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2017-07-08Merge tag 'for-linus-v4.13-2' of ↵Linus Torvalds1-1/+3
git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux Pull Writeback error handling updates from Jeff Layton: "This pile represents the bulk of the writeback error handling fixes that I have for this cycle. Some of the earlier patches in this pile may look trivial but they are prerequisites for later patches in the series. The aim of this set is to improve how we track and report writeback errors to userland. Most applications that care about data integrity will periodically call fsync/fdatasync/msync to ensure that their writes have made it to the backing store. For a very long time, we have tracked writeback errors using two flags in the address_space: AS_EIO and AS_ENOSPC. Those flags are set when a writeback error occurs (via mapping_set_error) and are cleared as a side-effect of filemap_check_errors (as you noted yesterday). This model really sucks for userland. Only the first task to call fsync (or msync or fdatasync) will see the error. Any subsequent task calling fsync on a file will get back 0 (unless another writeback error occurs in the interim). If I have several tasks writing to a file and calling fsync to ensure that their writes got stored, then I need to have them coordinate with one another. That's difficult enough, but in a world of containerized setups that coordination may even not be possible. But wait...it gets worse! The calls to filemap_check_errors can be buried pretty far down in the call stack, and there are internal callers of filemap_write_and_wait and the like that also end up clearing those errors. Many of those callers ignore the error return from that function or return it to userland at nonsensical times (e.g. truncate() or stat()). If I get back -EIO on a truncate, there is no reason to think that it was because some previous writeback failed, and a subsequent fsync() will (incorrectly) return 0. This pile aims to do three things: 1) ensure that when a writeback error occurs that that error will be reported to userland on a subsequent fsync/fdatasync/msync call, regardless of what internal callers are doing 2) report writeback errors on all file descriptions that were open at the time that the error occurred. This is a user-visible change, but I think most applications are written to assume this behavior anyway. Those that aren't are unlikely to be hurt by it. 3) document what filesystems should do when there is a writeback error. Today, there is very little consistency between them, and a lot of cargo-cult copying. We need to make it very clear what filesystems should do in this situation. To achieve this, the set adds a new data type (errseq_t) and then builds new writeback error tracking infrastructure around that. Once all of that is in place, we change the filesystems to use the new infrastructure for reporting wb errors to userland. Note that this is just the initial foray into cleaning up this mess. There is a lot of work remaining here: 1) convert the rest of the filesystems in a similar fashion. Once the initial set is in, then I think most other fs' will be fairly simple to convert. Hopefully most of those can in via individual filesystem trees. 2) convert internal waiters on writeback to use errseq_t for detecting errors instead of relying on the AS_* flags. I have some draft patches for this for ext4, but they are not quite ready for prime time yet. This was a discussion topic this year at LSF/MM too. If you're interested in the gory details, LWN has some good articles about this: https://lwn.net/Articles/718734/ https://lwn.net/Articles/724307/" * tag 'for-linus-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux: btrfs: minimal conversion to errseq_t writeback error reporting on fsync xfs: minimal conversion to errseq_t writeback error reporting ext4: use errseq_t based error handling for reporting data writeback errors fs: convert __generic_file_fsync to use errseq_t based reporting block: convert to errseq_t based writeback error tracking dax: set errors in mapping when writeback fails Documentation: flesh out the section in vfs.txt on storing and reporting writeback errors mm: set both AS_EIO/AS_ENOSPC and errseq_t in mapping_set_error fs: new infrastructure for writeback error handling and reporting lib: add errseq_t type and infrastructure for handling it mm: don't TestClearPageError in __filemap_fdatawait_range mm: clear AS_EIO/AS_ENOSPC when writeback initiation fails jbd2: don't clear and reset errors after waiting on writeback buffer: set errors in mapping at the time that the error occurs fs: check for writeback errors after syncing out buffers in generic_file_fsync buffer: use mapping_set_error instead of setting the flag mm: fix mapping_set_error call in me_pagecache_dirty
2017-07-07Merge tag 'libnvdimm-for-4.13' of ↵Linus Torvalds1-4/+5
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "libnvdimm updates for the latest ACPI and UEFI specifications. This pull request also includes new 'struct dax_operations' enabling to undo the abuse of copy_user_nocache() for copy operations to pmem. The dax work originally missed 4.12 to address concerns raised by Al. Summary: - Introduce the _flushcache() family of memory copy helpers and use them for persistent memory write operations on x86. The _flushcache() semantic indicates that the cache is either bypassed for the copy operation (movnt) or any lines dirtied by the copy operation are written back (clwb, clflushopt, or clflush). - Extend dax_operations with ->copy_from_iter() and ->flush() operations. These operations and other infrastructure updates allow all persistent memory specific dax functionality to be pushed into libnvdimm and the pmem driver directly. It also allows dax-specific sysfs attributes to be linked to a host device, for example: /sys/block/pmem0/dax/write_cache - Add support for the new NVDIMM platform/firmware mechanisms introduced in ACPI 6.2 and UEFI 2.7. This support includes the v1.2 namespace label format, extensions to the address-range-scrub command set, new error injection commands, and a new BTT (block-translation-table) layout. These updates support inter-OS and pre-OS compatibility. - Fix a longstanding memory corruption bug in nfit_test. - Make the pmem and nvdimm-region 'badblocks' sysfs files poll(2) capable. - Miscellaneous fixes and small updates across libnvdimm and the nfit driver. Acknowledgements that came after the branch was pushed: commit 6aa734a2f38e ("libnvdimm, region, pmem: fix 'badblocks' sysfs_get_dirent() reference lifetime") was reviewed by Toshi Kani <toshi.kani@hpe.com>" * tag 'libnvdimm-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (42 commits) libnvdimm, namespace: record 'lbasize' for pmem namespaces acpi/nfit: Issue Start ARS to retrieve existing records libnvdimm: New ACPI 6.2 DSM functions acpi, nfit: Show bus_dsm_mask in sysfs libnvdimm, acpi, nfit: Add bus level dsm mask for pass thru. acpi, nfit: Enable DSM pass thru for root functions. libnvdimm: passthru functions clear to send libnvdimm, btt: convert some info messages to warn/err libnvdimm, region, pmem: fix 'badblocks' sysfs_get_dirent() reference lifetime libnvdimm: fix the clear-error check in nsio_rw_bytes libnvdimm, btt: fix btt_rw_page not returning errors acpi, nfit: quiet invalid block-aperture-region warnings libnvdimm, btt: BTT updates for UEFI 2.7 format acpi, nfit: constify *_attribute_group libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region libnvdimm, pmem, dax: export a cache control attribute dax: convert to bitmask for flags dax: remove default copy_from_iter fallback libnvdimm, nfit: enable support for volatile ranges libnvdimm, pmem: fix persistence warning ...
2017-07-07mm: per-cgroup memory reclaim statsRoman Gushchin1-1/+1
Track the following reclaim counters for every memory cgroup: PGREFILL, PGSCAN, PGSTEAL, PGACTIVATE, PGDEACTIVATE, PGLAZYFREE and PGLAZYFREED. These values are exposed using the memory.stats interface of cgroup v2. The meaning of each value is the same as for global counters, available using /proc/vmstat. Also, for consistency, rename mem_cgroup_count_vm_event() to count_memcg_event_mm(). Link: http://lkml.kernel.org/r/1494530183-30808-1-git-send-email-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-06dax: set errors in mapping when writeback failsJeff Layton1-1/+3
Jan Kara's description for this patch is much better than mine, so I'm quoting it verbatim here: DAX currently doesn't set errors in the mapping when cache flushing fails in dax_writeback_mapping_range(). Since this function can get called only from fsync(2) or sync(2), this is actually as good as it can currently get since we correctly propagate the error up from dax_writeback_mapping_range() to filemap_fdatawrite() However, in the future better writeback error handling will enable us to properly report these errors on fsync(2) even if there are multiple file descriptors open against the file or if sync(2) gets called before fsync(2). So convert DAX to using standard error reporting through the mapping. Signed-off-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-and-tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
2017-06-28x86, libnvdimm, pmem: remove global pmem apiDan Williams1-1/+0
Now that all callers of the pmem api have been converted to dax helpers that call back to the pmem driver, we can remove include/linux/pmem.h and asm/pmem.h. Cc: <x86@kernel.org> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Oliver O'Halloran <oohall@gmail.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-24Merge branch 'linus' into sched/core, to pick up fixesIngo Molnar1-0/+1
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-24fs/dax.c: fix inefficiency in dax_writeback_mapping_range()Jan Kara1-0/+1
dax_writeback_mapping_range() fails to update iteration index when searching radix tree for entries needing cache flushing. Thus each pagevec worth of entries is searched starting from the start which is inefficient and prone to livelocks. Update index properly. Link: http://lkml.kernel.org/r/20170619124531.21491-1-jack@suse.cz Fixes: 9973c98ecfda3 ("dax: add support for fsync/sync") Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-20sched/wait: Rename wait_queue_t => wait_queue_entry_tIngo Molnar1-2/+2
Rename: wait_queue_t => wait_queue_entry_t 'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue", but in reality it's a queue *entry*. The 'real' queue is the wait queue head, which had to carry the name. Start sorting this out by renaming it to 'wait_queue_entry_t'. This also allows the real structure name 'struct __wait_queue' to lose its double underscore and become 'struct wait_queue_entry', which is the more canonical nomenclature for such data types. Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-06-16x86, dax: replace clear_pmem() with open coded memset + dax_ops->flushDan Williams1-1/+2
The clear_pmem() helper simply combines a memset() plus a cache flush. Now that the flush routine is optionally provided by the dax device driver we can avoid unnecessary cache management on dax devices fronting volatile memory. With clear_pmem() gone we can follow on with a patch to make pmem cache management completely defined within the pmem driver. Cc: <x86@kernel.org> Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-16filesystem-dax: convert to dax_flush()Dan Williams1-1/+1
Filesystem-DAX flushes caches whenever it writes to the address returned through dax_direct_access() and when writing back dirty radix entries. That flushing is only required in the pmem case, so the dax_flush() helper skips cache management work when the underlying driver does not specify a flush method. We still do all the dirty tracking since the radix entry will already be there for locking purposes. However, the work to clean the entry will be a nop for some dax drivers. Cc: Jeff Moyer <jmoyer@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-16filesystem-dax: convert to dax_copy_from_iter()Dan Williams1-1/+2
Now that all possible providers of the dax_operations copy_from_iter method are implemented, switch filesytem-dax to call the driver rather than copy_to_iter_pmem. Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-06-03dax: fix race between colliding PMD & PTE entriesRoss Zwisler1-0/+23
We currently have two related PMD vs PTE races in the DAX code. These can both be easily triggered by having two threads reading and writing simultaneously to the same private mapping, with the key being that private mapping reads can be handled with PMDs but private mapping writes are always handled with PTEs so that we can COW. Here is the first race: CPU 0 CPU 1 (private mapping write) __handle_mm_fault() create_huge_pmd() - FALLBACK handle_pte_fault() passes check for pmd_devmap() (private mapping read) __handle_mm_fault() create_huge_pmd() dax_iomap_pmd_fault() inserts PMD dax_iomap_pte_fault() does a PTE fault, but we already have a DAX PMD installed in our page tables at this spot. Here's the second race: CPU 0 CPU 1 (private mapping read) __handle_mm_fault() passes check for pmd_none() create_huge_pmd() dax_iomap_pmd_fault() inserts PMD (private mapping write) __handle_mm_fault() create_huge_pmd() - FALLBACK (private mapping read) __handle_mm_fault() passes check for pmd_none() create_huge_pmd() handle_pte_fault() dax_iomap_pte_fault() inserts PTE dax_iomap_pmd_fault() inserts PMD, but we already have a PTE at this spot. The core of the issue is that while there is isolation between faults to the same range in the DAX fault handlers via our DAX entry locking, there is no isolation between faults in the code in mm/memory.c. This means for instance that this code in __handle_mm_fault() can run: if (pmd_none(*vmf.pmd) && transparent_hugepage_enabled(vma)) { ret = create_huge_pmd(&vmf); But by the time we actually get to run the fault handler called by create_huge_pmd(), the PMD is no longer pmd_none() because a racing PTE fault has installed a normal PMD here as a parent. This is the cause of the 2nd race. The first race is similar - there is the following check in handle_pte_fault(): } else { /* See comment in pte_alloc_one_map() */ if (pmd_devmap(*vmf->pmd) || pmd_trans_unstable(vmf->pmd)) return 0; So if a pmd_devmap() PMD (a DAX PMD) has been installed at vmf->pmd, we will bail and retry the fault. This is correct, but there is nothing preventing the PMD from being installed after this check but before we actually get to the DAX PTE fault handlers. In my testing these races result in the following types of errors: BUG: Bad rss-counter state mm:ffff8800a817d280 idx:1 val:1 BUG: non-zero nr_ptes on freeing mm: 15 Fix this issue by having the DAX fault handlers verify that it is safe to continue their fault after they have taken an entry lock to block other racing faults. [ross.zwisler@linux.intel.com: improve fix for colliding PMD & PTE entries] Link: http://lkml.kernel.org/r/20170526195932.32178-1-ross.zwisler@linux.intel.com Link: http://lkml.kernel.org/r/20170522215749.23516-2-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by: Pawel Lebioda <pawel.lebioda@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Pawel Lebioda <pawel.lebioda@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Xiong Zhou <xzhou@redhat.com> Cc: Eryu Guan <eguan@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-13Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-60/+31
Merge misc fixes from Andrew Morton: "15 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm, docs: update memory.stat description with workingset* entries mm: vmscan: scan until it finds eligible pages mm, thp: copying user pages must schedule on collapse dax: fix PMD data corruption when fault races with write dax: fix data corruption when fault races with write ext4: return to starting transaction in ext4_dax_huge_fault() mm: fix data corruption due to stale mmap reads dax: prevent invalidation of mapped DAX entries Tigran has moved mm, vmalloc: fix vmalloc users tracking properly mm/khugepaged: add missed tracepoint for collapse_huge_page_swapin gcov: support GCC 7.1 mm, vmstat: Remove spurious WARN() during zoneinfo print time: delete current_fs_time() hwpoison, memcg: forcibly uncharge LRU pages
2017-05-13dax: fix PMD data corruption when fault races with writeRoss Zwisler1-14/+14
This is based on a patch from Jan Kara that fixed the equivalent race in the DAX PTE fault path. Currently DAX PMD read fault can race with write(2) in the following way: CPU1 - write(2) CPU2 - read fault dax_iomap_pmd_fault() ->iomap_begin() - sees hole dax_iomap_rw() iomap_apply() ->iomap_begin - allocates blocks dax_iomap_actor() invalidate_inode_pages2_range() - there's nothing to invalidate grab_mapping_entry() - we add huge zero page to the radix tree and map it to page tables The result is that hole page is mapped into page tables (and thus zeros are seen in mmap) while file has data written in that place. Fix the problem by locking exception entry before mapping blocks for the fault. That way we are sure invalidate_inode_pages2_range() call for racing write will either block on entry lock waiting for the fault to finish (and unmap stale page tables after that) or read fault will see already allocated blocks by write(2). Fixes: 9f141d6ef6258 ("dax: Call ->iomap_begin without entry lock during dax fault") Link: http://lkml.kernel.org/r/20170510172700.18991-1-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-13dax: fix data corruption when fault races with writeJan Kara1-16/+16
Currently DAX read fault can race with write(2) in the following way: CPU1 - write(2) CPU2 - read fault dax_iomap_pte_fault() ->iomap_begin() - sees hole dax_iomap_rw() iomap_apply() ->iomap_begin - allocates blocks dax_iomap_actor() invalidate_inode_pages2_range() - there's nothing to invalidate grab_mapping_entry() - we add zero page in the radix tree and map it to page tables The result is that hole page is mapped into page tables (and thus zeros are seen in mmap) while file has data written in that place. Fix the problem by locking exception entry before mapping blocks for the fault. That way we are sure invalidate_inode_pages2_range() call for racing write will either block on entry lock waiting for the fault to finish (and unmap stale page tables after that) or read fault will see already allocated blocks by write(2). Fixes: 9f141d6ef6258a3a37a045842d9ba7e68f368956 Link: http://lkml.kernel.org/r/20170510085419.27601-5-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-13mm: fix data corruption due to stale mmap readsJan Kara1-1/+1
Currently, we didn't invalidate page tables during invalidate_inode_pages2() for DAX. That could result in e.g. 2MiB zero page being mapped into page tables while there were already underlying blocks allocated and thus data seen through mmap were different from data seen by read(2). The following sequence reproduces the problem: - open an mmap over a 2MiB hole - read from a 2MiB hole, faulting in a 2MiB zero page - write to the hole with write(3p). The write succeeds but we incorrectly leave the 2MiB zero page mapping intact. - via the mmap, read the data that was just written. Since the zero page mapping is still intact we read back zeroes instead of the new data. Fix the problem by unconditionally calling invalidate_inode_pages2_range() in dax_iomap_actor() for new block allocations and by properly invalidating page tables in invalidate_inode_pages2_range() for DAX mappings. Fixes: c6dcf52c23d2d3fb5235cec42d7dd3f786b87d55 Link: http://lkml.kernel.org/r/20170510085419.27601-3-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-13dax: prevent invalidation of mapped DAX entriesRoss Zwisler1-29/+0
Patch series "mm,dax: Fix data corruption due to mmap inconsistency", v4. This series fixes data corruption that can happen for DAX mounts when page faults race with write(2) and as a result page tables get out of sync with block mappings in the filesystem and thus data seen through mmap is different from data seen through read(2). The series passes testing with t_mmap_stale test program from Ross and also other mmap related tests on DAX filesystem. This patch (of 4): dax_invalidate_mapping_entry() currently removes DAX exceptional entries only if they are clean and unlocked. This is done via: invalidate_mapping_pages() invalidate_exceptional_entry() dax_invalidate_mapping_entry() However, for page cache pages removed in invalidate_mapping_pages() there is an additional criteria which is that the page must not be mapped. This is noted in the comments above invalidate_mapping_pages() and is checked in invalidate_inode_page(). For DAX entries this means that we can can end up in a situation where a DAX exceptional entry, either a huge zero page or a regular DAX entry, could end up mapped but without an associated radix tree entry. This is inconsistent with the rest of the DAX code and with what happens in the page cache case. We aren't able to unmap the DAX exceptional entry because according to its comments invalidate_mapping_pages() isn't allowed to block, and unmap_mapping_range() takes a write lock on the mapping->i_mmap_rwsem. Since we essentially never have unmapped DAX entries to evict from the radix tree, just remove dax_invalidate_mapping_entry(). Fixes: c6dcf52c23d2 ("mm: Invalidate DAX radix tree entries only if appropriate") Link: http://lkml.kernel.org/r/20170510085419.27601-2-jack@suse.cz Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Reported-by: Jan Kara <jack@suse.cz> Cc: Dan Williams <dan.j.williams@intel.com> Cc: <stable@vger.kernel.org> [4.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-13Merge branch 'libnvdimm-fixes' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm fixes from Dan Williams: "Incremental fixes and a small feature addition on top of the main libnvdimm 4.12 pull request: - Geert noticed that tinyconfig was bloated by BLOCK selecting DAX. The size regression is fixed by moving all dax helpers into the dax-core and only specifying "select DAX" for FS_DAX and dax-capable drivers. He also asked for clarification of the NR_DEV_DAX config option which, on closer look, does not need to be a config option at all. Mike also throws in a DEV_DAX_PMEM fixup for good measure. - Ben's attention to detail on -stable patch submissions caught a case where the recent fixes to arch_copy_from_iter_pmem() missed a condition where we strand dirty data in the cache. This is tagged for -stable and will also be included in the rework of the pmem api to a proposed {memcpy,copy_user}_flushcache() interface for 4.13. - Vishal adds a feature that missed the initial pull due to pending review feedback. It allows the kernel to clear media errors when initializing a BTT (atomic sector update driver) instance on a pmem namespace. - Ross noticed that the dax_device + dax_operations conversion broke __dax_zero_page_range(). The nvdimm unit tests fail to check this path, but xfstests immediately trips over it. No excuse for missing this before submitting the 4.12 pull request. These all pass the nvdimm unit tests and an xfstests spot check. The set has received a build success notification from the kbuild robot" * 'libnvdimm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: filesystem-dax: fix broken __dax_zero_page_range() conversion libnvdimm, btt: ensure that initializing metadata clears poison libnvdimm: add an atomic vs process context flag to rw_bytes x86, pmem: Fix cache flushing for iovec write < 8 bytes device-dax: kill NR_DEV_DAX block, dax: move "select DAX" from BLOCK to FS_DAX device-dax: Tell kbuild DEV_DAX_PMEM depends on DEV_DAX
2017-05-11filesystem-dax: fix broken __dax_zero_page_range() conversionDan Williams1-2/+2
The conversion of __dax_zero_page_range() to 'struct dax_operations' caused it to frequently fail. The mistake was treating the @size parameter as a dax mapping length rather than just a length of the clear_pmem() operation. The dax mapping length is assumed to be hard coded as PAGE_SIZE. Without this fix any page unaligned zeroing request will trigger a -EINVAL return from bdev_dax_pgoff(). Cc: Jan Kara <jack@suse.com> Cc: Christoph Hellwig <hch@lst.de> Reported-by: Ross Zwisler <ross.zwisler@linux.intel.com> Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com> Fixes: cccbce671582 ("filesystem-dax: convert to dax_direct_access()") Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-05-09dax: add tracepoint to dax_insert_mapping()Ross Zwisler1-0/+1
Add a tracepoint to dax_insert_mapping(), following the same logging conventions as the rest of DAX. This tracepoint, along with the one in dax_load_hole(), lets us know how a DAX PTE fault was serviced. Here is an example DAX fault that inserts a PTE mapping: small-1126 [007] .... 145.451604: dax_pte_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 pgoff 0x220 small-1126 [007] .... 145.452317: dax_insert_mapping: dev 259:0 ino 0x1003 shared write address 0x10420000 radix_entry 0x100006 small-1126 [007] .... 145.452399: dax_pte_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 pgoff 0x220 MAJOR|NOPAGE Link: http://lkml.kernel.org/r/20170221195116.13278-7-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-09dax: add tracepoint to dax_writeback_one()Ross Zwisler1-0/+1
Add a tracepoint to dax_writeback_one(), following the same logging conventions as the rest of DAX. Here is an example range writeback which ends up flushing one PMD and one PTE: test-1265 [003] .... 496.615250: dax_writeback_range: dev 259:0 ino 0x1003 pgoff 0x0-0x7ffffffffffff test-1265 [003] .... 496.616263: dax_writeback_one: dev 259:0 ino 0x1003 pgoff 0x0 pglen 0x200 test-1265 [003] .... 496.616270: dax_writeback_one: dev 259:0 ino 0x1003 pgoff 0x305 pglen 0x1 test-1265 [003] .... 496.616272: dax_writeback_range_done: dev 259:0 ino 0x1003 pgoff 0x0-0x7ffffffffffff [akpm@linux-foundation.org: struct blk_dax_ctl has disappeared] Link: http://lkml.kernel.org/r/20170221195116.13278-6-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-09dax: add tracepoints to dax_writeback_mapping_range()Ross Zwisler1-5/+7
Add tracepoints to dax_writeback_mapping_range(), following the same logging conventions as the rest of DAX. Here is an example writeback call: msync-1085 [006] .... 200.902565: dax_writeback_range: dev 259:0 ino 0x1003 pgoff 0x200-0x2ff msync-1085 [006] .... 200.902579: dax_writeback_range_done: dev 259:0 ino 0x1003 pgoff 0x200-0x2ff [ross.zwisler@linux.intel.com: fix regression in dax_writeback_mapping_range()] Link: http://lkml.kernel.org/r/20170314215358.31451-1-ross.zwisler@linux.intel.com Link: http://lkml.kernel.org/r/20170221195116.13278-5-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-09dax: add tracepoints to dax_load_hole()Ross Zwisler1-5/+11
Add tracepoints to dax_load_hole(), following the same logging conventions as the rest of DAX. Here is the logging generated by a PTE read from a hole: read-1075 [002] .... 62.362108: dax_pte_fault: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10480000 pgoff 0x280 read-1075 [002] .... 62.362140: dax_load_hole: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10480000 pgoff 0x280 NOPAGE read-1075 [002] .... 62.362141: dax_pte_fault_done: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10480000 pgoff 0x280 NOPAGE Link: http://lkml.kernel.org/r/20170221195116.13278-4-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-09dax: add tracepoints to dax_pfn_mkwrite()Ross Zwisler1-0/+3
Add tracepoints to dax_pfn_mkwrite(), following the same logging conventions as the rest of DAX. Here is an example PTE fault followed by a pfn_mkwrite: small_aligned-1094 [002] .... 374.084998: dax_pte_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10400000 pgoff 0x200 small_aligned-1094 [002] .... 374.085145: dax_pte_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10400000 pgoff 0x200 MAJOR|NOPAGE small_aligned-1094 [002] .... 374.085165: dax_pfn_mkwrite: dev 259:0 ino 0x1003 shared WRITE|MKWRITE|ALLOW_RETRY|KILLABLE|USER address 0x10400000 pgoff 0x200 NOPAGE Link: http://lkml.kernel.org/r/20170221195116.13278-3-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-09dax: add tracepoints to dax_iomap_pte_fault()Ross Zwisler1-4/+11
Patch series "second round of tracepoints for DAX". This second round of DAX tracepoint patches adds tracing to the PTE fault path (dax_iomap_pte_fault(), dax_pfn_mkwrite(), dax_load_hole(), dax_insert_mapping()) and to the writeback path (dax_writeback_mapping_range(), dax_writeback_one()). The purpose of this tracing is to give us a high level view of what DAX is doing, whether faults are being serviced by PMDs or PTEs, and by real storage or by zero pages covering holes. I do have some patches nearly ready which also add tracing to grab_mapping_entry() and dax_insert_mapping_entry(). These are more targeted at logging how we are interacting with the radix tree, how we use empty entries for locking, whether we "downgrade" huge zero pages to 4k PTE sized allocations, etc. In the end it seemed to me that this might be too detailed to have as constantly present tracepoints, but if anyone sees value in having tracepoints like this in the DAX code permanently (Jan?), please let me know and I'll add those last two patches. All these tracepoints were done to be consistent with the style of the XFS tracepoints and with the existing DAX PMD tracepoints. This patch (of 6): Add tracepoints to dax_iomap_pte_fault(), following the same logging conventions as the rest of DAX. Here is an example fault that initially tries to be serviced by the PMD fault handler but which falls back to PTEs because the VMA isn't large enough to hold a PMD: small-1086 [005] .... 71.140014: xfs_filemap_huge_fault: dev 259:0 ino 0x1003 small-1086 [005] .... 71.140027: dax_pmd_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 vm_start 0x10200000 vm_end 0x10500000 pgoff 0x220 max_pgoff 0x1400 small-1086 [005] .... 71.140028: dax_pmd_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 vm_start 0x10200000 vm_end 0x10500000 pgoff 0x220 max_pgoff 0x1400 FALLBACK small-1086 [005] .... 71.140035: dax_pte_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 pgoff 0x220 small-1086 [005] .... 71.140396: dax_pte_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10420000 pgoff 0x220 MAJOR|NOPAGE Link: http://lkml.kernel.org/r/20170221195116.13278-2-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-06Merge tag 'libnvdimm-for-4.12' of ↵Linus Torvalds1-141/+156
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The bulk of this has been in multiple -next releases. There were a few late breaking fixes and small features that got added in the last couple days, but the whole set has received a build success notification from the kbuild robot. Change summary: - Region media error reporting: A libnvdimm region device is the parent to one or more namespaces. To date, media errors have been reported via the "badblocks" attribute attached to pmem block devices for namespaces in "raw" or "memory" mode. Given that namespaces can be in "device-dax" or "btt-sector" mode this new interface reports media errors generically, i.e. independent of namespace modes or state. This subsequently allows userspace tooling to craft "ACPI 6.1 Section 9.20.7.6 Function Index 4 - Clear Uncorrectable Error" requests and submit them via the ioctl path for NVDIMM root bus devices. - Introduce 'struct dax_device' and 'struct dax_operations': Prompted by a request from Linus and feedback from Christoph this allows for dax capable drivers to publish their own custom dax operations. This fixes the broken assumption that all dax operations are related to a persistent memory device, and makes it easier for other architectures and platforms to add customized persistent memory support. - 'libnvdimm' core updates: A new "deep_flush" sysfs attribute is available for storage appliance applications to manually trigger memory controllers to drain write-pending buffers that would otherwise be flushed automatically by the platform ADR (asynchronous-DRAM-refresh) mechanism at a power loss event. Support for "locked" DIMMs is included to prevent namespaces from surfacing when the namespace label data area is locked. Finally, fixes for various reported deadlocks and crashes, also tagged for -stable. - ACPI / nfit driver updates: General updates of the nfit driver to add DSM command overrides, ACPI 6.1 health state flags support, DSM payload debug available by default, and various fixes. Acknowledgements that came after the branch was pushed: - commmit 565851c972b5 "device-dax: fix sysfs attribute deadlock": Tested-by: Yi Zhang <yizhan@redhat.com> - commit 23f498448362 "libnvdimm: rework region badblocks clearing" Tested-by: Toshi Kani <toshi.kani@hpe.com>" * tag 'libnvdimm-for-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (52 commits) libnvdimm, pfn: fix 'npfns' vs section alignment libnvdimm: handle locked label storage areas libnvdimm: convert NDD_ flags to use bitops, introduce NDD_LOCKED brd: fix uninitialized use of brd->dax_dev block, dax: use correct format string in bdev_dax_supported device-dax: fix sysfs attribute deadlock libnvdimm: restore "libnvdimm: band aid btt vs clear poison locking" libnvdimm: fix nvdimm_bus_lock() vs device_lock() ordering libnvdimm: rework region badblocks clearing acpi, nfit: kill ACPI_NFIT_DEBUG libnvdimm: fix clear length of nvdimm_forget_poison() libnvdimm, pmem: fix a NULL pointer BUG in nd_pmem_notify libnvdimm, region: sysfs trigger for nvdimm_flush() libnvdimm: fix phys_addr for nvdimm_clear_poison x86, dax, pmem: remove indirection around memcpy_from_pmem() block: remove block_device_operations ->direct_access() block, dax: convert bdev_dax_supported() to dax_direct_access() filesystem-dax: convert to dax_direct_access() Revert "block: use DAX for partition table reads" ext2, ext4, xfs: retrieve dax_device for iomap operations ...
2017-05-01Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-blockLinus Torvalds1-1/+1
Pull block layer updates from Jens Axboe: - Add BFQ IO scheduler under the new blk-mq scheduling framework. BFQ was initially a fork of CFQ, but subsequently changed to implement fairness based on B-WF2Q+, a modified variant of WF2Q. BFQ is meant to be used on desktop type single drives, providing good fairness. From Paolo. - Add Kyber IO scheduler. This is a full multiqueue aware scheduler, using a scalable token based algorithm that throttles IO based on live completion IO stats, similary to blk-wbt. From Omar. - A series from Jan, moving users to separately allocated backing devices. This continues the work of separating backing device life times, solving various problems with hot removal. - A series of updates for lightnvm, mostly from Javier. Includes a 'pblk' target that exposes an open channel SSD as a physical block device. - A series of fixes and improvements for nbd from Josef. - A series from Omar, removing queue sharing between devices on mostly legacy drivers. This helps us clean up other bits, if we know that a queue only has a single device backing. This has been overdue for more than a decade. - Fixes for the blk-stats, and improvements to unify the stats and user windows. This both improves blk-wbt, and enables other users to register a need to receive IO stats for a device. From Omar. - blk-throttle improvements from Shaohua. This provides a scalable framework for implementing scalable priotization - particularly for blk-mq, but applicable to any type of block device. The interface is marked experimental for now. - Bucketized IO stats for IO polling from Stephen Bates. This improves efficiency of polled workloads in the presence of mixed block size IO. - A few fixes for opal, from Scott. - A few pulls for NVMe, including a lot of fixes for NVMe-over-fabrics. From a variety of folks, mostly Sagi and James Smart. - A series from Bart, improving our exposed info and capabilities from the blk-mq debugfs support. - A series from Christoph, cleaning up how handle WRITE_ZEROES. - A series from Christoph, cleaning up the block layer handling of how we track errors in a request. On top of being a nice cleanup, it also shrinks the size of struct request a bit. - Removal of mg_disk and hd (sorry Linus) by Christoph. The former was never used by platforms, and the latter has outlived it's usefulness. - Various little bug fixes and cleanups from a wide variety of folks. * 'for-4.12/block' of git://git.kernel.dk/linux-block: (329 commits) block: hide badblocks attribute by default blk-mq: unify hctx delay_work and run_work block: add kblock_mod_delayed_work_on() blk-mq: unify hctx delayed_run_work and run_work nbd: fix use after free on module unload MAINTAINERS: bfq: Add Paolo as maintainer for the BFQ I/O scheduler blk-mq-sched: alloate reserved tags out of normal pool mtip32xx: use runtime tag to initialize command header scsi: Implement blk_mq_ops.show_rq() blk-mq: Add blk_mq_ops.show_rq() blk-mq: Show operation, cmd_flags and rq_flags names blk-mq: Make blk_flags_show() callers append a newline character blk-mq: Move the "state" debugfs attribute one level down blk-mq: Unregister debugfs attributes earlier blk-mq: Only unregister hctxs for which registration succeeded blk-mq-debugfs: Rename functions for registering and unregistering the mq directory blk-mq: Let blk_mq_debugfs_register() look up the queue name blk-mq: Register <dev>/queue/mq after having registered <dev>/queue ide-pm: always pass 0 error to ide_complete_rq in ide_do_devset ide-pm: always pass 0 error to __blk_end_request_all ..
2017-04-25filesystem-dax: convert to dax_direct_access()Dan Williams1-121/+156
Now that a dax_device is plumbed through all dax-capable drivers we can switch from block_device_operations to dax_operations for invoking ->direct_access. This also lets us kill off some usages of struct blk_dax_ctl on the way to its eventual removal. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-25Revert "block: use DAX for partition table reads"Dan Williams1-20/+0
commit d1a5f2b4d8a1 ("block: use DAX for partition table reads") was part of a stalled effort to allow dax mappings of block devices. Since then the device-dax mechanism has filled the role of dax-mapping static device ranges. Now that we are moving ->direct_access() from a block_device operation to a dax_inode operation we would need block devices to map and carry their own dax_inode reference. Unless / until we decide to revive dax mapping of raw block devices through the dax_inode scheme, there is no need to carry read_dax_sector(). Its removal in turn allows for the removal of bdev_direct_access() and should have been included in commit 223757016837 ("block_dev: remove DAX leftovers"). Cc: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
2017-04-08block: add a flags argument to (__)blkdev_issue_zerooutChristoph Hellwig1-1/+1
Turn the existing discard flag into a new BLKDEV_ZERO_UNMAP flag with similar semantics, but without referring to diѕcard. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-08dax: fix radix tree insertion raceRoss Zwisler1-13/+22
While running generic/340 in my test setup I hit the following race. It can happen with kernels that support FS DAX PMDs, so v4.10 thru v4.11-rc5. Thread 1 Thread 2 -------- -------- dax_iomap_pmd_fault() grab_mapping_entry() spin_lock_irq() get_unlocked_mapping_entry() 'entry' is NULL, can't call lock_slot() spin_unlock_irq() radix_tree_preload() dax_iomap_pmd_fault() grab_mapping_entry() spin_lock_irq() get_unlocked_mapping_entry() ... lock_slot() spin_unlock_irq() dax_pmd_insert_mapping() <inserts a PMD mapping> spin_lock_irq() __radix_tree_insert() fails with -EEXIST <fall back to 4k fault, and die horribly when inserting a 4k entry where a PMD exists> The issue is that we have to drop mapping->tree_lock while calling radix_tree_preload(), but since we didn't have a radix tree entry to lock (unlike in the pmd_downgrade case) we have no protection against Thread 2 coming along and inserting a PMD at the same index. For 4k entries we handled this with a special-case response to -EEXIST coming from the __radix_tree_insert(), but this doesn't save us for PMDs because the -EEXIST case can also mean that we collided with a 4k entry in the radix tree at a different index, but one that is covered by our PMD range. So, correctly handle both the 4k and 2M collision cases by explicitly re-checking the radix tree for an entry at our index once we reacquire mapping->tree_lock. This patch has made it through a clean xfstests run with the current v4.11-rc5 based linux/master, and it also ran generic/340 500 times in a loop. It used to fail within the first 10 iterations. Link: http://lkml.kernel.org/r/20170406212944.2866-1-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: "Darrick J. Wong" <darrick.wong@oracle.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: <stable@vger.kernel.org> [4.10+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-02sched/headers: Prepare for the reduction of <linux/sched.h>'s signal API ↵Ingo Molnar1-0/+1
dependency Instead of including the full <linux/signal.h>, we are going to include the types-only <linux/signal_types.h> header in <linux/sched.h>, to further decouple the scheduler header from the signal headers. This means that various files which relied on the full <linux/signal.h> need to be updated to gain an explicit dependency on it. Update the code that relies on sched.h's inclusion of the <linux/signal.h> header. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-28mm,fs,dax: mark dax_iomap_pmd_fault as constArnd Bergmann1-1/+2
The two alternative implementations of dax_iomap_fault have different prototypes, and one of them is obviously wrong as seen from this build warning: fs/dax.c: In function 'dax_iomap_fault': fs/dax.c:1462:35: error: passing argument 2 of 'dax_iomap_pmd_fault' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers] This marks the argument 'const' as in all the related functions. Fixes: a2d581675d48 ("mm,fs,dax: change ->pmd_fault to ->huge_fault") Link: http://lkml.kernel.org/r/20170227203349.3318733-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-25mm: replace FAULT_FLAG_SIZE with parameter to huge_faultDave Jiang1-4/+5
Since the introduction of FAULT_FLAG_SIZE to the vm_fault flag, it has been somewhat painful with getting the flags set and removed at the correct locations. More than one kernel oops was introduced due to difficulties of getting the placement correctly. Remove the flag values and introduce an input parameter to huge_fault that indicates the size of the page entry. This makes the code easier to trace and should avoid the issues we see with the fault flags where removal of the flag was necessary in the fallback paths. Link: http://lkml.kernel.org/r/148615748258.43180.1690152053774975329.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Tested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-25mm,fs,dax: change ->pmd_fault to ->huge_faultDave Jiang1-13/+32
Patch series "1G transparent hugepage support for device dax", v2. The following series implements support for 1G trasparent hugepage on x86 for device dax. The bulk of the code was written by Mathew Wilcox a while back supporting transparent 1G hugepage for fs DAX. I have forward ported the relevant bits to 4.10-rc. The current submission has only the necessary code to support device DAX. Comments from Dan Williams: So the motivation and intended user of this functionality mirrors the motivation and users of 1GB page support in hugetlbfs. Given expected capacities of persistent memory devices an in-memory database may want to reduce tlb pressure beyond what they can already achieve with 2MB mappings of a device-dax file. We have customer feedback to that effect as Willy mentioned in his previous version of these patches [1]. [1]: https://lkml.org/lkml/2016/1/31/52 Comments from Nilesh @ Oracle: There are applications which have a process model; and if you assume 10,000 processes attempting to mmap all the 6TB memory available on a server; we are looking at the following: processes : 10,000 memory : 6TB pte @ 4k page size: 8 bytes / 4K of memory * #processes = 6TB / 4k * 8 * 10000 = 1.5GB * 80000 = 120,000GB pmd @ 2M page size: 120,000 / 512 = ~240GB pud @ 1G page size: 240GB / 512 = ~480MB As you can see with 2M pages, this system will use up an exorbitant amount of DRAM to hold the page tables; but the 1G pages finally brings it down to a reasonable level. Memory sizes will keep increasing; so this number will keep increasing. An argument can be made to convert the applications from process model to thread model, but in the real world that may not be always practical. Hopefully this helps explain the use case where this is valuable. This patch (of 3): In preparation for adding the ability to handle PUD pages, convert vm_operations_struct.pmd_fault to vm_operations_struct.huge_fault. The vm_fault structure is extended to include a union of the different page table pointers that may be needed, and three flag bits are reserved to indicate which type of pointer is in the union. [ross.zwisler@linux.intel.com: remove unused function ext4_dax_huge_fault()] Link: http://lkml.kernel.org/r/1485813172-7284-1-git-send-email-ross.zwisler@linux.intel.com [dave.jiang@intel.com: clear PMD or PUD size flags when in fall through path] Link: http://lkml.kernel.org/r/148589842696.5820.16078080610311444794.stgit@djiang5-desk3.ch.intel.com Link: http://lkml.kernel.org/r/148545058784.17912.6353162518188733642.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jan Kara <jack@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-25mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmfDave Jiang1-9/+6
->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to take a vma and vmf parameter when the vma already resides in vmf. Remove the vma parameter to simplify things. [arnd@arndb.de: fix ARM build] Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.com> Cc: 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>
2017-02-23Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-46/+58
Merge updates from Andrew Morton: "142 patches: - DAX updates - various misc bits - OCFS2 updates - most of MM" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (142 commits) mm/z3fold.c: limit first_num to the actual range of possible buddy indexes mm: fix <linux/pagemap.h> stray kernel-doc notation zram: remove obsolete sysfs attrs mm/memblock.c: remove unnecessary log and clean up oom-reaper: use madvise_dontneed() logic to decide if unmap the VMA mm: drop unused argument of zap_page_range() mm: drop zap_details::check_swap_entries mm: drop zap_details::ignore_dirty mm, page_alloc: warn_alloc nodemask is NULL when cpusets are disabled mm: help __GFP_NOFAIL allocations which do not trigger OOM killer mm, oom: do not enforce OOM killer for __GFP_NOFAIL automatically mm: consolidate GFP_NOFAIL checks in the allocator slowpath lib/show_mem.c: teach show_mem to work with the given nodemask arch, mm: remove arch specific show_mem mm, page_alloc: warn_alloc print nodemask mm, page_alloc: do not report all nodes in show_mem Revert "mm: bail out in shrink_inactive_list()" mm, vmscan: consider eligible zones in get_scan_count mm, vmscan: cleanup lru size claculations mm, vmscan: do not count freed pages as PGDEACTIVATE ...
2017-02-23Merge tag 'xfs-4.11-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds1-3/+3
Pull xfs updates from Darrick Wong: "Here are the XFS changes for 4.11. We aren't introducing any major features in this release cycle except for this being the first merge window I've managed on my own. :) Changes since last update: - Various cleanups - Livelock fixes for eofblocks scanning - Improved input verification for on-disk metadata - Fix races in the copy on write remap mechanism - Fix buffer io error timeout controls - Streamlining of directio copy on write - Asynchronous discard support - Fix asserts when splitting delalloc reservations - Don't bloat bmbt when right shifting extents - Inode alignment fixes for 32k block sizes" * tag 'xfs-4.11-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (39 commits) xfs: remove XFS_ALLOCTYPE_ANY_AG and XFS_ALLOCTYPE_START_AG xfs: simplify xfs_rtallocate_extent xfs: tune down agno asserts in the bmap code xfs: Use xfs_icluster_size_fsb() to calculate inode chunk alignment xfs: don't reserve blocks for right shift transactions xfs: fix len comparison in xfs_extent_busy_trim xfs: fix uninitialized variable in _reflink_convert_cow xfs: split indlen reservations fairly when under reserved xfs: handle indlen shortage on delalloc extent merge xfs: resurrect debug mode drop buffered writes mechanism xfs: clear delalloc and cache on buffered write failure xfs: don't block the log commit handler for discards xfs: improve busy extent sorting xfs: improve handling of busy extents in the low-level allocator xfs: don't fail xfs_extent_busy allocation xfs: correct null checks and error processing in xfs_initialize_perag xfs: update ctime and mtime on clone destinatation inodes xfs: allocate direct I/O COW blocks in iomap_begin xfs: go straight to real allocations for direct I/O COW writes xfs: return the converted extent in __xfs_reflink_convert_cow ...
2017-02-23mm, dax: change pmd_fault() to take only vmf parameterDave Jiang1-29/+25
pmd_fault() and related functions really only need the vmf parameter since the additional parameters are all included in the vmf struct. Remove the additional parameter and simplify pmd_fault() and friends. Link: http://lkml.kernel.org/r/1484085142-2297-8-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-23mm, dax: make pmd_fault() and friends be the same as fault()Dave Jiang1-17/+11
Instead of passing in multiple parameters in the pmd_fault() handler, a vmf can be passed in just like a fault() handler. This will simplify code and remove the need for the actual pmd fault handlers to allocate a vmf. Related functions are also modified to do the same. [dave.jiang@intel.com: fix issue with xfs_tests stall when DAX option is off] Link: http://lkml.kernel.org/r/148469861071.195597.3619476895250028518.stgit@djiang5-desk3.ch.intel.com Link: http://lkml.kernel.org/r/1484085142-2297-7-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Dave Chinner <david@fromorbit.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-23dax: add tracepoints to dax_pmd_insert_mapping()Ross Zwisler1-3/+9
Add tracepoints to dax_pmd_insert_mapping(), following the same logging conventions as the tracepoints in dax_iomap_pmd_fault(). Here is an example PMD fault showing the new tracepoints: big-1504 [001] .... 326.960743: xfs_filemap_pmd_fault: dev 259:0 ino 0x1003 big-1504 [001] .... 326.960753: dax_pmd_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200 max_pgoff 0x1400 big-1504 [001] .... 326.960981: dax_pmd_insert_mapping: dev 259:0 ino 0x1003 shared write address 0x10505000 length 0x200000 pfn 0x100600 DEV|MAP radix_entry 0xc000e big-1504 [001] .... 326.960986: dax_pmd_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200 max_pgoff 0x1400 NOPAGE Link: http://lkml.kernel.org/r/1484085142-2297-6-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-23dax: add tracepoints to dax_pmd_load_hole()Ross Zwisler1-4/+10
Add tracepoints to dax_pmd_load_hole(), following the same logging conventions as the tracepoints in dax_iomap_pmd_fault(). Here is an example PMD fault showing the new tracepoints: read_big-1478 [004] .... 238.242188: xfs_filemap_pmd_fault: dev 259:0 ino 0x1003 read_big-1478 [004] .... 238.242191: dax_pmd_fault: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10400000 vm_start 0x10200000 vm_end 0x10600000 pgoff 0x200 max_pgoff 0x1400 read_big-1478 [004] .... 238.242390: dax_pmd_load_hole: dev 259:0 ino 0x1003 shared address 0x10400000 zero_page ffffea0002c20000 radix_entry 0x1e read_big-1478 [004] .... 238.242392: dax_pmd_fault_done: dev 259:0 ino 0x1003 shared ALLOW_RETRY|KILLABLE|USER address 0x10400000 vm_start 0x10200000 vm_end 0x10600000 pgoff 0x200 max_pgoff 0x1400 NOPAGE Link: http://lkml.kernel.org/r/1484085142-2297-5-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-23dax: add tracepoint infrastructure, PMD tracingRoss Zwisler1-10/+20
Tracepoints are the standard way to capture debugging and tracing information in many parts of the kernel, including the XFS and ext4 filesystems. Create a tracepoint header for FS DAX and add the first DAX tracepoints to the PMD fault handler. This allows the tracing for DAX to be done in the same way as the filesystem tracing so that developers can look at them together and get a coherent idea of what the system is doing. I added both an entry and exit tracepoint because future patches will add tracepoints to child functions of dax_iomap_pmd_fault() like dax_pmd_load_hole() and dax_pmd_insert_mapping(). We want those messages to be wrapped by the parent function tracepoints so the code flow is more easily understood. Having entry and exit tracepoints for faults also allows us to easily see what filesystems functions were called during the fault. These filesystem functions get executed via iomap_begin() and iomap_end() calls, for example, and will have their own tracepoints. For PMD faults we primarily want to understand the type of mapping, the fault flags, the faulting address and whether it fell back to 4k faults. If it fell back to 4k faults the tracepoints should let us understand why. I named the new tracepoint header file "fs_dax.h" to allow for device DAX to have its own separate tracing header in the same directory at some point. Here is an example output for these events from a successful PMD fault: big-1441 [005] .... 32.582758: xfs_filemap_pmd_fault: dev 259:0 ino 0x1003 big-1441 [005] .... 32.582776: dax_pmd_fault: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200 max_pgoff 0x1400 big-1441 [005] .... 32.583292: dax_pmd_fault_done: dev 259:0 ino 0x1003 shared WRITE|ALLOW_RETRY|KILLABLE|USER address 0x10505000 vm_start 0x10200000 vm_end 0x10700000 pgoff 0x200 max_pgoff 0x1400 NOPAGE Link: http://lkml.kernel.org/r/1484085142-2297-3-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Suggested-by: Dave Chinner <david@fromorbit.com> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-21Merge tag 'ext4_for_linus' of ↵Linus Torvalds1-1/+5
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: "For this cycle we add support for the shutdown ioctl, which is primarily used for testing, but which can be useful on production systems when a scratch volume is being destroyed and the data on it doesn't need to be saved. This found (and we fixed) a number of bugs with ext4's recovery to corrupted file system --- the bugs increased the amount of data that could be potentially lost, and in the case of the inline data feature, could cause the kernel to BUG. Also included are a number of other bug fixes, including in ext4's fscrypt, DAX, inline data support" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (26 commits) ext4: rename EXT4_IOC_GOINGDOWN to EXT4_IOC_SHUTDOWN ext4: fix fencepost in s_first_meta_bg validation ext4: don't BUG when truncating encrypted inodes on the orphan list ext4: do not use stripe_width if it is not set ext4: fix stripe-unaligned allocations dax: assert that i_rwsem is held exclusive for writes ext4: fix DAX write locking ext4: add EXT4_IOC_GOINGDOWN ioctl ext4: add shutdown bit and check for it ext4: rename s_resize_flags to s_ext4_flags ext4: return EROFS if device is r/o and journal replay is needed ext4: preserve the needs_recovery flag when the journal is aborted jbd2: don't leak modified metadata buffers on an aborted journal ext4: fix inline data error paths ext4: move halfmd4 into hash.c directly ext4: fix use-after-iput when fscrypt contexts are inconsistent jbd2: fix use after free in kjournald2() ext4: fix data corruption in data=journal mode ext4: trim allocation requests to group size ext4: replace BUG_ON with WARN_ON in mb_find_extent() ...
2017-02-08dax: assert that i_rwsem is held exclusive for writesChristoph Hellwig1-1/+5
Make sure all callers follow the same locking protocol, given that DAX transparantly replaced the normal buffered I/O path. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Jan Kara <jack@suse.cz>
2017-02-04fs: break out of iomap_file_buffered_write on fatal signalsMichal Hocko1-0/+5
Tetsuo has noticed that an OOM stress test which performs large write requests can cause the full memory reserves depletion. He has tracked this down to the following path __alloc_pages_nodemask+0x436/0x4d0 alloc_pages_current+0x97/0x1b0 __page_cache_alloc+0x15d/0x1a0 mm/filemap.c:728 pagecache_get_page+0x5a/0x2b0 mm/filemap.c:1331 grab_cache_page_write_begin+0x23/0x40 mm/filemap.c:2773 iomap_write_begin+0x50/0xd0 fs/iomap.c:118 iomap_write_actor+0xb5/0x1a0 fs/iomap.c:190 ? iomap_write_end+0x80/0x80 fs/iomap.c:150 iomap_apply+0xb3/0x130 fs/iomap.c:79 iomap_file_buffered_write+0x68/0xa0 fs/iomap.c:243 ? iomap_write_end+0x80/0x80 xfs_file_buffered_aio_write+0x132/0x390 [xfs] ? remove_wait_queue+0x59/0x60 xfs_file_write_iter+0x90/0x130 [xfs] __vfs_write+0xe5/0x140 vfs_write+0xc7/0x1f0 ? syscall_trace_enter+0x1d0/0x380 SyS_write+0x58/0xc0 do_syscall_64+0x6c/0x200 entry_SYSCALL64_slow_path+0x25/0x25 the oom victim has access to all memory reserves to make a forward progress to exit easier. But iomap_file_buffered_write and other callers of iomap_apply loop to complete the full request. We need to check for fatal signals and back off with a short write instead. As the iomap_apply delegates all the work down to the actor we have to hook into those. All callers that work with the page cache are calling iomap_write_begin so we will check for signals there. dax_iomap_actor has to handle the situation explicitly because it copies data to the userspace directly. Other callers like iomap_page_mkwrite work on a single page or iomap_fiemap_actor do not allocate memory based on the given len. Fixes: 68a9f5e7007c ("xfs: implement iomap based buffered write path") Link: http://lkml.kernel.org/r/20170201092706.9966-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-31iomap: constify struct iomap_opsChristoph Hellwig1-3/+3
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-25dax: fix build warnings with FS_DAX and !FS_IOMAPRoss Zwisler1-2/+0
As reported by Arnd: https://lkml.org/lkml/2017/1/10/756 Compiling with the following configuration: # CONFIG_EXT2_FS is not set # CONFIG_EXT4_FS is not set # CONFIG_XFS_FS is not set # CONFIG_FS_IOMAP depends on the above filesystems, as is not set CONFIG_FS_DAX=y generates build warnings about unused functions in fs/dax.c: fs/dax.c:878:12: warning: `dax_insert_mapping' defined but not used [-Wunused-function] static int dax_insert_mapping(struct address_space *mapping, ^~~~~~~~~~~~~~~~~~ fs/dax.c:572:12: warning: `copy_user_dax' defined but not used [-Wunused-function] static int copy_user_dax(struct block_device *bdev, sector_t sector, size_t size, ^~~~~~~~~~~~~ fs/dax.c:542:12: warning: `dax_load_hole' defined but not used [-Wunused-function] static int dax_load_hole(struct address_space *mapping, void **entry, ^~~~~~~~~~~~~ fs/dax.c:312:14: warning: `grab_mapping_entry' defined but not used [-Wunused-function] static void *grab_mapping_entry(struct address_space *mapping, pgoff_t index, ^~~~~~~~~~~~~~~~~~ Now that the struct buffer_head based DAX fault paths and I/O path have been removed we really depend on iomap support being present for DAX. Make this explicit by selecting FS_IOMAP if we compile in DAX support. This allows us to remove conditional selections of FS_IOMAP when FS_DAX was present for ext2 and ext4, and to remove an #ifdef in fs/dax.c. Link: http://lkml.kernel.org/r/1484087383-29478-1-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reported-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-11dax: wrprotect pmd_t in dax_mapping_entry_mkcleanRoss Zwisler1-15/+36
Currently dax_mapping_entry_mkclean() fails to clean and write protect the pmd_t of a DAX PMD entry during an *sync operation. This can result in data loss in the following sequence: 1) mmap write to DAX PMD, dirtying PMD radix tree entry and making the pmd_t dirty and writeable 2) fsync, flushing out PMD data and cleaning the radix tree entry. We currently fail to mark the pmd_t as clean and write protected. 3) more mmap writes to the PMD. These don't cause any page faults since the pmd_t is dirty and writeable. The radix tree entry remains clean. 4) fsync, which fails to flush the dirty PMD data because the radix tree entry was clean. 5) crash - dirty data that should have been fsync'd as part of 4) could still have been in the processor cache, and is lost. Fix this by marking the pmd_t clean and write protected in dax_mapping_entry_mkclean(), which is called as part of the fsync operation 2). This will cause the writes in step 3) above to generate page faults where we'll re-dirty the PMD radix tree entry, resulting in flushes in the fsync that happens in step 4). Fixes: 4b4bb46d00b3 ("dax: clear dirty entry tags on cache flush") Link: http://lkml.kernel.org/r/1482272586-21177-3-git-send-email-ross.zwisler@linux.intel.com Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@lst.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-12-27dax: Call ->iomap_begin without entry lock during dax faultJan Kara1-55/+66
Currently ->iomap_begin() handler is called with entry lock held. If the filesystem held any locks between ->iomap_begin() and ->iomap_end() (such as ext4 which will want to hold transaction open), this would cause lock inversion with the iomap_apply() from standard IO path which first calls ->iomap_begin() and only then calls ->actor() callback which grabs entry locks for DAX (if it faults when copying from/to user provided buffers). Fix the problem by nesting grabbing of entry lock inside ->iomap_begin() - ->iomap_end() pair. Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com>