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* block: pass a block_device and opf to bio_allocChristoph Hellwig2022-02-021-4/+1
| | | | | | | | | | | | | | | Pass the block_device and operation that we plan to use this bio for to bio_alloc to optimize the assignment. NULL/0 can be passed, both for the passthrough case on a raw request_queue and to temporarily avoid refactoring some nasty code. Also move the gfp_mask argument after the nr_vecs argument for a much more logical calling convention matching what most of the kernel does. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Link: https://lore.kernel.org/r/20220124091107.642561-18-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
* fs: get rid of the res2 iocb->ki_complete argumentJens Axboe2021-10-251-1/+1
| | | | | | | | | | | The second argument was only used by the USB gadget code, yet everyone pays the overhead of passing a zero to be passed into aio, where it ends up being part of the aio res2 value. Now that everybody is passing in zero, kill off the extra argument. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* direct-io: remove blk_poll supportChristoph Hellwig2021-10-181-10/+4
| | | | | | | | | | | | | The polling support in the legacy direct-io support is a little crufty. It already doesn't support the asynchronous polling needed for io_uring polling, and is hard to adopt to upcoming changes in the polling interfaces. Given that all the major file systems already use the iomap direct I/O code, just drop the polling support. Signed-off-by: Christoph Hellwig <hch@lst.de> Tested-by: Mark Wunderlich <mark.wunderlich@intel.com> Link: https://lore.kernel.org/r/20211012111226.760968-2-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
* fs: direct-io: fix missing sdio->boundaryJack Qiu2021-04-091-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | I encountered a hung task issue, but not a performance one. I run DIO on a device (need lba continuous, for example open channel ssd), maybe hungtask in below case: DIO: Checkpoint: get addr A(at boundary), merge into BIO, no submit because boundary missing flush dirty data(get addr A+1), wait IO(A+1) writeback timeout, because DIO(A) didn't submit get addr A+2 fail, because checkpoint is doing dio_send_cur_page() may clear sdio->boundary, so prevent it from missing a boundary. Link: https://lkml.kernel.org/r/20210322042253.38312-1-jack.qiu@huawei.com Fixes: b1058b981272 ("direct-io: submit bio after boundary buffer is added to it") Signed-off-by: Jack Qiu <jack.qiu@huawei.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'block-5.12-2021-02-27' of git://git.kernel.dk/linux-blockLinus Torvalds2021-02-281-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull more block updates from Jens Axboe: "A few stragglers (and one due to me missing it originally), and fixes for changes in this merge window mostly. In particular: - blktrace cleanups (Chaitanya, Greg) - Kill dead blk_pm_* functions (Bart) - Fixes for the bio alloc changes (Christoph) - Fix for the partition changes (Christoph, Ming) - Fix for turning off iopoll with polled IO inflight (Jeffle) - nbd disconnect fix (Josef) - loop fsync error fix (Mauricio) - kyber update depth fix (Yang) - max_sectors alignment fix (Mikulas) - Add bio_max_segs helper (Matthew)" * tag 'block-5.12-2021-02-27' of git://git.kernel.dk/linux-block: (21 commits) block: Add bio_max_segs blktrace: fix documentation for blk_fill_rw() block: memory allocations in bounce_clone_bio must not fail block: remove the gfp_mask argument to bounce_clone_bio block: fix bounce_clone_bio for passthrough bios block-crypto-fallback: use a bio_set for splitting bios block: fix logging on capacity change blk-settings: align max_sectors on "logical_block_size" boundary block: reopen the device in blkdev_reread_part block: don't skip empty device in in disk_uevent blktrace: remove debugfs file dentries from struct blk_trace nbd: handle device refs for DESTROY_ON_DISCONNECT properly kyber: introduce kyber_depth_updated() loop: fix I/O error on fsync() in detached loop devices block: fix potential IO hang when turning off io_poll block: get rid of the trace rq insert wrapper blktrace: fix blk_rq_merge documentation blktrace: fix blk_rq_issue documentation blktrace: add blk_fill_rwbs documentation comment block: remove superfluous param in blk_fill_rwbs() ...
| * block: Add bio_max_segsMatthew Wilcox (Oracle)2021-02-261-1/+1
| | | | | | | | | | | | | | | | | | | | It's often inconvenient to use BIO_MAX_PAGES due to min() requiring the sign to be the same. Introduce bio_max_segs() and change BIO_MAX_PAGES to be unsigned to make it easier for the users. Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | fs: delete repeated words in commentsRandy Dunlap2021-02-241-2/+2
|/ | | | | | | | | | | | | Delete duplicate words in fs/*.c. The doubled words that are being dropped are: that, be, the, in, and, for Link: https://lkml.kernel.org/r/20201224052810.25315-1-rdunlap@infradead.org Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* block/psi: remove PSI annotations from direct IOPavel Begunkov2021-01-251-0/+2
| | | | | | | | | | | | | | | | | | | | Direct IO does not operate on the current working set of pages managed by the kernel, so it should not be accounted as memory stall to PSI infrastructure. The block layer and iomap direct IO use bio_iov_iter_get_pages() to build bios, and they are the only users of it, so to avoid PSI tracking for them clear out BIO_WORKINGSET flag. Do same for dio_bio_submit() because fs/direct_io constructs bios by hand directly calling bio_add_page(). Reported-by: Christoph Hellwig <hch@infradead.org> Suggested-by: Christoph Hellwig <hch@infradead.org> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: store a block_device pointer in struct bioChristoph Hellwig2021-01-241-1/+1
| | | | | | | | | | | Replace the gendisk pointer in struct bio with a pointer to the newly improved struct block device. From that the gendisk can be trivially accessed with an extra indirection, but it also allows to directly look up all information related to partition remapping. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge tag 'dio_for_v5.10-rc1' of ↵Linus Torvalds2020-10-151-39/+30
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull direct-io fix from Jan Kara: "Fix for unaligned direct IO read past EOF in legacy DIO code" * tag 'dio_for_v5.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: direct-io: defer alignment check until after the EOF check direct-io: don't force writeback for reads beyond EOF direct-io: clean up error paths of do_blockdev_direct_IO
| * direct-io: defer alignment check until after the EOF checkGabriel Krisman Bertazi2020-10-081-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Prior to commit 9fe55eea7e4b ("Fix race when checking i_size on direct i/o read"), an unaligned direct read past end of file would trigger EOF, since generic_file_aio_read detected this read-at-EOF condition and skipped the direct IO read entirely, returning 0. After that change, the read now reaches dio_generic, which detects the misalignment and returns EINVAL. This consolidates the generic direct-io to follow the same behavior of filesystems. Apparently, this fix will only affect ocfs2 since other filesystems do this verification before calling do_blockdev_direct_IO, with the exception of f2fs, which has the same bug, but is fixed in the next patch. it can be verified by a read loop on a file that does a partial read before EOF (On file that doesn't end at an aligned address). The following code fails on an unaligned file on filesystems without prior validation without this patch, but not on btrfs, ext4, and xfs. while (done < total) { ssize_t delta = pread(fd, buf + done, total - done, off + done); if (!delta) break; ... } Fix this regression by moving the misalignment check to after the EOF check added by commit 74cedf9b6c60 ("direct-io: Fix negative return from dio read beyond eof"). Based on a patch by Jamie Liu. Link: https://lore.kernel.org/r/20201008062620.2928326-4-krisman@collabora.com Reported-by: Jamie Liu <jamieliu@google.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Jan Kara <jack@suse.cz>
| * direct-io: don't force writeback for reads beyond EOFGabriel Krisman Bertazi2020-10-081-13/+11
| | | | | | | | | | | | | | | | | | | | | | | | If a DIO read starts past EOF, the kernel won't attempt it, so we don't need to flush dirty pages before failing the syscall. Link: https://lore.kernel.org/r/20201008062620.2928326-3-krisman@collabora.com Suggested-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Jan Kara <jack@suse.cz>
| * direct-io: clean up error paths of do_blockdev_direct_IOGabriel Krisman Bertazi2020-10-081-21/+14
| | | | | | | | | | | | | | | | | | | | | | In preparation to resort DIO checks, reduce code duplication of error handling in do_blockdev_direct_IO. Link: https://lore.kernel.org/r/20201008062620.2928326-2-krisman@collabora.com Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: Jan Kara <jack@suse.cz>
* | fs: remove no longer used dio_end_io()Goldwyn Rodrigues2020-10-071-19/+0
|/ | | | | | | | | | | | | | Since we removed the last user of dio_end_io() when btrfs got converted to iomap infrastructure ("btrfs: switch to iomap for direct IO"), remove the helper function dio_end_io(). Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* block: remove the bd_queue field from struct block_deviceChristoph Hellwig2020-07-011-2/+2
| | | | | | | | Just use bd_disk->queue instead. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge tag 'for-5.8-part2-tag' of ↵Linus Torvalds2020-06-141-0/+19
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs updates from David Sterba: "This reverts the direct io port to iomap infrastructure of btrfs merged in the first pull request. We found problems in invalidate page that don't seem to be fixable as regressions or without changing iomap code that would not affect other filesystems. There are four reverts in total, but three of them are followup cleanups needed to revert a43a67a2d715 cleanly. The result is the buffer head based implementation of direct io. Reverts are not great, but under current circumstances I don't see better options" * tag 'for-5.8-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: Revert "btrfs: switch to iomap_dio_rw() for dio" Revert "fs: remove dio_end_io()" Revert "btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK" Revert "btrfs: split btrfs_direct_IO to read and write part"
| * Revert "fs: remove dio_end_io()"David Sterba2020-06-091-0/+19
| | | | | | | | | | | | | | | | | | This reverts commit b75b7ca7c27dfd61dba368f390b7d4dc20b3a8cb. The patch restores a helper that was not necessary after direct IO port to iomap infrastructure, which gets reverted. Signed-off-by: David Sterba <dsterba@suse.com>
* | Merge tag 'for-5.8-tag' of ↵Linus Torvalds2020-06-021-19/+0
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs updates from David Sterba: "Highlights: - speedup dead root detection during orphan cleanup, eg. when there are many deleted subvolumes waiting to be cleaned, the trees are now looked up in radix tree instead of a O(N^2) search - snapshot creation with inherited qgroup will mark the qgroup inconsistent, requires a rescan - send will emit file capabilities after chown, this produces a stream that does not need postprocessing to set the capabilities again - direct io ported to iomap infrastructure, cleaned up and simplified code, notably removing last use of struct buffer_head in btrfs code Core changes: - factor out backreference iteration, to be used by ordinary backreferences and relocation code - improved global block reserve utilization * better logic to serialize requests * increased maximum available for unlink * improved handling on large pages (64K) - direct io cleanups and fixes * simplify layering, where cloned bios were unnecessarily created for some cases * error handling fixes (submit, endio) * remove repair worker thread, used to avoid deadlocks during repair - refactored block group reading code, preparatory work for new type of block group storage that should improve mount time on large filesystems Cleanups: - cleaned up (and slightly sped up) set/get helpers for metadata data structure members - root bit REF_COWS got renamed to SHAREABLE to reflect the that the blocks of the tree get shared either among subvolumes or with the relocation trees Fixes: - when subvolume deletion fails due to ENOSPC, the filesystem is not turned read-only - device scan deals with devices from other filesystems that changed ownership due to overwrite (mkfs) - fix a race between scrub and block group removal/allocation - fix long standing bug of a runaway balance operation, printing the same line to the syslog, caused by a stale status bit on a reloc tree that prevented progress - fix corrupt log due to concurrent fsync of inodes with shared extents - fix space underflow for NODATACOW and buffered writes when it for some reason needs to fallback to COW mode" * tag 'for-5.8-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (133 commits) btrfs: fix space_info bytes_may_use underflow during space cache writeout btrfs: fix space_info bytes_may_use underflow after nocow buffered write btrfs: fix wrong file range cleanup after an error filling dealloc range btrfs: remove redundant local variable in read_block_for_search btrfs: open code key_search btrfs: split btrfs_direct_IO to read and write part btrfs: remove BTRFS_INODE_READDIO_NEED_LOCK fs: remove dio_end_io() btrfs: switch to iomap_dio_rw() for dio iomap: remove lockdep_assert_held() iomap: add a filesystem hook for direct I/O bio submission fs: export generic_file_buffered_read() btrfs: turn space cache writeout failure messages into debug messages btrfs: include error on messages about failure to write space/inode caches btrfs: remove useless 'fail_unlock' label from btrfs_csum_file_blocks() btrfs: do not ignore error from btrfs_next_leaf() when inserting checksums btrfs: make checksum item extension more efficient btrfs: fix corrupt log due to concurrent fsync of inodes with shared extents btrfs: unexport btrfs_compress_set_level() btrfs: simplify iget helpers ...
| * fs: remove dio_end_io()Goldwyn Rodrigues2020-05-281-19/+0
| | | | | | | | | | | | | | | | | | | | | | | | Since we removed the last user of dio_end_io(), remove the helper function dio_end_io(). Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
* | block: add blk_io_schedule() for avoiding task hung in sync dioMing Lei2020-05-121-1/+1
|/ | | | | | | | | | | | | | | | | | | | Sync dio could be big, or may take long time in discard or in case of IO failure. We have prevented task hung in submit_bio_wait() and blk_execute_rq(), so apply the same trick for prevent task hung from happening in sync dio. Add helper of blk_io_schedule() and use io_schedule_timeout() to prevent task hung warning. Signed-off-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Bart Van Assche <bvanassche@acm.org> Cc: Salman Qazi <sqazi@google.com> Cc: Jesse Barnes <jsbarnes@google.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Bart Van Assche <bvanassche@acm.org> Cc: Hannes Reinecke <hare@suse.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* fs/direct-io.c: include fs/internal.h for missing prototypeEric Biggers2020-01-041-0/+2
| | | | | | | | | | | | | Include fs/internal.h to address the following 'sparse' warning: fs/direct-io.c:591:5: warning: symbol 'sb_init_dio_done_wq' was not declared. Should it be static? Link: http://lkml.kernel.org/r/20191209234544.128302-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/direct-io.c: keep dio_warn_stale_pagecache() when CONFIG_BLOCK=nKonstantin Khlebnikov2019-12-011-21/+0
| | | | | | | | | | | | | | | | | | | | This helper prints warning if direct I/O write failed to invalidate cache, and set EIO at inode to warn usersapce about possible data corruption. See also commit 5a9d929d6e13 ("iomap: report collisions between directio and buffered writes to userspace"). Direct I/O is supported by non-disk filesystems, for example NFS. Thus generic code needs this even in kernel without CONFIG_BLOCK. Link: http://lkml.kernel.org/r/157270038074.4812.7980855544557488880.stgit@buzz Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Jens Axboe <axboe@kernel.dk> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs/direct-io.c: fix kernel-doc warningRandy Dunlap2019-10-141-2/+1
| | | | | | | | | | | | | | | | | Fix kernel-doc warning in fs/direct-io.c: fs/direct-io.c:258: warning: Excess function parameter 'offset' description in 'dio_complete' Also, don't mark this function as having kernel-doc notation since it is not exported. Link: http://lkml.kernel.org/r/97908511-4328-4a56-17fe-f43a1d7aa470@infradead.org Fixes: 6d544bb4d901 ("dio: centralize completion in dio_complete()") Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Zach Brown <zab@zabbo.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* direct-io: use bio_release_pages in dio_bio_completeChristoph Hellwig2019-06-291-12/+3
| | | | | | | | Use bio_release_pages instead of duplicating it. Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* treewide: Add SPDX license identifier for missed filesThomas Gleixner2019-05-211-0/+1
| | | | | | | | | | | | | | | | | Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* block: remove the i argument to bio_for_each_segment_allChristoph Hellwig2019-04-301-2/+1
| | | | | | | | | | | | | | We only have two callers that need the integer loop iterator, and they can easily maintain it themselves. Suggested-by: Matthew Wilcox <willy@infradead.org> Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Acked-by: David Sterba <dsterba@suse.com> Reviewed-by: Hannes Reinecke <hare@suse.com> Acked-by: Coly Li <colyli@suse.de> Reviewed-by: Matthew Wilcox <willy@infradead.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* block: allow bio_for_each_segment_all() to iterate over multi-page bvecMing Lei2019-02-151-1/+3
| | | | | | | | | | | | | | This patch introduces one extra iterator variable to bio_for_each_segment_all(), then we can allow bio_for_each_segment_all() to iterate over multi-page bvec. Given it is just one mechannical & simple change on all bio_for_each_segment_all() users, this patch does tree-wide change in one single patch, so that we can avoid to use a temporary helper for this conversion. Reviewed-by: Omar Sandoval <osandov@fb.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* direct-io: allow direct writes to empty inodesErnesto A. Fernández2019-01-221-2/+3
| | | | | | | | | | | | | | | | | On a DIO_SKIP_HOLES filesystem, the ->get_block() method is currently not allowed to create blocks for an empty inode. This confusion comes from trying to bit shift a negative number, so check the size of the inode first. The problem is most visible for hfsplus, because the fallback to buffered I/O doesn't happen and the write fails with EIO. This is in part the fault of the module, because it gives a wrong return value on ->get_block(); that will be fixed in a separate patch. Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge tag 'v4.20-rc5' into for-4.21/blockJens Axboe2018-12-041-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull in v4.20-rc5, solving a conflict we'll otherwise get in aio.c and also getting the merge fix that went into mainline that users are hitting testing for-4.21/block and/or for-next. * tag 'v4.20-rc5': (664 commits) Linux 4.20-rc5 PCI: Fix incorrect value returned from pcie_get_speed_cap() MAINTAINERS: Update linux-mips mailing list address ocfs2: fix potential use after free mm/khugepaged: fix the xas_create_range() error path mm/khugepaged: collapse_shmem() do not crash on Compound mm/khugepaged: collapse_shmem() without freezing new_page mm/khugepaged: minor reorderings in collapse_shmem() mm/khugepaged: collapse_shmem() remember to clear holes mm/khugepaged: fix crashes due to misaccounted holes mm/khugepaged: collapse_shmem() stop if punched or truncated mm/huge_memory: fix lockdep complaint on 32-bit i_size_read() mm/huge_memory: splitting set mapping+index before unfreeze mm/huge_memory: rename freeze_page() to unmap_page() initramfs: clean old path before creating a hardlink kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc() as notrace psi: make disabling/enabling easier for vendor kernels proc: fixup map_files test on arm debugobjects: avoid recursive calls with kmemleak userfaultfd: shmem: UFFDIO_COPY: set the page dirty if VM_WRITE is not set ...
| * fs: fix lost error code in dio_completeMaximilian Heyne2018-11-301-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit e259221763a40403d5bb232209998e8c45804ab8 ("fs: simplify the generic_write_sync prototype") reworked callers of generic_write_sync(), and ended up dropping the error return for the directio path. Prior to that commit, in dio_complete(), an error would be bubbled up the stack, but after that commit, errors passed on to dio_complete were eaten up. This was reported on the list earlier, and a fix was proposed in https://lore.kernel.org/lkml/20160921141539.GA17898@infradead.org/, but never followed up with. We recently hit this bug in our testing where fencing io errors, which were previously erroring out with EIO, were being returned as success operations after this commit. The fix proposed on the list earlier was a little short -- it would have still called generic_write_sync() in case `ret` already contained an error. This fix ensures generic_write_sync() is only called when there's no pending error in the write. Additionally, transferred is replaced with ret to bring this code in line with other callers. Fixes: e259221763a4 ("fs: simplify the generic_write_sync prototype") Reported-by: Ravi Nankani <rnankani@amazon.com> Signed-off-by: Maximilian Heyne <mheyne@amazon.de> Reviewed-by: Christoph Hellwig <hch@lst.de> CC: Torsten Mehlan <tomeh@amazon.de> CC: Uwe Dannowski <uwed@amazon.de> CC: Amit Shah <aams@amazon.de> CC: David Woodhouse <dwmw@amazon.co.uk> CC: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | block: make blk_poll() take a parameter on whether to spin or notJens Axboe2018-11-261-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | blk_poll() has always kept spinning until it found an IO. This is fine for SYNC polling, since we need to find one request we have pending, but in preparation for ASYNC polling it can be beneficial to just check if we have any entries available or not. Existing callers are converted to pass in 'spin == true', to retain the old behavior. Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | block: add REQ_HIPRI and inherit it from IOCB_HIPRIJens Axboe2018-11-071-0/+2
|/ | | | | | | | | | | | | We use IOCB_HIPRI to poll for IO in the caller instead of scheduling. This information is not available for (or after) IO submission. The driver may make different queue choices based on the type of IO, so make the fact that we will poll for this IO known to the lower layers as well. Reviewed-by: Hannes Reinecke <hare@suse.com> Reviewed-by: Keith Busch <keith.busch@intel.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* iov_iter: Use accessor functionDavid Howells2018-10-241-1/+1
| | | | | | | | | Use accessor functions to access an iterator's type and direction. This allows for the possibility of using some other method of determining the type of iterator than if-chains with bitwise-AND conditions. Signed-off-by: David Howells <dhowells@redhat.com>
* block: consistently use GFP_NOIO instead of __GFP_NORECLAIMChristoph Hellwig2018-05-141-2/+2
| | | | | | | | | Same numerical value (for now at least), but a much better documentation of intent. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Hannes Reinecke <hare@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* Merge branch 'akpm' (patches from Andrew)Linus Torvalds2018-04-061-5/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Merge updates from Andrew Morton: - a few misc things - ocfs2 updates - the v9fs maintainers have been missing for a long time. I've taken over v9fs patch slinging. - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (116 commits) mm,oom_reaper: check for MMF_OOM_SKIP before complaining mm/ksm: fix interaction with THP mm/memblock.c: cast constant ULLONG_MAX to phys_addr_t headers: untangle kmemleak.h from mm.h include/linux/mmdebug.h: make VM_WARN* non-rvals mm/page_isolation.c: make start_isolate_page_range() fail if already isolated mm: change return type to vm_fault_t mm, oom: remove 3% bonus for CAP_SYS_ADMIN processes mm, page_alloc: wakeup kcompactd even if kswapd cannot free more memory kernel/fork.c: detect early free of a live mm mm: make counting of list_lru_one::nr_items lockless mm/swap_state.c: make bool enable_vma_readahead and swap_vma_readahead() static block_invalidatepage(): only release page if the full page was invalidated mm: kernel-doc: add missing parameter descriptions mm/swap.c: remove @cold parameter description for release_pages() mm/nommu: remove description of alloc_vm_area zram: drop max_zpage_size and use zs_huge_class_size() zsmalloc: introduce zs_huge_class_size() mm: fix races between swapoff and flush dcache fs/direct-io.c: minor cleanups in do_blockdev_direct_IO ...
| * fs/direct-io.c: minor cleanups in do_blockdev_direct_IONikolay Borisov2018-04-051-5/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We already get the block counts and calculate the end block at the beginning of the function. Let's use the local variables for consistency and readability. No functional changes [akpm@linux-foundation.org: constify the locals to prevent future slipups] Link: http://lkml.kernel.org/r/1519638870-17756-1-git-send-email-nborisov@suse.com Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Jeff Moyer <jmoyer@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | direct-io: Remove unused DIO_SKIP_DIO_COUNT logicNikolay Borisov2018-03-121-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | This flag was added by fe0f07d08ee3 ("direct-io: only inc/deci inode->i_dio_count for file systems") as means to optimise the atomic modificaiton of the variable for blockdevices. However with the advent of 542ff7bf18c6 ("block: new direct I/O implementation") it became unused. So let's remove it. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* | direct-io: Remove unused DIO_ASYNC_EXTEND flagNikolay Borisov2018-03-121-2/+1
|/ | | | | | | | | | | This flag was added by 6039257378e4 ("direct-io: add flag to allow aio writes beyond i_size") to support XFS. However, with the rework of XFS' DIO's path to use iomap in acdda3aae146 ("xfs: use iomap_dio_rw") it became redundant. So let's remove it. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* direct-io: Fix sleep in atomic due to sync AIOJan Kara2018-02-261-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | Commit e864f39569f4 "fs: add RWF_DSYNC aand RWF_SYNC" added additional way for direct IO to become synchronous and thus trigger fsync from the IO completion handler. Then commit 9830f4be159b "fs: Use RWF_* flags for AIO operations" allowed these flags to be set for AIO as well. However that commit forgot to update the condition checking whether the IO completion handling should be defered to a workqueue and thus AIO DIO with RWF_[D]SYNC set will call fsync() from IRQ context resulting in sleep in atomic. Fix the problem by checking directly iocb flags (the same way as it is done in dio_complete()) instead of checking all conditions that could lead to IO being synchronous. CC: Christoph Hellwig <hch@lst.de> CC: Goldwyn Rodrigues <rgoldwyn@suse.com> CC: stable@vger.kernel.org Reported-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Fixes: 9830f4be159b29399d107bffb99e0132bc5aedd4 Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <axboe@kernel.dk>
* iomap: report collisions between directio and buffered writes to userspaceDarrick J. Wong2018-01-081-1/+23
| | | | | | | | | | | | | | | | | 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>
* Merge branch 'for-4.15/block' of git://git.kernel.dk/linux-blockLinus Torvalds2017-11-141-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ...
| * block: add a poll_fn callback to struct request_queueChristoph Hellwig2017-11-031-1/+1
| | | | | | | | | | | | | | | | | | 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>
* | locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns ↵Mark Rutland2017-10-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge tag 'xfs-4.14-fixes-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds2017-10-181-8/+12
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * | fs: invalidate page cache after end_io() in dio completionEryu Guan2017-10-161-8/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | | Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds2017-10-181-6/+13
|\ \ \ | |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * | fs: Avoid invalidation in interrupt context in dio_complete()Lukas Czerner2017-10-171-6/+13
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* / direct-io: Prevent NULL pointer access in submit_page_sectionAndreas Gruenbacher2017-10-101-1/+2
|/ | | | | | | | | | | | | | 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>
* fs: Fix page cache inconsistency when mixing buffered and AIO DIOLukas Czerner2017-09-251-6/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* block: replace bi_bdev with a gendisk pointer and partitions indexChristoph Hellwig2017-08-231-4/+4
| | | | | | | | | | | | | | | | | | | | 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>