diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/dax.c | 60 | ||||
| -rw-r--r-- | fs/nilfs2/btnode.c | 4 |
2 files changed, 36 insertions, 28 deletions
@@ -98,12 +98,6 @@ static void *dax_make_entry(pfn_t pfn, unsigned long flags) return xa_mk_value(flags | (pfn_t_to_pfn(pfn) << DAX_SHIFT)); } -static void *dax_make_page_entry(struct page *page) -{ - pfn_t pfn = page_to_pfn_t(page); - return dax_make_entry(pfn, PageHead(page) ? DAX_PMD : 0); -} - static bool dax_is_locked(void *entry) { return xa_to_value(entry) & DAX_LOCKED; @@ -116,12 +110,12 @@ static unsigned int dax_entry_order(void *entry) return 0; } -static int dax_is_pmd_entry(void *entry) +static unsigned long dax_is_pmd_entry(void *entry) { return xa_to_value(entry) & DAX_PMD; } -static int dax_is_pte_entry(void *entry) +static bool dax_is_pte_entry(void *entry) { return !(xa_to_value(entry) & DAX_PMD); } @@ -222,9 +216,8 @@ static void *get_unlocked_entry(struct xa_state *xas) ewait.wait.func = wake_exceptional_entry_func; for (;;) { - entry = xas_load(xas); - if (!entry || xa_is_internal(entry) || - WARN_ON_ONCE(!xa_is_value(entry)) || + entry = xas_find_conflict(xas); + if (!entry || WARN_ON_ONCE(!xa_is_value(entry)) || !dax_is_locked(entry)) return entry; @@ -255,6 +248,7 @@ static void dax_unlock_entry(struct xa_state *xas, void *entry) { void *old; + BUG_ON(dax_is_locked(entry)); xas_reset(xas); xas_lock_irq(xas); old = xas_store(xas, entry); @@ -352,16 +346,27 @@ static struct page *dax_busy_page(void *entry) return NULL; } +/* + * dax_lock_mapping_entry - Lock the DAX entry corresponding to a page + * @page: The page whose entry we want to lock + * + * Context: Process context. + * Return: %true if the entry was locked or does not need to be locked. + */ bool dax_lock_mapping_entry(struct page *page) { XA_STATE(xas, NULL, 0); void *entry; + bool locked; + /* Ensure page->mapping isn't freed while we look at it */ + rcu_read_lock(); for (;;) { struct address_space *mapping = READ_ONCE(page->mapping); + locked = false; if (!dax_mapping(mapping)) - return false; + break; /* * In the device-dax case there's no need to lock, a @@ -370,8 +375,9 @@ bool dax_lock_mapping_entry(struct page *page) * otherwise we would not have a valid pfn_to_page() * translation. */ + locked = true; if (S_ISCHR(mapping->host->i_mode)) - return true; + break; xas.xa = &mapping->i_pages; xas_lock_irq(&xas); @@ -382,28 +388,35 @@ bool dax_lock_mapping_entry(struct page *page) xas_set(&xas, page->index); entry = xas_load(&xas); if (dax_is_locked(entry)) { + rcu_read_unlock(); entry = get_unlocked_entry(&xas); - /* Did the page move while we slept? */ - if (dax_to_pfn(entry) != page_to_pfn(page)) { - xas_unlock_irq(&xas); - continue; - } + xas_unlock_irq(&xas); + put_unlocked_entry(&xas, entry); + rcu_read_lock(); + continue; } dax_lock_entry(&xas, entry); xas_unlock_irq(&xas); - return true; + break; } + rcu_read_unlock(); + return locked; } void dax_unlock_mapping_entry(struct page *page) { struct address_space *mapping = page->mapping; XA_STATE(xas, &mapping->i_pages, page->index); + void *entry; if (S_ISCHR(mapping->host->i_mode)) return; - dax_unlock_entry(&xas, dax_make_page_entry(page)); + rcu_read_lock(); + entry = xas_load(&xas); + rcu_read_unlock(); + entry = dax_make_entry(page_to_pfn_t(page), dax_is_pmd_entry(entry)); + dax_unlock_entry(&xas, entry); } /* @@ -445,11 +458,9 @@ static void *grab_mapping_entry(struct xa_state *xas, retry: xas_lock_irq(xas); entry = get_unlocked_entry(xas); - if (xa_is_internal(entry)) - goto fallback; if (entry) { - if (WARN_ON_ONCE(!xa_is_value(entry))) { + if (!xa_is_value(entry)) { xas_set_err(xas, EIO); goto out_unlock; } @@ -1628,8 +1639,7 @@ dax_insert_pfn_mkwrite(struct vm_fault *vmf, pfn_t pfn, unsigned int order) /* Did we race with someone splitting entry or so? */ if (!entry || (order == 0 && !dax_is_pte_entry(entry)) || - (order == PMD_ORDER && (xa_is_internal(entry) || - !dax_is_pmd_entry(entry)))) { + (order == PMD_ORDER && !dax_is_pmd_entry(entry))) { put_unlocked_entry(&xas, entry); xas_unlock_irq(&xas); trace_dax_insert_pfn_mkwrite_no_entry(mapping->host, vmf, diff --git a/fs/nilfs2/btnode.c b/fs/nilfs2/btnode.c index de99db518571..f2129a5d9f23 100644 --- a/fs/nilfs2/btnode.c +++ b/fs/nilfs2/btnode.c @@ -266,9 +266,7 @@ void nilfs_btnode_abort_change_key(struct address_space *btnc, return; if (nbh == NULL) { /* blocksize == pagesize */ - xa_lock_irq(&btnc->i_pages); - __xa_erase(&btnc->i_pages, newkey); - xa_unlock_irq(&btnc->i_pages); + xa_erase_irq(&btnc->i_pages, newkey); unlock_page(ctxt->bh->b_page); } else brelse(nbh); |