>From Matthew Wilcox: The one caller of DAX lock/unlock page already calls compound_head(), so use page_folio() instead, then use a folio throughout the DAX code to remove uses of page->mapping and page->index. [1] The additional change to [1] is comments added to mf_generic_kill_procs(). [1] https://lore.kernel.org/linux-mm/b2b0fce8-b7f8-420e-0945-ab9581b23d9a@xxxxxxxxxx/T/ Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Acked-by: Naoya Horiguchi <naoya.horiguchi@xxxxxxx> Signed-off-by: Jane Chu <jane.chu@xxxxxxxxxx> --- fs/dax.c | 24 ++++++++++++------------ include/linux/dax.h | 10 +++++----- mm/memory-failure.c | 29 ++++++++++++++++------------- 3 files changed, 33 insertions(+), 30 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 906ecbd541a3..c70d4da047db 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -426,23 +426,23 @@ static struct page *dax_busy_page(void *entry) return NULL; } -/* - * dax_lock_page - Lock the DAX entry corresponding to a page - * @page: The page whose entry we want to lock +/** + * dax_lock_folio - Lock the DAX entry corresponding to a folio + * @folio: The folio whose entry we want to lock * * Context: Process context. - * Return: A cookie to pass to dax_unlock_page() or 0 if the entry could + * Return: A cookie to pass to dax_unlock_folio() or 0 if the entry could * not be locked. */ -dax_entry_t dax_lock_page(struct page *page) +dax_entry_t dax_lock_folio(struct folio *folio) { XA_STATE(xas, NULL, 0); void *entry; - /* Ensure page->mapping isn't freed while we look at it */ + /* Ensure folio->mapping isn't freed while we look at it */ rcu_read_lock(); for (;;) { - struct address_space *mapping = READ_ONCE(page->mapping); + struct address_space *mapping = READ_ONCE(folio->mapping); entry = NULL; if (!mapping || !dax_mapping(mapping)) @@ -461,11 +461,11 @@ dax_entry_t dax_lock_page(struct page *page) xas.xa = &mapping->i_pages; xas_lock_irq(&xas); - if (mapping != page->mapping) { + if (mapping != folio->mapping) { xas_unlock_irq(&xas); continue; } - xas_set(&xas, page->index); + xas_set(&xas, folio->index); entry = xas_load(&xas); if (dax_is_locked(entry)) { rcu_read_unlock(); @@ -481,10 +481,10 @@ dax_entry_t dax_lock_page(struct page *page) return (dax_entry_t)entry; } -void dax_unlock_page(struct page *page, dax_entry_t cookie) +void dax_unlock_folio(struct folio *folio, dax_entry_t cookie) { - struct address_space *mapping = page->mapping; - XA_STATE(xas, &mapping->i_pages, page->index); + struct address_space *mapping = folio->mapping; + XA_STATE(xas, &mapping->i_pages, folio->index); if (S_ISCHR(mapping->host->i_mode)) return; diff --git a/include/linux/dax.h b/include/linux/dax.h index 261944ec0887..711deb72c109 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -159,8 +159,8 @@ int dax_writeback_mapping_range(struct address_space *mapping, struct page *dax_layout_busy_page(struct address_space *mapping); struct page *dax_layout_busy_page_range(struct address_space *mapping, loff_t start, loff_t end); -dax_entry_t dax_lock_page(struct page *page); -void dax_unlock_page(struct page *page, dax_entry_t cookie); +dax_entry_t dax_lock_folio(struct folio *folio); +void dax_unlock_folio(struct folio *folio, dax_entry_t cookie); dax_entry_t dax_lock_mapping_entry(struct address_space *mapping, unsigned long index, struct page **page); void dax_unlock_mapping_entry(struct address_space *mapping, @@ -182,14 +182,14 @@ static inline int dax_writeback_mapping_range(struct address_space *mapping, return -EOPNOTSUPP; } -static inline dax_entry_t dax_lock_page(struct page *page) +static inline dax_entry_t dax_lock_folio(struct folio *folio) { - if (IS_DAX(page->mapping->host)) + if (IS_DAX(folio->mapping->host)) return ~0UL; return 0; } -static inline void dax_unlock_page(struct page *page, dax_entry_t cookie) +static inline void dax_unlock_folio(struct folio *folio, dax_entry_t cookie) { } diff --git a/mm/memory-failure.c b/mm/memory-failure.c index fe121fdb05f7..6c2c9af0caa0 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -1710,20 +1710,23 @@ static void unmap_and_kill(struct list_head *to_kill, unsigned long pfn, kill_procs(to_kill, flags & MF_MUST_KILL, false, pfn, flags); } +/* + * Only dev_pagemap pages get here, such as fsdax when the filesystem + * either do not claim or fails to claim a hwpoison event, or devdax. + * The fsdax pages are initialized per base page, and the devdax pages + * could be initialized either as base pages, or as compound pages with + * vmemmap optimization enabled. Devdax is simplistic in its dealing with + * hwpoison, such that, if a subpage of a compound page is poisoned, + * simply mark the compound head page is by far sufficient. + */ static int mf_generic_kill_procs(unsigned long long pfn, int flags, struct dev_pagemap *pgmap) { - struct page *page = pfn_to_page(pfn); + struct folio *folio = pfn_folio(pfn); LIST_HEAD(to_kill); dax_entry_t cookie; int rc = 0; - /* - * Pages instantiated by device-dax (not filesystem-dax) - * may be compound pages. - */ - page = compound_head(page); - /* * Prevent the inode from being freed while we are interrogating * the address_space, typically this would be handled by @@ -1731,11 +1734,11 @@ static int mf_generic_kill_procs(unsigned long long pfn, int flags, * also prevents changes to the mapping of this pfn until * poison signaling is complete. */ - cookie = dax_lock_page(page); + cookie = dax_lock_folio(folio); if (!cookie) return -EBUSY; - if (hwpoison_filter(page)) { + if (hwpoison_filter(&folio->page)) { rc = -EOPNOTSUPP; goto unlock; } @@ -1757,7 +1760,7 @@ static int mf_generic_kill_procs(unsigned long long pfn, int flags, * Use this flag as an indication that the dax page has been * remapped UC to prevent speculative consumption of poison. */ - SetPageHWPoison(page); + SetPageHWPoison(&folio->page); /* * Unlike System-RAM there is no possibility to swap in a @@ -1766,11 +1769,11 @@ static int mf_generic_kill_procs(unsigned long long pfn, int flags, * SIGBUS (i.e. MF_MUST_KILL) */ flags |= MF_ACTION_REQUIRED | MF_MUST_KILL; - collect_procs(page, &to_kill, true); + collect_procs(&folio->page, &to_kill, true); - unmap_and_kill(&to_kill, pfn, page->mapping, page->index, flags); + unmap_and_kill(&to_kill, pfn, folio->mapping, folio->index, flags); unlock: - dax_unlock_page(page, cookie); + dax_unlock_folio(folio, cookie); return rc; } base-commit: 727dbda16b83600379061c4ca8270ef3e2f51922 -- 2.18.4
