- 10 11月, 2016 1 次提交
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由 NeilBrown 提交于
This is less error prone than using individual #defines. Signed-off-by: NNeilBrown <neilb@suse.com> Signed-off-by: NShaohua Li <shli@fb.com>
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- 12 10月, 2015 1 次提交
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由 Goldwyn Rodrigues 提交于
Suspending the entire device for resync could take too long. Resync in small chunks. cluster's resync window (32M) is maintained in r1conf as cluster_sync_low and cluster_sync_high and processed in raid1's sync_request(). If the current resync is outside the cluster resync window: 1. Set the cluster_sync_low to curr_resync_completed. 2. Check if the sync will fit in the new window, if not issue a wait_barrier() and set cluster_sync_low to sector_nr. 3. Set cluster_sync_high to cluster_sync_low + resync_window. 4. Send a message to all nodes so they may add it in their suspension list. bitmap_cond_end_sync is modified to allow to force a sync inorder to get the curr_resync_completed uptodate with the sector passed. Signed-off-by: NGoldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 01 9月, 2015 1 次提交
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由 NeilBrown 提交于
When a write to one of the legs of a RAID1 fails, the failure is recorded in the metadata of the other leg(s) so that after a restart the data on the failed drive wont be trusted even if that drive seems to be working again (maybe a cable was unplugged). Similarly when we record a bad-block in response to a write failure, we must not let the write complete until the bad-block update is safe. Currently there is no interlock between the write request completing and the metadata update. So it is possible that the write will complete, the app will confirm success in some way, and then the machine will crash before the metadata update completes. This is an extremely small hole for a racy to fit in, but it is theoretically possible and so should be closed. So: - set MD_CHANGE_PENDING when requesting a metadata update for a failed device, so we can know with certainty when it completes - queue requests that experienced an error on a new queue which is only processed after the metadata update completes - call raid_end_bio_io() on bios in that queue when the time comes. Signed-off-by: NNeilBrown <neilb@suse.com>
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- 04 2月, 2015 1 次提交
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由 NeilBrown 提交于
There is currently no locking around calls to the 'congested' bdi function. If called at an awkward time while an array is being converted from one level (or personality) to another, there is a tiny chance of running code in an unreferenced module etc. So add a 'congested' function to the md_personality operations structure, and call it with appropriate locking from a central 'mddev_congested'. When the array personality is changing the array will be 'suspended' so no IO is processed. If mddev_congested detects this, it simply reports that the array is congested, which is a safe guess. As mddev_suspend calls synchronize_rcu(), mddev_congested can avoid races by included the whole call inside an rcu_read_lock() region. This require that the congested functions for all subordinate devices can be run under rcu_lock. Fortunately this is the case. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 14 10月, 2014 1 次提交
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由 NeilBrown 提交于
My editor shows much of this is RED. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 19 11月, 2013 2 次提交
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由 majianpeng 提交于
There is an iobarrier in raid1 because of contention between normal IO and resync IO. It suspends all normal IO when resync/recovery happens. However if normal IO is out side the resync window, there is no contention. So this patch changes the barrier mechanism to only block IO that could contend with the resync that is currently happening. We partition the whole space into five parts. |---------|-----------|------------|----------------|-------| start next_resync start_next_window end_window start + RESYNC_WINDOW = next_resync next_resync + NEXT_NORMALIO_DISTANCE = start_next_window start_next_window + NEXT_NORMALIO_DISTANCE = end_window Firstly we introduce some concepts: 1 - RESYNC_WINDOW: For resync, there are 32 resync requests at most at the same time. A sync request is RESYNC_BLOCK_SIZE(64*1024). So the RESYNC_WINDOW is 32 * RESYNC_BLOCK_SIZE, that is 2MB. 2 - NEXT_NORMALIO_DISTANCE: the distance between next_resync and start_next_window. It also indicates the distance between start_next_window and end_window. It is currently 3 * RESYNC_WINDOW_SIZE but could be tuned if this turned out not to be optimal. 3 - next_resync: the next sector at which we will do sync IO. 4 - start: a position which is at most RESYNC_WINDOW before next_resync. 5 - start_next_window: a position which is NEXT_NORMALIO_DISTANCE beyond next_resync. Normal-io after this position doesn't need to wait for resync-io to complete. 6 - end_window: a position which is 2 * NEXT_NORMALIO_DISTANCE beyond next_resync. This also doesn't need to wait, but is counted differently. 7 - current_window_requests: the count of normalIO between start_next_window and end_window. 8 - next_window_requests: the count of normalIO after end_window. NormalIO will be partitioned into four types: NormIO1: the end sector of bio is smaller or equal the start NormIO2: the start sector of bio larger or equal to end_window NormIO3: the start sector of bio larger or equal to start_next_window. NormIO4: the location between start_next_window and end_window |--------|-----------|--------------------|----------------|-------------| | start | next_resync | start_next_window | end_window | NormIO1 NormIO4 NormIO4 NormIO3 NormIO2 For NormIO1, we don't need any io barrier. For NormIO4, we used a similar approach to the original iobarrier mechanism. The normalIO and resyncIO must be kept separate. For NormIO2/3, we add two fields to struct r1conf: "current_window_requests" and "next_window_requests". They indicate the count of active requests in the two window. For these, we don't wait for resync io to complete. For resync action, if there are NormIO4s, we must wait for it. If not, we can proceed. But if resync action reaches start_next_window and current_window_requests > 0 (that is there are NormIO3s), we must wait until the current_window_requests becomes zero. When current_window_requests becomes zero, start_next_window also moves forward. Then current_window_requests will replaced by next_window_requests. There is a problem which when and how to change from NormIO2 to NormIO3. Only then can sync action progress. We add a field in struct r1conf "start_next_window". A: if start_next_window == MaxSector, it means there are no NormIO2/3. So start_next_window = next_resync + NEXT_NORMALIO_DISTANCE B: if current_window_requests == 0 && next_window_requests != 0, it means start_next_window move to end_window There is another problem which how to differentiate between old NormIO2(now it is NormIO3) and NormIO2. For example, there are many bios which are NormIO2 and a bio which is NormIO3. NormIO3 firstly completed, so the bios of NormIO2 became NormIO3. We add a field in struct r1bio "start_next_window". This is used to record the position conf->start_next_window when the call to wait_barrier() is made in make_request(). In allow_barrier(), we check the conf->start_next_window. If r1bio->stat_next_window == conf->start_next_window, it means there is no transition between NormIO2 and NormIO3. If r1bio->start_next_window != conf->start_next_window, it mean there was a transition between NormIO2 and NormIO3. There can only have been one transition. So it only means the bio is old NormIO2. For one bio, there may be many r1bio's. So we make sure all the r1bio->start_next_window are the same value. If we met blocked_dev in make_request(), it must call allow_barrier and wait_barrier. So the former and the later value of conf->start_next_window will be change. If there are many r1bio's with differnet start_next_window, for the relevant bio, it depend on the last value of r1bio. It will cause error. To avoid this, we must wait for previous r1bios to complete. Signed-off-by: NJianpeng Ma <majianpeng@gmail.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 majianpeng 提交于
Because the following patch will rewrite the content between normal IO and resync IO. So we used a parameter to indicate whether raid is in freeze array. Signed-off-by: NJianpeng Ma <majianpeng@gmail.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 31 7月, 2012 4 次提交
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由 Shaohua Li 提交于
For SSD, if request size exceeds specific value (optimal io size), request size isn't important for bandwidth. In such condition, if making request size bigger will cause some disks idle, the total throughput will actually drop. A good example is doing a readahead in a two-disk raid1 setup. So when should we split big requests? We absolutly don't want to split big request to very small requests. Even in SSD, big request transfer is more efficient. This patch only considers request with size above optimal io size. If all disks are busy, is it worth doing a split? Say optimal io size is 16k, two requests 32k and two disks. We can let each disk run one 32k request, or split the requests to 4 16k requests and each disk runs two. It's hard to say which case is better, depending on hardware. So only consider case where there are idle disks. For readahead, split is always better in this case. And in my test, below patch can improve > 30% thoughput. Hmm, not 100%, because disk isn't 100% busy. Such case can happen not just in readahead, for example, in directio. But I suppose directio usually will have bigger IO depth and make all disks busy, so I ignored it. Note: if the raid uses any hard disk, we don't prevent merging. That will make performace worse. Signed-off-by: NShaohua Li <shli@fusionio.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Shaohua Li 提交于
Currently the sequential read detection is global wide. It's natural to make it per disk based, which can improve the detection for concurrent multiple sequential reads. And next patch will make SSD read balance not use distance based algorithm, where this change help detect truly sequential read for SSD. Signed-off-by: NShaohua Li <shli@fusionio.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Jonathan Brassow 提交于
MD RAID1/RAID10: Move some macros from .h file to .c file There are three macros (IO_BLOCKED,IO_MADE_GOOD,BIO_SPECIAL) which are defined in both raid1.h and raid10.h. They are only used in there respective .c files. However, if we wish to make RAID10 accessible to the device-mapper RAID target (dm-raid.c), then we need to move these macros into the .c files where they are used so that they do not conflict with each other. The macros from the two files are identical and could be moved into md.h, but I chose to leave the duplication and have them remain in the personality files. Signed-off-by: NJonathan Brassow <jbrassow@redhat.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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由 Jonathan Brassow 提交于
MD RAID1: Rename the structure 'mirror_info' to 'raid1_info' The same structure name ('mirror_info') is used by raid10. Each of these structures are defined in there respective header files. If dm-raid is to support both RAID1 and RAID10, the header files will be included and the structure names must not collide. While only one of these structure names needs to change, this patch adds consistency to the naming of the structure. Signed-off-by: NJonathan Brassow <jbrassow@redhat.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 23 12月, 2011 1 次提交
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由 NeilBrown 提交于
In RAID1, a replacement is much like a normal device, so we just double the size of the relevant arrays and look at all possible devices for reads and writes. This means that the array looks like it is now double the size in some way - we need to be careful about that. In particular, we checking if the array is still degraded while creating a recovery request we need to only consider the first 'half' - i.e. the real (non-replacement) devices. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 11 10月, 2011 7 次提交
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由 NeilBrown 提交于
RAID1 and RAID10 handle write requests by queuing them for handling by a separate thread. This is because when a write-intent-bitmap is active we might need to update the bitmap first, so it is good to queue a lot of writes, then do one big bitmap update for them all. However writeback request devices to appear to be congested after a while so it can make some guesstimate of throughput. The infinite queue defeats that (note that RAID5 has already has a finite queue so it doesn't suffer from this problem). So impose a limit on the number of pending write requests. By default it is 1024 which seems to be generally suitable. Make it configurable via module option just in case someone finds a regression. Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
Having mddev_t and 'struct mddev_s' is ugly and not preferred Signed-off-by: NNeilBrown <neilb@suse.de>
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由 NeilBrown 提交于
The typedefs are just annoying. 'mdk' probably refers to 'md_k.h' which used to be an include file that defined this thing. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 07 10月, 2011 1 次提交
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由 NeilBrown 提交于
There wasn't much and it is inconsistent. Also rearrange fields to keep related fields together. Reported-by: NAapo Laine <aapo.laine@shiftmail.org> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 28 7月, 2011 4 次提交
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由 NeilBrown 提交于
When we get a write error (in the data area, not in metadata), update the badblock log rather than failing the whole device. As the write may well be many blocks, we trying writing each block individually and only log the ones which fail. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NNamhyung Kim <namhyung@gmail.com>
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由 NeilBrown 提交于
When performing write-behind we allocate pages to store the data during write. Previously we just keep a list of pages. Now we keep a list of bi_vec which includes offset and size. This means that the r1bio has complete information to create a new bio which will be needed for retrying after write errors. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NNamhyung Kim <namhyung@gmail.com>
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由 NeilBrown 提交于
If we succeed in writing to a block that was recorded as being bad, we clear the bad-block record. This requires some delayed handling as the bad-block-list update has to happen in process-context. Signed-off-by: NNeilBrown <neilb@suse.de> Reviewed-by: NNamhyung Kim <namhyung@gmail.com>
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由 NeilBrown 提交于
Now that we have a bad block list, we should not read from those blocks. There are several main parts to this: 1/ read_balance needs to check for bad blocks, and return not only the chosen device, but also how many good blocks are available there. 2/ fix_read_error needs to avoid trying to read from bad blocks. 3/ read submission must be ready to issue multiple reads to different devices as different bad blocks on different devices could mean that a single large read cannot be served by any one device, but can still be served by the array. This requires keeping count of the number of outstanding requests per bio. This count is stored in 'bi_phys_segments' 4/ retrying a read needs to also be ready to submit a smaller read and queue another request for the rest. This does not yet handle bad blocks when reading to perform resync, recovery, or check. 'md_trim_bio' will also be used for RAID10, so put it in md.c and export it. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 27 7月, 2011 1 次提交
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由 NeilBrown 提交于
If we hit a read error while recovering a mirror, we want to abort the recovery without necessarily failing the disk - as having a disk this a read error is better than not having an array at all. Currently this is managed with a per-array flag "recovery_disabled" and is only implemented for RAID1. For RAID10 we will need finer grained control as we might want to disable recovery for individual devices separately. So push more of the decision making into the personality. 'recovery_disabled' is now a 'cookie' which is copied when the personality want to disable recovery and is changed when a device is added to the array as this is used as a trigger to 'try recovery again'. This will allow RAID10 to get the control that it needs. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 08 6月, 2011 1 次提交
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由 Jonathan Brassow 提交于
MD RAID1: Changes to allow RAID1 to be used by device-mapper (dm-raid.c) Added the necessary congestion function and conditionalize calls requiring an array 'queue' or 'gendisk'. Signed-off-by: NJonathan Brassow <jbrassow@redhat.com> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 11 5月, 2011 1 次提交
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由 NeilBrown 提交于
The current handling and freeing of these pages is a bit fragile. We only keep the list of allocated pages in each bio, so we need to still have a valid bio when freeing the pages, which is a bit clumsy. So simply store the allocated page list in the r1_bio so it can easily be found and freed when we are finished with the r1_bio. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 29 10月, 2010 1 次提交
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由 NeilBrown 提交于
This structure field (flushing_bio_list) is never used, so remove it. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 10 9月, 2010 1 次提交
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由 Tejun Heo 提交于
This patch converts md to support REQ_FLUSH/FUA instead of now deprecated REQ_HARDBARRIER. In the core part (md.c), the following changes are notable. * Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA don't interfere with processing of other requests and thus there is no reason to mark the queue congested while FLUSH/FUA is in progress. * REQ_FLUSH/FUA failures are final and its users don't need retry logic. Retry logic is removed. * Preflush needs to be issued to all member devices but FUA writes can be handled the same way as other writes - their processing can be deferred to request_queue of member devices. md_barrier_request() is renamed to md_flush_request() and simplified accordingly. For linear, raid0 and multipath, the core changes are enough. raid1, 5 and 10 need the following conversions. * raid1: Handling of FLUSH/FUA bio's can simply be deferred to request_queues of member devices. Barrier related logic removed. * raid5: Queue draining logic dropped. FUA bit is propagated through biodrain and stripe resconstruction such that all the updated parts of the stripe are written out with FUA writes if any of the dirtying writes was FUA. preread_active_stripes handling in make_request() is updated as suggested by Neil Brown. * raid10: FUA bit needs to be propagated to write clones. linear, raid0, 1, 5 and 10 tested. Signed-off-by: NTejun Heo <tj@kernel.org> Reviewed-by: NNeil Brown <neilb@suse.de> Signed-off-by: NJens Axboe <jaxboe@fusionio.com>
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- 14 12月, 2009 1 次提交
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由 NeilBrown 提交于
A 2-device raid5 array can now be converted to raid1. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 16 6月, 2009 1 次提交
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由 NeilBrown 提交于
Having a macro just to cast a void* isn't really helpful. I would must rather see that we are simply de-referencing ->private, than have to know what the macro does. So open code the macro everywhere and remove the pointless cast. Signed-off-by: NNeilBrown <neilb@suse.de>
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- 31 3月, 2009 2 次提交
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由 NeilBrown 提交于
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: NNeilBrown <neilb@suse.de>
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由 Christoph Hellwig 提交于
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: NChristoph Hellwig <hch@lst.de> Signed-off-by: NNeilBrown <neilb@suse.de>
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- 03 10月, 2006 1 次提交
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由 NeilBrown 提交于
It is equivalent to conf->raid_disks - conf->mddev->degraded. Signed-off-by: NNeil Brown <neilb@suse.de> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 23 3月, 2006 1 次提交
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由 NeilBrown 提交于
Both R1BIO_Barrier and R1BIO_Returned are 4 !!!! This means that barrier requests don't get returned (i.e. b_endio called) because it looks like they already have been. Signed-off-by: NNeil Brown <neilb@suse.de> Cc: <stable@kernel.org> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 07 1月, 2006 3 次提交
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由 NeilBrown 提交于
Signed-off-by: NNeil Brown <neilb@suse.de> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 NeilBrown 提交于
On a read-error we suspend the array, then synchronously read the block from other arrays until we find one where we can read it. Then we try writing the good data back everywhere and make sure it works. If any write or subsequent read fails, only then do we fail the device out of the array. To be able to suspend the array, we need to also keep track of how many requests are queued for handling by raid1d. Signed-off-by: NNeil Brown <neilb@suse.de> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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由 NeilBrown 提交于
raid1 needs to put up a barrier to new requests while it does resync or other background recovery. The code for this is currently open-coded, slighty obscure by its use of two waitqueues, and not documented. This patch gathers all the related code into 4 functions, and includes a comment which (hopefully) explains what is happening. Signed-off-by: NNeil Brown <neilb@suse.de> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 09 11月, 2005 1 次提交
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由 NeilBrown 提交于
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: NNeil Brown <neilb@cse.unsw.edu.au> Signed-off-by: NNeil Brown <neilb@suse.de> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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- 10 9月, 2005 1 次提交
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由 NeilBrown 提交于
If a device is flagged 'WriteMostly' and the array has a bitmap, and the bitmap superblock indicates that write_behind is allowed, then write_behind is enabled for WriteMostly devices. Write requests will be acknowledges as complete to the caller (via b_end_io) when all non-WriteMostly devices have completed the write, but will not be cleared from the bitmap until all devices complete. This requires memory allocation to make a local copy of the data being written. If there is insufficient memory, then we fall-back on normal write semantics. Signed-Off-By: NPaul Clements <paul.clements@steeleye.com> Signed-off-by: NNeil Brown <neilb@cse.unsw.edu.au> Signed-off-by: NAndrew Morton <akpm@osdl.org> Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
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