CIFS: Separate page reading from user read

Reviewed-by: Shirish Pargaonkar <spargaonkar@suse.com>
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index d6279185e2f0bb6caa525f83eb92f7791e5c6ea7..7df4e4658d743ca359058b5a62fed3df6b50338b 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2932,43 +2932,23 @@ cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
        return total_read > 0 && result != -EAGAIN ? total_read : result;
 }
 
-ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
+static int
+cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
+                    struct cifs_sb_info *cifs_sb, struct list_head *rdata_list)
 {
-       struct file *file = iocb->ki_filp;
-       ssize_t rc;
-       size_t len, cur_len;
-       ssize_t total_read = 0;
-       loff_t offset = iocb->ki_pos;
+       struct cifs_readdata *rdata;
        unsigned int npages;
-       struct cifs_sb_info *cifs_sb;
-       struct cifs_tcon *tcon;
-       struct cifsFileInfo *open_file;
-       struct cifs_readdata *rdata, *tmp;
-       struct list_head rdata_list;
+       size_t cur_len;
+       int rc;
        pid_t pid;
 
-       len = iov_iter_count(to);
-       if (!len)
-               return 0;
-
-       INIT_LIST_HEAD(&rdata_list);
-       cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
-       open_file = file->private_data;
-       tcon = tlink_tcon(open_file->tlink);
-
-       if (!tcon->ses->server->ops->async_readv)
-               return -ENOSYS;
-
        if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
                pid = open_file->pid;
        else
                pid = current->tgid;
 
-       if ((file->f_flags & O_ACCMODE) == O_WRONLY)
-               cifs_dbg(FYI, "attempting read on write only file instance\n");
-
        do {
-               cur_len = min_t(const size_t, len - total_read, cifs_sb->rsize);
+               cur_len = min_t(const size_t, len, cifs_sb->rsize);
                npages = DIV_ROUND_UP(cur_len, PAGE_SIZE);
 
                /* allocate a readdata struct */
@@ -2999,11 +2979,44 @@ error:
                        break;
                }
 
-               list_add_tail(&rdata->list, &rdata_list);
+               list_add_tail(&rdata->list, rdata_list);
                offset += cur_len;
                len -= cur_len;
        } while (len > 0);
 
+       return rc;
+}
+
+ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
+{
+       struct file *file = iocb->ki_filp;
+       ssize_t rc;
+       size_t len;
+       ssize_t total_read = 0;
+       loff_t offset = iocb->ki_pos;
+       struct cifs_sb_info *cifs_sb;
+       struct cifs_tcon *tcon;
+       struct cifsFileInfo *open_file;
+       struct cifs_readdata *rdata, *tmp;
+       struct list_head rdata_list;
+
+       len = iov_iter_count(to);
+       if (!len)
+               return 0;
+
+       INIT_LIST_HEAD(&rdata_list);
+       cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
+       open_file = file->private_data;
+       tcon = tlink_tcon(open_file->tlink);
+
+       if (!tcon->ses->server->ops->async_readv)
+               return -ENOSYS;
+
+       if ((file->f_flags & O_ACCMODE) == O_WRONLY)
+               cifs_dbg(FYI, "attempting read on write only file instance\n");
+
+       rc = cifs_send_async_read(offset, len, open_file, cifs_sb, &rdata_list);
+
        /* if at least one read request send succeeded, then reset rc */
        if (!list_empty(&rdata_list))
                rc = 0;