The near mode bnobt scan searches left and right in the bnobt
looking for the closest free extent to the allocation hint that
satisfies minlen. Once such an extent is found, the left/right
search terminates, we search one more time in the opposite direction
and finish the allocation with the best overall extent.

The left/right and find best searches are currently controlled via a
combination of cursor state and local variables. Clean up this code
and prepare for further improvements to the near mode fallback
algorithm by reusing the allocation cursor best extent tracking
mechanism. Update the tracking logic to deactivate bnobt cursors
when out of allocation range and replace open-coded extent checks to
calls to the common helper. In doing so, rename some misnamed local
variables in the top-level near mode allocation function.
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>

The cntbt lastblock scan checks the size, alignment, locality, etc.
of each free extent in the block and compares it with the current
best candidate. This logic will be reused by the upcoming optimized
cntbt algorithm, so refactor it into a separate helper. Note that
acur->diff is now initialized to -1 (unsigned) instead of 0 to
support the more granular comparison logic in the new helper.
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>

If the size lookup lands in the last block of the by-size btree, the
near mode algorithm scans the entire block for the extent with best
available locality. In preparation for similar best available
extent tracking across both btrees, extend the allocation cursor
with best extent data and lift the associated state from the cntbt
last block scan code. No functional changes.
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>

Extend the allocation cursor to track extent busy state for an
allocation attempt. No functional changes.
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>

Introduce a new allocation cursor data structure to encapsulate the
various states and structures used to perform an extent allocation.
This structure will eventually be used to track overall allocation
state across different search algorithms on both free space btrees.

To start, include the three btree cursors (one for the cntbt and two
for the bnobt left/right search) used by the near mode allocation
algorithm and refactor the cursor setup and teardown code into
helpers. This slightly changes cursor memory allocation patterns,
but otherwise makes no functional changes to the allocation
algorithm.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: fix sparse complaints]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

The upcoming allocation algorithm update searches multiple
allocation btree cursors concurrently. As such, it requires an
active state to track when a particular cursor should continue
searching. While active state will be modified based on higher level
logic, we can define base functionality based on the result of
allocation btree lookups.

Define an active flag in the private area of the btree cursor.
Update it based on the result of lookups in the existing allocation
btree helpers. Finally, provide a new helper to query the current
state.
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>

There is no point in applying extent size hints for always COW inodes,
as we would just have to COW any extra allocation beyond the data
actually written.
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>

In commit d03a2f1b ("xfs: include WARN, REPAIR build options in
XFS_BUILD_OPTIONS"), Eric pointed out that the XFS_BUILD_OPTIONS string,
shown at module init time and in modinfo output, does not currently
include all available build options. So, he added in CONFIG_XFS_WARN and
CONFIG_XFS_REPAIR. However, this is not enough, add in CONFIG_XFS_QUOTA
and CONFIG_XFS_ASSERT_FATAL.
Signed-off-by: yu kuai <yukuai3@huawei.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

The srcmap is used to identify where the read is to be performed from.
It is passed to ->iomap_begin, which can fill it in if we need to read
data for partially written blocks from a different location than the
write target.  The srcmap is only supported for buffered writes so far.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
[hch: merged two patches, removed the IOMAP_F_COW flag, use iomap as
      srcmap if not set, adjust length down to srcmap end as well]
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>
Acked-by: Goldwyn Rodrigues <rgoldwyn@suse.com>

Instead of keeping a separate unnamed state for uninitialized iomaps,
renumber IOMAP_HOLE to zero so that an uninitialized iomap is treated
as a hole.
Suggested-by: Darrick J. Wong <darrick.wong@oracle.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>

Use the existing iomap write_begin code to read the pages unshared
by iomap_file_unshare.  That avoids the extra ->readpage call and
extent tree lookup currently done by read_mapping_page.
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>

That keeps the function a little easier to understand, and easier to
modify for pending enhancements.
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>

xfs_file_dirty is used to unshare reflink blocks.  Rename the function
to xfs_file_unshare to better document that purpose, and skip iomaps
that are not shared and don't need zeroing.  This will allow to simplify
the caller.
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>

All callers pass AOP_FLAG_NOFS, so lift that flag to iomap_write_begin
to allow reusing the flags arguments for an internal flags namespace
soon.  Also remove the local index variable that is only used once.
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>

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

The documentation for IOMAP_F_* is a bit disorganized, and doesn't
mention the fact that most flags are set by the file system and consumed
by the iomap core, while IOMAP_F_SIZE_CHANGED is set by the core and
consumed by the file system.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

If we encounter an IO error during writeback, log the inode, offset, and
sector number of the failure, instead of forcing the user to do some
sort of reverse mapping to figure out which file is affected.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

No need to pass the full bio_vec.
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>

Move the initialization of ia and ib to the declaration line and remove
a superflous else.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Now that all the writepage code is in the iomap code there is no
need to keep this structure public.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

And inline mapping should never mark the page dirty and thus never end up
in writepages.  Add a check for that condition and warn if it happens.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Take the xfs writeback code and move it to fs/iomap.  A new structure
with three methods is added as the abstraction from the generic writeback
code to the file system.  These methods are used to map blocks, submit an
ioend, and cancel a page that encountered an error before it was added to
an ioend.
Signed-off-by: Christoph Hellwig <hch@lst.de>
[darrick: rename ->submit_ioend to ->prepare_ioend to clarify what it
does]
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Lift the xfs code for tracing address space operations to the iomap
layer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

File systems like gfs2 don't support delayed allocations or unwritten
extents and thus allocate normal mapped blocks to fill holes.  To
cover the case of such file systems allocating new blocks to fill holes
also zero out mapped blocks with the new flag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

In preparation for moving the writeback code to iomap.c, replace the
XFS-specific COW fork concept with the iomap IOMAP_F_SHARED flag.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

In preparation for moving the ioend structure to common code we need
to get rid of the xfs-specific xfs_trans type.  Just make it a file
system private void pointer instead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Introduce two nicely abstracted helper, which can be moved to the iomap
code later.  Also use list_first_entry_or_null to simplify the code a
bit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

In preparation for moving the XFS writeback code to fs/iomap.c, switch
it to use struct iomap instead of the XFS-specific struct xfs_bmbt_irec.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Don't set IOMAP_F_NEW if we COW over an existing allocated range, as
these aren't strictly new allocations.  This is required to be able to
use IOMAP_F_NEW to zero newly allocated blocks, which is required for
the iomap code to fully support file systems that don't do delayed
allocations or use unwritten extents.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Currently we don't overwrite the flags field in the iomap in
xfs_bmbt_to_iomap.  This works fine with 0-initialized iomaps on stack,
but is harmful once we want to be able to reuse an iomap in the
writeback code.  Replace the shared parameter with a set of initial
flags an thus ensures the flags field is always reinitialized.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

When doing a direct IO that spans the current EOF, and there are
written blocks beyond EOF that extend beyond the current write, the
only metadata update that needs to be done is a file size extension.

However, we don't mark such iomaps as IOMAP_F_DIRTY to indicate that
there is IO completion metadata updates required, and hence we may
fail to correctly sync file size extensions made in IO completion
when O_DSYNC writes are being used and the hardware supports FUA.

Hence when setting IOMAP_F_DIRTY, we need to also take into account
whether the iomap spans the current EOF. If it does, then we need to
mark it dirty so that IO completion will call generic_write_sync()
to flush the inode size update to stable storage correctly.

Fixes: 3460cac1 ("iomap: Use FUA for pure data O_DSYNC DIO writes")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: removed the ext4 part; they'll handle it separately]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Use iomap_dio_rw() to wait for unaligned direct IO instead of opencoding
the wait.
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>

Filesystems do not support doing IO as asynchronous in some cases. For
example in case of unaligned writes or in case file size needs to be
extended (e.g. for ext4). Instead of forcing filesystem to wait for AIO
in such cases, add argument to iomap_dio_rw() which makes the function
wait for IO completion. This also results in executing
iomap_dio_complete() inline in iomap_dio_rw() providing its return value
to the caller as for ordinary sync IO.
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>

Pull tracing fixes from Steven Rostedt:
 "A few tracing fixes:

   - Remove lockdown from tracefs itself and moved it to the trace
     directory. Have the open functions there do the lockdown checks.

   - Fix a few races with opening an instance file and the instance
     being deleted (Discovered during the lockdown updates). Kept
     separate from the clean up code such that they can be backported to
     stable easier.

   - Clean up and consolidated the checks done when opening a trace
     file, as there were multiple checks that need to be done, and it
     did not make sense having them done in each open instance.

   - Fix a regression in the record mcount code.

   - Small hw_lat detector tracer fixes.

   - A trace_pipe read fix due to not initializing trace_seq"

* tag 'trace-v5.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Initialize iter->seq after zeroing in tracing_read_pipe()
  tracing/hwlat: Don't ignore outer-loop duration when calculating max_latency
  tracing/hwlat: Report total time spent in all NMIs during the sample
  recordmcount: Fix nop_mcount() function
  tracing: Do not create tracefs files if tracefs lockdown is in effect
  tracing: Add locked_down checks to the open calls of files created for tracefs
  tracing: Add tracing_check_open_get_tr()
  tracing: Have trace events system open call tracing_open_generic_tr()
  tracing: Get trace_array reference for available_tracers files
  ftrace: Get a reference counter for the trace_array on filter files
  tracefs: Revert ccbd54ff ("tracefs: Restrict tracefs when the kernel is locked down")

Merge tag 'hwmon-for-v5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:

 - Update/fix inspur-ipsps1 and k10temp Documentation

 - Fix nct7904 driver

 - Fix HWMON_P_MIN_ALARM mask in hwmon core

* tag 'hwmon-for-v5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: docs: Extend inspur-ipsps1 title underline
  hwmon: (nct7904) Add array fan_alarm and vsen_alarm to store the alarms in nct7904_data struct.
  docs: hwmon: Include 'inspur-ipsps1.rst' into docs
  hwmon: Fix HWMON_P_MIN_ALARM mask
  hwmon: (k10temp) Update documentation and add temp2_input info
  hwmon: (nct7904) Fix the incorrect value of vsen_mask in nct7904_data struct

Pull MTD fixes from Richard Weinberger:
 "Two fixes for MTD:

   - spi-nor: Fix for a regression in write_sr()

   - rawnand: Regression fix for the au1550nd driver"

* tag 'fixes-for-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd: rawnand: au1550nd: Fix au_read_buf16() prototype
  mtd: spi-nor: Fix direction of the write_sr() transfer

Pull io_uring fix from Jens Axboe:
 "Single small fix for a regression in the sequence logic for linked
  commands"

* tag 'for-linus-20191012' of git://git.kernel.dk/linux-block:
  io_uring: fix sequence logic for timeout requests

A customer reported the following softlockup:

[899688.160002] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [test.sh:16464]
[899688.160002] CPU: 0 PID: 16464 Comm: test.sh Not tainted 4.12.14-6.23-azure #1 SLE12-SP4
[899688.160002] RIP: 0010:up_write+0x1a/0x30
[899688.160002] Kernel panic - not syncing: softlockup: hung tasks
[899688.160002] RIP: 0010:up_write+0x1a/0x30
[899688.160002] RSP: 0018:ffffa86784d4fde8 EFLAGS: 00000257 ORIG_RAX: ffffffffffffff12
[899688.160002] RAX: ffffffff970fea00 RBX: 0000000000000001 RCX: 0000000000000000
[899688.160002] RDX: ffffffff00000001 RSI: 0000000000000080 RDI: ffffffff970fea00
[899688.160002] RBP: ffffffffffffffff R08: ffffffffffffffff R09: 0000000000000000
[899688.160002] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8b59014720d8
[899688.160002] R13: ffff8b59014720c0 R14: ffff8b5901471090 R15: ffff8b5901470000
[899688.160002]  tracing_read_pipe+0x336/0x3c0
[899688.160002]  __vfs_read+0x26/0x140
[899688.160002]  vfs_read+0x87/0x130
[899688.160002]  SyS_read+0x42/0x90
[899688.160002]  do_syscall_64+0x74/0x160

It caught the process in the middle of trace_access_unlock(). There is
no loop. So, it must be looping in the caller tracing_read_pipe()
via the "waitagain" label.

Crashdump analyze uncovered that iter->seq was completely zeroed
at this point, including iter->seq.seq.size. It means that
print_trace_line() was never able to print anything and
there was no forward progress.

The culprit seems to be in the code:

	/* reset all but tr, trace, and overruns */
	memset(&iter->seq, 0,
	       sizeof(struct trace_iterator) -
	       offsetof(struct trace_iterator, seq));

It was added by the commit 53d0aa77 ("ftrace:
add logic to record overruns"). It was v2.6.27-rc1.
It was the time when iter->seq looked like:

     struct trace_seq {
	unsigned char		buffer[PAGE_SIZE];
	unsigned int		len;
     };

There was no "size" variable and zeroing was perfectly fine.

The solution is to reinitialize the structure after or without
zeroing.

Link: http://lkml.kernel.org/r/20191011142134.11997-1-pmladek@suse.comSigned-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

max_latency is intended to record the maximum ever observed hardware
latency, which may occur in either part of the loop (inner/outer). So
we need to also consider the outer-loop sample when updating
max_latency.

Link: http://lkml.kernel.org/r/157073345463.17189.18124025522664682811.stgit@srivatsa-ubuntu

Fixes: e7c15cd8 ("tracing: Added hardware latency tracer")
Cc: stable@vger.kernel.org
Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>