery_offset > 0" in super_1_sync as they really aren't needed, and schedule a metadata update immediately after adding spares to a degraded array. This means that if a crash happens immediately after a recovery starts, the new device will be included in the array and recovery will continue from wherever it was up to. Previously this didn't happen unless recovery was at least 1/16 of the way through. Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: move compat_ioctl handling into md.cArnd Bergmann
The RAID ioctls are only implemented in md.c, so the handling for them should also be moved there from fs/compat_ioctl.c. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Neil Brown <neilb@suse.de> Cc: Andre Noll <maan@systemlinux.org> Cc: linux-raid@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: add MODULE_DESCRIPTION for all md related modules.NeilBrown
Suggested by Oren Held <orenhe@il.ibm.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14raid: improve MD/raid10 handling of correctable read errors.Robert Becker
We've noticed severe lasting performance degradation of our raid arrays when we have drives that yield large amounts of media errors. The raid10 module will queue each failed read for retry, and also will attempt call fix_read_error() to perform the read recovery. Read recovery is performed while the array is frozen, so repeated recovery attempts can degrade the performance of the array for extended periods of time. With this patch I propose adding a per md device max number of corrected read attempts. Each rdev will maintain a count of read correction attempts in the rdev->read_errors field (not used currently for raid10). When we enter fix_read_error() we'll check to see when the last read error occurred, and divide the read error count by 2 for every hour since the last read error. If at that point our read error count exceeds the read error threshold, we'll fail the raid device. In addition in this patch I add sysfs nodes (get/set) for the per md max_read_errors attribute, the rdev->read_errors attribute, and added some printk's to indicate when fix_read_error fails to repair an rdev. For testing I used debugfs->fail_make_request to inject IO errors to the rdev while doing IO to the raid array. Signed-off-by: Robert Becker <Rob.Becker@riverbed.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: support updating bitmap parameters via sysfs.NeilBrown
A new attribute directory 'bitmap' in 'md' is created which contains files for configuring the bitmap. 'location' identifies where the bitmap is, either 'none', or 'file' or 'sector offset from metadata'. Writing 'location' can create or remove a bitmap. Adding a 'file' bitmap this way is not yet supported. 'chunksize' and 'time_base' must be set before 'location' can be set. 'chunksize' can be set before creating a bitmap, but is currently always over-ridden by the bitmap superblock. 'time_base' and 'backlog' can be updated at any time. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Andre Noll <maan@systemlinux.org>
2009-12-14md: factor out parsing of fixed-point numbersNeilBrown
safe_delay_store can parse fixed point numbers (for fractions of a second). We will want to do that for another sysfs file soon, so factor out the code. Signed-off-by: NeilBrown <neilb@suse.de>
2009-12-14md: move offset, daemon_sleep and chunksize out of bitmap structureNeilBrown
... and into bitmap_info. These are all configuration parameters that need to be set before the bitmap is created. Signed-off-by: NeilBrown <neilb@suse.de>