[PATCH v9 1/8] writeback, cgroup: do not switch inodes with I_WILL_FREE flag
From: Roman Gushchin <hidden>
Date: 2021-06-08 23:05:02
Also in:
linux-fsdevel, linux-mm, lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
If an inode's state has I_WILL_FREE flag set, the inode will be freed soon, so there is no point in trying to switch the inode to a different cgwb. I_WILL_FREE was ignored since the introduction of the inode switching, so it looks like it doesn't lead to any noticeable issues for a user. This is why the patch is not intended for a stable backport. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Roman Gushchin <redacted> Acked-by: Tejun Heo <tj@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Acked-by: Dennis Zhou <dennis@kernel.org> --- fs/fs-writeback.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 7c46d1588a19..7d2891d7ac12 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c@@ -389,10 +389,10 @@ static void inode_switch_wbs_work_fn(struct work_struct *work) xa_lock_irq(&mapping->i_pages); /* - * Once I_FREEING is visible under i_lock, the eviction path owns - * the inode and we shouldn't modify ->i_io_list. + * Once I_FREEING or I_WILL_FREE are visible under i_lock, the eviction + * path owns the inode and we shouldn't modify ->i_io_list. */ - if (unlikely(inode->i_state & I_FREEING)) + if (unlikely(inode->i_state & (I_FREEING | I_WILL_FREE))) goto skip_switch; trace_inode_switch_wbs(inode, old_wb, new_wb);
@@ -517,7 +517,7 @@ static void inode_switch_wbs(struct inode *inode, int new_wb_id) /* while holding I_WB_SWITCH, no one else can update the association */ spin_lock(&inode->i_lock); if (!(inode->i_sb->s_flags & SB_ACTIVE) || - inode->i_state & (I_WB_SWITCH | I_FREEING) || + inode->i_state & (I_WB_SWITCH | I_FREEING | I_WILL_FREE) || inode_to_wb(inode) == isw->new_wb) { spin_unlock(&inode->i_lock); goto out_free;
--
2.31.1