From: Josef Bacik <josef@toxicpanda.com>
To: linux-btrfs@vger.kernel.org, kernel-team@fb.com
Subject: [PATCH 06/12] btrfs: introduce BTRFS_NESTING_LEFT/RIGHT_COW
Date: Thu, 20 Aug 2020 11:46:05 -0400 [thread overview]
Message-ID: <a228e8b88622403f98fcb46d5e7d4a4746192483.1597938191.git.josef@toxicpanda.com> (raw)
In-Reply-To: <cover.1597938190.git.josef@toxicpanda.com>
For similar reasons as BTRFS_NESTING_COW, we need
BTRFS_NESTING_LEFT/RIGHT_COW. The pattern is this
lock leaf -> BTRFS_NESTING_NORMAL
cow leaf -> BTRFS_NESTING_COW
split leaf
lock left -> BTRFS_NESTING_LEFT
cow left -> BTRFS_NESTING_LEFT_COW
We need this in order to indicate to lockdep that these locks are
discrete and are being taken in a safe order.
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
fs/btrfs/ctree.c | 12 ++++++------
fs/btrfs/locking.h | 8 ++++++++
2 files changed, 14 insertions(+), 6 deletions(-)
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index a4b2439a398a..ae5e3f1056d8 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1900,7 +1900,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
btrfs_set_lock_blocking_write(left);
wret = btrfs_cow_block(trans, root, left,
parent, pslot - 1, &left,
- BTRFS_NESTING_COW);
+ BTRFS_NESTING_LEFT_COW);
if (wret) {
ret = wret;
goto enospc;
@@ -1916,7 +1916,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
btrfs_set_lock_blocking_write(right);
wret = btrfs_cow_block(trans, root, right,
parent, pslot + 1, &right,
- BTRFS_NESTING_COW);
+ BTRFS_NESTING_RIGHT_COW);
if (wret) {
ret = wret;
goto enospc;
@@ -2085,7 +2085,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
} else {
ret = btrfs_cow_block(trans, root, left, parent,
pslot - 1, &left,
- BTRFS_NESTING_COW);
+ BTRFS_NESTING_LEFT_COW);
if (ret)
wret = 1;
else {
@@ -2140,7 +2140,7 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans,
} else {
ret = btrfs_cow_block(trans, root, right,
parent, pslot + 1,
- &right, BTRFS_NESTING_COW);
+ &right, BTRFS_NESTING_RIGHT_COW);
if (ret)
wret = 1;
else {
@@ -3751,7 +3751,7 @@ static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root
/* cow and double check */
ret = btrfs_cow_block(trans, root, right, upper,
- slot + 1, &right, BTRFS_NESTING_COW);
+ slot + 1, &right, BTRFS_NESTING_RIGHT_COW);
if (ret)
goto out_unlock;
@@ -3987,7 +3987,7 @@ static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root
/* cow and double check */
ret = btrfs_cow_block(trans, root, left,
path->nodes[1], slot - 1, &left,
- BTRFS_NESTING_COW);
+ BTRFS_NESTING_LEFT_COW);
if (ret) {
/* we hit -ENOSPC, but it isn't fatal here */
if (ret == -ENOSPC)
diff --git a/fs/btrfs/locking.h b/fs/btrfs/locking.h
index 3169c2bb6db9..a88c6f59f616 100644
--- a/fs/btrfs/locking.h
+++ b/fs/btrfs/locking.h
@@ -39,6 +39,14 @@ enum btrfs_lock_nesting {
BTRFS_NESTING_LEFT,
BTRFS_NESTING_RIGHT,
+ /*
+ * When splitting we will be holding a lock on the left/right node when
+ * we need to cow that node, thus we need a new set of subclasses for
+ * these two operations.
+ */
+ BTRFS_NESTING_LEFT_COW,
+ BTRFS_NESTING_RIGHT_COW,
+
/*
* We are limited to MAX_LOCKDEP_SUBLCLASSES number of subclasses, so
* add this in here and add a static_assert to keep us from going over
--
2.24.1
next prev parent reply other threads:[~2020-08-20 15:46 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-20 15:45 [PATCH 00/12] Convert btree locking to an rwsem Josef Bacik
2020-08-20 15:46 ` [PATCH 01/12] btrfs: rename eb->lock_nested to eb->lock_recursed Josef Bacik
2020-08-20 15:46 ` [PATCH 02/12] btrfs: introduce path->recurse Josef Bacik
2020-08-20 15:46 ` [PATCH 03/12] btrfs: add nesting tags to the locking helpers Josef Bacik
2020-08-20 15:46 ` [PATCH 04/12] btrfs: introduce BTRFS_NESTING_COW for cow'ing blocks Josef Bacik
2020-08-20 15:46 ` [PATCH 05/12] btrfs: introduce BTRFS_NESTING_LEFT/BTRFS_NESTING_RIGHT Josef Bacik
2020-08-20 15:46 ` Josef Bacik [this message]
2020-08-20 15:46 ` [PATCH 07/12] btrfs: introduce BTRFS_NESTING_SPLIT for split blocks Josef Bacik
2020-08-20 15:46 ` [PATCH 08/12] btrfs: introduce BTRFS_NESTING_NEW_ROOT for adding new roots Josef Bacik
2020-08-20 15:46 ` [PATCH 09/12] btrfs: use BTRFS_NESTED_NEW_ROOT for double splits Josef Bacik
2020-08-20 15:46 ` [PATCH 10/12] btrfs: change our extent buffer lock to a rw_semaphore Josef Bacik
2020-08-20 15:46 ` [PATCH 11/12] btrfs: remove all of the blocking helpers Josef Bacik
2020-08-20 15:46 ` [PATCH 12/12] btrfs: rip out path->leave_spinning Josef Bacik
2020-08-26 14:58 ` [PATCH 00/12] Convert btree locking to an rwsem David Sterba
2020-08-31 22:41 ` David Sterba
2020-11-03 20:59 ` David Sterba
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