introduce a parallel variant of ->iterate()
New method: ->iterate_shared(). Same arguments as in ->iterate(),
called with the directory locked only shared. Once all filesystems
switch, the old one will be gone.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/readdir.c b/fs/readdir.c
index d7308b8..a86c6c0 100644
--- a/fs/readdir.c
+++ b/fs/readdir.c
@@ -24,15 +24,21 @@
int iterate_dir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
+ bool shared = false;
int res = -ENOTDIR;
- if (!file->f_op->iterate)
+ if (file->f_op->iterate_shared)
+ shared = true;
+ else if (!file->f_op->iterate)
goto out;
res = security_file_permission(file, MAY_READ);
if (res)
goto out;
- inode_lock(inode);
+ if (shared)
+ inode_lock_shared(inode);
+ else
+ inode_lock(inode);
// res = mutex_lock_killable(&inode->i_mutex);
// if (res)
// goto out;
@@ -40,12 +46,18 @@
res = -ENOENT;
if (!IS_DEADDIR(inode)) {
ctx->pos = file->f_pos;
- res = file->f_op->iterate(file, ctx);
+ if (shared)
+ res = file->f_op->iterate_shared(file, ctx);
+ else
+ res = file->f_op->iterate(file, ctx);
file->f_pos = ctx->pos;
fsnotify_access(file);
file_accessed(file);
}
- inode_unlock(inode);
+ if (shared)
+ inode_unlock_shared(inode);
+ else
+ inode_unlock(inode);
out:
return res;
}