[PATCH 20/41] fs: Ignore inode metadata buffers in inode_lru_isolate()

Jan Kara
2026-03-20T13:42:57Z

There are only a few filesystems that use generic tracking of inode
metadata buffer heads. As such it is mostly pointless to verify such
attached buffer heads during inode reclaim. Drop the handling from
inode_lru_isolate().

Signed-off-by: Jan Kara <jack@suse.cz>
---
fs/buffer.c | 29 -----------------------------
fs/inode.c | 21 +++++++++------------
include/linux/buffer_head.h | 3 ---
3 files changed, 9 insertions(+), 44 deletions(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index 1bc0f22f3cc2..bd48644e1bf8 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -878,35 +878,6 @@ void invalidate_inode_buffers(struct inode *inode)
}
EXPORT_SYMBOL(invalidate_inode_buffers);

-/*
- * Remove any clean buffers from the inode's buffer list. This is called
- * when we're trying to free the inode itself. Those buffers can pin it.
- *
- * Returns true if all buffers were removed.
- */
-int remove_inode_buffers(struct inode *inode)
-{
- int ret = 1;
-
- if (inode_has_buffers(inode)) {
- struct address_space *mapping = &inode->i_data;
- struct list_head *list = &mapping->i_private_list;
- struct address_space *buffer_mapping = mapping->i_private_data;
-
- spin_lock(&buffer_mapping->i_private_lock);
- while (!list_empty(list)) {
- struct buffer_head *bh = BH_ENTRY(list->next);
- if (buffer_dirty(bh)) {
- ret = 0;
- break;
- }
- __remove_assoc_queue(bh);
- }
- spin_unlock(&buffer_mapping->i_private_lock);
- }
- return ret;
-}
-
/*
* Create the appropriate buffers when given a folio for data area and
* the size of each buffer.. Use the bh->b_this_page linked list to
diff --git a/fs/inode.c b/fs/inode.c
index cc12b68e021b..4f98a5f04bbd 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -17,7 +17,6 @@
#include <linux/fsverity.h>
#include <linux/mount.h>
#include <linux/posix_acl.h>
-#include <linux/buffer_head.h> /* for inode_has_buffers */
#include <linux/ratelimit.h>
#include <linux/list_lru.h>
#include <linux/iversion.h>
@@ -367,7 +366,6 @@ struct inode *alloc_inode(struct super_block *sb)

void __destroy_inode(struct inode *inode)
{
- BUG_ON(inode_has_buffers(inode));
inode_detach_wb(inode);
security_inode_free(inode);
fsnotify_inode_delete(inode);
@@ -994,19 +992,18 @@ static enum lru_status inode_lru_isolate(struct list_head *item,
* page cache in order to free up struct inodes: lowmem might
* be under pressure before the cache inside the highmem zone.
*/
- if (inode_has_buffers(inode) || !mapping_empty(&inode->i_data)) {
+ if (!mapping_empty(&inode->i_data)) {
+ unsigned long reap;
+
inode_pin_lru_isolating(inode);
spin_unlock(&inode->i_lock);
spin_unlock(&lru->lock);
- if (remove_inode_buffers(inode)) {
- unsigned long reap;
- reap = invalidate_mapping_pages(&inode->i_data, 0, -1);
- if (current_is_kswapd())
- __count_vm_events(KSWAPD_INODESTEAL, reap);
- else
- __count_vm_events(PGINODESTEAL, reap);
- mm_account_reclaimed_pages(reap);
- }
+ reap = invalidate_mapping_pages(&inode->i_data, 0, -1);
+ if (current_is_kswapd())
+ __count_vm_events(KSWAPD_INODESTEAL, reap);
+ else
+ __count_vm_events(PGINODESTEAL, reap);
+ mm_account_reclaimed_pages(reap);
inode_unpin_lru_isolating(inode);
return LRU_RETRY;
}
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h
index b16b88bfbc3e..631bf971efc0 100644
--- a/include/linux/buffer_head.h
+++ b/include/linux/buffer_head.h
@@ -517,7 +517,6 @@ void buffer_init(void);
bool try_to_free_buffers(struct folio *folio);
int inode_has_buffers(struct inode *inode);
void invalidate_inode_buffers(struct inode *inode);
-int remove_inode_buffers(struct inode *inode);
int sync_mapping_buffers(struct address_space *mapping);
void invalidate_bh_lrus(void);
void invalidate_bh_lrus_cpu(void);
@@ -528,9 +527,7 @@ extern int buffer_heads_over_limit;

static inline void buffer_init(void) {}
static inline bool try_to_free_buffers(struct folio *folio) { return true; }
-static inline int inode_has_buffers(struct inode *inode) { return 0; }
static inline void invalidate_inode_buffers(struct inode *inode) {}
-static inline int remove_inode_buffers(struct inode *inode) { return 1; }
static inline int sync_mapping_buffers(struct address_space *mapping) { return 0; }
static inline void invalidate_bh_lrus(void) {}
static inline void invalidate_bh_lrus_cpu(void) {}
--
2.51.0