Commit Graph

210 Commits

Author SHA1 Message Date
Dave Chinner 3148ebf2c0 xfs: validity check agbnos on the AGFL
If the agfl or the indexing in the AGF has been corrupted, getting a
block form the AGFL could return an invalid block number. If this
happens, bad things happen. Check the agbno we pull off the AGFL
and return -EFSCORRUPTED if we find somethign bad.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2023-06-05 14:48:15 +10:00
Dave Chinner e0a8de7da3 xfs: fix agf/agfl verification on v4 filesystems
When a v4 filesystem has fl_last - fl_first != fl_count, we do not
not detect the corruption and allow the AGF to be used as it if was
fully valid. On V5 filesystems, we reset the AGFL to empty in these
cases and avoid the corruption at a small cost of leaked blocks.

If we don't catch the corruption on V4 filesystems, bad things
happen later when an allocation attempts to trim the free list
and either double-frees stale entries in the AGFl or tries to free
NULLAGBNO entries.

Either way, this is bad. Prevent this from happening by using the
AGFL_NEED_RESET logic for v4 filesysetms, too.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2023-06-05 14:48:15 +10:00
Dave Chinner 00dcd17cfa xfs: restore allocation trylock iteration
It was accidentally dropped when refactoring the allocation code,
resulting in the AG iteration always doing blocking AG iteration.
This results in a small performance regression for a specific fsmark
test that runs more user data writer threads than there are AGs.

Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: 2edf06a50f ("xfs: factor xfs_alloc_vextent_this_ag() for _iterate_ags()")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2023-06-05 04:06:27 +10:00
Darrick J. Wong 4a200a0978 xfs: implement masked btree key comparisons for _has_records scans
For keyspace fullness scans, we want to be able to mask off the parts of
the key that we don't care about.  For most btree types we /do/ want the
full keyspace, but for checking that a given space usage also has a full
complement of rmapbt records (even if different/multiple owners) we need
this masking so that we only track sparseness of rm_startblock, not the
whole keyspace (which is extremely sparse).

Augment the ->diff_two_keys and ->keys_contiguous helpers to take a
third union xfs_btree_key argument, and wire up xfs_rmap_has_records to
pass this through.  This third "mask" argument should contain a nonzero
value in each structure field that should be used in the key comparisons
done during the scan.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:11 -07:00
Darrick J. Wong 6abc7aef85 xfs: replace xfs_btree_has_record with a general keyspace scanner
The current implementation of xfs_btree_has_record returns true if it
finds /any/ record within the given range.  Unfortunately, that's not
sufficient for scrub.  We want to be able to tell if a range of keyspace
for a btree is devoid of records, is totally mapped to records, or is
somewhere in between.  By forcing this to be a boolean, we conflated
sparseness and fullness, which caused scrub to return incorrect results.
Fix the API so that we can tell the caller which of those three is the
current state.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:10 -07:00
Darrick J. Wong ee12eaaa43 xfs: complain about bad records in query_range helpers
For every btree type except for the bmbt, refactor the code that
complains about bad records into a helper and make the ->query_range
helpers call it so that corruptions found via that avenue are logged.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:04 -07:00
Darrick J. Wong 35e3b9a117 xfs: standardize ondisk to incore conversion for free space btrees
Create a xfs_alloc_btrec_to_irec function to convert an ondisk record to
an incore record, and a xfs_alloc_check_irec function to detect
corruption.  Replace all the open-coded logic with calls to the new
helpers and bubble up corruption reports.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-04-11 19:00:01 -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 4dfb02d5ca xfs: fix mismerged tracepoints
At some point in between sending this patch to the list and merging it
into for-next, the tracepoints got all mixed up because I've
over-reliant on automated tools not sucking.  The end result is that the
tracepoints are all wrong, so fix them.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2023-03-24 13:16:01 -07:00
Darrick J. Wong e2e63b071b xfs: clear incore AGFL_RESET state if it's not needed
Prior to commit 7ac2ff8bb3, when we loaded the incore perag structure
with information from the AGF header, we would set or clear the
pagf_agfl_reset field based on whether or not the AGFL list was
misaligned within the block.  IOWs, it's an incore state bit that's
supposed to cache something in the ondisk metadata.  Therefore, the code
still needs to support clearing the incore bit if (somehow) the AGFL
were to correct itself.

It turns out that xfs_repair does exactly this -- phase 4 loads the AGF
to scan the rmapbt for corrupt records, which can set NEEDS_AGFL_RESET.
The scan unsets AGF_INIT but doesn't unset NEEDS_AGFL_RESET.  Phase 5
totally rewrites the AGFL and fixes the alignment problem, didn't clear
NEEDS_AGFL_RESET historically, and reloads the perag state to fix the
freelist.  This results in the AGFL being reset based on stale data,
which then causes the new AGFL blocks to be leaked.  A subsequent
xfs_repair -n then complains about the leaks.

One could argue that phase 5 ought to clear this bit directly when it
reloads the perag AGF data after rewriting the AGFL, but libxfs used to
handle this for us, so it should go back to doing that.

Found by fuzzing flfirst = ones in xfs/352.

Fixes: 7ac2ff8bb3 ("xfs: perags need atomic operational state")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2023-03-24 08:40:02 -07:00
Darrick J. Wong e6fbb7167e xfs: add tracepoints for each of the externally visible allocators
There are now five separate space allocator interfaces exposed to the
rest of XFS for five different strategies to find space.  Add
tracepoints for each of them so that I can tell from a trace dump
exactly which ones got called and what happened underneath them.  Add a
sixth so it's more obvious if an allocation actually happened.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-03-19 09:55:49 -07:00
Darrick J. Wong 9eb775968b xfs: walk all AGs if TRYLOCK passed to xfs_alloc_vextent_iterate_ags
Callers of xfs_alloc_vextent_iterate_ags that pass in the TRYLOCK flag
want us to perform a non-blocking scan of the AGs for free space.  There
are no ordering constraints for non-blocking AGF lock acquisition, so
the scan can freely start over at AG 0 even when minimum_agno > 0.

This manifests fairly reliably on xfs/294 on 6.3-rc2 with the parent
pointer patchset applied and the realtime volume enabled.  I observed
the following sequence as part of an xfs_dir_createname call:

0. Fragment the free space, then allocate nearly all the free space in
   all AGs except AG 0.

1. Create a directory in AG 2 and let it grow for a while.

2. Try to allocate 2 blocks to expand the dirent part of a directory.
   The space will be allocated out of AG 0, but the allocation will not
   be contiguous.  This (I think) activates the LOWMODE allocator.

3. The bmapi call decides to convert from extents to bmbt format and
   tries to allocate 1 block.  This allocation request calls
   xfs_alloc_vextent_start_ag with the inode number, which starts the
   scan at AG 2.  We ignore AG 0 (with all its free space) and instead
   scrape AG 2 and 3 for more space.  We find one block, but this now
   kicks t_highest_agno to 3.

4. The createname call decides it needs to split the dabtree.  It tries
   to allocate even more space with xfs_alloc_vextent_start_ag, but now
   we're constrained to AG 3, and we don't find the space.  The
   createname returns ENOSPC and the filesystem shuts down.

This change fixes the problem by making the trylock scan wrap around to
AG 0 if it doesn't like the AGs that it finds.  Since the current
transaction itself holds AGF 0, the trylock of AGF 0 will succeed, and
we take space from the AG that has plenty.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-03-19 09:55:48 -07:00
Darrick J. Wong 6de4b1ab47 xfs: try to idiot-proof the allocators
In porting his development branch to 6.3-rc1, yours truly has
repeatedly screwed up the args->pag being fed to the xfs_alloc_vextent*
functions.  Add some debugging assertions to test the preconditions
required of the callers.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2023-03-16 09:32:18 -07:00
Dave Chinner 3432ef6111 xfs: convert xfs_alloc_vextent_iterate_ags() to use perag walker
Now that the AG iteration code in the core allocation code has been
cleaned up, we can easily convert it to use a for_each_perag..()
variant to use active references and skip AGs that it can't get
active references on.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:54 +11:00
Dave Chinner 8b81356825 xfs: move the minimum agno checks into xfs_alloc_vextent_check_args
All of the allocation functions now extract the minimum allowed AG
from the transaction and then use it in some way. The allocation
functions that are restricted to a single AG all check if the
AG requested can be allocated from and return an error if so. These
all set args->agno appropriately.

All the allocation functions that iterate AGs use it to calculate
the scan start AG. args->agno is not set until the iterator starts
walking AGs.

Hence we can easily set up a conditional check against the minimum
AG allowed in xfs_alloc_vextent_check_args() based on whether
args->agno contains NULLAGNUMBER or not and move all the repeated
setup code to xfs_alloc_vextent_check_args(), further simplifying
the allocation functions.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:54 +11:00
Dave Chinner 230e8fe846 xfs: fold xfs_alloc_ag_vextent() into callers
We don't need the multiplexing xfs_alloc_ag_vextent() provided
anymore - we can just call the exact/near/size variants directly.
This allows us to remove args->type completely and stop using
args->fsbno as an input to the allocator algorithms.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:54 +11:00
Dave Chinner e4d1742607 xfs: move allocation accounting to xfs_alloc_vextent_set_fsbno()
Move it from xfs_alloc_ag_vextent() so we can get rid of that layer.
Rename xfs_alloc_vextent_set_fsbno() to xfs_alloc_vextent_finish()
to indicate that it's function is finishing off the allocation that
we've run now that it contains much more functionality.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:54 +11:00
Dave Chinner 74b9aa6319 xfs: introduce xfs_alloc_vextent_prepare()
Now that we have wrapper functions for each type of allocation we
can ask for, we can start unravelling xfs_alloc_ag_vextent(). That
is essentially just a prepare stage, the allocation multiplexer
and a post-allocation accounting step is the allocation proceeded.

The current xfs_alloc_vextent*() wrappers all have a prepare stage,
the allocation operation and a post-allocation accounting step.

We can consolidate this by moving the AG alloc prep code into the
wrapper functions, the accounting code in the wrapper accounting
functions, and cut out the multiplexer layer entirely.

This patch consolidates the AG preparation stage.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:54 +11:00
Dave Chinner 5f36b2ce79 xfs: introduce xfs_alloc_vextent_exact_bno()
Two of the callers to xfs_alloc_vextent_this_ag() actually want
exact block number allocation, not anywhere-in-ag allocation. Split
this out from _this_ag() as a first class citizen so no external
extent allocation code needs to care about args->type anymore.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:54 +11:00
Dave Chinner db4710fd12 xfs: introduce xfs_alloc_vextent_near_bno()
The remaining callers of xfs_alloc_vextent() are all doing NEAR_BNO
allocations. We can replace that function with a new
xfs_alloc_vextent_near_bno() function that does this explicitly.

We also multiplex NEAR_BNO allocations through
xfs_alloc_vextent_this_ag via args->type. Replace all of these with
direct calls to xfs_alloc_vextent_near_bno(), too.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:54 +11:00
Dave Chinner 2a7f6d41d8 xfs: use xfs_alloc_vextent_start_bno() where appropriate
Change obvious callers of single AG allocation to use
xfs_alloc_vextent_start_bno(). Callers no long need to specify
XFS_ALLOCTYPE_START_BNO, and so the type can be driven inward and
removed.

While doing this, also pass the allocation target fsb as a parameter
rather than encoding it in args->fsbno.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:53 +11:00
Dave Chinner 319c9e874a xfs: use xfs_alloc_vextent_first_ag() where appropriate
Change obvious callers of single AG allocation to use
xfs_alloc_vextent_first_ag(). This gets rid of
XFS_ALLOCTYPE_FIRST_AG as the type used within
xfs_alloc_vextent_first_ag() during iteration is _THIS_AG. Hence we
can remove the setting of args->type from all the callers of
_first_ag() and remove the alloctype.

While doing this, pass the allocation target fsb as a parameter
rather than encoding it in args->fsbno. This starts the process
of making args->fsbno an output only variable rather than
input/output.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:53 +11:00
Dave Chinner 74c36a8689 xfs: use xfs_alloc_vextent_this_ag() where appropriate
Change obvious callers of single AG allocation to use
xfs_alloc_vextent_this_ag(). Drive the per-ag grabbing out to the
callers, too, so that callers with active references don't need
to do new lookups just for an allocation in a context that already
has a perag reference.

The only remaining caller that does single AG allocation through
xfs_alloc_vextent() is xfs_bmap_btalloc() with
XFS_ALLOCTYPE_NEAR_BNO. That is going to need more untangling before
it can be converted cleanly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:53 +11:00
Dave Chinner 4811c933ea xfs: combine __xfs_alloc_vextent_this_ag and xfs_alloc_ag_vextent
There's a bit of a recursive conundrum around
xfs_alloc_ag_vextent(). We can't first call xfs_alloc_ag_vextent()
without preparing the AGFL for the allocation, and preparing the
AGFL calls xfs_alloc_ag_vextent() to prepare the AGFL for the
allocation. This "double allocation" requirement is not really clear
from the current xfs_alloc_fix_freelist() calls that are sprinkled
through the allocation code.

It's not helped that xfs_alloc_ag_vextent() can actually allocate
from the AGFL itself, but there's special code to prevent AGFL prep
allocations from allocating from the free list it's trying to prep.
The naming is also not consistent: args->wasfromfl is true when we
allocated _from_ the free list, but the indication that we are
allocating _for_ the free list is via checking that (args->resv ==
XFS_AG_RESV_AGFL).

So, lets make this "allocation required for allocation" situation
clear by moving it all inside xfs_alloc_ag_vextent(). The freelist
allocation is a specific XFS_ALLOCTYPE_THIS_AG allocation, which
translated directly to xfs_alloc_ag_vextent_size() allocation.

This enables us to replace __xfs_alloc_vextent_this_ag() with a call
to xfs_alloc_ag_vextent(), and we drive the freelist fixing further
into the per-ag allocation algorithm.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:53 +11:00
Dave Chinner 2edf06a50f xfs: factor xfs_alloc_vextent_this_ag() for _iterate_ags()
The core of the per-ag iteration is effectively doing a "this ag"
allocation on one AG at a time. Use the same code to implement the
core "this ag" allocation in both xfs_alloc_vextent_this_ag()
and xfs_alloc_vextent_iterate_ags().

This means we only call xfs_alloc_ag_vextent() from one place so we
can easily collapse the call stack in future patches.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:53 +11:00
Dave Chinner ecd788a924 xfs: rework xfs_alloc_vextent()
It's a multiplexing mess that can be greatly simplified, and really
needs to be simplified to allow active per-ag references to
propagate from initial AG selection code the the bmapi code.

This splits the code out into separate a parameter checking
function, an iterator function, and allocation completion functions
and then implements the individual policies using these functions.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:53 +11:00
Dave Chinner 7ac2ff8bb3 xfs: perags need atomic operational state
We currently don't have any flags or operational state in the
xfs_perag except for the pagf_init and pagi_init flags. And the
agflreset flag. Oh, there's also the pagf_metadata and pagi_inodeok
flags, too.

For controlling per-ag operations, we are going to need some atomic
state flags. Hence add an opstate field similar to what we already
have in the mount and log, and convert all these state flags across
to atomic bit operations.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-13 09:14:52 +11:00
Dave Chinner 692b6cddeb xfs: t_firstblock is tracking AGs not blocks
The tp->t_firstblock field is now raelly tracking the highest AG we
have locked, not the block number of the highest allocation we've
made. It's purpose is to prevent AGF locking deadlocks, so rename it
to "highest AG" and simplify the implementation to just track the
agno rather than a fsbno.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-11 04:11:06 +11:00
Dave Chinner 1dd0510f6d xfs: fix low space alloc deadlock
I've recently encountered an ABBA deadlock with g/476. The upcoming
changes seem to make this much easier to hit, but the underlying
problem is a pre-existing one.

Essentially, if we select an AG for allocation, then lock the AGF
and then fail to allocate for some reason (e.g. minimum length
requirements cannot be satisfied), then we drop out of the
allocation with the AGF still locked.

The caller then modifies the allocation constraints - usually
loosening them up - and tries again. This can result in trying to
access AGFs that are lower than the AGF we already have locked from
the failed attempt. e.g. the failed attempt skipped several AGs
before failing, so we have locks an AG higher than the start AG.
Retrying the allocation from the start AG then causes us to violate
AGF lock ordering and this can lead to deadlocks.

The deadlock exists even if allocation succeeds - we can do a
followup allocations in the same transaction for BMBT blocks that
aren't guaranteed to be in the same AG as the original, and can move
into higher AGs. Hence we really need to move the tp->t_firstblock
tracking down into xfs_alloc_vextent() where it can be set when we
exit with a locked AG.

xfs_alloc_vextent() can also check there if the requested
allocation falls within the allow range of AGs set by
tp->t_firstblock. If we can't allocate within the range set, we have
to fail the allocation. If we are allowed to to non-blocking AGF
locking, we can ignore the AG locking order limitations as we can
use try-locks for the first iteration over requested AG range.

This invalidates a set of post allocation asserts that check that
the allocation is always above tp->t_firstblock if it is set.
Because we can use try-locks to avoid the deadlock in some
circumstances, having a pre-existing locked AGF doesn't always
prevent allocation from lower order AGFs. Hence those ASSERTs need
to be removed.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2023-02-11 04:07:06 +11:00
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
Jason A. Donenfeld 8032bf1233 treewide: use get_random_u32_below() instead of deprecated function
This is a simple mechanical transformation done by:

@@
expression E;
@@
- prandom_u32_max
+ get_random_u32_below
  (E)

Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Reviewed-by: SeongJae Park <sj@kernel.org> # for damon
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> # for infiniband
Reviewed-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> # for arm
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-11-18 02:15:15 +01:00
Darrick J. Wong b65e08f83b xfs: create a predicate to verify per-AG extents
Create a predicate function to verify that a given agbno/blockcount pair
fit entirely within a single allocation group and don't suffer
mathematical overflows.  Refactor the existng open-coded logic; we're
going to add more calls to this function in the next patch.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-10-31 08:58:20 -07:00
Jason A. Donenfeld 81895a65ec treewide: use prandom_u32_max() when possible, part 1
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:

@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)

@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@

-       RAND = get_random_u32();
        ... when != RAND
-       RAND %= (E);
+       RAND = prandom_u32_max(E);

// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@

        ((T)get_random_u32()@p & (LITERAL))

// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@

value = None
if literal.startswith('0x'):
        value = int(literal, 16)
elif literal[0] in '123456789':
        value = int(literal, 10)
if value is None:
        print("I don't know how to handle %s" % (literal))
        cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
        print("Skipping 0x%x for cleanup elsewhere" % (value))
        cocci.include_match(False)
elif value & (value + 1) != 0:
        print("Skipping 0x%x because it's not a power of two minus one" % (value))
        cocci.include_match(False)
elif literal.startswith('0x'):
        coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
        coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))

// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@

-       (FUNC()@p & (LITERAL))
+       prandom_u32_max(RESULT)

@collapse_ret@
type T;
identifier VAR;
expression E;
@@

 {
-       T VAR;
-       VAR = (E);
-       return VAR;
+       return E;
 }

@drop_var@
type T;
identifier VAR;
@@

 {
-       T VAR;
        ... when != VAR
 }

Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2022-10-11 17:42:55 -06:00
Slark Xiao 4869b6e84a xfs: Fix typo 'the the' in comment
Replace 'the the' with 'the' in the comment.

Signed-off-by: Slark Xiao <slark_xiao@163.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-07-22 10:58:39 -07:00
Dave Chinner 0800169e3e xfs: Pre-calculate per-AG agbno geometry
There is a lot of overhead in functions like xfs_verify_agbno() that
repeatedly calculate the geometry limits of an AG. These can be
pre-calculated as they are static and the verification context has
a per-ag context it can quickly reference.

In the case of xfs_verify_agbno(), we now always have a perag
context handy, so we can store the AG length and the minimum valid
block in the AG in the perag. This means we don't have to calculate
it on every call and it can be inlined in callers if we move it
to xfs_ag.h.

Move xfs_ag_block_count() to xfs_ag.c because it's really a
per-ag function and not an XFS type function. We need a little
bit of rework that is specific to xfs_initialise_perag() to allow
growfs to calculate the new perag sizes before we've updated the
primary superblock during the grow (chicken/egg situation).

Note that we leave the original xfs_verify_agbno in place in
xfs_types.c as a static function as other callers in that file do
not have per-ag contexts so still need to go the long way. It's been
renamed to xfs_verify_agno_agbno() to indicate it takes both an agno
and an agbno to differentiate it from new function.

Future commits will make similar changes for other per-ag geometry
validation functions.

Further:

$ size --totals fs/xfs/built-in.a
	   text    data     bss     dec     hex filename
before	1483006	 329588	    572	1813166	 1baaae	(TOTALS)
after	1482185	 329588	    572	1812345	 1ba779	(TOTALS)

This rework reduces the binary size by ~820 bytes, indicating
that much less work is being done to bounds check the agbno values
against on per-ag geometry information.

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 19:13:02 +10:00
Dave Chinner cec7bb7d58 xfs: pass perag to xfs_alloc_read_agfl
We have the perag in most places we call xfs_alloc_read_agfl, so
pass the perag instead of a mount/agno pair.

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 19:08:15 +10:00
Dave Chinner 8c392eb27f xfs: pass perag to xfs_alloc_put_freelist
It's available in all callers, so pass it in so that the perag can
be passed further down the stack.

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 19:08:08 +10:00
Dave Chinner 49f0d84ec1 xfs: pass perag to xfs_alloc_get_freelist
It's available in all callers, so pass it in so that the perag can
be passed further down the stack.

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 19:08:01 +10:00
Dave Chinner fa044ae70c xfs: pass perag to xfs_read_agf
We have the perag in most places we call xfs_read_agf, so pass the
perag instead of a mount/agno pair.

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 19:07:54 +10:00
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 76b47e528e xfs: kill xfs_alloc_pagf_init()
Trivial wrapper around xfs_alloc_read_agf(), can be easily replaced
by passing a NULL agfbp to xfs_alloc_read_agf().

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 19:07:32 +10:00
Dave Chinner a44a027a8b Merge tag 'large-extent-counters-v9' of https://github.com/chandanr/linux into xfs-5.19-for-next
xfs: Large extent counters

The commit xfs: fix inode fork extent count overflow
(3f8a4f1d87) mentions that 10 billion
data fork extents should be possible to create. However the
corresponding on-disk field has a signed 32-bit type. Hence this
patchset extends the per-inode data fork extent counter to 64 bits
(out of which 48 bits are used to store the extent count).

Also, XFS has an attribute fork extent counter which is 16 bits
wide. A workload that,
1. Creates 1 million 255-byte sized xattrs,
2. Deletes 50% of these xattrs in an alternating manner,
3. Tries to insert 400,000 new 255-byte sized xattrs
   causes the xattr extent counter to overflow.

Dave tells me that there are instances where a single file has more
than 100 million hardlinks. With parent pointers being stored in
xattrs, we will overflow the signed 16-bits wide attribute extent
counter when large number of hardlinks are created. Hence this
patchset extends the on-disk field to 32-bits.

The following changes are made to accomplish this,
1. A 64-bit inode field is carved out of existing di_pad and
   di_flushiter fields to hold the 64-bit data fork extent counter.
2. The existing 32-bit inode data fork extent counter will be used to
   hold the attribute fork extent counter.
3. A new incompat superblock flag to prevent older kernels from mounting
   the filesystem.

Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-21 16:46:17 +10:00
Dave Chinner f53dde11b4 xfs: convert AGF log flags to unsigned.
5.18 w/ std=gnu11 compiled with gcc-5 wants flags stored in unsigned
fields to be unsigned.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2022-04-21 10:46:16 +10:00
Chandan Babu R 95f0b95e2b xfs: Define max extent length based on on-disk format definition
The maximum extent length depends on maximum block count that can be stored in
a BMBT record. Hence this commit defines MAXEXTLEN based on
BMBT_BLOCKCOUNT_BITLEN.

While at it, the commit also renames MAXEXTLEN to XFS_MAX_BMBT_EXTLEN.

Suggested-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
2022-04-11 04:11:17 +00:00
Darrick J. Wong 93defd5a15 xfs: document the XFS_ALLOC_AGFL_RESERVE constant
Currently, we use this undocumented macro to encode the minimum number
of blocks needed to replenish a completely empty AGFL when an AG is
nearly full.  This has lead to confusion on the part of the maintainers,
so let's document what the value actually means, and move it to
xfs_alloc.c since it's not used outside of that module.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-03-21 13:57:45 -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
Darrick J. Wong 182696fb02 xfs: rename _zone variables to _cache
Now that we've gotten rid of the kmem_zone_t typedef, rename the
variables to _cache since that's what they are.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
2021-10-22 16:04:20 -07:00
Darrick J. Wong e7720afad0 xfs: remove kmem_zone typedef
Remove these typedefs by referencing kmem_cache directly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chandan Babu R <chandan.babu@oracle.com>
2021-10-22 16:00:31 -07:00