From f5b7b74876cff5664ea8b2ef7f002c54cd6e7c90 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 1 Nov 2017 16:36:40 +0100 Subject: [PATCH] dax: Allow tuning whether dax_insert_mapping_entry() dirties entry Currently we dirty radix tree entry whenever dax_insert_mapping_entry() gets called for a write fault. With synchronous page faults we would like to insert clean radix tree entry and dirty it only once we call fdatasync() and update page tables to save some unnecessary cache flushing. Add 'dirty' argument to dax_insert_mapping_entry() for that. Reviewed-by: Ross Zwisler Reviewed-by: Christoph Hellwig Signed-off-by: Jan Kara Signed-off-by: Dan Williams --- fs/dax.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index 5ddf15161390..efc210ff6665 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -526,13 +526,13 @@ static int copy_user_dax(struct block_device *bdev, struct dax_device *dax_dev, static void *dax_insert_mapping_entry(struct address_space *mapping, struct vm_fault *vmf, void *entry, sector_t sector, - unsigned long flags) + unsigned long flags, bool dirty) { struct radix_tree_root *page_tree = &mapping->page_tree; void *new_entry; pgoff_t index = vmf->pgoff; - if (vmf->flags & FAULT_FLAG_WRITE) + if (dirty) __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); if (dax_is_zero_entry(entry) && !(flags & RADIX_DAX_ZERO_PAGE)) { @@ -569,7 +569,7 @@ static void *dax_insert_mapping_entry(struct address_space *mapping, entry = new_entry; } - if (vmf->flags & FAULT_FLAG_WRITE) + if (dirty) radix_tree_tag_set(page_tree, index, PAGECACHE_TAG_DIRTY); spin_unlock_irq(&mapping->tree_lock); @@ -881,7 +881,7 @@ static int dax_load_hole(struct address_space *mapping, void *entry, } entry2 = dax_insert_mapping_entry(mapping, vmf, entry, 0, - RADIX_DAX_ZERO_PAGE); + RADIX_DAX_ZERO_PAGE, false); if (IS_ERR(entry2)) { ret = VM_FAULT_SIGBUS; goto out; @@ -1182,7 +1182,7 @@ static int dax_iomap_pte_fault(struct vm_fault *vmf, pfn_t *pfnp, entry = dax_insert_mapping_entry(mapping, vmf, entry, dax_iomap_sector(&iomap, pos), - 0); + 0, write); if (IS_ERR(entry)) { error = PTR_ERR(entry); goto error_finish_iomap; @@ -1258,7 +1258,7 @@ static int dax_pmd_load_hole(struct vm_fault *vmf, struct iomap *iomap, goto fallback; ret = dax_insert_mapping_entry(mapping, vmf, entry, 0, - RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE); + RADIX_DAX_PMD | RADIX_DAX_ZERO_PAGE, false); if (IS_ERR(ret)) goto fallback; @@ -1379,7 +1379,7 @@ static int dax_iomap_pmd_fault(struct vm_fault *vmf, pfn_t *pfnp, entry = dax_insert_mapping_entry(mapping, vmf, entry, dax_iomap_sector(&iomap, pos), - RADIX_DAX_PMD); + RADIX_DAX_PMD, write); if (IS_ERR(entry)) goto finish_iomap; -- GitLab