Commit Graph

358 Commits

Author SHA1 Message Date
Linus Torvalds e253d98f5b Merge branch 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull nowait read support from Al Viro:
 "Support IOCB_NOWAIT for buffered reads and block devices"

* 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  block_dev: support RFW_NOWAIT on block device nodes
  fs: support RWF_NOWAIT for buffered reads
  fs: support IOCB_NOWAIT in generic_file_buffered_read
  fs: pass iocb to do_generic_file_read
2017-09-14 19:29:55 -07:00
Linus Torvalds d34fc1adf0 Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:

 - various misc bits

 - DAX updates

 - OCFS2

 - most of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (119 commits)
  mm,fork: introduce MADV_WIPEONFORK
  x86,mpx: make mpx depend on x86-64 to free up VMA flag
  mm: add /proc/pid/smaps_rollup
  mm: hugetlb: clear target sub-page last when clearing huge page
  mm: oom: let oom_reap_task and exit_mmap run concurrently
  swap: choose swap device according to numa node
  mm: replace TIF_MEMDIE checks by tsk_is_oom_victim
  mm, oom: do not rely on TIF_MEMDIE for memory reserves access
  z3fold: use per-cpu unbuddied lists
  mm, swap: don't use VMA based swap readahead if HDD is used as swap
  mm, swap: add sysfs interface for VMA based swap readahead
  mm, swap: VMA based swap readahead
  mm, swap: fix swap readahead marking
  mm, swap: add swap readahead hit statistics
  mm/vmalloc.c: don't reinvent the wheel but use existing llist API
  mm/vmstat.c: fix wrong comment
  selftests/memfd: add memfd_create hugetlbfs selftest
  mm/shmem: add hugetlbfs support to memfd_create()
  mm, devm_memremap_pages: use multi-order radix for ZONE_DEVICE lookups
  mm/vmalloc.c: halve the number of comparisons performed in pcpu_get_vm_areas()
  ...
2017-09-06 20:49:49 -07:00
Ross Zwisler 91d25ba8a6 dax: use common 4k zero page for dax mmap reads
When servicing mmap() reads from file holes the current DAX code
allocates a page cache page of all zeroes and places the struct page
pointer in the mapping->page_tree radix tree.

This has three major drawbacks:

1) It consumes memory unnecessarily. For every 4k page that is read via
   a DAX mmap() over a hole, we allocate a new page cache page. This
   means that if you read 1GiB worth of pages, you end up using 1GiB of
   zeroed memory. This is easily visible by looking at the overall
   memory consumption of the system or by looking at /proc/[pid]/smaps:

	7f62e72b3000-7f63272b3000 rw-s 00000000 103:00 12   /root/dax/data
	Size:            1048576 kB
	Rss:             1048576 kB
	Pss:             1048576 kB
	Shared_Clean:          0 kB
	Shared_Dirty:          0 kB
	Private_Clean:   1048576 kB
	Private_Dirty:         0 kB
	Referenced:      1048576 kB
	Anonymous:             0 kB
	LazyFree:              0 kB
	AnonHugePages:         0 kB
	ShmemPmdMapped:        0 kB
	Shared_Hugetlb:        0 kB
	Private_Hugetlb:       0 kB
	Swap:                  0 kB
	SwapPss:               0 kB
	KernelPageSize:        4 kB
	MMUPageSize:           4 kB
	Locked:                0 kB

2) It is slower than using a common zero page because each page fault
   has more work to do. Instead of just inserting a common zero page we
   have to allocate a page cache page, zero it, and then insert it. Here
   are the average latencies of dax_load_hole() as measured by ftrace on
   a random test box:

    Old method, using zeroed page cache pages:	3.4 us
    New method, using the common 4k zero page:	0.8 us

   This was the average latency over 1 GiB of sequential reads done by
   this simple fio script:

     [global]
     size=1G
     filename=/root/dax/data
     fallocate=none
     [io]
     rw=read
     ioengine=mmap

3) The fact that we had to check for both DAX exceptional entries and
   for page cache pages in the radix tree made the DAX code more
   complex.

Solve these issues by following the lead of the DAX PMD code and using a
common 4k zero page instead.  As with the PMD code we will now insert a
DAX exceptional entry into the radix tree instead of a struct page
pointer which allows us to remove all the special casing in the DAX
code.

Note that we do still pretty aggressively check for regular pages in the
DAX radix tree, especially where we take action based on the bits set in
the page.  If we ever find a regular page in our radix tree now that
most likely means that someone besides DAX is inserting pages (which has
happened lots of times in the past), and we want to find that out early
and fail loudly.

This solution also removes the extra memory consumption.  Here is that
same /proc/[pid]/smaps after 1GiB of reading from a hole with the new
code:

	7f2054a74000-7f2094a74000 rw-s 00000000 103:00 12   /root/dax/data
	Size:            1048576 kB
	Rss:                   0 kB
	Pss:                   0 kB
	Shared_Clean:          0 kB
	Shared_Dirty:          0 kB
	Private_Clean:         0 kB
	Private_Dirty:         0 kB
	Referenced:            0 kB
	Anonymous:             0 kB
	LazyFree:              0 kB
	AnonHugePages:         0 kB
	ShmemPmdMapped:        0 kB
	Shared_Hugetlb:        0 kB
	Private_Hugetlb:       0 kB
	Swap:                  0 kB
	SwapPss:               0 kB
	KernelPageSize:        4 kB
	MMUPageSize:           4 kB
	Locked:                0 kB

Overall system memory consumption is similarly improved.

Another major change is that we remove dax_pfn_mkwrite() from our fault
flow, and instead rely on the page fault itself to make the PTE dirty
and writeable.  The following description from the patch adding the
vm_insert_mixed_mkwrite() call explains this a little more:

   "To be able to use the common 4k zero page in DAX we need to have our
    PTE fault path look more like our PMD fault path where a PTE entry
    can be marked as dirty and writeable as it is first inserted rather
    than waiting for a follow-up dax_pfn_mkwrite() =>
    finish_mkwrite_fault() call.

    Right now we can rely on having a dax_pfn_mkwrite() call because we
    can distinguish between these two cases in do_wp_page():

            case 1: 4k zero page => writable DAX storage
            case 2: read-only DAX storage => writeable DAX storage

    This distinction is made by via vm_normal_page(). vm_normal_page()
    returns false for the common 4k zero page, though, just as it does
    for DAX ptes. Instead of special casing the DAX + 4k zero page case
    we will simplify our DAX PTE page fault sequence so that it matches
    our DAX PMD sequence, and get rid of the dax_pfn_mkwrite() helper.
    We will instead use dax_iomap_fault() to handle write-protection
    faults.

    This means that insert_pfn() needs to follow the lead of
    insert_pfn_pmd() and allow us to pass in a 'mkwrite' flag. If
    'mkwrite' is set insert_pfn() will do the work that was previously
    done by wp_page_reuse() as part of the dax_pfn_mkwrite() call path"

Link: http://lkml.kernel.org/r/20170724170616.25810-4-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: "Darrick J. Wong" <darrick.wong@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-06 17:27:24 -07:00
Christoph Hellwig 91f9943e1c fs: support RWF_NOWAIT for buffered reads
This is based on the old idea and code from Milosz Tanski.  With the aio
nowait code it becomes mostly trivial now.  Buffered writes continue to
return -EOPNOTSUPP if RWF_NOWAIT is passed.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-09-04 19:04:23 -04:00
Christoph Hellwig d522d569d6 xfs: consolidate the various page fault handlers
Add a new __xfs_filemap_fault helper that implements all four page fault
callouts, and make these methods themselves small stubs that set the
correct write_fault flag, and exit early for the non-DAX case for the
hugepage related ones.

Also remove the extra size checking in the pfn_fault path, which is now
handled in the core DAX code.

Life would be so much simpler if we only had one method for all this.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 10:55:30 -07:00
Christoph Hellwig e7647fb491 iomap: return VM_FAULT_* codes from iomap_page_mkwrite
All callers will need the VM_FAULT_* flags, so convert in the helper.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-09-01 10:55:30 -07:00
Linus Torvalds 642338ba33 Changes for 4.13:
- Avoid quotacheck deadlocks
 - Fix transaction overflows when bunmapping fragmented files
 - Refactor directory readahead
 - Allow admin to configure if ASSERT is fatal
 - Improve transaction usage detail logging during overflows
 - Minor cleanups
 - Don't leak log items when the log shuts down
 - Remove double-underscore typedefs
 - Various preparation for online scrubbing
 - Introduce new error injection configuration sysfs knobs
 - Refactor dq_get_next to use extent map directly
 - Fix problems with iterating the page cache for unwritten data
 - Implement SEEK_{HOLE,DATA} via iomap
 - Refactor XFS to use iomap SEEK_HOLE and SEEK_DATA
 - Don't use MAXPATHLEN to check on-disk symlink target lengths
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Merge tag 'xfs-4.13-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull XFS updates from Darrick Wong:
 "Here are some changes for you for 4.13. For the most part it's fixes
  for bugs and deadlock problems, and preparation for online fsck in
  some future merge window.

   - Avoid quotacheck deadlocks

   - Fix transaction overflows when bunmapping fragmented files

   - Refactor directory readahead

   - Allow admin to configure if ASSERT is fatal

   - Improve transaction usage detail logging during overflows

   - Minor cleanups

   - Don't leak log items when the log shuts down

   - Remove double-underscore typedefs

   - Various preparation for online scrubbing

   - Introduce new error injection configuration sysfs knobs

   - Refactor dq_get_next to use extent map directly

   - Fix problems with iterating the page cache for unwritten data

   - Implement SEEK_{HOLE,DATA} via iomap

   - Refactor XFS to use iomap SEEK_HOLE and SEEK_DATA

   - Don't use MAXPATHLEN to check on-disk symlink target lengths"

* tag 'xfs-4.13-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (48 commits)
  xfs: don't crash on unexpected holes in dir/attr btrees
  xfs: rename MAXPATHLEN to XFS_SYMLINK_MAXLEN
  xfs: fix contiguous dquot chunk iteration livelock
  xfs: Switch to iomap for SEEK_HOLE / SEEK_DATA
  vfs: Add iomap_seek_hole and iomap_seek_data helpers
  vfs: Add page_cache_seek_hole_data helper
  xfs: remove a whitespace-only line from xfs_fs_get_nextdqblk
  xfs: rewrite xfs_dq_get_next_id using xfs_iext_lookup_extent
  xfs: Check for m_errortag initialization in xfs_errortag_test
  xfs: grab dquots without taking the ilock
  xfs: fix semicolon.cocci warnings
  xfs: Don't clear SGID when inheriting ACLs
  xfs: free cowblocks and retry on buffered write ENOSPC
  xfs: replace log_badcrc_factor knob with error injection tag
  xfs: convert drop_writes to use the errortag mechanism
  xfs: remove unneeded parameter from XFS_TEST_ERROR
  xfs: expose errortag knobs via sysfs
  xfs: make errortag a per-mountpoint structure
  xfs: free uncommitted transactions during log recovery
  xfs: don't allow bmap on rt files
  ...
2017-07-10 10:51:53 -07:00
Linus Torvalds 088737f44b Writeback error handling fixes (pile #2)
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Merge tag 'for-linus-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull Writeback error handling updates from Jeff Layton:
 "This pile represents the bulk of the writeback error handling fixes
  that I have for this cycle. Some of the earlier patches in this pile
  may look trivial but they are prerequisites for later patches in the
  series.

  The aim of this set is to improve how we track and report writeback
  errors to userland. Most applications that care about data integrity
  will periodically call fsync/fdatasync/msync to ensure that their
  writes have made it to the backing store.

  For a very long time, we have tracked writeback errors using two flags
  in the address_space: AS_EIO and AS_ENOSPC. Those flags are set when a
  writeback error occurs (via mapping_set_error) and are cleared as a
  side-effect of filemap_check_errors (as you noted yesterday). This
  model really sucks for userland.

  Only the first task to call fsync (or msync or fdatasync) will see the
  error. Any subsequent task calling fsync on a file will get back 0
  (unless another writeback error occurs in the interim). If I have
  several tasks writing to a file and calling fsync to ensure that their
  writes got stored, then I need to have them coordinate with one
  another. That's difficult enough, but in a world of containerized
  setups that coordination may even not be possible.

  But wait...it gets worse!

  The calls to filemap_check_errors can be buried pretty far down in the
  call stack, and there are internal callers of filemap_write_and_wait
  and the like that also end up clearing those errors. Many of those
  callers ignore the error return from that function or return it to
  userland at nonsensical times (e.g. truncate() or stat()). If I get
  back -EIO on a truncate, there is no reason to think that it was
  because some previous writeback failed, and a subsequent fsync() will
  (incorrectly) return 0.

  This pile aims to do three things:

   1) ensure that when a writeback error occurs that that error will be
      reported to userland on a subsequent fsync/fdatasync/msync call,
      regardless of what internal callers are doing

   2) report writeback errors on all file descriptions that were open at
      the time that the error occurred. This is a user-visible change,
      but I think most applications are written to assume this behavior
      anyway. Those that aren't are unlikely to be hurt by it.

   3) document what filesystems should do when there is a writeback
      error. Today, there is very little consistency between them, and a
      lot of cargo-cult copying. We need to make it very clear what
      filesystems should do in this situation.

  To achieve this, the set adds a new data type (errseq_t) and then
  builds new writeback error tracking infrastructure around that. Once
  all of that is in place, we change the filesystems to use the new
  infrastructure for reporting wb errors to userland.

  Note that this is just the initial foray into cleaning up this mess.
  There is a lot of work remaining here:

   1) convert the rest of the filesystems in a similar fashion. Once the
      initial set is in, then I think most other fs' will be fairly
      simple to convert. Hopefully most of those can in via individual
      filesystem trees.

   2) convert internal waiters on writeback to use errseq_t for
      detecting errors instead of relying on the AS_* flags. I have some
      draft patches for this for ext4, but they are not quite ready for
      prime time yet.

  This was a discussion topic this year at LSF/MM too. If you're
  interested in the gory details, LWN has some good articles about this:

      https://lwn.net/Articles/718734/
      https://lwn.net/Articles/724307/"

* tag 'for-linus-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  btrfs: minimal conversion to errseq_t writeback error reporting on fsync
  xfs: minimal conversion to errseq_t writeback error reporting
  ext4: use errseq_t based error handling for reporting data writeback errors
  fs: convert __generic_file_fsync to use errseq_t based reporting
  block: convert to errseq_t based writeback error tracking
  dax: set errors in mapping when writeback fails
  Documentation: flesh out the section in vfs.txt on storing and reporting writeback errors
  mm: set both AS_EIO/AS_ENOSPC and errseq_t in mapping_set_error
  fs: new infrastructure for writeback error handling and reporting
  lib: add errseq_t type and infrastructure for handling it
  mm: don't TestClearPageError in __filemap_fdatawait_range
  mm: clear AS_EIO/AS_ENOSPC when writeback initiation fails
  jbd2: don't clear and reset errors after waiting on writeback
  buffer: set errors in mapping at the time that the error occurs
  fs: check for writeback errors after syncing out buffers in generic_file_fsync
  buffer: use mapping_set_error instead of setting the flag
  mm: fix mapping_set_error call in me_pagecache_dirty
2017-07-07 19:38:17 -07:00
Jeff Layton 1b180274f5 xfs: minimal conversion to errseq_t writeback error reporting
Just check and advance the data errseq_t in struct file before
before returning from fsync on normal files. Internal filemap_*
callers are left as-is.

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-06 07:02:30 -04:00
Christoph Hellwig 9b2970aacf xfs: Switch to iomap for SEEK_HOLE / SEEK_DATA
Switch to the iomap_seek_hole and iomap_seek_data helpers for
implementing lseek SEEK_HOLE / SEEK_DATA, and remove all the
code that isn't needed any more.

Based on patches from Andreas Gruenbacher <agruenba@redhat.com>.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-07-02 22:46:13 -07:00
Brian Foster cf2cb7845d xfs: free cowblocks and retry on buffered write ENOSPC
XFS runs an eofblocks reclaim scan before returning an ENOSPC error to
userspace for buffered writes. This facilitates aggressive speculative
preallocation without causing user visible side effects such as
premature ENOSPC.

Run a cowblocks scan in the same situation to reclaim lingering COW fork
preallocation throughout the filesystem.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-06-27 18:23:21 -07:00
Darrick J. Wong acb9553cab xfs: pass along transaction context when reading directory block buffers
Teach the directory reading functions to pass along a transaction context
if one was supplied.  The directory scrub code will use transactions to
lock buffers and avoid deadlocking with itself in the case of loops.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-20 10:45:22 -07:00
Goldwyn Rodrigues 29a5d29ec1 xfs: nowait aio support
If IOCB_NOWAIT is set, bail if the i_rwsem is not lockable
immediately.

IF IOMAP_NOWAIT is set, return EAGAIN in xfs_file_iomap_begin
if it needs allocation either due to file extension, writing to a hole,
or COW or waiting for other DIOs to finish.

Return -EAGAIN if we don't have extent list in memory.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20 07:12:03 -06:00
Jan Kara a54fba8f5a xfs: Move handling of missing page into one place in xfs_find_get_desired_pgoff()
Currently several places in xfs_find_get_desired_pgoff() handle the case
of a missing page. Make them all handled in one place after the loop has
terminated.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-05-25 09:42:25 -07:00
Jan Kara d7fd24257a xfs: Fix off-by-in in loop termination in xfs_find_get_desired_pgoff()
There is an off-by-one error in loop termination conditions in
xfs_find_get_desired_pgoff() since 'end' may index a page beyond end of
desired range if 'endoff' is page aligned. It doesn't have any visible
effects but still it is good to fix it.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-05-25 09:42:25 -07:00
Jan Kara 5375023ae1 xfs: Fix missed holes in SEEK_HOLE implementation
XFS SEEK_HOLE implementation could miss a hole in an unwritten extent as
can be seen by the following command:

xfs_io -c "falloc 0 256k" -c "pwrite 0 56k" -c "pwrite 128k 8k"
       -c "seek -h 0" file
wrote 57344/57344 bytes at offset 0
56 KiB, 14 ops; 0.0000 sec (49.312 MiB/sec and 12623.9856 ops/sec)
wrote 8192/8192 bytes at offset 131072
8 KiB, 2 ops; 0.0000 sec (70.383 MiB/sec and 18018.0180 ops/sec)
Whence	Result
HOLE	139264

Where we can see that hole at offset 56k was just ignored by SEEK_HOLE
implementation. The bug is in xfs_find_get_desired_pgoff() which does
not properly detect the case when pages are not contiguous.

Fix the problem by properly detecting when found page has larger offset
than expected.

CC: stable@vger.kernel.org
Fixes: d126d43f63
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-05-25 09:42:25 -07:00
Eryu Guan 8affebe16d xfs: fix off-by-one on max nr_pages in xfs_find_get_desired_pgoff()
xfs_find_get_desired_pgoff() is used to search for offset of hole or
data in page range [index, end] (both inclusive), and the max number
of pages to search should be at least one, if end == index.
Otherwise the only page is missed and no hole or data is found,
which is not correct.

When block size is smaller than page size, this can be demonstrated
by preallocating a file with size smaller than page size and writing
data to the last block. E.g. run this xfs_io command on a 1k block
size XFS on x86_64 host.

  # xfs_io -fc "falloc 0 3k" -c "pwrite 2k 1k" \
  	    -c "seek -d 0" /mnt/xfs/testfile
  wrote 1024/1024 bytes at offset 2048
  1 KiB, 1 ops; 0.0000 sec (33.675 MiB/sec and 34482.7586 ops/sec)
  Whence  Result
  DATA    EOF

Data at offset 2k was missed, and lseek(2) returned ENXIO.

This is uncovered by generic/285 subtest 07 and 08 on ppc64 host,
where pagesize is 64k. Because a recent change to generic/285
reduced the preallocated file size to smaller than 64k.

Cc: stable@vger.kernel.org # v3.7+
Signed-off-by: Eryu Guan <eguan@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-05-25 09:42:25 -07:00
Fabian Frederick 93407472a2 fs: add i_blocksize()
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>
2017-02-27 18:43:46 -08:00
Dave Jiang c791ace1e7 mm: replace FAULT_FLAG_SIZE with parameter to huge_fault
Since the introduction of FAULT_FLAG_SIZE to the vm_fault flag, it has
been somewhat painful with getting the flags set and removed at the
correct locations.  More than one kernel oops was introduced due to
difficulties of getting the placement correctly.

Remove the flag values and introduce an input parameter to huge_fault
that indicates the size of the page entry.  This makes the code easier
to trace and should avoid the issues we see with the fault flags where
removal of the flag was necessary in the fallback paths.

Link: http://lkml.kernel.org/r/148615748258.43180.1690152053774975329.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Tested-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:54 -08:00
Dave Jiang a2d581675d mm,fs,dax: change ->pmd_fault to ->huge_fault
Patch series "1G transparent hugepage support for device dax", v2.

The following series implements support for 1G trasparent hugepage on
x86 for device dax.  The bulk of the code was written by Mathew Wilcox a
while back supporting transparent 1G hugepage for fs DAX.  I have
forward ported the relevant bits to 4.10-rc.  The current submission has
only the necessary code to support device DAX.

Comments from Dan Williams: So the motivation and intended user of this
functionality mirrors the motivation and users of 1GB page support in
hugetlbfs.  Given expected capacities of persistent memory devices an
in-memory database may want to reduce tlb pressure beyond what they can
already achieve with 2MB mappings of a device-dax file.  We have
customer feedback to that effect as Willy mentioned in his previous
version of these patches [1].

[1]: https://lkml.org/lkml/2016/1/31/52

Comments from Nilesh @ Oracle:

There are applications which have a process model; and if you assume
10,000 processes attempting to mmap all the 6TB memory available on a
server; we are looking at the following:

processes         : 10,000
memory            :    6TB
pte @ 4k page size: 8 bytes / 4K of memory * #processes = 6TB / 4k * 8 * 10000 = 1.5GB * 80000 = 120,000GB
pmd @ 2M page size: 120,000 / 512 = ~240GB
pud @ 1G page size: 240GB / 512 = ~480MB

As you can see with 2M pages, this system will use up an exorbitant
amount of DRAM to hold the page tables; but the 1G pages finally brings
it down to a reasonable level.  Memory sizes will keep increasing; so
this number will keep increasing.

An argument can be made to convert the applications from process model
to thread model, but in the real world that may not be always practical.
Hopefully this helps explain the use case where this is valuable.

This patch (of 3):

In preparation for adding the ability to handle PUD pages, convert
vm_operations_struct.pmd_fault to vm_operations_struct.huge_fault.  The
vm_fault structure is extended to include a union of the different page
table pointers that may be needed, and three flag bits are reserved to
indicate which type of pointer is in the union.

[ross.zwisler@linux.intel.com: remove unused function ext4_dax_huge_fault()]
  Link: http://lkml.kernel.org/r/1485813172-7284-1-git-send-email-ross.zwisler@linux.intel.com
[dave.jiang@intel.com: clear PMD or PUD size flags when in fall through path]
  Link: http://lkml.kernel.org/r/148589842696.5820.16078080610311444794.stgit@djiang5-desk3.ch.intel.com
Link: http://lkml.kernel.org/r/148545058784.17912.6353162518188733642.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Jan Kara <jack@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Nilesh Choudhury <nilesh.choudhury@oracle.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:54 -08:00
Dave Jiang 11bac80004 mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmf
->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to
take a vma and vmf parameter when the vma already resides in vmf.

Remove the vma parameter to simplify things.

[arnd@arndb.de: fix ARM build]
  Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de
Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-24 17:46:54 -08:00
Linus Torvalds bc49a7831b Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:
 "142 patches:

   - DAX updates

   - various misc bits

   - OCFS2 updates

   - most of MM"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (142 commits)
  mm/z3fold.c: limit first_num to the actual range of possible buddy indexes
  mm: fix <linux/pagemap.h> stray kernel-doc notation
  zram: remove obsolete sysfs attrs
  mm/memblock.c: remove unnecessary log and clean up
  oom-reaper: use madvise_dontneed() logic to decide if unmap the VMA
  mm: drop unused argument of zap_page_range()
  mm: drop zap_details::check_swap_entries
  mm: drop zap_details::ignore_dirty
  mm, page_alloc: warn_alloc nodemask is NULL when cpusets are disabled
  mm: help __GFP_NOFAIL allocations which do not trigger OOM killer
  mm, oom: do not enforce OOM killer for __GFP_NOFAIL automatically
  mm: consolidate GFP_NOFAIL checks in the allocator slowpath
  lib/show_mem.c: teach show_mem to work with the given nodemask
  arch, mm: remove arch specific show_mem
  mm, page_alloc: warn_alloc print nodemask
  mm, page_alloc: do not report all nodes in show_mem
  Revert "mm: bail out in shrink_inactive_list()"
  mm, vmscan: consider eligible zones in get_scan_count
  mm, vmscan: cleanup lru size claculations
  mm, vmscan: do not count freed pages as PGDEACTIVATE
  ...
2017-02-22 19:29:24 -08:00
Dave Jiang f42003917b mm, dax: change pmd_fault() to take only vmf parameter
pmd_fault() and related functions really only need the vmf parameter since
the additional parameters are all included in the vmf struct.  Remove the
additional parameter and simplify pmd_fault() and friends.

Link: http://lkml.kernel.org/r/1484085142-2297-8-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22 16:41:26 -08:00
Dave Jiang d8a849e1bc mm, dax: make pmd_fault() and friends be the same as fault()
Instead of passing in multiple parameters in the pmd_fault() handler,
a vmf can be passed in just like a fault() handler. This will simplify
code and remove the need for the actual pmd fault handlers to allocate a
vmf. Related functions are also modified to do the same.

[dave.jiang@intel.com: fix issue with xfs_tests stall when DAX option is off]
  Link: http://lkml.kernel.org/r/148469861071.195597.3619476895250028518.stgit@djiang5-desk3.ch.intel.com
Link: http://lkml.kernel.org/r/1484085142-2297-7-git-send-email-ross.zwisler@linux.intel.com
Signed-off-by: Dave Jiang <dave.jiang@intel.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-02-22 16:41:26 -08:00
Christoph Hellwig 3c68d44a2b xfs: allocate direct I/O COW blocks in iomap_begin
Instead of preallocating all the required COW blocks in the high-level
write code do it inside the iomap code, like we do for all other I/O.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-02-06 17:47:47 -08:00
Christoph Hellwig 54a4ef8af4 xfs: reject all unaligned direct writes to reflinked files
We currently fall back from direct to buffered writes if we detect a
remaining shared extent in the iomap_begin callback.  But by the time
iomap_begin is called for the potentially unaligned end block we might
have already written most of the data to disk, which we'd now write
again using buffered I/O.  To avoid this reject all writes to reflinked
files before starting I/O so that we are guaranteed to only write the
data once.

The alternative would be to unshare the unaligned start and/or end block
before doing the I/O. I think that's doable, and will actually be
required to support reflinks on DAX file system.  But it will take a
little more time and I'd rather get rid of the double write ASAP.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-02-06 17:47:46 -08:00
Darrick J. Wong 7a652bbe36 xfs: fail _dir_open when readahead fails
When we open a directory, we try to readahead block 0 of the directory
on the assumption that we're going to need it soon.  If the bmbt is
corrupt, the directory will never be usable and the readahead fails
immediately, so we might as well prevent the directory from being opened
at all.  This prevents a subsequent read or modify operation from
hitting it and taking the fs offline.

NOTE: We're only checking for early failures in the block mapping, not
the readahead directory block itself.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-02-02 15:13:58 -08:00
Brian Foster c3155097ad xfs: sync eofblocks scans under iolock are livelock prone
The xfs_eofblocks.eof_scan_owner field is an internal field to
facilitate invoking eofb scans from the kernel while under the iolock.
This is necessary because the eofb scan acquires the iolock of each
inode. Synchronous scans are invoked on certain buffered write failures
while under iolock. In such cases, the scan owner indicates that the
context for the scan already owns the particular iolock and prevents a
double lock deadlock.

eofblocks scans while under iolock are still livelock prone in the event
of multiple parallel scans, however. If multiple buffered writes to
different inodes fail and invoke eofblocks scans at the same time, each
scan avoids a deadlock with its own inode by virtue of the
eof_scan_owner field, but will never be able to acquire the iolock of
the inode from the parallel scan. Because the low free space scans are
invoked with SYNC_WAIT, the scan will not return until it has processed
every tagged inode and thus both scans will spin indefinitely on the
iolock being held across the opposite scan. This problem can be
reproduced reliably by generic/224 on systems with higher cpu counts
(x16).

To avoid this problem, simplify the semantics of eofblocks scans to
never invoke a scan while under iolock. This means that the buffered
write context must drop the iolock before the scan. It must reacquire
the lock before the write retry and also repeat the initial write
checks, as the original state might no longer be valid once the iolock
was dropped.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-30 16:32:25 -08:00
Linus Torvalds 0110c350c8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "In this pile:

   - autofs-namespace series
   - dedupe stuff
   - more struct path constification"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (40 commits)
  ocfs2: implement the VFS clone_range, copy_range, and dedupe_range features
  ocfs2: charge quota for reflinked blocks
  ocfs2: fix bad pointer cast
  ocfs2: always unlock when completing dio writes
  ocfs2: don't eat io errors during _dio_end_io_write
  ocfs2: budget for extent tree splits when adding refcount flag
  ocfs2: prohibit refcounted swapfiles
  ocfs2: add newlines to some error messages
  ocfs2: convert inode refcount test to a helper
  simple_write_end(): don't zero in short copy into uptodate
  exofs: don't mess with simple_write_{begin,end}
  9p: saner ->write_end() on failing copy into non-uptodate page
  fix gfs2_stuffed_write_end() on short copies
  fix ceph_write_end()
  nfs_write_end(): fix handling of short copies
  vfs: refactor clone/dedupe_file_range common functions
  fs: try to clone files first in vfs_copy_file_range
  vfs: misc struct path constification
  namespace.c: constify struct path passed to a bunch of primitives
  quota: constify struct path in quota_on
  ...
2016-12-17 18:44:00 -08:00
Christoph Hellwig a76b5b0437 fs: try to clone files first in vfs_copy_file_range
A clone is a perfectly fine implementation of a file copy, so most
file systems just implement the copy that way.  Instead of duplicating
this logic move it to the VFS.  Currently btrfs and XFS implement copies
the same way as clones and there is no behavior change for them, cifs
only implements clones and grow support for copy_file_range with this
patch.  NFS implements both, so this will allow copy_file_range to work
on servers that only implement CLONE and be lot more efficient on servers
that implements CLONE and COPY.

Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-12-09 16:17:19 -08:00
Dave Chinner 9807b773da Merge branch 'xfs-4.10-misc-fixes-4' into for-next 2016-12-09 16:56:26 +11:00
Dave Chinner 2291dab2c9 xfs: Always flush caches when integrity is required
There is no reason anymore for not issuing device integrity
operations when teh filesystem requires ordering or data integrity
guarantees. We should always issue cache flushes and FUA writes
where necessary and let the underlying storage optimise them as
necessary for correct integrity operation.

Signed-Off-By: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-09 16:49:54 +11:00
Dave Chinner a444d72e60 Merge branch 'xfs-4.10-misc-fixes-3' into for-next 2016-12-07 17:42:30 +11:00
Darrick J. Wong 1bb33a9870 xfs: don't cap maximum dedupe request length
After various discussions on linux-fsdevel, it has been decided that it
is not necessary to cap the length of a dedupe request, and that
correctly-written userspace client programs will be able to absorb the
change.  Therefore, remove the length clamping behavior.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-05 12:38:57 +11:00
Christoph Hellwig acdda3aae1 xfs: use iomap_dio_rw
Straight switch over to using iomap for direct I/O - we already have the
non-COW dio path in write_begin for DAX and files with extent size hints,
so nothing to add there.  The COW path is ported over from the old
get_blocks version and a bit of a mess, but I have some work in progress
to make it look more like the buffered I/O COW path.

This gets rid of xfs_get_blocks_direct and the last caller of
xfs_get_blocks with the create flag set, so all that code can be removed.

Last but not least I've removed a comment in xfs_filemap_fault that
refers to xfs_get_blocks entirely instead of updating it - while the
reference is correct, the whole DAX fault path looks different than
the non-DAX one, so it seems rather pointless.

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>
2016-11-30 14:37:15 +11:00
Christoph Hellwig 6552321831 xfs: remove i_iolock and use i_rwsem in the VFS inode instead
This patch drops the XFS-own i_iolock and uses the VFS i_rwsem which
recently replaced i_mutex instead.  This means we only have to take
one lock instead of two in many fast path operations, and we can
also shrink the xfs_inode structure.  Thanks to the xfs_ilock family
there is very little churn, the only thing of note is that we need
to switch to use the lock_two_directory helper for taking the i_rwsem
on two inodes in a few places to make sure our lock order matches
the one used in the VFS.

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>
2016-11-30 14:33:25 +11:00
Dave Chinner e3df41f978 Merge branch 'xfs-4.10-misc-fixes-2' into iomap-4.10-directio 2016-11-30 12:49:38 +11:00
Ross Zwisler 862f1b9d67 xfs: use struct iomap based DAX PMD fault path
Switch xfs_filemap_pmd_fault() from using dax_pmd_fault() to the new and
improved dax_iomap_pmd_fault().  Also, now that it has no more users,
remove xfs_get_blocks_dax_fault().

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-08 11:35:02 +11:00
Ross Zwisler 11c59c92f4 dax: correct dax iomap code namespace
The recently added DAX functions that use the new struct iomap data
structure were named iomap_dax_rw(), iomap_dax_fault() and
iomap_dax_actor().  These are actually defined in fs/dax.c, though, so
should be part of the "dax" namespace and not the "iomap" namespace.
Rename them to dax_iomap_rw(), dax_iomap_fault() and dax_iomap_actor()
respectively.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Suggested-by: Dave Chinner <david@fromorbit.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-11-08 11:32:46 +11:00
Christoph Hellwig 5faaf4fa0a xfs: merge xfs_reflink_remap_range and xfs_file_share_range
There is no clear division of responsibility between those functions, so
just merge them into one to keep the code simple.  Also move
xfs_file_wait_for_io to xfs_reflink.c together with its only caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20 15:50:07 +11:00
Christoph Hellwig ec40759902 xfs: remove xfs_file_wait_for_io
filemap_write_and_wait_range operates on full pages, so there is no
need for the rounding operations.  Additionally this allows us to
micro-optimize by skipping the second inode_dio_wait for a
intra-file clone.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20 15:49:55 +11:00
Christoph Hellwig 576177818e xfs: move inode locking from xfs_reflink_remap_range to xfs_file_share_range
We need the iolock protection to stabilizie the IS_SWAPFILE and
IS_IMMUTABLE values, as well as preventing new buffered writers
re-dirtying the file data that we just wrote out.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20 15:49:19 +11:00
Christoph Hellwig a62e82b35b xfs: fix the same_inode check in xfs_file_share_range
The VFS i_ino is an unsigned long, while XFS inode numbers are 64-bit
wide, so checking i_ino for equality could lead to rate false positives
on 32-bit architectures.  Just compare the inode pointers themselves
to be safe.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20 15:49:03 +11:00
Christoph Hellwig 4fbc2c6525 xfs: remove the same fs check from xfs_file_share_range
The VFS already does the check, and the placement of this duplicate
is in the way of the following locking rework.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20 15:48:54 +11:00
Christoph Hellwig 0ee7a3f6b5 xfs: don't take the IOLOCK exclusive for direct I/O page invalidation
XFS historically took the iolock exclusive when invalidating pages
before direct I/O operations to protect against writeback starvations.

But this writeback starvation issues has been fixed a long time ago
in the core writeback code, and all other file systems manage to do
without the exclusive lock.  Convert XFS over to avoid the exclusive
lock in this case, and also move to range invalidations like done
by the other file systems.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-20 15:44:14 +11:00
Linus Torvalds 35a891be96 xfs: reflink update for 4.9-rc1
< XFS has gained super CoW powers! >
  ----------------------------------
         \   ^__^
          \  (oo)\_______
             (__)\       )\/\
                 ||----w |
                 ||     ||
 
 Included in this update:
 - unshare range (FALLOC_FL_UNSHARE) support for fallocate
 - copy-on-write extent size hints (FS_XFLAG_COWEXTSIZE) for fsxattr interface
 - shared extent support for XFS
 - copy-on-write support for shared extents
 - copy_file_range support
 - clone_file_range support (implements reflink)
 - dedupe_file_range support
 - defrag support for reverse mapping enabled filesystems
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Merge tag 'xfs-reflink-for-linus-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

    < XFS has gained super CoW powers! >
     ----------------------------------
            \   ^__^
             \  (oo)\_______
                (__)\       )\/\
                    ||----w |
                    ||     ||

Pull XFS support for shared data extents from Dave Chinner:
 "This is the second part of the XFS updates for this merge cycle.  This
  pullreq contains the new shared data extents feature for XFS.

  Given the complexity and size of this change I am expecting - like the
  addition of reverse mapping last cycle - that there will be some
  follow-up bug fixes and cleanups around the -rc3 stage for issues that
  I'm sure will show up once the code hits a wider userbase.

  What it is:

  At the most basic level we are simply adding shared data extents to
  XFS - i.e. a single extent on disk can now have multiple owners. To do
  this we have to add new on-disk features to both track the shared
  extents and the number of times they've been shared. This is done by
  the new "refcount" btree that sits in every allocation group. When we
  share or unshare an extent, this tree gets updated.

  Along with this new tree, the reverse mapping tree needs to be updated
  to track each owner or a shared extent. This also needs to be updated
  ever share/unshare operation. These interactions at extent allocation
  and freeing time have complex ordering and recovery constraints, so
  there's a significant amount of new intent-based transaction code to
  ensure that operations are performed atomically from both the runtime
  and integrity/crash recovery perspectives.

  We also need to break sharing when writes hit a shared extent - this
  is where the new copy-on-write implementation comes in. We allocate
  new storage and copy the original data along with the overwrite data
  into the new location. We only do this for data as we don't share
  metadata at all - each inode has it's own metadata that tracks the
  shared data extents, the extents undergoing CoW and it's own private
  extents.

  Of course, being XFS, nothing is simple - we use delayed allocation
  for CoW similar to how we use it for normal writes. ENOSPC is a
  significant issue here - we build on the reservation code added in
  4.8-rc1 with the reverse mapping feature to ensure we don't get
  spurious ENOSPC issues part way through a CoW operation. These
  mechanisms also help minimise fragmentation due to repeated CoW
  operations. To further reduce fragmentation overhead, we've also
  introduced a CoW extent size hint, which indicates how large a region
  we should allocate when we execute a CoW operation.

  With all this functionality in place, we can hook up .copy_file_range,
  .clone_file_range and .dedupe_file_range and we gain all the
  capabilities of reflink and other vfs provided functionality that
  enable manipulation to shared extents. We also added a fallocate mode
  that explicitly unshares a range of a file, which we implemented as an
  explicit CoW of all the shared extents in a file.

  As such, it's a huge chunk of new functionality with new on-disk
  format features and internal infrastructure. It warns at mount time as
  an experimental feature and that it may eat data (as we do with all
  new on-disk features until they stabilise). We have not released
  userspace suport for it yet - userspace support currently requires
  download from Darrick's xfsprogs repo and build from source, so the
  access to this feature is really developer/tester only at this point.
  Initial userspace support will be released at the same time the kernel
  with this code in it is released.

  The new code causes 5-6 new failures with xfstests - these aren't
  serious functional failures but things the output of tests changing
  slightly due to perturbations in layouts, space usage, etc. OTOH,
  we've added 150+ new tests to xfstests that specifically exercise this
  new functionality so it's got far better test coverage than any
  functionality we've previously added to XFS.

  Darrick has done a pretty amazing job getting us to this stage, and
  special mention also needs to go to Christoph (review, testing,
  improvements and bug fixes) and Brian (caught several intricate bugs
  during review) for the effort they've also put in.

  Summary:

   - unshare range (FALLOC_FL_UNSHARE) support for fallocate

   - copy-on-write extent size hints (FS_XFLAG_COWEXTSIZE) for fsxattr
     interface

   - shared extent support for XFS

   - copy-on-write support for shared extents

   - copy_file_range support

   - clone_file_range support (implements reflink)

   - dedupe_file_range support

   - defrag support for reverse mapping enabled filesystems"

* tag 'xfs-reflink-for-linus-4.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (71 commits)
  xfs: convert COW blocks to real blocks before unwritten extent conversion
  xfs: rework refcount cow recovery error handling
  xfs: clear reflink flag if setting realtime flag
  xfs: fix error initialization
  xfs: fix label inaccuracies
  xfs: remove isize check from unshare operation
  xfs: reduce stack usage of _reflink_clear_inode_flag
  xfs: check inode reflink flag before calling reflink functions
  xfs: implement swapext for rmap filesystems
  xfs: refactor swapext code
  xfs: various swapext cleanups
  xfs: recognize the reflink feature bit
  xfs: simulate per-AG reservations being critically low
  xfs: don't mix reflink and DAX mode for now
  xfs: check for invalid inode reflink flags
  xfs: set a default CoW extent size of 32 blocks
  xfs: convert unwritten status of reverse mappings for shared files
  xfs: use interval query for rmap alloc operations on shared files
  xfs: add shared rmap map/unmap/convert log item types
  xfs: increase log reservations for reflink
  ...
2016-10-13 20:28:22 -07:00
Linus Torvalds fed41f7d03 Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull splice fixups from Al Viro:
 "A couple of fixups for interaction of pipe-backed iov_iter with
  O_DIRECT reads + constification of a couple of primitives in uio.h
  missed by previous rounds.

  Kudos to davej - his fuzzing has caught those bugs"

* 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  [btrfs] fix check_direct_IO() for non-iovec iterators
  constify iov_iter_count() and iter_is_iovec()
  fix ITER_PIPE interaction with direct_IO
2016-10-10 13:38:49 -07:00
Linus Torvalds abb5a14fa2 Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs updates from Al Viro:
 "Assorted misc bits and pieces.

  There are several single-topic branches left after this (rename2
  series from Miklos, current_time series from Deepa Dinamani, xattr
  series from Andreas, uaccess stuff from from me) and I'd prefer to
  send those separately"

* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits)
  proc: switch auxv to use of __mem_open()
  hpfs: support FIEMAP
  cifs: get rid of unused arguments of CIFSSMBWrite()
  posix_acl: uapi header split
  posix_acl: xattr representation cleanups
  fs/aio.c: eliminate redundant loads in put_aio_ring_file
  fs/internal.h: add const to ns_dentry_operations declaration
  compat: remove compat_printk()
  fs/buffer.c: make __getblk_slow() static
  proc: unsigned file descriptors
  fs/file: more unsigned file descriptors
  fs: compat: remove redundant check of nr_segs
  cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]
  cifs: don't use memcpy() to copy struct iov_iter
  get rid of separate multipage fault-in primitives
  fs: Avoid premature clearing of capabilities
  fs: Give dentry to inode_change_ok() instead of inode
  fuse: Propagate dentry down to inode_change_ok()
  ceph: Propagate dentry down to inode_change_ok()
  xfs: Propagate dentry down to inode_change_ok()
  ...
2016-10-10 13:04:49 -07:00
Al Viro c3a6902404 fix ITER_PIPE interaction with direct_IO
by making sure we call iov_iter_advance() on original
iov_iter even if direct_IO (done on its copy) has returned 0.
It's a no-op for old iov_iter flavours and does the right thing
(== truncation of the stuff we'd allocated, but not filled) in
ITER_PIPE case.  Failures (e.g. -EIO) get caught and dealt with
by cleanup in generic_file_read_iter().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-10 13:36:06 -04:00
Darrick J. Wong 93fed47013 xfs: fix label inaccuracies
Since we don't unlock anything on the way out, change the label.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reported-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-10 16:49:10 +11:00
Al Viro e55f1d1d13 Merge remote-tracking branch 'jk/vfs' into work.misc 2016-10-08 11:06:08 -04:00
Linus Torvalds b66484cd74 Merge branch 'akpm' (patches from Andrew)
Merge updates from Andrew Morton:

 - fsnotify updates

 - ocfs2 updates

 - all of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits)
  console: don't prefer first registered if DT specifies stdout-path
  cred: simpler, 1D supplementary groups
  CREDITS: update Pavel's information, add GPG key, remove snail mail address
  mailmap: add Johan Hovold
  .gitattributes: set git diff driver for C source code files
  uprobes: remove function declarations from arch/{mips,s390}
  spelling.txt: "modeled" is spelt correctly
  nmi_backtrace: generate one-line reports for idle cpus
  arch/tile: adopt the new nmi_backtrace framework
  nmi_backtrace: do a local dump_stack() instead of a self-NMI
  nmi_backtrace: add more trigger_*_cpu_backtrace() methods
  min/max: remove sparse warnings when they're nested
  Documentation/filesystems/proc.txt: add more description for maps/smaps
  mm, proc: fix region lost in /proc/self/smaps
  proc: fix timerslack_ns CAP_SYS_NICE check when adjusting self
  proc: add LSM hook checks to /proc/<tid>/timerslack_ns
  proc: relax /proc/<tid>/timerslack_ns capability requirements
  meminfo: break apart a very long seq_printf with #ifdefs
  seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char
  proc: faster /proc/*/status
  ...
2016-10-07 21:38:00 -07:00
Toshi Kani dbe6ec8156 ext2/4, xfs: call thp_get_unmapped_area() for pmd mappings
To support DAX pmd mappings with unmodified applications, filesystems
need to align an mmap address by the pmd size.

Call thp_get_unmapped_area() from f_op->get_unmapped_area.

Note, there is no change in behavior for a non-DAX file.

Link: http://lkml.kernel.org/r/1472497881-9323-3-git-send-email-toshi.kani@hpe.com
Signed-off-by: Toshi Kani <toshi.kani@hpe.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-10-07 18:46:28 -07:00
Linus Torvalds d1f5323370 Merge branch 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull VFS splice updates from Al Viro:
 "There's a bunch of branches this cycle, both mine and from other folks
  and I'd rather send pull requests separately.

  This one is the conversion of ->splice_read() to ITER_PIPE iov_iter
  (and introduction of such). Gets rid of a lot of code in fs/splice.c
  and elsewhere; there will be followups, but these are for the next
  cycle...  Some pipe/splice-related cleanups from Miklos in the same
  branch as well"

* 'work.splice_read' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  pipe: fix comment in pipe_buf_operations
  pipe: add pipe_buf_steal() helper
  pipe: add pipe_buf_confirm() helper
  pipe: add pipe_buf_release() helper
  pipe: add pipe_buf_get() helper
  relay: simplify relay_file_read()
  switch default_file_splice_read() to use of pipe-backed iov_iter
  switch generic_file_splice_read() to use of ->read_iter()
  new iov_iter flavour: pipe-backed
  fuse_dev_splice_read(): switch to add_to_pipe()
  skb_splice_bits(): get rid of callback
  new helper: add_to_pipe()
  splice: lift pipe_lock out of splice_to_pipe()
  splice: switch get_iovec_page_array() to iov_iter
  splice_to_pipe(): don't open-code wakeup_pipe_readers()
  consistent treatment of EFAULT on O_DIRECT read/write
2016-10-07 15:36:58 -07:00
Darrick J. Wong 4f435ebe7d xfs: don't mix reflink and DAX mode for now
Since we don't have a strategy for handling both DAX and reflink,
for now we'll just prohibit both being set at the same time.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-05 16:26:31 -07:00
Darrick J. Wong 83104d449e xfs: garbage collect old cowextsz reservations
Trim CoW reservations made on behalf of a cowextsz hint if they get too
old or we run low on quota, so long as we don't have dirty data awaiting
writeback or directio operations in progress.

Garbage collection of the cowextsize extents are kept separate from
prealloc extent reaping because setting the CoW prealloc lifetime to a
(much) higher value than the regular prealloc extent lifetime has been
useful for combatting CoW fragmentation on VM hosts where the VMs
experience bursty write behaviors and we can keep the utilization ratios
low enough that we don't start to run out of space.  IOWs, it benefits
us to keep the CoW fork reservations around for as long as we can unless
we run out of blocks or hit inode reclaim.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-05 16:26:28 -07:00
Darrick J. Wong 98cc2db5b8 xfs: unshare a range of blocks via fallocate
Unshare all shared extents if the user calls fallocate with the new
unshare mode flag set, so that we can guarantee that a subsequent
write will not ENOSPC.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[hch: pass inode instead of file to xfs_reflink_dirty_range,
      use iomap infrastructure for copy up]
Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-10-05 16:26:26 -07:00
Darrick J. Wong cc714660bb xfs: add dedupe range vfs function
Define a VFS function which allows userspace to request that the
kernel reflink a range of blocks between two files if the ranges'
contents match.  The function fits the new VFS ioctl that standardizes
the checking for the btrfs EXTENT SAME ioctl.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-05 16:26:26 -07:00
Darrick J. Wong 9fe26045e9 xfs: add clone file and clone range vfs functions
Define two VFS functions which allow userspace to reflink a range of
blocks between two files or to reflink one file's contents to another.
These functions fit the new VFS ioctls that standardize the checking
for the btrfs CLONE and CLONE RANGE ioctls.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-05 16:26:25 -07:00
Darrick J. Wong 0613f16cd2 xfs: implement CoW for directio writes
For O_DIRECT writes to shared blocks, we have to CoW them just like
we would with buffered writes.  For writes that are not block-aligned,
just bounce them to the page cache.

For block-aligned writes, however, we can do better than that.  Use
the same mechanisms that we employ for buffered CoW to set up a
delalloc reservation, allocate all the blocks at once, issue the
writes against the new blocks and use the same ioend functions to
remap the blocks after the write.  This should be fairly performant.

Christoph discovered that xfs_reflink_allocate_cow_range may stumble
over invalid entries in the extent array given that it drops the ilock
but still expects the index to be stable.  Simple fixing it to a new
lookup for every iteration still isn't correct given that
xfs_bmapi_allocate will trigger a BUG_ON() if hitting a hole, and
there is nothing preventing a xfs_bunmapi_cow call removing extents
once we dropped the ilock either.

This patch duplicates the inner loop of xfs_bmapi_allocate into a
helper for xfs_reflink_allocate_cow_range so that it can be done under
the same ilock critical section as our CoW fork delayed allocation.
The directio CoW warts will be revisited in a later patch.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-10-05 16:26:04 -07:00
Al Viro 82c156f853 switch generic_file_splice_read() to use of ->read_iter()
... and kill the ->splice_read() instances that can be switched to it

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-05 18:23:56 -04:00
Dave Chinner a1f45e668e Merge branch 'iomap-4.9-dax' into for-next 2016-10-03 09:53:59 +11:00
Christoph Hellwig a447d7cd15 xfs: update atime before I/O in xfs_file_dio_aio_read
After the call to __blkdev_direct_IO the final reference to the file
might have been dropped by aio_complete already, and the call to
file_accessed might cause a use after free.

Instead update the access time before the I/O, similar to how we
update the time stamps before writes.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-and-tested-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-03 09:47:34 +11:00
Jan Kara 69bca80744 xfs: Propagate dentry down to inode_change_ok()
To avoid clearing of capabilities or security related extended
attributes too early, inode_change_ok() will need to take dentry instead
of inode. Propagate dentry down to functions calling inode_change_ok().
This is rather straightforward except for xfs_set_mode() function which
does not have dentry easily available. Luckily that function does not
call inode_change_ok() anyway so we just have to do a little dance with
function prototypes.

Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
2016-09-22 10:56:19 +02:00
Christoph Hellwig 6c31f495d1 xfs: use iomap to implement DAX
Another users of buffer_heads bytes the dust.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:28:38 +10:00
Christoph Hellwig 17879e8f86 xfs: fix locking for DAX writes
So far DAX writes inherited the locking from direct I/O writes, but
the direct I/O model of using shared locks for writes is actually
wrong for DAX.  For direct I/O we're out of any standards and don't
have to provide the Posix required exclusion between writers, but
for DAX which gets transparently enable on applications without any
knowledge of it we can't simply drop the requirement.  Even worse
this only happens for aligned writes and thus doesn't show up for
many typical use cases.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-09-19 11:24:50 +10:00
Dave Chinner 8b2180b3bf xfs: don't invalidate whole file on DAX read/write
When we do DAX IO, we try to invalidate the entire page cache held
on the file. This is incorrect as it will trash the entire mapping
tree that now tracks dirty state in exceptional entries in the radix
tree slots.

What we are trying to do is remove cached pages (e.g from reads
into holes) that sit in the radix tree over the range we are about
to write to. Hence we should just limit the invalidation to the
range we are about to overwrite.

Reported-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-17 08:31:33 +10:00
Linus Torvalds 0e6acf0204 xfs: update for 4.8-rc1
Changes in this update:
 o generic iomap based IO path infrastructure
 o generic iomap based fiemap implementation
 o xfs iomap based Io path implementation
 o buffer error handling fixes
 o tracking of in flight buffer IO for unmount serialisation
 o direct IO and DAX io path separation and simplification
 o shortform directory format definition changes for wider platform compatibility
 o various buffer cache fixes
 o cleanups in preparation for rmap merge
 o error injection cleanups and fixes
 o log item format buffer memory allocation restructuring to prevent rare OOM
   reclaim deadlocks
 o sparse inode chunks are now fully supported.
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Merge tag 'xfs-for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull xfs updates from Dave Chinner:
 "The major addition is the new iomap based block mapping
  infrastructure.  We've been kicking this about locally for years, but
  there are other filesystems want to use it too (e.g. gfs2).  Now it
  is fully working, reviewed and ready for merge and be used by other
  filesystems.

  There are a lot of other fixes and cleanups in the tree, but those are
  XFS internal things and none are of the scale or visibility of the
  iomap changes.  See below for details.

  I am likely to send another pull request next week - we're just about
  ready to merge some new functionality (on disk block->owner reverse
  mapping infrastructure), but that's a huge chunk of code (74 files
  changed, 7283 insertions(+), 1114 deletions(-)) so I'm keeping that
  separate to all the "normal" pull request changes so they don't get
  lost in the noise.

  Summary of changes in this update:
   - generic iomap based IO path infrastructure
   - generic iomap based fiemap implementation
   - xfs iomap based Io path implementation
   - buffer error handling fixes
   - tracking of in flight buffer IO for unmount serialisation
   - direct IO and DAX io path separation and simplification
   - shortform directory format definition changes for wider platform
     compatibility
   - various buffer cache fixes
   - cleanups in preparation for rmap merge
   - error injection cleanups and fixes
   - log item format buffer memory allocation restructuring to prevent
     rare OOM reclaim deadlocks
   - sparse inode chunks are now fully supported"

* tag 'xfs-for-linus-4.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (53 commits)
  xfs: remove EXPERIMENTAL tag from sparse inode feature
  xfs: bufferhead chains are invalid after end_page_writeback
  xfs: allocate log vector buffers outside CIL context lock
  libxfs: directory node splitting does not have an extra block
  xfs: remove dax code from object file when disabled
  xfs: skip dirty pages in ->releasepage()
  xfs: remove __arch_pack
  xfs: kill xfs_dir2_inou_t
  xfs: kill xfs_dir2_sf_off_t
  xfs: split direct I/O and DAX path
  xfs: direct calls in the direct I/O path
  xfs: stop using generic_file_read_iter for direct I/O
  xfs: split xfs_file_read_iter into buffered and direct I/O helpers
  xfs: remove s_maxbytes enforcement in xfs_file_read_iter
  xfs: kill ioflags
  xfs: don't pass ioflags around in the ioctl path
  xfs: track and serialize in-flight async buffers against unmount
  xfs: exclude never-released buffers from buftarg I/O accounting
  xfs: don't reset b_retries to 0 on every failure
  xfs: remove extraneous buffer flag changes
  ...
2016-07-27 09:53:35 -07:00
Ross Zwisler 6b524995a7 dax: remote unused fault wrappers
Remove the unused wrappers dax_fault() and dax_pmd_fault().  After this
removal, rename __dax_fault() and __dax_pmd_fault() to dax_fault() and
dax_pmd_fault() respectively, and update all callers.

The dax_fault() and dax_pmd_fault() wrappers were initially intended to
capture some filesystem independent functionality around page faults
(calling sb_start_pagefault() & sb_end_pagefault(), updating file mtime
and ctime).

However, the following commits:

   5726b27b09 ("ext2: Add locking for DAX faults")
   ea3d7209ca ("ext4: fix races between page faults and hole punching")

added locking to the ext2 and ext4 filesystems after these common
operations but before __dax_fault() and __dax_pmd_fault() were called.
This means that these wrappers are no longer used, and are unlikely to
be used in the future.

XFS has had locking analogous to what was recently added to ext2 and
ext4 since DAX support was initially introduced by:

   6b698edeee ("xfs: add DAX file operations support")

Link: http://lkml.kernel.org/r/20160714214049.20075-2-ross.zwisler@linux.intel.com
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-26 16:19:19 -07:00
Dave Chinner f2bdfda9a1 Merge branch 'xfs-4.8-misc-fixes-4' into for-next 2016-07-22 14:10:56 +10:00
Arnd Bergmann f021bd071f xfs: remove dax code from object file when disabled
We check IS_DAX(inode) before calling either xfs_file_dax_read or
xfs_file_dax_write, and this will lead the call being optimized out at
compile time when CONFIG_FS_DAX is disabled.

However, the two functions are marked STATIC, so they become global
symbols when CONFIG_XFS_DEBUG is set, leaving us with two unused global
functions that call into an undefined function and a broken "allmodconfig"
build:

fs/built-in.o: In function `xfs_file_dax_read':
fs/xfs/xfs_file.c:348: undefined reference to `dax_do_io'
fs/built-in.o: In function `xfs_file_dax_write':
fs/xfs/xfs_file.c:758: undefined reference to `dax_do_io'

Marking the two functions 'static noinline' instead of 'STATIC' will let
the compiler drop the symbols when there are no callers but avoid the
implicit inlining.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Fixes: 16d4d43595 ("xfs: split direct I/O and DAX path")
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-22 09:50:55 +10:00
Dave Chinner b47ec80bfe Merge branch 'xfs-4.8-split-dax-dio' into for-next 2016-07-20 11:54:37 +10:00
Christoph Hellwig 16d4d43595 xfs: split direct I/O and DAX path
So far the DAX code overloaded the direct I/O code path.  There is very little
in common between the two, and untangling them allows to clean up both variants.

As a side effect we also get separate trace points for both I/O types.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:38:55 +10:00
Christoph Hellwig fa8d972d05 xfs: direct calls in the direct I/O path
We control both the callers and callees of ->direct_IO, so remove the
indirect calls.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:38:01 +10:00
Christoph Hellwig f1285ff0ac xfs: stop using generic_file_read_iter for direct I/O
XFS already implement it's own flushing of the pagecache because it
implements proper synchronization for direct I/O reads.  This means
calling generic_file_read_iter for direct I/O is rather useless,
as it doesn't do much but updating the atime and iocb position for
us.  This also gets rid of the buffered I/O fallback that isn't used
for XFS.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:36:57 +10:00
Christoph Hellwig bbc5a740c4 xfs: split xfs_file_read_iter into buffered and direct I/O helpers
Similar to what we did on the write side a while ago.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:35:42 +10:00
Christoph Hellwig cf810712cc xfs: remove s_maxbytes enforcement in xfs_file_read_iter
All the three low-level read implementations that we might call already
take care of not overflowing the maximum supported bytes, no need to
duplicate it here.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:31:53 +10:00
Christoph Hellwig 3176c3e0ef xfs: kill ioflags
Now that we have the direct I/O kiocb flag there is no real need to sample
the value inside of XFS, and the invis flag was always just partially used
and isn't worth keeping this infrastructure around for.   This also splits
the read tracepoint into buffered vs direct as we've done for writes a long
time ago.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-07-20 11:31:42 +10:00
Christoph Hellwig 570b6211b8 xfs: use xfs_zero_range in xfs_zero_eof
We now skip holes in it, so no need to have the caller do it as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-06-21 09:57:26 +10:00
Christoph Hellwig 7bb41db3ea xfs: handle 64-bit length in xfs_iozero
We'll want to use this code for large offsets now that we're
skipping holes and unwritten extents efficiently.  Also rename it to
xfs_zero_range to be a bit more descriptive, and tell the caller if
we actually did any zeroing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-06-21 09:56:26 +10:00
Christoph Hellwig 459f0fbc2a xfs: use iomap infrastructure for DAX zeroing
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-06-21 09:55:18 +10:00
Christoph Hellwig 68a9f5e700 xfs: implement iomap based buffered write path
Convert XFS to use the new iomap based multipage write path. This involves
implementing the ->iomap_begin and ->iomap_end methods, and switching the
buffered file write, page_mkwrite and xfs_iozero paths to the new iomap
helpers.

With this change __xfs_get_blocks will never be used for buffered writes,
and the code handling them can be removed.

Based on earlier code from Dave Chinner.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-06-21 09:53:44 +10:00
Linus Torvalds 315227f6da DAX error handling for 4.7
- Until now, dax has been disabled if media errors were found on
   any device. This enables the use of DAX in the presence of these
   errors by making all sector-aligned zeroing go through the driver.
 - The driver (already) has the ability to clear errors on writes that
   are sent through the block layer using 'DSMs' defined in ACPI 6.1.
 
 Other misc changes:
 
 - When mounting DAX filesystems, check to make sure the partition
   is page aligned. This is a requirement for DAX, and previously, we
   allowed such unaligned mounts to succeed, but subsequent reads/writes
   would fail.
 
 - Misc/cleanup fixes from Jan that remove unused code from DAX related to
   zeroing, writeback, and some size checks.
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Merge tag 'dax-misc-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm

Pull misc DAX updates from Vishal Verma:
 "DAX error handling for 4.7

   - Until now, dax has been disabled if media errors were found on any
     device.  This enables the use of DAX in the presence of these
     errors by making all sector-aligned zeroing go through the driver.

   - The driver (already) has the ability to clear errors on writes that
     are sent through the block layer using 'DSMs' defined in ACPI 6.1.

  Other misc changes:

   - When mounting DAX filesystems, check to make sure the partition is
     page aligned.  This is a requirement for DAX, and previously, we
     allowed such unaligned mounts to succeed, but subsequent
     reads/writes would fail.

   - Misc/cleanup fixes from Jan that remove unused code from DAX
     related to zeroing, writeback, and some size checks"

* tag 'dax-misc-for-4.7' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm:
  dax: fix a comment in dax_zero_page_range and dax_truncate_page
  dax: for truncate/hole-punch, do zeroing through the driver if possible
  dax: export a low-level __dax_zero_page_range helper
  dax: use sb_issue_zerout instead of calling dax_clear_sectors
  dax: enable dax in the presence of known media errors (badblocks)
  dax: fallback from pmd to pte on error
  block: Update blkdev_dax_capable() for consistency
  xfs: Add alignment check for DAX mount
  ext2: Add alignment check for DAX mount
  ext4: Add alignment check for DAX mount
  block: Add bdev_dax_supported() for dax mount checks
  block: Add vfs_msg() interface
  dax: Remove redundant inode size checks
  dax: Remove pointless writeback from dax_do_io()
  dax: Remove zeroing from dax_io()
  dax: Remove dead zeroing code from fault handlers
  ext2: Avoid DAX zeroing to corrupt data
  ext2: Fix block zeroing in ext2_get_blocks() for DAX
  dax: Remove complete_unwritten argument
  DAX: move RADIX_DAX_ definitions to dax.c
2016-05-26 19:34:26 -07:00
Linus Torvalds 0b9210c9c8 xfs: update for 4.7-rc1
Changes in this update:
 o fixes for mount line parsing, sparse warnings, read-only compat
   feature remount behaviour
 o allow fast path symlink lookups for inline symlinks.
 o attribute listing cleanups
 o writeback goes direct to bios rather than indirecting through
   bufferheads
 o transaction allocation cleanup
 o optimised kmem_realloc
 o added configurable error handling for metadata write errors,
   changed default error handling behaviour from "retry forever" to
   "retry until unmount then fail"
 o fixed several inode cluster writeback lookup vs reclaim race
   conditions
 o fixed inode cluster writeback checking wrong inode after lookup
 o fixed bugs where struct xfs_inode freeing wasn't actually RCU safe
 o cleaned up inode reclaim tagging
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Merge tag 'xfs-for-linus-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull xfs updates from Dave Chinner:
 "A pretty average collection of fixes, cleanups and improvements in
  this request.

  Summary:
   - fixes for mount line parsing, sparse warnings, read-only compat
     feature remount behaviour
   - allow fast path symlink lookups for inline symlinks.
   - attribute listing cleanups
   - writeback goes direct to bios rather than indirecting through
     bufferheads
   - transaction allocation cleanup
   - optimised kmem_realloc
   - added configurable error handling for metadata write errors,
     changed default error handling behaviour from "retry forever" to
     "retry until unmount then fail"
   - fixed several inode cluster writeback lookup vs reclaim race
     conditions
   - fixed inode cluster writeback checking wrong inode after lookup
   - fixed bugs where struct xfs_inode freeing wasn't actually RCU safe
   - cleaned up inode reclaim tagging"

* tag 'xfs-for-linus-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (39 commits)
  xfs: fix warning in xfs_finish_page_writeback for non-debug builds
  xfs: move reclaim tagging functions
  xfs: simplify inode reclaim tagging interfaces
  xfs: rename variables in xfs_iflush_cluster for clarity
  xfs: xfs_iflush_cluster has range issues
  xfs: mark reclaimed inodes invalid earlier
  xfs: xfs_inode_free() isn't RCU safe
  xfs: optimise xfs_iext_destroy
  xfs: skip stale inodes in xfs_iflush_cluster
  xfs: fix inode validity check in xfs_iflush_cluster
  xfs: xfs_iflush_cluster fails to abort on error
  xfs: remove xfs_fs_evict_inode()
  xfs: add "fail at unmount" error handling configuration
  xfs: add configuration handlers for specific errors
  xfs: add configuration of error failure speed
  xfs: introduce table-based init for error behaviors
  xfs: add configurable error support to metadata buffers
  xfs: introduce metadata IO error class
  xfs: configurable error behavior via sysfs
  xfs: buffer ->bi_end_io function requires irq-safe lock
  ...
2016-05-26 10:13:40 -07:00
Linus Torvalds c2e7b20705 Merge branch 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs cleanups from Al Viro:
 "More cleanups from Christoph"

* 'work.preadv2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  nfsd: use RWF_SYNC
  fs: add RWF_DSYNC aand RWF_SYNC
  ceph: use generic_write_sync
  fs: simplify the generic_write_sync prototype
  fs: add IOCB_SYNC and IOCB_DSYNC
  direct-io: remove the offset argument to dio_complete
  direct-io: eliminate the offset argument to ->direct_IO
  xfs: eliminate the pos variable in xfs_file_dio_aio_write
  filemap: remove the pos argument to generic_file_direct_write
  filemap: remove pos variables in generic_file_read_iter
2016-05-17 15:05:23 -07:00
Jan Kara 02fbd13975 dax: Remove complete_unwritten argument
Fault handlers currently take complete_unwritten argument to convert
unwritten extents after PTEs are updated. However no filesystem uses
this anymore as the code is racy. Remove the unused argument.

Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>
2016-05-16 18:11:51 -06:00
Al Viro 3b0a3c1ac1 simple local filesystems: switch to ->iterate_shared()
no changes needed (XFS isn't simple, but it has the same parallelism
in the interesting parts exercised from CXFS).

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02 19:49:32 -04:00
Christoph Hellwig e259221763 fs: simplify the generic_write_sync prototype
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>
2016-05-01 19:58:39 -04:00
Christoph Hellwig dde0c2e798 fs: add IOCB_SYNC and IOCB_DSYNC
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>
2016-05-01 19:58:39 -04:00
Christoph Hellwig c8b8e32d70 direct-io: eliminate the offset argument to ->direct_IO
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>
2016-05-01 19:58:39 -04:00
Christoph Hellwig 13712713ca xfs: eliminate the pos variable in xfs_file_dio_aio_write
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-01 19:58:39 -04:00
Christoph Hellwig 253f4911f2 xfs: better xfs_trans_alloc interface
Merge xfs_trans_reserve and xfs_trans_alloc into a single function call
that returns a transaction with all the required log and block reservations,
and which allows passing transaction flags directly to avoid the cumbersome
_xfs_trans_alloc interface.

While we're at it we also get rid of the transaction type argument that has
been superflous since we stopped supporting the non-CIL logging mode.  The
guts of it will be removed in another patch.

[dchinner: fixed transaction leak in error path in xfs_setattr_nonsize]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-04-06 09:19:55 +10:00
Kirill A. Shutemov 09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
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>
2016-04-04 10:41:08 -07:00
Dave Chinner a2bbcb60ff Merge branch 'xfs-gut-icdinode-4.6' into for-next 2016-03-07 09:30:32 +11:00
Dave Chinner c19b3b05ae xfs: mode di_mode to vfs inode
Move the di_mode value from the xfs_icdinode to the VFS inode, reducing
the xfs_icdinode byte another 2 bytes and collapsing another 2 byte hole
in the structure.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-09 16:54:58 +11:00
Eric Sandeen 8aa7d37ebf xfs: Factor xfs_seek_hole_data into helper
Factor xfs_seek_hole_data into an unlocked helper which takes
an xfs inode rather than a file for internal use.

Also allow specification of "end" - the vfs lseek interface is
defined such that any offset past eof/i_size shall return -ENXIO,
but we will use this for quota code which does not maintain i_size,
and we want to be able to SEEK_DATA past i_size as well.  So the
lseek path can send in i_size, and the quota code can determine
its own ending offset.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-08 11:25:16 +11:00
Linus Torvalds cc673757e2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull final vfs updates from Al Viro:

 - The ->i_mutex wrappers (with small prereq in lustre)

 - a fix for too early freeing of symlink bodies on shmem (they need to
   be RCU-delayed) (-stable fodder)

 - followup to dedupe stuff merged this cycle

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  vfs: abort dedupe loop if fatal signals are pending
  make sure that freeing shmem fast symlinks is RCU-delayed
  wrappers for ->i_mutex access
  lustre: remove unused declaration
2016-01-23 12:24:56 -08:00
Ross Zwisler 5eb88dca9c xfs: call dax_pfn_mkwrite() for DAX fsync/msync
To properly support the new DAX fsync/msync infrastructure filesystems
need to call dax_pfn_mkwrite() so that DAX can track when user pages are
dirtied.

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jan Kara <jack@suse.com>
Cc: Jeff Layton <jlayton@poochiereds.net>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-22 17:02:18 -08:00
Al Viro 5955102c99 wrappers for ->i_mutex access
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>
2016-01-22 18:04:28 -05:00
Dave Chinner a6d7636e8d xfs: fix recursive splice read locking with DAX
Doing a splice read (generic/249) generates a lockdep splat because
we recursively lock the inode iolock in this path:

SyS_sendfile64
do_sendfile
do_splice_direct
splice_direct_to_actor
do_splice_to
xfs_file_splice_read			<<<<<< lock here
default_file_splice_read
vfs_readv
do_readv_writev
do_iter_readv_writev
xfs_file_read_iter			<<<<<< then here

The issue here is that for DAX inodes we need to avoid the page
cache path and hence simply push it into the normal read path.
Unfortunately, we can't tell down at xfs_file_read_iter() whether we
are being called from the splice path and hence we cannot avoid the
locking at this layer. Hence we simply have to drop the inode
locking at the higher splice layer for DAX.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-01-04 16:28:25 +11:00
Linus Torvalds 5d50ac70fe xfs: updates for 4.4-rc1
This update contains:
 o per-mount operational statistics in sysfs
 o fixes for concurrent aio append write submission
 o various logging fixes
 o detection of zeroed logs and invalid log sequence numbers on v5 filesystems
 o memory allocation failure message improvements
 o a bunch of xattr/ACL fixes
 o fdatasync optimisation
 o miscellaneous other fixes and cleanups
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Merge tag 'xfs-for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull xfs updates from Dave Chinner:
 "There is nothing really major here - the only significant addition is
  the per-mount operation statistics infrastructure.  Otherwises there's
  various ACL, xattr, DAX, AIO and logging fixes, and a smattering of
  small cleanups and fixes elsewhere.

  Summary:

   - per-mount operational statistics in sysfs
   - fixes for concurrent aio append write submission
   - various logging fixes
   - detection of zeroed logs and invalid log sequence numbers on v5 filesystems
   - memory allocation failure message improvements
   - a bunch of xattr/ACL fixes
   - fdatasync optimisation
   - miscellaneous other fixes and cleanups"

* tag 'xfs-for-linus-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (39 commits)
  xfs: give all workqueues rescuer threads
  xfs: fix log recovery op header validation assert
  xfs: Fix error path in xfs_get_acl
  xfs: optimise away log forces on timestamp updates for fdatasync
  xfs: don't leak uuid table on rmmod
  xfs: invalidate cached acl if set via ioctl
  xfs: Plug memory leak in xfs_attrmulti_attr_set
  xfs: Validate the length of on-disk ACLs
  xfs: invalidate cached acl if set directly via xattr
  xfs: xfs_filemap_pmd_fault treats read faults as write faults
  xfs: add ->pfn_mkwrite support for DAX
  xfs: DAX does not use IO completion callbacks
  xfs: Don't use unwritten extents for DAX
  xfs: introduce BMAPI_ZERO for allocating zeroed extents
  xfs: fix inode size update overflow in xfs_map_direct()
  xfs: clear PF_NOFREEZE for xfsaild kthread
  xfs: fix an error code in xfs_fs_fill_super()
  xfs: stats are no longer dependent on CONFIG_PROC_FS
  xfs: simplify /proc teardown & error handling
  xfs: per-filesystem stats counter implementation
  ...
2015-11-11 20:18:48 -08:00
Ross Zwisler 5c50002963 vfs: remove unused wrapper block_page_mkwrite()
The function currently called "__block_page_mkwrite()" used to be called
"block_page_mkwrite()" until a wrapper for this function was added by:

commit 24da4fab5a ("vfs: Create __block_page_mkwrite() helper passing
	error values back")

This wrapper, the current "block_page_mkwrite()", is currently unused.
__block_page_mkwrite() is used directly by ext4, nilfs2 and xfs.

Remove the unused wrapper, rename __block_page_mkwrite() back to
block_page_mkwrite() and update the comment above block_page_mkwrite().

Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.com>
Cc: Jan Kara <jack@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-11-11 02:19:33 -05:00
Dave Chinner 264e89ad34 Merge branch 'xfs-dax-updates' into for-next 2015-11-03 13:28:41 +11:00
Dave Chinner 2da5c4b05a Merge branch 'xfs-misc-fixes-for-4.4-2' into for-next 2015-11-03 13:27:58 +11:00
Dave Chinner fc0561cefc xfs: optimise away log forces on timestamp updates for fdatasync
xfs: timestamp updates cause excessive fdatasync log traffic

Sage Weil reported that a ceph test workload was writing to the
log on every fdatasync during an overwrite workload. Event tracing
showed that the only metadata modification being made was the
timestamp updates during the write(2) syscall, but fdatasync(2)
is supposed to ignore them. The key observation was that the
transactions in the log all looked like this:

INODE: #regs: 4   ino: 0x8b  flags: 0x45   dsize: 32

And contained a flags field of 0x45 or 0x85, and had data and
attribute forks following the inode core. This means that the
timestamp updates were triggering dirty relogging of previously
logged parts of the inode that hadn't yet been flushed back to
disk.

There are two parts to this problem. The first is that XFS relogs
dirty regions in subsequent transactions, so it carries around the
fields that have been dirtied since the last time the inode was
written back to disk, not since the last time the inode was forced
into the log.

The second part is that on v5 filesystems, the inode change count
update during inode dirtying also sets the XFS_ILOG_CORE flag, so
on v5 filesystems this makes a timestamp update dirty the entire
inode.

As a result when fdatasync is run, it looks at the dirty fields in
the inode, and sees more than just the timestamp flag, even though
the only metadata change since the last fdatasync was just the
timestamps. Hence we force the log on every subsequent fdatasync
even though it is not needed.

To fix this, add a new field to the inode log item that tracks
changes since the last time fsync/fdatasync forced the log to flush
the changes to the journal. This flag is updated when we dirty the
inode, but we do it before updating the change count so it does not
carry the "core dirty" flag from timestamp updates. The fields are
zeroed when the inode is marked clean (due to writeback/freeing) or
when an fsync/datasync forces the log. Hence if we only dirty the
timestamps on the inode between fsync/fdatasync calls, the fdatasync
will not trigger another log force.

Over 100 runs of the test program:

Ext4 baseline:
	runtime: 1.63s +/- 0.24s
	avg lat: 1.59ms +/- 0.24ms
	iops: ~2000

XFS, vanilla kernel:
        runtime: 2.45s +/- 0.18s
	avg lat: 2.39ms +/- 0.18ms
	log forces: ~400/s
	iops: ~1000

XFS, patched kernel:
        runtime: 1.49s +/- 0.26s
	avg lat: 1.46ms +/- 0.25ms
	log forces: ~30/s
	iops: ~1500

Reported-by: Sage Weil <sage@redhat.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-11-03 13:14:59 +11:00
Dave Chinner 13ad4fe3e0 xfs: xfs_filemap_pmd_fault treats read faults as write faults
The code initially committed didn't have the same checks for write
faults as the dax_pmd_fault code and hence treats all faults as
write faults. We can get read faults through this path because they
is no pmd_mkwrite path for write faults similar to the normal page
fault path. Hence we need to ensure that we only do c/mtime updates
on write faults, and freeze protection is unnecessary for read
faults.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-11-03 12:37:02 +11:00
Dave Chinner 3af4928585 xfs: add ->pfn_mkwrite support for DAX
->pfn_mkwrite support is needed so that when a page with allocated
backing store takes a write fault we can check that the fault has
not raced with a truncate and is pointing to a region beyond the
current end of file.

This also allows us to update the timestamp on the inode, too, which
fixes a generic/080 failure.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-11-03 12:37:02 +11:00
Dave Chinner 01a155e6cf xfs: DAX does not use IO completion callbacks
For DAX, we are now doing block zeroing during allocation. This
means we no longer need a special DAX fault IO completion callback
to do unwritten extent conversion. Because mmap never extends the
file size (it SEGVs the process) we don't need a callback to update
the file size, either. Hence we can remove the completion callbacks
from the __dax_fault and __dax_mkwrite calls.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-11-03 12:37:02 +11:00
Dave Chinner 3e12dbbdbd xfs: fix inode size update overflow in xfs_map_direct()
Both direct IO and DAX pass an offset and count into get_blocks that
will overflow a s64 variable when an IO goes into the last supported
block in a file (i.e. at offset 2^63 - 1FSB bytes). This can be seen
from the tracing:

xfs_get_blocks_alloc: [...] offset 0x7ffffffffffff000 count 4096
xfs_gbmap_direct:     [...] offset 0x7ffffffffffff000 count 4096
xfs_gbmap_direct_none:[...] offset 0x7ffffffffffff000 count 4096

0x7ffffffffffff000 + 4096 = 0x8000000000000000, and hence that
overflows the s64 offset and we fail to detect the need for a
filesize update and an ioend is not allocated.

This is *mostly* avoided for direct IO because such extending IOs
occur with full block allocation, and so the "IS_UNWRITTEN()" check
still evaluates as true and we get an ioend that way. However, doing
single sector extending IOs to this last block will expose the fact
that file size updates will not occur after the first allocating
direct IO as the overflow will then be exposed.

There is one further complexity: the DAX page fault path also
exposes the same issue in block allocation. However, page faults
cannot extend the file size, so in this case we want to allocate the
block but do not want to allocate an ioend to enable file size
update at IO completion. Hence we now need to distinguish between
the direct IO patch allocation and dax fault path allocation to
avoid leaking ioend structures.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-11-03 12:27:22 +11:00
Dave Chinner 8a56d7c305 Merge branch 'xfs-io-fixes' into for-next 2015-10-12 18:38:11 +11:00
Bill O'Donnell ff6d6af235 xfs: per-filesystem stats counter implementation
This patch modifies the stats counting macros and the callers
to those macros to properly increment, decrement, and add-to
the xfs stats counts. The counts for global and per-fs stats
are correctly advanced, and cleared by writing a "1" to the
corresponding clear file.

global counts: /sys/fs/xfs/stats/stats
per-fs counts: /sys/fs/xfs/sda*/stats/stats

global clear:  /sys/fs/xfs/stats/stats_clear
per-fs clear:  /sys/fs/xfs/sda*/stats/stats_clear

[dchinner: cleaned up macro variables, removed CONFIG_FS_PROC around
 stats structures and macros. ]

Signed-off-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-10-12 18:21:22 +11:00
Brian Foster 0a50f162af xfs: add an xfs_zero_eof() tracepoint
Add a tracepoint in xfs_zero_eof() to facilitate tracking and debugging
EOF zeroing events. This has proven useful in the context of other
direct I/O tracepoints to ensure EOF zeroing occurs within appropriate
file ranges.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-10-12 16:02:08 +11:00
Brian Foster 3136e8bb30 xfs: always drain dio before extending aio write submission
XFS supports and typically allows concurrent asynchronous direct I/O
submission to a single file. One exception to the rule is that file
extending dio writes that start beyond the current EOF (e.g.,
potentially create a hole at EOF) require exclusive I/O access to the
file. This is because such writes must zero any pre-existing blocks
beyond EOF that are exposed by virtue of now residing within EOF as a
result of the write about to be submitted.

Before EOF zeroing can occur, the current file i_size must be stabilized
to avoid data corruption. In this scenario, XFS upgrades the iolock to
exclude any further I/O submission, waits on in-flight I/O to complete
to ensure i_size is up to date (i_size is updated on dio write
completion) and restarts the various checks against the state of the
file. The problem is that this protection sequence is triggered only
when the iolock is currently held shared. While this is true for async
dio in most cases, the caller may upgrade the lock in advance based on
arbitrary circumstances with respect to EOF zeroing. For example, the
iolock is always acquired exclusively if the start offset is not block
aligned. This means that even though the iolock is already held
exclusive for such I/Os, pending I/O is not drained and thus EOF zeroing
can occur based on an unstable i_size.

This problem has been reproduced as guest data corruption in virtual
machines with file-backed qcow2 virtual disks hosted on an XFS
filesystem. The virtual disks must be configured with aio=native mode
and the must not be truncated out to the maximum file size (as some virt
managers will do).

Update xfs_file_aio_write_checks() to unconditionally drain in-flight
dio before EOF zeroing can occur. Rather than trigger the wait based on
iolock state, use a new flag and upgrade the iolock when necessary. Note
that this results in a full restart of the inode checks even when the
iolock was already held exclusive when technically it is only required
to recheck i_size. This should be a rare enough occurrence that it is
preferable to keep the code simple rather than create an alternate
restart jump target.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-10-12 16:02:05 +11:00
Matthew Wilcox acd76e74d8 xfs: huge page fault support
Use DAX to provide support for huge pages.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-08 15:35:28 -07:00
Dave Chinner aa493382cb Merge branch 'xfs-misc-fixes-for-4.3-2' into for-next 2015-08-20 09:28:45 +10:00
Brian Foster 3d751af2cb xfs: flush entire file on dio read/write to cached file
Filesystems are responsible to manage file coherency between the page
cache and direct I/O. The generic dio code flushes dirty pages over the
range of a dio to ensure that the dio read or a future buffered read
returns the correct data. XFS has generally followed this pattern,
though traditionally has flushed and invalidated the range from the
start of the I/O all the way to the end of the file. This changed after
the following commit:

	7d4ea3ce xfs: use ranged writeback and invalidation for direct IO

... as the full file flush was no longer necessary to deal with the
strange post-eof delalloc issues that were since fixed. Unfortunately,
we have since received complaints about performance degradation due to
the increased exclusive iolock cycles (which locks out parallel dio
submission) that occur when a file has cached pages. This does not occur
on filesystems that use the generic code as it also does not incorporate
locking.

The exclusive iolock is acquired any time the inode mapping has cached
pages, regardless of whether they reside in the range of the I/O or not.
If not, the flush/inval calls do no work and the lock was cycled for no
reason.

Under consideration of the cost of the exclusive iolock, update the dio
read and write handlers to flush and invalidate the entire mapping when
cached pages exist. In most cases, this increases the cost of the
initial flush sequence but eliminates the need for further lock cycles
and flushes so long as the workload does not actively mix direct and
buffered I/O. This also more closely matches historical behavior and
performance characteristics that users have come to expect.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-08-19 10:35:04 +10:00
Dave Chinner b2442c5a7f xfs: call dax_fault on read page faults for DAX
When modifying the patch series to handle the XFS MMAP_LOCK nesting
of page faults, I botched the conversion of the read page fault
path, and so it is only every calling through the page cache. Re-add
the necessary __dax_fault() call for such files.

Because the get_blocks callback on read faults may not set up the
mapping buffer correctly to allow unwritten extent completion to be
run, we need to allow callers of __dax_fault() to pass a null
complete_unwritten() callback. The DAX code always zeros the
unwritten page when it is read faulted so there are no stale data
exposure issues with not doing the conversion. The only downside
will be the potential for increased CPU overhead on repeated read
faults of the same page. If this proves to be a problem, then the
filesystem needs to fix it's get_block callback and provide a
convert_unwritten() callback to the read fault path.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Matthew Wilcox <willy@linux.intel.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-07-29 11:48:00 +10:00
Linus Torvalds 1dc51b8288 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more vfs updates from Al Viro:
 "Assorted VFS fixes and related cleanups (IMO the most interesting in
  that part are f_path-related things and Eric's descriptor-related
  stuff).  UFS regression fixes (it got broken last cycle).  9P fixes.
  fs-cache series, DAX patches, Jan's file_remove_suid() work"

[ I'd say this is much more than "fixes and related cleanups".  The
  file_table locking rule change by Eric Dumazet is a rather big and
  fundamental update even if the patch isn't huge.   - Linus ]

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (49 commits)
  9p: cope with bogus responses from server in p9_client_{read,write}
  p9_client_write(): avoid double p9_free_req()
  9p: forgetting to cancel request on interrupted zero-copy RPC
  dax: bdev_direct_access() may sleep
  block: Add support for DAX reads/writes to block devices
  dax: Use copy_from_iter_nocache
  dax: Add block size note to documentation
  fs/file.c: __fget() and dup2() atomicity rules
  fs/file.c: don't acquire files->file_lock in fd_install()
  fs:super:get_anon_bdev: fix race condition could cause dev exceed its upper limitation
  vfs: avoid creation of inode number 0 in get_next_ino
  namei: make set_root_rcu() return void
  make simple_positive() public
  ufs: use dir_pages instead of ufs_dir_pages()
  pagemap.h: move dir_pages() over there
  remove the pointless include of lglock.h
  fs: cleanup slight list_entry abuse
  xfs: Correctly lock inode when removing suid and file capabilities
  fs: Call security_ops->inode_killpriv on truncate
  fs: Provide function telling whether file_remove_privs() will do anything
  ...
2015-07-04 19:36:06 -07:00
Linus Torvalds 68b4449d79 xfs: update for 4.2-rc1
This update contains:
 
 o A new sparse on-disk inode record format to allow small extents to
   be used for inode allocation when free space is fragmented.
 o DAX support. This includes minor changes to the DAX core code to
   fix problems with lock ordering and bufferhead mapping abuse.
 o transaction commit interface cleanup
 o removal of various unnecessary XFS specific type definitions
 o cleanup and optimisation of freelist preparation before allocation
 o various minor cleanups
 o bug fixes for
 	- transaction reservation leaks
 	- incorrect inode logging in unwritten extent conversion
 	- mmap lock vs freeze ordering
 	- remote symlink mishandling
 	- attribute fork removal issues.
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Merge tag 'xfs-for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pul xfs updates from Dave Chinner:
 "There's a couple of small API changes to the core DAX code which
  required small changes to the ext2 and ext4 code bases, but otherwise
  everything is within the XFS codebase.

  This update contains:

   - A new sparse on-disk inode record format to allow small extents to
     be used for inode allocation when free space is fragmented.

   - DAX support.  This includes minor changes to the DAX core code to
     fix problems with lock ordering and bufferhead mapping abuse.

   - transaction commit interface cleanup

   - removal of various unnecessary XFS specific type definitions

   - cleanup and optimisation of freelist preparation before allocation

   - various minor cleanups

   - bug fixes for
	- transaction reservation leaks
	- incorrect inode logging in unwritten extent conversion
	- mmap lock vs freeze ordering
	- remote symlink mishandling
	- attribute fork removal issues"

* tag 'xfs-for-linus-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (49 commits)
  xfs: don't truncate attribute extents if no extents exist
  xfs: clean up XFS_MIN_FREELIST macros
  xfs: sanitise error handling in xfs_alloc_fix_freelist
  xfs: factor out free space extent length check
  xfs: xfs_alloc_fix_freelist() can use incore perag structures
  xfs: remove xfs_caddr_t
  xfs: use void pointers in log validation helpers
  xfs: return a void pointer from xfs_buf_offset
  xfs: remove inst_t
  xfs: remove __psint_t and __psunsigned_t
  xfs: fix remote symlinks on V5/CRC filesystems
  xfs: fix xfs_log_done interface
  xfs: saner xfs_trans_commit interface
  xfs: remove the flags argument to xfs_trans_cancel
  xfs: pass a boolean flag to xfs_trans_free_items
  xfs: switch remaining xfs_trans_dup users to xfs_trans_roll
  xfs: check min blks for random debug mode sparse allocations
  xfs: fix sparse inodes 32-bit compile failure
  xfs: add initial DAX support
  xfs: add DAX IO path support
  ...
2015-06-30 20:16:08 -07:00
Linus Torvalds e4bc13adfd Merge branch 'for-4.2/writeback' of git://git.kernel.dk/linux-block
Pull cgroup writeback support from Jens Axboe:
 "This is the big pull request for adding cgroup writeback support.

  This code has been in development for a long time, and it has been
  simmering in for-next for a good chunk of this cycle too.  This is one
  of those problems that has been talked about for at least half a
  decade, finally there's a solution and code to go with it.

  Also see last weeks writeup on LWN:

        http://lwn.net/Articles/648292/"

* 'for-4.2/writeback' of git://git.kernel.dk/linux-block: (85 commits)
  writeback, blkio: add documentation for cgroup writeback support
  vfs, writeback: replace FS_CGROUP_WRITEBACK with SB_I_CGROUPWB
  writeback: do foreign inode detection iff cgroup writeback is enabled
  v9fs: fix error handling in v9fs_session_init()
  bdi: fix wrong error return value in cgwb_create()
  buffer: remove unusued 'ret' variable
  writeback: disassociate inodes from dying bdi_writebacks
  writeback: implement foreign cgroup inode bdi_writeback switching
  writeback: add lockdep annotation to inode_to_wb()
  writeback: use unlocked_inode_to_wb transaction in inode_congested()
  writeback: implement unlocked_inode_to_wb transaction and use it for stat updates
  writeback: implement [locked_]inode_to_wb_and_lock_list()
  writeback: implement foreign cgroup inode detection
  writeback: make writeback_control track the inode being written back
  writeback: relocate wb[_try]_get(), wb_put(), inode_{attach|detach}_wb()
  mm: vmscan: disable memcg direct reclaim stalling if cgroup writeback support is in use
  writeback: implement memcg writeback domain based throttling
  writeback: reset wb_domain->dirty_limit[_tstmp] when memcg domain size changes
  writeback: implement memcg wb_domain
  writeback: update wb_over_bg_thresh() to use wb_domain aware operations
  ...
2015-06-25 16:00:17 -07:00
Jan Kara a6de82cab1 xfs: Correctly lock inode when removing suid and file capabilities
Currently XFS calls file_remove_privs() without holding i_mutex. This is
wrong because that function can end up messing with file permissions and
file capabilities stored in xattrs for which we need i_mutex held.

Fix the problem by grabbing iolock exclusively when we will need to
change anything in permissions / xattrs.

Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:01:10 -04:00
Jan Kara 5fa8e0a1c6 fs: Rename file_remove_suid() to file_remove_privs()
file_remove_suid() is a misnomer since it removes also file capabilities
stored in xattrs and sets S_NOSEC flag. Also should_remove_suid() tells
something else than whether file_remove_suid() call is necessary which
leads to bugs.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-06-23 18:01:08 -04:00
Dave Chinner 4ea7976616 Merge branch 'xfs-commit-cleanup' into for-next
Conflicts:
	fs/xfs/xfs_attr_inactive.c
2015-06-04 13:55:48 +10:00
Christoph Hellwig 70393313dd xfs: saner xfs_trans_commit interface
The flags argument to xfs_trans_commit is not useful for most callers, as
a commit of a transaction without a permanent log reservation must pass
0 here, and all callers for a transaction with a permanent log reservation
except for xfs_trans_roll must pass XFS_TRANS_RELEASE_LOG_RES.  So remove
the flags argument from the public xfs_trans_commit interfaces, and
introduce low-level __xfs_trans_commit variant just for xfs_trans_roll
that regrants a log reservation instead of releasing it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-04 13:48:08 +10:00
Christoph Hellwig 4906e21545 xfs: remove the flags argument to xfs_trans_cancel
xfs_trans_cancel takes two flags arguments: XFS_TRANS_RELEASE_LOG_RES and
XFS_TRANS_ABORT.  Both of them are a direct product of the transaction
state, and can be deducted:

 - any dirty transaction needs XFS_TRANS_ABORT to be properly canceled,
   and XFS_TRANS_ABORT is a noop for a transaction that is not dirty.
 - any transaction with a permanent log reservation needs
   XFS_TRANS_RELEASE_LOG_RES to be properly canceled, and passing
   XFS_TRANS_RELEASE_LOG_RES for a transaction without a permanent
   log reservation is invalid.

So just remove the flags argument and do the right thing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-04 13:47:56 +10:00
Dave Chinner 66e8ac7bfa Merge branch 'xfs-dax-support' into for-next 2015-06-04 13:01:49 +10:00
Dave Chinner 4f69f578a8 xfs: add DAX block zeroing support
Add initial support for DAX block zeroing operations to XFS. DAX
cannot use buffered IO through the page cache for zeroing, nor do we
need to issue IO for uncached block zeroing. In both cases, we can
simply call out to the dax block zeroing function.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-04 09:19:08 +10:00
Dave Chinner 6b698edeee xfs: add DAX file operations support
Add the initial support for DAX file operations to XFS. This
includes the necessary block allocation and mmap page fault hooks
for DAX to function.

Note that there are changes to the splice interfaces to ensure that
for DAX splice avoids direct page cache manipulations and instead
takes the DAX IO paths for read/write operations.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-04 09:18:53 +10:00
Dave Chinner ec56b1f1fd xfs: mmap lock needs to be inside freeze protection
Lock ordering for the new mmap lock needs to be:

mmap_sem
  sb_start_pagefault
    i_mmap_lock
      page lock
        <fault processsing>

Right now xfs_vm_page_mkwrite gets this the wrong way around,
While technically it cannot deadlock due to the current freeze
ordering, it's still a landmine that might explode if we change
anything in future. Hence we need to nest the locks correctly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-04 09:18:18 +10:00
Tejun Heo 66114cad64 writeback: separate out include/linux/backing-dev-defs.h
With the planned cgroup writeback support, backing-dev related
declarations will be more widely used across block and cgroup;
unfortunately, including backing-dev.h from include/linux/blkdev.h
makes cyclic include dependency quite likely.

This patch separates out backing-dev-defs.h which only has the
essential definitions and updates blkdev.h to include it.  c files
which need access to more backing-dev details now include
backing-dev.h directly.  This takes backing-dev.h off the common
include dependency chain making it a lot easier to use it across block
and cgroup.

v2: fs/fat build failure fixed.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Jens Axboe <axboe@fb.com>
2015-06-02 08:33:34 -06:00
Dave Chinner cddc116228 xfs: xfs_iozero can return positive errno
It was missed when we converted everything in XFs to use negative error
numbers, so fix it now. Bug introduced in 3.17 by commit 2451337 ("xfs: global
error sign conversion"), and should go back to stable kernels.

Thanks to Brian Foster for noticing it.

cc: <stable@vger.kernel.org> # 3.17, 3.18, 3.19, 4.0
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-05-29 07:40:32 +10:00
Linus Torvalds 1aef882f02 xfs: update for 4.1-rc1
This update contains:
 o RENAME_WHITEOUT support
 o conversion of per-cpu superblock accounting to use generic counters
 o new inode mmap lock so that we can lock page faults out of truncate, hole
   punch and other direct extent manipulation functions to avoid racing mmap
   writes from causing data corruption
 o rework of direct IO submission and completion to solve data corruption issue
   when running concurrent extending DIO writes. Also solves problem of running
   IO completion transactions in interrupt context during size extending AIO
   writes.
 o FALLOC_FL_INSERT_RANGE support for inserting holes into a file via direct
   extent manipulation to avoid needing to copy data within the file
 o attribute block header field overflow fix for 64k block size filesystems
 o Lots of changes to log messaging to be more informative and concise when
   errors occur. Also prevent a lot of unnecessary log spamming due to cascading
   failures in error conditions.
 o lots of cleanups and bug fixes
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Merge tag 'xfs-for-linus-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs

Pull xfs update from Dave Chinner:
 "This update contains:

   - RENAME_WHITEOUT support

   - conversion of per-cpu superblock accounting to use generic counters

   - new inode mmap lock so that we can lock page faults out of
     truncate, hole punch and other direct extent manipulation functions
     to avoid racing mmap writes from causing data corruption

   - rework of direct IO submission and completion to solve data
     corruption issue when running concurrent extending DIO writes.
     Also solves problem of running IO completion transactions in
     interrupt context during size extending AIO writes.

   - FALLOC_FL_INSERT_RANGE support for inserting holes into a file via
     direct extent manipulation to avoid needing to copy data within the
     file

   - attribute block header field overflow fix for 64k block size
     filesystems

   - Lots of changes to log messaging to be more informative and concise
     when errors occur.  Also prevent a lot of unnecessary log spamming
     due to cascading failures in error conditions.

   - lots of cleanups and bug fixes

  One thing of note is the direct IO fixes that we merged last week
  after the window opened.  Even though a little late, they fix a user
  reported data corruption and have been pretty well tested.  I figured
  there was not much point waiting another 2 weeks for -rc1 to be
  released just so I could send them to you..."

* tag 'xfs-for-linus-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (49 commits)
  xfs: using generic_file_direct_write() is unnecessary
  xfs: direct IO EOF zeroing needs to drain AIO
  xfs: DIO write completion size updates race
  xfs: DIO writes within EOF don't need an ioend
  xfs: handle DIO overwrite EOF update completion correctly
  xfs: DIO needs an ioend for writes
  xfs: move DIO mapping size calculation
  xfs: factor DIO write mapping from get_blocks
  xfs: unlock i_mutex in xfs_break_layouts
  xfs: kill unnecessary firstused overflow check on attr3 leaf removal
  xfs: use larger in-core attr firstused field and detect overflow
  xfs: pass attr geometry to attr leaf header conversion functions
  xfs: disallow ro->rw remount on norecovery mount
  xfs: xfs_shift_file_space can be static
  xfs: Add support FALLOC_FL_INSERT_RANGE for fallocate
  fs: Add support FALLOC_FL_INSERT_RANGE for fallocate
  xfs: Fix incorrect positive ENOMEM return
  xfs: xfs_mru_cache_insert() should use GFP_NOFS
  xfs: %pF is only for function pointers
  xfs: fix shadow warning in xfs_da3_root_split()
  ...
2015-04-24 07:08:41 -07:00
Dave Chinner 542c311813 Merge branch 'xfs-dio-extend-fix' into for-next
Conflicts:
	fs/xfs/xfs_file.c
2015-04-16 22:13:18 +10:00
Dave Chinner 0cefb29e6a xfs: using generic_file_direct_write() is unnecessary
generic_file_direct_write() does all sorts of things to make DIO
work "sorta ok" with mixed buffered IO workloads. We already do
most of this work in xfs_file_aio_dio_write() because of the locking
requirements, so there's only a couple of things it does for us.

The first thing is that it does a page cache invalidation after the
->direct_IO callout. This can easily be added to the XFS code.

The second thing it does is that if data was written, it updates the
iov_iter structure to reflect the data written, and then does EOF
size updates if necessary. For XFS, these EOF size updates are now
not necessary, as we do them safely and race-free in IO completion
context. That leaves just the iov_iter update, and that's also moved
to the XFS code.

Therefore we don't need to call generic_file_direct_write() and in
doing so remove redundant buffered writeback and page cache
invalidation calls from the DIO submission path. We also remove a
racy EOF size update, and make the DIO submission code in XFS much
easier to follow. Wins all round, really.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-04-16 22:03:27 +10:00
Dave Chinner 40c63fbc55 xfs: direct IO EOF zeroing needs to drain AIO
When we are doing AIO DIO writes, the IOLOCK only provides an IO
submission barrier. When we need to do EOF zeroing, we need to ensure
that no other IO is in progress and all pending in-core EOF updates
have been completed. This requires us to wait for all outstanding
AIO DIO writes to the inode to complete and, if necessary, run their
EOF updates.

Once all the EOF updates are complete, we can then restart
xfs_file_aio_write_checks() while holding the IOLOCK_EXCL, knowing
that EOF is up to date and we have exclusive IO access to the file
so we can run EOF block zeroing if we need to without interference.
This gives EOF zeroing the same exclusivity against other IO as we
provide truncate operations.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-04-16 22:03:17 +10:00
Dave Chinner b9d59846f7 xfs: DIO write completion size updates race
xfs_end_io_direct_write() can race with other IO completions when
updating the in-core inode size. The IO completion processing is not
serialised for direct IO - they are done either under the
IOLOCK_SHARED for non-AIO DIO, and without any IOLOCK held at all
during AIO DIO completion. Hence the non-atomic test-and-set update
of the in-core inode size is racy and can result in the in-core
inode size going backwards if the race if hit just right.

If the inode size goes backwards, this can trigger the EOF zeroing
code to run incorrectly on the next IO, which then will zero data
that has successfully been written to disk by a previous DIO.

To fix this bug, we need to serialise the test/set updates of the
in-core inode size. This first patch introduces locking around the
relevant updates and checks in the DIO path. Because we now have an
ioend in xfs_end_io_direct_write(), we know exactly then we are
doing an IO that requires an in-core EOF update, and we know that
they are not running in interrupt context. As such, we do not need to
use irqsave() spinlock variants to protect against interrupts while
the lock is held.

Hence we can use an existing spinlock in the inode to do this
serialisation and so not need to grow the struct xfs_inode just to
work around this problem.

This patch does not address the test/set EOF update in
generic_file_write_direct() for various reasons - that will be done
as a followup with separate explanation.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-04-16 22:03:07 +10:00
Dave Chinner 6a63ef064b Merge branch 'xfs-misc-fixes-for-4.1-3' into for-next
Conflicts:
	fs/xfs/xfs_iops.c
2015-04-13 11:40:16 +10:00
Christoph Hellwig 21c3ea1881 xfs: unlock i_mutex in xfs_break_layouts
We want to drop all I/O path locks when recalling layouts, and that includes
i_mutex for the write path.  Without this we get stuck processe when recalls
take too long.

[dchinner: fix build with !CONFIG_PNFS]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-04-13 11:38:29 +10:00
Al Viro 2ba48ce513 mirror O_APPEND and O_DIRECT into iocb->ki_flags
... avoiding write_iter/fcntl races.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:30:22 -04:00
Al Viro 3309dd04cb switch generic_write_checks() to iocb and iter
... returning -E... upon error and amount of data left in iter after
(possible) truncation upon success.  Note, that normal case gives
a non-zero (positive) return value, so any tests for != 0 _must_ be
updated.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Conflicts:
	fs/ext4/file.c
2015-04-11 22:30:21 -04:00
Al Viro 99733fa372 xfs_file_aio_write_checks: switch to iocb/iov_iter
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:49 -04:00
Al Viro 0fa6b005af generic_write_checks(): drop isblk argument
all remaining callers are passing 0; some just obscure that fact.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:48 -04:00
Al Viro 5d5d568975 make new_sync_{read,write}() static
All places outside of core VFS that checked ->read and ->write for being NULL or
called the methods directly are gone now, so NULL {read,write} with non-NULL
{read,write}_iter will do the right thing in all cases.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-04-11 22:29:40 -04:00
Al Viro c0fec3a98b Merge branch 'iocb' into for-next 2015-04-11 22:24:41 -04:00
Christoph Hellwig e2e40f2c1e fs: move struct kiocb to fs.h
struct kiocb now is a generic I/O container, so move it to fs.h.
Also do a #include diet for aio.h while we're at it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-03-25 20:28:11 -04:00
Dave Chinner a448f8f1b7 Merge branch 'fallocate-insert-range' into for-next 2015-03-25 15:12:53 +11:00
Namjae Jeon a904b1ca57 xfs: Add support FALLOC_FL_INSERT_RANGE for fallocate
This patch implements fallocate's FALLOC_FL_INSERT_RANGE for XFS.

1) Make sure that both offset and len are block size aligned.
2) Update the i_size of inode by len bytes.
3) Compute the file's logical block number against offset. If the computed
   block number is not the starting block of the extent, split the extent
   such that the block number is the starting block of the extent.
4) Shift all the extents which are lying bewteen [offset, last allocated extent]
   towards right by len bytes. This step will make a hole of len bytes
   at offset.

Signed-off-by: Namjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: Ashish Sangwan <a.sangwan@samsung.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-03-25 15:08:56 +11:00
Dave Chinner 88e8fda99a Merge branch 'xfs-mmap-lock' into for-next 2015-02-24 10:27:47 +11:00
Dave Chinner 5885ebda87 xfs: ensure truncate forces zeroed blocks to disk
A new fsync vs power fail test in xfstests indicated that XFS can
have unreliable data consistency when doing extending truncates that
require block zeroing. The blocks beyond EOF get zeroed in memory,
but we never force those changes to disk before we run the
transaction that extends the file size and exposes those blocks to
userspace. This can result in the blocks not being correctly zeroed
after a crash.

Because in-memory behaviour is correct, tools like fsx don't pick up
any coherency problems - it's not until the filesystem is shutdown
or the system crashes after writing the truncate transaction to the
journal but before the zeroed data in the page cache is flushed that
the issue is exposed.

Fix this by also flushing the dirty data in memory region between
the old size and new size when we've found blocks that need zeroing
in the truncate process.

Reported-by: Liu Bo <bo.li.liu@oracle.com>
cc: <stable@vger.kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-02-23 22:37:08 +11:00
Dave Chinner e8e9ad42c1 xfs: take i_mmap_lock on extent manipulation operations
Now we have the i_mmap_lock being held across the page fault IO
path, we now add extent manipulation operation exclusion by adding
the lock to the paths that directly modify extent maps. This
includes truncate, hole punching and other fallocate based
operations. The operations will now take both the i_iolock and the
i_mmaplock in exclusive mode, thereby ensuring that all IO and page
faults block without holding any page locks while the extent
manipulation is in progress.

This gives us the lock order during truncate of i_iolock ->
i_mmaplock -> page_lock -> i_lock, hence providing the same
lock order as the iolock provides the normal IO path without
involving the mmap_sem.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-02-23 21:45:32 +11:00