linux.git/fs/xfs/libxfs, branch v5.2

xfs: don't reserve per-AG space for an internal log

2019-05-20T18:25:39+00:00

It turns out that the log can consume nearly all the space in an AG, and
when this happens this it's possible that there will be less free space
in the AG than the reservation would try to hide.  On a debug kernel
this can trigger an ASSERT in xfs/250:

XFS: Assertion failed: xfs_perag_resv(pag, XFS_AG_RESV_METADATA)->ar_reserved + xfs_perag_resv(pag, XFS_AG_RESV_RMAPBT)->ar_reserved <= pag->pagf_freeblks + pag->pagf_flcount, file: fs/xfs/libxfs/xfs_ag_resv.c, line: 319

The log is permanently allocated, so we know we're never going to have
to expand the btrees to hold any records associated with the log space.
We therefore can treat the space as if it doesn't exist.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Eric Sandeen

xfs: change some error-less functions to void types

2019-05-02T03:26:30+00:00

There are several functions which have no opportunity to return
an error, and don't contain any ASSERTs which could be argued
to be better constructed as error cases.  So, make them voids
to simplify the callers.

Signed-off-by: Eric Sandeen 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong 
Reviewed-by: Dave Chinner

xfs: add online scrub for superblock counters

2019-04-30T15:19:13+00:00

Teach online scrub how to check the filesystem summary counters.  We use
the incore delalloc block counter along with the incore AG headers to
compute expected values for fdblocks, icount, and ifree, and then check
that the percpu counter is within a certain threshold of the expected
value.  This is done to avoid having to freeze or otherwise lock the
filesystem, which means that we're only checking that the counters are
fairly close, not that they're exactly correct.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Dave Chinner 
Reviewed-by: Brian Foster

xfs: always rejoin held resources during defer roll

2019-04-30T15:19:13+00:00

During testing of xfs/141 on a V4 filesystem, I observed some
inconsistent behavior with regards to resources that are held (i.e.
remain locked) across a defer roll.  The transaction roll always gives
the defer roll function a new transaction, even if committing the old
transaction fails.  However, the defer roll function only rejoins the
held resources if the transaction commit succeedied.  This means that
callers of defer roll have to figure out whether the held resources are
attached to the transaction being passed back.

Worse yet, if the defer roll was part of a defer finish call, we have a
third possibility: the defer finish could pass back a dirty transaction
with dirty held resources and an error code.

The only sane way to handle all of these scenarios is to require that
the code that held the resource either cancel the transaction before
unlocking and releasing the resources, or use functions that detach
resources from a transaction properly (e.g.  xfs_trans_brelse) if they
need to drop the reference before committing or cancelling the
transaction.

In order to make this so, change the defer roll code to join held
resources to the new transaction unconditionally and fix all the bhold
callers to release the held buffers correctly.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Brian Foster

xfs: track delayed allocation reservations across the filesystem

2019-04-26T19:28:55+00:00

Add a percpu counter to track the number of blocks directly reserved for
delayed allocations on the data device.  This counter (in contrast to
i_delayed_blks) does not track allocated CoW staging extents or anything
going on with the realtime device.  It will be used in the upcoming
summary counter scrub function to check the free block counts without
having to freeze the filesystem or walk all the inodes to find the
delayed allocations.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Dave Chinner

xfs: assert that we don't enter agfl freeing with a non-permanent transaction

2019-04-23T15:36:23+00:00

Block allocation requires a permanent transaction for deferred AGFL
frees.  Add an assert in the block allocation path to make explicit and
obvious to future callers the requirement of a transaction with a
permanent reservation.

Reported-by: Darrick J. Wong 
Signed-off-by: Brian Foster 
Reviewed-by: Darrick J. Wong 
[darrick: split this out from the previous patch per hch request]
Signed-off-by: Darrick J. Wong

xfs: make tr_growdata a permanent transaction

2019-04-22T23:28:45+00:00

The growdata transaction is used by growfs operations to increase
the data size of the filesystem. Part of this sequence involves
extending the size of the last preexisting AG in the fs, if
necessary. This is implemented by freeing the newly available
physical range to the AG.

tr_growdata is not a permanent transaction, however, and block
allocation transactions must be permanent to handle deferred frees
of AGFL blocks. If the grow operation extends an existing AG that
requires AGFL fixing, assert failures occur due to a populated dfops
list on a non-permanent transaction and the AGFL free does not
occur. This is reproduced (rarely) by xfs/104.

Change tr_growdata to a permanent transaction with a default log
count. This increases initial transaction reservation size, but
growfs is an infrequent and non-performance critical operation and
so should have minimal impact.

Reported-by: Darrick J. Wong 
Signed-off-by: Brian Foster 
Reviewed-by: Darrick J. Wong 
[darrick: add a comment to the assert]
Signed-off-by: Darrick J. Wong

xfs: report inode health via bulkstat

2019-04-15T01:15:58+00:00

Use space in the bulkstat ioctl structure to report any problems
observed with the inode.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Brian Foster

xfs: report AG health via AG geometry ioctl

2019-04-15T01:15:57+00:00

Use the AG geometry info ioctl to report health status too.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Brian Foster

xfs: report fs and rt health via geometry structure

2019-04-15T01:15:57+00:00

Use our newly expanded geometry structure to report the overall fs and
realtime health status.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Brian Foster