linux/mm/folio-compat.c
Christoph Hellwig 66dabbb65d mm: return an ERR_PTR from __filemap_get_folio
Instead of returning NULL for all errors, distinguish between:

 - no entry found and not asked to allocated (-ENOENT)
 - failed to allocate memory (-ENOMEM)
 - would block (-EAGAIN)

so that callers don't have to guess the error based on the passed in
flags.

Also pass through the error through the direct callers: filemap_get_folio,
filemap_lock_folio filemap_grab_folio and filemap_get_incore_folio.

[hch@lst.de: fix null-pointer deref]
  Link: https://lkml.kernel.org/r/20230310070023.GA13563@lst.de
  Link: https://lkml.kernel.org/r/20230310043137.GA1624890@u2004
Link: https://lkml.kernel.org/r/20230307143410.28031-8-hch@lst.de
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Ryusuke Konishi <konishi.ryusuke@gmail.com> [nilfs2]
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-04-05 19:42:42 -07:00

137 lines
3.2 KiB
C

/*
* Compatibility functions which bloat the callers too much to make inline.
* All of the callers of these functions should be converted to use folios
* eventually.
*/
#include <linux/migrate.h>
#include <linux/pagemap.h>
#include <linux/rmap.h>
#include <linux/swap.h>
#include "internal.h"
struct address_space *page_mapping(struct page *page)
{
return folio_mapping(page_folio(page));
}
EXPORT_SYMBOL(page_mapping);
void unlock_page(struct page *page)
{
return folio_unlock(page_folio(page));
}
EXPORT_SYMBOL(unlock_page);
void end_page_writeback(struct page *page)
{
return folio_end_writeback(page_folio(page));
}
EXPORT_SYMBOL(end_page_writeback);
void wait_on_page_writeback(struct page *page)
{
return folio_wait_writeback(page_folio(page));
}
EXPORT_SYMBOL_GPL(wait_on_page_writeback);
void wait_for_stable_page(struct page *page)
{
return folio_wait_stable(page_folio(page));
}
EXPORT_SYMBOL_GPL(wait_for_stable_page);
void mark_page_accessed(struct page *page)
{
folio_mark_accessed(page_folio(page));
}
EXPORT_SYMBOL(mark_page_accessed);
bool set_page_writeback(struct page *page)
{
return folio_start_writeback(page_folio(page));
}
EXPORT_SYMBOL(set_page_writeback);
bool set_page_dirty(struct page *page)
{
return folio_mark_dirty(page_folio(page));
}
EXPORT_SYMBOL(set_page_dirty);
int __set_page_dirty_nobuffers(struct page *page)
{
return filemap_dirty_folio(page_mapping(page), page_folio(page));
}
EXPORT_SYMBOL(__set_page_dirty_nobuffers);
bool clear_page_dirty_for_io(struct page *page)
{
return folio_clear_dirty_for_io(page_folio(page));
}
EXPORT_SYMBOL(clear_page_dirty_for_io);
bool redirty_page_for_writepage(struct writeback_control *wbc,
struct page *page)
{
return folio_redirty_for_writepage(wbc, page_folio(page));
}
EXPORT_SYMBOL(redirty_page_for_writepage);
void lru_cache_add_inactive_or_unevictable(struct page *page,
struct vm_area_struct *vma)
{
folio_add_lru_vma(page_folio(page), vma);
}
int add_to_page_cache_lru(struct page *page, struct address_space *mapping,
pgoff_t index, gfp_t gfp)
{
return filemap_add_folio(mapping, page_folio(page), index, gfp);
}
EXPORT_SYMBOL(add_to_page_cache_lru);
noinline
struct page *pagecache_get_page(struct address_space *mapping, pgoff_t index,
int fgp_flags, gfp_t gfp)
{
struct folio *folio;
folio = __filemap_get_folio(mapping, index, fgp_flags, gfp);
if (IS_ERR(folio))
return NULL;
return folio_file_page(folio, index);
}
EXPORT_SYMBOL(pagecache_get_page);
struct page *grab_cache_page_write_begin(struct address_space *mapping,
pgoff_t index)
{
unsigned fgp_flags = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE;
return pagecache_get_page(mapping, index, fgp_flags,
mapping_gfp_mask(mapping));
}
EXPORT_SYMBOL(grab_cache_page_write_begin);
bool isolate_lru_page(struct page *page)
{
if (WARN_RATELIMIT(PageTail(page), "trying to isolate tail page"))
return false;
return folio_isolate_lru((struct folio *)page);
}
void putback_lru_page(struct page *page)
{
folio_putback_lru(page_folio(page));
}
#ifdef CONFIG_MMU
void page_add_new_anon_rmap(struct page *page, struct vm_area_struct *vma,
unsigned long address)
{
VM_BUG_ON_PAGE(PageTail(page), page);
return folio_add_new_anon_rmap((struct folio *)page, vma, address);
}
#endif