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Currently we set the type of a delayed item only after successfully
inserting it into its respective rbtree. This is fine, as the type
is not used anywhere before that point, but for the next patch in the
series, there will be the need to check the type of a delayed item
before inserting it into a rbtree.
So set the type of a delayed item immediately after allocating it.
This also makes the trivial wrappers for adding insertion and deletion
useless, so it removes them as well.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At btrfs_insert_delayed_dir_index(), we don't expect the metadata
reservation for the delayed dir index item insertion to fail, because the
caller is supposed to have reserved 1 unit of metadata space for that.
All callers are able to deal with an error in case that happens, so there
is no need for something so drastic as a BUG_ON() in case of failure.
Instead just emit a warning, so that's easily noticed during development
(fstests in particular), and return the error to the caller.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently we group delayed dir index items for insertion as a single batch
(a single btree operation) as long as their keys are sequential in the key
space.
For example we have delayed index items for the following index keys:
10, 11, 12, 15, 16, 20, 21
We end up building three batches:
1) First one for index keys 10, 11 and 12;
2) Second one for index keys 15 and 16;
3) Third one for index keys 20 and 21.
However, since the dir index numbers come from a monotonically increasing
counter and are never reused, we could group all these items into a single
batch. The existence of holes in the sequence happens only when we had
delayed dir index items for insertion that got deleted before they were
flushed to the subvolume's tree.
The delayed items are stored in a rbtree based on their key order, so
we can just group items into a batch as long as they all fit in a leaf,
and ignore if there's a gap (key offset, index number) between two
consecutive items. This is more efficient and reduces the amount of
time spent when running delayed items if there are gaps between dir
index items.
For example running the following test script:
$ cat test.sh
#!/bin/bash
DEV=/dev/sdj
MNT=/mnt/sdj
mkfs.btrfs -f $DEV
mount $DEV $MNT
NUM_FILES=100
mkdir $MNT/testdir
for ((i = 1; i <= $NUM_FILES; i++)); do
echo -n > $MNT/testdir/file_$i
done
# Now delete every other file, to create gaps in the dir index keys.
for ((i = 1; i <= $NUM_FILES; i += 2)); do
rm -f $MNT/testdir/file_$i
done
start=$(date +%s%N)
sync
end=$(date +%s%N)
dur=$(( (end - start) / 1000000 ))
echo -e "\nsync took $dur milliseconds"
umount $MNT
While having the following bpftrace script running in another shell:
$ cat bpf-delayed-items-inserts.sh
#!/usr/bin/bpftrace
/* Must add 'noinline' to btrfs_insert_delayed_items(). */
k:btrfs_insert_delayed_items
{
@start_insert_delayed_items[tid] = nsecs;
}
k:btrfs_insert_empty_items
/@start_insert_delayed_items[tid]/
{
@insert_batches = count();
}
kr:btrfs_insert_delayed_items
/@start_insert_delayed_items[tid]/
{
$dur = (nsecs - @start_insert_delayed_items[tid]) / 1000;
@btrfs_insert_delayed_items_total_time = sum($dur);
delete(@start_insert_delayed_items[tid]);
}
Before this change:
@btrfs_insert_delayed_items_total_time: 576
@insert_batches: 51
After this change:
@btrfs_insert_delayed_items_total_time: 174
@insert_batches: 2
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
All delayed items are for dir index items, we don't support any other item
types at the moment. So simplify __btrfs_add_delayed_item() and add an
assertion for checking the item's key type. This also allows the next
change to be simpler and avoid to check key types. In case we add support
for different item types in the future, then we'll hit the assertion
during development and be able to adjust any code that is assuming delayed
items are always associated to dir index items.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently we group delayed dir index items for deletion in a single batch
(single btree operation) as long as they all exist in the same leaf and as
long as their keys are sequential in the key space. For example if we have
a leaf that has dir index items with offsets:
2, 3, 4, 6, 7, 10
And we have delayed dir index items for deleting all these indexes, and
no delayed items for any other index keys in between, then we end up
deleting in 3 batches:
1) First batch for indexes 2, 3 and 4;
2) Second batch for indexes 6 and 7;
3) Third batch for index 10.
This is a waste because we can delete all the index keys in a single
batch. What matters is that each consecutive delayed index key matches
each consecutive dir index key in a leaf.
So update the logic at btrfs_batch_delete_items() to check only for a
key match between delayed dir index items and dir index items in a leaf.
Also avoid the useless first iteration on comparing the key of the
first slot to delete with the key of the first delayed item, as it's
silly since they always match, as the delayed item's key was used for
the btree search that gave us the path we have.
This is more efficient and reduces runtime of running delayed items, as
well as lock contention on the subvolume's tree.
For example, the following test script:
$ cat test.sh
#!/bin/bash
DEV=/dev/sdj
MNT=/mnt/sdj
mkfs.btrfs -f $DEV
mount $DEV $MNT
NUM_FILES=1000
mkdir $MNT/testdir
for ((i = 1; i <= $NUM_FILES; i++)); do
echo -n > $MNT/testdir/file_$i
done
# Now delete every other file, to create gaps in the dir index keys.
for ((i = 1; i <= $NUM_FILES; i += 2)); do
rm -f $MNT/testdir/file_$i
done
# Sync to force any delayed items to be flushed to the tree.
sync
start=$(date +%s%N)
rm -fr $MNT/testdir
end=$(date +%s%N)
dur=$(( (end - start) / 1000000 ))
echo -e "\nrm -fr took $dur milliseconds"
umount $MNT
Running that test script while having the following bpftrace script
running in another shell:
$ cat bpf-measure.sh
#!/usr/bin/bpftrace
/* Add 'noinline' to btrfs_delete_delayed_items()'s definition. */
k:btrfs_delete_delayed_items
{
@start_delete_delayed_items[tid] = nsecs;
}
k:btrfs_del_items
/@start_delete_delayed_items[tid]/
{
@delete_batches = count();
}
kr:btrfs_delete_delayed_items
/@start_delete_delayed_items[tid]/
{
$dur = (nsecs - @start_delete_delayed_items[tid]) / 1000;
@btrfs_delete_delayed_items_total_time = sum($dur);
delete(@start_delete_delayed_items[tid]);
}
Before this change:
@btrfs_delete_delayed_items_total_time: 9563
@delete_batches: 1001
After this change:
@btrfs_delete_delayed_items_total_time: 7328
@delete_batches: 509
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The delayed item deletion entry point, btrfs_delete_delayed_items(), is a
bit convoluted for a few reasons:
1) It's really a loop disguised with labels and goto statements;
2) There's a 'delete_fail' label which isn't only for error cases, we can
jump to that label even if no error happened, if we simply don't have
more delayed items to delete;
3) Unnecessarily keeps track of the current and previous items for no
good reason, as after getting the next item and releasing the current
one, it just jumps to the 'again' label just to look again for the
first delayed item;
4) When a delayed item is not in the tree (because it was already deleted
before), it releases the item while holding a path locked, which is
not necessary and adds more contention to the tree, specially taking
into account that the path came from a deletion search, meaning we have
write locks for nodes at levels 2, 1 and 0. And releasing the item is
not computationally trivial (rb tree deletion, a kfree() and some
trivial things).
So refactor it to use a while loop and add some comments to make it more
obvious why we can have delayed items without a matching item in the tree
as well as why not keep the delayed node locked all the time when running
all its deletion items. This is also a preparation for some upcoming work
involving delayed items.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently, btrfs_delete_delayed_items() ignores any errors returned from
btrfs_batch_delete_items(). This looks fishy but it's not a problem at
the moment because:
1) Two of the errors returned from btrfs_batch_delete_items() are for
impossible cases, cases where a delayed item does not match any item
in the leaf the path points to - btrfs_delete_delayed_items() always
calls btrfs_batch_delete_items() with a path that points to a leaf
that contains an item matching a delayed item;
2) btrfs_batch_delete_items() may return an error from btrfs_del_items(),
in which case it does not release the delayed items of the batch.
At the moment this is harmless because btrfs_del_items() actually is
always able to delete items, even if it returns an error - when it
returns an error it's because it ended up with a leaf mostly empty
(less than 1/3 full) and failed to migrate items from that leaf into
its neighbour leaves - this is not critical, as all the items were
deleted, we just left the tree a bit unbalanced, but it's still a
valid tree and causes no harm, and future operations on the tree will
eventually balance it.
So even if we get an error from btrfs_del_items(), the delayed items
will not be released but the next time we run delayed items we will
find out, at btrfs_delete_delayed_items(), that they are not present
in the tree anymore and then release them.
This is all a bit subtle, and it's certainly prone to be a disaster in
case btrfs_del_items() changes one day and may return errors before being
able to delete all the requested items, in which case we could leave the
filesystem in an inconsistent state as we would commit a transaction
despite a failure from deleting items from the tree.
So make btrfs_delete_delayed_items() check for any errors from the call
to btrfs_batch_delete_items().
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
There are a few impossible cases that btrfs_batch_delete_items() tries to
deal with:
1) Getting a path pointing to a NULL leaf;
2) The leaf slot is pointing beyond the last item in the leaf;
3) We can't find a single item to delete.
The first case is impossible because the given path was returned by a
successful call to btrfs_search_slot(). Replace the BUG_ON() with an
ASSERT for this.
The second case is impossible because we are always called when a delayed
item matches an item in the given leaf. So add an ASSERT() for that and
if that condition is not satisfied, trigger a warning and return an error.
The third case is impossible exactly because of the same reason as the
second case. The given delayed item matches one item in the leaf, so we
know that our batch always has at least one item. Add an ASSERT to check
that, trigger a warning if that expectation fails and return an error.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When reflinking extents (clone and deduplication), we need to touch the
btree of the destination inode's subvolume, as well as potentially
create a delayed inode for the destination inode (if it was not created
before). However we are neither balancing the btree dirty pages nor the
delayed items after such operations, so if we have a task that is doing
a long series of clone or deduplication operations, it can result in
accumulation of too many btree dirty pages and delayed items.
So just call btrfs_btree_balance_dirty() after clone and deduplication,
just like we do for every other system call that results on modifying a
btree and adding delayed items.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When creating an inode, through btrfs_create_new_inode(), we release the
path we allocated before once we don't need it anymore. But we keep it
allocated until we return from that function, which is wasteful because
after we release the path we do several things that can allocate yet
another path: inheriting properties, setting the xattrs used by ACLs and
secutiry modules, adding an orphan item (O_TMPFILE case) or adding a
dir item (for the non-O_TMPFILE case).
So instead of releasing the path once we don't need it anymore, free it
instead. This way we avoid having two paths allocated until we return
from btrfs_create_new_inode().
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
A rename operation modifies a subvolume's btree, to remove the old dir
item, add the new dir item, remove an inode ref and add a new inode ref.
It can also create the delayed inode for the inodes involved in the
operation, and it creates two delayed dir index items, one to delete
the old name and another one to add the new name.
However we are neither balancing the btree dirty pages nor the delayed
items after a rename, which can result in accumulation of too many
btree dirty pages and delayed items, specially if a task is doing a
series of rename operations (for example it can happen for package
installations/upgrades through the zypper tool).
So just call btrfs_btree_balance_dirty() after a rename, just like we
do for every other system call that results on modifying a btree and
adding delayed items.
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Add tracepoint for better insight to how the RAID56 data are submitted.
The output looks like this: (trace event header and UUID skipped)
raid56_read_partial: full_stripe=389152768 devid=3 type=DATA1 offset=32768 opf=0x0 physical=323059712 len=32768
raid56_read_partial: full_stripe=389152768 devid=1 type=DATA2 offset=0 opf=0x0 physical=67174400 len=65536
raid56_write_stripe: full_stripe=389152768 devid=3 type=DATA1 offset=0 opf=0x1 physical=323026944 len=32768
raid56_write_stripe: full_stripe=389152768 devid=2 type=PQ1 offset=0 opf=0x1 physical=323026944 len=32768
The above debug output is from a 32K data write into an empty RAID56
data chunk.
Some explanation on the event output:
full_stripe: the logical bytenr of the full stripe
devid: btrfs devid
type: raid stripe type.
DATA1: the first data stripe
DATA2: the second data stripe
PQ1: the P stripe
PQ2: the Q stripe
offset: the offset inside the stripe.
opf: the bio op type
physical: the physical offset the bio is for
len: the length of the bio
The first two lines are from partial RMW read, which is reading the
remaining data stripes from disks.
The last two lines are for full stripe RMW write, which is writing the
involved two 16K stripes (one for DATA1 stripe, one for P stripe).
The stripe for DATA2 doesn't need to be written.
There are 5 types of trace events:
- raid56_read_partial
Read remaining data for regular read/write path.
- raid56_write_stripe
Write the modified stripes for regular read/write path.
- raid56_scrub_read_recover
Read remaining data for scrub recovery path.
- raid56_scrub_write_stripe
Write the modified stripes for scrub path.
- raid56_scrub_read
Read remaining data for scrub path.
Also, since the trace events are included at super.c, we have to export
needed structure definitions to 'raid56.h' and include the header in
super.c, or we're unable to access those members.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ reformat comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
[BUG]
With added debugging, it turns out the following write sequence would
cause extra read which is unnecessary:
# xfs_io -f -s -c "pwrite -b 32k 0 32k" -c "pwrite -b 32k 32k 32k" \
-c "pwrite -b 32k 64k 32k" -c "pwrite -b 32k 96k 32k" \
$mnt/file
The debug message looks like this (btrfs header skipped):
partial rmw, full stripe=389152768 opf=0x0 devid=3 type=1 offset=32768 physical=323059712 len=32768
partial rmw, full stripe=389152768 opf=0x0 devid=1 type=2 offset=0 physical=67174400 len=65536
full stripe rmw, full stripe=389152768 opf=0x1 devid=3 type=1 offset=0 physical=323026944 len=32768
full stripe rmw, full stripe=389152768 opf=0x1 devid=2 type=-1 offset=0 physical=323026944 len=32768
partial rmw, full stripe=298844160 opf=0x0 devid=1 type=1 offset=32768 physical=22052864 len=32768
partial rmw, full stripe=298844160 opf=0x0 devid=2 type=2 offset=0 physical=277872640 len=65536
full stripe rmw, full stripe=298844160 opf=0x1 devid=1 type=1 offset=0 physical=22020096 len=32768
full stripe rmw, full stripe=298844160 opf=0x1 devid=3 type=-1 offset=0 physical=277872640 len=32768
partial rmw, full stripe=389152768 opf=0x0 devid=3 type=1 offset=0 physical=323026944 len=32768
partial rmw, full stripe=389152768 opf=0x0 devid=1 type=2 offset=0 physical=67174400 len=65536
^^^^
Still partial read, even 389152768 is already cached by the first.
write.
full stripe rmw, full stripe=389152768 opf=0x1 devid=3 type=1 offset=32768 physical=323059712 len=32768
full stripe rmw, full stripe=389152768 opf=0x1 devid=2 type=-1 offset=32768 physical=323059712 len=32768
partial rmw, full stripe=298844160 opf=0x0 devid=1 type=1 offset=0 physical=22020096 len=32768
partial rmw, full stripe=298844160 opf=0x0 devid=2 type=2 offset=0 physical=277872640 len=65536
^^^^
Still partial read for 298844160.
full stripe rmw, full stripe=298844160 opf=0x1 devid=1 type=1 offset=32768 physical=22052864 len=32768
full stripe rmw, full stripe=298844160 opf=0x1 devid=3 type=-1 offset=32768 physical=277905408 len=32768
This means every 32K writes, even they are in the same full stripe,
still trigger read for previously cached data.
This would cause extra RAID56 IO, making the btrfs raid56 cache useless.
[CAUSE]
Commit d4e28d9b5f04 ("btrfs: raid56: make steal_rbio() subpage
compatible") tries to make steal_rbio() subpage compatible, but during
that conversion, there is one thing missing.
We no longer rely on PageUptodate(rbio->stripe_pages[i]), but
rbio->stripe_nsectors[i].uptodate to determine if a sector is uptodate.
This means, previously if we switch the pointer, everything is done,
as the PageUptodate flag is still bound to that page.
But now we have to manually mark the involved sectors uptodate, or later
raid56_rmw_stripe() will find the stolen sector is not uptodate, and
assemble the read bio for it, wasting IO.
[FIX]
We can easily fix the bug, by also update the
rbio->stripe_sectors[].uptodate in steal_rbio().
With this fixed, now the same write pattern no longer leads to the same
unnecessary read:
partial rmw, full stripe=389152768 opf=0x0 devid=3 type=1 offset=32768 physical=323059712 len=32768
partial rmw, full stripe=389152768 opf=0x0 devid=1 type=2 offset=0 physical=67174400 len=65536
full stripe rmw, full stripe=389152768 opf=0x1 devid=3 type=1 offset=0 physical=323026944 len=32768
full stripe rmw, full stripe=389152768 opf=0x1 devid=2 type=-1 offset=0 physical=323026944 len=32768
partial rmw, full stripe=298844160 opf=0x0 devid=1 type=1 offset=32768 physical=22052864 len=32768
partial rmw, full stripe=298844160 opf=0x0 devid=2 type=2 offset=0 physical=277872640 len=65536
full stripe rmw, full stripe=298844160 opf=0x1 devid=1 type=1 offset=0 physical=22020096 len=32768
full stripe rmw, full stripe=298844160 opf=0x1 devid=3 type=-1 offset=0 physical=277872640 len=32768
^^^ No more partial read, directly into the write path.
full stripe rmw, full stripe=389152768 opf=0x1 devid=3 type=1 offset=32768 physical=323059712 len=32768
full stripe rmw, full stripe=389152768 opf=0x1 devid=2 type=-1 offset=32768 physical=323059712 len=32768
full stripe rmw, full stripe=298844160 opf=0x1 devid=1 type=1 offset=32768 physical=22052864 len=32768
full stripe rmw, full stripe=298844160 opf=0x1 devid=3 type=-1 offset=32768 physical=277905408 len=32768
Fixes: d4e28d9b5f04 ("btrfs: raid56: make steal_rbio() subpage compatible")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Both memzero_page and memcpy_to_page already call flush_dcache_page so
we can remove the calls from btrfs code.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
If we have only 8K partial write at the beginning of a full RAID56
stripe, we will write the following contents:
0 8K 32K 64K
Disk 1 (data): |XX| | |
Disk 2 (data): | | |
Disk 3 (parity): |XXXXXXXXXXXXXXX|XXXXXXXXXXXXXXX|
|X| means the sector will be written back to disk.
Note that, although we won't write any sectors from disk 2, but we will
write the full 64KiB of parity to disk.
This behavior is fine for now, but not for the future (especially for
RAID56J, as we waste quite some space to journal the unused parity
stripes).
So here we will also utilize the btrfs_raid_bio::dbitmap, anytime we
queue a higher level bio into an rbio, we will update rbio::dbitmap to
indicate which vertical stripes we need to writeback.
And at finish_rmw(), we also check dbitmap to see if we need to write
any sector in the vertical stripe.
So after the patch, above example will only lead to the following
writeback pattern:
0 8K 32K 64K
Disk 1 (data): |XX| | |
Disk 2 (data): | | |
Disk 3 (parity): |XX| | |
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Previously we use "unsigned long *" for those two bitmaps.
But since we only support fixed stripe length (64KiB, already checked in
tree-checker), "unsigned long *" is really a waste of memory, while we
can just use "unsigned long".
This saves us 8 bytes in total for scrub_parity.
To be extra safe, add an ASSERT() making sure calclulated @nsectors is
always smaller than BITS_PER_LONG.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Previsouly we use "unsigned long *" for those two bitmaps.
But since we only support fixed stripe length (64KiB, already checked in
tree-checker), "unsigned long *" is really a waste of memory, while we
can just use "unsigned long".
This saves us 8 bytes in total for btrfs_raid_bio.
To be extra safe, add an ASSERT() making sure calculated
@stripe_nsectors is always smaller than BITS_PER_LONG.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This eliminates 2 labels and makes the code generally more streamlined.
Also rename the 'out_bargs' label to 'out_unlock' since bargs is going
to be freed under the 'out' label. This also fixes a memory leak since
bargs wasn't correctly freed in one of the condition which are now moved
in btrfs_try_lock_balance.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This function contains the factored out locking sequence of
btrfs_ioctl_balance. Having this piece of code separate helps to
simplify btrfs_ioctl_balance which has too complicated. This will be
used in the next patch to streamline the logic in btrfs_ioctl_balance.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Use the new btrfs_bio_for_each_sector iterator to simplify
btrfs_check_read_dio_bio.
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.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 a helper that works similar to __bio_for_each_segment, but instead of
iterating over PAGE_SIZE chunks it iterates over each sector.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
[hch: split from a larger patch, and iterate over the offset instead of
the offset bits]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add parameter comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
Add a helper to find the csum for a byte offset into the csum buffer.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Untangle the goto and move the code it jumps to so it goes in the order
of the most likely states first.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
Add a helper to end I/O on a single sector, which will come in handy
with the new read repair code.
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.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 function submit_data_read_repair() is only called for buffered data
read path, thus those members can be calculated using bvec directly:
- start
start = page_offset(bvec->bv_page) + bvec->bv_offset;
- end
end = start + bvec->bv_len - 1;
- page
page = bvec->bv_page;
- pgoff
pgoff = bvec->bv_offset;
Thus we can safely replace those 4 parameters with just one bio_vec.
Also remove the unused return value.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
[hch: also remove the return value]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David Sterba <dsterba@suse.com>
Although we have several data csum verification code, we never have a
function really just to verify checksum for one sector.
Function check_data_csum() do extra work for error reporting, thus it
requires a lot of extra things like file offset, bio_offset etc.
Function btrfs_verify_data_csum() is even worse, it will utilize page
checked flag, which means it can not be utilized for direct IO pages.
Here we introduce a new helper, btrfs_check_sector_csum(), which really
only accept a sector in page, and expected checksum pointer.
We use this function to implement check_data_csum(), and export it for
incoming patch.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
[hch: keep passing the csum array as an arguments, as the callers want
to print it, rename per request]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The following functions do special handling for RAID56 chunks:
- btrfs_is_parity_mirror()
Check if the range is in RAID56 chunks.
- btrfs_full_stripe_len()
Either return sectorsize for non-RAID56 profiles or full stripe length
for RAID56 chunks.
But if a filesystem without any RAID56 chunks, it will not have RAID56
incompat flags, and we can skip the chunk tree looking up completely.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Qu Wenruo <wqu@suse.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 <linux/mm.h> already provides the PAGE_ALIGNED macro. Let's
use it instead of IS_ALIGNED and passing PAGE_SIZE directly.
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Fanjun Kong <bh1scw@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Fix the comment to represent the actual logic used for sb_write_pointer
- Empty[0] && In use[1] should be an invalid state instead of returning
zone 0 wp
- Empty[0] && Full[1] should be returning zone 0 wp instead of zone 1 wp
- In use[0] && Empty[1] should be returning zone 0 wp instead of being an
invalid state
- In use[0] && Full[1] should be returning zone 0 wp instead of returning
zone 1 wp
- Full[0] && Empty[1] should be returning zone 1 wp instead of returning
zone 0 wp
- Full[0] && In use[1] should be returning zone 1 wp instead of returning
zone 0 wp
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Pankaj Raghav <p.raghav@samsung.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Merge tag 'for-5.19-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs reverts from David Sterba:
"Due to a recent report [1] we need to revert the radix tree to xarray
conversion patches.
There's a problem with sleeping under spinlock, when xa_insert could
allocate memory under pressure. We use GFP_NOFS so this is a real
problem that we unfortunately did not discover during review.
I'm sorry to do such change at rc6 time but the revert is IMO the
safer option, there are patches to use mutex instead of the spin locks
but that would need more testing. The revert branch has been tested on
a few setups, all seem ok.
The conversion to xarray will be revisited in the future"
Link: https://lore.kernel.org/linux-btrfs/cover.1657097693.git.fdmanana@suse.com/ [1]
* tag 'for-5.19-rc7-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Revert "btrfs: turn delayed_nodes_tree into an XArray"
Revert "btrfs: turn name_cache radix tree into XArray in send_ctx"
Revert "btrfs: turn fs_info member buffer_radix into XArray"
Revert "btrfs: turn fs_roots_radix in btrfs_fs_info into an XArray"
This reverts commit 253bf57555e451dec5a7f09dc95d380ce8b10e5b.
Revert the xarray conversion, there's a problem with potential
sleep-inside-spinlock [1] when calling xa_insert that triggers GFP_NOFS
allocation. The radix tree used the preloading mechanism to avoid
sleeping but this is not available in xarray.
Conversion from spin lock to mutex is possible but at time of rc6 is
riskier than a clean revert.
[1] https://lore.kernel.org/linux-btrfs/cover.1657097693.git.fdmanana@suse.com/
Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This reverts commit 4076942021fe14efecae33bf98566df6dd5ae6f7.
Revert the xarray conversion, there's a problem with potential
sleep-inside-spinlock [1] when calling xa_insert that triggers GFP_NOFS
allocation. The radix tree used the preloading mechanism to avoid
sleeping but this is not available in xarray.
Conversion from spin lock to mutex is possible but at time of rc6 is
riskier than a clean revert.
[1] https://lore.kernel.org/linux-btrfs/cover.1657097693.git.fdmanana@suse.com/
Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This reverts commit 8ee922689d67b7cfa6acbe2aa1ee76ac72e6fc8a.
Revert the xarray conversion, there's a problem with potential
sleep-inside-spinlock [1] when calling xa_insert that triggers GFP_NOFS
allocation. The radix tree used the preloading mechanism to avoid
sleeping but this is not available in xarray.
Conversion from spin lock to mutex is possible but at time of rc6 is
riskier than a clean revert.
[1] https://lore.kernel.org/linux-btrfs/cover.1657097693.git.fdmanana@suse.com/
Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This reverts commit 48b36a602a335c184505346b5b37077840660634.
Revert the xarray conversion, there's a problem with potential
sleep-inside-spinlock [1] when calling xa_insert that triggers GFP_NOFS
allocation. The radix tree used the preloading mechanism to avoid
sleeping but this is not available in xarray.
Conversion from spin lock to mutex is possible but at time of rc6 is
riskier than a clean revert.
[1] https://lore.kernel.org/linux-btrfs/cover.1657097693.git.fdmanana@suse.com/
Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for
variables that represent request flags.
Acked-by: David Sterba <dsterba@suse.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-51-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Merge tag 'for-5.19-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
"A more fixes that seem to me to be important enough to get merged
before release:
- in zoned mode, fix leak of a structure when reading zone info, this
happens on normal path so this can be significant
- in zoned mode, revert an optimization added in 5.19-rc1 to finish a
zone when the capacity is full, but this is not reliable in all
cases
- try to avoid short reads for compressed data or inline files when
it's a NOWAIT read, applications should handle that but there are
two, qemu and mariadb, that are affected"
* tag 'for-5.19-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: zoned: drop optimization of zone finish
btrfs: zoned: fix a leaked bioc in read_zone_info
btrfs: return -EAGAIN for NOWAIT dio reads/writes on compressed and inline extents
We have an optimization in do_zone_finish() to send REQ_OP_ZONE_FINISH only
when necessary, i.e. we don't send REQ_OP_ZONE_FINISH when we assume we
wrote fully into the zone.
The assumption is determined by "alloc_offset == capacity". This condition
won't work if the last ordered extent is canceled due to some errors. In
that case, we consider the zone is deactivated without sending the finish
command while it's still active.
This inconstancy results in activating another block group while we cannot
really activate the underlying zone, which causes the active zone exceeds
errors like below.
BTRFS error (device nvme3n2): allocation failed flags 1, wanted 520192 tree-log 0, relocation: 0
nvme3n2: I/O Cmd(0x7d) @ LBA 160432128, 127 blocks, I/O Error (sct 0x1 / sc 0xbd) MORE DNR
active zones exceeded error, dev nvme3n2, sector 0 op 0xd:(ZONE_APPEND) flags 0x4800 phys_seg 1 prio class 0
nvme3n2: I/O Cmd(0x7d) @ LBA 160432128, 127 blocks, I/O Error (sct 0x1 / sc 0xbd) MORE DNR
active zones exceeded error, dev nvme3n2, sector 0 op 0xd:(ZONE_APPEND) flags 0x4800 phys_seg 1 prio class 0
Fix the issue by removing the optimization for now.
Fixes: 8376d9e1ed8f ("btrfs: zoned: finish superblock zone once no space left for new SB")
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
The bioc would leak on the normal completion path and also on the RAID56
check (but that one won't happen in practice due to the invalid
combination with zoned mode).
Fixes: 7db1c5d14dcd ("btrfs: zoned: support dev-replace in zoned filesystems")
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[ update changelog ]
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When doing a direct IO read or write, we always return -ENOTBLK when we
find a compressed extent (or an inline extent) so that we fallback to
buffered IO. This however is not ideal in case we are in a NOWAIT context
(io_uring for example), because buffered IO can block and we currently
have no support for NOWAIT semantics for buffered IO, so if we need to
fallback to buffered IO we should first signal the caller that we may
need to block by returning -EAGAIN instead.
This behaviour can also result in short reads being returned to user
space, which although it's not incorrect and user space should be able
to deal with partial reads, it's somewhat surprising and even some popular
applications like QEMU (Link tag #1) and MariaDB (Link tag #2) don't
deal with short reads properly (or at all).
The short read case happens when we try to read from a range that has a
non-compressed and non-inline extent followed by a compressed extent.
After having read the first extent, when we find the compressed extent we
return -ENOTBLK from btrfs_dio_iomap_begin(), which results in iomap to
treat the request as a short read, returning 0 (success) and waiting for
previously submitted bios to complete (this happens at
fs/iomap/direct-io.c:__iomap_dio_rw()). After that, and while at
btrfs_file_read_iter(), we call filemap_read() to use buffered IO to
read the remaining data, and pass it the number of bytes we were able to
read with direct IO. Than at filemap_read() if we get a page fault error
when accessing the read buffer, we return a partial read instead of an
-EFAULT error, because the number of bytes previously read is greater
than zero.
So fix this by returning -EAGAIN for NOWAIT direct IO when we find a
compressed or an inline extent.
Reported-by: Dominique MARTINET <dominique.martinet@atmark-techno.com>
Link: https://lore.kernel.org/linux-btrfs/YrrFGO4A1jS0GI0G@atmark-techno.com/
Link: https://jira.mariadb.org/browse/MDEV-27900?focusedCommentId=216582&page=com.atlassian.jira.plugin.system.issuetabpanels%3Acomment-tabpanel#comment-216582
Tested-by: Dominique MARTINET <dominique.martinet@atmark-techno.com>
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Currently shrinkers are anonymous objects. For debugging purposes they
can be identified by count/scan function names, but it's not always
useful: e.g. for superblock's shrinkers it's nice to have at least an
idea of to which superblock the shrinker belongs.
This commit adds names to shrinkers. register_shrinker() and
prealloc_shrinker() functions are extended to take a format and arguments
to master a name.
In some cases it's not possible to determine a good name at the time when
a shrinker is allocated. For such cases shrinker_debugfs_rename() is
provided.
The expected format is:
<subsystem>-<shrinker_type>[:<instance>]-<id>
For some shrinkers an instance can be encoded as (MAJOR:MINOR) pair.
After this change the shrinker debugfs directory looks like:
$ cd /sys/kernel/debug/shrinker/
$ ls
dquota-cache-16 sb-devpts-28 sb-proc-47 sb-tmpfs-42
mm-shadow-18 sb-devtmpfs-5 sb-proc-48 sb-tmpfs-43
mm-zspool:zram0-34 sb-hugetlbfs-17 sb-pstore-31 sb-tmpfs-44
rcu-kfree-0 sb-hugetlbfs-33 sb-rootfs-2 sb-tmpfs-49
sb-aio-20 sb-iomem-12 sb-securityfs-6 sb-tracefs-13
sb-anon_inodefs-15 sb-mqueue-21 sb-selinuxfs-22 sb-xfs:vda1-36
sb-bdev-3 sb-nsfs-4 sb-sockfs-8 sb-zsmalloc-19
sb-bpf-32 sb-pipefs-14 sb-sysfs-26 thp-deferred_split-10
sb-btrfs:vda2-24 sb-proc-25 sb-tmpfs-1 thp-zero-9
sb-cgroup2-30 sb-proc-39 sb-tmpfs-27 xfs-buf:vda1-37
sb-configfs-23 sb-proc-41 sb-tmpfs-29 xfs-inodegc:vda1-38
sb-dax-11 sb-proc-45 sb-tmpfs-35
sb-debugfs-7 sb-proc-46 sb-tmpfs-40
[roman.gushchin@linux.dev: fix build warnings]
Link: https://lkml.kernel.org/r/Yr+ZTnLb9lJk6fJO@castle
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lkml.kernel.org/r/20220601032227.4076670-4-roman.gushchin@linux.dev
Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Hillf Danton <hdanton@sina.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Merge tag 'for-5.19-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- zoned relocation fixes:
- fix critical section end for extent writeback, this could lead
to out of order write
- prevent writing to previous data relocation block group if space
gets low
- reflink fixes:
- fix race between reflinking and ordered extent completion
- proper error handling when block reserve migration fails
- add missing inode iversion/mtime/ctime updates on each iteration
when replacing extents
- fix deadlock when running fsync/fiemap/commit at the same time
- fix false-positive KCSAN report regarding pid tracking for read locks
and data race
- minor documentation update and link to new site
* tag 'for-5.19-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
Documentation: update btrfs list of features and link to readthedocs.io
btrfs: fix deadlock with fsync+fiemap+transaction commit
btrfs: don't set lock_owner when locking extent buffer for reading
btrfs: zoned: fix critical section of relocation inode writeback
btrfs: zoned: prevent allocation from previous data relocation BG
btrfs: do not BUG_ON() on failure to migrate space when replacing extents
btrfs: add missing inode updates on each iteration when replacing extents
btrfs: fix race between reflinking and ordered extent completion
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Merge tag 'for-5.19-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
- print more error messages for invalid mount option values
- prevent remount with v1 space cache for subpage filesystem
- fix hang during unmount when block group reclaim task is running
* tag 'for-5.19-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
btrfs: add error messages to all unrecognized mount options
btrfs: prevent remounting to v1 space cache for subpage mount
btrfs: fix hang during unmount when block group reclaim task is running
We are hitting the following deadlock in production occasionally
Task 1 Task 2 Task 3 Task 4 Task 5
fsync(A)
start trans
start commit
falloc(A)
lock 5m-10m
start trans
wait for commit
fiemap(A)
lock 0-10m
wait for 5m-10m
(have 0-5m locked)
have btrfs_need_log_full_commit
!full_sync
wait_ordered_extents
finish_ordered_io(A)
lock 0-5m
DEADLOCK
We have an existing dependency of file extent lock -> transaction.
However in fsync if we tried to do the fast logging, but then had to
fall back to committing the transaction, we will be forced to call
btrfs_wait_ordered_range() to make sure all of our extents are updated.
This creates a dependency of transaction -> file extent lock, because
btrfs_finish_ordered_io() will need to take the file extent lock in
order to run the ordered extents.
Fix this by stopping the transaction if we have to do the full commit
and we attempted to do the fast logging. Then attach to the transaction
and commit it if we need to.
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
In 196d59ab9ccc "btrfs: switch extent buffer tree lock to rw_semaphore"
the functions for tree read locking were rewritten, and in the process
the read lock functions started setting eb->lock_owner = current->pid.
Previously lock_owner was only set in tree write lock functions.
Read locks are shared, so they don't have exclusive ownership of the
underlying object, so setting lock_owner to any single value for a
read lock makes no sense. It's mostly harmless because write locks
and read locks are mutually exclusive, and none of the existing code
in btrfs (btrfs_init_new_buffer and print_eb_refs_lock) cares what
nonsense is written in lock_owner when no writer is holding the lock.
KCSAN does care, and will complain about the data race incessantly.
Remove the assignments in the read lock functions because they're
useless noise.
Fixes: 196d59ab9ccc ("btrfs: switch extent buffer tree lock to rw_semaphore")
CC: stable@vger.kernel.org # 5.15+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Signed-off-by: David Sterba <dsterba@suse.com>
We use btrfs_zoned_data_reloc_{lock,unlock} to allow only one process to
write out to the relocation inode. That critical section must include all
the IO submission for the inode. However, flush_write_bio() in
extent_writepages() is out of the critical section, causing an IO
submission outside of the lock. This leads to an out of the order IO
submission and fail the relocation process.
Fix it by extending the critical section.
Fixes: 35156d852762 ("btrfs: zoned: only allow one process to add pages to a relocation inode")
CC: stable@vger.kernel.org # 5.16+
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
After commit 5f0addf7b890 ("btrfs: zoned: use dedicated lock for data
relocation"), we observe IO errors on e.g, btrfs/232 like below.
[09.0][T4038707] WARNING: CPU: 3 PID: 4038707 at fs/btrfs/extent-tree.c:2381 btrfs_cross_ref_exist+0xfc/0x120 [btrfs]
<snip>
[09.9][T4038707] Call Trace:
[09.5][T4038707] <TASK>
[09.3][T4038707] run_delalloc_nocow+0x7f1/0x11a0 [btrfs]
[09.6][T4038707] ? test_range_bit+0x174/0x320 [btrfs]
[09.2][T4038707] ? fallback_to_cow+0x980/0x980 [btrfs]
[09.3][T4038707] ? find_lock_delalloc_range+0x33e/0x3e0 [btrfs]
[09.5][T4038707] btrfs_run_delalloc_range+0x445/0x1320 [btrfs]
[09.2][T4038707] ? test_range_bit+0x320/0x320 [btrfs]
[09.4][T4038707] ? lock_downgrade+0x6a0/0x6a0
[09.2][T4038707] ? orc_find.part.0+0x1ed/0x300
[09.5][T4038707] ? __module_address.part.0+0x25/0x300
[09.0][T4038707] writepage_delalloc+0x159/0x310 [btrfs]
<snip>
[09.4][ C3] sd 10:0:1:0: [sde] tag#2620 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_OK cmd_age=0s
[09.5][ C3] sd 10:0:1:0: [sde] tag#2620 Sense Key : Illegal Request [current]
[09.9][ C3] sd 10:0:1:0: [sde] tag#2620 Add. Sense: Unaligned write command
[09.5][ C3] sd 10:0:1:0: [sde] tag#2620 CDB: Write(16) 8a 00 00 00 00 00 02 f3 63 87 00 00 00 2c 00 00
[09.4][ C3] critical target error, dev sde, sector 396041272 op 0x1:(WRITE) flags 0x800 phys_seg 3 prio class 0
[09.9][ C3] BTRFS error (device dm-1): bdev /dev/mapper/dml_102_2 errs: wr 1, rd 0, flush 0, corrupt 0, gen 0
The IO errors occur when we allocate a regular extent in previous data
relocation block group.
On zoned btrfs, we use a dedicated block group to relocate a data
extent. Thus, we allocate relocating data extents (pre-alloc) only from
the dedicated block group and vice versa. Once the free space in the
dedicated block group gets tight, a relocating extent may not fit into
the block group. In that case, we need to switch the dedicated block
group to the next one. Then, the previous one is now freed up for
allocating a regular extent. The BG is already not enough to allocate
the relocating extent, but there is still room to allocate a smaller
extent. Now the problem happens. By allocating a regular extent while
nocow IOs for the relocation is still on-going, we will issue WRITE IOs
(for relocation) and ZONE APPEND IOs (for the regular writes) at the
same time. That mixed IOs confuses the write pointer and arises the
unaligned write errors.
This commit introduces a new bit 'zoned_data_reloc_ongoing' to the
btrfs_block_group. We set this bit before releasing the dedicated block
group, and no extent are allocated from a block group having this bit
set. This bit is similar to setting block_group->ro, but is different from
it by allowing nocow writes to start.
Once all the nocow IO for relocation is done (hooked from
btrfs_finish_ordered_io), we reset the bit to release the block group for
further allocation.
Fixes: c2707a255623 ("btrfs: zoned: add a dedicated data relocation block group")
CC: stable@vger.kernel.org # 5.16+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
At btrfs_replace_file_extents(), if we fail to migrate reserved metadata
space from the transaction block reserve into the local block reserve,
we trigger a BUG_ON(). This is because it should not be possible to have
a failure here, as we reserved more space when we started the transaction
than the space we want to migrate. However having a BUG_ON() is way too
drastic, we can perfectly handle the failure and return the error to the
caller. So just do that instead, and add a WARN_ON() to make it easier
to notice the failure if it ever happens (which is particularly useful
for fstests, and the warning will trigger a failure of a test case).
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
When replacing file extents, called during fallocate, hole punching,
clone and deduplication, we may not be able to replace/drop all the
target file extent items with a single transaction handle. We may get
-ENOSPC while doing it, in which case we release the transaction handle,
balance the dirty pages of the btree inode, flush delayed items and get
a new transaction handle to operate on what's left of the target range.
By dropping and replacing file extent items we have effectively modified
the inode, so we should bump its iversion and update its mtime/ctime
before we update the inode item. This is because if the transaction
we used for partially modifying the inode gets committed by someone after
we release it and before we finish the rest of the range, a power failure
happens, then after mounting the filesystem our inode has an outdated
iversion and mtime/ctime, corresponding to the values it had before we
changed it.
So add the missing iversion and mtime/ctime updates.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
While doing a reflink operation, if an ordered extent for a file range
that does not overlap with the source and destination ranges of the
reflink operation happens, we can end up having a failure in the reflink
operation and return -EINVAL to user space.
The following sequence of steps explains how this can happen:
1) We have the page at file offset 315392 dirty (under delalloc);
2) A reflink operation for this file starts, using the same file as both
source and destination, the source range is [372736, 409600) (length of
36864 bytes) and the destination range is [208896, 245760);
3) At btrfs_remap_file_range_prep(), we flush all delalloc in the source
and destination ranges, and wait for any ordered extents in those range
to complete;
4) Still at btrfs_remap_file_range_prep(), we then flush all delalloc in
the inode, but we neither wait for it to complete nor any ordered
extents to complete. This results in starting delalloc for the page at
file offset 315392 and creating an ordered extent for that single page
range;
5) We then move to btrfs_clone() and enter the loop to find file extent
items to copy from the source range to destination range;
6) In the first iteration we end up at last file extent item stored in
leaf A:
(...)
item 131 key (143616 108 315392) itemoff 5101 itemsize 53
extent data disk bytenr 1903988736 nr 73728
extent data offset 12288 nr 61440 ram 73728
This represents the file range [315392, 376832), which overlaps with
the source range to clone.
@datal is set to 61440, key.offset is 315392 and @next_key_min_offset
is therefore set to 376832 (315392 + 61440).
@off (372736) is > key.offset (315392), so @new_key.offset is set to
the value of @destoff (208896).
@new_key.offset == @last_dest_end (208896) so @drop_start is set to
208896 (@new_key.offset).
@datal is adjusted to 4096, as @off is > @key.offset.
So in this iteration we call btrfs_replace_file_extents() for the range
[208896, 212991] (a single page, which is
[@drop_start, @new_key.offset + @datal - 1]).
@last_dest_end is set to 212992 (@new_key.offset + @datal =
208896 + 4096 = 212992).
Before the next iteration of the loop, @key.offset is set to the value
376832, which is @next_key_min_offset;
7) On the second iteration btrfs_search_slot() leaves us again at leaf A,
but this time pointing beyond the last slot of leaf A, as that's where
a key with offset 376832 should be at if it existed. So end up calling
btrfs_next_leaf();
8) btrfs_next_leaf() releases the path, but before it searches again the
tree for the next key/leaf, the ordered extent for the single page
range at file offset 315392 completes. That results in trimming the
file extent item we processed before, adjusting its key offset from
315392 to 319488, reducing its length from 61440 to 57344 and inserting
a new file extent item for that single page range, with a key offset of
315392 and a length of 4096.
Leaf A now looks like:
(...)
item 132 key (143616 108 315392) itemoff 4995 itemsize 53
extent data disk bytenr 1801666560 nr 4096
extent data offset 0 nr 4096 ram 4096
item 133 key (143616 108 319488) itemoff 4942 itemsize 53
extent data disk bytenr 1903988736 nr 73728
extent data offset 16384 nr 57344 ram 73728
9) When btrfs_next_leaf() returns, it gives us a path pointing to leaf A
at slot 133, since it's the first key that follows what was the last
key we saw (143616 108 315392). In fact it's the same item we processed
before, but its key offset was changed, so it counts as a new key;
10) So now we have:
@key.offset == 319488
@datal == 57344
@off (372736) is > key.offset (319488), so @new_key.offset is set to
208896 (@destoff value).
@new_key.offset (208896) != @last_dest_end (212992), so @drop_start
is set to 212992 (@last_dest_end value).
@datal is adjusted to 4096 because @off > @key.offset.
So in this iteration we call btrfs_replace_file_extents() for the
invalid range of [212992, 212991] (which is
[@drop_start, @new_key.offset + @datal - 1]).
This range is empty, the end offset is smaller than the start offset
so btrfs_replace_file_extents() returns -EINVAL, which we end up
returning to user space and fail the reflink operation.
This all happens because the range of this file extent item was
already processed in the previous iteration.
This scenario can be triggered very sporadically by fsx from fstests, for
example with test case generic/522.
So fix this by having btrfs_clone() skip file extent items that cover a
file range that we have already processed.
CC: stable@vger.kernel.org # 5.10+
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
