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path: root/drivers/md/md.c
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2015-10-02md: clear CHANGE_PENDING in readonly arrayShaohua Li
If faulty disks of an array are more than allowed degraded number, the array enters error handling. It will be marked as read-only with MD_CHANGE_PENDING/RECOVERY_NEEDED set. But currently recovery doesn't clear CHANGE_PENDING bit for read-only array. If MD_CHANGE_PENDING is set for a raid5 array, all returned IO will be hold on a list till the bit is clear. But recovery nevery clears this bit, the IO is always in pending state and nevery finish. This has bad effects like upper layer can't get an IO error and the array can't be stopped. Fixes: c3cce6cda162 ("md/raid5: ensure device failure recorded before write request returns.") Signed-off-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-10-02md: wait for pending superblock updates before switching to read-onlyNeilBrown
If a superblock update is pending, wait for it to complete before letting md_set_readonly() switch to readonly. Otherwise we might lose important information about a device having failed. For external arrays, waiting for superblock updates can wait on user-space, so in that case, just return an error. Reported-and-tested-by: Shaohua Li <shli@fb.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-09-05Merge linux-block/for-4.3/core into md/for-linuxNeilBrown
There were a few conflicts that are fairly easy to resolve. Signed-off-by: NeilBrown <neilb@suse.com>
2015-09-02Merge branch 'for-4.3/core' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block updates from Jens Axboe: "This first core part of the block IO changes contains: - Cleanup of the bio IO error signaling from Christoph. We used to rely on the uptodate bit and passing around of an error, now we store the error in the bio itself. - Improvement of the above from myself, by shrinking the bio size down again to fit in two cachelines on x86-64. - Revert of the max_hw_sectors cap removal from a revision again, from Jeff Moyer. This caused performance regressions in various tests. Reinstate the limit, bump it to a more reasonable size instead. - Make /sys/block/<dev>/queue/discard_max_bytes writeable, by me. Most devices have huge trim limits, which can cause nasty latencies when deleting files. Enable the admin to configure the size down. We will look into having a more sane default instead of UINT_MAX sectors. - Improvement of the SGP gaps logic from Keith Busch. - Enable the block core to handle arbitrarily sized bios, which enables a nice simplification of bio_add_page() (which is an IO hot path). From Kent. - Improvements to the partition io stats accounting, making it faster. From Ming Lei. - Also from Ming Lei, a basic fixup for overflow of the sysfs pending file in blk-mq, as well as a fix for a blk-mq timeout race condition. - Ming Lin has been carrying Kents above mentioned patches forward for a while, and testing them. Ming also did a few fixes around that. - Sasha Levin found and fixed a use-after-free problem introduced by the bio->bi_error changes from Christoph. - Small blk cgroup cleanup from Viresh Kumar" * 'for-4.3/core' of git://git.kernel.dk/linux-block: (26 commits) blk: Fix bio_io_vec index when checking bvec gaps block: Replace SG_GAPS with new queue limits mask block: bump BLK_DEF_MAX_SECTORS to 2560 Revert "block: remove artifical max_hw_sectors cap" blk-mq: fix race between timeout and freeing request blk-mq: fix buffer overflow when reading sysfs file of 'pending' Documentation: update notes in biovecs about arbitrarily sized bios block: remove bio_get_nr_vecs() fs: use helper bio_add_page() instead of open coding on bi_io_vec block: kill merge_bvec_fn() completely md/raid5: get rid of bio_fits_rdev() md/raid5: split bio for chunk_aligned_read block: remove split code in blkdev_issue_{discard,write_same} btrfs: remove bio splitting and merge_bvec_fn() calls bcache: remove driver private bio splitting code block: simplify bio_add_page() block: make generic_make_request handle arbitrarily sized bios blk-cgroup: Drop unlikely before IS_ERR(_OR_NULL) block: don't access bio->bi_error after bio_put() block: shrink struct bio down to 2 cache lines again ...
2015-08-31md/raid1: ensure device failure recorded before write request returns.NeilBrown
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: NeilBrown <neilb@suse.com>
2015-08-31md: extend spinlock protection in register_md_cluster_operationsNeilBrown
This code looks racy. The only possible race is if two modules try to register at the same time and that won't happen. But make the code look safe anyway. Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31md-cluster: transfer the resync ownership to another nodeGuoqing Jiang
When node A stops an array while the array is doing a resync, we need to let another node B take over the resync task. To achieve the goal, we need the A send an explicit BITMAP_NEEDS_SYNC message to the cluster. And the node B which received that message will invoke __recover_slot to do resync. Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31md: setup safemode_timer before it's being usedSasha Levin
We used to set up the safemode_timer timer in md_run. If md_run would fail before the timer was set up we'd end up trying to modify a timer that doesn't have a callback function when we access safe_delay_store, which would trigger a BUG. neilb: delete init_timer() call as setup_timer() does that. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31md: sync sync_completed has correct value as recovery finishes.NeilBrown
There can be a small window between the moment that recovery actually writes the last block and the time when various sysfs and /proc/mdstat attributes report that it has finished. During this time, 'sync_completed' can have the wrong value. This can confuse monitoring software. So: - don't set curr_resync_completed beyond the end of the devices, - set it correctly when resync/recovery has completed. Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31md: be careful when testing resync_max against curr_resync_completed.NeilBrown
While it generally shouldn't happen, it is not impossible for curr_resync_completed to exceed resync_max. This can particularly happen when reshaping RAID5 - the current status isn't copied to curr_resync_completed promptly, so when it is, it can exceed resync_max. This happens when the reshape is 'frozen', resync_max is set low, and reshape is re-enabled. Taking a difference between two unsigned numbers is always dangerous anyway, so add a test to behave correctly if curr_resync_completed > resync_max Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31md: set MD_RECOVERY_RECOVER when starting a degraded array.NeilBrown
This ensures that 'sync_action' will show 'recover' immediately the array is started. If there is no spare the status will change to 'idle' once that is detected. Clear MD_RECOVERY_RECOVER for a read-only array to ensure this change happens. This allows scripts which monitor status not to get confused - particularly my test scripts. Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31md: close some races between setting and checking sync_action.NeilBrown
When checking sync_action in a script, we want to be sure it is as accurate as possible. As resync/reshape etc doesn't always start immediately (a separate thread is scheduled to do it), it is best if 'action_show' checks if MD_RECOVER_NEEDED is set (which it does) and in that case reports what is likely to start soon (which it only sometimes does). So: - report 'reshape' if reshape_position suggests one might start. - set MD_RECOVERY_RECOVER in raid1_reshape(), because that is very likely to happen next. Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-31md: Keep /proc/mdstat reporting recovery until fully DONE.NeilBrown
Currently when a recovery completes, mdstat shows that it has finished before the new device is marked as a full member. Because of this it can appear to a script that the recovery finished but the array isn't in sync. So while MD_RECOVERY_DONE is still set, keep mdstat reporting "recovery". Once md_reap_sync_thread() completes, the spare will be active and then MD_RECOVERY_DONE will be cleared. To ensure this is race-free, set MD_RECOVERY_DONE before clearning curr_resync. Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-13block: kill merge_bvec_fn() completelyKent Overstreet
As generic_make_request() is now able to handle arbitrarily sized bios, it's no longer necessary for each individual block driver to define its own ->merge_bvec_fn() callback. Remove every invocation completely. Cc: Jens Axboe <axboe@kernel.dk> Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Yehuda Sadeh <yehuda@inktank.com> Cc: Sage Weil <sage@inktank.com> Cc: Alex Elder <elder@kernel.org> Cc: ceph-devel@vger.kernel.org Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Neil Brown <neilb@suse.de> Cc: linux-raid@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Acked-by: NeilBrown <neilb@suse.de> (for the 'md' bits) Acked-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: also remove ->merge_bvec_fn() in dm-thin as well as dm-era-target, and resolve merge conflicts] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-13block: make generic_make_request handle arbitrarily sized biosKent Overstreet
The way the block layer is currently written, it goes to great lengths to avoid having to split bios; upper layer code (such as bio_add_page()) checks what the underlying device can handle and tries to always create bios that don't need to be split. But this approach becomes unwieldy and eventually breaks down with stacked devices and devices with dynamic limits, and it adds a lot of complexity. If the block layer could split bios as needed, we could eliminate a lot of complexity elsewhere - particularly in stacked drivers. Code that creates bios can then create whatever size bios are convenient, and more importantly stacked drivers don't have to deal with both their own bio size limitations and the limitations of the (potentially multiple) devices underneath them. In the future this will let us delete merge_bvec_fn and a bunch of other code. We do this by adding calls to blk_queue_split() to the various make_request functions that need it - a few can already handle arbitrary size bios. Note that we add the call _after_ any call to blk_queue_bounce(); this means that blk_queue_split() and blk_recalc_rq_segments() don't need to be concerned with bouncing affecting segment merging. Some make_request_fn() callbacks were simple enough to audit and verify they don't need blk_queue_split() calls. The skipped ones are: * nfhd_make_request (arch/m68k/emu/nfblock.c) * axon_ram_make_request (arch/powerpc/sysdev/axonram.c) * simdisk_make_request (arch/xtensa/platforms/iss/simdisk.c) * brd_make_request (ramdisk - drivers/block/brd.c) * mtip_submit_request (drivers/block/mtip32xx/mtip32xx.c) * loop_make_request * null_queue_bio * bcache's make_request fns Some others are almost certainly safe to remove now, but will be left for future patches. Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Ming Lei <ming.lei@canonical.com> Cc: Neil Brown <neilb@suse.de> Cc: Alasdair Kergon <agk@redhat.com> Cc: Mike Snitzer <snitzer@redhat.com> Cc: dm-devel@redhat.com Cc: Lars Ellenberg <drbd-dev@lists.linbit.com> Cc: drbd-user@lists.linbit.com Cc: Jiri Kosina <jkosina@suse.cz> Cc: Geoff Levand <geoff@infradead.org> Cc: Jim Paris <jim@jtan.com> Cc: Philip Kelleher <pjk1939@linux.vnet.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Nitin Gupta <ngupta@vflare.org> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: Andreas Dilger <andreas.dilger@intel.com> Acked-by: NeilBrown <neilb@suse.de> (for the 'md/md.c' bits) Acked-by: Mike Snitzer <snitzer@redhat.com> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [dpark: skip more mq-based drivers, resolve merge conflicts, etc.] Signed-off-by: Dongsu Park <dpark@posteo.net> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-03md: simplify get_bitmap_file now that "file" is zeroed.Benjamin Randazzo
There is no point assigning '\0' to file->pathname[0] as file is now zeroed out, so remove that branch and simplify the code. [Original patch combined this with the change to use kzalloc. I split the two so that the change to kzalloc is easier to backport. - neilb] Signed-off-by: Benjamin Randazzo <benjamin@randazzo.fr> Signed-off-by: NeilBrown <neilb@suse.com>
2015-08-03md: use kzalloc() when bitmap is disabledBenjamin Randazzo
In drivers/md/md.c get_bitmap_file() uses kmalloc() for creating a mdu_bitmap_file_t called "file". 5769 file = kmalloc(sizeof(*file), GFP_NOIO); 5770 if (!file) 5771 return -ENOMEM; This structure is copied to user space at the end of the function. 5786 if (err == 0 && 5787 copy_to_user(arg, file, sizeof(*file))) 5788 err = -EFAULT But if bitmap is disabled only the first byte of "file" is initialized with zero, so it's possible to read some bytes (up to 4095) of kernel space memory from user space. This is an information leak. 5775 /* bitmap disabled, zero the first byte and copy out */ 5776 if (!mddev->bitmap_info.file) 5777 file->pathname[0] = '\0'; Signed-off-by: Benjamin Randazzo <benjamin@randazzo.fr> Signed-off-by: NeilBrown <neilb@suse.com>
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig
Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-25Merge tag 'md/4.2-fixes' of git://neil.brown.name/mdLinus Torvalds
Pull md fixes from Neil Brown: "Some md fixes for 4.2 Several are tagged for -stable. A few aren't because they are not very, serious or because they are in the 'experimental' cluster code" * tag 'md/4.2-fixes' of git://neil.brown.name/md: md/raid5: clear R5_NeedReplace when no longer needed. Fix read-balancing during node failure md-cluster: fix bitmap sub-offset in bitmap_read_sb md: Return error if request_module fails and returns positive value md: Skip cluster setup in case of error while reading bitmap md/raid1: fix test for 'was read error from last working device'. md: Skip cluster setup for dm-raid md: flush ->event_work before stopping array. md/raid10: always set reshape_safe when initializing reshape_position. md/raid5: avoid races when changing cache size.
2015-07-24md: Return error if request_module fails and returns positive valueGoldwyn Rodrigues
request_module() can return 256 (process exited) in some cases, which is not as specified in the documentation before the request_module() definition. Convert the error to -ENOENT. The positive error number results in bitmap_create() returning a value that is meant to be an error but doesn't look like one, so it is dereferenced as a point and causes a crash. (not needed for stable as this is "experimental" code) Fixes: edb39c9deda8 ("Introduce md_cluster_operations to handle cluster functions") Signed-off-By: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.com>
2015-07-22md: flush ->event_work before stopping array.NeilBrown
The 'event_work' worker used by dm-raid may still be running when the array is stopped. This can result in an oops. So flush the workqueue on which it is run after detaching and before destroying the device. Reported-by: Heinz Mauelshagen <heinzm@redhat.com> Signed-off-by: NeilBrown <neilb@suse.com> Cc: stable@vger.kernel.org (2.6.38+ please delay 2 weeks after -final release) Fixes: 9d09e663d550 ("dm: raid456 basic support")
2015-07-05Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: "Assorted VFS fixes and related cleanups (IMO the most interesting in that part are f_path-related things and Eric's descriptor-related stuff). UFS regression fixes (it got broken last cycle). 9P fixes. fs-cache series, DAX patches, Jan's file_remove_suid() work" [ I'd say this is much more than "fixes and related cleanups". The file_table locking rule change by Eric Dumazet is a rather big and fundamental update even if the patch isn't huge. - Linus ] * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits) 9p: cope with bogus responses from server in p9_client_{read,write} p9_client_write(): avoid double p9_free_req() 9p: forgetting to cancel request on interrupted zero-copy RPC dax: bdev_direct_access() may sleep block: Add support for DAX reads/writes to block devices dax: Use copy_from_iter_nocache dax: Add block size note to documentation fs/file.c: __fget() and dup2() atomicity rules fs/file.c: don't acquire files->file_lock in fd_install() fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation vfs: avoid creation of inode number 0 in get_next_ino namei: make set_root_rcu() return void make simple_positive() public ufs: use dir_pages instead of ufs_dir_pages() pagemap.h: move dir_pages() over there remove the pointless include of lglock.h fs: cleanup slight list_entry abuse xfs: Correctly lock inode when removing suid and file capabilities fs: Call security_ops->inode_killpriv on truncate fs: Provide function telling whether file_remove_privs() will do anything ...
2015-06-29Merge tag 'md/4.2' of git://neil.brown.name/mdLinus Torvalds
Pull md updates from Neil Brown: "A mixed bag - a few bug fixes - some performance improvement that decrease lock contention - some clean-up Nothing major" * tag 'md/4.2' of git://neil.brown.name/md: md: clear Blocked flag on failed devices when array is read-only. md: unlock mddev_lock on an error path. md: clear mddev->private when it has been freed. md: fix a build warning md/raid5: ignore released_stripes check md/raid5: per hash value and exclusive wait_for_stripe md/raid5: split wait_for_stripe and introduce wait_for_quiescent wait: introduce wait_event_exclusive_cmd md: convert to kstrto*() md/raid10: make sync_request_write() call bio_copy_data()
2015-06-26drivers/md/md.c: use strreplace()Rasmus Villemoes
There's no point in starting over when we meet a '/'. This also eliminates a stack variable and a little .text. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: NeilBrown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-06-25md: clear Blocked flag on failed devices when array is read-only.Neil Brown
The Blocked flag indicates that a device has failed but that this fact hasn't been recorded in the metadata yet. Writes to such devices cannot be allowed until the metadata has been updated. On a read-only array, the Blocked flag will never be cleared. This prevents the device being removed from the array. If the metadata is being handled by the kernel (i.e. !mddev->external), then we can be sure that if the array is switch to writable, then a metadata update will happen and will record the failure. So we don't need the flag set. If metadata is externally managed, it is upto the external manager to clear the 'blocked' flag. Reported-by: XiaoNi <xni@redhat.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-06-25md: unlock mddev_lock on an error path.NeilBrown
This error path retuns while still holding the lock - bad. Fixes: 6791875e2e53 ("md: make reconfig_mutex optional for writes to md sysfs files.") Cc: stable@vger.kernel.org (v4.0+) Signed-off-by: NeilBrown <neilb@suse.com>
2015-06-25md: clear mddev->private when it has been freed.NeilBrown
If ->private is set when ->run is called, it is assumed to be a 'config' prepared as part of 'reshape'. So it is important when we free that config, that we also clear ->private. This is not often a problem as the mddev will normally be discarded shortly after the config us freed. However if an 'assemble' races with a final close, the assemble can use the old mddev which has a stale ->private. This leads to any of various sorts of crashes. So clear ->private after calling ->free(). Reported-by: Nate Clark <nate@neworld.us> Cc: stable@vger.kernel.org (v4.0+) Fixes: afa0f557cb15 ("md: rename ->stop to ->free") Signed-off-by: NeilBrown <neilb@suse.com>
2015-06-23vfs: add file_path() helperMiklos Szeredi
Turn d_path(&file->f_path, ...); into file_path(file, ...); Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-17md: fix a build warningFiro Yang
Warning like this: drivers/md/md.c: In function "update_array_info": drivers/md/md.c:6394:26: warning: logical not is only applied to the left hand side of comparison [-Wlogical-not-parentheses] !mddev->persistent != info->not_persistent|| Fix it as Neil Brown said: mddev->persistent != !info->not_persistent || Signed-off-by: Firo Yang <firogm@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-06-17md: convert to kstrto*()Alexey Dobriyan
Convert away from deprecated simple_strto*() functions. Add "fit into sector_t" checks. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-06-12md: make sure MD_RECOVERY_DONE is clear before starting recovery/resyncNeilBrown
MD_RECOVERY_DONE is normally cleared by md_check_recovery after a resync etc finished. However it is possible for raid5_start_reshape to race and start a reshape before MD_RECOVERY_DONE is cleared. This can lean to multiple reshapes running at the same time, which isn't good. To make sure it is cleared before starting a reshape, and also clear it when reaping a thread, just to be safe. Signed-off-by: NeilBrown <neilb@suse.de>
2015-06-12md: Close race when setting 'action' to 'idle'.NeilBrown
Checking ->sync_thread without holding the mddev_lock() isn't really safe, even after flushing the workqueue which ensures md_start_sync() has been run. While this code is waiting for the lock, md_check_recovery could reap the thread itself, and then start another thread (e.g. recovery might finish, then reshape starts). When this thread gets the lock md_start_sync() hasn't run so it doesn't get reaped, but MD_RECOVERY_RUNNING gets cleared. This allows two threads to start which leads to confusion. So don't both if MD_RECOVERY_RUNNING isn't set, but if it is do the flush and the test and the reap all under the mddev_lock to avoid any race with md_check_recovery. Signed-off-by: NeilBrown <neilb@suse.de> Fixes: 6791875e2e53 ("md: make reconfig_mutex optional for writes to md sysfs files.") Cc: stable@vger.kernel.org (v4.0+)
2015-06-12md: don't return 0 from array_state_storeNeilBrown
Returning zero from a 'store' function is bad. The return value should be either len length of the string or an error. So use 'len' if 'err' is zero. Fixes: 6791875e2e53 ("md: make reconfig_mutex optional for writes to md sysfs files.") Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@vger.kernel (v4.0+)
2015-05-29Merge tag 'md/4.1-rc5-fixes' of git://neil.brown.name/mdLinus Torvalds
Pull m,ore md bugfixes gfrom Neil Brown: "Assorted fixes for new RAID5 stripe-batching functionality. Unfortunately this functionality was merged a little prematurely. The necessary testing and code review is now complete (or as complete as it can be) and to code passes a variety of tests and looks quite sensible. Also a fix for some recent locking changes - a race was introduced which causes a reshape request to sometimes fail. No data safety issues" * tag 'md/4.1-rc5-fixes' of git://neil.brown.name/md: md: fix race when unfreezing sync_action md/raid5: break stripe-batches when the array has failed. md/raid5: call break_stripe_batch_list from handle_stripe_clean_event md/raid5: be more selective about distributing flags across batch. md/raid5: add handle_flags arg to break_stripe_batch_list. md/raid5: duplicate some more handle_stripe_clean_event code in break_stripe_batch_list md/raid5: remove condition test from check_break_stripe_batch_list. md/raid5: Ensure a batch member is not handled prematurely. md/raid5: close race between STRIPE_BIT_DELAY and batching. md/raid5: ensure whole batch is delayed for all required bitmap updates.
2015-05-28md: fix race when unfreezing sync_actionNeilBrown
A recent change removed the need for locking around writing to "sync_action" (and various other places), but introduced a subtle race. When e.g. setting 'reshape' on a 'frozen' array, the 'frozen' flag is cleared before 'reshape' is set, so the md thread can get in and start trying recovery - which isn't wanted. So instead of clearing MD_RECOVERY_FROZEN for any command except 'frozen', only clear it when each specific command is parsed. This allows the handling of 'reshape' to clear the bit while a lock is held. Also remove some places where we set MD_RECOVERY_NEEDED, as it is always set on non-error exit of the function. Signed-off-by: NeilBrown <neilb@suse.de> Fixes: 6791875e2e53 ("md: make reconfig_mutex optional for writes to md sysfs files.")
2015-05-09Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "A collection of fixes since the merge window; - fix for a double elevator module release, from Chao Yu. Ancient bug. - the splice() MORE flag fix from Christophe Leroy. - a fix for NVMe, fixing a patch that went in in the merge window. From Keith. - two fixes for blk-mq CPU hotplug handling, from Ming Lei. - bdi vs blockdev lifetime fix from Neil Brown, fixing and oops in md. - two blk-mq fixes from Shaohua, fixing a race on queue stop and a bad merge issue with FUA writes. - division-by-zero fix for writeback from Tejun. - a block bounce page accounting fix, making sure we inc/dec after bouncing so that pre/post IO pages match up. From Wang YanQing" * 'for-linus' of git://git.kernel.dk/linux-block: splice: sendfile() at once fails for big files blk-mq: don't lose requests if a stopped queue restarts blk-mq: fix FUA request hang block: destroy bdi before blockdev is unregistered. block:bounce: fix call inc_|dec_zone_page_state on different pages confuse value of NR_BOUNCE elevator: fix double release of elevator module writeback: use |1 instead of +1 to protect against div by zero blk-mq: fix CPU hotplug handling blk-mq: fix race between timeout and CPU hotplug NVMe: Fix VPD B0 max sectors translation
2015-04-27block: destroy bdi before blockdev is unregistered.NeilBrown
Because of the peculiar way that md devices are created (automatically when the device node is opened), a new device can be created and registered immediately after the blk_unregister_region(disk_devt(disk), disk->minors); call in del_gendisk(). Therefore it is important that all visible artifacts of the previous device are removed before this call. In particular, the 'bdi'. Since: commit c4db59d31e39ea067c32163ac961e9c80198fd37 Author: Christoph Hellwig <hch@lst.de> fs: don't reassign dirty inodes to default_backing_dev_info moved the device_unregister(bdi->dev); call from bdi_unregister() to bdi_destroy() it has been quite easy to lose a race and have a new (e.g.) "md127" be created after the blk_unregister_region() call and before bdi_destroy() is ultimately called by the final 'put_disk', which must come after del_gendisk(). The new device finds that the bdi name is already registered in sysfs and complains > [ 9627.630029] WARNING: CPU: 18 PID: 3330 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x5a/0x70() > [ 9627.630032] sysfs: cannot create duplicate filename '/devices/virtual/bdi/9:127' We can fix this by moving the bdi_destroy() call out of blk_release_queue() (which can happen very late when a refcount reaches zero) and into blk_cleanup_queue() - which happens exactly when the md device driver calls it. Then it is only necessary for md to call blk_cleanup_queue() before del_gendisk(). As loop.c devices are also created on demand by opening the device node, we make the same change there. Fixes: c4db59d31e39ea067c32163ac961e9c80198fd37 Reported-by: Azat Khuzhin <a3at.mail@gmail.com> Cc: Christoph Hellwig <hch@lst.de> Cc: stable@vger.kernel.org (v4.0) Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-21md: allow resync to go faster when there is competing IO.NeilBrown
When md notices non-sync IO happening while it is trying to resync (or reshape or recover) it slows down to the set minimum. The default minimum might have made sense many years ago but the drives have become faster. Changing the default to match the times isn't really a long term solution. This patch changes the code so that instead of waiting until the speed has dropped to the target, it just waits until pending requests have completed. This means that the delay inserted is a function of the speed of the devices. Testing shows that: - for some loads, the resync speed is unchanged. For those loads increasing the minimum doesn't change the speed either. So this is a good result. To increase resync speed under such loads we would probably need to increase the resync window size. - for other loads, resync speed does increase to a reasonable fraction (e.g. 20%) of maximum possible, and throughput of the load only drops a little bit (e.g. 10%) - for other loads, throughput of the non-sync load drops quite a bit more. These seem to be latency-sensitive loads. So it isn't a perfect solution, but it is mostly an improvement. Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-21md: remove 'go_faster' option from ->sync_request()NeilBrown
This option is not well justified and testing suggests that it hardly ever makes any difference. The comment suggests there might be a need to wait for non-resync activity indicated by ->nr_waiting, however raise_barrier() already waits for all of that. So just remove it to simplify reasoning about speed limiting. This allows us to remove a 'FIXME' comment from raid5.c as that never used the flag. Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-21md: don't require sync_min to be a multiple of chunk_size.NeilBrown
There is really no need for sync_min to be a multiple of chunk_size, and values read from here often aren't. That means you cannot read a value and expect to be able to write it back later. So remove the chunk_size check, and round down to a multiple of 4K, to be sure everything works with 4K-sector devices. Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-21Merge branch 'cluster' into for-nextNeilBrown
2015-04-21md-cluster: re-add capabilitiesGoldwyn Rodrigues
When "re-add" is writted to /sys/block/mdXX/md/dev-YYY/state, the clustered md: 1. Sends RE_ADD message with the desc_nr. Nodes receiving the message clear the Faulty bit in their respective rdev->flags. 2. The node initiating re-add, gathers the bitmaps of all nodes and copies them into the local bitmap. It does not clear the bitmap from which it is copying. 3. Initiating node schedules a md recovery to sync the devices. Signed-off-by: Guoqing Jiang <gqjiang@suse.com> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-21md: re-add a failed diskGoldwyn Rodrigues
This adds the capability of re-adding a failed disk by writing "re-add" to /sys/block/mdXX/md/dev-YYY/state. This facilitates adding disks which have encountered a temporary error such as a network disconnection/hiccup in an iSCSI device, or a SAN cable disconnection which has been restored. In such a situation, you do not need to remove and re-add the device. Writing re-add to the failed device's state would add it again to the array and perform the recovery of only the blocks which were written after the device failed. This works for generic md, and is not related to clustering. However, this patch is to ease re-add operations listed above in clustering environments. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-21md-cluster: remove capabilitiesGoldwyn Rodrigues
This adds "remove" capabilities for the clustered environment. When a user initiates removal of a device from the array, a REMOVE message with disk number in the array is sent to all the nodes which kick the respective device in their own array. This facilitates the removal of failed devices. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-21md: Export and rename find_rdev_nr_rcuGoldwyn Rodrigues
This is required by the clustering module (patches to follow) to find the device to remove or re-add. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-21md: Export and rename kick_rdev_from_arrayGoldwyn Rodrigues
This export is required for clustering module in order to co-ordinate remove/readd a rdev from all nodes. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-04-08md: fix md io stats accounting brokenGu Zheng
Simon reported the md io stats accounting issue: " I'm seeing "iostat -x -k 1" print this after a RAID1 rebuild on 4.0-rc5. It's not abnormal other than it's 3-disk, with one being SSD (sdc) and the other two being write-mostly: Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s avgrq-sz avgqu-sz await r_await w_await svctm %util sda 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sdb 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 sdc 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 md0 0.00 0.00 0.00 0.00 0.00 0.00 0.00 345.00 0.00 0.00 0.00 0.00 100.00 md2 0.00 0.00 0.00 0.00 0.00 0.00 0.00 58779.00 0.00 0.00 0.00 0.00 100.00 md1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 12.00 0.00 0.00 0.00 0.00 100.00 " The cause is commit "18c0b223cf9901727ef3b02da6711ac930b4e5d4" uses the generic_start_io_acct to account the disk stats rather than the open code, but it also introduced the increase to .in_flight[rw] which is needless to md. So we re-use the open code here to fix it. Reported-by: Simon Kirby <sim@hostway.ca> Cc: <stable@vger.kernel.org> 3.19 Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-03-20md: Fix stray --cluster-confirm crashGoldwyn Rodrigues
A --cluster-confirm without an --add (by another node) can crash the kernel. Fix it by guarding it using a state. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: NeilBrown <neilb@suse.de>
2015-03-20md: fix problems with freeing private data after ->run failure.NeilBrown
If ->run() fails, it can either free the data structures it allocated, or leave that task to ->free() which will be called on failures. However: md.c calls ->free() even if ->private_data is NULL, which causes problems in some personalities. raid0.c frees the data, but doesn't clear ->private_data, which will become a problem when we fix md.c So better fix both these issues at once. Reported-by: Richard W.M. Jones <rjones@redhat.com> Fixes: 5aa61f427e4979be733e4847b9199ff9cc48a47e URL: https://bugzilla.kernel.org/show_bug.cgi?id=94381 Signed-off-by: NeilBrown <neilb@suse.de>
2015-02-25md: fix error paths from bitmap_create.NeilBrown
Recent change to bitmap_create mishandles errors. In particular a failure doesn't alway cause 'err' to be set. Signed-off-by: NeilBrown <neilb@suse.de>