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* dm table: drop void suspend_targets returnAdrian Bunk2008-04-25
| | | | | | | | | | void returning functions returned the return value of another void returning function... Spotted by sparse. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: unplug queues in threadsMikulas Patocka2008-04-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove an avoidable 3ms delay on some dm-raid1 and kcopyd I/O. It is specified that any submitted bio without BIO_RW_SYNC flag may plug the queue (i.e. block the requests from being dispatched to the physical device). The queue is unplugged when the caller calls blk_unplug() function. Usually, the sequence is that someone calls submit_bh to submit IO on a buffer. The IO plugs the queue and waits (to be possibly joined with other adjacent bios). Then, when the caller calls wait_on_buffer(), it unplugs the queue and submits the IOs to the disk. This was happenning: When doing O_SYNC writes, function fsync_buffers_list() submits a list of bios to dm_raid1, the bios are added to dm_raid1 write queue and kmirrord is woken up. fsync_buffers_list() calls wait_on_buffer(). That unplugs the queue, but there are no bios on the device queue as they are still in the dm_raid1 queue. wait_on_buffer() starts waiting until the IO is finished. kmirrord is scheduled, kmirrord takes bios and submits them to the devices. The submitted bio plugs the harddisk queue but there is no one to unplug it. (The process that called wait_on_buffer() is already sleeping.) So there is a 3ms timeout, after which the queues on the harddisks are unplugged and requests are processed. This 3ms timeout meant that in certain workloads (e.g. O_SYNC, 8kb writes), dm-raid1 is 10 times slower than md raid1. Every time we submit something asynchronously via dm_io, we must unplug the queue actually to send the request to the device. This patch adds an unplug call to kmirrord - while processing requests, it keeps the queue plugged (so that adjacent bios can be merged); when it finishes processing all the bios, it unplugs the queue to submit the bios. It also fixes kcopyd which has the same potential problem. All kcopyd requests are submitted with BIO_RW_SYNC. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Jens Axboe <jens.axboe@oracle.com>
* dm raid1: use timerMikulas Patocka2008-04-25
| | | | | | | | | | | | This patch replaces the schedule() in the main kmirrord thread with a timer. The schedule() could introduce an unwanted delay when work is ready to be processed. The code instead calls wake() when there's work to be done immediately, and delayed_wake() after a failure to give a short delay before retrying. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: move include filesAlasdair G Kergon2008-04-25
| | | | | | Publish the dm-io, dm-log and dm-kcopyd headers in include/linux. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm kcopyd: renameAlasdair G Kergon2008-04-25
| | | | | | Rename kcopyd.[ch] to dm-kcopyd.[ch]. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm: expose macrosAlasdair G Kergon2008-04-25
| | | | | | Make dm.h macros and inlines available in include/linux/device-mapper.h Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm kcopyd: remove redundant client countingMikulas Patocka2008-04-25
| | | | | | | | | | | | Remove client counting code that is no longer needed. Initialization and destruction is made globally from dm_init and dm_exit and is not based on client counts. Initialization allocates only one empty slab cache, so there is no negative impact from performing the initialization always, regardless of whether some client uses kcopyd or not. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm kcopyd: private mempoolMikulas Patocka2008-04-25
| | | | | | | | Change the global mempool in kcopyd into a per-device mempool to avoid deadlock possibilities. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm kcopyd: per deviceMikulas Patocka2008-04-25
| | | | | | | | Make one kcopyd thread per device. The original shared kcopyd could deadlock. Configuration:
* dm log: make module use tracking internalJonathan Brassow2008-04-25
| | | | | | | Remove internal module reference fields from the interface. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: move register functionsAlasdair G Kergon2008-04-25
| | | | | | Reorder a couple of functions in the file so the next patch is readable. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: clean interfaceHeinz Mauelshagen2008-04-25
| | | | | | | Clean up the dm-log interface to prepare for publishing it in include/linux. Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm kcopyd: clean interfaceHeinz Mauelshagen2008-04-25
| | | | | | | Clean up the kcopyd interface to prepare for publishing it in include/linux. Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm io: clean interfaceHeinz Mauelshagen2008-04-25
| | | | | | | Clean up the dm-io interface to prepare for publishing it in include/linux. Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm io: rename error to error_bitsAlasdair G Kergon2008-04-25
| | | | | | Rename 'error' to 'error_bits' for clarity. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm snapshot: store pointer to target instanceMikulas Patocka2008-04-25
| | | | | | | Save pointer to dm_target in dm_snapshot structure. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: move dirty region log code into separate moduleHeinz Mauelshagen2008-04-25
| | | | | | | | Move the dirty region log code into a separate module so other targets can share the code. Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm log: generalise name in messagesHeinz Mauelshagen2008-04-25
| | | | | | | | Change dm-log.c messages from "mirror log" to "dirty region log" as a new dm target wants to share this code. Signed-off-by: Heinz Mauelshagen <hjm@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid1: use list_split_initRobert P. J. Day2008-04-25
| | | | | | | Use shorter list_splice_init() for brevity. Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm snapshot: reduce default memory allocationMilan Broz2008-04-25
| | | | | | | | | Limit the amount of memory allocated per snapshot on systems with a large page size. (The larger default chunk size on these systems compensates for the smaller number of pages reserved.) Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm snapshot: fix chunksize sector conversionMikulas Patocka2008-04-25
| | | | | | | | | | | If a snapshot has a smaller chunksize than the page size the conversion to pages currently returns 0 instead of 1, causing: kernel BUG in mempool_resize. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: stable@kernel.org
* RAID: remove trailing space from printk lineNick Andrew2008-04-21
| | | | | | | | drivers/md/*.[ch] contains only one more printk line with a trailing space. Remove it. Signed-off-by: Nick Andrew <nick@nick-andrew.net> Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com>
* md: close a livelock window in handle_parity_checks5Dan Williams2008-04-11
| | | | | | | | | | | | | | | | | | If a failure is detected after a parity check operation has been initiated, but before it completes handle_parity_checks5 will never quiesce operations on the stripe. Explicitly handle this case by "canceling" the parity check, i.e. clear the STRIPE_OP_CHECK flags and queue the stripe on the handle list again to refresh any non-uptodate blocks. Kernel versions >= 2.6.23 are susceptible. Cc: <stable@kernel.org> Cc: NeilBrown <neilb@suse.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm io: write error bits form long not intAlasdair G Kergon2008-03-28
| | | | | | | | | | | | write_err is an unsigned long used with set_bit() so should not be passed around as unsigned int. http://bugzilla.kernel.org/show_bug.cgi?id=10271 Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm crypt: fix ctx pendingMilan Broz2008-03-28
| | | | | | | | | | | | | | | | | | | | | | | Fix regression in dm-crypt introduced in commit 3a7f6c990ad04e6f576a159876c602d14d6f7fef ("dm crypt: use async crypto"). If write requests need to be split into pieces, the code must not process them in parallel because the crypto context cannot be shared. So there can be parallel crypto operations on one part of the write, but only one write bio can be processed at a time. This is not optimal and the workqueue code needs to be optimized for parallel processing, but for now it solves the problem without affecting the performance of synchronous crypto operation (most of current dm-crypt users). http://bugzilla.kernel.org/show_bug.cgi?id=10242 http://bugzilla.kernel.org/show_bug.cgi?id=10207 Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Cc: "Rafael J. Wysocki" <rjw@sisk.pl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* drivers/md/raid5.c: fix printk warningsAndrew Morton2008-03-19
| | | | | | | | | | | | | | | | | gcc-3.4.5 on sparc64: drivers/md/raid5.c: In function `raid5_end_read_request': drivers/md/raid5.c:1147: warning: long long unsigned int format, long unsigned int arg (arg 4) drivers/md/raid5.c:1164: warning: long long unsigned int format, long unsigned int arg (arg 3) drivers/md/raid5.c:1170: warning: long long unsigned int format, long unsigned int arg (arg 3) sector_t is u64, and we don't know what type the architecture uses to implement u64 (on some it is unsigned long). Cc: Neil Brown <neilb@suse.de> Cc: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: remove the 'super' sysfs attribute from devices in an 'md' arrayNeilBrown2008-03-19
| | | | | | | | | | | | | | | | Exposing the binary blob which is the md 'super-block' via sysfs doesn't really fit with the whole sysfs model, and ever since commit 8118a859dc7abd873193986c77a8d9bdb877adc8 ("sysfs: fix off-by-one error in fill_read_buffer()") it doesn't actually work at all (as the size of the blob is often one page). (akpm: as in, fs/sysfs/file.c:fill_read_buffer() goes BUG) So just remove it altogether. It isn't really useful. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: reduce CPU wastage on idle md array with a write-intent bitmapNeilBrown2008-03-10
| | | | | | | | | | | | | | | | Recent patch titled Reduce CPU wastage on idle md array with a write-intent bitmap. would sometimes leave the array with dirty bitmap bits that stay dirty. A subsequent write would sort things out so it isn't a big problem, but should be fixed nonetheless. We need to make sure that when the bitmap becomes not "allclean", the daemon_sleep really does get set to a sensible value. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: fix formatting error in /proc/mdstatNeilBrown2008-03-10
| | | | | | | | | | | | | | | | | | | | If an md array is "auto-read-only", then this appears in /proc/mdstat as /dev/md0: active(auto-read-only) whereas if it is truely readonly, it appears as /dev/md0: active (read-only) The difference being a space. One program known to parse this file expects the space and gets badly confused. It will be fixed, but it would be best if what the kernel generates is more consistent too. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: the md RAID10 resync thread could cause a md RAID10 array deadlockK.Tanaka2008-03-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This message describes another issue about md RAID10 found by testing the 2.6.24 md RAID10 using new scsi fault injection framework. Abstract: When a scsi error results in disabling a disk during RAID10 recovery, the resync threads of md RAID10 could stall. This case, the raid array has already been broken and it may not matter. But I think stall is not preferable. If it occurs, even shutdown or reboot will fail because of resource busy. The deadlock mechanism: The r10bio_s structure has a "remaining" member to keep track of BIOs yet to be handled when recovering. The "remaining" counter is incremented when building a BIO in sync_request() and is decremented when finish a BIO in end_sync_write(). If building a BIO fails for some reasons in sync_request(), the "remaining" should be decremented if it has already been incremented. I found a case where this decrement is forgotten. This causes a md_do_sync() deadlock because md_do_sync() waits for md_done_sync() called by end_sync_write(), but end_sync_write() never calls md_done_sync() because of the "remaining" counter mismatch. For example, this problem would be reproduced in the following case: Personalities : [raid10] md0 : active raid10 sdf1[4] sde1[5](F) sdd1[2] sdc1[1] sdb1[6](F) 3919616 blocks 64K chunks 2 near-copies [4/2] [_UU_] [>....................] recovery = 2.2% (45376/1959808) finish=0.7min speed=45376K/sec This case, sdf1 is recovering, sdb1 and sde1 are disabled. An additional error with detaching sdd will cause a deadlock. md0 : active raid10 sdf1[4] sde1[5](F) sdd1[6](F) sdc1[1] sdb1[7](F) 3919616 blocks 64K chunks 2 near-copies [4/1] [_U__] [=>...................] recovery = 5.0% (99520/1959808) finish=5.9min speed=5237K/sec 2739 ? S< 0:17 [md0_raid10] 28608 ? D< 0:00 [md0_resync] 28629 pts/1 Ss 0:00 bash 28830 pts/1 R+ 0:00 ps ax 31819 ? D< 0:00 [kjournald] The resync thread keeps working, but actually it is deadlocked. Patch: By this patch, the remaining counter will be decremented if needed. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: fix possible raid1/raid10 deadlock on read error during resyncNeilBrown2008-03-04
| | | | | | | | | | | | | | | | | Thanks to K.Tanaka and the scsi fault injection framework, here is a fix for another possible deadlock in raid1/raid10 error handing. If a read request returns an error while a resync is happening and a resync request is pending, the attempt to fix the error will block until the resync progresses, and the resync will block until the read request completes. Thus a deadlock. This patch fixes the problem. Cc: "K.Tanaka" <k-tanaka@ce.jp.nec.com> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: don't attempt read-balancing for raid10 'far' layoutsKeld Simonsen2008-03-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch changes the disk to be read for layout "far > 1" to always be the disk with the lowest block address. Thus the chunks to be read will always be (for a fully functioning array) from the first band of stripes, and the raid will then work as a raid0 consisting of the first band of stripes. Some advantages: The fastest part which is the outer sectors of the disks involved will be used. The outer blocks of a disk may be as much as 100 % faster than the inner blocks. Average seek time will be smaller, as seeks will always be confined to the first part of the disks. Mixed disks with different performance characteristics will work better, as they will work as raid0, the sequential read rate will be number of disks involved times the IO rate of the slowest disk. If a disk is malfunctioning, the first disk which is working, and has the lowest block address for the logical block will be used. Signed-off-by: Keld Simonsen <keld@dkuug.dk> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: lock access to rdev attributes properlyNeilBrown2008-03-04
| | | | | | | | | | | | | | | | | | | | When we access attributes of an rdev (component device on an md array) through sysfs, we really need to lock the array against concurrent changes. We currently do that when we change an attribute, but not when we read an attribute. We need to lock when reading as well else rdev->mddev could become NULL while we are accessing it. So add appropriate locking (mddev_lock) to rdev_attr_show. rdev_size_store requires some extra care as well as it needs to unlock the mddev while scanning other mddevs for overlapping regions. We currently assume that rdev->mddev will still be unchanged after the scan, but that cannot be certain. So take a copy of rdev->mddev for use at the end of the function. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: make sure a reshape is started when device switches to read-writeNeilBrown2008-03-04
| | | | | | | | | | | | | | | | | | A resync/reshape/recovery thread will refuse to progress when the array is marked read-only. So whenever it mark it not read-only, it is important to wake up thread resync thread. There is one place we didn't do this. The problem manifests if the start_ro module parameters is set, and a raid5 array that is in the middle of a reshape (restripe) is started. The array will initially be semi-read-only (meaning it acts like it is readonly until the first write). So the reshape will not proceed. On the first write, the array will become read-write, but the reshape will not be started, and there is no event which will ever restart that thread. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: clean up irregularity with raid autodetectNeilBrown2008-03-04
| | | | | | | | | | | When a raid1 array is stopped, all components currently get added to the list for auto-detection. However we should really only add components that were found by autodetection in the first place. So add a flag to record that information, and use it. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: guard against possible bad array geometry in v1 metadataNeilBrown2008-03-04
| | | | | | | | | Make sure the data doesn't start before the end of the superblock when the superblock is at the start of the device. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: reduce CPU wastage on idle md array with a write-intent bitmapNeilBrown2008-03-04
| | | | | | | | | | | | | On an md array with a write-intent bitmap, a thread wakes up every few seconds and scans the bitmap looking for work to do. If the array is idle, there will be no work to do, but a lot of scanning is done to discover this. So cache the fact that the bitmap is completely clean, and avoid scanning the whole bitmap when the cache is known to be clean. Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* md: fix deadlock in md/raid1 and md/raid10 when handling a read errorNeilBrown2008-03-04
| | | | | | | | | | | | | | | | | | | | | | | | When handling a read error, we freeze the array to stop any other IO while attempting to over-write with correct data. This is done in the raid1d(raid10d) thread and must wait for all submitted IO to complete (except for requests that failed and are sitting in the retry queue - these are counted in ->nr_queue and will stay there during a freeze). However write requests need attention from raid1d as bitmap updates might be required. This can cause a deadlock as raid1 is waiting for requests to finish that themselves need attention from raid1d. So we create a new function 'flush_pending_writes' to give that attention, and call it in freeze_array to be sure that we aren't waiting on raid1d. Thanks to "K.Tanaka" <k-tanaka@ce.jp.nec.com> for finding and reporting this problem. Cc: "K.Tanaka" <k-tanaka@ce.jp.nec.com> Signed-off-by: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm-raid1.c: fix NULL dereferencesAdrian Bunk2008-02-19
| | | | | | | | | | This patch fixes two NULL dereferences introduced by commit 06386bbfd2441416875d0403d405c56822f6ebac and spotted by the Coverity checker. Signed-off-by: Adrian Bunk <bunk@kernel.org> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* d_path: Make d_path() use a struct pathJan Blunck2008-02-15
| | | | | | | | | | | | | | | | d_path() is used on a <dentry,vfsmount> pair. Lets use a struct path to reflect this. [akpm@linux-foundation.org: fix build in mm/memory.c] Signed-off-by: Jan Blunck <jblunck@suse.de> Acked-by: Bryan Wu <bryan.wu@analog.com> Acked-by: Christoph Hellwig <hch@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Neil Brown <neilb@suse.de> Cc: Michael Halcrow <mhalcrow@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* d_path: Make seq_path() use a struct path argumentJan Blunck2008-02-15
| | | | | | | | | | | | | seq_path() is always called with a dentry and a vfsmount from a struct path. Make seq_path() take it directly as an argument. Signed-off-by: Jan Blunck <jblunck@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Neil Brown <neilb@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Introduce path_put()Jan Blunck2008-02-15
| | | | | | | | | | | | | | | | | | | * Add path_put() functions for releasing a reference to the dentry and vfsmount of a struct path in the right order * Switch from path_release(nd) to path_put(&nd->path) * Rename dput_path() to path_put_conditional() [akpm@linux-foundation.org: fix cifs] Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Cc: <linux-fsdevel@vger.kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Steven French <sfrench@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Embed a struct path into struct nameidata instead of nd->{dentry,mnt}Jan Blunck2008-02-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is the central patch of a cleanup series. In most cases there is no good reason why someone would want to use a dentry for itself. This series reflects that fact and embeds a struct path into nameidata. Together with the other patches of this series - it enforced the correct order of getting/releasing the reference count on <dentry,vfsmount> pairs - it prepares the VFS for stacking support since it is essential to have a struct path in every place where the stack can be traversed - it reduces the overall code size: without patch series: text data bss dec hex filename 5321639 858418 715768 6895825 6938d1 vmlinux with patch series: text data bss dec hex filename 5320026 858418 715768 6894212 693284 vmlinux This patch: Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere. [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix cifs] [akpm@linux-foundation.org: fix smack] Signed-off-by: Jan Blunck <jblunck@suse.de> Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Acked-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm-raid1 breakage on 64bitAl Viro2008-02-13
| | | | | | | test_and_set_bit() on address of uint32_t is a Bad Idea(tm)... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* dm raid1: report fault statusJonathan Brassow2008-02-07
| | | | | | | | | | | | | | | This patch adds extra information to the mirror status output, so that it can be determined which device(s) have failed. For each mirror device, a character is printed indicating the most severe error encountered. The characters are: * A => Alive - No failures * D => Dead - A write failure occurred leaving mirror out-of-sync * S => Sync - A sychronization failure occurred, mirror out-of-sync * R => Read - A read failure occurred, mirror data unaffected This allows userspace to properly reconfigure the mirror set. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid1: handle read failuresJonathan Brassow2008-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | This patch gives the ability to respond-to/record device failures that happen during read operations. It also adds the ability to read from mirror devices that are not the primary if they are in-sync. There are essentially two read paths in mirroring; the direct path and the queued path. When a read request is mapped, if the region is 'in-sync' the direct path is taken; otherwise the queued path is taken. If the direct path is taken, we must record bio information so that if the read fails we can retry it. We then discover the status of a direct read through mirror_end_io. If the read has failed, we will mark the device from which the read was attempted as failed (so we don't try to read from it again), restore the bio and try again. If the queued path is taken, we discover the results of the read from 'read_callback'. If the device failed, we will mark the device as failed and attempt the read again if there is another device where this region is known to be 'in-sync'. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid1: fix EIO after log failureJonathan Brassow2008-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the ability to requeue write I/O to core device-mapper when there is a log device failure. If a write to the log produces and error, the pending writes are put on the "failures" list. Since the log is marked as failed, they will stay on the failures list until a suspend happens. Suspends come in two phases, presuspend and postsuspend. We must make sure that all the writes on the failures list are requeued in the presuspend phase (a requirement of dm core). This means that recovery must be complete (because writes may be delayed behind it) and the failures list must be requeued before we return from presuspend. The mechanisms to ensure recovery is complete (or stopped) was already in place, but needed to be moved from postsuspend to presuspend. We rely on 'flush_workqueue' to ensure that the mirror thread is complete and therefore, has requeued all writes in the failures list. Because we are using flush_workqueue, we must ensure that no additional 'queue_work' calls will produce additional I/O that we need to requeue (because once we return from presuspend, we are unable to do anything about it). 'queue_work' is called in response to the following functions: - complete_resync_work = NA, recovery is stopped - rh_dec (mirror_end_io) = NA, only calls 'queue_work' if it is ready to recover the region (recovery is stopped) or it needs to clear the region in the log* **this doesn't get called while suspending** - rh_recovery_end = NA, recovery is stopped - rh_recovery_start = NA, recovery is stopped - write_callback = 1) Writes w/o failures simply call bio_endio -> mirror_end_io -> rh_dec (see rh_dec above) 2) Writes with failures are put on the failures list and queue_work is called** ** write_callbacks don't happen during suspend ** - do_failures = NA, 'queue_work' not called if suspending - add_mirror (initialization) = NA, only done on mirror creation - queue_bio = NA, 1) delayed I/O scheduled before flush_workqueue is called. 2) No more I/Os are being issued. 3) Re-attempted READs can still be handled. (Write completions are handled through rh_dec/ write_callback - mention above - and do not use queue_bio.) Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid1: handle recovery failuresJonathan Brassow2008-02-07
| | | | | | | | | | This patch adds the calls to 'fail_mirror' if an error occurs during mirror recovery (aka resynchronization). 'fail_mirror' is responsible for recording the type of error by mirror device and ensuring an event gets raised for the purpose of notifying userspace. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm raid1: handle write failuresJonathan Brassow2008-02-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch gives mirror the ability to handle device failures during normal write operations. The 'write_callback' function is called when a write completes. If all the writes failed or succeeded, we report failure or success respectively. If some of the writes failed, we call fail_mirror; which increments the error count for the device, notes the type of error encountered (DM_RAID1_WRITE_ERROR), and selects a new primary (if necessary). Note that the primary device can never change while the mirror is not in-sync (IOW, while recovery is happening.) This means that the scenario where a failed write changes the primary and gives recovery_complete a chance to misread the primary never happens. The fact that the primary can change has necessitated the change to the default_mirror field. We need to protect against reading garbage while the primary changes. We then add the bio to a new list in the mirror set, 'failures'. For every bio in the 'failures' list, we call a new function, '__bio_mark_nosync', where we mark the region 'not-in-sync' in the log and properly set the region state as, RH_NOSYNC. Userspace must also be notified of the failure. This is done by 'raising an event' (dm_table_event()). If fail_mirror is called in process context the event can be raised right away. If in interrupt context, the event is deferred to the kmirrord thread - which raises the event if 'event_waiting' is set. Backwards compatibility is maintained by ignoring errors if the DM_FEATURES_HANDLE_ERRORS flag is not present. Signed-off-by: Jonathan Brassow <jbrassow@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
* dm snapshot: combine consecutive exceptions in memoryMilan Broz2008-02-07
| | | | | | | | | Provided sector_t is 64 bits, reduce the in-memory footprint of the snapshot exception table by the simple method of using unused bits of the chunk number to combine consecutive entries. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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