Subject: [PATCH] exfat: use truncate_inode_pages_final() at evict_inode()

[PATCH] Subject: [PATCH] exfat: use truncate_inode_pages_final() at evict_inode()

Posted by Yang Wen 1 month, 1 week ago

Currently, exfat uses truncate_inode_pages() in exfat_evict_inode().
However, truncate_inode_pages() does not mark the mapping as exiting,
so reclaim may still install shadow entries for the mapping until
the inode teardown completes.

In older kernels like Linux 5.10, if shadow entries are present
at that point,clear_inode() can hit

    BUG_ON(inode->i_data.nrexceptional);

To align with VFS eviction semantics and prevent this situation,
switch to truncate_inode_pages_final() in ->evict_inode().

Other filesystems were updated to use truncate_inode_pages_final()
in ->evict_inode() by commit 91b0abe36a7b ("mm + fs: store shadow
entries in page cache")'.

Signed-off-by: Yang Wen <anmuxixixi@gmail.com>
---
 fs/exfat/inode.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/exfat/inode.c b/fs/exfat/inode.c
index 2fb2d2d5d503..567308aff726 100644
--- a/fs/exfat/inode.c
+++ b/fs/exfat/inode.c
@@ -686,7 +686,7 @@ struct inode *exfat_build_inode(struct super_block *sb,
 
 void exfat_evict_inode(struct inode *inode)
 {
-	truncate_inode_pages(&inode->i_data, 0);
+	truncate_inode_pages_final(&inode->i_data);
 
 	if (!inode->i_nlink) {
 		i_size_write(inode, 0);
-- 
2.43.0

Re: [PATCH] Subject: [PATCH] exfat: use truncate_inode_pages_final() at evict_inode()

Posted by Namjae Jeon 1 month, 1 week ago

On Wed, Feb 25, 2026 at 11:59 PM Yang Wen <anmuxixixi@gmail.com> wrote:
>
> Currently, exfat uses truncate_inode_pages() in exfat_evict_inode().
> However, truncate_inode_pages() does not mark the mapping as exiting,
> so reclaim may still install shadow entries for the mapping until
> the inode teardown completes.
>
> In older kernels like Linux 5.10, if shadow entries are present
> at that point,clear_inode() can hit
>
>     BUG_ON(inode->i_data.nrexceptional);
>
> To align with VFS eviction semantics and prevent this situation,
> switch to truncate_inode_pages_final() in ->evict_inode().
>
> Other filesystems were updated to use truncate_inode_pages_final()
> in ->evict_inode() by commit 91b0abe36a7b ("mm + fs: store shadow
> entries in page cache")'.
>
> Signed-off-by: Yang Wen <anmuxixixi@gmail.com>
Applied it to #dev.
Thanks!