From: "Matthew Wilcox (Oracle)" willy@infradead.org
mainline inclusion from mainline-v6.10-rc2 commit 84429b675bcfd2a518ae167ee4661cdf7539aa7d category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/IBC20Q
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
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We need filesystems to be able to communicate acceptable folio sizes to the pagecache for a variety of uses (e.g. large block sizes). Support a range of folio sizes between order-0 and order-31.
Signed-off-by: Matthew Wilcox (Oracle) willy@infradead.org Co-developed-by: Pankaj Raghav p.raghav@samsung.com Signed-off-by: Pankaj Raghav p.raghav@samsung.com Link: https://lore.kernel.org/r/20240822135018.1931258-2-kernel@pankajraghav.com Tested-by: David Howells dhowells@redhat.com Reviewed-by: Hannes Reinecke hare@suse.de Reviewed-by: Darrick J. Wong djwong@kernel.org Reviewed-by: Daniel Gomez da.gomez@samsung.com Signed-off-by: Christian Brauner brauner@kernel.org Conflicts: include/linux/pagemap.h mm/filemap.c [Conflicts due to not merged 83ee0e20fd9f ("filemap: support disable large folios on active inode")] Signed-off-by: Long Li leo.lilong@huawei.com --- include/linux/pagemap.h | 90 +++++++++++++++++++++++++++++++++++------ mm/readahead.c | 4 +- 2 files changed, 79 insertions(+), 15 deletions(-)
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 429627abfef4..e44e377661f2 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -203,12 +203,21 @@ enum mapping_flags { AS_EXITING = 4, /* final truncate in progress */ /* writeback related tags are not used */ AS_NO_WRITEBACK_TAGS = 5, - AS_LARGE_FOLIO_SUPPORT = 6, - AS_RELEASE_ALWAYS, /* Call ->release_folio(), even if no private data */ - AS_STABLE_WRITES, /* must wait for writeback before modifying + AS_RELEASE_ALWAYS = 6, /* Call ->release_folio(), even if no private data */ + AS_STABLE_WRITES = 7, /* must wait for writeback before modifying folio contents */ + AS_INACCESSIBLE = 8, /* Do not attempt direct R/W access to the mapping */ + /* Bits 16-25 are used for FOLIO_ORDER */ + AS_FOLIO_ORDER_BITS = 5, + AS_FOLIO_ORDER_MIN = 16, + AS_FOLIO_ORDER_MAX = AS_FOLIO_ORDER_MIN + AS_FOLIO_ORDER_BITS, };
+#define AS_FOLIO_ORDER_BITS_MASK ((1u << AS_FOLIO_ORDER_BITS) - 1) +#define AS_FOLIO_ORDER_MIN_MASK (AS_FOLIO_ORDER_BITS_MASK << AS_FOLIO_ORDER_MIN) +#define AS_FOLIO_ORDER_MAX_MASK (AS_FOLIO_ORDER_BITS_MASK << AS_FOLIO_ORDER_MAX) +#define AS_FOLIO_ORDER_MASK (AS_FOLIO_ORDER_MIN_MASK | AS_FOLIO_ORDER_MAX_MASK) + /** * mapping_set_error - record a writeback error in the address_space * @mapping: the mapping in which an error should be set @@ -348,9 +357,51 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask) #define MAX_XAS_ORDER (XA_CHUNK_SHIFT * 2 - 1) #define MAX_PAGECACHE_ORDER min(MAX_XAS_ORDER, PREFERRED_MAX_PAGECACHE_ORDER)
+/* + * mapping_set_folio_order_range() - Set the orders supported by a file. + * @mapping: The address space of the file. + * @min: Minimum folio order (between 0-MAX_PAGECACHE_ORDER inclusive). + * @max: Maximum folio order (between @min-MAX_PAGECACHE_ORDER inclusive). + * + * The filesystem should call this function in its inode constructor to + * indicate which base size (min) and maximum size (max) of folio the VFS + * can use to cache the contents of the file. This should only be used + * if the filesystem needs special handling of folio sizes (ie there is + * something the core cannot know). + * Do not tune it based on, eg, i_size. + * + * Context: This should not be called while the inode is active as it + * is non-atomic. + */ +static inline void mapping_set_folio_order_range(struct address_space *mapping, + unsigned int min, + unsigned int max) +{ + if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) + return; + + if (min > MAX_PAGECACHE_ORDER) + min = MAX_PAGECACHE_ORDER; + + if (max > MAX_PAGECACHE_ORDER) + max = MAX_PAGECACHE_ORDER; + + if (max < min) + max = min; + + mapping->flags = (mapping->flags & ~AS_FOLIO_ORDER_MASK) | + (min << AS_FOLIO_ORDER_MIN) | (max << AS_FOLIO_ORDER_MAX); +} + +static inline void mapping_set_folio_min_order(struct address_space *mapping, + unsigned int min) +{ + mapping_set_folio_order_range(mapping, min, MAX_PAGECACHE_ORDER); +} + /** * mapping_set_large_folios() - Indicate the file supports large folios. - * @mapping: The file. + * @mapping: The address space of the file. * * The filesystem should call this function in its inode constructor to * indicate that the VFS can use large folios to cache the contents of @@ -361,7 +412,23 @@ static inline void mapping_set_gfp_mask(struct address_space *m, gfp_t mask) */ static inline void mapping_set_large_folios(struct address_space *mapping) { - __set_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags); + mapping_set_folio_order_range(mapping, 0, MAX_PAGECACHE_ORDER); +} + +static inline unsigned int +mapping_max_folio_order(const struct address_space *mapping) +{ + if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) + return 0; + return (mapping->flags & AS_FOLIO_ORDER_MAX_MASK) >> AS_FOLIO_ORDER_MAX; +} + +static inline unsigned int +mapping_min_folio_order(const struct address_space *mapping) +{ + if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) + return 0; + return (mapping->flags & AS_FOLIO_ORDER_MIN_MASK) >> AS_FOLIO_ORDER_MIN; }
/** @@ -375,7 +442,7 @@ static inline void mapping_set_large_folios(struct address_space *mapping) static inline void mapping_clear_large_folios(struct address_space *mapping) { WARN_ON_ONCE(!rwsem_is_locked(&mapping->invalidate_lock)); - __clear_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags); + mapping_set_folio_order_range(mapping, 0, 0); }
/* @@ -384,20 +451,17 @@ static inline void mapping_clear_large_folios(struct address_space *mapping) */ static inline bool mapping_large_folio_support(struct address_space *mapping) { - /* AS_LARGE_FOLIO_SUPPORT is only reasonable for pagecache folios */ + /* AS_FOLIO_ORDER is only reasonable for pagecache folios */ VM_WARN_ONCE((unsigned long)mapping & PAGE_MAPPING_ANON, "Anonymous mapping always supports large folio");
- return IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE) && - test_bit(AS_LARGE_FOLIO_SUPPORT, &mapping->flags); + return mapping_max_folio_order(mapping) > 0; }
/* Return the maximum folio size for this pagecache mapping, in bytes. */ -static inline size_t mapping_max_folio_size(struct address_space *mapping) +static inline size_t mapping_max_folio_size(const struct address_space *mapping) { - if (mapping_large_folio_support(mapping)) - return PAGE_SIZE << MAX_PAGECACHE_ORDER; - return PAGE_SIZE; + return PAGE_SIZE << mapping_max_folio_order(mapping); }
static inline int filemap_nr_thps(struct address_space *mapping) diff --git a/mm/readahead.c b/mm/readahead.c index 438f142a3e74..c13c130efcca 100644 --- a/mm/readahead.c +++ b/mm/readahead.c @@ -513,10 +513,10 @@ void page_cache_ra_order(struct readahead_control *ractl,
limit = min(limit, index + ra->size - 1);
- if (new_order < MAX_PAGECACHE_ORDER) + if (new_order < mapping_max_folio_order(mapping)) new_order += 2;
- new_order = min_t(unsigned int, MAX_PAGECACHE_ORDER, new_order); + new_order = min(mapping_max_folio_order(mapping), new_order); new_order = min_t(unsigned int, new_order, ilog2(ra->size));
/* See comment in page_cache_ra_unbounded() */