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>
This commit is contained in:
Matthew Wilcox (Oracle) 2022-05-01 07:35:31 -04:00
parent 6439476311
commit d2329aa0c7
5 changed files with 22 additions and 10 deletions

View File

@ -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

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@ -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

View File

@ -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);
/*

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@ -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);

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@ -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);
}