Commit 79c13745 authored by Xu Yang's avatar Xu Yang Committed by Christian Brauner
Browse files

filemap: add helper mapping_max_folio_size() 



Add mapping_max_folio_size() to get the maximum folio size for this
pagecache mapping.

Fixes: 5d8edfb9 ("iomap: Copy larger chunks from userspace")
Cc: stable@vger.kernel.org
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarXu Yang <xu.yang_2@nxp.com>
Link: https://lore.kernel.org/r/20240521114939.2541461-1-xu.yang_2@nxp.com


Reviewed-by: default avatarRitesh Harjani (IBM) <ritesh.list@gmail.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 2c6b5310

include/linux/pagemap.h

+21 −13
Original line number Diff line number Diff line
@@ -346,6 +346,19 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask) 
	m->gfp_mask = mask;

}



/*

 * There are some parts of the kernel which assume that PMD entries

 * are exactly HPAGE_PMD_ORDER.  Those should be fixed, but until then,

 * limit the maximum allocation order to PMD size.  I'm not aware of any

 * assumptions about maximum order if THP are disabled, but 8 seems like

 * a good order (that's 1MB if you're using 4kB pages)

 */

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

#define MAX_PAGECACHE_ORDER	HPAGE_PMD_ORDER

#else

#define MAX_PAGECACHE_ORDER	8

#endif



/**

 * mapping_set_large_folios() - Indicate the file supports large folios.

 * @mapping: The file.
@@ -372,6 +385,14 @@ static inline bool mapping_large_folio_support(struct address_space *mapping) 
		test_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags);

}



/* Return the maximum folio size for this pagecache mapping, in bytes. */

static inline size_t mapping_max_folio_size(struct address_space *mapping)

{

	if (mapping_large_folio_support(mapping))

		return PAGE_SIZE << MAX_PAGECACHE_ORDER;

	return PAGE_SIZE;

}



static inline int filemap_nr_thps(struct address_space *mapping)

{

#ifdef CONFIG_READ_ONLY_THP_FOR_FS
@@ -530,19 +551,6 @@ static inline void *detach_page_private(struct page *page) 
	return folio_detach_private(page_folio(page));

}



/*

 * There are some parts of the kernel which assume that PMD entries

 * are exactly HPAGE_PMD_ORDER.  Those should be fixed, but until then,

 * limit the maximum allocation order to PMD size.  I'm not aware of any

 * assumptions about maximum order if THP are disabled, but 8 seems like

 * a good order (that's 1MB if you're using 4kB pages)

 */

#ifdef CONFIG_TRANSPARENT_HUGEPAGE

#define MAX_PAGECACHE_ORDER	HPAGE_PMD_ORDER

#else

#define MAX_PAGECACHE_ORDER	8

#endif



#ifdef CONFIG_NUMA

struct folio *filemap_alloc_folio_noprof(gfp_t gfp, unsigned int order);

#else