fuse: invalidate dentry on EEXIST creates or ENOENT deletes

The EEXIST errors returned from server are strong sign that a local
negative dentry should be invalidated.  Similarly, The ENOENT errors from
server can also be a sign of revalidate failure.

This commit invalidates dentries on EEXIST creates and ENOENT deletes by
calling fuse_invalidate_entry(), which improves the consistency with no
performance degradation.

Signed-off-by: Jiachen Zhang <zhangjiachen.jaycee@bytedance.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 3db9d26d341e40a961db2fbf7e23f3686129baa2..e190d09f220d9ce89ca2e4710685e86b45ea5986 100644 (file)
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -749,7 +749,8 @@ static int fuse_atomic_open(struct inode *dir, struct dentry *entry,
        if (err == -ENOSYS) {
                fc->no_create = 1;
                goto mknod;
-       }
+       } else if (err == -EEXIST)
+               fuse_invalidate_entry(entry);
 out_dput:
        dput(res);
        return err;
@@ -829,6 +830,8 @@ static int create_new_entry(struct fuse_mount *fm, struct fuse_args *args,
        return 0;
 
  out_put_forget_req:
+       if (err == -EEXIST)
+               fuse_invalidate_entry(entry);
        kfree(forget);
        return err;
 }
@@ -980,7 +983,7 @@ static int fuse_unlink(struct inode *dir, struct dentry *entry)
        if (!err) {
                fuse_dir_changed(dir);
                fuse_entry_unlinked(entry);
-       } else if (err == -EINTR)
+       } else if (err == -EINTR || err == -ENOENT)
                fuse_invalidate_entry(entry);
        return err;
 }
@@ -1003,7 +1006,7 @@ static int fuse_rmdir(struct inode *dir, struct dentry *entry)
        if (!err) {
                fuse_dir_changed(dir);
                fuse_entry_unlinked(entry);
-       } else if (err == -EINTR)
+       } else if (err == -EINTR || err == -ENOENT)
                fuse_invalidate_entry(entry);
        return err;
 }
@@ -1044,7 +1047,7 @@ static int fuse_rename_common(struct inode *olddir, struct dentry *oldent,
                /* newent will end up negative */
                if (!(flags & RENAME_EXCHANGE) && d_really_is_positive(newent))
                        fuse_entry_unlinked(newent);
-       } else if (err == -EINTR) {
+       } else if (err == -EINTR || err == -ENOENT) {
                /* If request was interrupted, DEITY only knows if the
                   rename actually took place.  If the invalidation
                   fails (e.g. some process has CWD under the renamed