mainline-inclusion
from mainline-v5.13-rc4
commit 5f9b4b0d
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4KIAO
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=5f9b4b0de8dc2fb8eb655463b438001c111570fe

-------------------------------------------------

In doing an investigation into AIL push stalls, I was looking at the
log force code to see if an async CIL push could be done instead.
This lead me to xfs_log_force_lsn() and looking at how it works.

xfs_log_force_lsn() is only called from inode synchronisation
contexts such as fsync(), and it takes the ip->i_itemp->ili_last_lsn
value as the LSN to sync the log to. This gets passed to
xlog_cil_force_lsn() via xfs_log_force_lsn() to flush the CIL to the
journal, and then used by xfs_log_force_lsn() to flush the iclogs to
the journal.

The problem is that ip->i_itemp->ili_last_lsn does not store a
log sequence number. What it stores is passed to it from the
->iop_committing method, which is called by xfs_log_commit_cil().
The value this passes to the iop_committing method is the CIL
context sequence number that the item was committed to.

As it turns out, xlog_cil_force_lsn() converts the sequence to an
actual commit LSN for the related context and returns that to
xfs_log_force_lsn(). xfs_log_force_lsn() overwrites it's "lsn"
variable that contained a sequence with an actual LSN and then uses
that to sync the iclogs.

This caused me some confusion for a while, even though I originally
wrote all this code a decade ago. ->iop_committing is only used by
a couple of log item types, and only inode items use the sequence
number it is passed.

Let's clean up the API, CIL structures and inode log item to call it
a sequence number, and make it clear that the high level code is
using CIL sequence numbers and not on-disk LSNs for integrity
synchronisation purposes.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NAllison Henderson <allison.henderson@oracle.com>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NGuo Xuenan <guoxuenan@huawei.com>
Reviewed-by: NLihong Kou <koulihong@huawei.com>
Reviewed-by: NZhang Yi <yi.zhang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

mainline-inclusion
from mainline-v5.12-rc4
commit 6543990a
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4KIAO
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6543990a168acf366f4b6174d7bd46ba15a8a2a6

-------------------------------------------------

Keep the mount superblock counters up to date for !lazysbcount
filesystems so that when we log the superblock they do not need
updating in any way because they are already correct.

It's found by what Zorro reported:
1. mkfs.xfs -f -l lazy-count=0 -m crc=0 $dev
2. mount $dev $mnt
3. fsstress -d $mnt -p 100 -n 1000 (maybe need more or less io load)
4. umount $mnt
5. xfs_repair -n $dev
and I've seen no problem with this patch.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reported-by: NZorro Lang <zlang@redhat.com>
Reviewed-by: NGao Xiang <hsiangkao@redhat.com>
Signed-off-by: NGao Xiang <hsiangkao@redhat.com>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NGuo Xuenan <guoxuenan@huawei.com>
Reviewed-by: NLihong Kou <koulihong@huawei.com>
Reviewed-by: NZhang Yi <yi.zhang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

mainline-inclusion
from mainline-v5.12-rc4
commit 1aec7c3d
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4KIAO
CVE: NA

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=1aec7c3d05670b92b7339b19999009a93808efb9

-------------------------------------------------

In commit f8f2835a we changed the behavior of XFS to use EFIs to
remove blocks from an overfilled AGFL because there were complaints
about transaction overruns that stemmed from trying to free multiple
blocks in a single transaction.

Unfortunately, that commit missed a subtlety in the debug-mode
transaction accounting when a realtime volume is attached.  If a
realtime file undergoes a data fork mapping change such that realtime
extents are allocated (or freed) in the same transaction that a data
device block is also allocated (or freed), we can trip a debugging
assertion.  This can happen (for example) if a realtime extent is
allocated and it is necessary to reshape the bmbt to hold the new
mapping.

When we go to allocate a bmbt block from an AG, the first thing the data
device block allocator does is ensure that the freelist is the proper
length.  If the freelist is too long, it will trim the freelist to the
proper length.

In debug mode, trimming the freelist calls xfs_trans_agflist_delta() to
record the decrement in the AG free list count.  Prior to f8f28 we would
put the free block back in the free space btrees in the same
transaction, which calls xfs_trans_agblocks_delta() to record the
increment in the AG free block count.  Since AGFL blocks are included in
the global free block count (fdblocks), there is no corresponding
fdblocks update, so the AGFL free satisfies the following condition in
xfs_trans_apply_sb_deltas:

	/*
	 * Check that superblock mods match the mods made to AGF counters.
	 */
	ASSERT((tp->t_fdblocks_delta + tp->t_res_fdblocks_delta) ==
	       (tp->t_ag_freeblks_delta + tp->t_ag_flist_delta +
		tp->t_ag_btree_delta));

The comparison here used to be: (X + 0) == ((X+1) + -1 + 0), where X is
the number blocks that were allocated.

After commit f8f28 we defer the block freeing to the next chained
transaction, which means that the calls to xfs_trans_agflist_delta and
xfs_trans_agblocks_delta occur in separate transactions.  The (first)
transaction that shortens the free list trips on the comparison, which
has now become:

(X + 0) == ((X) + -1 + 0)

because we haven't freed the AGFL block yet; we've only logged an
intention to free it.  When the second transaction (the deferred free)
commits, it will evaluate the expression as:

(0 + 0) == (1 + 0 + 0)

and trip over that in turn.

At this point, the astute reader may note that the two commits tagged by
this patch have been in the kernel for a long time but haven't generated
any bug reports.  How is it that the author became aware of this bug?

This originally surfaced as an intermittent failure when I was testing
realtime rmap, but a different bug report by Zorro Lang reveals the same
assertion occuring on !lazysbcount filesystems.

The common factor to both reports (and why this problem wasn't
previously reported) becomes apparent if we consider when
xfs_trans_apply_sb_deltas is called by __xfs_trans_commit():

	if (tp->t_flags & XFS_TRANS_SB_DIRTY)
		xfs_trans_apply_sb_deltas(tp);

With a modern lazysbcount filesystem, transactions update only the
percpu counters, so they don't need to set XFS_TRANS_SB_DIRTY, hence
xfs_trans_apply_sb_deltas is rarely called.

However, updates to the count of free realtime extents are not part of
lazysbcount, so XFS_TRANS_SB_DIRTY will be set on transactions adding or
removing data fork mappings to realtime files; similarly,
XFS_TRANS_SB_DIRTY is always set on !lazysbcount filesystems.

Dave mentioned in response to an earlier version of this patch:

"IIUC, what you are saying is that this debug code is simply not
exercised in normal testing and hasn't been for the past decade?  And it
still won't be exercised on anything other than realtime device testing?

"...it was debugging code from 1994 that was largely turned into dead
code when lazysbcounters were introduced in 2007. Hence I'm not sure it
holds any value anymore."

This debugging code isn't especially helpful - you can modify the
flcount on one AG and the freeblks of another AG, and it won't trigger.
Add the fact that nobody noticed for a decade, and let's just get rid of
it (and start testing realtime :P).

This bug was found by running generic/051 on either a V4 filesystem
lacking lazysbcount; or a V5 filesystem with a realtime volume.

Cc: bfoster@redhat.com, zlang@redhat.com
Fixes: f8f2835a ("xfs: defer agfl block frees when dfops is available")
Signed-off-by: NDarrick J. Wong <djwong@kernel.org>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Signed-off-by: NGuo Xuenan <guoxuenan@huawei.com>
Reviewed-by: NLihong Kou <koulihong@huawei.com>
Reviewed-by: NZhang Yi <yi.zhang@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

We should do the assert for all the log intent-done items if they appear
here. This patch detect intent-done items by the fact that their item ops
don't have iop_unpin and iop_push methods and also move the helper
xlog_item_is_intent to xfs_trans.h.
Signed-off-by: NKaixu Xia <kaixuxia@tencent.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Remove the mp argument as this function is only called in transaction
context, and open code xfs_getsb given that the function already accesses
the buffer pointer in the mount point directly.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Use kmem_cache_zalloc() directly.

With the exception of xlog_ticket_alloc() which will be dealt on the
next patch for readability.
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NCarlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

The rmapbt extent swap algorithm remaps individual extents between
the source inode and the target to trigger reverse mapping metadata
updates. If either inode straddles a format or other bmap allocation
boundary, the individual unmap and map cycles can trigger repeated
bmap block allocations and frees as the extent count bounces back
and forth across the boundary. While net block usage is bound across
the swap operation, this behavior can prematurely exhaust the
transaction block reservation because it continuously drains as the
transaction rolls. Each allocation accounts against the reservation
and each free returns to global free space on transaction roll.

The previous workaround to this problem attempted to detect this
boundary condition and provide surplus block reservation to
acommodate it. This is insufficient because more remaps can occur
than implied by the extent counts; if start offset boundaries are
not aligned between the two inodes, for example.

To address this problem more generically and dynamically, add a
transaction accounting mode that returns freed blocks to the
transaction reservation instead of the superblock counters on
transaction roll and use it when the rmapbt based algorithm is
active. This allows the chain of remap transactions to preserve the
block reservation based own its own frees and prevent premature
exhaustion regardless of the remap pattern. Note that this is only
safe for superblocks with lazy sb accounting, but the latter is
required for v5 supers and the rmap feature depends on v5.

Fixes: b3fed434 ("xfs: account format bouncing into rmapbt swapext tx reservation")
Root-caused-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

It's a global atomic counter, and we are hitting it at a rate of
half a million transactions a second, so it's bouncing the counter
cacheline all over the place on large machines. We don't actually
need it anymore - it used to be required because the VFS freeze code
could not track/prevent filesystem transactions that were running,
but that problem no longer exists.

Hence to remove the counter, we simply have to ensure that nothing
calls xfs_sync_sb() while we are trying to quiesce the filesytem.
That only happens if the log worker is still running when we call
xfs_quiesce_attr(). The log worker is cancelled at the end of
xfs_quiesce_attr() by calling xfs_log_quiesce(), so just call it
early here and then we can remove the counter altogether.

Concurrent create, 50 million inodes, identical 16p/16GB virtual
machines on different physical hosts. Machine A has twice the CPU
cores per socket of machine B:

		unpatched	patched
machine A:	3m16s		2m00s
machine B:	4m04s		4m05s

Create rates:
		unpatched	patched
machine A:	282k+/-31k	468k+/-21k
machine B:	231k+/-8k	233k+/-11k

Concurrent rm of same 50 million inodes:

		unpatched	patched
machine A:	6m42s		2m33s
machine B:	4m47s		4m47s

The transaction rate on the fast machine went from just under
300k/sec to 700k/sec, which indicates just how much of a bottleneck
this atomic counter was.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Shaokun Zhang reported that XFS was using substantial CPU time in
percpu_count_sum() when running a single threaded benchmark on
a high CPU count (128p) machine from xfs_mod_ifree(). The issue
is that the filesystem is empty when the benchmark runs, so inode
allocation is running with a very low inode free count.

With the percpu counter batching, this means comparisons when the
counter is less that 128 * 256 = 32768 use the slow path of adding
up all the counters across the CPUs, and this is expensive on high
CPU count machines.

The summing in xfs_mod_ifree() is only used to fire an assert if an
underrun occurs. The error is ignored by the higher level code.
Hence this is really just debug code and we don't need to run it
on production kernels, nor do we need such debug checks to return
error values just to trigger an assert.

Finally, xfs_mod_icount/xfs_mod_ifree are only called from
xfs_trans_unreserve_and_mod_sb(), so get rid of them and just
directly call the percpu_counter_add/percpu_counter_compare
functions. The compare functions are now run only on debug builds as
they are internal to ASSERT() checks and so only compiled in when
ASSERTs are active (CONFIG_XFS_DEBUG=y or CONFIG_XFS_WARN=y).
Reported-by: NShaokun Zhang <zhangshaokun@hisilicon.com>
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

xfs: gut error handling in xfs_trans_unreserve_and_mod_sb()

From: Dave Chinner <dchinner@redhat.com>

The error handling in xfs_trans_unreserve_and_mod_sb() is largely
incorrect - rolling back the changes in the transaction if only one
counter underruns makes all the other counters incorrect. We still
allow the change to proceed and committing the transaction, except
now we have multiple incorrect counters instead of a single
underflow.

Further, we don't actually report the error to the caller, so this
is completely silent except on debug kernels that will assert on
failure before we even get to the rollback code.  Hence this error
handling is broken, untested, and largely unnecessary complexity.

Just remove it.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Remove xlog_ticket_done and just call the renamed low-level helpers for
ungranting or regranting log space directly.  To make that a little
the reference put on the ticket and all tracing is moved into the actual
helpers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

xfs_log_done() does two separate things. Firstly, it triggers commit
records to be written for permanent transactions, and secondly it
releases or regrants transaction reservation space.

Since delayed logging was introduced, transactions no longer write
directly to the log, hence they never have the XLOG_TIC_INITED flag
cleared on them. Hence transactions never write commit records to
the log and only need to modify reservation space.

Split up xfs_log_done into two parts, and only call the parts of the
operation needed for the context xfs_log_done() is currently being
called from.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

I noticed that fsfreeze can take a very long time to freeze an XFS if
there happens to be a GETFSMAP caller running in the background.  I also
happened to notice the following in dmesg:

------------[ cut here ]------------
WARNING: CPU: 2 PID: 43492 at fs/xfs/xfs_super.c:853 xfs_quiesce_attr+0x83/0x90 [xfs]
Modules linked in: xfs libcrc32c ip6t_REJECT nf_reject_ipv6 ipt_REJECT nf_reject_ipv4 ip_set_hash_ip ip_set_hash_net xt_tcpudp xt_set ip_set_hash_mac ip_set nfnetlink ip6table_filter ip6_tables bfq iptable_filter sch_fq_codel ip_tables x_tables nfsv4 af_packet [last unloaded: xfs]
CPU: 2 PID: 43492 Comm: xfs_io Not tainted 5.6.0-rc4-djw #rc4
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
RIP: 0010:xfs_quiesce_attr+0x83/0x90 [xfs]
Code: 7c 07 00 00 85 c0 75 22 48 89 df 5b e9 96 c1 00 00 48 c7 c6 b0 2d 38 a0 48 89 df e8 57 64 ff ff 8b 83 7c 07 00 00 85 c0 74 de <0f> 0b 48 89 df 5b e9 72 c1 00 00 66 90 0f 1f 44 00 00 41 55 41 54
RSP: 0018:ffffc900030f3e28 EFLAGS: 00010202
RAX: 0000000000000001 RBX: ffff88802ac54000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff81e4a6f0 RDI: 00000000ffffffff
RBP: ffff88807859f070 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000010 R12: 0000000000000000
R13: ffff88807859f388 R14: ffff88807859f4b8 R15: ffff88807859f5e8
FS:  00007fad1c6c0fc0(0000) GS:ffff88807e000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0c7d237000 CR3: 0000000077f01003 CR4: 00000000001606a0
Call Trace:
 xfs_fs_freeze+0x25/0x40 [xfs]
 freeze_super+0xc8/0x180
 do_vfs_ioctl+0x70b/0x750
 ? __fget_files+0x135/0x210
 ksys_ioctl+0x3a/0xb0
 __x64_sys_ioctl+0x16/0x20
 do_syscall_64+0x50/0x1a0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

These two things appear to be related.  The assertion trips when another
thread initiates a fsmap request (which uses an empty transaction) after
the freezer waited for m_active_trans to hit zero but before the the
freezer executes the WARN_ON just prior to calling xfs_log_quiesce.

The lengthy delays in freezing happen because the freezer calls
xfs_wait_buftarg to clean out the buffer lru list.  Meanwhile, the
GETFSMAP caller is continuing to grab and release buffers, which means
that it can take a very long time for the buffer lru list to empty out.

We fix both of these races by calling sb_start_write to obtain freeze
protection while using empty transactions for GETFSMAP and for metadata
scrubbing.  The other two users occur during mount, during which time we
cannot fs freeze.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NDave Chinner <dchinner@redhat.com>

Just dereference bp->b_addr directly and make the code a little
simpler and more clear.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

We can remove it now, without needing to rework the KM_ flags.

Use kmem_cache_free() directly.
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NCarlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Since no caller is using KM_NOSLEEP and no callee branches on KM_SLEEP,
we can remove KM_NOSLEEP and replace KM_SLEEP with 0.
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Instead of a magic flag for xfs_trans_alloc, just ensure all callers
that can't relclaim through the file system use memalloc_nofs_save to
set the per-task nofs flag.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

There are many, many xfs header files which are included but
unneeded (or included twice) in the xfs code, so remove them.

nb: xfs_linux.h includes about 9 headers for everyone, so those
explicit includes get removed by this.  I'm not sure what the
preference is, but if we wanted explicit includes everywhere,
a followup patch could remove those xfs_*.h includes from
xfs_linux.h and move them into the files that need them.
Or it could be left as-is.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

We have various items that are released from ->iop_comitting.  Add a
flag to just call ->iop_release from the commit path to avoid tons
of boilerplate code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The iop_unlock method is called when comitting or cancelling a
transaction.  In the latter case, the transaction may or may not be
aborted.  While there is no known problem with the current code in
practice, this implementation is limited in that any log item
implementation that might want to differentiate between a commit and a
cancellation must rely on the aborted state.  The aborted bit is only
set when the cancelled transaction is dirty, however.  This means that
there is no way to distinguish between a commit and a clean transaction
cancellation.

For example, intent log items currently rely on this distinction.  The
log item is either transferred to the CIL on commit or released on
transaction cancel. There is currently no possibility for a clean intent
log item in a transaction, but if that state is ever introduced a cancel
of such a transaction will immediately result in memory leaks of the
associated log item(s).  This is an interface deficiency and landmine.

To clean this up, replace the iop_unlock method with an iop_release
method that is specific to transaction cancel.  The existing
iop_committing method occurs at the same time as iop_unlock in the
commit path and there is no need for two separate callbacks here.
Overload the iop_committing method with the current commit time
iop_unlock implementations to eliminate the need for the latter and
further simplify the interface.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

While commiting items looks very similar to freeing them on error it is
a different operation, and they will diverge a bit soon.

Split out the commit case from xfs_trans_free_items, inline it into
xfs_log_commit_cil and give it a separate trace point.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Just check if they are present first.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Just pass a straight bool aborted instead of abusing XFS_LI_ABORTED as a
flag in function parameters.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The flags value is always passed as 0 so remove the argument.
Signed-off-by: NEric Sandeen <sandeen@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

We've had a few reports of lockdep tripping over memory reclaim
context vs filesystem freeze "deadlocks". They all have looked
to be false positives on analysis, but it seems that they are
being tripped because we take freeze references before we run
a GFP_KERNEL allocation for the struct xfs_trans.

We can avoid this false positive vector just by re-ordering the
operations in xfs_trans_alloc(). That is. we need allocate the
structure before we take the freeze reference and enter the GFP_NOFS
allocation context that follows the xfs_trans around. This prevents
lockdep from seeing the GFP_KERNEL allocation inside the transaction
context, and that prevents it from triggering the freeze level vs
alloc context vs reclaim warnings.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

struct xfs_defer_ops has now been reduced to a single list_head. The
external dfops mechanism is unused and thus everywhere a (permanent)
transaction is accessible the associated dfops structure is as well.

Remove the xfs_defer_ops structure and fold the list_head into the
transaction. Also remove the last remnant of external dfops in
xfs_trans_dup().
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The xfs_defer_ops ->dop_pending list is used to track active
deferred operations once intents are logged. These items must be
aborted in the event of an error. The list is populated as intents
are logged and items are removed as they complete (or are aborted).

Now that xfs_defer_finish() cancels on error, there is no need to
ever access ->dop_pending outside of xfs_defer_finish(). The list is
only ever populated after xfs_defer_finish() begins and is either
completed or cancelled before it returns.

Remove ->dop_pending from xfs_defer_ops and replace it with a local
list in the xfs_defer_finish() path. Pass the local list to the
various helpers now that it is not accessible via dfops. Note that
we have to check for NULL in the abort case as the final tx roll
occurs outside of the scope of the new local list (once the dfops
has completed and thus drained the list).
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The current semantics of xfs_defer_finish() require the caller to
call xfs_defer_cancel() on error. This is slightly inconsistent with
transaction commit error handling where a failed commit cleans up
the transaction before returning.

More significantly, the only requirement for exposure of
->dop_pending outside of xfs_defer_finish() is so that
xfs_defer_cancel() can drain it on error. Since the only recourse of
xfs_defer_finish() errors is cancellation, mirror the transaction
logic and cancel remaining dfops before returning from
xfs_defer_finish() with an error.

Beside simplifying xfs_defer_finish() semantics, this ensures that
xfs_defer_finish() always returns with an empty ->dop_pending and
thus facilitates removal of the list from xfs_defer_ops.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The dfops code still passes around the xfs_defer_ops pointer
superfluously in a few places. Clean this up wherever the
transaction will suffice.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

All callers pass ->t_dfops of the associated transactions. Refactor
the helpers to receive the transactions and facilitate further
cleanups between xfs_defer_ops and xfs_trans.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

With no more external dfops users, there is no need for an
xfs_defer_ops cancel wrapper.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The current transaction allocation code conditionally initializes
the ->t_dfops indirection pointer. Transaction commit/cancel check
the validity of the pointer to determine whether to finish/cancel
the internal dfops.

This disallows the ability to use the internal dfops list as a
temporary container (via xfs_trans_alloc_empty()). Refactor
transaction allocation to always initialize ->t_dfops and check
permanent reservation state on transaction commit/cancel.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Once xfs_defer_finish() has completed all deferred operations, it
checks the dirty state of the transaction and rolls it once more to
return a clean transaction for the caller. This primarily to cover
the case where repeated xfs_defer_finish() calls are made in a loop
and we need to make sure that the caller starts the next iteration
with a clean transaction. Otherwise we risk transaction reservation
overrun.

This final transaction roll is not required in the transaction
commit path, however, because the transaction is immediately
committed and freed after dfops completion. Refactor the final roll
into a separate helper such that we can avoid it in the transaction
commit path.  Lift the dfops reset as well so dfops remains valid
until after the last call to xfs_defer_trans_roll(). The reset is
also unnecessary in the transaction commit path because the
transaction is about to complete.

This eliminates unnecessary regrants of transactions where the
associated transaction roll can be replaced by a transaction commit.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NBill O'Donnell <billodo@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

Every caller of xfs_defer_finish() now passes the transaction and
its associated ->t_dfops. The xfs_defer_ops parameter is therefore
no longer necessary and can be removed.

Since most xfs_defer_finish() callers also have to consider
xfs_defer_cancel() on error, update the latter to also receive the
transaction for consistency. The log recovery code contains an
outlier case that cancels a dfops directly without an available
transaction. Retain an internal wrapper to support this outlier case
for the time being.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NBill O'Donnell <billodo@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The dfops structure used by multi-transaction operations is
typically stored on the stack and carried around by the associated
transaction. The lifecycle of dfops does not quite match that of the
transaction, but they are tightly related in that the former depends
on the latter.

The relationship of these objects is tight enough that we can avoid
the cumbersome boilerplate code required in most cases to manage
them separately by just embedding an xfs_defer_ops in the
transaction itself. This means that a transaction allocation returns
with an initialized dfops, a transaction commit finishes pending
deferred items before the tx commit, a transaction cancel cancels
the dfops before the transaction and a transaction dup operation
transfers the current dfops state to the new transaction.

The dup operation is slightly complicated by the fact that we can no
longer just copy a dfops pointer from the old transaction to the new
transaction. This is solved through a dfops move helper that
transfers the pending items and other dfops state across the
transactions. This also requires that transaction rolling code
always refer to the transaction for the current dfops reference.

Finally, to facilitate incremental conversion to the internal dfops
and continue to support the current external dfops mode of
operation, create the new ->t_dfops_internal field with a layer of
indirection. On allocation, ->t_dfops points to the internal dfops.
This state is overridden by callers who re-init a local dfops on the
transaction. Once ->t_dfops is overridden, the external dfops
reference is maintained as the transaction rolls.

This patch adds the fundamental ability to support an internal
dfops. All codepaths that perform deferred processing continue to
override the internal dfops until they are converted over in
subsequent patches.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NBill O'Donnell <billodo@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

A firstblock var is typically allocated and initialized along with
xfs_defer_ops structures and passed around independent from the
associated transaction. To facilitate combining the two, add an
optional ->t_firstblock field to xfs_trans that can be used in place
of an on-stack variable.

The firstblock value follows the lifetime of the transaction, so
initialize it on allocation and when a transaction rolls.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

The ->t_agfl_dfops field is currently used to defer agfl block frees
from associated transaction contexts. While all known problematic
contexts have already been updated to use ->t_agfl_dfops, the
broader goal is defer agfl frees from all callers that already use a
deferred operations structure. Further, the transaction field
facilitates a good amount of code clean up where the transaction and
dfops have historically been passed down through the stack
separately.

Rename the field to something more generic to prepare to use it as
such throughout XFS. This patch does not change behavior.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>

In commit e89c0413 ("xfs: implement the GETFSMAP ioctl") we
created the ability to obtain empty transactions.  These transactions
have no log or block reservations and therefore can't modify anything.
Since they're also NO_WRITECOUNT they can run while the fs is frozen,
so we don't need to WARN_ON about that usage.
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NAllison Henderson <allison.henderson@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>

Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up-to-date license files in LICENSES/

This change was mostly scripted. fs/xfs/Makefile and
fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected
and modified by the following command:

for f in `git grep -l "GNU General" fs/xfs/` ; do
	echo $f
	cat $f | awk -f hdr.awk > $f.new
	mv -f $f.new $f
done

And the hdr.awk script that did the modification (including
detecting the difference between GPL-2.0 and GPL-2.0+ licenses)
is as follows:

$ cat hdr.awk
BEGIN {
	hdr = 1.0
	tag = "GPL-2.0"
	str = ""
}

/^ \* This program is free software/ {
	hdr = 2.0;
	next
}

/any later version./ {
	tag = "GPL-2.0+"
	next
}

/^ \*\// {
	if (hdr > 0.0) {
		print "// SPDX-License-Identifier: " tag
		print str
		print $0
		str=""
		hdr = 0.0
		next
	}
	print $0
	next
}

/^ \* / {
	if (hdr > 1.0)
		next
	if (hdr > 0.0) {
		if (str != "")
			str = str "\n"
		str = str $0
		next
	}
	print $0
	next
}

/^ \*/ {
	if (hdr > 0.0)
		next
	print $0
	next
}

// {
	if (hdr > 0.0) {
		if (str != "")
			str = str "\n"
		str = str $0
		next
	}
	print $0
}

END { }
$
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>