Instead of checking the two counters (nrpages and nrexceptional), we
can just check whether i_pages is empty.
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
fs/block_dev.c | 2 +-
fs/dax.c | 2 +-
include/linux/pagemap.h | 5 +++++
mm/truncate.c | 18 +++---------------
4 files changed, 10 insertions(+), 17 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 0ae656e022fd..2a77bd2c6144 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -79,7 +79,7 @@ static void kill_bdev(struct block_device *bdev)
{
struct address_space *mapping = bdev->bd_inode->i_mapping;
- if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
+ if (page_cache_empty(mapping))
return;
invalidate_bh_lrus();
diff --git a/fs/dax.c b/fs/dax.c
index 11b16729b86f..2f75ee2cd41f 100644
--- a/fs/dax.c
+++ b/fs/dax.c
@@ -949,7 +949,7 @@ int dax_writeback_mapping_range(struct address_space *mapping,
if (WARN_ON_ONCE(inode->i_blkbits != PAGE_SHIFT))
return -EIO;
- if (!mapping->nrexceptional || wbc->sync_mode != WB_SYNC_ALL)
+ if (page_cache_empty(mapping) || wbc->sync_mode != WB_SYNC_ALL)
return 0;
trace_dax_writeback_range(inode, xas.xa_index, end_index);
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 484a36185bb5..a474a92a2a72 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -18,6 +18,11 @@
struct pagevec;
+static inline bool page_cache_empty(struct address_space *mapping)
+{
+ return xa_empty(&mapping->i_pages);
+}
+
/*
* Bits in mapping->flags.
*/
diff --git a/mm/truncate.c b/mm/truncate.c
index dd9ebc1da356..7c4c8ac140be 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -300,7 +300,7 @@ void truncate_inode_pages_range(struct address_space *mapping,
pgoff_t index;
int i;
- if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
+ if (page_cache_empty(mapping))
goto out;
/* Offsets within partial pages */
@@ -488,9 +488,6 @@ EXPORT_SYMBOL(truncate_inode_pages);
*/
void truncate_inode_pages_final(struct address_space *mapping)
{
- unsigned long nrexceptional;
- unsigned long nrpages;
-
/*
* Page reclaim can not participate in regular inode lifetime
* management (can't call iput()) and thus can race with the
@@ -500,16 +497,7 @@ void truncate_inode_pages_final(struct address_space *mapping)
*/
mapping_set_exiting(mapping);
- /*
- * When reclaim installs eviction entries, it increases
- * nrexceptional first, then decreases nrpages. Make sure we see
- * this in the right order or we might miss an entry.
- */
- nrpages = mapping->nrpages;
- smp_rmb();
- nrexceptional = mapping->nrexceptional;
-
- if (nrpages || nrexceptional) {
+ if (!page_cache_empty(mapping)) {
/*
* As truncation uses a lockless tree lookup, cycle
* the tree lock to make sure any ongoing tree
@@ -692,7 +680,7 @@ int invalidate_inode_pages2_range(struct address_space *mapping,
int ret2 = 0;
int did_range_unmap = 0;
- if (mapping->nrpages == 0 && mapping->nrexceptional == 0)
+ if (page_cache_empty(mapping))
goto out;
pagevec_init(&pvec);
--
2.27.0
