The way that tree mod log tracks the ultimate length of the eb, the
variable 'n', eventually turns up the correct value, but at intermediate
steps during the rewind, n can be inaccurate as a representation of the
end of the eb. For example, it doesn't get updated on move rewinds, and
it does get updated for add/remove in the middle of the eb.
To detect cases with invalid moves, introduce a separate variable called
max_slot which tries to track the maximum valid slot in the rewind eb.
We can then warn if we do a move whose src range goes beyond the max
valid slot.
There is a commented caveat that it is possible to have this value be an
overestimate due to the challenge of properly handling 'add' operations
in the middle of the eb, but in practice it doesn't cause enough of a
problem to throw out the max idea in favor of tracking every valid slot.
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Boris Burkov <boris@bur.io>
Signed-off-by: David Sterba <dsterba@suse.com>
The workspaces for compression are typically much larger than a page and
for high zstd levels in the range of megabytes. There's a fallback to
vmalloc but this can still fail (see the report).
Some of the workspaces are preallocated at module load time so we have a
safe fallback, otherwise when a new workspace is needed it's allocated
but if this fails then the process waits. Which means the warning is
only causing noise and we can use the GFP flag to disable it.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=217466
Signed-off-by: David Sterba <dsterba@suse.com>
need_full_stripe is just a somewhat complicated way to say
"op != BTRFS_MAP_READ". Just spell that explicit check out, which makes
a lot of the code currently using the helper easier to understand.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_map_sblock just hard codes three arguments and calls
btrfs_map_sblock. Remove it as it doesn't provide any real value, but
makes following the btrfs_map_block call chains harder.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that the old btrfs_map_block is gone, drop the leading underscores
from __btrfs_map_block.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are no users of btrfs_map_block left, so remove it.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Pass a smap into __btrfs_map_block so that the usual case of a read that
doesn't require parity raid recovery doesn't need an extra memory
allocation for the btrfs_io_context.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
BTRFS_MAP_DISCARD is never set, as REQ_OP_DISCARD is never passed to
btrfs_op() only only checked in two ASSERTS.
Remove it and let the catchall WARN_ON in btrfs_op() deal with accidental
REQ_OP_DISCARDs leaked into btrfs_op(). Last use was in a4012f06f1
("btrfs: split discard handling out of btrfs_map_block").
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The implementation of XXHASH is now CPU only but still fast enough to be
considered for the synchronous checksumming, like non-generic crc32c.
A userspace benchmark comparing it to various implementations (patched
hash-speedtest from btrfs-progs):
Block size: 4096
Iterations: 1000000
Implementation: builtin
Units: CPU cycles
NULL-NOP: cycles: 73384294, cycles/i 73
NULL-MEMCPY: cycles: 228033868, cycles/i 228, 61664.320 MiB/s
CRC32C-ref: cycles: 24758559416, cycles/i 24758, 567.950 MiB/s
CRC32C-NI: cycles: 1194350470, cycles/i 1194, 11773.433 MiB/s
CRC32C-ADLERSW: cycles: 6150186216, cycles/i 6150, 2286.372 MiB/s
CRC32C-ADLERHW: cycles: 626979180, cycles/i 626, 22427.453 MiB/s
CRC32C-PCL: cycles: 466746732, cycles/i 466, 30126.699 MiB/s
XXHASH: cycles: 860656400, cycles/i 860, 16338.188 MiB/s
Comparing purely software implementation (ref), current outdated
accelerated using crc32q instruction (NI), optimized implementations by
M. Adler (https://stackoverflow.com/questions/17645167/implementing-sse-4-2s-crc32c-in-software/17646775#17646775)
and the best one that was taken from kernel using the PCLMULQDQ
instruction (PCL).
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
split_extent_map splits off the first chunk of an extent map into a new
one. One of the two users is the zoned I/O completion code that wants to
rewrite the logical block start address right after this split. Pass in
the logical address to be set in the split off first extent_map as an
argument to avoid an extra extent tree lookup for this case.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
The btrfs zoned completion code currently needs an ordered_extent and
extent_map per bio so that it can account for the non-predictable
write location from Zone Append. To archive that it currently splits
the ordered_extent and extent_map at I/O submission time, and then
records the actual physical address in the ->physical field of the
ordered_extent.
This patch instead switches to record the "original" physical address
that the btrfs allocator assigned in spare space in the btrfs_bio,
and then rewrites the logical address in the btrfs_ordered_sum
structure at I/O completion time. This allows the ordered extent
completion handler to simply walk the list of ordered csums and
split the ordered extent as needed. This removes an extra ordered
extent and extent_map lookup and manipulation during the I/O
submission path, and instead batches it in the I/O completion path
where we need to touch these anyway.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
To delay splitting ordered_extents to I/O completion time we need to be
able to handle fully completed ordered extents in
btrfs_split_ordered_extent. Besides a bit of accounting this primarily
involved moving over the csums to the split bio for the range that it
covers, which is simple enough because we always have one
btrfs_ordered_sum per bio.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently there is a small race window in btrfs_split_ordered_extent,
where the reduced old extent can be looked up on the per-inode rbtree
or the per-root list while the newly split out one isn't visible yet.
Fix this by open coding btrfs_alloc_ordered_extent in
btrfs_split_ordered_extent, and holding the tree lock and
root->ordered_extent_lock over the entire tree and extent manipulation.
Note that this introduces new lock ordering because previously
ordered_extent_lock was never held over the tree lock.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Split two low-level helpers out of btrfs_alloc_ordered_extent to allocate
and insert the logic extent. The pure alloc helper will be used to
improve btrfs_split_ordered_extent.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Return the ordered_extent split from the passed in one. This will be
needed to be able to store an ordered_extent in the btrfs_bio.
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There is no good reason for doing one before the other in terms of
failure implications, but doing the extent_map split first will
simplify some upcoming refactoring.
Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
split_extent_map doesn't have anything to do with the other code in
inode.c, so move it to extent_map.c.
This also allows marking replace_extent_mapping static.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_submit_dev_bio is also called for clone bios that aren't embedded
into a btrfs_bio structure, but previous commit "btrfs: optimize the
logical to physical mapping for zoned writes" added code to assign
btrfs_bio.orig_physical in it.
This is harmless right now as only the single data profile can be used
on zoned devices, but will blow up when the RAID stripe tree is added.
Move it out into the single I/O specific branch in the caller.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
The current code to store the final logical to physical mapping for a
zone append write in the extent tree is rather inefficient. It first has
to split the ordered extent so that there is one ordered extent per bio,
so that it can look up the ordered extent on I/O completion in
btrfs_record_physical_zoned and store the physical LBA returned by the
block driver in the ordered extent.
btrfs_rewrite_logical_zoned then has to do a lookup in the chunk tree to
see what physical address the logical address for this bio / ordered
extent is mapped to, and then rewrite it in the extent tree.
To optimize this process, we can store the physical address assigned in
the chunk tree to the original logical address and a pointer to
btrfs_ordered_sum structure the in the btrfs_bio structure, and then use
this information to rewrite the logical address in the btrfs_ordered_sum
structure directly at I/O completion time in btrfs_record_physical_zoned.
btrfs_rewrite_logical_zoned then simply updates the logical address in
the extent tree and the ordered_extent itself.
The code in btrfs_rewrite_logical_zoned now runs for all data I/O
completions in zoned file systems, which is fine as there is no remapping
to do for non-append writes to conventional zones or for relocation, and
the overhead for quickly breaking out of the loop is very low.
Because zoned file systems now need the ordered_sums structure to
record the actual write location returned by zone append, allocate dummy
structures without the csum array for them when the I/O doesn't use
checksums, and free them when completing the ordered_extent.
Note that the btrfs_bio doesn't grow as the new field are places into
a union that is so far not used for data writes and has plenty of space
left in it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_ordered_sum::bytendr stores a logical address. Make that clear by
renaming it to ->logical.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
len can't ever be negative, so mark it as an u32 instead of int.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When a zoned append command fails there is no written address reported,
so don't try to record it.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add an IS_ENABLED check for CONFIG_BLK_DEV_ZONED in addition to the
run-time check for the zone size. This will allow to make use of
compiler dead code elimination for code guarded by btrfs_is_zoned, and
for example provide just a dangling prototype for a function instead of
adding a stub.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_destroy_delayed_refs() always returns 0 and its single caller does
not check its return value, as it also returns void, and so does the
callers' caller and so on. This is because we are in the transaction abort
path, where we have no way to deal with errors (we are in a critical
situation) and all cleanup of resources works in a best effort fashion.
So make btrfs_destroy_delayed_refs() return void.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We have a few static functions at disk-io.c for which we have a forward
declaration of their prototype, but it's not needed because all those
functions are defined before they are called, so remove them.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At init_delayed_ref_head(), we are using two separate if statements to
check the delayed ref head action, and initializing 'must_insert_reserved'
to false twice, once when the variable is declared and once again in an
else branch.
Make this simpler and more straightforward by having a single switch
statement, also moving the comment about a drop action to the
corresponding switch case to make it more clear and eliminating the
duplicated initialization of 'must_insert_reserved' to false.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There's no point in have several fields defined as 1 bit unsigned int in
struct btrfs_delayed_ref_head, we can instead use a bool type, it makes
the code a bit more readable and it doesn't change the structure size.
So switch them to proper booleans.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The function btrfs_select_ref_head() iterates over the red black tree of
delayed reference heads, which is protected by the spinlock in the delayed
refs root. The function doesn't take the lock, it's taken by its single
caller, btrfs_obtain_ref_head(), because it needs to call that function
and btrfs_delayed_ref_lock() in the same critical section (delimited by
that spinlock). So assert at btrfs_select_ref_head() that we are holding
the expected lock.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At insert_delayed_ref() there's no point of having a label and goto in the
case we were able to insert the delayed ref head. We can just add the code
under label to the if statement's body and return immediately, and also
there is no need to track the return value in a variable, we can just
return a literal true or false value directly. So do those changes.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
insert_delayed_ref() can only return 0 or 1, to indicate if the given
delayed reference was added to the head reference or if it was merged
into an existing delayed ref, respectively. So just make it return a
boolean instead.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
We are using an integer as a boolean to track the qgroup record insertion
status when adding a delayed reference head. Since all we need is a
boolean, switch the type from int to bool to make it more obvious.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The 'in_tree' field is really not needed in struct btrfs_delayed_ref_node,
as we can check whether a reference is in the tree or not simply by
checking its red black tree node member with RB_EMPTY_NODE(), as when we
remove it from the tree we always call RB_CLEAR_NODE(). So remove that
field and use RB_EMPTY_NODE().
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The 'is_head' field of struct btrfs_delayed_ref_node is no longer after
commit d278850eff ("btrfs: remove delayed_ref_node from ref_head"),
so remove it.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In function end_bio_extent_readpage() we call
endio_readpage_release_extent() to unlock the extent io tree.
However we pass PageUptodate(page) as @uptodate parameter for it, while
for previous end_page_read() call, we use a dedicated @uptodate local
variable.
This is not a big deal, as even for subpage cases, either the bio only
covers part of the page, then the @uptodate is always false, and the
subpage ranges can still be merged.
But for the sake of consistency, always use @uptodate variable when
possible.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently alloc_extent_buffer() would make the extent buffer uptodate if
the corresponding pages are also uptodate.
But this check is only checking PageUptodate, which is fine for regular
cases, but not for subpage cases, as we can have multiple extent buffers
in the same page.
So here we go btrfs_page_test_uptodate() instead.
The old code doesn't cause any problem, but is not efficient, as it
would cause extra metadata read even if the range is already uptodate.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Assertions reports are split into two parts, the exact file and location
of the condition and then the stack trace printed from
btrfs_assertfail(). This means all the stack traces report the same line
and this is what's typically reported by various tools, making it harder
to distinguish the reports.
[403.2467] assertion failed: refcount_read(&block_group->refs) == 1, in fs/btrfs/block-group.c:4259
[403.2479] ------------[ cut here ]------------
[403.2484] kernel BUG at fs/btrfs/messages.c:259!
[403.2488] invalid opcode: 0000 [#1] PREEMPT SMP KASAN
[403.2493] CPU: 2 PID: 23202 Comm: umount Not tainted 6.2.0-rc4-default+ #67
[403.2499] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552-rebuilt.opensuse.org 04/01/2014
[403.2509] RIP: 0010:btrfs_assertfail+0x19/0x1b [btrfs]
...
[403.2595] Call Trace:
[403.2598] <TASK>
[403.2601] btrfs_free_block_groups.cold+0x52/0xae [btrfs]
[403.2608] close_ctree+0x6c2/0x761 [btrfs]
[403.2613] ? __wait_for_common+0x2b8/0x360
[403.2618] ? btrfs_cleanup_one_transaction.cold+0x7a/0x7a [btrfs]
[403.2626] ? mark_held_locks+0x6b/0x90
[403.2630] ? lockdep_hardirqs_on_prepare+0x13d/0x200
[403.2636] ? __call_rcu_common.constprop.0+0x1ea/0x3d0
[403.2642] ? trace_hardirqs_on+0x2d/0x110
[403.2646] ? __call_rcu_common.constprop.0+0x1ea/0x3d0
[403.2652] generic_shutdown_super+0xb0/0x1c0
[403.2657] kill_anon_super+0x1e/0x40
[403.2662] btrfs_kill_super+0x25/0x30 [btrfs]
[403.2668] deactivate_locked_super+0x4c/0xc0
By making btrfs_assertfail a macro we'll get the same line number for
the BUG output:
[63.5736] assertion failed: 0, in fs/btrfs/super.c:1572
[63.5758] ------------[ cut here ]------------
[63.5782] kernel BUG at fs/btrfs/super.c:1572!
[63.5807] invalid opcode: 0000 [#2] PREEMPT SMP KASAN
[63.5831] CPU: 0 PID: 859 Comm: mount Tainted: G D 6.3.0-rc7-default+ #2062
[63.5868] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a-rebuilt.opensuse.org 04/01/2014
[63.5905] RIP: 0010:btrfs_mount+0x24/0x30 [btrfs]
[63.5964] RSP: 0018:ffff88800e69fcd8 EFLAGS: 00010246
[63.5982] RAX: 000000000000002d RBX: ffff888008fc1400 RCX: 0000000000000000
[63.6004] RDX: 0000000000000000 RSI: ffffffffb90fd868 RDI: ffffffffbcc3ff20
[63.6026] RBP: ffffffffc081b200 R08: 0000000000000001 R09: ffff88800e69fa27
[63.6046] R10: ffffed1001cd3f44 R11: 0000000000000001 R12: ffff888005a3c370
[63.6062] R13: ffffffffc058e830 R14: 0000000000000000 R15: 00000000ffffffff
[63.6081] FS: 00007f7b3561f800(0000) GS:ffff88806c600000(0000) knlGS:0000000000000000
[63.6105] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[63.6120] CR2: 00007fff83726e10 CR3: 0000000002a9e000 CR4: 00000000000006b0
[63.6137] Call Trace:
[63.6143] <TASK>
[63.6148] legacy_get_tree+0x80/0xd0
[63.6158] vfs_get_tree+0x43/0x120
[63.6166] do_new_mount+0x1f3/0x3d0
[63.6176] ? do_add_mount+0x140/0x140
[63.6187] ? cap_capable+0xa4/0xe0
[63.6197] path_mount+0x223/0xc10
This comes at a cost of bloating the final btrfs.ko module due all the
inlining, as long as assertions are compiled in. This is a must for
debugging builds but this is often enabled on release builds too.
Release build:
text data bss dec hex filename
1251676 20317 16088 1288081 13a791 pre/btrfs.ko
1260612 29473 16088 1306173 13ee3d post/btrfs.ko
DELTA: +8936
CC: Josh Poimboeuf <jpoimboe@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
There is a bug report that assert_eb_page_uptodate() gets triggered for
free space tree metadata.
Without proper dump for the subpage bitmaps it's much harder to debug.
Thus this patch would dump all the subpage bitmaps (split them into
their own bitmaps) for a easier debugging.
The output would look like this:
(Dumped after a tree block got read from disk)
page:000000006e34bf49 refcount:4 mapcount:0 mapping:0000000067661ac4 index:0x1d1 pfn:0x110e9
memcg:ffff0000d7d62000
aops:btree_aops [btrfs] ino:1
flags: 0x8000000000002002(referenced|private|zone=2)
page_type: 0xffffffff()
raw: 8000000000002002 0000000000000000 dead000000000122 ffff00000188bed0
raw: 00000000000001d1 ffff0000c7992700 00000004ffffffff ffff0000d7d62000
page dumped because: btrfs subpage dump
BTRFS warning (device dm-1): start=30490624 len=16384 page=30474240 bitmaps: uptodate=4-7 error= dirty= writeback= ordered= checked=
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
BACKGROUND
==========
When multiple work items are queued to a workqueue, their execution order
doesn't match the queueing order. They may get executed in any order and
simultaneously. When fully serialized execution - one by one in the queueing
order - is needed, an ordered workqueue should be used which can be created
with alloc_ordered_workqueue().
However, alloc_ordered_workqueue() was a later addition. Before it, an
ordered workqueue could be obtained by creating an UNBOUND workqueue with
@max_active==1. This originally was an implementation side-effect which was
broken by 4c16bd327c ("workqueue: restore WQ_UNBOUND/max_active==1 to be
ordered"). Because there were users that depended on the ordered execution,
5c0338c687 ("workqueue: restore WQ_UNBOUND/max_active==1 to be ordered")
made workqueue allocation path to implicitly promote UNBOUND workqueues w/
@max_active==1 to ordered workqueues.
While this has worked okay, overloading the UNBOUND allocation interface
this way creates other issues. It's difficult to tell whether a given
workqueue actually needs to be ordered and users that legitimately want a
min concurrency level wq unexpectedly gets an ordered one instead. With
planned UNBOUND workqueue updates to improve execution locality and more
prevalence of chiplet designs which can benefit from such improvements, this
isn't a state we wanna be in forever.
This patch series audits all call sites that create an UNBOUND workqueue w/
@max_active==1 and converts them to alloc_ordered_workqueue() as necessary.
BTRFS
=====
* fs_info->scrub_workers initialized in scrub_workers_get() was setting
@max_active to 1 when @is_dev_replace is set and it seems that the
workqueue actually needs to be ordered if @is_dev_replace. Update the code
so that alloc_ordered_workqueue() is used if @is_dev_replace.
* fs_info->discard_ctl.discard_workers initialized in
btrfs_init_workqueues() was directly using alloc_workqueue() w/
@max_active==1. Converted to alloc_ordered_workqueue().
* fs_info->fixup_workers and fs_info->qgroup_rescan_workers initialized in
btrfs_queue_work() use the btrfs's workqueue wrapper, btrfs_workqueue,
which are allocated with btrfs_alloc_workqueue().
btrfs_workqueue implements automatic @max_active adjustment which is
disabled when the specified max limit is below a certain threshold, so
calling btrfs_alloc_workqueue() with @limit_active==1 yields an ordered
workqueue whose @max_active won't be changed as the auto-tuning is
disabled.
This is rather brittle in that nothing clearly indicates that the two
workqueues should be ordered or btrfs_alloc_workqueue() must disable
auto-tuning when @limit_active==1.
This patch factors out the common btrfs_workqueue init code into
btrfs_init_workqueue() and add explicit btrfs_alloc_ordered_workqueue().
The two workqueues are converted to use the new ordered allocation
interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: David Sterba <dsterba@suse.com>
Now that all extent state bit helpers effectively take the GFP_NOFS mask
(and GFP_NOWAIT is encoded in the bits) we can remove the parameter.
This reduces stack consumption in many functions and simplifies a lot of
code.
Net effect on module on a release build:
text data bss dec hex filename
1250432 20985 16088 1287505 13a551 pre/btrfs.ko
1247074 20985 16088 1284147 139833 post/btrfs.ko
DELTA: -3358
Signed-off-by: David Sterba <dsterba@suse.com>
The only flags we now pass to set_extent_bit/__clear_extent_bit are
GFP_NOFS and GFP_NOWAIT (a few functions handling mappings). This
requires an extra parameter to be passed everywhere but is almost always
the same.
Encode the GFP_NOWAIT as an artificial extent bit and extract the
real bits and gfp mask in the lowest level helpers. Now the passed
gfp mask is not actually used and can be removed.
Signed-off-by: David Sterba <dsterba@suse.com>
The __GFP_NOFAIL passed to set_extent_bit first appeared in 2010
(commit f0486c68e4 ("Btrfs: Introduce contexts for metadata
reservation")), without any explanation why it would be needed.
Meanwhile we've updated the semantics of set_extent_bit to handle failed
allocations and do unlock, sleep and retry if needed. The use of the
NOFAIL flag is also an outlier, we never want any of the set/clear
extent bit helpers to fail, they're used for many critical changes like
extent locking, besides the extent state bit changes.
Signed-off-by: David Sterba <dsterba@suse.com>
This helper calls set_extent_bit with two more parameters set to default
values, but otherwise it's purpose is not clear.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helper only passes GFP_NOWAIT as gfp flags and is used two times.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helper is used a few times, that it's setting the DIRTY extent bit
is still clear.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helper is used only once.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helper is used once in fs code and a few times in the self test
code.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The helper is used only once.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
btrfs_grab_root already checks for a NULL root itself.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use a switch statement instead of an endless chain of if statements
to make the code a little cleaner.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
