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2018-01-08iomap: report collisions between directio and buffered writes to userspaceDarrick J. Wong
If two programs simultaneously try to write to the same part of a file via direct IO and buffered IO, there's a chance that the post-diowrite pagecache invalidation will fail on the dirty page. When this happens, the dio write succeeded, which means that the page cache is no longer coherent with the disk! Programs are not supposed to mix IO types and this is a clear case of data corruption, so store an EIO which will be reflected to userspace during the next fsync. Replace the WARN_ON with a ratelimited pr_crit so that the developers have /some/ kind of breadcrumb to track down the offending program(s) and file(s) involved. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
2017-11-14Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull core block layer updates from Jens Axboe: "This is the main pull request for block storage for 4.15-rc1. Nothing out of the ordinary in here, and no API changes or anything like that. Just various new features for drivers, core changes, etc. In particular, this pull request contains: - A patch series from Bart, closing the whole on blk/scsi-mq queue quescing. - A series from Christoph, building towards hidden gendisks (for multipath) and ability to move bio chains around. - NVMe - Support for native multipath for NVMe (Christoph). - Userspace notifications for AENs (Keith). - Command side-effects support (Keith). - SGL support (Chaitanya Kulkarni) - FC fixes and improvements (James Smart) - Lots of fixes and tweaks (Various) - bcache - New maintainer (Michael Lyle) - Writeback control improvements (Michael) - Various fixes (Coly, Elena, Eric, Liang, et al) - lightnvm updates, mostly centered around the pblk interface (Javier, Hans, and Rakesh). - Removal of unused bio/bvec kmap atomic interfaces (me, Christoph) - Writeback series that fix the much discussed hundreds of millions of sync-all units. This goes all the way, as discussed previously (me). - Fix for missing wakeup on writeback timer adjustments (Yafang Shao). - Fix laptop mode on blk-mq (me). - {mq,name} tupple lookup for IO schedulers, allowing us to have alias names. This means you can use 'deadline' on both !mq and on mq (where it's called mq-deadline). (me). - blktrace race fix, oopsing on sg load (me). - blk-mq optimizations (me). - Obscure waitqueue race fix for kyber (Omar). - NBD fixes (Josef). - Disable writeback throttling by default on bfq, like we do on cfq (Luca Miccio). - Series from Ming that enable us to treat flush requests on blk-mq like any other request. This is a really nice cleanup. - Series from Ming that improves merging on blk-mq with schedulers, getting us closer to flipping the switch on scsi-mq again. - BFQ updates (Paolo). - blk-mq atomic flags memory ordering fixes (Peter Z). - Loop cgroup support (Shaohua). - Lots of minor fixes from lots of different folks, both for core and driver code" * 'for-4.15/block' of git://git.kernel.dk/linux-block: (294 commits) nvme: fix visibility of "uuid" ns attribute blk-mq: fixup some comment typos and lengths ide: ide-atapi: fix compile error with defining macro DEBUG blk-mq: improve tag waiting setup for non-shared tags brd: remove unused brd_mutex blk-mq: only run the hardware queue if IO is pending block: avoid null pointer dereference on null disk fs: guard_bio_eod() needs to consider partitions xtensa/simdisk: fix compile error nvme: expose subsys attribute to sysfs nvme: create 'slaves' and 'holders' entries for hidden controllers block: create 'slaves' and 'holders' entries for hidden gendisks nvme: also expose the namespace identification sysfs files for mpath nodes nvme: implement multipath access to nvme subsystems nvme: track shared namespaces nvme: introduce a nvme_ns_ids structure nvme: track subsystems block, nvme: Introduce blk_mq_req_flags_t block, scsi: Make SCSI quiesce and resume work reliably block: Add the QUEUE_FLAG_PREEMPT_ONLY request queue flag ...
2017-11-03block: add a poll_fn callback to struct request_queueChristoph Hellwig
That we we can also poll non blk-mq queues. Mostly needed for the NVMe multipath code, but could also be useful elsewhere. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-25locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland
to READ_ONCE()/WRITE_ONCE() Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-18Merge tag 'xfs-4.14-fixes-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull xfs fixes from Darrick Wong: - fix some more CONFIG_XFS_RT related build problems - fix data loss when writeback at eof races eofblocks gc and loses - invalidate page cache after fs finishes a dio write - remove dirty page state when invalidating pages so releasepage does the right thing when handed a dirty page * tag 'xfs-4.14-fixes-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: move two more RT specific functions into CONFIG_XFS_RT xfs: trim writepage mapping to within eof fs: invalidate page cache after end_io() in dio completion xfs: cancel dirty pages on invalidation
2017-10-18Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "Three small fixes: - A fix for skd, it was using kfree() to free a structure allocate with kmem_cache_alloc(). - Stable fix for nbd, fixing a regression using the normal ioctl based tools. - Fix for a previous fix in this series, that fixed up inconsistencies between buffered and direct IO" * 'for-linus' of git://git.kernel.dk/linux-block: fs: Avoid invalidation in interrupt context in dio_complete() nbd: don't set the device size until we're connected skd: Use kmem_cache_free
2017-10-17fs: Avoid invalidation in interrupt context in dio_complete()Lukas Czerner
Currently we try to defer completion of async DIO to the process context in case there are any mapped pages associated with the inode so that we can invalidate the pages when the IO completes. However the check is racy and the pages can be mapped afterwards. If this happens we might end up calling invalidate_inode_pages2_range() in dio_complete() in interrupt context which could sleep. This can be reproduced by generic/451. Fix this by passing the information whether we can or can't invalidate to the dio_complete(). Thanks Eryu Guan for reporting this and Jan Kara for suggesting a fix. Fixes: 332391a9935d ("fs: Fix page cache inconsistency when mixing buffered and AIO DIO") Reported-by: Eryu Guan <eguan@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: Eryu Guan <eguan@redhat.com> Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-10-16fs: invalidate page cache after end_io() in dio completionEryu Guan
Commit 332391a9935d ("fs: Fix page cache inconsistency when mixing buffered and AIO DIO") moved page cache invalidation from iomap_dio_rw() to iomap_dio_complete() for iomap based direct write path, but before the dio->end_io() call, and it re-introdued the bug fixed by commit c771c14baa33 ("iomap: invalidate page caches should be after iomap_dio_complete() in direct write"). I found this because fstests generic/418 started failing on XFS with v4.14-rc3 kernel, which is the regression test for this specific bug. So similarly, fix it by moving dio->end_io() (which does the unwritten extent conversion) before page cache invalidation, to make sure next buffer read reads the final real allocations not unwritten extents. I also add some comments about why should end_io() go first in case we get it wrong again in the future. Note that, there's no such problem in the non-iomap based direct write path, because we didn't remove the page cache invalidation after the ->direct_IO() in generic_file_direct_write() call, but I decided to fix dio_complete() too so we don't leave a landmine there, also be consistent with iomap_dio_complete(). Fixes: 332391a9935d ("fs: Fix page cache inconsistency when mixing buffered and AIO DIO") Signed-off-by: Eryu Guan <eguan@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Lukas Czerner <lczerner@redhat.com>
2017-10-10direct-io: Prevent NULL pointer access in submit_page_sectionAndreas Gruenbacher
In the code added to function submit_page_section by commit b1058b981, sdio->bio can currently be NULL when calling dio_bio_submit. This then leads to a NULL pointer access in dio_bio_submit, so check for a NULL bio in submit_page_section before trying to submit it instead. Fixes xfstest generic/250 on gfs2. Cc: stable@vger.kernel.org # v3.10+ Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-25fs: Fix page cache inconsistency when mixing buffered and AIO DIOLukas Czerner
Currently when mixing buffered reads and asynchronous direct writes it is possible to end up with the situation where we have stale data in the page cache while the new data is already written to disk. This is permanent until the affected pages are flushed away. Despite the fact that mixing buffered and direct IO is ill-advised it does pose a thread for a data integrity, is unexpected and should be fixed. Fix this by deferring completion of asynchronous direct writes to a process context in the case that there are mapped pages to be found in the inode. Later before the completion in dio_complete() invalidate the pages in question. This ensures that after the completion the pages in the written area are either unmapped, or populated with up-to-date data. Also do the same for the iomap case which uses iomap_dio_complete() instead. This has a side effect of deferring the completion to a process context for every AIO DIO that happens on inode that has pages mapped. However since the consensus is that this is ill-advised practice the performance implication should not be a problem. This was based on proposal from Jeff Moyer, thanks! Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-08-23block: replace bi_bdev with a gendisk pointer and partitions indexChristoph Hellwig
This way we don't need a block_device structure to submit I/O. The block_device has different life time rules from the gendisk and request_queue and is usually only available when the block device node is open. Other callers need to explicitly create one (e.g. the lightnvm passthrough code, or the new nvme multipathing code). For the actual I/O path all that we need is the gendisk, which exists once per block device. But given that the block layer also does partition remapping we additionally need a partition index, which is used for said remapping in generic_make_request. Note that all the block drivers generally want request_queue or sometimes the gendisk, so this removes a layer of indirection all over the stack. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-27fs: add O_DIRECT and aio support for sending down write life time hintsJens Axboe
Reviewed-by: Andreas Dilger <adilger@dilger.ca> Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20block: return on congested block deviceGoldwyn Rodrigues
A new bio operation flag REQ_NOWAIT is introduced to identify bio's orignating from iocb with IOCB_NOWAIT. This flag indicates to return immediately if a request cannot be made instead of retrying. Stacked devices such as md (the ones with make_request_fn hooks) currently are not supported because it may block for housekeeping. For example, an md can have a part of the device suspended. For this reason, only request based devices are supported. In the future, this feature will be expanded to stacked devices by teaching them how to handle the REQ_NOWAIT flags. Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-09block: switch bios to blk_status_tChristoph Hellwig
Replace bi_error with a new bi_status to allow for a clear conversion. Note that device mapper overloaded bi_error with a private value, which we'll have to keep arround at least for now and thus propagate to a proper blk_status_t value. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09fs: simplify dio_bio_completeChristoph Hellwig
Only read bio->bi_error once in the common path. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09fs: remove the unused error argument to dio_end_io()Christoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2017-02-27fs: add i_blocksize()Fabian Frederick
Replace all 1 << inode->i_blkbits and (1 << inode->i_blkbits) in fs branch. This patch also fixes multiple checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' Thanks to Andrew Morton for suggesting more appropriate function instead of macro. [geliangtang@gmail.com: truncate: use i_blocksize()] Link: http://lkml.kernel.org/r/9c8b2cd83c8f5653805d43debde9fa8817e02fc4.1484895804.git.geliangtang@gmail.com Link: http://lkml.kernel.org/r/1481319905-10126-1-git-send-email-fabf@skynet.be Signed-off-by: Fabian Frederick <fabf@skynet.be> Signed-off-by: Geliang Tang <geliangtang@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-10do_direct_IO: Use inode->i_blkbits to compute block count to be cleanedChandan Rajendra
The code currently uses sdio->blkbits to compute the number of blocks to be cleaned. However sdio->blkbits is derived from the logical block size of the underlying block device (Refer to the definition of do_blockdev_direct_IO()). Due to this, generic/299 test would rarely fail when executed on an ext4 filesystem with 64k as the block size and when using a virtio based disk (having 512 byte as the logical block size) inside a kvm guest. This commit fixes the bug by using inode->i_blkbits to compute the number of blocks to be cleaned. Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Fixed up by Jeff Moyer to only use/evaluate inode->i_blkbits once, to avoid issues with block size changes with IO in flight. Signed-off-by: Jens Axboe <axboe@fb.com>
2016-12-14Merge tag 'xfs-for-linus-4.10-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs Pull xfs updates from Dave Chinner: "There is quite a varied bunch of stuff in this update, and some of it you will have already merged through the ext4 tree which imported the dax-4.10-iomap-pmd topic branch from the XFS tree. There is also a new direct IO implementation that uses the iomap infrastructure. It's much simpler, faster, and has lower IO latency than the existing direct IO infrastructure. Summary: - DAX PMD faults via iomap infrastructure - Direct-io support in iomap infrastructure - removal of now-redundant XFS inode iolock, replaced with VFS i_rwsem - synchronisation with fixes and changes in userspace libxfs code - extent tree lookup helpers - lots of little corruption detection improvements to verifiers - optimised CRC calculations - faster buffer cache lookups - deprecation of barrier/nobarrier mount options - we always use REQ_FUA/REQ_FLUSH where appropriate for data integrity now - cleanups to speculative preallocation - miscellaneous minor bug fixes and cleanups" * tag 'xfs-for-linus-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (63 commits) xfs: nuke unused tracepoint definitions xfs: use GPF_NOFS when allocating btree cursors xfs: use xfs_vn_setattr_size to check on new size xfs: deprecate barrier/nobarrier mount option xfs: Always flush caches when integrity is required xfs: ignore leaf attr ichdr.count in verifier during log replay xfs: use rhashtable to track buffer cache xfs: optimise CRC updates xfs: make xfs btree stats less huge xfs: don't cap maximum dedupe request length xfs: don't allow di_size with high bit set xfs: error out if trying to add attrs and anextents > 0 xfs: don't crash if reading a directory results in an unexpected hole xfs: complain if we don't get nextents bmap records xfs: check for bogus values in btree block headers xfs: forbid AG btrees with level == 0 xfs: several xattr functions can be void xfs: handle cow fork in xfs_bmap_trace_exlist xfs: pass state not whichfork to trace_xfs_extlist xfs: Move AGI buffer type setting to xfs_read_agi ...
2016-12-14Merge branch 'for-4.10/fs-unmap' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull fs meta data unmap optimization from Jens Axboe: "A series from Jan Kara, providing a more efficient way for unmapping meta data from in the buffer cache than doing it block-by-block. Provide a general helper that existing callers can use" * 'for-4.10/fs-unmap' of git://git.kernel.dk/linux-block: fs: Remove unmap_underlying_metadata fs: Add helper to clean bdev aliases under a bh and use it ext2: Use clean_bdev_aliases() instead of iteration ext4: Use clean_bdev_aliases() instead of iteration direct-io: Use clean_bdev_aliases() instead of handmade iteration fs: Provide function to unmap metadata for a range of blocks
2016-11-30fs: make sb_init_dio_done_wq available outside of direct-io.cChristoph Hellwig
We want to use the per-sb completion workqueue from the new iomap direct I/O code. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Jens Axboe <axboe@fb.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-11block: move poll code to blk-mqJens Axboe
The poll code is blk-mq specific, let's move it to blk-mq.c. This is a prep patch for improving the polling code. Signed-off-by: Jens Axboe <axboe@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-11-04direct-io: Use clean_bdev_aliases() instead of handmade iterationJan Kara
Use new provided function instead of an iteration through all allocated blocks. Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-11-01block,fs: use REQ_* flags directlyChristoph Hellwig
Remove the WRITE_* and READ_SYNC wrappers, and just use the flags directly. Where applicable this also drops usage of the bio_set_op_attrs wrapper. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-10-03consistent treatment of EFAULT on O_DIRECT read/writeAl Viro
Make local filesystems treat a fault as shortened IO, returning -EFAULT only if nothing had been transferred. That's how everything else (NFS, FUSE, ceph, Lustre) behaves. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-07direct-io: use bio set/get op accessorsMike Christie
This patch has the dio code use a REQ_OP for the op and rq_flag_bits for bi_rw flags. To set/get the op it uses the bio_set_op_attrs/bio_op accssors. It also begins to convert btrfs's dio_submit_t because of the dio submit_io callout use. The next patches will completely convert this code and the reset of the btrfs code paths. Signed-off-by: Mike Christie <mchristi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-06-07block/fs/drivers: remove rw argument from submit_bioMike Christie
This has callers of submit_bio/submit_bio_wait set the bio->bi_rw instead of passing it in. This makes that use the same as generic_make_request and how we set the other bio fields. Signed-off-by: Mike Christie <mchristi@redhat.com> Fixed up fs/ext4/crypto.c Signed-off-by: Jens Axboe <axboe@fb.com>
2016-05-27direct-io: fix direct write stale data exposure from concurrent buffered readEryu Guan
Currently direct writes inside i_size on a DIO_SKIP_HOLES filesystem are not allowed to allocate blocks(get_more_blocks() sets 'create' to 0 before calling get_block() callback), if it's a sparse file, direct writes fall back to buffered writes to avoid stale data exposure from concurrent buffered read. But there're two cases that can result in stale data exposure are not correctly detected. 1. The detection for "writing inside i_size" is not sufficient, writes can be treated as "extending writes" wrongly. For example, direct write 1FSB (file system block) to a 1FSB sparse file on ext2/3/4, starting from offset 0, in this case it's writing inside i_size, but 'create' is non-zero, because 'block_in_file' and '(i_size_read(inode) >> blkbits' are both zero. 2. Direct writes starting from or beyong i_size (not inside i_size) also could trigger block allocation and expose stale data. For example, consider a sparse file with i_size of 2k, and a write to offset 2k or 3k into the file, with a filesystem block size of 4k. (Thanks to Jeff Moyer for pointing this case out in his review.) The first problem can be demostrated by running ltp-aiodio test ADSP045 many times. When testing on extN filesystems, I see test failures occasionally, buffered read could read non-zero (stale) data. ADSP045: dio_sparse -a 4k -w 4k -s 2k -n 1 dio_sparse 0 TINFO : Dirtying free blocks dio_sparse 0 TINFO : Starting I/O tests non zero buffer at buf[0] => 0xffffffaa,ffffffaa,ffffffaa,ffffffaa non-zero read at offset 0 dio_sparse 0 TINFO : Killing childrens(s) dio_sparse 1 TFAIL : dio_sparse.c:191: 1 children(s) exited abnormally The second problem can also be reproduced easily by a hacked dio_sparse program, which accepts an option to specify the write offset. What we should really do is to disable block allocation for writes that could result in filling holes inside i_size. Link: http://lkml.kernel.org/r/1463156728-13357-1-git-send-email-guaneryu@gmail.com Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Eryu Guan <guaneryu@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-01fs: simplify the generic_write_sync prototypeChristoph Hellwig
The kiocb already has the new position, so use that. The only interesting case is AIO, where we currently don't bother updating ki_pos. We're about to free the kiocb after we're done, so we might as well update it to make everyone's life simpler. While we're at it also return the bytes written argument passed in if we were successful so that the boilerplate error switch code in the callers can go away. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01fs: add IOCB_SYNC and IOCB_DSYNCChristoph Hellwig
This will allow us to do per-I/O sync file writes, as required by a lot of fileservers or storage targets. XXX: Will need a few additional audits for O_DSYNC Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01direct-io: remove the offset argument to dio_completeChristoph Hellwig
It has to be identical to ki_pos of the iocb, so use that instead. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01direct-io: eliminate the offset argument to ->direct_IOChristoph Hellwig
Including blkdev_direct_IO and dax_do_io. It has to be ki_pos to actually work, so eliminate the superflous argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-04mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macrosKirill A. Shutemov
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time ago with promise that one day it will be possible to implement page cache with bigger chunks than PAGE_SIZE. This promise never materialized. And unlikely will. We have many places where PAGE_CACHE_SIZE assumed to be equal to PAGE_SIZE. And it's constant source of confusion on whether PAGE_CACHE_* or PAGE_* constant should be used in a particular case, especially on the border between fs and mm. Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much breakage to be doable. Let's stop pretending that pages in page cache are special. They are not. The changes are pretty straight-forward: - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>; - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN}; - page_cache_get() -> get_page(); - page_cache_release() -> put_page(); This patch contains automated changes generated with coccinelle using script below. For some reason, coccinelle doesn't patch header files. I've called spatch for them manually. The only adjustment after coccinelle is revert of changes to PAGE_CAHCE_ALIGN definition: we are going to drop it later. There are few places in the code where coccinelle didn't reach. I'll fix them manually in a separate patch. Comments and documentation also will be addressed with the separate patch. virtual patch @@ expression E; @@ - E << (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ expression E; @@ - E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) + E @@ @@ - PAGE_CACHE_SHIFT + PAGE_SHIFT @@ @@ - PAGE_CACHE_SIZE + PAGE_SIZE @@ @@ - PAGE_CACHE_MASK + PAGE_MASK @@ expression E; @@ - PAGE_CACHE_ALIGN(E) + PAGE_ALIGN(E) @@ expression E; @@ - page_cache_get(E) + get_page(E) @@ expression E; @@ - page_cache_release(E) + put_page(E) Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-21Merge tag 'xfs-for-linus-4.6-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs Pull xfs updates from Dave Chinner: "There's quite a lot in this request, and there's some cross-over with ext4, dax and quota code due to the nature of the changes being made. As for the rest of the XFS changes, there are lots of little things all over the place, which add up to a lot of changes in the end. The major changes are that we've reduced the size of the struct xfs_inode by ~100 bytes (gives an inode cache footprint reduction of >10%), the writepage code now only does a single set of mapping tree lockups so uses less CPU, delayed allocation reservations won't overrun under random write loads anymore, and we added compile time verification for on-disk structure sizes so we find out when a commit or platform/compiler change breaks the on disk structure as early as possible. Change summary: - error propagation for direct IO failures fixes for both XFS and ext4 - new quota interfaces and XFS implementation for iterating all the quota IDs in the filesystem - locking fixes for real-time device extent allocation - reduction of duplicate information in the xfs and vfs inode, saving roughly 100 bytes of memory per cached inode. - buffer flag cleanup - rework of the writepage code to use the generic write clustering mechanisms - several fixes for inode flag based DAX enablement - rework of remount option parsing - compile time verification of on-disk format structure sizes - delayed allocation reservation overrun fixes - lots of little error handling fixes - small memory leak fixes - enable xfsaild freezing again" * tag 'xfs-for-linus-4.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (66 commits) xfs: always set rvalp in xfs_dir2_node_trim_free xfs: ensure committed is initialized in xfs_trans_roll xfs: borrow indirect blocks from freed extent when available xfs: refactor delalloc indlen reservation split into helper xfs: update freeblocks counter after extent deletion xfs: debug mode forced buffered write failure xfs: remove impossible condition xfs: check sizes of XFS on-disk structures at compile time xfs: ioends require logically contiguous file offsets xfs: use named array initializers for log item dumping xfs: fix computation of inode btree maxlevels xfs: reinitialise per-AG structures if geometry changes during recovery xfs: remove xfs_trans_get_block_res xfs: fix up inode32/64 (re)mount handling xfs: fix format specifier , should be %llx and not %llu xfs: sanitize remount options xfs: convert mount option parsing to tokens xfs: fix two memory leaks in xfs_attr_list.c error paths xfs: XFS_DIFLAG2_DAX limited by PAGE_SIZE xfs: dynamically switch modes when XFS_DIFLAG2_DAX is set/cleared ...
2016-03-19Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: - Preparations of parallel lookups (the remaining main obstacle is the need to move security_d_instantiate(); once that becomes safe, the rest will be a matter of rather short series local to fs/*.c - preadv2/pwritev2 series from Christoph - assorted fixes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (32 commits) splice: handle zero nr_pages in splice_to_pipe() vfs: show_vfsstat: do not ignore errors from show_devname method dcache.c: new helper: __d_add() don't bother with __d_instantiate(dentry, NULL) untangle fsnotify_d_instantiate() a bit uninline d_add() replace d_add_unique() with saner primitive quota: use lookup_one_len_unlocked() cifs_get_root(): use lookup_one_len_unlocked() nfs_lookup: don't bother with d_instantiate(dentry, NULL) kill dentry_unhash() ceph_fill_trace(): don't bother with d_instantiate(dn, NULL) autofs4: don't bother with d_instantiate(dentry, NULL) in ->lookup() configfs: move d_rehash() into configfs_create() for regular files ceph: don't bother with d_rehash() in splice_dentry() namei: teach lookup_slow() to skip revalidate namei: massage lookup_slow() to be usable by lookup_one_len_unlocked() lookup_one_len_unlocked(): use lookup_dcache() namei: simplify invalidation logics in lookup_dcache() namei: change calling conventions for lookup_{fast,slow} and follow_managed() ...
2016-03-04direct-io: only use block polling if explicitly requestedChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Stephen Bates <stephen.bates@pmcs.com> Tested-by: Stephen Bates <stephen.bates@pmcs.com> Acked-by: Jeff Moyer <jmoyer@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-02-08direct-io: always call ->end_io if non-NULLChristoph Hellwig
This way we can pass back errors to the file system, and allow for cleanup required for all direct I/O invocations. Also allow the ->end_io handlers to return errors on their own, so that I/O completion errors can be passed on to the callers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-30block: fix use-after-free in dio_bio_completeMike Krinkin
kasan reported the following error when i ran xfstest: [ 701.826854] ================================================================== [ 701.826864] BUG: KASAN: use-after-free in dio_bio_complete+0x41a/0x600 at addr ffff880080b95f94 [ 701.826870] Read of size 4 by task loop2/3874 [ 701.826879] page:ffffea000202e540 count:0 mapcount:0 mapping: (null) index:0x0 [ 701.826890] flags: 0x100000000000000() [ 701.826895] page dumped because: kasan: bad access detected [ 701.826904] CPU: 3 PID: 3874 Comm: loop2 Tainted: G B W L 4.5.0-rc1-next-20160129 #83 [ 701.826910] Hardware name: LENOVO 23205NG/23205NG, BIOS G2ET95WW (2.55 ) 07/09/2013 [ 701.826917] ffff88008fadf800 ffff88008fadf758 ffffffff81ca67bb 0000000041b58ab3 [ 701.826941] ffffffff830d1e74 ffffffff81ca6724 ffff88008fadf748 ffffffff8161c05c [ 701.826963] 0000000000000282 ffff88008fadf800 ffffed0010172bf2 ffffea000202e540 [ 701.826987] Call Trace: [ 701.826997] [<ffffffff81ca67bb>] dump_stack+0x97/0xdc [ 701.827005] [<ffffffff81ca6724>] ? _atomic_dec_and_lock+0xc4/0xc4 [ 701.827014] [<ffffffff8161c05c>] ? __dump_page+0x32c/0x490 [ 701.827023] [<ffffffff816b0d03>] kasan_report_error+0x5f3/0x8b0 [ 701.827033] [<ffffffff817c302a>] ? dio_bio_complete+0x41a/0x600 [ 701.827040] [<ffffffff816b1119>] __asan_report_load4_noabort+0x59/0x80 [ 701.827048] [<ffffffff817c302a>] ? dio_bio_complete+0x41a/0x600 [ 701.827053] [<ffffffff817c302a>] dio_bio_complete+0x41a/0x600 [ 701.827057] [<ffffffff81bd19c8>] ? blk_queue_exit+0x108/0x270 [ 701.827060] [<ffffffff817c32b0>] dio_bio_end_aio+0xa0/0x4d0 [ 701.827063] [<ffffffff817c3210>] ? dio_bio_complete+0x600/0x600 [ 701.827067] [<ffffffff81bd2806>] ? blk_account_io_completion+0x316/0x5d0 [ 701.827070] [<ffffffff81bafe89>] bio_endio+0x79/0x200 [ 701.827074] [<ffffffff81bd2c9f>] blk_update_request+0x1df/0xc50 [ 701.827078] [<ffffffff81c02c27>] blk_mq_end_request+0x57/0x120 [ 701.827081] [<ffffffff81c03670>] __blk_mq_complete_request+0x310/0x590 [ 701.827084] [<ffffffff812348d8>] ? set_next_entity+0x2f8/0x2ed0 [ 701.827088] [<ffffffff8124b34d>] ? put_prev_entity+0x22d/0x2a70 [ 701.827091] [<ffffffff81c0394b>] blk_mq_complete_request+0x5b/0x80 [ 701.827094] [<ffffffff821e2a33>] loop_queue_work+0x273/0x19d0 [ 701.827098] [<ffffffff811f6578>] ? finish_task_switch+0x1c8/0x8e0 [ 701.827101] [<ffffffff8129d058>] ? trace_hardirqs_on_caller+0x18/0x6c0 [ 701.827104] [<ffffffff821e27c0>] ? lo_read_simple+0x890/0x890 [ 701.827108] [<ffffffff8129dd60>] ? debug_check_no_locks_freed+0x350/0x350 [ 701.827111] [<ffffffff811f63b0>] ? __hrtick_start+0x130/0x130 [ 701.827115] [<ffffffff82a0c8f6>] ? __schedule+0x936/0x20b0 [ 701.827118] [<ffffffff811dd6bd>] ? kthread_worker_fn+0x3ed/0x8d0 [ 701.827121] [<ffffffff811dd4ed>] ? kthread_worker_fn+0x21d/0x8d0 [ 701.827125] [<ffffffff8129d058>] ? trace_hardirqs_on_caller+0x18/0x6c0 [ 701.827128] [<ffffffff811dd57f>] kthread_worker_fn+0x2af/0x8d0 [ 701.827132] [<ffffffff811dd2d0>] ? __init_kthread_worker+0x170/0x170 [ 701.827135] [<ffffffff82a1ea46>] ? _raw_spin_unlock_irqrestore+0x36/0x60 [ 701.827138] [<ffffffff811dd2d0>] ? __init_kthread_worker+0x170/0x170 [ 701.827141] [<ffffffff811dd2d0>] ? __init_kthread_worker+0x170/0x170 [ 701.827144] [<ffffffff811dd00b>] kthread+0x24b/0x3a0 [ 701.827148] [<ffffffff811dcdc0>] ? kthread_create_on_node+0x4c0/0x4c0 [ 701.827151] [<ffffffff8129d70d>] ? trace_hardirqs_on+0xd/0x10 [ 701.827155] [<ffffffff8116d41d>] ? do_group_exit+0xdd/0x350 [ 701.827158] [<ffffffff811dcdc0>] ? kthread_create_on_node+0x4c0/0x4c0 [ 701.827161] [<ffffffff82a1f52f>] ret_from_fork+0x3f/0x70 [ 701.827165] [<ffffffff811dcdc0>] ? kthread_create_on_node+0x4c0/0x4c0 [ 701.827167] Memory state around the buggy address: [ 701.827170] ffff880080b95e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 701.827172] ffff880080b95f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 701.827175] >ffff880080b95f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 701.827177] ^ [ 701.827179] ffff880080b96000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 701.827182] ffff880080b96080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff [ 701.827183] ================================================================== The problem is that bio_check_pages_dirty calls bio_put, so we must not access bio fields after bio_check_pages_dirty. Fixes: 9b81c842355ac96097ba ("block: don't access bio->bi_error after bio_put()"). Signed-off-by: Mike Krinkin <krinkin.m.u@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@fb.com>
2016-01-22wrappers for ->i_mutex accessAl Viro
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-08fix the regression from "direct-io: Fix negative return from dio read beyond ↵Al Viro
eof" Sure, it's better to bail out of past-the-eof read and return 0 than return a bogus negative value on such. Only we'd better make sure we are bailing out with 0 and not -ENOMEM... Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-30direct-io: Fix negative return from dio read beyond eofJan Kara
Assume a filesystem with 4KB blocks. When a file has size 1000 bytes and we issue direct IO read at offset 1024, blockdev_direct_IO() reads the tail of the last block and the logic for handling short DIO reads in dio_complete() results in a return value -24 (1000 - 1024) which obviously confuses userspace. Fix the problem by bailing out early once we sample i_size and can reliably check that direct IO read starts beyond i_size. Reported-by: Avi Kivity <avi@scylladb.com> Fixes: 9fe55eea7e4b444bafc42fa0000cc2d1d2847275 CC: stable@vger.kernel.org CC: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-10Merge branch 'for-4.4/io-poll' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block IO poll support from Jens Axboe: "Various groups have been doing experimentation around IO polling for (really) fast devices. The code has been reviewed and has been sitting on the side for a few releases, but this is now good enough for coordinated benchmarking and further experimentation. Currently O_DIRECT sync read/write are supported. A framework is in the works that allows scalable stats tracking so we can auto-tune this. And we'll add libaio support as well soon. Fow now, it's an opt-in feature for test purposes" * 'for-4.4/io-poll' of git://git.kernel.dk/linux-block: direct-io: be sure to assign dio->bio_bdev for both paths directio: add block polling support NVMe: add blk polling support block: add block polling support blk-mq: return tag/queue combo in the make_request_fn handlers block: change ->make_request_fn() and users to return a queue cookie
2015-11-10direct-io: be sure to assign dio->bio_bdev for both pathsJens Axboe
btrfs sets ->submit_io(), and we failed to set the block dev for that path. That resulted in a potential NULL dereference when we later wait for IO in dio_await_one(). Reported-by: kernel test robot <ying.huang@linux.intel.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-11-07directio: add block polling supportJens Axboe
This adds support for sync O_DIRECT read/write poll support. Signed-off-by: Jens Axboe <axboe@fb.com> [hch: split from a larger patch, minor updates] Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Keith Busch <keith.busch@intel.com>
2015-11-06mm, page_alloc: rename __GFP_WAIT to __GFP_RECLAIMMel Gorman
__GFP_WAIT was used to signal that the caller was in atomic context and could not sleep. Now it is possible to distinguish between true atomic context and callers that are not willing to sleep. The latter should clear __GFP_DIRECT_RECLAIM so kswapd will still wake. As clearing __GFP_WAIT behaves differently, there is a risk that people will clear the wrong flags. This patch renames __GFP_WAIT to __GFP_RECLAIM to clearly indicate what it does -- setting it allows all reclaim activity, clearing them prevents it. [akpm@linux-foundation.org: fix build] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Christoph Lameter <cl@linux.com> Acked-by: David Rientjes <rientjes@google.com> Cc: Vitaly Wool <vitalywool@gmail.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-23fs: direct-io: don't dirtying pages for ITER_BVEC/ITER_KVEC direct readMing Lei
When direct read IO is submitted from kernel, it is often unnecessary to dirty pages, for example of loop, dirtying pages have been considered in the upper filesystem(over loop) side already, and they don't need to be dirtied again. So this patch doesn't dirtying pages for ITER_BVEC/ITER_KVEC direct read, and loop should be the 1st case to use ITER_BVEC/ITER_KVEC for direct read I/O. The patch is based on previous Dave's patch. Reviewed-by: Dave Kleikamp <dave.kleikamp@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-13block: remove bio_get_nr_vecs()Kent Overstreet
We can always fill up the bio now, no need to estimate the possible size based on queue parameters. Acked-by: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> [hch: rebased and wrote a changelog] Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lin <ming.l@ssi.samsung.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-08-11block: don't access bio->bi_error after bio_put()Sasha Levin
Commit 4246a0b6 ("block: add a bi_error field to struct bio") has added a few dereferences of 'bio' after a call to bio_put(). This causes use-after-frees such as: [521120.719695] BUG: KASan: use after free in dio_bio_complete+0x2b3/0x320 at addr ffff880f36b38714 [521120.720638] Read of size 4 by task mount.ocfs2/9644 [521120.721212] ============================================================================= [521120.722056] BUG kmalloc-256 (Not tainted): kasan: bad access detected [521120.722968] ----------------------------------------------------------------------------- [521120.722968] [521120.723915] Disabling lock debugging due to kernel taint [521120.724539] INFO: Slab 0xffffea003cdace00 objects=32 used=25 fp=0xffff880f36b38600 flags=0x46fffff80004080 [521120.726037] INFO: Object 0xffff880f36b38700 @offset=1792 fp=0xffff880f36b38800 [521120.726037] [521120.726974] Bytes b4 ffff880f36b386f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.727898] Object ffff880f36b38700: 00 88 b3 36 0f 88 ff ff 00 00 d8 de 0b 88 ff ff ...6............ [521120.728822] Object ffff880f36b38710: 02 00 00 f0 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.729705] Object ffff880f36b38720: 01 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 ................ [521120.730623] Object ffff880f36b38730: 00 00 00 00 00 00 00 00 01 00 00 00 00 02 00 00 ................ [521120.731621] Object ffff880f36b38740: 00 02 00 00 01 00 00 00 d0 f7 87 ad ff ff ff ff ................ [521120.732776] Object ffff880f36b38750: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.733640] Object ffff880f36b38760: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.734508] Object ffff880f36b38770: 01 00 03 00 01 00 00 00 88 87 b3 36 0f 88 ff ff ...........6.... [521120.735385] Object ffff880f36b38780: 00 73 22 ad 02 88 ff ff 40 13 e0 3c 00 ea ff ff .s".....@..<.... [521120.736667] Object ffff880f36b38790: 00 02 00 00 00 04 00 00 00 00 00 00 00 00 00 00 ................ [521120.737596] Object ffff880f36b387a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.738524] Object ffff880f36b387b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.739388] Object ffff880f36b387c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.740277] Object ffff880f36b387d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.741187] Object ffff880f36b387e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.742233] Object ffff880f36b387f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ [521120.743229] CPU: 41 PID: 9644 Comm: mount.ocfs2 Tainted: G B 4.2.0-rc6-next-20150810-sasha-00039-gf909086 #2420 [521120.744274] ffff880f36b38000 ffff880d89c8f638 ffffffffb6e9ba8a ffff880101c0e5c0 [521120.745025] ffff880d89c8f668 ffffffffad76a313 ffff880101c0e5c0 ffffea003cdace00 [521120.745908] ffff880f36b38700 ffff880f36b38798 ffff880d89c8f690 ffffffffad772854 [521120.747063] Call Trace: [521120.747520] dump_stack (lib/dump_stack.c:52) [521120.748053] print_trailer (mm/slub.c:653) [521120.748582] object_err (mm/slub.c:660) [521120.749079] kasan_report_error (include/linux/kasan.h:20 mm/kasan/report.c:152 mm/kasan/report.c:194) [521120.750834] __asan_report_load4_noabort (mm/kasan/report.c:250) [521120.753580] dio_bio_complete (fs/direct-io.c:478) [521120.755752] do_blockdev_direct_IO (fs/direct-io.c:494 fs/direct-io.c:1291) [521120.759765] __blockdev_direct_IO (fs/direct-io.c:1322) [521120.761658] blkdev_direct_IO (fs/block_dev.c:162) [521120.762993] generic_file_read_iter (mm/filemap.c:1738) [521120.767405] blkdev_read_iter (fs/block_dev.c:1649) [521120.768556] __vfs_read (fs/read_write.c:423 fs/read_write.c:434) [521120.772126] vfs_read (fs/read_write.c:454) [521120.773118] SyS_pread64 (fs/read_write.c:607 fs/read_write.c:594) [521120.776062] entry_SYSCALL_64_fastpath (arch/x86/entry/entry_64.S:186) [521120.777375] Memory state around the buggy address: [521120.778118] ffff880f36b38600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [521120.779211] ffff880f36b38680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [521120.780315] >ffff880f36b38700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [521120.781465] ^ [521120.782083] ffff880f36b38780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [521120.783717] ffff880f36b38800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [521120.784818] ================================================================== This patch fixes a few of those places that I caught while auditing the patch, but the original patch should be audited further for more occurences of this issue since I'm not too familiar with the code. Signed-off-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-07-29block: add a bi_error field to struct bioChristoph Hellwig
Currently we have two different ways to signal an I/O error on a BIO: (1) by clearing the BIO_UPTODATE flag (2) by returning a Linux errno value to the bi_end_io callback The first one has the drawback of only communicating a single possible error (-EIO), and the second one has the drawback of not beeing persistent when bios are queued up, and are not passed along from child to parent bio in the ever more popular chaining scenario. Having both mechanisms available has the additional drawback of utterly confusing driver authors and introducing bugs where various I/O submitters only deal with one of them, and the others have to add boilerplate code to deal with both kinds of error returns. So add a new bi_error field to store an errno value directly in struct bio and remove the existing mechanisms to clean all this up. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: NeilBrown <neilb@suse.com> Signed-off-by: Jens Axboe <axboe@fb.com>
2015-04-24direct-io: only inc/dec inode->i_dio_count for file systemsJens Axboe
do_blockdev_direct_IO() increments and decrements the inode ->i_dio_count for each IO operation. It does this to protect against truncate of a file. Block devices don't need this sort of protection. For a capable multiqueue setup, this atomic int is the only shared state between applications accessing the device for O_DIRECT, and it presents a scaling wall for that. In my testing, as much as 30% of system time is spent incrementing and decrementing this value. A mixed read/write workload improved from ~2.5M IOPS to ~9.6M IOPS, with better latencies too. Before: clat percentiles (usec): | 1.00th=[ 33], 5.00th=[ 34], 10.00th=[ 34], 20.00th=[ 34], | 30.00th=[ 34], 40.00th=[ 34], 50.00th=[ 35], 60.00th=[ 35], | 70.00th=[ 35], 80.00th=[ 35], 90.00th=[ 37], 95.00th=[ 80], | 99.00th=[ 98], 99.50th=[ 151], 99.90th=[ 155], 99.95th=[ 155], | 99.99th=[ 165] After: clat percentiles (usec): | 1.00th=[ 95], 5.00th=[ 108], 10.00th=[ 129], 20.00th=[ 149], | 30.00th=[ 155], 40.00th=[ 161], 50.00th=[ 167], 60.00th=[ 171], | 70.00th=[ 177], 80.00th=[ 185], 90.00th=[ 201], 95.00th=[ 270], | 99.00th=[ 390], 99.50th=[ 398], 99.90th=[ 418], 99.95th=[ 422], | 99.99th=[ 438] In other setups, Robert Elliott reported seeing good performance improvements: https://lkml.org/lkml/2015/4/3/557 The more applications accessing the device, the worse it gets. Add a new direct-io flags, DIO_SKIP_DIO_COUNT, which tells do_blockdev_direct_IO() that it need not worry about incrementing or decrementing the inode i_dio_count for this caller. Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Hellwig <hch@lst.de> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Elliott, Robert (Server Storage) <elliott@hp.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jens Axboe <axboe@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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