Commit Graph

147 Commits

Author SHA1 Message Date
Christoph Hellwig
e9c4d8bfb2 xfs: factor out a generic xfs_group structure
Split the lookup and refcount handling of struct xfs_perag into an
embedded xfs_group structure that can be reused for the upcoming
realtime groups.

It will be extended with more features later.

Note that he xg_type field will only need a single bit even with
realtime group support.  For now it fills a hole, but it might be
worth to fold it into another field if we can use this space better.

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>
2024-11-05 13:38:27 -08:00
Christoph Hellwig
db129fa011 xfs: remove the agno argument to xfs_free_ag_extent
xfs_free_ag_extent already has a pointer to the pag structure through
the agf buffer.  Use that instead of passing the redundant argument,
and do the same for the tracepoint.

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>
2024-11-05 13:38:24 -08:00
Darrick J. Wong
84a3c1576c xfs: move xfs_extent_free_defer_add to xfs_extfree_item.c
Move the code that adds the incore xfs_extent_free_item deferred work
data to a transaction to live with the EFI log item code.  This means
that the allocator code no longer has to know about the inner workings
of the EFI log items.

As a consequence, we can get rid of the _{get,put}_group helpers.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-07-02 11:37:03 -07:00
Christoph Hellwig
81927e6ec6 xfs: factor out a xfs_efd_add_extent helper
Factor out a helper to add an extent to and EFD instead of duplicating
the logic in two places.

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>
2024-07-02 11:37:02 -07:00
Christoph Hellwig
61665fae4e xfs: reuse xfs_extent_free_cancel_item
Reuse xfs_extent_free_cancel_item to put the AG/RTG and free the item in
a few places that currently open code the logic.

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>
2024-07-02 11:37:02 -07:00
Christoph Hellwig
649c0c2b86 xfs: add a xefi_entry helper
Add a helper to translate from the item list head to the
xfs_extent_free_item structure and use it so shorten assignments
and avoid the need for extra local variables.

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>
2024-07-02 11:37:01 -07:00
Christoph Hellwig
62d597a197 xfs: pass the fsbno to xfs_perag_intent_get
All callers of xfs_perag_intent_get have a fsbno and need boilerplate
code to turn that into an agno.  Just pass the fsbno to
xfs_perag_intent_get and look up the agno there.

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>
2024-07-02 11:37:01 -07:00
Darrick J. Wong
4e0e2c0fe3 xfs: clean up extent free log intent item tracepoint callsites
Pass the incore EFI structure to the tracepoints instead of open-coding
the argument passing.  This cleans up the call sites a bit.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2024-07-02 11:37:01 -07:00
Gao Xiang
d40c2865bd xfs: avoid redundant AGFL buffer invalidation
Currently AGFL blocks can be filled from the following three sources:
 - allocbt free blocks, as in xfs_allocbt_free_block();
 - rmapbt free blocks, as in xfs_rmapbt_free_block();
 - refilled from freespace btrees, as in xfs_alloc_fix_freelist().

Originally, allocbt free blocks would be marked as stale only when they
put back in the general free space pool as Dave mentioned on IRC, "we
don't stale AGF metadata btree blocks when they are returned to the
AGFL .. but once they get put back in the general free space pool, we
have to make sure the buffers are marked stale as the next user of
those blocks might be user data...."

However, after commit ca250b1b3d ("xfs: invalidate allocbt blocks
moved to the free list") and commit edfd9dd549 ("xfs: move buffer
invalidation to xfs_btree_free_block"), even allocbt / bmapbt free
blocks will be invalidated immediately since they may fail to pass
V5 format validation on writeback even writeback to free space would be
safe.

IOWs, IMHO currently there is actually no difference of free blocks
between AGFL freespace pool and the general free space pool.  So let's
avoid extra redundant AGFL buffer invalidation, since otherwise we're
currently facing unnecessary xfs_log_force() due to xfs_trans_binval()
again on buffers already marked as stale before as below:

[  333.507469] Call Trace:
[  333.507862]  xfs_buf_find+0x371/0x6a0       <- xfs_buf_lock
[  333.508451]  xfs_buf_get_map+0x3f/0x230
[  333.509062]  xfs_trans_get_buf_map+0x11a/0x280
[  333.509751]  xfs_free_agfl_block+0xa1/0xd0
[  333.510403]  xfs_agfl_free_finish_item+0x16e/0x1d0
[  333.511157]  xfs_defer_finish_noroll+0x1ef/0x5c0
[  333.511871]  xfs_defer_finish+0xc/0xa0
[  333.512471]  xfs_itruncate_extents_flags+0x18a/0x5e0
[  333.513253]  xfs_inactive_truncate+0xb8/0x130
[  333.513930]  xfs_inactive+0x223/0x270

xfs_log_force() will take tens of milliseconds with AGF buffer locked.
It becomes an unnecessary long latency especially on our PMEM devices
with FSDAX enabled and fsops like xfs_reflink_find_shared() at the same
time are stuck due to the same AGF lock.  Removing the double
invalidation on the AGFL blocks does not make this issue go away, but
this patch fixes for our workloads in reality and it should also work
by the code analysis.

Note that I'm not sure I need to remove another redundant one in
xfs_alloc_ag_vextent_small() since it's unrelated to our workloads.
Also fstests are passed with this patch.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-07-01 09:32:29 +05:30
Dave Chinner
d4c75a1b40 xfs: convert remaining kmem_free() to kfree()
The remaining callers of kmem_free() are freeing heap memory, so
we can convert them directly to kfree() and get rid of kmem_free()
altogether.

This conversion was done with:

$ for f in `git grep -l kmem_free fs/xfs`; do
> sed -i s/kmem_free/kfree/ $f
> done
$

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13 18:07:34 +05:30
Dave Chinner
4929257613 xfs: convert kmem_free() for kvmalloc users to kvfree()
Start getting rid of kmem_free() by converting all the cases where
memory can come from vmalloc interfaces to calling kvfree()
directly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2024-02-13 18:07:34 +05:30
Christoph Hellwig
dc22af6436 xfs: pass the defer ops instead of type to xfs_defer_start_recovery
xfs_defer_start_recovery is only called from xlog_recover_intent_item,
and the callers of that all have the actual xfs_defer_ops_type operation
vector at hand.  Pass that directly instead of looking it up from the
defer_op_types table.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2023-12-14 11:13:38 +05:30
Christoph Hellwig
7f2f7531e0 xfs: store an ops pointer in struct xfs_defer_pending
The dfp_type field in struct xfs_defer_pending is only used to either
look up the operations associated with the pending word or in trace
points.  Replace it with a direct pointer to the operations vector,
and store a pretty name in the vector for tracing.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
2023-12-14 11:10:34 +05:30
Darrick J. Wong
e3042be36c xfs: automatic freeing of freshly allocated unwritten space
As mentioned in the previous commit, online repair wants to allocate
space to write out a new metadata structure, and it also wants to hedge
against system crashes during repairs by logging (and later cancelling)
EFIs to free the space if we crash before committing the new data
structure.

Therefore, create a trio of functions to schedule automatic reaping of
freshly allocated unwritten space.  xfs_alloc_schedule_autoreap creates
a paused EFI representing the space we just allocated.  Once the
allocations are made and the autoreaps scheduled, we can start writing
to disk.

If the writes succeed, xfs_alloc_cancel_autoreap marks the EFI work
items as stale and unpauses the pending deferred work item.  Assuming
that's done in the same transaction that commits the new structure into
the filesystem, we guarantee that either the new object is fully
visible, or that all the space gets reclaimed.

If the writes succeed but only part of an extent was used, repair must
call the same _cancel_autoreap function to kill the first EFI and then
log a new EFI to free the unused space.  The first EFI is already
committed, so it cannot be changed.

For full extents that aren't used, xfs_alloc_commit_autoreap will
unpause the EFI, which results in the space being freed during the next
_defer_finish cycle.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:18 -08:00
Darrick J. Wong
a49c708f9a xfs: move ->iop_relog to struct xfs_defer_op_type
The only log items that need relogging are the ones created for deferred
work operations, and the only part of the code base that relogs log
items is the deferred work machinery.  Move the function pointers.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:17 -08:00
Darrick J. Wong
8a9aa763e1 xfs: collapse the ->create_done functions
Move the meat of the ->create_done function helpers into ->create_done
to reduce the amount of boilerplate.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:16 -08:00
Darrick J. Wong
b28852a5bd xfs: hoist xfs_trans_add_item calls to defer ops functions
Remove even more repeated boilerplate.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:16 -08:00
Darrick J. Wong
3e0958be21 xfs: clean out XFS_LI_DIRTY setting boilerplate from ->iop_relog
Hoist this dirty flag setting to the ->iop_relog callsite to reduce
boilerplate.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:16 -08:00
Darrick J. Wong
bd3a88f6b7 xfs: use xfs_defer_create_done for the relogging operation
Now that we have a helper to handle creating a log intent done item and
updating all the necessary state flags, use it to reduce boilerplate in
the ->iop_relog implementations.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:16 -08:00
Darrick J. Wong
f3fd7f6fce xfs: hoist ->create_intent boilerplate to its callsite
Hoist the dirty flag setting code out of each ->create_intent
implementation up to the callsite to reduce boilerplate further.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:16 -08:00
Darrick J. Wong
e6e5299fcb xfs: collapse the ->finish_item helpers
Each log item's ->finish_item function sets up a small amount of state
and calls another function to do the work.  Collapse that other function
into ->finish_item to reduce the call stack height.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:16 -08:00
Darrick J. Wong
3dd75c8db1 xfs: hoist intent done flag setting to ->finish_item callsite
Each log intent item's ->finish_item call chain inevitably includes some
code to set the dirty flag of the transaction.  If there's an associated
log intent done item, it also sets the item's dirty flag and the
transaction's INTENT_DONE flag.  This is repeated throughout the
codebase.

Reduce the LOC by moving all that to xfs_defer_finish_one.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:15 -08:00
Darrick J. Wong
db7ccc0bac xfs: move ->iop_recover to xfs_defer_op_type
Finish off the series by moving the intent item recovery function
pointer to the xfs_defer_op_type struct, since this is really a deferred
work function now.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:15 -08:00
Darrick J. Wong
e5f1a5146e xfs: use xfs_defer_finish_one to finish recovered work items
Get rid of the open-coded calls to xfs_defer_finish_one.  This also
means that the recovery transaction takes care of cleaning up the dfp,
and we have solved (I hope) all the ownership issues in recovery.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:15 -08:00
Darrick J. Wong
e70fb328d5 xfs: recreate work items when recovering intent items
Recreate work items for each xfs_defer_pending object when we are
recovering intent items.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:15 -08:00
Darrick J. Wong
deb4cd8ba8 xfs: transfer recovered intent item ownership in ->iop_recover
Now that we pass the xfs_defer_pending object into the intent item
recovery functions, we know exactly when ownership of the sole refcount
passes from the recovery context to the intent done item.  At that
point, we need to null out dfp_intent so that the recovery mechanism
won't release it.  This should fix the UAF problem reported by Long Li.

Note that we still want to recreate the full deferred work state.  That
will be addressed in the next patches.

Fixes: 2e76f188fd ("xfs: cancel intents immediately if process_intents fails")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:14 -08:00
Darrick J. Wong
a050acdfa8 xfs: pass the xfs_defer_pending object to iop_recover
Now that log intent item recovery recreates the xfs_defer_pending state,
we should pass that into the ->iop_recover routines so that the intent
item can finish the recreation work.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:14 -08:00
Darrick J. Wong
03f7767c9f xfs: use xfs_defer_pending objects to recover intent items
One thing I never quite got around to doing is porting the log intent
item recovery code to reconstruct the deferred pending work state.  As a
result, each intent item open codes xfs_defer_finish_one in its recovery
method, because that's what the EFI code did before xfs_defer.c even
existed.

This is a gross thing to have left unfixed -- if an EFI cannot proceed
due to busy extents, we end up creating separate new EFIs for each
unfinished work item, which is a change in behavior from what runtime
would have done.

Worse yet, Long Li pointed out that there's a UAF in the recovery code.
The ->commit_pass2 function adds the intent item to the AIL and drops
the refcount.  The one remaining refcount is now owned by the recovery
mechanism (aka the log intent items in the AIL) with the intent of
giving the refcount to the intent done item in the ->iop_recover
function.

However, if something fails later in recovery, xlog_recover_finish will
walk the recovered intent items in the AIL and release them.  If the CIL
hasn't been pushed before that point (which is possible since we don't
force the log until later) then the intent done release will try to free
its associated intent, which has already been freed.

This patch starts to address this mess by having the ->commit_pass2
functions recreate the xfs_defer_pending state.  The next few patches
will fix the recovery functions.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2023-12-06 18:45:14 -08:00
Darrick J. Wong
3c919b0910 xfs: reserve less log space when recovering log intent items
Wengang Wang reports that a customer's system was running a number of
truncate operations on a filesystem with a very small log.  Contention
on the reserve heads lead to other threads stalling on smaller updates
(e.g.  mtime updates) long enough to result in the node being rebooted
on account of the lack of responsivenes.  The node failed to recover
because log recovery of an EFI became stuck waiting for a grant of
reserve space.  From Wengang's report:

"For the file deletion, log bytes are reserved basing on
xfs_mount->tr_itruncate which is:

    tr_logres = 175488,
    tr_logcount = 2,
    tr_logflags = XFS_TRANS_PERM_LOG_RES,

"You see it's a permanent log reservation with two log operations (two
transactions in rolling mode).  After calculation (xlog_calc_unit_res()
adds space for various log headers), the final log space needed per
transaction changes from  175488 to 180208 bytes.  So the total log
space needed is 360416 bytes (180208 * 2).  [That quantity] of log space
(360416 bytes) needs to be reserved for both run time inode removing
(xfs_inactive_truncate()) and EFI recover (xfs_efi_item_recover())."

In other words, runtime pre-reserves 360K of space in anticipation of
running a chain of two transactions in which each transaction gets a
180K reservation.

Now that we've allocated the transaction, we delete the bmap mapping,
log an EFI to free the space, and roll the transaction as part of
finishing the deferops chain.  Rolling creates a new xfs_trans which
shares its ticket with the old transaction.  Next, xfs_trans_roll calls
__xfs_trans_commit with regrant == true, which calls xlog_cil_commit
with the same regrant parameter.

xlog_cil_commit calls xfs_log_ticket_regrant, which decrements t_cnt and
subtracts t_curr_res from the reservation and write heads.

If the filesystem is fresh and the first transaction only used (say)
20K, then t_curr_res will be 160K, and we give that much reservation
back to the reservation head.  Or if the file is really fragmented and
the first transaction actually uses 170K, then t_curr_res will be 10K,
and that's what we give back to the reservation.

Having done that, we're now headed into the second transaction with an
EFI and 180K of reservation.  Other threads apparently consumed all the
reservation for smaller transactions, such as timestamp updates.

Now let's say the first transaction gets written to disk and we crash
without ever completing the second transaction.  Now we remount the fs,
log recovery finds the unfinished EFI, and calls xfs_efi_recover to
finish the EFI.  However, xfs_efi_recover starts a new tr_itruncate
tranasction, which asks for 360K log reservation.  This is a lot more
than the 180K that we had reserved at the time of the crash.  If the
first EFI to be recovered is also pinning the tail of the log, we will
be unable to free any space in the log, and recovery livelocks.

Wengang confirmed this:

"Now we have the second transaction which has 180208 log bytes reserved
too. The second transaction is supposed to process intents including
extent freeing.  With my hacking patch, I blocked the extent freeing 5
hours. So in that 5 hours, 180208 (NOT 360416) log bytes are reserved.

"With my test case, other transactions (update timestamps) then happen.
As my hacking patch pins the journal tail, those timestamp-updating
transactions finally use up (almost) all the left available log space
(in memory in on disk).  And finally the on disk (and in memory)
available log space goes down near to 180208 bytes.  Those 180208 bytes
are reserved by [the] second (extent-free) transaction [in the chain]."

Wengang and I noticed that EFI recovery starts a transaction, completes
one step of the chain, and commits the transaction without completing
any other steps of the chain.  Those subsequent steps are completed by
xlog_finish_defer_ops, which allocates yet another transaction to
finish the rest of the chain.  That transaction gets the same tr_logres
as the head transaction, but with tr_logcount = 1 to force regranting
with every roll to avoid livelocks.

In other words, we already figured this out in commit 929b92f640
("xfs: xfs_defer_capture should absorb remaining transaction
reservation"), but should have applied that logic to each intent item's
recovery function.  For Wengang's case, the xfs_trans_alloc call in the
EFI recovery function should only be asking for a single transaction's
worth of log reservation -- 180K, not 360K.

Quoting Wengang again:

"With log recovery, during EFI recovery, we use tr_itruncate again to
reserve two transactions that needs 360416 log bytes.  Reserving 360416
bytes fails [stalls] because we now only have about 180208 available.

"Actually during the EFI recover, we only need one transaction to free
the extents just like the 2nd transaction at RUNTIME.  So it only needs
to reserve 180208 rather than 360416 bytes.  We have (a bit) more than
180208 available log bytes on disk, so [if we decrease the reservation
to 180K] the reservation goes and the recovery [finishes].  That is to
say: we can fix the log recover part to fix the issue. We can introduce
a new xfs_trans_res xfs_mount->tr_ext_free

{
  tr_logres = 175488,
  tr_logcount = 0,
  tr_logflags = 0,
}

"and use tr_ext_free instead of tr_itruncate in EFI recover."

However, I don't think it quite makes sense to create an entirely new
transaction reservation type to handle single-stepping during log
recovery.  Instead, we should copy the transaction reservation
information in the xfs_mount, change tr_logcount to 1, and pass that
into xfs_trans_alloc.  We know this won't risk changing the min log size
computation since we always ask for a fraction of the reservation for
all known transaction types.

This looks like it's been lurking in the codebase since commit
3d3c8b5222, which changed the xfs_trans_reserve call in
xlog_recover_process_efi to use the tr_logcount in tr_itruncate.
That changed the EFI recovery transaction from making a
non-XFS_TRANS_PERM_LOG_RES request for one transaction's worth of log
space to a XFS_TRANS_PERM_LOG_RES request for two transactions worth.

Fixes: 3d3c8b5222 ("xfs: refactor xfs_trans_reserve() interface")
Complements: 929b92f640 ("xfs: xfs_defer_capture should absorb remaining transaction reservation")
Suggested-by: Wengang Wang <wen.gang.wang@oracle.com>
Cc: Srikanth C S <srikanth.c.s@oracle.com>
[djwong: apply the same transformation to all log intent recovery]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-09-12 10:31:07 -07:00
Yang Li
34acceaa88 xfs: Remove unneeded semicolon
./fs/xfs/xfs_extfree_item.c:723:3-4: Unneeded semicolon

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Closes: https://bugzilla.openanolis.cn/show_bug.cgi?id=5728
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2023-07-03 09:48:18 -07:00
Dave Chinner
0853b5de42 xfs: allow extent free intents to be retried
Extent freeing neeeds to be able to avoid a busy extent deadlock
when the transaction itself holds the only busy extents in the
allocation group. This may occur if we have an EFI that contains
multiple extents to be freed, and the freeing the second intent
requires the space the first extent free released to expand the
AGFL. If we block on the busy extent at this point, we deadlock.

We hold a dirty transaction that contains a entire atomic extent
free operations within it, so if we can abort the extent free
operation and commit the progress that we've made, the busy extent
can be resolved by a log force. Hence we can restart the aborted
extent free with a new transaction and continue to make
progress without risking deadlocks.

To enable this, we need the EFI processing code to be able to handle
an -EAGAIN error to tell it to commit the current transaction and
retry again. This mechanism is already built into the defer ops
processing (used bythe refcount btree modification intents), so
there's relatively little handling we need to add to the EFI code to
enable this.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
2023-06-29 09:28:24 -07:00
Dave Chinner
b742d7b4f0 xfs: use deferred frees for btree block freeing
Btrees that aren't freespace management trees use the normal extent
allocation and freeing routines for their blocks. Hence when a btree
block is freed, a direct call to xfs_free_extent() is made and the
extent is immediately freed. This puts the entire free space
management btrees under this path, so we are stacking btrees on
btrees in the call stack. The inobt, finobt and refcount btrees
all do this.

However, the bmap btree does not do this - it calls
xfs_free_extent_later() to defer the extent free operation via an
XEFI and hence it gets processed in deferred operation processing
during the commit of the primary transaction (i.e. via intent
chaining).

We need to change xfs_free_extent() to behave in a non-blocking
manner so that we can avoid deadlocks with busy extents near ENOSPC
in transactions that free multiple extents. Inserting or removing a
record from a btree can cause a multi-level tree merge operation and
that will free multiple blocks from the btree in a single
transaction. i.e. we can call xfs_free_extent() multiple times, and
hence the btree manipulation transaction is vulnerable to this busy
extent deadlock vector.

To fix this, convert all the remaining callers of xfs_free_extent()
to use xfs_free_extent_later() to queue XEFIs and hence defer
processing of the extent frees to a context that can be safely
restarted if a deadlock condition is detected.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
2023-06-29 09:28:23 -07:00
Darrick J. Wong
d5c88131db xfs: allow queued AG intents to drain before scrubbing
When a writer thread executes a chain of log intent items, the AG header
buffer locks will cycle during a transaction roll to get from one intent
item to the next in a chain.  Although scrub takes all AG header buffer
locks, this isn't sufficient to guard against scrub checking an AG while
that writer thread is in the middle of finishing a chain because there's
no higher level locking primitive guarding allocation groups.

When there's a collision, cross-referencing between data structures
(e.g. rmapbt and refcountbt) yields false corruption events; if repair
is running, this results in incorrect repairs, which is catastrophic.

Fix this by adding to the perag structure the count of active intents
and make scrub wait until it has both AG header buffer locks and the
intent counter reaches zero.

One quirk of the drain code is that deferred bmap updates also bump and
drop the intent counter.  A fundamental decision made during the design
phase of the reverse mapping feature is that updates to the rmapbt
records are always made by the same code that updates the primary
metadata.  In other words, callers of bmapi functions expect that the
bmapi functions will queue deferred rmap updates.

Some parts of the reflink code queue deferred refcount (CUI) and bmap
(BUI) updates in the same head transaction, but the deferred work
manager completely finishes the CUI before the BUI work is started.  As
a result, the CUI drops the intent count long before the deferred rmap
(RUI) update even has a chance to bump the intent count.  The only way
to keep the intent count elevated between the CUI and RUI is for the BUI
to bump the counter until the RUI has been created.

A second quirk of the intent drain code is that deferred work items must
increment the intent counter as soon as the work item is added to the
transaction.  When a BUI completes and queues an RUI, the RUI must
increment the counter before the BUI decrements it.  The only way to
accomplish this is to require that the counter be bumped as soon as the
deferred work item is created in memory.

In the next patches we'll improve on this facility, but this patch
provides the basic functionality.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:58 -07:00
Darrick J. Wong
f6b384631e xfs: give xfs_extfree_intent its own perag reference
Give the xfs_extfree_intent an passive reference to the perag structure
data.  This reference will be used to enable scrub intent draining
functionality in subsequent patches.  The space being freed must already
be allocated, so we need to able to run even if the AG is being offlined
or shrunk.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:54 -07:00
Darrick J. Wong
b2ccab3199 xfs: pass per-ag references to xfs_free_extent
Pass a reference to the per-AG structure to xfs_free_extent.  Most
callers already have one, so we can eliminate unnecessary lookups.  The
one exception to this is the EFI code, which the next patch will fix.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 18:59:53 -07:00
Darrick J. Wong
578c714b21 xfs: fix confusing xfs_extent_item variable names
Change the name of all pointers to xfs_extent_item structures to "xefi"
to make the name consistent and because the current selections ("new"
and "free") mean other things in C.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2023-02-05 08:48:11 -08:00
Darrick J. Wong
72ba455599 xfs: pass xfs_extent_free_item directly through the log intent code
Pass the incore xfs_extent_free_item through the EFI logging code
instead of repeatedly boxing and unboxing parameters.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2023-02-05 08:48:11 -08:00
Darrick J. Wong
950f0d50ee xfs: dump corrupt recovered log intent items to dmesg consistently
If log recovery decides that an intent item is corrupt and wants to
abort the mount, capture a hexdump of the corrupt log item in the kernel
log for further analysis.  Some of the log item code already did this,
so we're fixing the rest to do it consistently.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-10-31 08:58:20 -07:00
Darrick J. Wong
921ed96b4f xfs: actually abort log recovery on corrupt intent-done log items
If log recovery picks up intent-done log items that are not of the
correct size it needs to abort recovery and fail the mount.  Debug
assertions are not good enough.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-10-31 08:58:20 -07:00
Darrick J. Wong
3c5aaaced9 xfs: refactor all the EFI/EFD log item sizeof logic
Refactor all the open-coded sizeof logic for EFI/EFD log item and log
format structures into common helper functions whose names reflect the
struct names.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-10-31 08:58:20 -07:00
Darrick J. Wong
03a7485cd7 xfs: fix memcpy fortify errors in EFI log format copying
Starting in 6.1, CONFIG_FORTIFY_SOURCE checks the length parameter of
memcpy.  Since we're already fixing problems with BUI item copying, we
should fix it everything else.

An extra difficulty here is that the ef[id]_extents arrays are declared
as single-element arrays.  This is not the convention for flex arrays in
the modern kernel, and it causes all manner of problems with static
checking tools, since they often cannot tell the difference between a
single element array and a flex array.

So for starters, change those array[1] declarations to array[]
declarations to signal that they are proper flex arrays and adjust all
the "size-1" expressions to fit the new declaration style.

Next, refactor the xfs_efi_copy_format function to handle the copying of
the head and the flex array members separately.  While we're at it, fix
a minor validation deficiency in the recovery function.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-10-31 08:58:20 -07:00
Xie Shaowen
5e9466a5d0 xfs: delete extra space and tab in blank line
delete extra space and tab in blank line, there is no functional change.

Reported-by: Hacash Robot <hacashRobot@santino.com>
Signed-off-by: Xie Shaowen <studentxswpy@163.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-07-31 09:21:27 -07:00
Dave Chinner
08d3e84fee xfs: pass perag to xfs_alloc_read_agf()
xfs_alloc_read_agf() initialises the perag if it hasn't been done
yet, so it makes sense to pass it the perag rather than pull a
reference from the buffer. This allows callers to be per-ag centric
rather than passing mount/agno pairs everywhere.

Whilst modifying the xfs_reflink_find_shared() function definition,
declare it static and remove the extern declaration as it is an
internal function only these days.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-07 19:07:40 +10:00
Dave Chinner
3512fc1e84 xfs: whiteouts release intents that are not in the AIL
When we release an intent that a whiteout applies to, it will not
have been committed to the journal and so won't be in the AIL. Hence
when we drop the last reference to the intent, we do not want to try
to remove it from the AIL as that will trigger a filesystem
shutdown. Hence make the removal of intents from the AIL conditional
on them actually being in the AIL so we do the correct thing.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04 11:46:47 +10:00
Dave Chinner
c23ab603e3 xfs: add log item method to return related intents
To apply a whiteout to an intent item when an intent done item is
committed, we need to be able to retrieve the intent item from the
the intent done item. Add a log item op method for doing this, and
wire all the intent done items up to it.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04 11:46:39 +10:00
Dave Chinner
bb7b1c9c5d xfs: tag transactions that contain intent done items
Intent whiteouts will require extra work to be done during
transaction commit if the transaction contains an intent done item.

To determine if a transaction contains an intent done item, we want
to avoid having to walk all the items in the transaction to check if
they are intent done items. Hence when we add an intent done item to
a transaction, tag the transaction to indicate that it contains such
an item.

We don't tag the transaction when the defer ops is relogging an
intent to move it forward in the log. Whiteouts will never apply to
these cases, so we don't need to bother looking for them.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04 11:46:21 +10:00
Dave Chinner
f5b81200b6 xfs: add log item flags to indicate intents
We currently have a couple of helper functions that try to infer
whether the log item is an intent or intent done item from the
combinations of operations it supports.  This is incredibly fragile
and not very efficient as it requires checking specific combinations
of ops.

We need to be able to identify intent and intent done items quickly
and easily in upcoming patches, so simply add intent and intent done
type flags to the log item ops flags. These are static flags to
begin with, so intent items should have been typed like this from
the start.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-05-04 11:46:09 +10:00
Dave Chinner
d86142dd7c xfs: log items should have a xlog pointer, not a mount
Log items belong to the log, not the xfs_mount. Convert the mount
pointer in the log item to a xlog pointer in preparation for
upcoming log centric changes to the log items.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-03-20 08:59:49 -07:00
Darrick J. Wong
b3b5ff412a xfs: reduce the size of struct xfs_extent_free_item
We only use EFIs to free metadata blocks -- not regular data/attr fork
extents.  Remove all the fields that we never use, for a net reduction
of 16 bytes.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
2021-10-22 16:04:36 -07:00
Darrick J. Wong
c201d9ca53 xfs: rename xfs_bmap_add_free to xfs_free_extent_later
xfs_bmap_add_free isn't a block mapping function; it schedules deferred
freeing operations for a later point in a compound transaction chain.
While it's primarily used by bunmapi, its use has expanded beyond that.
Move it to xfs_alloc.c and rename the function since it's now general
freeing functionality.  Bring the slab cache bits in line with the
way we handle the other intent items.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
2021-10-22 16:04:36 -07:00