Code that uses for_each_btree_key often wants transaction restarts to be
handled locally and not returned. Originally, we wouldn't return
transaction restarts if there was a single iterator in the transaction -
the reasoning being if there weren't other iterators being invalidated,
and the current iterator was being advanced/retraversed, there weren't
any locks or iterators we were required to preserve.
But with the btree_path conversion that approach doesn't work anymore -
even when we're using for_each_btree_key() with a single iterator there
will still be two paths in the transaction, since we now always preserve
the path at the pos the iterator was initialized at - the reason being
that on restart we often restart from the same place.
And it turns out there's now a lot of for_each_btree_key() uses that _do
not_ want transaction restarts handled locally, and should be returning
them.
This patch splits out for_each_btree_key_norestart() and
for_each_btree_key_continue_norestart(), and converts existing users as
appropriate. for_each_btree_key(), for_each_btree_key_continue(), and
for_each_btree_node() now handle transaction restarts themselves by
calling bch2_trans_begin() when necessary - and the old hack to not
return transaction restarts when there's a single path in the
transaction has been deleted.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Now that peek_node()/next_node() are converted to return errors
directly, we don't need bch2_trans_exit() to return errors - it's
cleaner this way and wasn't used much anymore.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This plumbs around the subvolume ID as was done previously for other
filesystem code, but now for the IO paths - the control flow in the IO
paths is trickier so the changes in this patch are more involved.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
To implement snapshots, we need every filesystem btree operation (every
btree operation without a subvolume) to start by looking up the
subvolume and getting the current snapshot ID, with
bch2_subvolume_get_snapshot() - then, that snapshot ID is used for doing
btree lookups in BTREE_ITER_FILTER_SNAPSHOTS mode.
This patch adds those bch2_subvolume_get_snapshot() calls, and also
switches to passing around a subvol_inum instead of just an inode
number.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This splits btree_iter into two components: btree_iter is now the
externally visible componont, and it points to a btree_path which is now
reference counted.
This means we no longer have to clone iterators up front if they might
be mutated - btree_path can be shared by multiple iterators, and cloned
if an iterator would mutate a shared btree_path. This will help us use
iterators more efficiently, as well as slimming down the main long lived
state in btree_trans, and significantly cleans up the logic for iterator
lifetimes.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
__bch2_read() -> __bch2_read_extent() -> bch2_bucket_io_time_reset() may
cause a transaction restart, which we don't return an error for because
it doesn't prevent us from making forward progress on the read we're
submitting.
Instead, change __bch2_read() and bchfs_read() to check for transaction
restarts.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Upcoming patch will require that a transaction restart is always
immediately followed by bch2_trans_begin().
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
On transaction restart iterators won't be locked anymore - make sure
we're always checking for errors.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
This is needed for snapshots because we need to start handling lock
restarts even when just calling bch2_inode_peek().
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Do not attempt to shortcut a truncate when the given new size is
the same as the current size. There may be blocks allocated to the
file that extend beyond the i_size. The ctime and mtime should
not be updated in this case.
Signed-off-by: Dan Robertson <dan@dlrobertson.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
After the v5.12 rebase, we started oopsing when truncate was passed
ATTR_MODE, due to not passing mnt_userns to setattr_copy(). This
refactors things so that truncate/extend finish by using
bch2_setattr_nonsize(), which solves the problem.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Adding iter->should_be_locked introduced a regression where it ended up
not being set on the iterator passed to bch2_btree_update_start(), which
is definitely not what we want.
This patch requires it to be set when calling bch2_trans_update(), and
adds various fixups to make that happen.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Commit c42bca92be "bio: don't copy bvec
for direct IO" changed bio_iov_iter_get_pages() to point bio->bi_iovec
at the incoming biovec, meaning if we already allocated one, it'll be
leaked.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
We already had op->end_io as an alternative mechanism to op->cl.parent
for delivering write completions; this switches all code paths to using
op->end_io.
Two reasons:
- op->end_io is more efficient, due to fewer atomic ops, this completes
the conversion that was originally only done for the direct IO path.
- We'll be restructing the write path to use a different mechanism for
punting to process context, refactoring to not use op->cl will make
that easier.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Buffered writes may have to increase their disk reservation at btree
update time, due to compression and erasure coding being unpredictable:
O_DIRECT writes should be checking for -ENOSPC, but buffered writes have
already been accepted and should not.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Writeback throttling is a kernel config option and not always enabled.
When it's not enabled we need a fallback, to avoid unbounded memory
pinning and work item backlogs.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Upcoming patch is going to disallow multiple btree_trans on the stack.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We keep running into occasional bugs with btree transaction iterators
overflowing - this will make those bugs more visible.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
An option was added to control whether reflink support was on or off
because for a long time, reflink + inline data extent support was
missing - but that's since been fixed, so we can drop the option now.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In the read path, for retry of indirect extents to work we need to
differentiate between the location in the btree the read was for, vs.
the location where we found the data. This patch adds that plumbing to
bch_read_bio.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This makes bch2_btree_iter_peek_prev() and bch2_btree_iter_prev()
consistent with peek() and next(), w.r.t. iter->pos.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We had a deadlock on page_lock, because buffered reads signal completion
by unlocking the page, but the dio read path normally dirties the pages
it's reading to with set_page_dirty_lock.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
With various newer key types - stripe keys, inline data extents - the
old approach of calculating the maximum size of the value is becoming
more and more error prone. Better to switch to bkey_on_stack, which can
dynamically allocate if necessary to handle any size bkey.
In particular we also want to get rid of BKEY_EXTENT_VAL_U64s_MAX.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Originally, we'd check for -ENOSPC when getting a disk reservation
whenever the new extent took up more space on disk than the old extent.
Erasure coding screwed this up, because with erasure coding writes are
initially replicated, and then in the background the extra replicas are
dropped when the stripe is created. This means that with erasure coding
enabled, writes will always take up more space on disk than the data
they're overwriting - but, according to posix, overwrites aren't
supposed to return ENOSPC.
So, in this patch we fudge things: if the new extent has more replicas
than the _effective_ replicas of the old extent, or if the old extent is
compressed and the new one isn't, we check for ENOSPC when getting the
disk reservation - otherwise, we don't.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
With the btree key cache code, we don't need to update the alloc btree
lazily - and this will mean we can remove the bch2_alloc_write() call in
the shutdown path.
Future work: we really need to expend the bucket IO clocks from 16 to 64
bits, so that we don't have to rescale them.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
On write error, the vfs inode's i_size may be inconsistent with the
btree inode's i_size - flag this so we don't have spurious assertions.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
it's useful to know whether an error was for a read or a write - this
also standardizes error messages a bit more.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Since we now always preallocate the maximum number of iterators when we
initialize a btree transaction, getting an iterator never fails - we can
delete a fair amount of error path code.
This patch also simplifies the iterator allocation code a bit.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We were incorrectly ignoring the return value of __readahead_batch,
leading to a null ptr deref in __bch2_page_state_create().
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In the dio write path, when get_user_pages() invokes the fault handler
we have a recursive locking situation - we have to handle the lock
ordering ourselves or we have a deadlock: this patch addresses that by
checking for locking ordering violations and doing the unlock/relock
dance if necessary.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
These recently added helpers simplify the code.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This is dead code; delete the function.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
If the bkey_on_stack_reassemble() call in __bch2_read_indirect_extent()
reallocates the buffer, k in bch2_read - which we pointed at the
bkey_on_stack buffer - will now point to a stale buffer. Whoops.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
__bch2_truncate_page() will mark some of the blocks in a page as
unallocated. But, if the page is mmapped (and writable), every block in
the page needs to be marked dirty, else those blocks won't be written by
__bch2_writepage().
The solution is to change those userspace mappings to RO, so that we
force bch2_page_mkwrite() to be called again.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In the buffered write path, we have to check for short writes that write
to the full page, where the page wasn't UpToDate; when this happens, the
page is partly garbage, so we have to zero it out and revert that part
of the write.
This check was wrong - we reverted total from copied, but didn't revert
the iov_iter, probably also leading to corrupted writes.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
It appears this was erronious, a different bug was responsible
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This fixes a bug where the BCH_WRITE_SKIP_CLOSURE_PUT was set
incorrectly, causing the completion to be delivered multiple times.
oops.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Reflink might be buggy, so we're adding an option so users can help
bisect what's going on.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
When a bkey_on_stack is passed to bch_read_indirect_extent, there is no
guarantee that it will be big enough to hold the bkey. And
bch_read_indirect_extent is not aware of bkey_on_stack to call realloc
on it. This cause a stack corruption.
This commit makes bch_read_indirect_extent aware of bkey_on_stack so it
can call realloc when appropriate.
Tested-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
the bcachefs io path in io.c can't bounce writes larger than that.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This was another bug because of bch2_btree_iter_set_pos() invalidating
iterators.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
All iterators should be released now with bch2_trans_iter_put(), so
TRANS_RESET_ITERS shouldn't be needed anymore, and TRANS_RESET_MEM is
always used.
Also convert more code to __bch2_trans_do().
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Previously, when doing multiple update in the same transaction commit
that overwrote each other, we relied on doing the updates in the same
order as the bch2_trans_update() calls in order to get the correct
result. But that wasn't correct for triggers; bch2_trans_mark_update()
when marking overwrites would do the wrong thing because it hadn't seen
the update that was being overwritten.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The trigger flags really belong with individual btree_insert_entries,
not the transaction commit flags - this splits out those flags and
unifies them with the BCH_BUCKET_MARK flags. Todo - split out
btree_trigger.c from buckets.c
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
BTREE_INSERT_ATOMIC should really be the default mode, and there's not
that much code that doesn't need it - so this is prep work for getting
rid of the flag.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
It needs to be called when we get -EINTR due to e.g. lock restart - this
fixes a transaction iterators overflow bug.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Normally the in memory i_size is always greater than or equal to i_size
on disk; this doesn't hold on filesystem error.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This implements extents that have their data inline, in the value,
instead of the bkey value being pointers to the data - and the read and
write paths are updated to read from these new extent types and write
them out, when the write size is small enough.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This changes bch2_cut_front and bch2_cut_back so that they're able to
shorten the size of the value, and it also changes the extent update
path to update the accounting in the btree node when this happens.
When the size of the value is shortened, they zero out the space that's
no longer used, so it's interpreted as noops (as implemented in the last
patch).
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This implements code for storing small bkeys on the stack and allocating
out of a mempool if they're too big.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
len might fit into a loff_t when aligned_len does not - make sure we use
a u64 for aligned_len. Also, we weren't always extending the inode
correctly.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We can assume that usually buffered and O_DIRECT IO won't be mixed, and
the calls to flush the page cache won't be needed.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In theory we should be able to do (non appending/extending) dio writes
without taking the inode lock at all - but this gets us most of the way
there.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This adds some horrible hacks, but the atomic ops for closures were
getting to be a pretty expensive part of the write path. We don't want
to rip out closures entirely from the write path, because they're used
for e.g. waiting on the allocator, or waiting on the journal flush, and
that stuff would get really ugly without closures.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
On IO error, bch2_writepages_io_done() will set the page state to
indicate nothing's already reserved (since the write didn't happen, we
don't know what's already reserved). This can race with the buffered IO
path, in between getting a disk reservation and calling
bch2_set_page_dirty().
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This works around a bug where bio_full() doesn't check for
bio->bi_iter.bi_size overflowing - and, we don't really want to build
bios that are that big anyways.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The generic IO path now handles inode updates for i_size and i_sectors -
this means we can drop a fair amount of code from fs-io.c.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The next few patches are going to be more moving the logic around
i_size/i_sectors updates to io.c, and better separating the Linux VFS
specific code from core bcachefs code, to better support the fuse port.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Moving bch2_extent_update() to io.c will be greatly simplified if we
no longer have to keep ei_inode.bi_size/bi_sectors up to date.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
In bch2_extent_update(), we have to update the inode if i_size is
changing (the file is being extend) or if i_sectors is changing, but we
want to avoid touching the inode if it's not necessary.
Change sum_sector_overwrites() to also check if there's already data
above where we're writing to - this means we're definitely not extending
the file.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We can't use the page lock to protect it, because on writeback IO error
we need to access the page state before calling end_page_writeback() and
the page lock semantics are completely insane so that deadlocks.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This fixes a bug in io.c bch2_write_index_default() - it was missing the
traverse call, but bch2_extent_atomic_end returns an error now and can
just call it itself.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
When grab_cache_page_write_begin() fails but we did pin some pages, we
shouldn't return -ENOMEM, we should do a partial write.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
The btree_trans struct needs to memoize/cache btree iterators, so that
on transaction restart we don't have to completely redo btree lookups,
and so that we can do them all at once in the correct order when the
transaction had to restart to avoid a deadlock.
This switches the btree iterator lookups to work based on iterator
position, instead of trying to match them up based on the stack trace.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
We shouldn't ever be writing past i_size - but, apparently there's still
a bug to track down.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
If the user buffer isn't aligned to the filesystem block size, on a
large enough IO - where it won't fit into a single bio -
bio_iov_iter_get_pages() won't necessarily return a bio with the proper
alignment.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Move extents instead of copying them - this way, we can iterate over
only live extents, not the entire keyspace. Also, this means we can
mostly skip running triggers.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
With reflink, various code now has to handle both KEY_TYPE_extent
or KEY_TYPE_reflink_v - so, convert it to be generic across all keys
with pointers.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Prep work for reflink - for reflink, we're going to be using
bch2_extent_update() with other updates in the same transaction.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
With reflink, we'll no longer be able to calculate the offset of the
data we want into the extent we're reading from from the extent pos and
the iter pos - we'll have to pass it in separately.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This will mean we don't have to use cmpxchg for modifying page state,
which will simplify a fair amount of code
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Switch to always using bio_add_page(), which merges contiguous pages now
that we have multipage bvecs.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
this lets us get rid of a lot of extra switch statements - in a lot of
places we dispatch on the btree node type, and then the key type, so
this is a nice cleanup across a lot of code.
Also improve the on disk format versioning stuff.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
previously, if the code traversed to the next btree node, that could
return an error (due to lock restarts) - which was not being checked
for.
fix is to rework it so it never iterates past the current leaf node, and
pops an assertion if it ever sees an error.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
ei_update_lock isn't currently needed for write inode (but it will be
needed again when deferred btree updates are used for inode updates)
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Initially forked from drivers/md/bcache, bcachefs is a new copy-on-write
filesystem with every feature you could possibly want.
Website: https://bcachefs.org
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
