[PATCH v6 04/13] filesystem-dax: Set page->index
From: Dan Williams <hidden>
Date: 2018-07-14 04:49:50
Also in:
linux-fsdevel, lkml, nvdimm
Subsystem:
filesystem direct access (dax), filesystems (vfs and infrastructure), the rest · Maintainers:
Dan Williams, Alexander Viro, Christian Brauner, Linus Torvalds
In support of enabling memory_failure() handling for filesystem-dax mappings, set ->index to the pgoff of the page. The rmap implementation requires ->index to bound the search through the vma interval tree. The index is set and cleared at dax_associate_entry() and dax_disassociate_entry() time respectively. Cc: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ross Zwisler <redacted> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <redacted> --- fs/dax.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-)
diff --git a/fs/dax.c b/fs/dax.c
index 641192808bb6..4de11ed463ce 100644
--- a/fs/dax.c
+++ b/fs/dax.c@@ -319,18 +319,27 @@ static unsigned long dax_radix_end_pfn(void *entry) for (pfn = dax_radix_pfn(entry); \ pfn < dax_radix_end_pfn(entry); pfn++) -static void dax_associate_entry(void *entry, struct address_space *mapping) +/* + * TODO: for reflink+dax we need a way to associate a single page with + * multiple address_space instances at different linear_page_index() + * offsets. + */ +static void dax_associate_entry(void *entry, struct address_space *mapping, + struct vm_area_struct *vma, unsigned long address) { - unsigned long pfn; + unsigned long size = dax_entry_size(entry), pfn, index; + int i = 0; if (IS_ENABLED(CONFIG_FS_DAX_LIMITED)) return; + index = linear_page_index(vma, address & ~(size - 1)); for_each_mapped_pfn(entry, pfn) { struct page *page = pfn_to_page(pfn); WARN_ON_ONCE(page->mapping); page->mapping = mapping; + page->index = index + i++; } }
@@ -348,6 +357,7 @@ static void dax_disassociate_entry(void *entry, struct address_space *mapping, WARN_ON_ONCE(trunc && page_ref_count(page) > 1); WARN_ON_ONCE(page->mapping && page->mapping != mapping); page->mapping = NULL; + page->index = 0; } }
@@ -701,7 +711,7 @@ static void *dax_insert_mapping_entry(struct address_space *mapping, new_entry = dax_radix_locked_entry(pfn, flags); if (dax_entry_size(entry) != dax_entry_size(new_entry)) { dax_disassociate_entry(entry, mapping, false); - dax_associate_entry(new_entry, mapping); + dax_associate_entry(new_entry, mapping, vmf->vma, vmf->address); } if (dax_is_zero_entry(entry) || dax_is_empty_entry(entry)) {