1. 19 Nov, 2020 2 commits
    • Darrick J. Wong's avatar
      xfs: revert "xfs: fix rmap key and record comparison functions" · eb840907
      Darrick J. Wong authored
      This reverts commit 6ff646b2.
      
      Your maintainer committed a major braino in the rmap code by adding the
      attr fork, bmbt, and unwritten extent usage bits into rmap record key
      comparisons.  While XFS uses the usage bits *in the rmap records* for
      cross-referencing metadata in xfs_scrub and xfs_repair, it only needs
      the owner and offset information to distinguish between reverse mappings
      of the same physical extent into the data fork of a file at multiple
      offsets.  The other bits are not important for key comparisons for index
      lookups, and never have been.
      
      Eric Sandeen reports that this causes regressions in generic/299, so
      undo this patch before it does more damage.
      Reported-by: default avatarEric Sandeen <sandeen@sandeen.net>
      Fixes: 6ff646b2 ("xfs: fix rmap key and record comparison functions")
      Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Reviewed-by: default avatarEric Sandeen <sandeen@redhat.com>
      eb840907
    • Dave Chinner's avatar
      xfs: don't allow NOWAIT DIO across extent boundaries · 883a790a
      Dave Chinner authored
      Jens has reported a situation where partial direct IOs can be issued
      and completed yet still return -EAGAIN. We don't want this to report
      a short IO as we want XFS to complete user DIO entirely or not at
      all.
      
      This partial IO situation can occur on a write IO that is split
      across an allocated extent and a hole, and the second mapping is
      returning EAGAIN because allocation would be required.
      
      The trivial reproducer:
      
      $ sudo xfs_io -fdt -c "pwrite 0 4k" -c "pwrite -V 1 -b 8k -N 0 8k" /mnt/scr/foo
      wrote 4096/4096 bytes at offset 0
      4 KiB, 1 ops; 0.0001 sec (27.509 MiB/sec and 7042.2535 ops/sec)
      pwrite: Resource temporarily unavailable
      $
      
      The pwritev2(0, 8kB, RWF_NOWAIT) call returns EAGAIN having done
      the first 4kB write:
      
       xfs_file_direct_write: dev 259:1 ino 0x83 size 0x1000 offset 0x0 count 0x2000
       iomap_apply:          dev 259:1 ino 0x83 pos 0 length 8192 flags WRITE|DIRECT|NOWAIT (0x31) ops xfs_direct_write_iomap_ops caller iomap_dio_rw actor iomap_dio_actor
       xfs_ilock_nowait:     dev 259:1 ino 0x83 flags ILOCK_SHARED caller xfs_ilock_for_iomap
       xfs_iunlock:          dev 259:1 ino 0x83 flags ILOCK_SHARED caller xfs_direct_write_iomap_begin
       xfs_iomap_found:      dev 259:1 ino 0x83 size 0x1000 offset 0x0 count 8192 fork data startoff 0x0 startblock 24 blockcount 0x1
       iomap_apply_dstmap:   dev 259:1 ino 0x83 bdev 259:1 addr 102400 offset 0 length 4096 type MAPPED flags DIRTY
      
      Here the first iomap loop has mapped the first 4kB of the file and
      issued the IO, and we enter the second iomap_apply loop:
      
       iomap_apply: dev 259:1 ino 0x83 pos 4096 length 4096 flags WRITE|DIRECT|NOWAIT (0x31) ops xfs_direct_write_iomap_ops caller iomap_dio_rw actor iomap_dio_actor
       xfs_ilock_nowait:     dev 259:1 ino 0x83 flags ILOCK_SHARED caller xfs_ilock_for_iomap
       xfs_iunlock:          dev 259:1 ino 0x83 flags ILOCK_SHARED caller xfs_direct_write_iomap_begin
      
      And we exit with -EAGAIN out because we hit the allocate case trying
      to make the second 4kB block.
      
      Then IO completes on the first 4kB and the original IO context
      completes and unlocks the inode, returning -EAGAIN to userspace:
      
       xfs_end_io_direct_write: dev 259:1 ino 0x83 isize 0x1000 disize 0x1000 offset 0x0 count 4096
       xfs_iunlock:          dev 259:1 ino 0x83 flags IOLOCK_SHARED caller xfs_file_dio_aio_write
      
      There are other vectors to the same problem when we re-enter the
      mapping code if we have to make multiple mappinfs under NOWAIT
      conditions. e.g. failing trylocks, COW extents being found,
      allocation being required, and so on.
      
      Avoid all these potential problems by only allowing IOMAP_NOWAIT IO
      to go ahead if the mapping we retrieve for the IO spans an entire
      allocated extent. This avoids the possibility of subsequent mappings
      to complete the IO from triggering NOWAIT semantics by any means as
      NOWAIT IO will now only enter the mapping code once per NOWAIT IO.
      Reported-and-tested-by: default avatarJens Axboe <axboe@kernel.dk>
      Signed-off-by: default avatarDave Chinner <dchinner@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      883a790a
  2. 18 Nov, 2020 6 commits
  3. 11 Nov, 2020 5 commits
  4. 05 Nov, 2020 1 commit
  5. 04 Nov, 2020 5 commits
    • Darrick J. Wong's avatar
      xfs: fix scrub flagging rtinherit even if there is no rt device · c1f6b1ac
      Darrick J. Wong authored
      The kernel has always allowed directories to have the rtinherit flag
      set, even if there is no rt device, so this check is wrong.
      
      Fixes: 80e4e126 ("xfs: scrub inodes")
      Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      c1f6b1ac
    • Darrick J. Wong's avatar
      xfs: fix missing CoW blocks writeback conversion retry · c2f09217
      Darrick J. Wong authored
      In commit 7588cbee, we tried to fix a race stemming from the lack of
      coordination between higher level code that wants to allocate and remap
      CoW fork extents into the data fork.  Christoph cites as examples the
      always_cow mode, and a directio write completion racing with writeback.
      
      According to the comments before the goto retry, we want to restart the
      lookup to catch the extent in the data fork, but we don't actually reset
      whichfork or cow_fsb, which means the second try executes using stale
      information.  Up until now I think we've gotten lucky that either
      there's something left in the CoW fork to cause cow_fsb to be reset, or
      either data/cow fork sequence numbers have advanced enough to force a
      fresh lookup from the data fork.  However, if we reach the retry with an
      empty stable CoW fork and a stable data fork, neither of those things
      happens.  The retry foolishly re-calls xfs_convert_blocks on the CoW
      fork which fails again.  This time, we toss the write.
      
      I've recently been working on extending reflink to the realtime device.
      When the realtime extent size is larger than a single block, we have to
      force the page cache to CoW the entire rt extent if a write (or
      fallocate) are not aligned with the rt extent size.  The strategy I've
      chosen to deal with this is derived from Dave's blocksize > pagesize
      series: dirtying around the write range, and ensuring that writeback
      always starts mapping on an rt extent boundary.  This has brought this
      race front and center, since generic/522 blows up immediately.
      
      However, I'm pretty sure this is a bug outright, independent of that.
      
      Fixes: 7588cbee ("xfs: retry COW fork delalloc conversion when no extent was found")
      Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      c2f09217
    • Brian Foster's avatar
      iomap: clean up writeback state logic on writepage error · 50e7d6c7
      Brian Foster authored
      The iomap writepage error handling logic is a mash of old and
      slightly broken XFS writepage logic. When keepwrite writeback state
      tracking was introduced in XFS in commit 0d085a52 ("xfs: ensure
      WB_SYNC_ALL writeback handles partial pages correctly"), XFS had an
      additional cluster writeback context that scanned ahead of
      ->writepage() to process dirty pages over the current ->writepage()
      extent mapping. This context expected a dirty page and required
      retention of the TOWRITE tag on partial page processing so the
      higher level writeback context would revisit the page (in contrast
      to ->writepage(), which passes a page with the dirty bit already
      cleared).
      
      The cluster writeback mechanism was eventually removed and some of
      the error handling logic folded into the primary writeback path in
      commit 150d5be0 ("xfs: remove xfs_cancel_ioend"). This patch
      accidentally conflated the two contexts by using the keepwrite logic
      in ->writepage() without accounting for the fact that the page is
      not dirty. Further, the keepwrite logic has no practical effect on
      the core ->writepage() caller (write_cache_pages()) because it never
      revisits a page in the current function invocation.
      
      Technically, the page should be redirtied for the keepwrite logic to
      have any effect. Otherwise, write_cache_pages() may find the tagged
      page but will skip it since it is clean. Even if the page was
      redirtied, however, there is still no practical effect to keepwrite
      since write_cache_pages() does not wrap around within a single
      invocation of the function. Therefore, the dirty page would simply
      end up retagged on the next writeback sequence over the associated
      range.
      
      All that being said, none of this really matters because redirtying
      a partially processed page introduces a potential infinite redirty
      -> writeback failure loop that deviates from the current design
      principle of clearing the dirty state on writepage failure to avoid
      building up too much dirty, unreclaimable memory on the system.
      Therefore, drop the spurious keepwrite usage and dirty state
      clearing logic from iomap_writepage_map(), treat the partially
      processed page the same as a fully processed page, and let the
      imminent ioend failure clean up the writeback state.
      Signed-off-by: default avatarBrian Foster <bfoster@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      50e7d6c7
    • Brian Foster's avatar
      iomap: support partial page discard on writeback block mapping failure · 763e4cdc
      Brian Foster authored
      iomap writeback mapping failure only calls into ->discard_page() if
      the current page has not been added to the ioend. Accordingly, the
      XFS callback assumes a full page discard and invalidation. This is
      problematic for sub-page block size filesystems where some portion
      of a page might have been mapped successfully before a failure to
      map a delalloc block occurs. ->discard_page() is not called in that
      error scenario and the bio is explicitly failed by iomap via the
      error return from ->prepare_ioend(). As a result, the filesystem
      leaks delalloc blocks and corrupts the filesystem block counters.
      
      Since XFS is the only user of ->discard_page(), tweak the semantics
      to invoke the callback unconditionally on mapping errors and provide
      the file offset that failed to map. Update xfs_discard_page() to
      discard the corresponding portion of the file and pass the range
      along to iomap_invalidatepage(). The latter already properly handles
      both full and sub-page scenarios by not changing any iomap or page
      state on sub-page invalidations.
      Signed-off-by: default avatarBrian Foster <bfoster@redhat.com>
      Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
      Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      763e4cdc
    • Brian Foster's avatar
      xfs: flush new eof page on truncate to avoid post-eof corruption · 869ae85d
      Brian Foster authored
      It is possible to expose non-zeroed post-EOF data in XFS if the new
      EOF page is dirty, backed by an unwritten block and the truncate
      happens to race with writeback. iomap_truncate_page() will not zero
      the post-EOF portion of the page if the underlying block is
      unwritten. The subsequent call to truncate_setsize() will, but
      doesn't dirty the page. Therefore, if writeback happens to complete
      after iomap_truncate_page() (so it still sees the unwritten block)
      but before truncate_setsize(), the cached page becomes inconsistent
      with the on-disk block. A mapped read after the associated page is
      reclaimed or invalidated exposes non-zero post-EOF data.
      
      For example, consider the following sequence when run on a kernel
      modified to explicitly flush the new EOF page within the race
      window:
      
      $ xfs_io -fc "falloc 0 4k" -c fsync /mnt/file
      $ xfs_io -c "pwrite 0 4k" -c "truncate 1k" /mnt/file
        ...
      $ xfs_io -c "mmap 0 4k" -c "mread -v 1k 8" /mnt/file
      00000400:  00 00 00 00 00 00 00 00  ........
      $ umount /mnt/; mount <dev> /mnt/
      $ xfs_io -c "mmap 0 4k" -c "mread -v 1k 8" /mnt/file
      00000400:  cd cd cd cd cd cd cd cd  ........
      
      Update xfs_setattr_size() to explicitly flush the new EOF page prior
      to the page truncate to ensure iomap has the latest state of the
      underlying block.
      
      Fixes: 68a9f5e7 ("xfs: implement iomap based buffered write path")
      Signed-off-by: default avatarBrian Foster <bfoster@redhat.com>
      Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
      869ae85d
  6. 29 Oct, 2020 1 commit
  7. 25 Oct, 2020 17 commits
  8. 24 Oct, 2020 3 commits
    • Linus Torvalds's avatar
      Merge tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block · d7691390
      Linus Torvalds authored
      Pull block fixes from Jens Axboe:
      
       - NVMe pull request from Christoph
           - rdma error handling fixes (Chao Leng)
           - fc error handling and reconnect fixes (James Smart)
           - fix the qid displace when tracing ioctl command (Keith Busch)
           - don't use BLK_MQ_REQ_NOWAIT for passthru (Chaitanya Kulkarni)
           - fix MTDT for passthru (Logan Gunthorpe)
           - blacklist Write Same on more devices (Kai-Heng Feng)
           - fix an uninitialized work struct (zhenwei pi)"
      
       - lightnvm out-of-bounds fix (Colin)
      
       - SG allocation leak fix (Doug)
      
       - rnbd fixes (Gioh, Guoqing, Jack)
      
       - zone error translation fixes (Keith)
      
       - kerneldoc markup fix (Mauro)
      
       - zram lockdep fix (Peter)
      
       - Kill unused io_context members (Yufen)
      
       - NUMA memory allocation cleanup (Xianting)
      
       - NBD config wakeup fix (Xiubo)
      
      * tag 'block-5.10-2020-10-24' of git://git.kernel.dk/linux-block: (27 commits)
        block: blk-mq: fix a kernel-doc markup
        nvme-fc: shorten reconnect delay if possible for FC
        nvme-fc: wait for queues to freeze before calling update_hr_hw_queues
        nvme-fc: fix error loop in create_hw_io_queues
        nvme-fc: fix io timeout to abort I/O
        null_blk: use zone status for max active/open
        nvmet: don't use BLK_MQ_REQ_NOWAIT for passthru
        nvmet: cleanup nvmet_passthru_map_sg()
        nvmet: limit passthru MTDS by BIO_MAX_PAGES
        nvmet: fix uninitialized work for zero kato
        nvme-pci: disable Write Zeroes on Sandisk Skyhawk
        nvme: use queuedata for nvme_req_qid
        nvme-rdma: fix crash due to incorrect cqe
        nvme-rdma: fix crash when connect rejected
        block: remove unused members for io_context
        blk-mq: remove the calling of local_memory_node()
        zram: Fix __zram_bvec_{read,write}() locking order
        skd_main: remove unused including <linux/version.h>
        sgl_alloc_order: fix memory leak
        lightnvm: fix out-of-bounds write to array devices->info[]
        ...
      d7691390
    • Linus Torvalds's avatar
      Merge tag 'io_uring-5.10-2020-10-24' of git://git.kernel.dk/linux-block · af004187
      Linus Torvalds authored
      Pull io_uring fixes from Jens Axboe:
      
       - fsize was missed in previous unification of work flags
      
       - Few fixes cleaning up the flags unification creds cases (Pavel)
      
       - Fix NUMA affinities for completely unplugged/replugged node for io-wq
      
       - Two fallout fixes from the set_fs changes. One local to io_uring, one
         for the splice entry point that io_uring uses.
      
       - Linked timeout fixes (Pavel)
      
       - Removal of ->flush() ->files work-around that we don't need anymore
         with referenced files (Pavel)
      
       - Various cleanups (Pavel)
      
      * tag 'io_uring-5.10-2020-10-24' of git://git.kernel.dk/linux-block:
        splice: change exported internal do_splice() helper to take kernel offset
        io_uring: make loop_rw_iter() use original user supplied pointers
        io_uring: remove req cancel in ->flush()
        io-wq: re-set NUMA node affinities if CPUs come online
        io_uring: don't reuse linked_timeout
        io_uring: unify fsize with def->work_flags
        io_uring: fix racy REQ_F_LINK_TIMEOUT clearing
        io_uring: do poll's hash_node init in common code
        io_uring: inline io_poll_task_handler()
        io_uring: remove extra ->file check in poll prep
        io_uring: make cached_cq_overflow non atomic_t
        io_uring: inline io_fail_links()
        io_uring: kill ref get/drop in personality init
        io_uring: flags-based creds init in queue
      af004187
    • Linus Torvalds's avatar
      Merge tag 'libata-5.10-2020-10-24' of git://git.kernel.dk/linux-block · cb6b2897
      Linus Torvalds authored
      Pull libata fixes from Jens Axboe:
       "Two minor libata fixes:
      
         - Fix a DMA boundary mask regression for sata_rcar (Geert)
      
         - kerneldoc markup fix (Mauro)"
      
      * tag 'libata-5.10-2020-10-24' of git://git.kernel.dk/linux-block:
        ata: fix some kernel-doc markups
        ata: sata_rcar: Fix DMA boundary mask
      cb6b2897