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path: root/drivers/md/md.c
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2009-07-01md: use interruptible wait when duration is controlled by userspace.NeilBrown
User space can set various limits on an md array so that resync waits when it gets to a certain point, or so that I/O is blocked for a short while. When md is waiting against one of these limit, it should use an interruptible wait so as not to add to the load average, and so are not to trigger a warning if the wait goes on for too long. Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01md: tidy up error paths in md_allocNeilBrown
As the recent bug in md_alloc showed, having a single exit path for unlocking and putting is a good idea. So restructure md_alloc to have a single mutex_unlock and mddev_put, and use gotos where necessary. Found-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01md: fix error path when duplicate name is found on md device creation.NeilBrown
When an md device is created by name (rather than number) we need to check that the name is not already in use. If this check finds a duplicate, we return an error without dropping the lock or freeing the newly create mddev. This patch fixes that. Cc: stable@kernel.org Found-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-07-01md: avoid dereferencing NULL pointer when accessing suspend_* sysfs attributes.NeilBrown
If we try to modify one of the md/ sysfs files suspend_lo or suspend_hi when the array is not active, we dereference a NULL. Protect against that. Cc: stable@kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: Move check for bitmap presence to personality code.Andre Noll
If the superblock of a component device indicates the presence of a bitmap but the corresponding raid personality does not support bitmaps (raid0, linear, multipath, faulty), then something is seriously wrong and we'd better refuse to run such an array. Currently, this check is performed while the superblocks are examined, i.e. before entering personality code. Therefore the generic md layer must know which raid levels support bitmaps and which do not. This patch avoids this layer violation without adding identical code to various personalities. This is accomplished by introducing a new public function to md.c, md_check_no_bitmap(), which replaces the hard-coded checks in the superblock loading functions. A call to md_check_no_bitmap() is added to the ->run method of each personality which does not support bitmaps and assembly is aborted if at least one component device contains a bitmap. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: remove chunksize rounding from common code.NeilBrown
It is easiest to round sizes to multiples of chunk size in the personality code for those personalities which care. Those personalities now do the rounding, so we can remove that function from common code. Also remove the upper bound on the size of a chunk, and the lower bound on the size of a device (1 chunk), neither of which really buy us anything. Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: move assignment of ->utime so that it never gets skipped.NeilBrown
Currently the assignment to utime gets skipped for 'external' metadata. So move it to the top of the function so that it always gets effected. This is of largely cosmetic interest. Nothing actually depends on ->utime being right for external arrays. "mdadm --monitor" does use it for 0.90 and 1.x arrays, but with mdadm-3.0, this is not important for external metadata. Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: Push down reconstruction log message to personality code.Andre Noll
Currently, the md layer checks in analyze_sbs() if the raid level supports reconstruction (mddev->level >= 1) and if reconstruction is in progress (mddev->recovery_cp != MaxSector). Move that printk into the personality code of those raid levels that care (levels 1, 4, 5, 6, 10). Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: merge reconfig and check_reshape methods.NeilBrown
The difference between these two methods is artificial. Both check that a pending reshape is valid, and perform any aspect of it that can be done immediately. 'reconfig' handles chunk size and layout. 'check_reshape' handles raid_disks. So make them just one method. Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: remove unnecessary arguments from ->reconfig method.NeilBrown
Passing the new layout and chunksize as args is not necessary as the mddev has fields for new_check and new_layout. This is preparation for combining the check_reshape and reconfig methods Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: Convert mddev->new_chunk to sectors.Andre Noll
A straight-forward conversion which gets rid of some multiplications/divisions/shifts. The patch also introduces a couple of new ones, most of which are due to conf->chunk_size still being represented in bytes. This will be cleaned up in subsequent patches. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-18md: Make mddev->chunk_size sector-based.Andre Noll
This patch renames the chunk_size field to chunk_sectors with the implied change of semantics. Since is_power_of_2(chunk_size) = is_power_of_2(chunk_sectors << 9) = is_power_of_2(chunk_sectors) these bits don't need an adjustment for the shift. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-16md: prepare for non-power-of-two chunk sizesraz ben yehuda
Remove chunk size check from md as this is now performed in the run function in each personality. Replace chunk size power 2 code calculations by a regular division. Signed-off-by: raziebe@gmail.com Signed-off-by: NeilBrown <neilb@suse.de>
2009-06-11Merge branch 'for-2.6.31' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.31' of git://git.kernel.dk/linux-2.6-block: (153 commits) block: add request clone interface (v2) floppy: fix hibernation ramdisk: remove long-deprecated "ramdisk=" boot-time parameter fs/bio.c: add missing __user annotation block: prevent possible io_context->refcount overflow Add serial number support for virtio_blk, V4a block: Add missing bounce_pfn stacking and fix comments Revert "block: Fix bounce limit setting in DM" cciss: decode unit attention in SCSI error handling code cciss: Remove no longer needed sendcmd reject processing code cciss: change SCSI error handling routines to work with interrupts enabled. cciss: separate error processing and command retrying code in sendcmd_withirq_core() cciss: factor out fix target status processing code from sendcmd functions cciss: simplify interface of sendcmd() and sendcmd_withirq() cciss: factor out core of sendcmd_withirq() for use by SCSI error handling code cciss: Use schedule_timeout_uninterruptible in SCSI error handling code block: needs to set the residual length of a bidi request Revert "block: implement blkdev_readpages" block: Fix bounce limit setting in DM Removed reference to non-existing file Documentation/PCI/PCI-DMA-mapping.txt ... Manually fix conflicts with tracing updates in: block/blk-sysfs.c drivers/ide/ide-atapi.c drivers/ide/ide-cd.c drivers/ide/ide-floppy.c drivers/ide/ide-tape.c include/trace/events/block.h kernel/trace/blktrace.c
2009-05-26md: don't use locked_ioctl.NeilBrown
md has no need for the BKL - it does its own locking. So md_ioctl doesn't need to be a locked_ioctl. Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26md: don't update curr_resync_completed without also updating reshape_position.NeilBrown
In order for the metadata to always be consistent, we mustn't updated curr_resync_completed without also updating reshape_position. The reshape code updates both at the same time. However since commit 97e4f42d62badb0f9fbc27c013e89bc1336a03bc the common md_do_sync will sometimes update curr_resync_completed but is not in a position to update reshape_position. So if MD_RECOVERY_RESHAPE is set (indicating that a reshape is happening, so reshape_position might change), don't update curr_resync_completed in md_do_sync, leave it to the per-personality reshape code. Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26md: export 'frozen' resync state through sysfsNeilBrown
The md resync engine has a 'frozen' state which ensures that no resync/recovery. This is used to avoid races. Export this state through the 'sync_action' sysfs attribute so that user-space can benefit and also avoid some races. Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26md: improve errno return when setting array_sizeNeilBrown
Instead of always returns EINVAL if anything goes wrong when setting the array size, add the option of E2BIG if the size requested is too large. This makes it easier for user-space to be sure what went wrong. Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-26md: always update level / chunk_size / layout when writing v1.x metadata.NeilBrown
We previously didn't update these fields when writing the metadata because they could never change. They can now, so we better write them. v0.90 metadata always updated these fields. Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-22block: Do away with the notion of hardsect_sizeMartin K. Petersen
Until now we have had a 1:1 mapping between storage device physical block size and the logical block sized used when addressing the device. With SATA 4KB drives coming out that will no longer be the case. The sector size will be 4KB but the logical block size will remain 512-bytes. Hence we need to distinguish between the physical block size and the logical ditto. This patch renames hardsect_size to logical_block_size. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-05-07md: remove rd%d links immediately after stopping an array.NeilBrown
md maintains link in sys/mdXX/md/ to identify which device has which role in the array. e.g. rd2 -> dev-sda indicates that the device with role '2' in the array is sda. These links are only present when the array is active. They are created immediately after ->run is called, and so should be removed immediately after ->stop is called. However they are currently removed a little bit later, and it is possible for ->run to be called again, thus adding these links, before they are removed. So move the removal earlier so they are consistently only present when the array is active. Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07md: remove ability to explicit set an inactive array to 'clean'.NeilBrown
Being able to write 'clean' to an 'array_state' of an inactive array to activate it in 'clean' mode is both unnecessary and inconvenient. It is unnecessary because the same can be achieved by writing 'active'. This activates and array, but it still remains 'clean' until the first write. It is inconvenient because writing 'clean' is more often used to cause an 'active' array to revert to 'clean' mode (thus blocking any writes until a 'write-pending' is promoted to 'active'). Allowing 'clean' to both activate an array and mark an active array as clean can lead to races: One program writes 'clean' to mark the active array as clean at the same time as another program writes 'inactive' to deactivate (stop) and active array. Depending on which writes first, the array could be deactivated and immediately reactivated which isn't what was desired. So just disable the use of 'clean' to activate an array. This avoids a race that can be triggered with mdadm-3.0 and external metadata, so it suitable for -stable. Reported-by: Rafal Marszewski <rafal.marszewski@intel.com> Acked-by: Dan Williams <dan.j.williams@intel.com> Cc: <stable@kernel.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07md: constify VFTsJan Engelhardt
Signed-off-by: Jan Engelhardt <jengelh@medozas.de> Signed-off-by: NeilBrown <neilb@suse.de>
2009-05-07md: tidy up status_resync to handle large arrays.NeilBrown
Two problems in status_resync. 1/ It still used Kilobytes as the basic block unit, while most code now uses sectors uniformly. 2/ It doesn't allow for the possibility that max_sectors exceeds the range of "unsigned long". So - change "max_blocks" to "max_sectors", and store sector numbers in there and in 'resync' - Make 'rt' a 'sector_t' so it can temporarily hold the number of remaining sectors. - use sector_div rather than normal division. - change the magic '100' used to preserve precision to '32'. + making it a power of 2 makes division easier + it doesn't need to be as large as it was chosen when we averaged speed over the entire run. Now we average speed over the last 30 seconds or so. Reported-by: "Mario 'BitKoenig' Holbe" <Mario.Holbe@TU-Ilmenau.DE> Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-17md: update sync_completed and reshape_position even more often.NeilBrown
There are circumstances when a user-space process might need to "oversee" a resync/reshape process. For example when doing an in-place reshape of a raid5, it is prudent to take a backup of each section before reshaping it as this is the only way to provide safety against an unplanned shutdown (i.e. crash/power failure). The sync_max sysfs value can be used to stop the resync from advancing beyond a particular point. So user-space can: suspend IO to the first section and back it up set 'sync_max' to the end of the section wait for 'sync_completed' to reach that point resume IO on the first section and move on to the next section. However this process requires the kernel and user-space to run in lock-step which could introduce unnecessary delays. It would be better if a 'double buffered' approach could be used with userspace and kernel space working on different sections with the 'next' section always ready when the 'current' section is finished. One problem with implementing this is that sync_completed is only guaranteed to be updated when the sync process reaches sync_max. (it is updated on a time basis at other times, but it is hard to rely on that). This defeats some of the double buffering. With this patch, sync_completed (and reshape_position) get updated as the current position approaches sync_max, so there is room for userspace to advance sync_max early without losing updates. To be precise, sync_completed is updated when the current sync position reaches half way between the current value of sync_completed and the value of sync_max. This will usually be a good time for user space to update sync_max. If sync_max does not get updated, the updates to sync_completed (together with associated metadata updates) will occur at an exponentially increasing frequency which will get unreasonably fast (one update every page) immediately before the process hits sync_max and stops. So the update rate will be unreasonably fast only for an insignificant period of time. Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-14md: improve usefulness and accuracy of sysfs file md/sync_completed.NeilBrown
The sync_completed file reports how much of a resync (or recovery or reshape) has been completed. However due to the possibility of out-of-order completion of writes, it is not certain to be accurate. We have an internal value - mddev->curr_resync_completed - which is an accurate value (though it might not always be quite so uptodate). So: - make curr_resync_completed be uptodate a little more often, particularly when raid5 reshape updates status in the metadata - report curr_resync_completed in the sysfs file - allow poll/select to report all updates to md/sync_completed. This makes sync_completed completed usable by any external metadata handler that wants to record this status information in its metadata. Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-14md: allow setting newly added device to 'in_sync' via sysfs.NeilBrown
When adding devices to an active array via sysfs, there is currently no way to mark a device as 'in-sync' which is useful when incrementally assembling an array. So add that option. Signed-off-by: NeilBrown <neilb@suse.de>
2009-04-03Merge branch 'for-linus' of git://neil.brown.name/mdLinus Torvalds
* 'for-linus' of git://neil.brown.name/md: (53 commits) md/raid5 revise rules for when to update metadata during reshape md/raid5: minor code cleanups in make_request. md: remove CONFIG_MD_RAID_RESHAPE config option. md/raid5: be more careful about write ordering when reshaping. md: don't display meaningless values in sysfs files resync_start and sync_speed md/raid5: allow layout and chunksize to be changed on active array. md/raid5: reshape using largest of old and new chunk size md/raid5: prepare for allowing reshape to change layout md/raid5: prepare for allowing reshape to change chunksize. md/raid5: clearly differentiate 'before' and 'after' stripes during reshape. Documentation/md.txt update md: allow number of drives in raid5 to be reduced md/raid5: change reshape-progress measurement to cope with reshaping backwards. md: add explicit method to signal the end of a reshape. md/raid5: enhance raid5_size to work correctly with negative delta_disks md/raid5: drop qd_idx from r6_state md/raid6: move raid6 data processing to raid6_pq.ko md: raid5 run(): Fix max_degraded for raid level 4. md: 'array_size' sysfs attribute md: centralize ->array_sectors modifications ...
2009-03-31md: don't display meaningless values in sysfs files resync_start and sync_speedNeilBrown
When no resync if happening, both of these files currently have meaningless values (is slightly different ways). Change them to "none" in that case. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: add explicit method to signal the end of a reshape.NeilBrown
Currently raid5 (the only module that supports restriping) notices that the reshape has finished be sync_request being given a large value, and handles any cleanup them. This patch changes it so md_check_recovery calls into an explicit finish_reshape method as well. The clean-up from sync_request can do things that need to be done promptly, typically things local to the raid5_conf_t structure. The "finish_reshape" method is called under the mddev_lock so it can do things involving reconfiguring the device. This allows us to get rid of md_set_array_sectors_locked, which would have caused a deadlock if you tried to stop and array while a reshape was happening. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: 'array_size' sysfs attributeDan Williams
Allow userspace to set the size of the array according to the following semantics: 1/ size must be <= to the size returned by mddev->pers->size(mddev, 0, 0) a) If size is set before the array is running, do_md_run will fail if size is greater than the default size b) A reshape attempt that reduces the default size to less than the set array size should be blocked 2/ once userspace sets the size the kernel will not change it 3/ writing 'default' to this attribute returns control of the size to the kernel and reverts to the size reported by the personality Also, convert locations that need to know the default size from directly reading ->array_sectors to <pers>_size. Resync/reshape operations always follow the default size. Finally, fixup other locations that read a number of 1k-blocks from userspace to use strict_blocks_to_sectors() which checks for unsigned long long to sector_t overflow and blocks to sectors overflow. Reviewed-by: Andre Noll <maan@systemlinux.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31md: centralize ->array_sectors modificationsDan Williams
Get personalities out of the business of directly modifying ->array_sectors. Lays groundwork to introduce policy on when ->array_sectors can be modified. Reviewed-by: Andre Noll <maan@systemlinux.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-03-31md/raid5: allow layout/chunksize to be changed on an active 2-drive raid5.NeilBrown
2-drive raid5's aren't very interesting. But if you are converting a raid1 into a raid5, you will at least temporarily have one. And that it a good time to set the layout/chunksize for the new RAID5 if you aren't happy with the defaults. layout and chunksize don't actually affect the placement of data on a 2-drive raid5, so we just do some internal book-keeping. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: add ->takeover method to support changing the personality managing an arrayNeilBrown
Implement this for RAID6 to be able to 'takeover' a RAID5 array. The new RAID6 will use a layout which places Q on the last device, and that device will be missing. If there are any available spares, one will immediately have Q recovered onto it. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: enable suspend/resume of md devices.NeilBrown
To be able to change the 'level' of an md/raid array, we need to suspend the device so that no requests are active - then move some pointers around etc. The code already keeps counts of active requests and the ->quiesce function can be used to wait until those counts hit zero. However the quiesce function blocks new requests once they are all ready 'inside' the personality module, and that is too late if we want to replace the personality modules. So make all md requests come in through a common md_make_request function that keeps track of how many requests have entered the modules but may not yet be on the internal reference counts. Allow md_make_request to be blocked when we want to suspend the device, and make it possible to wait for all those in-transit requests to be added to internal lists so that ->quiesce can wait for them. There is still a problem that when a request completes, we drop the ref count inside the personality code so there is a short time between when the refcount hits zero, and when the personality code is no longer being used. The personality code never blocks (schedule or spinlock) between dropping the refcount and exiting the routine, so this should be safe (as put_module calls synchronize_sched() before unmapping the module code). Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: md_unregister_thread should cope with being passed NULLNeilBrown
Mostly md_unregister_thread is only called when we know that the thread is NULL, but sometimes we need to check first. It is safer to put the check inside md_unregister_thread itself. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: make sure new_level, new_chunksize, new_layout always have sensible values.NeilBrown
When an md array is undergoing a change, we have new_* fields that show the new values. When no change is happening, it is least confusing if these have the same value as the normal fields. This is true in most cases, but not when the values are set via sysfs. So fix this up. A subsequent patch will BUG_ON if these things aren't consistent. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: Represent raid device size in sectors.Andre Noll
This patch renames the "size" field of struct mdk_rdev_s to "sectors" and changes this field to store sectors instead of blocks. All users of this field, linear.c, raid0.c and md.c, are fixed up accordingly which gets rid of many multiplications and divisions. Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: Make mddev->size sector-based.Andre Noll
This patch renames the "size" field of struct mddev_s to "dev_sectors" and stores the number of 512-byte sectors instead of the number of 1K-blocks in it. All users of that field, including raid levels 1,4-6,10, are adjusted accordingly. This simplifies the code a bit because it allows to get rid of a couple of divisions/multiplications by two. In order to make checkpatch happy, some minor coding style issues have also been addressed. In particular, size_store() now uses strict_strtoull() instead of simple_strtoull(). Signed-off-by: Andre Noll <maan@systemlinux.org> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: be more consistent about setting WriteMostly flag when adding a drive to ↵NeilBrown
an array When a drive is added to an array using ADD_NEW_DISK, there are two places we can get certain flags from: the metadata on the disk or the flags passed through the IOCTL. For the WriteMostly flag (aka MD_DISK_WRITEMOSTLY) we take the value from either of those sources depending on if it is set (i.e. we effectively 'or' the two sources together). This makes it awkward to clear, and is at best inconsistent. As documented code (in mdadm) requires that setting MD_DISK_WRITEMOSTLY in the ioctl will be effective, we resolve the inconsistency by always using the value for this flag from the ioctl, and ignoring the value on disk. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: occasionally checkpoint drive recovery to reduce duplicate effort after ↵NeilBrown
a crash Version 1.x metadata has the ability to record the status of a partially completed drive recovery. However we only update that record on a clean shutdown. It would be nice to update it on unclean shutdowns too, particularly when using a bitmap that removes much to the 'sync' effort after an unclean shutdown. One complication with checkpointing recovery is that we only know where we are up to in terms of IO requests started, not which ones have completed. And we need to know what has completed to record how much is recovered. So occasionally pause the recovery until all submitted requests are completed, then update the record of where we are up to. When we have a bitmap, we already do that pause occasionally to keep the bitmap up-to-date. So enhance that code to record the recovery offset and schedule a superblock update. And when there is no bitmap, just pause 16 times during the resync to do a checkpoint. '16' is a fairly arbitrary number. But we don't really have any good way to judge how often is acceptable, and it seems like a reasonable number for now. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move md_k.h from include/linux/raid/ to drivers/md/NeilBrown
It really is nicer to keep related code together.. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move lots of #include lines out of .h files and into .cNeilBrown
This makes the includes more explicit, and is preparation for moving md_k.h to drivers/md/md.h Remove include/raid/md.h as its only remaining use was to #include other files. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move LEVEL_* definition from md_k.h to md_u.hNeilBrown
.. as they are part of the user-space interface. Also move MdpMinorShift into there so we can remove duplication. Lastly move mdp_major in. It is less obviously part of the user-space interface, but do_mounts_md.c uses it, and it is acting a bit like user-space. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: move headers out of include/linux/raid/Christoph Hellwig
Move the headers with the local structures for the disciplines and bitmap.h into drivers/md/ so that they are more easily grepable for hacking and not far away. md.h is left where it is for now as there are some uses from the outside. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: stop defining MAJOR_NRChristoph Hellwig
MAJOR_NR was only required for magic in linux/blk.h in 2.4 or earlier kernels, so no need to keep it around. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31MD data integrity supportMartin K. Petersen
md: Add support for data integrity to MD If all subdevices support the same protection format the MD device is flagged as integrity capable. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-31md: Fix is_mddev_idle test (again).NeilBrown
There are two problems with is_mddev_idle. 1/ sync_io is 'atomic_t' and hence 'int'. curr_events and all the rest are 'long'. So if sync_io were to wrap on a 64bit host, the value of curr_events would go very negative suddenly, and take a very long time to return to positive. So do all calculations as 'int'. That gives us plenty of precision for what we need. 2/ To initialise rdev->last_events we simply call is_mddev_idle, on the assumption that it will make sure that last_events is in a suitable range. It used to do this, but now it does not. So now we need to be more explicit about initialisation. Signed-off-by: NeilBrown <neilb@suse.de>
2009-03-04md: fix deadlock when stopping arraysDan Williams
Resolve a deadlock when stopping redundant arrays, i.e. ones that require a call to sysfs_remove_group when shutdown. The deadlock is summarized below: Thread1 Thread2 ------- ------- read sysfs attribute stop array take mddev lock sysfs_remove_group sysfs_get_active wait for mddev lock wait for active Sysrq-w: -------- mdmon S 00000017 2212 4163 1 f1982ea8 00000046 2dcf6b85 00000017 c0b23100 f2f83ed0 c0b23100 f2f8413c c0b23100 c0b23100 c0b1fb98 f2f8413c 00000000 f2f8413c c0b23100 f2291ecc 00000002 c0b23100 00000000 00000017 f2f83ed0 f1982eac 00000046 c044d9dd Call Trace: [<c044d9dd>] ? debug_mutex_add_waiter+0x1d/0x58 [<c06ef451>] __mutex_lock_common+0x1d9/0x338 [<c06ef451>] ? __mutex_lock_common+0x1d9/0x338 [<c06ef5e3>] mutex_lock_interruptible_nested+0x33/0x3a [<c0634553>] ? mddev_lock+0x14/0x16 [<c0634553>] mddev_lock+0x14/0x16 [<c0634eda>] md_attr_show+0x2a/0x49 [<c04e9997>] sysfs_read_file+0x93/0xf9 mdadm D 00000017 2812 4177 1 f0401d78 00000046 430456f8 00000017 f0401d58 f0401d20 c0b23100 f2da2c4c c0b23100 c0b23100 c0b1fb98 f2da2c4c 0a10fc36 00000000 c0b23100 f0401d70 00000003 c0b23100 00000000 00000017 f2da29e0 00000001 00000002 00000000 Call Trace: [<c06eed1b>] schedule_timeout+0x1b/0x95 [<c06eed1b>] ? schedule_timeout+0x1b/0x95 [<c06eeb97>] ? wait_for_common+0x34/0xdc [<c044fa8a>] ? trace_hardirqs_on_caller+0x18/0x145 [<c044fbc2>] ? trace_hardirqs_on+0xb/0xd [<c06eec03>] wait_for_common+0xa0/0xdc [<c0428c7c>] ? default_wake_function+0x0/0x12 [<c06eeccc>] wait_for_completion+0x17/0x19 [<c04ea620>] sysfs_addrm_finish+0x19f/0x1d1 [<c04e920e>] sysfs_hash_and_remove+0x42/0x55 [<c04eb4db>] sysfs_remove_group+0x57/0x86 [<c0638086>] do_md_stop+0x13a/0x499 This has been there for a while, but is easier to trigger now that mdmon is closely watching sysfs. Cc: <stable@kernel.org> Reported-by: Jacek Danecki <jacek.danecki@intel.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2009-02-18block: fix bad definition of BIO_RW_SYNCJens Axboe
We can't OR shift values, so get rid of BIO_RW_SYNC and use BIO_RW_SYNCIO and BIO_RW_UNPLUG explicitly. This brings back the behaviour from before 213d9417fec62ef4c3675621b9364a667954d4dd. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>