fs: Add free_folio address space operation

Include documentation and convert the callers to use ->free_folio as
well as ->freepage.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

diff --git a/Documentation/filesystems/locking.rst b/Documentation/filesystems/locking.rst
index ddef4a753e73127903e317ae45a33afd6a82366d..515bc48ab58b450db902adf3401b72682b0ad548 100644 (file)
--- a/Documentation/filesystems/locking.rst
+++ b/Documentation/filesystems/locking.rst
@@ -250,7 +250,7 @@ prototypes::
        sector_t (*bmap)(struct address_space *, sector_t);
        void (*invalidate_folio) (struct folio *, size_t start, size_t len);
        bool (*release_folio)(struct folio *, gfp_t);
-       void (*freepage)(struct page *);
+       void (*free_folio)(struct folio *);
        int (*direct_IO)(struct kiocb *, struct iov_iter *iter);
        bool (*isolate_page) (struct page *, isolate_mode_t);
        int (*migratepage)(struct address_space *, struct page *, struct page *);
@@ -262,10 +262,10 @@ prototypes::
        int (*swap_deactivate)(struct file *);
 
 locking rules:
-       All except dirty_folio and freepage may block
+       All except dirty_folio and free_folio may block
 
 ====================== ======================== =========      ===============
-ops                    PageLocked(page)         i_rwsem        invalidate_lock
+ops                    folio locked             i_rwsem        invalidate_lock
 ====================== ======================== =========      ===============
 writepage:             yes, unlocks (see below)
 read_folio:            yes, unlocks                            shared
@@ -277,7 +277,7 @@ write_end:          yes, unlocks             exclusive
 bmap:
 invalidate_folio:      yes                                     exclusive
 release_folio:         yes
-freepage:              yes
+free_folio:            yes
 direct_IO:
 isolate_page:          yes
 migratepage:           yes (both)
@@ -377,7 +377,7 @@ buffers from the folio in preparation for freeing it.  It returns false to
 indicate that the buffers are (or may be) freeable.  If ->release_folio is
 NULL, the kernel assumes that the fs has no private interest in the buffers.
 
-->freepage() is called when the kernel is done dropping the page
+->free_folio() is called when the kernel has dropped the folio
 from the page cache.
 
 ->launder_folio() may be called prior to releasing a folio if

diff --git a/Documentation/filesystems/vfs.rst b/Documentation/filesystems/vfs.rst
index 679887b5c8fcfe66aa7d8ee49cebe6054f799543..12a011d2cbc6b3a1694baa06ebf400777b1c170f 100644 (file)
--- a/Documentation/filesystems/vfs.rst
+++ b/Documentation/filesystems/vfs.rst
@@ -735,7 +735,7 @@ cache in your filesystem.  The following members are defined:
                sector_t (*bmap)(struct address_space *, sector_t);
                void (*invalidate_folio) (struct folio *, size_t start, size_t len);
                bool (*release_folio)(struct folio *, gfp_t);
-               void (*freepage)(struct page *);
+               void (*free_folio)(struct folio *);
                ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter);
                /* isolate a page for migration */
                bool (*isolate_page) (struct page *, isolate_mode_t);
@@ -891,8 +891,8 @@ cache in your filesystem.  The following members are defined:
        its release_folio will need to ensure this.  Possibly it can
        clear the uptodate flag if it cannot free private data yet.
 
-``freepage``
-       freepage is called once the page is no longer visible in the
+``free_folio``
+       free_folio is called once the folio is no longer visible in the
        page cache in order to allow the cleanup of any private data.
        Since it may be called by the memory reclaimer, it should not
        assume that the original address_space mapping still exists, and

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 1cee64d9724b11ebb255ddc84f8ebd10ac10a959..915844e6293e6b9f130f358ad0b8949e3805d0e3 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -356,6 +356,7 @@ struct address_space_operations {
        sector_t (*bmap)(struct address_space *, sector_t);
        void (*invalidate_folio) (struct folio *, size_t offset, size_t len);
        bool (*release_folio)(struct folio *, gfp_t);
+       void (*free_folio)(struct folio *folio);
        void (*freepage)(struct page *);
        ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter);
        /*

diff --git a/mm/filemap.c b/mm/filemap.c
index d335a154a0d960685d9d6e2353f3e32df6e9d927..adcdef56890f14ddc7759a561d953ca8696ebc71 100644 (file)
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -226,8 +226,12 @@ void __filemap_remove_folio(struct folio *folio, void *shadow)
 void filemap_free_folio(struct address_space *mapping, struct folio *folio)
 {
        void (*freepage)(struct page *);
+       void (*free_folio)(struct folio *);
        int refs = 1;
 
+       free_folio = mapping->a_ops->free_folio;
+       if (free_folio)
+               free_folio(folio);
        freepage = mapping->a_ops->freepage;
        if (freepage)
                freepage(&folio->page);
@@ -807,6 +811,7 @@ void replace_page_cache_page(struct page *old, struct page *new)
        struct folio *fold = page_folio(old);
        struct folio *fnew = page_folio(new);
        struct address_space *mapping = old->mapping;
+       void (*free_folio)(struct folio *) = mapping->a_ops->free_folio;
        void (*freepage)(struct page *) = mapping->a_ops->freepage;
        pgoff_t offset = old->index;
        XA_STATE(xas, &mapping->i_pages, offset);
@@ -835,9 +840,11 @@ void replace_page_cache_page(struct page *old, struct page *new)
        if (PageSwapBacked(new))
                __inc_lruvec_page_state(new, NR_SHMEM);
        xas_unlock_irq(&xas);
+       if (free_folio)
+               free_folio(fold);
        if (freepage)
                freepage(old);
-       put_page(old);
+       folio_put(fold);
 }
 EXPORT_SYMBOL_GPL(replace_page_cache_page);
 

diff --git a/mm/vmscan.c b/mm/vmscan.c
index f3f7ce2c4068c859af9590ac8c41bb3b69828e81..d8a031128ad07a83d3cb87c2113ec9074fbea535 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1282,8 +1282,10 @@ static int __remove_mapping(struct address_space *mapping, struct folio *folio,
                xa_unlock_irq(&mapping->i_pages);
                put_swap_page(&folio->page, swap);
        } else {
+               void (*free_folio)(struct folio *);
                void (*freepage)(struct page *);
 
+               free_folio = mapping->a_ops->free_folio;
                freepage = mapping->a_ops->freepage;
                /*
                 * Remember a shadow entry for reclaimed file cache in
@@ -1310,7 +1312,9 @@ static int __remove_mapping(struct address_space *mapping, struct folio *folio,
                        inode_add_lru(mapping->host);
                spin_unlock(&mapping->host->i_lock);
 
-               if (freepage != NULL)
+               if (free_folio)
+                       free_folio(folio);
+               if (freepage)
                        freepage(&folio->page);
        }