nilfs2: fix buffer head leaks in calls to truncate_inode_pages()

When block_invalidatepage was converted to block_invalidate_folio, the
fallback to block_invalidatepage in folio_invalidate() if the
address_space_operations method invalidatepage (currently
invalidate_folio) was not set, was removed.

Unfortunately, some pseudo-inodes in nilfs2 use empty_aops set by
inode_init_always_gfp() as is, or explicitly set it to
address_space_operations.  Therefore, with this change,
block_invalidatepage() is no longer called from folio_invalidate(), and as
a result, the buffer_head structures attached to these pages/folios are no
longer freed via try_to_free_buffers().

Thus, these buffer heads are now leaked by truncate_inode_pages(), which
cleans up the page cache from inode evict(), etc.

Three types of caches use empty_aops: gc inode caches and the DAT shadow
inode used by GC, and b-tree node caches.  Of these, b-tree node caches
explicitly call invalidate_mapping_pages() during cleanup, which involves
calling try_to_free_buffers(), so the leak was not visible during normal
operation but worsened when GC was performed.

Fix this issue by using address_space_operations with invalidate_folio set
to block_invalidate_folio instead of empty_aops, which will ensure the
same behavior as before.

Link: https://lkml.kernel.org/r/20241212164556.21338-1-konishi.ryusuke@gmail.com
Fixes: 7ba13abbd31e ("fs: Turn block_invalidatepage into block_invalidate_folio")
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@gmail.com>
Cc: <stable@vger.kernel.org>	[5.18+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c
index 501ad7be5174cb4e810cde4ca3c062d2699a3dd9..54a3fa0cf67edbf9411a5b6b7f20c1d9ba163e05 100644 (file)
--- a/fs/nilfs2/btnode.c
+++ b/fs/nilfs2/btnode.c
@@ -35,6 +35,7 @@ void nilfs_init_btnc_inode(struct inode *btnc_inode)
        ii->i_flags = 0;
        memset(&ii->i_bmap_data, 0, sizeof(struct nilfs_bmap));
        mapping_set_gfp_mask(btnc_inode->i_mapping, GFP_NOFS);
+       btnc_inode->i_mapping->a_ops = &nilfs_buffer_cache_aops;
 }
 
 void nilfs_btnode_cache_clear(struct address_space *btnc)

diff --git a/fs/nilfs2/gcinode.c b/fs/nilfs2/gcinode.c
index ace22253fed0f2d1d5f17a3b07c8ee355c890a11..2dbb15767df16e552c76f4eeaf468fcb77490bdd 100644 (file)
--- a/fs/nilfs2/gcinode.c
+++ b/fs/nilfs2/gcinode.c
@@ -163,7 +163,7 @@ int nilfs_init_gcinode(struct inode *inode)
 
        inode->i_mode = S_IFREG;
        mapping_set_gfp_mask(inode->i_mapping, GFP_NOFS);
-       inode->i_mapping->a_ops = &empty_aops;
+       inode->i_mapping->a_ops = &nilfs_buffer_cache_aops;
 
        ii->i_flags = 0;
        nilfs_bmap_init_gc(ii->i_bmap);

diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c
index b7d4105f37bf5175f55eeea1fd161401d7ac7df0..23f3a75edd50164bdc53d3935a2d7eedf9a0dbe8 100644 (file)
--- a/fs/nilfs2/inode.c
+++ b/fs/nilfs2/inode.c
@@ -276,6 +276,10 @@ const struct address_space_operations nilfs_aops = {
        .is_partially_uptodate  = block_is_partially_uptodate,
 };
 
+const struct address_space_operations nilfs_buffer_cache_aops = {
+       .invalidate_folio       = block_invalidate_folio,
+};
+
 static int nilfs_insert_inode_locked(struct inode *inode,
                                     struct nilfs_root *root,
                                     unsigned long ino)
@@ -681,6 +685,7 @@ struct inode *nilfs_iget_for_shadow(struct inode *inode)
        NILFS_I(s_inode)->i_flags = 0;
        memset(NILFS_I(s_inode)->i_bmap, 0, sizeof(struct nilfs_bmap));
        mapping_set_gfp_mask(s_inode->i_mapping, GFP_NOFS);
+       s_inode->i_mapping->a_ops = &nilfs_buffer_cache_aops;
 
        err = nilfs_attach_btree_node_cache(s_inode);
        if (unlikely(err)) {

diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h
index 45d03826eaf157f3f74f5239f6d2ba094eec6282..dff241c53fc583d16478c58c1b3c80f80aed42b1 100644 (file)
--- a/fs/nilfs2/nilfs.h
+++ b/fs/nilfs2/nilfs.h
@@ -401,6 +401,7 @@ extern const struct file_operations nilfs_dir_operations;
 extern const struct inode_operations nilfs_file_inode_operations;
 extern const struct file_operations nilfs_file_operations;
 extern const struct address_space_operations nilfs_aops;
+extern const struct address_space_operations nilfs_buffer_cache_aops;
 extern const struct inode_operations nilfs_dir_inode_operations;
 extern const struct inode_operations nilfs_special_inode_operations;
 extern const struct inode_operations nilfs_symlink_inode_operations;