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* HWPOISON: add page flags filterWu Fengguang2009-12-165-0/+43
| | | | | | | | | | | | | | | | | | | | | When specified, only poison pages if ((page_flags & mask) == value). - corrupt-filter-flags-mask - corrupt-filter-flags-value This allows stress testing of many kinds of pages. Strictly speaking, the buddy pages requires taking zone lock, to avoid setting PG_hwpoison on a "was buddy but now allocated to someone" page. However we can just do nothing because we set PG_locked in the beginning, this prevents the page allocator from allocating it to someone. (It will BUG() on the unexpected PG_locked, which is fine for hwpoison testing.) [AK: Add select PROC_PAGE_MONITOR to satisfy dependency] CC: Nick Piggin <npiggin@suse.de> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* mm: export stable page flagsWu Fengguang2009-12-163-42/+51
| | | | | | | | | | | | | | | Rename get_uflags() to stable_page_flags() and make it a global function for use in the hwpoison page flags filter, which need to compare user page flags with the value provided by user space. Also move KPF_* to kernel-page-flags.h for use by user space tools. Acked-by: Matt Mackall <mpm@selenic.com> Signed-off-by: Andi Kleen <ak@linux.intel.com> CC: Nick Piggin <npiggin@suse.de> CC: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: limit hwpoison injector to known page typesWu Fengguang2009-12-163-3/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | __memory_failure()'s workflow is set PG_hwpoison //... unset PG_hwpoison if didn't pass hwpoison filter That could kill unrelated process if it happens to page fault on the page with the (temporary) PG_hwpoison. The race should be big enough to appear in stress tests. Fix it by grabbing the page and checking filter at inject time. This also avoids the very noisy "Injecting memory failure..." messages. - we don't touch madvise() based injection, because the filters are generally not necessary for it. - if we want to apply the filters to h/w aided injection, we'd better to rearrange the logic in __memory_failure() instead of this patch. AK: fix documentation, use drain all, cleanups CC: Haicheng Li <haicheng.li@intel.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: add fs/device filtersWu Fengguang2009-12-164-0/+72
| | | | | | | | | | | | | | | | | | | | | | | Filesystem data/metadata present the most tricky-to-isolate pages. It requires careful code review and stress testing to get them right. The fs/device filter helps to target the stress tests to some specific filesystem pages. The filter condition is block device's major/minor numbers: - corrupt-filter-dev-major - corrupt-filter-dev-minor When specified (non -1), only page cache pages that belong to that device will be poisoned. The filters are checked reliably on the locked and refcounted page. Haicheng: clear PG_hwpoison and drop bad page count if filter not OK AK: Add documentation CC: Haicheng Li <haicheng.li@intel.com> CC: Nick Piggin <npiggin@suse.de> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: return 0 to indicate success reliablyWu Fengguang2009-12-161-2/+6
| | | | | | | | | | | | Return 0 to indicate success, when - action result is RECOVERED or DELAYED - no extra page reference Note that dirty swapcache pages are kept in swapcache, so can have one more reference count. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: make semantics of IGNORED/DELAYED clearWu Fengguang2009-12-161-15/+7
| | | | | | | | | | | | | Change semantics for - IGNORED: not handled; it may well be _unsafe_ - DELAYED: to be handled later; it is _safe_ With this change, - IGNORED/FAILED mean (maybe) Error - DELAYED/RECOVERED mean Success Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: Add unpoisoning supportWu Fengguang2009-12-165-9/+114
| | | | | | | | | | | | | | | | | | The unpoisoning interface is useful for stress testing tools to reclaim poisoned pages (to prevent OOM) There is no hardware level unpoisioning, so this cannot be used for real memory errors, only for software injected errors. Note that it may leak pages silently - those who have been removed from LRU cache, but not isolated from page cache/swap cache at hwpoison time. Especially the stress test of dirty swap cache pages shall reboot system before exhausting memory. AK: Fix comments, add documentation, add printks, rename symbol Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: detect free buddy pages explicitlyWu Fengguang2009-12-163-2/+31
| | | | | | | | | | Most free pages in the buddy system have no PG_buddy set. Introduce is_free_buddy_page() for detecting them reliably. CC: Nick Piggin <npiggin@suse.de> CC: Mel Gorman <mel@linux.vnet.ibm.com> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: remove the free buddy page handlerWu Fengguang2009-12-161-10/+4
| | | | | | | | The buddy page has already be handled in the very beginning. So remove redundant code. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: introduce delete_from_lru_cache()Wu Fengguang2009-12-161-8/+37
| | | | | | | | | | Introduce delete_from_lru_cache() to - clear PG_active, PG_unevictable to avoid complains at unpoison time - move the isolate_lru_page() call back to the handlers instead of the entrance of __memory_failure(), this is more hwpoison filter friendly Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: comment dirty swapcache pagesWu Fengguang2009-12-161-0/+4
| | | | | | | AK: Improve comment Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: comment the possible set_page_dirty() raceWu Fengguang2009-12-161-0/+2
| | | | | Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: abort on failed unmapWu Fengguang2009-12-161-5/+15
| | | | | | | | Don't try to isolate a still mapped page. Otherwise we will hit the BUG_ON(page_mapped(page)) in __remove_from_page_cache(). Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: Turn ref argument into flags argumentAndi Kleen2009-12-163-4/+8
| | | | | | | | | Now that "ref" is just a boolean turn it into a flags argument. First step is only a single flag that makes the code's intention more clear, but more may follow. Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: avoid grabbing the page count multiple times during madvise injectionWu Fengguang2009-12-162-5/+4
| | | | | | | | | If page is double referenced in madvise_hwpoison() and __memory_failure(), remove_mapping() will fail because it expects page_count=2. Fix it by not grabbing extra page count in __memory_failure(). Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: return ENXIO on invalid page numberWu Fengguang2009-12-161-6/+6
| | | | | | | | | | Use a different errno than the usual EIO for invalid page numbers. This is mainly for better reporting for the injector. This also avoids calling action_result() with invalid pfn. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: remove the anonymous entryWu Fengguang2009-12-161-1/+0
| | | | | | | | (PG_swapbacked && !PG_lru) pages should not happen. Better to treat them as unknown pages. Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* page-types: add standard GPL license headerWu Fengguang2009-12-161-2/+13
| | | | | Signed-off-by: Wu Fengguang <fengguang.wu@intel.com> Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: Be more aggressive at freeing non LRU cachesAndi Kleen2009-12-162-0/+23
| | | | | | | | | | | | | shake_page handles more types of page caches than lru_drain_all() - per cpu page allocator pages - per CPU LRU Stops early when the page became free. Used in followon patches. Signed-off-by: Andi Kleen <ak@linux.intel.com>
* HWPOISON: Add Andi Kleen as hwpoison maintainer to MAINTAINERSAndi Kleen2009-12-161-0/+9
| | | | Signed-off-by: Andi Kleen <ak@linux.intel.com>
* mfd: compile fix for twl4030 renamingStephen Rothwell2009-12-151-5/+5
| | | | | | | | | | | | | | | Caused by commit 0b83ddebc6e884dc0221358cf68c461520fbdd8e ("MFD: twl4030: add twl4030_codec MFD as a new child to the core") interacting with commit b07682b6056eb6701f8cb86aa5800e6f2ea7919b ("mfd: Rename twl4030* driver files to enable re-use"). This file seems to have been missed in the renaming. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Peter Ujfalusi <peter.ujfalusi@nokia.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'for-linus' of git://oss.sgi.com/xfs/xfsLinus Torvalds2009-12-1570-2836/+2369
|\ | | | | | | | | | | | | * 'for-linus' of git://oss.sgi.com/xfs/xfs: xfs: event tracing support xfs: change the xfs_iext_insert / xfs_iext_remove xfs: cleanup bmap extent state macros
| * xfs: event tracing supportChristoph Hellwig2009-12-1470-2592/+2151
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the old xfs tracing support that could only be used with the out of tree kdb and xfsidbg patches to use the generic event tracer. To use it make sure CONFIG_EVENT_TRACING is enabled and then enable all xfs trace channels by: echo 1 > /sys/kernel/debug/tracing/events/xfs/enable or alternatively enable single events by just doing the same in one event subdirectory, e.g. echo 1 > /sys/kernel/debug/tracing/events/xfs/xfs_ihold/enable or set more complex filters, etc. In Documentation/trace/events.txt all this is desctribed in more detail. To reads the events do a cat /sys/kernel/debug/tracing/trace Compared to the last posting this patch converts the tracing mostly to the one tracepoint per callsite model that other users of the new tracing facility also employ. This allows a very fine-grained control of the tracing, a cleaner output of the traces and also enables the perf tool to use each tracepoint as a virtual performance counter, allowing us to e.g. count how often certain workloads git various spots in XFS. Take a look at http://lwn.net/Articles/346470/ for some examples. Also the btree tracing isn't included at all yet, as it will require additional core tracing features not in mainline yet, I plan to deliver it later. And the really nice thing about this patch is that it actually removes many lines of code while adding this nice functionality: fs/xfs/Makefile | 8 fs/xfs/linux-2.6/xfs_acl.c | 1 fs/xfs/linux-2.6/xfs_aops.c | 52 - fs/xfs/linux-2.6/xfs_aops.h | 2 fs/xfs/linux-2.6/xfs_buf.c | 117 +-- fs/xfs/linux-2.6/xfs_buf.h | 33 fs/xfs/linux-2.6/xfs_fs_subr.c | 3 fs/xfs/linux-2.6/xfs_ioctl.c | 1 fs/xfs/linux-2.6/xfs_ioctl32.c | 1 fs/xfs/linux-2.6/xfs_iops.c | 1 fs/xfs/linux-2.6/xfs_linux.h | 1 fs/xfs/linux-2.6/xfs_lrw.c | 87 -- fs/xfs/linux-2.6/xfs_lrw.h | 45 - fs/xfs/linux-2.6/xfs_super.c | 104 --- fs/xfs/linux-2.6/xfs_super.h | 7 fs/xfs/linux-2.6/xfs_sync.c | 1 fs/xfs/linux-2.6/xfs_trace.c | 75 ++ fs/xfs/linux-2.6/xfs_trace.h | 1369 +++++++++++++++++++++++++++++++++++++++++ fs/xfs/linux-2.6/xfs_vnode.h | 4 fs/xfs/quota/xfs_dquot.c | 110 --- fs/xfs/quota/xfs_dquot.h | 21 fs/xfs/quota/xfs_qm.c | 40 - fs/xfs/quota/xfs_qm_syscalls.c | 4 fs/xfs/support/ktrace.c | 323 --------- fs/xfs/support/ktrace.h | 85 -- fs/xfs/xfs.h | 16 fs/xfs/xfs_ag.h | 14 fs/xfs/xfs_alloc.c | 230 +----- fs/xfs/xfs_alloc.h | 27 fs/xfs/xfs_alloc_btree.c | 1 fs/xfs/xfs_attr.c | 107 --- fs/xfs/xfs_attr.h | 10 fs/xfs/xfs_attr_leaf.c | 14 fs/xfs/xfs_attr_sf.h | 40 - fs/xfs/xfs_bmap.c | 507 +++------------ fs/xfs/xfs_bmap.h | 49 - fs/xfs/xfs_bmap_btree.c | 6 fs/xfs/xfs_btree.c | 5 fs/xfs/xfs_btree_trace.h | 17 fs/xfs/xfs_buf_item.c | 87 -- fs/xfs/xfs_buf_item.h | 20 fs/xfs/xfs_da_btree.c | 3 fs/xfs/xfs_da_btree.h | 7 fs/xfs/xfs_dfrag.c | 2 fs/xfs/xfs_dir2.c | 8 fs/xfs/xfs_dir2_block.c | 20 fs/xfs/xfs_dir2_leaf.c | 21 fs/xfs/xfs_dir2_node.c | 27 fs/xfs/xfs_dir2_sf.c | 26 fs/xfs/xfs_dir2_trace.c | 216 ------ fs/xfs/xfs_dir2_trace.h | 72 -- fs/xfs/xfs_filestream.c | 8 fs/xfs/xfs_fsops.c | 2 fs/xfs/xfs_iget.c | 111 --- fs/xfs/xfs_inode.c | 67 -- fs/xfs/xfs_inode.h | 76 -- fs/xfs/xfs_inode_item.c | 5 fs/xfs/xfs_iomap.c | 85 -- fs/xfs/xfs_iomap.h | 8 fs/xfs/xfs_log.c | 181 +---- fs/xfs/xfs_log_priv.h | 20 fs/xfs/xfs_log_recover.c | 1 fs/xfs/xfs_mount.c | 2 fs/xfs/xfs_quota.h | 8 fs/xfs/xfs_rename.c | 1 fs/xfs/xfs_rtalloc.c | 1 fs/xfs/xfs_rw.c | 3 fs/xfs/xfs_trans.h | 47 + fs/xfs/xfs_trans_buf.c | 62 - fs/xfs/xfs_vnodeops.c | 8 70 files changed, 2151 insertions(+), 2592 deletions(-) Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * xfs: change the xfs_iext_insert / xfs_iext_removeChristoph Hellwig2009-12-144-26/+38
| | | | | | | | | | | | | | | | | | | | Change the xfs_iext_insert / xfs_iext_remove prototypes to pass more information which will allow pushing the trace points from the callers into those functions. This includes folding the whichfork information into the state variable to minimize the addition stack footprint. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
| * xfs: cleanup bmap extent state macrosChristoph Hellwig2009-12-142-222/+184
| | | | | | | | | | | | | | | | | | Cleanup the extent state macros in the bmap code to use one common set of flags that we can pass to the tracing code later and remove a lot of the macro obsfucation. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dmLinus Torvalds2009-12-1523-889/+2349
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/agk/linux-2.6-dm: (80 commits) dm snapshot: use merge origin if snapshot invalid dm snapshot: report merge failure in status dm snapshot: merge consecutive chunks together dm snapshot: trigger exceptions in remaining snapshots during merge dm snapshot: delay merging a chunk until writes to it complete dm snapshot: queue writes to chunks being merged dm snapshot: add merging dm snapshot: permit only one merge at once dm snapshot: support barriers in snapshot merge target dm snapshot: avoid allocating exceptions in merge dm snapshot: rework writing to origin dm snapshot: add merge target dm exception store: add merge specific methods dm snapshot: create function for chunk_is_tracked wait dm snapshot: make bio optional in __origin_write dm mpath: reject messages when device is suspended dm: export suspended state to targets dm: rename dm_suspended to dm_suspended_md dm: swap target postsuspend call and setting suspended flag dm crypt: add plain64 iv ...
| * | dm snapshot: use merge origin if snapshot invalidMikulas Patocka2009-12-101-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | If the snapshot we are merging became invalid (e.g. it ran out of space) redirect all I/O directly to the origin device. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm snapshot: report merge failure in statusMike Snitzer2009-12-101-2/+28
| | | | | | | | | | | | | | | | | | | | | | | | Set 'merge_failed' flag if a snapshot fails to merge. Update snapshot_status() to report "Merge failed" if 'merge_failed' is set. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm snapshot: merge consecutive chunks togetherMike Snitzer2009-12-101-10/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | s->store->type->prepare_merge returns the number of chunks that can be copied linearly working backwards from the returned chunk number. For example, if it returns 3 chunks with old_chunk == 10 and new_chunk == 20, then chunk 20 can be copied to 10, chunk 19 to 9 and 18 to 8. Until now kcopyd only copied one chunk at a time. This patch now copies the full set at once. Consequently, snapshot_merge_process() needs to delay the merging of all chunks if any have writes in progress, not just the first chunk in the region that is to be merged. snapshot-merge's performance is now comparable to the original snapshot-origin target. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm snapshot: trigger exceptions in remaining snapshots during mergeMikulas Patocka2009-12-101-0/+83
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When there is one merging snapshot and other non-merging snapshots, snapshot_merge_process() must make exceptions in the non-merging snapshots. Use a sequence count to resolve the race between I/O to chunks that are about to be merged. The count increases each time an exception reallocation finishes. Use wait_event() to wait until the count changes. 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>
| * | dm snapshot: delay merging a chunk until writes to it completeMikulas Patocka2009-12-101-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | Track writes to chunks that are currently being merged and delay merging a chunk until all writes to that chunk finish. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm snapshot: queue writes to chunks being mergedMikulas Patocka2009-12-101-13/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | While a set of chunks is being merged, any overlapping writes need to be queued. 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>
| * | dm snapshot: add mergingMikulas Patocka2009-12-102-6/+244
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merging is started when origin is resumed and it is stopped when origin is suspended or when the merging snapshot is destroyed or errors are detected. Merging is not yet interlocked with writes: this will be handled in subsequent patches. The code relies on callbacks from a private kcopyd thread. 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>
| * | dm snapshot: permit only one merge at onceMikulas Patocka2009-12-101-6/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | Merging more than one snapshot is not supported, so prevent this happening. 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>
| * | dm snapshot: support barriers in snapshot merge targetMike Snitzer2009-12-101-3/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sets num_flush_requests=2 to support flushing both the origin and cow devices used by the snapshot-merge target. Also, snapshot_ctr() now gets the origin device using FMODE_WRITE if the target is snapshot-merge (which writes to the origin device). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm snapshot: avoid allocating exceptions in mergeMikulas Patocka2009-12-101-1/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The snapshot-merge target should not allocate new exceptions because the intent is to merge all of its exceptions as quickly and safely as possible. This patch introduces the snapshot-merge mapping function and updates __origin_write() so that it doesn't allocate exceptions on any snapshots that are being merged. If a write request to a merging snapshot device is to be dispatched directly to the origin (because the chunk is not remapped or was already merged), snapshot_merge_map() must make exceptions in other snapshots so calls do_origin(). 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>
| * | dm snapshot: rework writing to originMikulas Patocka2009-12-101-106/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To track the completion of exceptions relating to the same location on the device, the current code selects one exception as primary_pe, links the other exceptions to it and uses reference counting to wait until all the reallocations are complete. It is considered too complicated to extend this code to handle the new snapshot-merge target, where sets of non-overlapping chunks would also need to become linked. Instead, a simpler (but less efficient) approach is taken. Bios are linked to one exception. When it completes, bios are simply retried, and if other related exceptions are still outstanding, they'll get queued again to wait for another one. 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>
| * | dm snapshot: add merge targetMikulas Patocka2009-12-102-17/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The snapshot-merge target allows a snapshot to be merged back into the snapshot's origin device. One anticipated use of snapshot merging is the rollback of filesystems to back out problematic system upgrades. This patch adds snapshot-merge target management to both dm_snapshot_init() and dm_snapshot_exit(). As an initial place-holder, snapshot-merge is identical to the snapshot target. Documentation is provided. 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>
| * | dm exception store: add merge specific methodsMikulas Patocka2009-12-102-2/+129
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add functions that decide how many consecutive chunks of snapshot to merge back into the origin next and to update the metadata afterwards. prepare_merge provides a pointer to the most recent still-to-be-merged chunk and returns how many previous ones are consecutive and can be processed together. commit_merge removes the nr_merged most-recent chunks permanently from the exception store. The number must not exceed that returned by prepare_merge. Introduce NUM_SNAPSHOT_HDR_CHUNKS to show where the snapshot header chunk is accounted for. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Reviewed-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm snapshot: create function for chunk_is_tracked waitMike Snitzer2009-12-101-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move the __chunk_is_tracked() loop into a separate function as we will also need to call it from the write path in the rare case of conflicting writes to the same chunk. Originally introduced in commit a8d41b59f3f5a7ac19452ef442a7fc1b5fa17366 ("dm snapshot: fix race during exception creation"). Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm snapshot: make bio optional in __origin_writeMikulas Patocka2009-12-101-5/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To support the merging of snapshots back into their origin we need to trigger exceptions in other snapshots not being merged without any incoming bio on the origin device. The bio parameter to __origin_write() becomes optional and the sector needs supplying separately. 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>
| * | dm mpath: reject messages when device is suspendedKiyoshi Ueda2009-12-101-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch rejects messages that can generate I/O while the device itself is suspended. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm: export suspended state to targetsKiyoshi Ueda2009-12-102-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the exported dm_suspended() function so that targets can check whether or not they are suspended. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm: rename dm_suspended to dm_suspended_mdKiyoshi Ueda2009-12-105-12/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch renames dm_suspended() to dm_suspended_md() and keeps it internal to dm. No functional change. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm: swap target postsuspend call and setting suspended flagKiyoshi Ueda2009-12-101-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch moves DMF_SUSPENDED flag set before postsuspend. No one should care about the ordering, because the flag set and the postsuspend are protected by a single lock, md->suspend_lock, and all strict flag-checkers take the lock. Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Mike Anderson <andmike@linux.vnet.ibm.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm crypt: add plain64 ivMilan Broz2009-12-101-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The default plain IV is 32-bit only. This plain64 IV provides a compatible mode for encrypted devices bigger than 4TB. Signed-off-by: Milan Broz <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm: trace request based remappingJun'ichi Nomura2009-12-101-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a remapping trace to request-based dm. BIO-based dm already has the equivalent tracepoint. For example, under this dm stack (linear LV on multipath): # dmsetup ls --tree -o ascii vg-lv0 (253:1) `-mpath0 (253:0) |- (8:160) |- (66:80) |- (65:176) `- (65:160) Trace of 'dd of=/dev/vg/lv0 bs=128k count=1 oflag=direct' looks like this: without the patch: dd-6674 [000] 539.727384: block_bio_queue: 253,1 WS 0 + 256 [dd] dd-6674 [000] 539.727392: block_remap: 253,0 WS 384 + 256 <- (253,1) 0 dd-6674 [000] 539.727394: block_bio_queue: 253,0 WS 384 + 256 [dd] dd-6674 [000] 539.727405: block_getrq: 253,0 WS 384 + 256 [dd] dd-6674 [000] 539.727409: block_plug: [dd] dd-6674 [000] 539.727410: block_rq_insert: 253,0 W 0 () 384 + 256 [dd] dd-6674 [000] 539.727416: block_rq_issue: 253,0 W 0 () 384 + 256 [dd] dd-6674 [000] 539.727426: block_rq_insert: 65,176 W 0 () 384 + 256 [dd] dd-6674 [000] 539.727427: block_rq_issue: 65,176 W 0 () 384 + 256 [dd] ... and with the patch: (the line with '**' is the trace added by this patch) dd-6617 [002] 162.914301: block_bio_queue: 253,1 WS 0 + 256 [dd] dd-6617 [002] 162.914314: block_remap: 253,0 WS 384 + 256 <- (253,1) 0 dd-6617 [002] 162.914316: block_bio_queue: 253,0 WS 384 + 256 [dd] dd-6617 [002] 162.914331: block_getrq: 253,0 WS 384 + 256 [dd] dd-6617 [002] 162.914335: block_plug: [dd] dd-6617 [002] 162.914337: block_rq_insert: 253,0 W 0 () 384 + 256 [dd] dd-6617 [002] 162.914347: block_rq_issue: 253,0 W 0 () 384 + 256 [dd] **dd-6617 [002] 162.914356: block_rq_remap: 65,176 W 384 + 256 <- (253,0) 384 dd-6617 [002] 162.914358: block_rq_insert: 65,176 W 0 () 384 + 256 [dd] dd-6617 [002] 162.914359: block_rq_issue: 65,176 W 0 () 384 + 256 [dd] ... Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm snapshot: allow live exception store handover between tablesMike Snitzer2009-12-101-27/+236
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Permit in-use snapshot exception data to be 'handed over' from one snapshot instance to another. This is a pre-requisite for patches that allow the changes made in a snapshot device to be merged back into its origin device and also allows device resizing. The basic call sequence is: dmsetup load new_snapshot (referencing the existing in-use cow device) - the ctr code detects that the cow is already in use and allows the two snapshot target instances to be linked together dmsetup suspend original_snapshot dmsetup resume new_snapshot - the new_snapshot becomes live, and if anything now tries to access the original one it will receive -EIO dmsetup remove original_snapshot (There can only be two snapshot targets referencing the same cow device simultaneously.) Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm: keep old table until after resume succeededAlasdair G Kergon2009-12-103-22/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When swapping a new table into place, retain the old table until its replacement is in place. An old check for an empty table is removed because this is enforced in populate_table(). __unbind() becomes redundant when followed by __bind(). Signed-off-by: Alasdair G Kergon <agk@redhat.com>
| * | dm: bind new table before destroying oldAlasdair G Kergon2009-12-102-5/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When replacing a mapped device's table during a 'resume', delay the destruction of the old table until the new one is successfully in place. This will make it easier for a later patch to transfer internal state information from the old table to the new one (something we do not currently support) while giving us more options for reversion if a later part of the operation fails. Devices are always in the suspended state during dm_swap_table(). This patch reinforces the requirement that all I/O must have been flushed from the table targets while in this state (including any in workqueues). In the case of 'noflush' suspending, unprocessed I/O should have been 'pushed back' to the dm core prior to this point, for resubmission after the new table is in place. Signed-off-by: Alasdair G Kergon <agk@redhat.com>
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