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path: root/drivers/md
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2010-11-24md: Call blk_queue_flush() to establish flush/fua supportDarrick J. Wong
Before 2.6.37, the md layer had a mechanism for catching I/Os with the barrier flag set, and translating the barrier into barriers for all the underlying devices. With 2.6.37, I/O barriers have become plain old flushes, and the md code was updated to reflect this. However, one piece was left out -- the md layer does not tell the block layer that it supports flushes or FUA access at all, which results in md silently dropping flush requests. Since the support already seems there, just add this one piece of bookkeeping. Signed-off-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-11-24md/raid1: really fix recovery looping when single good device fails.NeilBrown
Commit 4044ba58dd15cb01797c4fd034f39ef4a75f7cc3 supposedly fixed a problem where if a raid1 with just one good device gets a read-error during recovery, the recovery would abort and immediately restart in an infinite loop. However it depended on raid1_remove_disk removing the spare device from the array. But that does not happen in this case. So add a test so that in the 'recovery_disabled' case, the device will be removed. This suitable for any kernel since 2.6.29 which is when recovery_disabled was introduced. Cc: stable@kernel.org Reported-by: Sebastian Färber <faerber@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-11-24md: fix return value of rdev_size_change()Justin Maggard
When trying to grow an array by enlarging component devices, rdev_size_store() expects the return value of rdev_size_change() to be in sectors, but the actual value is returned in KBs. This functionality was broken by commit dd8ac336c13fd8afdb082ebacb1cddd5cf727889 so this patch is suitable for any kernel since 2.6.30. Cc: stable@kernel.org Signed-off-by: Justin Maggard <jmaggard10@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-11-10block: read i_size with i_size_read()Mike Snitzer
Convert direct reads of an inode's i_size to using i_size_read(). i_size_{read,write} use a seqcount to protect reads from accessing incomple writes. Concurrent i_size_write()s require mutual exclussion to protect the seqcount that is used by i_size_{read,write}. But i_size_read() callers do not need to use additional locking. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Acked-by: NeilBrown <neilb@suse.de> Acked-by: Lars Ellenberg <lars.ellenberg@linbit.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-29md: tidy up device searches in read_balance.NeilBrown
The code for searching through the device list to read-balance in raid1 is rather clumsy and hard to follow. Try to simplify it a bit. No important functionality change here. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-29md/raid1: fix some typos in comments.NeilBrown
Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-29md/raid1: discard unused variable.NeilBrown
This structure field (flushing_bio_list) is never used, so remove it. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-29md: unplug writes to external bitmaps.NeilBrown
When writing to an 'external' bitmap we don't currently unplug the device before waiting, so we can get a 3msec delay each time; So use REQ_UNPLUG to force and unplug. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: use separate bio pool for each md device.NeilBrown
bio_clone and bio_alloc allocate from a common bio pool. If an md device is stacked with other devices that use this pool, or under something like swap which uses the pool, then the multiple calls on the pool can cause deadlocks. So allocate a local bio pool for each md array and use that rather than the common pool. This pool is used both for regular IO and metadata updates. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: change type of first arg to sync_page_io.NeilBrown
Currently sync_page_io takes a 'bdev'. Every caller passes 'rdev->bdev'. We will soon want another field out of the rdev in sync_page_io, So just pass the rdev instead of the bdev out of it. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md/raid1: perform mem allocation before disabling writes during resync.NeilBrown
Though this mem alloc is GFP_NOIO an so will not deadlock, it seems better to do the allocation before 'raise_barrier' which stops any IO requests while the resync proceeds. raid10 always uses this order, so it is at least consistent to do the same in raid1. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: use bio_kmalloc rather than bio_alloc when failure is acceptable.NeilBrown
bio_alloc can never fail (as it uses a mempool) but an block indefinitely, especially if the caller is holding a reference to a previously allocated bio. So these to places which both handle failure and hold multiple bios should not use bio_alloc, they should use bio_kmalloc. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: Fix possible deadlock with multiple mempool allocations.NeilBrown
It is not safe to allocate from a mempool while holding an item previously allocated from that mempool as that can deadlock when the mempool is close to exhaustion. So don't use a bio list to collect the bios to write to multiple devices in raid1 and raid10. Instead queue each bio as it becomes available so an unplug will activate all previously allocated bios and so a new bio has a chance of being allocated. This means we must set the 'remaining' count to '1' before submitting any requests, then when all are submitted, decrement 'remaining' and possible handle the write completion at that point. Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com> Tested-by: Torsten Kaiser <just.for.lkml@googlemail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: fix and update workqueue usageTejun Heo
Workqueue usage in md has two problems. * Flush can be used during or depended upon by memory reclaim, but md uses the system workqueue for flush_work which may lead to deadlock. * md depends on flush_scheduled_work() to achieve exclusion against completion of removal of previous instances. flush_scheduled_work() may incur unexpected amount of delay and is scheduled to be removed. This patch adds two workqueues to md - md_wq and md_misc_wq. The former is guaranteed to make forward progress under memory pressure and serves flush_work. The latter serves as the flush domain for other works. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: use sector_t in bitmap_get_counterNeilBrown
bitmap_get_counter returns the number of sectors covered by the counter in a pass-by-reference variable. In some cases this can be very large, so make it a sector_t for safety. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: remove md_mutex locking.NeilBrown
lock_kernel calls were recently pushed down into open/release functions. md doesn't need that protection. Then the BKL calls were change to md_mutex. We don't need those either. So remove it all. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-28md: Fix regression with raid1 arrays without persistent metadata.NeilBrown
A RAID1 which has no persistent metadata, whether internal or external, will hang on the first write. This is caused by commit 070dc6dd7103b6b3f7e4d46e754354a5c15f366e In that case, MD_CHANGE_PENDING never gets cleared. So during md_update_sb, is neither persistent or external, clear MD_CHANGE_PENDING. This is suitable for 2.6.36-stable. Signed-off-by: NeilBrown <neilb@suse.de> Cc: stable@kernel.org
2010-10-26workqueues: s/ON_STACK/ONSTACK/Andrew Morton
Silly though it is, completions and wait_queue_heads use foo_ONSTACK (COMPLETION_INITIALIZER_ONSTACK, DECLARE_COMPLETION_ONSTACK, __WAIT_QUEUE_HEAD_INIT_ONSTACK and DECLARE_WAIT_QUEUE_HEAD_ONSTACK) so I guess workqueues should do the same thing. s/INIT_WORK_ON_STACK/INIT_WORK_ONSTACK/ s/INIT_DELAYED_WORK_ON_STACK/INIT_DELAYED_WORK_ONSTACK/ Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-23Merge branch 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.37/barrier' of git://git.kernel.dk/linux-2.6-block: (46 commits) xen-blkfront: disable barrier/flush write support Added blk-lib.c and blk-barrier.c was renamed to blk-flush.c block: remove BLKDEV_IFL_WAIT aic7xxx_old: removed unused 'req' variable block: remove the BH_Eopnotsupp flag block: remove the BLKDEV_IFL_BARRIER flag block: remove the WRITE_BARRIER flag swap: do not send discards as barriers fat: do not send discards as barriers ext4: do not send discards as barriers jbd2: replace barriers with explicit flush / FUA usage jbd2: Modify ASYNC_COMMIT code to not rely on queue draining on barrier jbd: replace barriers with explicit flush / FUA usage nilfs2: replace barriers with explicit flush / FUA usage reiserfs: replace barriers with explicit flush / FUA usage gfs2: replace barriers with explicit flush / FUA usage btrfs: replace barriers with explicit flush / FUA usage xfs: replace barriers with explicit flush / FUA usage block: pass gfp_mask and flags to sb_issue_discard dm: convey that all flushes are processed as empty ...
2010-10-23Merge branch 'for-2.6.37/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* 'for-2.6.37/core' of git://git.kernel.dk/linux-2.6-block: (39 commits) cfq-iosched: Fix a gcc 4.5 warning and put some comments block: Turn bvec_k{un,}map_irq() into static inline functions block: fix accounting bug on cross partition merges block: Make the integrity mapped property a bio flag block: Fix double free in blk_integrity_unregister block: Ensure physical block size is unsigned int blkio-throttle: Fix possible multiplication overflow in iops calculations blkio-throttle: limit max iops value to UINT_MAX blkio-throttle: There is no need to convert jiffies to milli seconds blkio-throttle: Fix link failure failure on i386 blkio: Recalculate the throttled bio dispatch time upon throttle limit change blkio: Add root group to td->tg_list blkio: deletion of a cgroup was causes oops blkio: Do not export throttle files if CONFIG_BLK_DEV_THROTTLING=n block: set the bounce_pfn to the actual DMA limit rather than to max memory block: revert bad fix for memory hotplug causing bounces Fix compile error in blk-exec.c for !CONFIG_DETECT_HUNG_TASK block: set the bounce_pfn to the actual DMA limit rather than to max memory block: Prevent hang_check firing during long I/O cfq: improve fsync performance for small files ... Fix up trivial conflicts due to __rcu sparse annotation in include/linux/genhd.h
2010-10-22Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: vfs: make no_llseek the default vfs: don't use BKL in default_llseek llseek: automatically add .llseek fop libfs: use generic_file_llseek for simple_attr mac80211: disallow seeks in minstrel debug code lirc: make chardev nonseekable viotape: use noop_llseek raw: use explicit llseek file operations ibmasmfs: use generic_file_llseek spufs: use llseek in all file operations arm/omap: use generic_file_llseek in iommu_debug lkdtm: use generic_file_llseek in debugfs net/wireless: use generic_file_llseek in debugfs drm: use noop_llseek
2010-10-22Merge branch 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bklLinus Torvalds
* 'trivial' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl: block: autoconvert trivial BKL users to private mutex drivers: autoconvert trivial BKL users to private mutex ipmi: autoconvert trivial BKL users to private mutex mac: autoconvert trivial BKL users to private mutex mtd: autoconvert trivial BKL users to private mutex scsi: autoconvert trivial BKL users to private mutex Fix up trivial conflicts (due to addition of private mutex right next to deletion of a version string) in drivers/char/pcmcia/cm40[04]0_cs.c
2010-10-19Merge branch 'v2.6.36-rc8' into for-2.6.37/barrierJens Axboe
Conflicts: block/blk-core.c drivers/block/loop.c mm/swapfile.c Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-15llseek: automatically add .llseek fopArnd Bergmann
All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-10-07md: check return code of read_sb_pageVasiliy Kulikov
Function read_sb_page may return ERR_PTR(...). Check for it. Signed-off-by: Vasiliy Kulikov <segooon@gmail.com> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-07md/raid1: minor bio initialisation improvements.NeilBrown
When performing a resync we pre-allocate some bios and repeatedly use them. This requires us to re-initialise them each time. One field (bi_comp_cpu) and some flags weren't being initiaised reliably. Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-07md/raid1: avoid overflow in raid1 resync when bitmap is in use.NeilBrown
bitmap_start_sync returns - via a pass-by-reference variable - the number of sectors before we need to check with the bitmap again. Since commit ef4256733506f245 this number can be substantially larger, 2^27 is a common value. Unfortunately it is an 'int' and so when raid1.c:sync_request shifts it 9 places to the left it becomes 0. This results in a zero-length read which the scsi layer justifiably complains about. This patch just removes the shift so the common case becomes safe with a trivially-correct patch. In the next merge window we will convert this 'int' to a 'sector_t' Reported-by: "George Spelvin" <linux@horizon.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-10-05block: autoconvert trivial BKL users to private mutexArnd Bergmann
The block device drivers have all gained new lock_kernel calls from a recent pushdown, and some of the drivers were already using the BKL before. This turns the BKL into a set of per-driver mutexes. Still need to check whether this is safe to do. file=$1 name=$2 if grep -q lock_kernel ${file} ; then if grep -q 'include.*linux.mutex.h' ${file} ; then sed -i '/include.*<linux\/smp_lock.h>/d' ${file} else sed -i 's/include.*<linux\/smp_lock.h>.*$/include <linux\/mutex.h>/g' ${file} fi sed -i ${file} \ -e "/^#include.*linux.mutex.h/,$ { 1,/^\(static\|int\|long\)/ { /^\(static\|int\|long\)/istatic DEFINE_MUTEX(${name}_mutex); } }" \ -e "s/\(un\)*lock_kernel\>[ ]*()/mutex_\1lock(\&${name}_mutex)/g" \ -e '/[ ]*cycle_kernel_lock();/d' else sed -i -e '/include.*\<smp_lock.h\>/d' ${file} \ -e '/cycle_kernel_lock()/d' fi Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2010-09-17md: fix v1.x metadata update when a disk is missing.NeilBrown
If an array with 1.x metadata is assembled with the last disk missing, md doesn't properly record the fact that the disk was missing. This is unlikely to cause a real problem as the event count will be different to the count on the missing disk so it won't be included in the array. However it could still cause confusion. So make sure we clear all the relevant slots, not just the early ones. Signed-off-by: NeilBrown <neilb@suse.de>
2010-09-17md: call md_update_sb even for 'external' metadata arrays.NeilBrown
Now that we depend on md_update_sb to clear variable bits in mddev->flags (rather than trying not to set them) it is important to always call md_update_sb when appropriate. md_check_recovery has this job but explicitly avoids it for ->external metadata arrays. This is not longer appropraite, or needed. However we do want to avoid taking the mddev lock if only MD_CHANGE_PENDING is set as that is not cleared by md_update_sb for external-metadata arrays. Reported-by: "Kwolek, Adam" <adam.kwolek@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-09-10Consolidate min_not_zeroMartin K. Petersen
We have several users of min_not_zero, each of them using their own definition. Move the define to kernel.h. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@carl.home.kernel.dk>
2010-09-10dm: convey that all flushes are processed as emptyMike Snitzer
Rename __clone_and_map_flush to __clone_and_map_empty_flush for added clarity. Simplify logic associated with REQ_FLUSH conditionals. Introduce a BUG_ON() and add a few more helpful comments to the code so that it is clear that all flushes are empty. Cleanup __split_and_process_bio() so that an empty flush isn't processed by a 'sector_count' focused while loop. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10dm: fix locking context in queue_io()Kiyoshi Ueda
Now queue_io() is called from dec_pending(), which may be called with interrupts disabled, so queue_io() must not enable interrupts unconditionally and must save/restore the current interrupts status. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10dm: relax ordering of bio-based flush implementationTejun Heo
Unlike REQ_HARDBARRIER, REQ_FLUSH/FUA doesn't mandate any ordering against other bio's. This patch relaxes ordering around flushes. * A flush bio is no longer deferred to workqueue directly. It's processed like other bio's but __split_and_process_bio() uses md->flush_bio as the clone source. md->flush_bio is initialized to empty flush during md initialization and shared for all flushes. * As a flush bio now travels through the same execution path as other bio's, there's no need for dedicated error handling path either. It can use the same error handling path in dec_pending(). Dedicated error handling removed along with md->flush_error. * When dec_pending() detects that a flush has completed, it checks whether the original bio has data. If so, the bio is queued to the deferred list w/ REQ_FLUSH cleared; otherwise, it's completed. * As flush sequencing is handled in the usual issue/completion path, dm_wq_work() no longer needs to handle flushes differently. Now its only responsibility is re-issuing deferred bio's the same way as _dm_request() would. REQ_FLUSH handling logic including process_flush() is dropped. * There's no reason for queue_io() and dm_wq_work() write lock dm->io_lock. queue_io() now only uses md->deferred_lock and dm_wq_work() read locks dm->io_lock. * bio's no longer need to be queued on the deferred list while a flush is in progress making DMF_QUEUE_IO_TO_THREAD unncessary. Drop it. This avoids stalling the device during flushes and simplifies the implementation. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10dm: implement REQ_FLUSH/FUA support for request-based dmTejun Heo
This patch converts request-based dm to support the new REQ_FLUSH/FUA. The original request-based flush implementation depended on request_queue blocking other requests while a barrier sequence is in progress, which is no longer true for the new REQ_FLUSH/FUA. In general, request-based dm doesn't have infrastructure for cloning one source request to multiple targets, but the original flush implementation had a special mostly independent path which can issue flushes to multiple targets and sequence them. However, the capability isn't currently in use and adds a lot of complexity. Moreoever, it's unlikely to be useful in its current form as it doesn't make sense to be able to send out flushes to multiple targets when write requests can't be. This patch rips out special flush code path and deals handles REQ_FLUSH/FUA requests the same way as other requests. The only special treatment is that REQ_FLUSH requests use the block address 0 when finding target, which is enough for now. * added BUG_ON(!dm_target_is_valid(ti)) in dm_request_fn() as suggested by Mike Snitzer Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Mike Snitzer <snitzer@redhat.com> Tested-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10dm: implement REQ_FLUSH/FUA support for bio-based dmTejun Heo
This patch converts bio-based dm to support REQ_FLUSH/FUA instead of now deprecated REQ_HARDBARRIER. * -EOPNOTSUPP handling logic dropped. * Preflush is handled as before but postflush is dropped and replaced with passing down REQ_FUA to member request_queues. This replaces one array wide cache flush w/ member specific FUA writes. * __split_and_process_bio() now calls __clone_and_map_flush() directly for flushes and guarantees all FLUSH bio's going to targets are zero ` length. * It's now guaranteed that all FLUSH bio's which are passed onto dm targets are zero length. bio_empty_barrier() tests are replaced with REQ_FLUSH tests. * Empty WRITE_BARRIERs are replaced with WRITE_FLUSHes. * Dropped unlikely() around REQ_FLUSH tests. Flushes are not unlikely enough to be marked with unlikely(). * Block layer now filters out REQ_FLUSH/FUA bio's if the request_queue doesn't support cache flushing. Advertise REQ_FLUSH | REQ_FUA capability. * Request based dm isn't converted yet. dm_init_request_based_queue() resets flush support to 0 for now. To avoid disturbing request based dm code, dm->flush_error is added for bio based dm while requested based dm continues to use dm->barrier_error. Lightly tested linear, stripe, raid1, snap and crypt targets. Please proceed with caution as I'm not familiar with the code base. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: dm-devel@redhat.com Cc: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10md: implment REQ_FLUSH/FUA supportTejun Heo
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: Tejun Heo <tj@kernel.org> Reviewed-by: Neil Brown <neilb@suse.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-09-10block: deprecate barrier and replace blk_queue_ordered() with blk_queue_flush()Tejun Heo
Barrier is deemed too heavy and will soon be replaced by FLUSH/FUA requests. Deprecate barrier. All REQ_HARDBARRIERs are failed with -EOPNOTSUPP and blk_queue_ordered() is replaced with simpler blk_queue_flush(). blk_queue_flush() takes combinations of REQ_FLUSH and FUA. If a device has write cache and can flush it, it should set REQ_FLUSH. If the device can handle FUA writes, it should also set REQ_FUA. All blk_queue_ordered() users are converted. * ORDERED_DRAIN is mapped to 0 which is the default value. * ORDERED_DRAIN_FLUSH is mapped to REQ_FLUSH. * ORDERED_DRAIN_FLUSH_FUA is mapped to REQ_FLUSH | REQ_FUA. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Boaz Harrosh <bharrosh@panasas.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Nick Piggin <npiggin@kernel.dk> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Jeremy Fitzhardinge <jeremy@xensource.com> Cc: Chris Wright <chrisw@sous-sol.org> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Cc: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com> Cc: David S. Miller <davem@davemloft.net> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Pierre Ossman <drzeus@drzeus.cx> Cc: Stefan Weinhuber <wein@de.ibm.com> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-08-30md: resolve confusion of MD_CHANGE_CLEANNeilBrown
MD_CHANGE_CLEAN is used for two different purposes and this leads to confusion. One of the purposes is largely mirrored by MD_CHANGE_PENDING which is not used for anything else, so have MD_CHANGE_PENDING take over that purpose fully. The two purposes are: 1/ tell md_update_sb that an update is needed and that it is just a clean/dirty transition. 2/ tell user-space that an transition from clean to dirty is pending (something wants to write), and tell te kernel (by clearin the flag) that the transition is OK. The first purpose remains wit MD_CHANGE_CLEAN, the second is moved fully to MD_CHANGE_PENDING. This means that various places which conditionally set or cleared MD_CHANGE_CLEAN no longer need to be conditional. Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-30md: don't clear MD_CHANGE_CLEAN in md_update_sb() for external arraysDan Williams
If this bit is cleared in md_update_sb() the kernel will allow writes to the array if userspace triggers md_allow_write(), e.g. through stripe_cache_size, when mdmon is not active. When mdmon is active the array transitions to active-idle bypassing write-pending, setting up a race for mdmon to set the array clean before a write arrives. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-30Move .gitignore from drivers/md to lib/raid6NeilBrown
Another missing bit of the raid6 -> /lib move. Reported-by: Andreas Schwab <schwab@linux-m68k.org> Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-18md raid-1/10 Fix bio_rw bit manipulations againNeilBrown
commit 7b6d91daee5cac6402186ff224c3af39d79f4a0e changed the behaviour of a few variables in raid1 and raid10 from flags to bit-sets, but left them as type 'bool' so they did not work. Change them (back) to unsigned long. (historical note: see 1ef04fefe2241087d9db7e9615c3f11b516e36cf) Signed-off-by: NeilBrown <neilb@suse.de> Reported-by: Jiri Slaby <jslaby@suse.cz> and many others
2010-08-18md: provide appropriate return value for spare_active functions.NeilBrown
md_check_recovery expects ->spare_active to return 'true' if any spares were activated, but none of them do, so the consequent change in 'degraded' is not notified through sysfs. So count the number of spares activated, subtract it from 'degraded' just once, and return it. Reported-by: Adrian Drzewiecki <adriand@vmware.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-18md: Notify sysfs when RAID1/5/10 disk is In_sync.Adrian Drzewiecki
When RAID1 is done syncing disks, it'll update the state of synced rdevs to In_sync. But it neglected to notify sysfs that the attribute changed. So any programs that are waiting for an rdev's state to change will not be woken. (raid5/raid10 added by neilb) Signed-off-by: Adrian Drzewiecki <adriand@vmware.com> Signed-off-by: NeilBrown <neilb@suse.de>
2010-08-18Update recovery_offset even when external metadata is used.NeilBrown
The update of ->recovery_offset in sync_sbs is appropriate even then external metadata is in use. However sync_sbs is only called when native metadata is used. So move that update in to the top of md_update_sb (which is the only caller of sync_sbs) before the test on ->external. This moves the update out of ->write_lock protection, but those fields only need ->reconfig_mutex protection which they still have. Also move the test on ->persistent up to where ->external is set as for metadata update purposes they are the same. Clear MD_CHANGE_DEVS and MD_CHANGE_CLEAN as they can only be confusing if ->external is set or ->persistent isn't. Finally move the update of ->utime down as it is only relevent (like the ->events update) for native metadata. Signed-off-by: NeilBrown <neilb@suse.de> Reported-by: "Kwolek, Adam" <adam.kwolek@intel.com>
2010-08-12dm mpath: support discardMike Snitzer
Enable discard support in the DM multipath target. This discard support depends on a few discard-specific fixes to the block layer's request stacking driver methods. Discard requests are optional so don't allow a failed discard to trigger path failures. If there is a real problem with a given path the barriers associated with the discard (either before or after the discard) will cause path failure. That said, unconditionally passing discard failures up the stack is not ideal. This must be fixed once DM has more information about the nature of the underlying storage failure. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Kiyoshi Ueda <k-ueda@ct.jp.nec.com>
2010-08-12dm stripe: support discardsMikulas Patocka
The DM core will submit a discard bio to the stripe target for each stripe in a striped DM device. The stripe target will determine stripe-specific portions of the supplied bio to be remapped into individual (at most 'num_discard_requests' extents). If a given stripe-specific discard bio doesn't touch a particular stripe the bio will be dropped. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12dm: split discard requests on target boundariesMike Snitzer
Update __clone_and_map_discard to loop across all targets in a DM device's table when it processes a discard bio. If a discard crosses a target boundary it must be split accordingly. Update __issue_target_requests and __issue_target_request to allow a cloned discard bio to have a custom start sector and size. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12dm stripe: optimize sector divisionMikulas Patocka
Optimize sector division: If the number of stripes is a power of two, we can do shift and mask instead of division. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
2010-08-12dm stripe: move sector translation to a functionMikulas Patocka
Move sector to stripe translation into a function. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>