proc_fill_cache(): switch to d_alloc_parallel()

... making it usable with directory locked shared

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 10 insertions, 5 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index b1755b23893e..15b60f1a346d 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -1819,12 +1819,17 @@ bool proc_fill_cache(struct file *file, struct dir_context *ctx,
 
         child = d_hash_and_lookup(dir, &qname);
         if (!child) {
-                child = d_alloc(dir, &qname);
-                if (!child)
-                        goto end_instantiate;
-                if (instantiate(d_inode(dir), child, task, ptr) < 0) {
-                        dput(child);
+                DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
+                child = d_alloc_parallel(dir, &qname, &wq);
+                if (IS_ERR(child))
                         goto end_instantiate;
+                if (d_in_lookup(child)) {
+                        int err = instantiate(d_inode(dir), child, task, ptr);
+                        d_lookup_done(child);
+                        if (err < 0) {
+                                dput(child);
+                                goto end_instantiate;
+                        }
                 }
         }
         inode = d_inode(child);