When CONFIG_XFS_DEBUG=y, set WQ_SYSFS on all workqueues that we create
so that we (developers) have a means to monitor cpu affinity and whatnot
for background workers.  In the next patchset we'll expose knobs for
more of the workqueues publicly and document it, but not now.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Increase the parallelism level for pwork clients to the workqueue
defaults so that we can take advantage of computers with a lot of CPUs
and a lot of hardware.  On fast systems this will speed up quotacheck by
a large factor, and the following posteof/cowblocks cleanup series will
use the functionality presented in this patch to run garbage collection
as quickly as possible.

We do this by switching the pwork workqueue to unbounded, since the
current user (quotacheck) runs lengthy scans for each work item and we
don't care about dispatching the work on a warm cpu cache or anything
like that.  Also set WQ_SYSFS so that we can monitor where the wq is
running.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

If a fs modification (creation, file write, reflink, etc.) is unable to
reserve enough space to handle the modification, try clearing whatever
space the filesystem might have been hanging onto in the hopes of
speeding up the filesystem.  The flushing behavior will become
particularly important when we add deferred inode inactivation because
that will increase the amount of space that isn't actively tied to user
data.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

In anticipation of more restructuring of the eof/cowblocks gc code,
refactor calling of those two functions into a single internal helper
function, then present a new standard interface to purge speculative
block preallocations and start shifting higher level code to use that.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Add some tracepoints so that we can observe when the speculative
preallocation garbage collector runs.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

If a file user, group, or project change is unable to reserve enough
quota to handle the modification, try clearing whatever space the
filesystem might have been hanging onto in the hopes of speeding up the
filesystem.  The flushing behavior will become particularly important
when we add deferred inode inactivation because that will increase the
amount of space that isn't actively tied to user data.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

If an inode creation is unable to reserve enough quota to handle the
modification, try clearing whatever space the filesystem might have been
hanging onto in the hopes of speeding up the filesystem.  The flushing
behavior will become particularly important when we add deferred inode
inactivation because that will increase the amount of space that isn't
actively tied to user data.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

If a fs modification (data write, reflink, xattr set, fallocate, etc.)
is unable to reserve enough quota to handle the modification, try
clearing whatever space the filesystem might have been hanging onto in
the hopes of speeding up the filesystem.  The flushing behavior will
become particularly important when we add deferred inode inactivation
because that will increase the amount of space that isn't actively tied
to user data.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Now that we've converted xfs_reflink_remap_extent to use the new
xfs_trans_alloc_inode API, we can focus on its slightly unusual behavior
with regard to quota reservations.

Since it's valid to remap written blocks into a hole, we must be able to
increase the quota count by the number of blocks in the mapping.
However, the incore space reservation process requires us to supply an
asymptotic guess before we can gain exclusive access to resources.  We'd
like to reserve all the quota we need up front, but we also don't want
to fail a written -> allocated remap operation unnecessarily.

The solution is to make the remap_extents function call the transaction
allocation function twice.  The first time we ask to reserve enough
space and quota to handle the absolute worst case situation, but if that
fails, we can fall back to the old strategy: ask for the bare minimum
space reservation upfront and increase the quota reservation later if we
need to.

Later in this patchset we change the transaction and quota code to try
to reclaim space if we cannot reserve free space or quota.
Restructuring the remap_extent function in this manner means that if the
fallback increase fails, we can pass that back to the caller knowing
that the transaction allocation already tried freeing space.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Change the signature of xfs_blockgc_free_quota in preparation for the
next few patches.  Callers can now pass EOF_FLAGS into the function to
control scan parameters; and the function will now pass back any
corruption errors seen while scanning, though for our retry loops we'll
just try again unconditionally.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Move this function further down in the file so that later cleanups won't
have to declare static functions.  Change the name because we're about
to rework all the code that performs garbage collection of speculatively
allocated file blocks.  No functional changes.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Buffered writers who have run out of quota reservation call
xfs_inode_free_quota_blocks to try to free any space reservations that
might reduce the quota usage.  Unfortunately, the buffered write path
treats "out of project quota" the same as "out of overall space" so this
function has never supported scanning for space that might ease an "out
of project quota" condition.

We're about to start using this function for cases where we actually
/can/ tell if we're out of project quota, so add in this functionality.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Don't stall the cowblocks scan on a locked inode if we possibly can.
We'd much rather the background scanner keep moving.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

The functions to run an eof/cowblocks scan to try to reduce quota usage
are kind of a mess -- the logic repeatedly initializes an eofb structure
and there are logic bugs in the code that result in the cowblocks scan
never actually happening.

Replace all three functions with a single function that fills out an
eofb and runs both eof and cowblocks scans.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

If we ever screw up the quota reservations enough to trip the
assertions, something's wrong with the quota code.  Shut down the
filesystem when this happens, because this is corruption.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Rename the 'code' variable to 'error' to follow the naming convention of
most other functions in xfs.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Now that the only caller of this function is xfs_trans_alloc_ichange,
just open-code the meat of _chown_reserve in that caller.  Drop the
(redundant) [ugp]id checks because xfs has a 1:1 relationship between
quota ids and incore dquots.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

For file ownership (uid, gid, prid) changes, create a new helper
xfs_trans_alloc_ichange that allocates a transaction and reserves the
appropriate amount of quota against that transction in preparation for a
change of user, group, or project id.  Replace all the open-coded idioms
with a single call to this helper so that we can contain the retry loops
in the next patchset.

This changes the locking behavior for ichange transactions slightly.
Since tr_ichange does not have a permanent reservation and cannot roll,
we pass XFS_ILOCK_EXCL to ijoin so that the inode will be unlocked
automatically at commit time.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

For file creation, create a new helper xfs_trans_alloc_icreate that
allocates a transaction and reserves the appropriate amount of quota
against that transction.  Replace all the open-coded idioms with a
single call to this helper so that we can contain the retry loops in the
next patchset.

This changes the locking behavior for non-tempfile creation slightly, in
that we now make the quota reservation without holding the directory
ILOCK.  While the dquots chosen for inode creation are based on the
directory state at a given point in time, the directory ILOCK was
released as soon as the dquot references are picked up.  Hence it was
never necessary to hold the directory ILOCK for the quota reservation.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

The two remaining callers of xfs_trans_reserve_quota_nblks are in the
reflink code.  These conversions aren't as uniform as the previous
conversions, so call that out in a separate patch.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

Make it so that we can reserve rt blocks with the xfs_trans_alloc_inode
wrapper function, then convert a few more callsites.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Create a new helper xfs_trans_alloc_inode that allocates a transaction,
locks and joins an inode to it, and then reserves the appropriate amount
of quota against that transction.  Then replace all the open-coded
idioms with a single call to this helper.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Modify xfs_trans_reserve_quota_nblks so that we can reserve data and
realtime blocks from the dquot at the same time.  This change has the
theoretical side effect that for allocations to realtime files we will
reserve from the dquot both the number of rtblocks being allocated and
the number of bmbt blocks that might be needed to add the mapping.
However, since the mount code disables quota if it finds a realtime
device, this should not result in any behavior changes.

Now that we've moved the inode creation callers away from using the
_nblks function, we can repurpose the (now unused) ninos argument for
realtime blocks, so make that change.  This also replaces the flags
argument with a boolean parameter to force the reservation since we
don't need to distinguish between data and rt quota reservations any
more, and the only flag being passed in was FORCE_RES.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Fix some build warnings on gcc 10.2 when quotas are disabled.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Create a proper helper so that inode creation calls can reserve quota
with a dedicated function.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>

xfs_trans_cancel will release all the quota resources that were reserved
on behalf of the transaction, so get rid of the explicit unreserve step.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Create a couple of convenience wrappers for creating and deleting quota
block reservations against future changes.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

Convert a few xfs_trans_*reserve* callsites that are open-coding other
convenience functions.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

In commit 3b0fe478, we reduced the free space requirement to
perform a pre-write unwritten extent conversion on an S_DAX file.  Since
we're not actually allocating any space, the logic goes, we only need
enough reservation to handle shape changes in the bmbt.

The same logic should have been applied to quota -- we're not allocating
any space, so we only need to reserve enough quota to handle the bmbt
shape changes.

Fixes: 3b0fe478 ("xfs: Don't use reserved blocks for data blocks with DAX")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

While refactoring the quota code to create a function to allocate inode
change transactions, I noticed that xfs_qm_vop_chown_reserve does more
than just make reservations: it also *modifies* the incore counts
directly to handle the owner id change for the delalloc blocks.

I then observed that the fssetxattr code continues validating input
arguments after making the quota reservation but before dirtying the
transaction.  If the routine decides to error out, it fails to undo the
accounting switch!  This leads to incorrect quota reservation and
failure down the line.

We can fix this by making the reservation function do only that -- for
the new dquot, it reserves ondisk and delalloc blocks to the
transaction, and the old dquot hangs on to its incore reservation for
now.  Once we actually switch the dquots, we can then update the incore
reservations because we've dirtied the transaction and it's too late to
turn back now.

No fixes tag because this has been broken since the start of git.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>

With both CONFIG_XFS_DEBUG and CONFIG_XFS_WARN disabled, the only reference to
local variable "error" in xfs_bmap_compute_alignments() gets eliminated during
pre-processing stage of the compilation process. This causes the compiler to
generate a "set but not used" warning.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Brian Foster <bfoster@redhat.com>

The log variable is only used in kernels with asserts enabled.
Remove it and open code the dereference to avoid unused variable
warnings.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

If the inode is not pinned by the time fsync is called we don't need the
ilock to protect against concurrent clearing of ili_fsync_fields as the
inode won't need a log flush or clearing of these fields.  Not taking
the iolock allows for full concurrency of fsync and thus O_DSYNC
completions with io_uring/aio write submissions.
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>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Factor out the log syncing logic into two helpers to make the code easier
to read and more maintainable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>

Filesystem freeze cleans the log and immediately redirties it so log
recovery runs if a crash occurs after the filesystem is frozen. Now
that log quiesce covers the log, there is no need to clean the log and
redirty it to trigger log recovery because covering has the same
effect. Update xfs_fs_freeze() to quiesce (and thus cover) the log.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>

xfs_quiesce_attr() is now a wrapper for xfs_log_clean(). Remove it
and call xfs_log_clean() directly.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>

These two calls are repeated at the beginning of xfs_log_quiesce().
Drop them from xfs_quiesce_attr().
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>

xfs_log_sbcount() calls xfs_sync_sb() to sync superblock counters to
disk when lazy superblock accounting is enabled. This occurs on
unmount, freeze, and read-only (re)mount and ensures the final
values are calculated and persisted to disk before each form of
quiesce completes.

Now that log covering occurs in all of these contexts and uses the
same xfs_sync_sb() mechanism to update log state, there is no need
to log the superblock separately for any reason. Update the log
quiesce path to sync the superblock at least once for any mount
where lazy superblock accounting is enabled. If the log is already
covered, it will remain in the covered state. Otherwise, the next
sync as part of the normal covering sequence will carry the
associated superblock update with it. Remove xfs_log_sbcount() now
that it is no longer needed.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>

Now that log covering occurs on quiesce, we'd like to reuse the
underlying superblock sync for final superblock updates. This
includes things like lazy superblock counter updates, log feature
incompat bits in the future, etc. One quirk to this approach is that
once the log is in the IDLE (i.e. already covered) state, any
subsequent log write resets the state back to NEED. This means that
a final superblock sync to an already covered log requires two more
sb syncs to return the log back to IDLE again.

For example, if a lazy superblock enabled filesystem is mount cycled
without any modifications, the unmount path syncs the superblock
once and writes an unmount record. With the desired log quiesce
covering behavior, we sync the superblock three times at unmount
time: once for the lazy superblock counter update and twice more to
cover the log. By contrast, if the log is active or only partially
covered at unmount time, a final superblock sync would doubly serve
as the one or two remaining syncs required to cover the log.

This duplicate covering sequence is unnecessary because the
filesystem remains consistent if a crash occurs at any point. The
superblock will either be recovered in the event of a crash or
written back before the log is quiesced and potentially cleaned with
an unmount record.

Update the log covering state machine to remain in the IDLE state if
additional covering checkpoints pass through the log. This
facilitates final superblock updates (such as lazy superblock
counters) via a single sb sync without losing covered status. This
provides some consistency with the active and partially covered
cases and also avoids harmless, but spurious checkpoints when
quiescing the log.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>

The log quiesce mechanism historically terminates by marking the log
clean with an unmount record. The primary objective is to indicate
that log recovery is no longer required after the quiesce has
flushed all in-core changes and written back filesystem metadata.
While this is perfectly fine, it is somewhat hacky as currently used
in certain contexts. For example, filesystem freeze quiesces (i.e.
cleans) the log and immediately redirties it with a dummy superblock
transaction to ensure that log recovery runs in the event of a
crash.

While this functions correctly, cleaning the log from freeze context
is clearly superfluous given the current redirtying behavior.
Instead, the desired behavior can be achieved by simply covering the
log. This effectively retires all on-disk log items from the active
range of the log by issuing two synchronous and sequential dummy
superblock update transactions that serve to update the on-disk log
head and tail. The subtle difference is that the log technically
remains dirty due to the lack of an unmount record, though recovery
is effectively a no-op due to the content of the checkpoints being
clean (i.e. the unmodified on-disk superblock).

Log covering currently runs in the background and only triggers once
the filesystem and log has idled. The purpose of the background
mechanism is to prevent log recovery from replaying the most
recently logged items long after those items may have been written
back. In the quiesce path, the log has been deliberately idled by
forcing the log and pushing the AIL until empty in a context where
no further mutable filesystem operations are allowed. Therefore, we
can cover the log as the final step in the log quiesce codepath to
reflect that all previously active items have been successfully
written back.

This facilitates selective log covering from certain contexts (i.e.
freeze) that only seek to quiesce, but not necessarily clean the
log. Note that as a side effect of this change, log covering now
occurs when cleaning the log as well. This is harmless, facilitates
subsequent cleanups, and is mostly temporary as various operations
switch to use explicit log covering.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>