[PATCH v3] fs: push list presence check into inode_io_list_del()

[Mateusz Guzik <mjguzik@gmail.com>]

For consistency with sb routines.

ext4 is the only consumer outside of evict(). Damage-controlling it is
outside of the scope of this cleanup.

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
---

v3:
- address feedback by Jan: take care of ext4

if you don't like the specific comment added below I would appreciate if
you adjusted it yourself.

this patch replaces this guy: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git/commit/?h=vfs-6.19.inode&id=7ba2ca3d17bb69276de7c97587b1e1f3d989f389

the other patch in the previous series remains unchanged

 fs/ext4/inode.c   | 3 +--
 fs/fs-writeback.c | 7 +++++++
 fs/inode.c        | 4 +---
 3 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index b864e9645f85..bf978ece70b3 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -202,8 +202,7 @@ void ext4_evict_inode(struct inode *inode)
 	 * the inode. Flush worker is ignoring it because of I_FREEING flag but
 	 * we still need to remove the inode from the writeback lists.
 	 */
-	if (!list_empty_careful(&inode->i_io_list))
-		inode_io_list_del(inode);
+	inode_io_list_del(inode);
 
 	/*
 	 * Protect us against freezing - iput() caller didn't have to have any
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index f784d8b09b04..e2eed66aabf8 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -1349,6 +1349,13 @@ void inode_io_list_del(struct inode *inode)
 {
 	struct bdi_writeback *wb;
 
+	/*
+	 * FIXME: ext4 can call here from ext4_evict_inode() after evict() already
+	 * unlinked the inode.
+	 */
+	if (list_empty_careful(&inode->i_io_list))
+		return;
+
 	wb = inode_to_wb_and_lock_list(inode);
 	spin_lock(&inode->i_lock);
 
diff --git a/fs/inode.c b/fs/inode.c
index 0f3a56ea8f48..263da76ed4fc 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -815,9 +815,7 @@ static void evict(struct inode *inode)
 	BUG_ON(!(inode_state_read_once(inode) & I_FREEING));
 	BUG_ON(!list_empty(&inode->i_lru));
 
-	if (!list_empty(&inode->i_io_list))
-		inode_io_list_del(inode);
-
+	inode_io_list_del(inode);
 	inode_sb_list_del(inode);
 
 	spin_lock(&inode->i_lock);
-- 
2.34.1