fs: reduce dcache_inode_lock width in lru scanning

Signed-off-by: Nick Piggin <npiggin@kernel.dk>

1 files changed, 8 insertions, 8 deletions

diff --git a/fs/dcache.c b/fs/dcache.c
index 195706374697..fe8f28a2878e 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -621,7 +621,7 @@ static void shrink_dentry_list(struct list_head *list)
                 dentry = list_entry(list->prev, struct dentry, d_lru);
 
                 if (!spin_trylock(&dentry->d_lock)) {
-relock:
+relock1:
                         spin_unlock(&dcache_lru_lock);
                         cpu_relax();
                         spin_lock(&dcache_lru_lock);
@@ -638,20 +638,24 @@ relock:
                         spin_unlock(&dentry->d_lock);
                         continue;
                 }
+                if (!spin_trylock(&dcache_inode_lock)) {
+relock2:
+                        spin_unlock(&dentry->d_lock);
+                        goto relock1;
+                }
                 if (IS_ROOT(dentry))
                         parent = NULL;
                 else
                         parent = dentry->d_parent;
                 if (parent && !spin_trylock(&parent->d_lock)) {
-                        spin_unlock(&dentry->d_lock);
-                        goto relock;
+                        spin_unlock(&dcache_inode_lock);
+                        goto relock2;
                 }
                 __dentry_lru_del(dentry);
                 spin_unlock(&dcache_lru_lock);
 
                 prune_one_dentry(dentry, parent);
                 /* dcache_inode_lock and dentry->d_lock dropped */
-                spin_lock(&dcache_inode_lock);
                 spin_lock(&dcache_lru_lock);
         }
 }
@@ -672,7 +676,6 @@ static void __shrink_dcache_sb(struct super_block *sb, int *count, int flags)
         LIST_HEAD(tmp);
         int cnt = *count;
 
-        spin_lock(&dcache_inode_lock);
 relock:
         spin_lock(&dcache_lru_lock);
         while (!list_empty(&sb->s_dentry_lru)) {
@@ -711,7 +714,6 @@ relock:
         if (!list_empty(&referenced))
                 list_splice(&referenced, &sb->s_dentry_lru);
         spin_unlock(&dcache_lru_lock);
-        spin_unlock(&dcache_inode_lock);
 }
 
 /**
@@ -800,14 +802,12 @@ void shrink_dcache_sb(struct super_block *sb)
 {
         LIST_HEAD(tmp);
 
-        spin_lock(&dcache_inode_lock);
         spin_lock(&dcache_lru_lock);
         while (!list_empty(&sb->s_dentry_lru)) {
                 list_splice_init(&sb->s_dentry_lru, &tmp);
                 shrink_dentry_list(&tmp);
         }
         spin_unlock(&dcache_lru_lock);
-        spin_unlock(&dcache_inode_lock);
 }
 EXPORT_SYMBOL(shrink_dcache_sb);