Merge tag 'rename-eofblocks-5.14_2021-06-08' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-5.14-merge2

xfs: rename struct xfs_eofblocks

In the old days, struct xfs_eofblocks was an optional parameter to the
speculative post-EOF allocation garbage collector to narrow the scope of
a scan to files fitting specific criteria.  Nowadays it is used for all
other kinds of inode cache walks (reclaim, quotaoff, inactivation), so
the name is no longer fitting.  Change the flag namespace and rename the
structure to something more appropriate for what it does.

v2: separate the inode cache walk flag namespace from eofblocks

* tag 'rename-eofblocks-5.14_2021-06-08' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
  xfs: rename struct xfs_eofblocks to xfs_icwalk
  xfs: change the prefix of XFS_EOF_FLAGS_* to XFS_ICWALK_FLAG_

Merge tag 'fix-inode-health-reports-5.14_2021-06-08' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-5.14-merge2

xfs: preserve inode health reports for longer

This is a quick series to make sure that inode sickness reports stick
around in memory for some amount of time.

v2: rebase to 5.13-rc4
v3: require explicit request to reclaim sick inodes, drop weird icache
    miss interaction with DONTCACHE

* tag 'fix-inode-health-reports-5.14_2021-06-08' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
  xfs: selectively keep sick inodes in memory
  xfs: drop IDONTCACHE on inodes when we mark them sick
  xfs: only reset incore inode health state flags when reclaiming an inode

The xfs_eofblocks structure is no longer well-named -- nowadays it
provides optional filtering criteria to any walk of the incore inode
cache.  Only one of the cache walk goals has anything to do with
clearing of speculative post-EOF preallocations, so change the name to
be more appropriate.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

It's important that the filesystem retain its memory of sick inodes for
a little while after problems are found so that reports can be collected
about what was wrong.  Don't let inode reclamation free sick inodes
unless we're unmounting or the fs already went down.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

In preparation for renaming struct xfs_eofblocks to struct xfs_icwalk,
change the prefix of the existing XFS_EOF_FLAGS_* flags to
XFS_ICWALK_FLAG_ and convert all the existing users.  This adds a degree
of interface separation between the ioctl definitions and the incore
parameters.  Since FLAGS_UNION is only used in xfs_icache.c, move it
there as a private flag.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

When we decide to mark an inode sick, clear the DONTCACHE flag so that
the incore inode will be kept around until memory pressure forces it out
of memory.  This increases the chances that the sick status will be
caught by someone compiling a health report later on.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

While running some fuzz tests on inode metadata, I noticed that the
filesystem health report (as provided by xfs_spaceman) failed to report
the file corruption even when spaceman was run immediately after running
xfs_scrub to detect the corruption.  That isn't the intended behavior;
one ought to be able to run scrub to detect errors in the ondisk
metadata and be able to access to those reports for some time after the
scrub.

After running the same sequence through an instrumented kernel, I
discovered the reason why -- scrub igets the file, scans it, marks it
sick, and ireleases the inode.  When the VFS lets go of the incore
inode, it moves to RECLAIMABLE state.  If spaceman igets the incore
inode before it moves to RECLAIM state, iget reinitializes the VFS
state, clears the sick and checked masks, and hands back the inode.  At
this point, the caller has the exact same incore inode, but with all the
health state erased.

In other words, we're erasing the incore inode's health state flags when
we've decided NOT to sever the link between the incore inode and the
ondisk inode.  This is wrong, so we need to remove the lines that zero
the fields from xfs_iget_cache_hit.

As a precaution, we add the same lines into xfs_reclaim_inode just after
we sever the link between incore and ondisk inode.  Strictly speaking
this isn't necessary because once an inode has gone through reclaim it
must go through xfs_inode_alloc (which also zeroes the state) and
xfs_iget is careful to check for mismatches between the inode it pulls
out of the radix tree and the one it wants.

Fixes: 6772c1f1 ("xfs: track metadata health status")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>

Merge tag 'inode-walk-cleanups-5.14_2021-06-03' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-5.14-merge2

xfs: clean up incore inode walk functions

This ambitious series aims to cleans up redundant inode walk code in
xfs_icache.c, hide implementation details of the quotaoff dquot release
code, and eliminates indirect function calls from incore inode walks.

The first thing it does is to move all the code that quotaoff calls to
release dquots from all incore inodes into xfs_icache.c.  Next, it
separates the goal of an inode walk from the actual radix tree tags that
may or may not be involved and drops the kludgy XFS_ICI_NO_TAG thing.
Finally, we split the speculative preallocation (blockgc) and quotaoff
dquot release code paths into separate functions so that we can keep the
implementations cohesive.

Christoph suggested last cycle that we 'simply' change quotaoff not to
allow deactivating quota entirely, but as these cleanups are to enable
one major change in behavior (deferred inode inactivation) I do not want
to add a second behavior change (quotaoff) as a dependency.

To be blunt: Additional cleanups are not in scope for this series.

Next, I made two observations about incore inode radix tree walks --
since there's a 1:1 mapping between the walk goal and the per-inode
processing function passed in, we can use the goal to make a direct call
to the processing function.  Furthermore, the only caller to supply a
nonzero iter_flags argument is quotaoff, and there's only one INEW flag.

From that observation, I concluded that it's quite possible to remove
two parameters from the xfs_inode_walk* function signatures -- the
iter_flags, and the execute function pointer.  The middle of the series
moves the INEW functionality into the one piece (quotaoff) that wants
it, and removes the indirect calls.

The final observation is that the inode reclaim walk loop is now almost
the same as xfs_inode_walk, so it's silly to maintain two copies.  Merge
the reclaim loop code into xfs_inode_walk.

Lastly, refactor the per-ag radix tagging functions since there's
duplicated code that can be consolidated.

This series is a prerequisite for the next two patchsets, since deferred
inode inactivation will add another inode radix tree tag and iterator
function to xfs_inode_walk.

v2: walk the vfs inode list when running quotaoff instead of the radix
    tree, then rework the (now completely internal) inode walk function
    to take the tag as the main parameter.
v3: merge the reclaim loop into xfs_inode_walk, then consolidate the
    radix tree tagging functions
v4: rebase to 5.13-rc4
v5: combine with the quotaoff patchset, reorder functions to minimize
    forward declarations, split inode walk goals from radix tree tags
    to reduce conceptual confusion
v6: start moving the inode cache code towards the xfs_icwalk prefix

* tag 'inode-walk-cleanups-5.14_2021-06-03' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
  xfs: refactor per-AG inode tagging functions
  xfs: merge xfs_reclaim_inodes_ag into xfs_inode_walk_ag
  xfs: pass struct xfs_eofblocks to the inode scan callback
  xfs: fix radix tree tag signs
  xfs: make the icwalk processing functions clean up the grab state
  xfs: clean up inode state flag tests in xfs_blockgc_igrab
  xfs: remove indirect calls from xfs_inode_walk{,_ag}
  xfs: remove iter_flags parameter from xfs_inode_walk_*
  xfs: move xfs_inew_wait call into xfs_dqrele_inode
  xfs: separate the dqrele_all inode grab logic from xfs_inode_walk_ag_grab
  xfs: pass the goal of the incore inode walk to xfs_inode_walk()
  xfs: rename xfs_inode_walk functions to xfs_icwalk
  xfs: move the inode walk functions further down
  xfs: detach inode dquots at the end of inactivation
  xfs: move the quotaoff dqrele inode walk into xfs_icache.c

[djwong: added variable names to function declarations while fixing
merge conflicts]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

Merge tag 'assorted-fixes-5.14-1_2021-06-03' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-5.14-merge2

xfs: assorted fixes for 5.14, part 1

This branch contains the first round of various small fixes for 5.14.

* tag 'assorted-fixes-5.14-1_2021-06-03' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
  xfs: don't take a spinlock unconditionally in the DIO fastpath
  xfs: mark xfs_bmap_set_attrforkoff static
  xfs: Remove redundant assignment to busy
  xfs: sort variable alphabetically to avoid repeated declaration

Merge tag 'unit-conversion-cleanups-5.14_2021-06-03' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-5.14-merge2

xfs: various unit conversions

Crafting the realtime file extent size hint fixes revealed various
opportunities to clean up unit conversions, so now that gets its own
series.

* tag 'unit-conversion-cleanups-5.14_2021-06-03' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
  xfs: remove unnecessary shifts
  xfs: clean up open-coded fs block unit conversions

From: Dave Chinner <dchinner@redhat.com>

Stephen Rothwell reported this compiler warning from linux-next:

fs/xfs/libxfs/xfs_ialloc.c: In function 'xfs_difree_finobt':
fs/xfs/libxfs/xfs_ialloc.c:2032:20: warning: unused variable 'agi' [-Wunused-variable]
 2032 |  struct xfs_agi   *agi = agbp->b_addr;

Which is fallout from agno -> perag conversions that were done in
this function. xfs_check_agi_freecount() is the only user of "agi"
in xfs_difree_finobt() now, and it only uses the agi to get the
current free inode count. We hold that in the perag structure, so
there's not need to directly reference the raw AGI to get this
information.

The btree cursor being passed to xfs_check_agi_freecount() has a
reference to the perag being operated on, so use that directly in
xfs_check_agi_freecount() rather than passing an AGI.

Fixes: 7b13c515 ("xfs: use perag for ialloc btree cursors")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

Merge tag 'xfs-perag-conv-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs into xfs-5.14-merge2

xfs: initial agnumber -> perag conversions for shrink

If we want to use active references to the perag to be able to gate
shrink removing AGs and hence perags safely, we've got a fair bit of
work to do actually use perags in all the places we need to.

There's a lot of code that iterates ag numbers and then
looks up perags from that, often multiple times for the same perag
in the one operation. If we want to use reference counted perags for
access control, then we need to convert all these uses to perag
iterators, not agno iterators.

[Patches 1-4]

The first step of this is consolidating all the perag management -
init, free, get, put, etc into a common location. THis is spread all
over the place right now, so move it all into libxfs/xfs_ag.[ch].
This does expose kernel only bits of the perag to libxfs and hence
userspace, so the structures and code is rearranged to minimise the
number of ifdefs that need to be added to the userspace codebase.
The perag iterator in xfs_icache.c is promoted to a first class API
and expanded to the needs of the code as required.

[Patches 5-10]

These are the first basic perag iterator conversions and changes to
pass the perag down the stack from those iterators where
appropriate. A lot of this is obvious, simple changes, though in
some places we stop passing the perag down the stack because the
code enters into an as yet unconverted subsystem that still uses raw
AGs.

[Patches 11-16]

These replace the agno passed in the btree cursor for per-ag btree
operations with a perag that is passed to the cursor init function.
The cursor takes it's own reference to the perag, and the reference
is dropped when the cursor is deleted. Hence we get reference
coverage for the entire time the cursor is active, even if the code
that initialised the cursor drops it's reference before the cursor
or any of it's children (duplicates) have been deleted.

The first patch adds the perag infrastructure for the cursor, the
next four patches convert a btree cursor at a time, and the last
removes the agno from the cursor once it is unused.

[Patches 17-21]

These patches are a demonstration of the simplifications and
cleanups that come from plumbing the perag through interfaces that
select and then operate on a specific AG. In this case the inode
allocation algorithm does up to three walks across all AGs before it
either allocates an inode or fails. Two of these walks are purely
just to select the AG, and even then it doesn't guarantee inode
allocation success so there's a third walk if the selected AG
allocation fails.

These patches collapse the selection and allocation into a single
loop, simplifies the error handling because xfs_dir_ialloc() always
returns ENOSPC if no AG was selected for inode allocation or we fail
to allocate an inode in any AG, gets rid of xfs_dir_ialloc()
wrapper, converts inode allocation to run entirely from a single
perag instance, and then factors xfs_dialloc() into a much, much
simpler loop which is easy to understand.

Hence we end up with the same inode allocation logic, but it only
needs two complete iterations at worst, makes AG selection and
allocation atomic w.r.t. shrink and chops out out over 100 lines of
code from this hot code path.

[Patch 22]

Converts the unlink path to pass perags through it.

There's more conversion work to be done, but this patchset gets
through a large chunk of it in one hit. Most of the iterators are
converted, so once this is solidified we can move on to converting
these to active references for being able to free perags while the
fs is still active.

* tag 'xfs-perag-conv-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (23 commits)
  xfs: remove xfs_perag_t
  xfs: use perag through unlink processing
  xfs: clean up and simplify xfs_dialloc()
  xfs: inode allocation can use a single perag instance
  xfs: get rid of xfs_dir_ialloc()
  xfs: collapse AG selection for inode allocation
  xfs: simplify xfs_dialloc_select_ag() return values
  xfs: remove agno from btree cursor
  xfs: use perag for ialloc btree cursors
  xfs: convert allocbt cursors to use perags
  xfs: convert refcount btree cursor to use perags
  xfs: convert rmap btree cursor to using a perag
  xfs: add a perag to the btree cursor
  xfs: pass perags around in fsmap data dev functions
  xfs: push perags through the ag reservation callouts
  xfs: pass perags through to the busy extent code
  xfs: convert secondary superblock walk to use perags
  xfs: convert xfs_iwalk to use perag references
  xfs: convert raw ag walks to use for_each_perag
  xfs: make for_each_perag... a first class citizen
  ...

Merge tag 'xfs-buf-bulk-alloc-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs into xfs-5.14-merge2

xfs: buffer cache bulk page allocation

This patchset makes use of the new bulk page allocation interface to
reduce the overhead of allocating large numbers of pages in a
loop.

The first two patches are refactoring buffer memory allocation and
converting the uncached buffer path to use the same page allocation
path, followed by converting the page allocation path to use bulk
allocation.

The rest of the patches are then consolidation of the page
allocation and freeing code to simplify the code and remove a chunk
of unnecessary abstraction. This is largely based on a series of
changes made by Christoph Hellwig.

* tag 'xfs-buf-bulk-alloc-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
  xfs: merge xfs_buf_allocate_memory
  xfs: cleanup error handling in xfs_buf_get_map
  xfs: get rid of xb_to_gfp()
  xfs: simplify the b_page_count calculation
  xfs: remove ->b_offset handling for page backed buffers
  xfs: move page freeing into _xfs_buf_free_pages()
  xfs: merge _xfs_buf_get_pages()
  xfs: use alloc_pages_bulk_array() for buffers
  xfs: use xfs_buf_alloc_pages for uncached buffers
  xfs: split up xfs_buf_allocate_memory

It only has one caller and is now a simple function, so merge it
into the caller.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

Use a single goto label for freeing the buffer and returning an
error.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <dchinner@redhat.com>

Only used in one place, so just open code the logic in the macro.
Based on a patch from Christoph Hellwig.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

Ever since we stopped using the Linux page cache to back XFS buffers
there is no need to take the start sector into account for
calculating the number of pages in a buffer, as the data always
start from the beginning of the buffer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
[dgc: modified to suit this series]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

->b_offset can only be non-zero for _XBF_KMEM backed buffers, so
remove all code dealing with it for page backed buffers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
[dgc: modified to fit this patchset]
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

In preparation for adding another incore inode tree tag, refactor the
code that sets and clears tags from the per-AG inode tree and the tree
of per-AG structures, and remove the open-coded versions used by the
blockgc code.

Note: For reclaim, we now rely on the radix tree tags instead of the
reclaimable inode count more heavily than we used to.  The conversion
should be fine, but the logic isn't 100% identical.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Merge these two inode walk loops together, since they're pretty similar
now.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Pass a pointer to the actual eofb structure around the inode scanner
functions instead of a void pointer, now that none of the functions is
used as a callback.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Radix tree tags are supposed to be unsigned ints, so fix the callers.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Soon we're going to be adding two new callers to the incore inode walk
code: reclaim of incore inodes, and (later) inactivation of inodes.
Both states operate on inodes that no longer have any VFS state, so we
need to move the xfs_irele calls into the processing functions.

In other words, icwalk processing functions are responsible for cleaning
up whatever state changes are made by the corresponding icwalk igrab
function that picked the inode for processing.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Clean up the definition of which inode states are not eligible for
speculative preallocation garbage collecting by creating a private
#define.  The deferred inactivation patchset will add two new entries to
the set of flags-to-ignore, so we want the definition not to end up a
cluttered mess.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

It turns out that there is a 1:1 mapping between the execute and goal
parameters that are passed to xfs_inode_walk_ag:

	xfs_blockgc_scan_inode <=> XFS_ICWALK_BLOCKGC
	xfs_dqrele_inode <=> XFS_ICWALK_DQRELE

Because of this exact correspondence, we don't need the execute function
pointer and can replace it with a direct call.

For the price of a forward static declaration, we can eliminate the
indirect function call.  This likely has a negligible impact on
performance (since the execute function runs transactions), but it also
simplifies the function signature.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

The sole iter_flags is XFS_INODE_WALK_INEW_WAIT, and there are no users.
Remove the flag, and the parameter, and all the code that used it.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Move the INEW wait into xfs_dqrele_inode so that we can drop the
iter_flags parameter in the next patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Disentangle the dqrele_all inode grab code from the "generic" inode walk
grabbing code, and and use the opportunity to document why the dqrele
grab function does what it does.  Since xfs_inode_walk_ag_grab is now
only used for blockgc, rename it to reflect that.

Ultimately, there will be four reasons to perform a walk of incore
inodes: quotaoff dquote releasing (dqrele), garbage collection of
speculative preallocations (blockgc), reclamation of incore inodes
(reclaim), and deferred inactivation (inodegc).  Each of these four have
their own slightly different criteria for deciding if they want to
handle an inode, so it makes more sense to have four cohesive igrab
functions than one confusing parameteric grab function like we do now.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

As part of removing the indirect calls and radix tag implementation
details from the incore inode walk loop, create an enum to represent the
goal of the inode iteration.  More immediately, this separate removes
the need for the "ICI_NOTAG" define which makes little sense.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Shorten the prefix so that all the incore inode cache walk code has
"xfs_icwalk" in the name somewhere.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Move the inode walk functions further down in the file to limit the
forward declarations to the two walk functions as we add new code that
uses the inode walks.  We'll clean them out later (i.e. after the
deferred inode inactivation series).
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Once we're done with inactivating an inode, we're finished updating
metadata for that inode.  This means that we can detach the dquots at
the end and not have to wait for reclaim to do it for us.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

The only external caller of xfs_inode_walk* happens in quotaoff, when we
want to walk all the incore inodes to detach the dquots.  Move this code
to xfs_icache.c so that we can hide xfs_inode_walk as the starting step
in more cleanups of inode walks.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Because this happens at high thread counts on high IOPS devices
doing mixed read/write AIO-DIO to a single file at about a million
iops:

   64.09%     0.21%  [kernel]            [k] io_submit_one
   - 63.87% io_submit_one
      - 44.33% aio_write
         - 42.70% xfs_file_write_iter
            - 41.32% xfs_file_dio_write_aligned
               - 25.51% xfs_file_write_checks
                  - 21.60% _raw_spin_lock
                     - 21.59% do_raw_spin_lock
                        - 19.70% __pv_queued_spin_lock_slowpath

This also happens of the IO completion IO path:

   22.89%     0.69%  [kernel]            [k] xfs_dio_write_end_io
   - 22.49% xfs_dio_write_end_io
      - 21.79% _raw_spin_lock
         - 20.97% do_raw_spin_lock
            - 20.10% __pv_queued_spin_lock_slowpath

IOWs, fio is burning ~14 whole CPUs on this spin lock.

So, do an unlocked check against inode size first, then if we are
at/beyond EOF, take the spinlock and recheck. This makes the
spinlock disappear from the overwrite fastpath.

I'd like to report that fixing this makes things go faster. It
doesn't - it just exposes the the XFS_ILOCK as the next severe
contention point doing extent mapping lookups, and that now burns
all the 14 CPUs this spinlock was burning.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

xfs_bmap_set_attrforkoff is only used inside of xfs_bmap.c, so mark it
static.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

Variable busy is set to false, but this value is never read as it is
overwritten or not used later on, hence it is a redundant assignment
and can be removed.

Clean up the following clang-analyzer warning:

fs/xfs/libxfs/xfs_alloc.c:1679:2: warning: Value stored to 'busy' is
never read [clang-analyzer-deadcode.DeadStores].
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

Variable 'xfs_agf_buf_ops', 'xfs_agi_buf_ops', 'xfs_dquot_buf_ops' and
'xfs_symlink_buf_ops' are declared twice, so sort these variables
alphabetically and remove the repeated declaration.

Cc: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Shaokun Zhang <zhangshaokun@hisilicon.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

Almost unused, gets rid of another typedef.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

Unlinked lists are held in the perag, and freeing of inodes needs to
be passed a perag, too, so look up the perag early in the unlink
processing and use it throughout.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Because it's a mess.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>