page cache: use xa_lock
Remove the address_space ->tree_lock and use the xa_lock newly added to
the radix_tree_root. Rename the address_space ->page_tree to ->i_pages,
since we don't really care that it's a tree.
[willy@infradead.org: fix nds32, fs/dax.c]
Link: http://lkml.kernel.org/r/20180406145415.GB20605@bombadil.infradead.orgLink: http://lkml.kernel.org/r/20180313132639.17387-9-willy@infradead.org
Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2aa02ca..92efaf1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -13,6 +13,7 @@
#include <linux/list_lru.h>
#include <linux/llist.h>
#include <linux/radix-tree.h>
+#include <linux/xarray.h>
#include <linux/rbtree.h>
#include <linux/init.h>
#include <linux/pid.h>
@@ -390,12 +391,11 @@ int pagecache_write_end(struct file *, struct address_space *mapping,
struct address_space {
struct inode *host; /* owner: inode, block_device */
- struct radix_tree_root page_tree; /* radix tree of all pages */
- spinlock_t tree_lock; /* and lock protecting it */
+ struct radix_tree_root i_pages; /* cached pages */
atomic_t i_mmap_writable;/* count VM_SHARED mappings */
struct rb_root_cached i_mmap; /* tree of private and shared mappings */
struct rw_semaphore i_mmap_rwsem; /* protect tree, count, list */
- /* Protected by tree_lock together with the radix tree */
+ /* Protected by the i_pages lock */
unsigned long nrpages; /* number of total pages */
/* number of shadow or DAX exceptional entries */
unsigned long nrexceptional;
@@ -1989,7 +1989,7 @@ static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
*
* I_WB_SWITCH Cgroup bdi_writeback switching in progress. Used to
* synchronize competing switching instances and to tell
- * wb stat updates to grab mapping->tree_lock. See
+ * wb stat updates to grab the i_pages lock. See
* inode_switch_wb_work_fn() for details.
*
* I_OVL_INUSE Used by overlayfs to get exclusive ownership on upper