Commit Graph

206 Commits

Author SHA1 Message Date
Kent Overstreet
46bf2e9cc7 bcachefs: Fix excess transaction restarts in __bchfs_fallocate()
drop_locks_do() should not be used in a fastpath without first trying
the do in nonblocking mode - the unlock and relock will cause excessive
transaction restarts and potentially livelocking with other threads that
are contending for the same locks.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-21 13:27:10 -05:00
Kent Overstreet
0c99e17d3b bcachefs: growable btree_paths
XXX: we're allocating memory with btree locks held - bad

We need to plumb through an error path so we can do
allocate_dropping_locks() - but we're merging this now because it fixes
a transaction path overflow caused by indirect extent fragmentation, and
the resize path is rare.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:44 -05:00
Kent Overstreet
2c3b0fc3bd bcachefs: trans->nr_paths
Start to plumb through dynamically growable btree_paths; this patch
replaces most BTREE_ITER_MAX references with trans->nr_paths.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:44 -05:00
Kent Overstreet
fea153a845 bcachefs: rcu protect trans->paths
Upcoming patches are going to be changing trans->paths to a
reallocatable buffer. We need to guard against use after free when it's
used by other threads; this introduces RCU protection to those paths and
changes them to check for trans->paths == NULL

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:44 -05:00
Kent Overstreet
398c98347d bcachefs: kill btree_path.idx
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:44 -05:00
Kent Overstreet
b0b6737822 bcachefs: trans_for_each_path_with_node() no longer uses path->idx
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
ccb7b08fbb bcachefs: trans_for_each_path() no longer uses path->idx
path->idx is now a code smell: we should be using path_idx_t, since it's
stable across btree path reallocation.

This is also a bit faster, using the same loop counter vs. fetching
path->idx from each path we iterate over.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
4c5289e632 bcachefs: kill trans_for_each_path_from()
dead code

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
311e446a41 bcachefs: bch2_btree_path_to_text() -> btree_path_idx_t
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
1f75ba4e65 bcachefs: struct trans_for_each_path_inorder_iter
reducing our usage of path->idx

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
07f383c71f bcachefs: btree_iter -> btree_path_idx_t
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
96ed47d130 bcachefs: bch2_btree_path_traverse() -> btree_path_idx_t
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
f6363acaa6 bcachefs: bch2_btree_path_make_mut() -> btree_path_idx_t
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
4617d94617 bcachefs: bch2_btree_path_set_pos() -> btree_path_idx_t
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
74e600c19a bcachefs; bch2_path_put() -> btree_path_idx_t
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
255ebbbf75 bcachefs: bch2_path_get() -> btree_path_idx_t
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
5ce8b92da0 bcachefs: minor bch2_btree_path_set_pos() optimization
bpos_eq() is cheaper than bpos_cmp()

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
0bc64d7e26 bcachefs: kill __bch2_btree_iter_peek_upto_and_restart()
dead code

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:43 -05:00
Kent Overstreet
80eab7a7c2 bcachefs: for_each_btree_key() now declares loop iter
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:42 -05:00
Kent Overstreet
c47e8bfbb7 bcachefs: kill for_each_btree_key_norestart()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:42 -05:00
Kent Overstreet
44ddd8ad1e bcachefs: kill for_each_btree_key_old_upto()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:42 -05:00
Kent Overstreet
3a860b5ad5 bcachefs: for_each_btree_key_upto() -> for_each_btree_key_old_upto()
And for_each_btree_key2_upto -> for_each_btree_key_upto

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:42 -05:00
Kent Overstreet
79904fa2bb bcachefs: bch2_trans_srcu_lock() should be static
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:42 -05:00
Kent Overstreet
679972348d bcachefs: kill btree_trans->wb_updates
the btree write buffer path now creates a journal entry directly

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:41 -05:00
Kent Overstreet
f33600057f bcachefs: bch2_trans_node_add no longer uses trans_for_each_path()
In the future we'll be making trans->paths resizable and potentially
having _many_ more paths (for fsck); we need to start fixing algorithms
that walk each path in a transaction where possible.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:41 -05:00
Kent Overstreet
f8fd5871be bcachefs: reserve path idx 0 for sentinal
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:40 -05:00
Kent Overstreet
5028b9078c bcachefs: Rename for_each_btree_key2() -> for_each_btree_key()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:40 -05:00
Kent Overstreet
27b2df982f bcachefs: Kill for_each_btree_key()
for_each_btree_key() handles transaction restarts, like
for_each_btree_key2(), but only calls bch2_trans_begin() after a
transaction restart - for_each_btree_key2() wraps every loop iteration
in a transaction.

The for_each_btree_key() behaviour is problematic when it leads to
holding the SRCU lock that prevents key cache reclaim for an unbounded
amount of time - there's no real need to keep it around.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:40 -05:00
Kent Overstreet
8c066edeb4 bcachefs: continue now works in for_each_btree_key2()
continue now works as in any other loop

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:40 -05:00
Kent Overstreet
6e92d15546 bcachefs: Refactor trans->paths_allocated to be standard bitmap
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:40 -05:00
Kent Overstreet
e153a0d70b bcachefs: Improve trace_trans_restart_too_many_iters()
We now include the list of paths in use.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:39 -05:00
Kent Overstreet
ad9c7992eb bcachefs: Kill btree_iter->journal_pos
For BTREE_ITER_WITH_JOURNAL, we memoize lookups in the journal keys, to
avoid the binary search overhead.

Previously we stashed the pos of the last key returned from the journal,
in order to force the lookup to be redone when rewinding.

Now bch2_journal_keys_peek_upto() handles rewinding itself when
necessary - so we can slim down btree_iter.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:37 -05:00
Kent Overstreet
1ae8a0904a bcachefs: Kill memset() in bch2_btree_iter_init()
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:37 -05:00
Kent Overstreet
e56978c80d bcachefs: Kill BTREE_ITER_ALL_LEVELS
As discussed in the previous patch, BTREE_ITER_ALL_LEVELS appears to be
racy with concurrent interior node updates - and perhaps it is fixable,
but it's tricky and unnecessary.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2024-01-01 11:47:37 -05:00
Thomas Bertschinger
50a8a732d2 bcachefs: fix invalid memory access in bch2_fs_alloc() error path
When bch2_fs_alloc() gets an error before calling
bch2_fs_btree_iter_init(), bch2_fs_btree_iter_exit() makes an invalid
memory access because btree_trans_list is uninitialized.

Signed-off-by: Thomas Bertschinger <tahbertschinger@gmail.com>
Fixes: 6bd68ec266 ("bcachefs: Heap allocate btree_trans")
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-12-14 15:24:14 -05:00
Kent Overstreet
9fcdd23b6e bcachefs: Add a comment for BTREE_INSERT_NOJOURNAL usage
BTREE_INSERT_NOJOURNAL is primarily used for a performance optimization
related to inode updates and fsync - document it.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-11-04 22:19:13 -04:00
Kent Overstreet
d3c7727bb9 bcachefs: rebalance_work btree is not a snapshots btree
rebalance_work entries may refer to entries in the extents btree, which
is a snapshots btree, or they may also refer to entries in the reflink
btree, which is not.

Hence rebalance_work keys may use the snapshot field but it's not
required to be nonzero - add a new btree flag to reflect this.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-11-04 22:19:13 -04:00
Kent Overstreet
c4accde498 bcachefs: Ensure srcu lock is not held too long
The SRCU read lock that btree_trans takes exists to make it safe for
bch2_trans_relock() to deref pointers to btree nodes/key cache items we
don't have locked, but as a side effect it blocks reclaim from freeing
those items.

Thus, it's important to not hold it for too long: we need to
differentiate between bch2_trans_unlock() calls that will be only for a
short duration, and ones that will be for an unbounded duration.

This introduces bch2_trans_unlock_long(), to be used mainly by the data
move paths.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-11-04 14:17:11 -04:00
Kent Overstreet
50a38ca1ba bcachefs: Fix btree_node_type enum
More forwards compatibility fixups: having BKEY_TYPE_btree at the end of
the enum conflicts with unnkown btree IDs, this shifts BKEY_TYPE_btree
to slot 0 and fixes things up accordingly.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-31 12:18:37 -04:00
Kent Overstreet
6bd68ec266 bcachefs: Heap allocate btree_trans
We're using more stack than we'd like in a number of functions, and
btree_trans is the biggest object that we stack allocate.

But we have to do a heap allocatation to initialize it anyways, so
there's no real downside to heap allocating the entire thing.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:13 -04:00
Kent Overstreet
96dea3d599 bcachefs: Fix W=12 build errors
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:13 -04:00
Kent Overstreet
c872afa224 bcachefs: Fix bch2_propagate_key_to_snapshot_leaves()
When we handle a transaction restart in a nested context, we need to
return -BCH_ERR_transaction_restart_nested because we invalidated the
outer context's iterators and locks.

bch2_propagate_key_to_snapshot_leaves() wasn't doing this, this patch
fixes it to use trans_was_restarted().

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:12 -04:00
Kent Overstreet
8079aab085 bcachefs: Split up btree_update_leaf.c
We now have
  btree_trans_commit.c
  btree_update.c

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:10 -04:00
Kent Overstreet
f26c67f4a7 bcachefs: Snapshot depth, skiplist fields
This extents KEY_TYPE_snapshot to include some new fields:
 - depth, to indicate depth of this particular node from the root
 - skip[3], skiplist entries for quickly walking back up to the root

These are to improve bch2_snapshot_is_ancestor(), making it O(ln(n))
instead of O(n) in the snapshot tree depth.

Skiplist nodes are picked at random from the set of ancestor nodes, not
some fixed fraction.

This introduces bcachefs_metadata_version 1.1, snapshot_skiplists.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:06 -04:00
Kent Overstreet
73bd774d28 bcachefs: Assorted sparse fixes
- endianness fixes
 - mark some things static
 - fix a few __percpu annotations
 - fix silent enum conversions

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:06 -04:00
Kent Overstreet
9473cff989 bcachefs: Fix more lockdep splats in debug.c
Similar to previous fixes, we can't incur page faults while holding
btree locks.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:04 -04:00
Kent Overstreet
d95dd378c2 bcachefs: allocate_dropping_locks()
Add two new helpers for allocating memory with btree locks held: The
idea is to first try the allocation with GFP_NOWAIT|__GFP_NOWARN, then
if that fails - unlock, retry with GFP_KERNEL, and then call
trans_relock().

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:03 -04:00
Kent Overstreet
b5fd75669a bcachefs: drop_locks_do()
Add a new helper for the common pattern of:
 - trans_unlock()
 - do something
 - trans_relock()

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:03 -04:00
Kent Overstreet
e47a390aa5 bcachefs: Convert -ENOENT to private error codes
As with previous conversions, replace -ENOENT uses with more informative
private error codes.

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:03 -04:00
Kent Overstreet
f154c3eb42 bcachefs: trans_for_each_path_safe()
bch2_btree_trans_to_text() is used on btree_trans objects that are owned
by different threads - when printing out deadlock cycles - so we need a
safe version of trans_for_each_path(), else we race with seeing a
btree_path that was just allocated and not fully initialized:

Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2023-10-22 17:10:02 -04:00