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/fs/fs-writeback.c b/fs/fs-writeback.c
index 1280f91..4b12ba7 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -347,9 +347,9 @@ static void inode_switch_wbs_work_fn(struct work_struct *work)
* By the time control reaches here, RCU grace period has passed
* since I_WB_SWITCH assertion and all wb stat update transactions
* between unlocked_inode_to_wb_begin/end() are guaranteed to be
- * synchronizing against mapping->tree_lock.
+ * synchronizing against the i_pages lock.
*
- * Grabbing old_wb->list_lock, inode->i_lock and mapping->tree_lock
+ * Grabbing old_wb->list_lock, inode->i_lock and the i_pages lock
* gives us exclusion against all wb related operations on @inode
* including IO list manipulations and stat updates.
*/
@@ -361,7 +361,7 @@ static void inode_switch_wbs_work_fn(struct work_struct *work)
spin_lock_nested(&old_wb->list_lock, SINGLE_DEPTH_NESTING);
}
spin_lock(&inode->i_lock);
- spin_lock_irq(&mapping->tree_lock);
+ xa_lock_irq(&mapping->i_pages);
/*
* Once I_FREEING is visible under i_lock, the eviction path owns
@@ -373,22 +373,22 @@ static void inode_switch_wbs_work_fn(struct work_struct *work)
/*
* Count and transfer stats. Note that PAGECACHE_TAG_DIRTY points
* to possibly dirty pages while PAGECACHE_TAG_WRITEBACK points to
- * pages actually under underwriteback.
+ * pages actually under writeback.
*/
- radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter, 0,
+ radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter, 0,
PAGECACHE_TAG_DIRTY) {
struct page *page = radix_tree_deref_slot_protected(slot,
- &mapping->tree_lock);
+ &mapping->i_pages.xa_lock);
if (likely(page) && PageDirty(page)) {
dec_wb_stat(old_wb, WB_RECLAIMABLE);
inc_wb_stat(new_wb, WB_RECLAIMABLE);
}
}
- radix_tree_for_each_tagged(slot, &mapping->page_tree, &iter, 0,
+ radix_tree_for_each_tagged(slot, &mapping->i_pages, &iter, 0,
PAGECACHE_TAG_WRITEBACK) {
struct page *page = radix_tree_deref_slot_protected(slot,
- &mapping->tree_lock);
+ &mapping->i_pages.xa_lock);
if (likely(page)) {
WARN_ON_ONCE(!PageWriteback(page));
dec_wb_stat(old_wb, WB_WRITEBACK);
@@ -430,7 +430,7 @@ static void inode_switch_wbs_work_fn(struct work_struct *work)
*/
smp_store_release(&inode->i_state, inode->i_state & ~I_WB_SWITCH);
- spin_unlock_irq(&mapping->tree_lock);
+ xa_unlock_irq(&mapping->i_pages);
spin_unlock(&inode->i_lock);
spin_unlock(&new_wb->list_lock);
spin_unlock(&old_wb->list_lock);
@@ -506,8 +506,8 @@ static void inode_switch_wbs(struct inode *inode, int new_wb_id)
/*
* In addition to synchronizing among switchers, I_WB_SWITCH tells
- * the RCU protected stat update paths to grab the mapping's
- * tree_lock so that stat transfer can synchronize against them.
+ * the RCU protected stat update paths to grab the i_page
+ * lock so that stat transfer can synchronize against them.
* Let's continue after I_WB_SWITCH is guaranteed to be visible.
*/
call_rcu(&isw->rcu_head, inode_switch_wbs_rcu_fn);