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fs: spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb

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The incomming helpers don't ship with _release/_acquire variants, for
the time being anyway.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Mateusz Guzik
2025-10-09 09:59:16 +02:00
committed by Christian Brauner
parent af6023e2ce
commit cb5db358ab
2 changed files with 6 additions and 4 deletions
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fs/fs-writeback.c
+3 -2
View File
@@ -476,10 +476,11 @@ static bool inode_do_switch_wbs(struct inode *inode,
switched = true;
skip_switch:
/*
* Paired with load_acquire in unlocked_inode_to_wb_begin() and
* Paired with an acquire fence in unlocked_inode_to_wb_begin() and
* ensures that the new wb is visible if they see !I_WB_SWITCH.
*/
smp_store_release(&inode->i_state, inode->i_state & ~I_WB_SWITCH);
smp_wmb();
inode->i_state &= ~I_WB_SWITCH;
xa_unlock_irq(&mapping->i_pages);
spin_unlock(&inode->i_lock);
include/linux/backing-dev.h
+3 -2
View File
@@ -277,10 +277,11 @@ unlocked_inode_to_wb_begin(struct inode *inode, struct wb_lock_cookie *cookie)
rcu_read_lock();
/*
* Paired with store_release in inode_switch_wbs_work_fn() and
* Paired with a release fence in inode_do_switch_wbs() and
* ensures that we see the new wb if we see cleared I_WB_SWITCH.
*/
cookie->locked = smp_load_acquire(&inode->i_state) & I_WB_SWITCH;
cookie->locked = inode->i_state & I_WB_SWITCH;
smp_rmb();
if (unlikely(cookie->locked))
xa_lock_irqsave(&inode->i_mapping->i_pages, cookie->flags);