Reviewed-by: Shirish Pargaonkar <spargaonkar@xxxxxxxx>
On Mon, Jul 21, 2014 at 10:45 AM, Pavel Shilovsky <pshilovsky@xxxxxxxxx> wrote:
> If a server changes maximum buffer size for read (rsize) requests
> on reconnect we can fail on repeating with a big size buffer on
> -EAGAIN error in user read. Fix this by checking rsize all the
> time before repeating requests.
>
> Signed-off-by: Pavel Shilovsky <pshilovsky@xxxxxxxxx>
> ---
> fs/cifs/file.c | 45 ++++++++++++++++++++++-----------------------
> 1 file changed, 22 insertions(+), 23 deletions(-)
>
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index 7df4e46..bbc3859 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -2828,26 +2828,6 @@ cifs_uncached_readdata_release(struct kref *refcount)
> cifs_readdata_release(refcount);
> }
>
> -static int
> -cifs_retry_async_readv(struct cifs_readdata *rdata)
> -{
> - int rc;
> - struct TCP_Server_Info *server;
> -
> - server = tlink_tcon(rdata->cfile->tlink)->ses->server;
> -
> - do {
> - if (rdata->cfile->invalidHandle) {
> - rc = cifs_reopen_file(rdata->cfile, true);
> - if (rc != 0)
> - continue;
> - }
> - rc = server->ops->async_readv(rdata);
> - } while (rc == -EAGAIN);
> -
> - return rc;
> -}
> -
> /**
> * cifs_readdata_to_iov - copy data from pages in response to an iovec
> * @rdata: the readdata response with list of pages holding data
> @@ -2941,6 +2921,9 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
> size_t cur_len;
> int rc;
> pid_t pid;
> + struct TCP_Server_Info *server;
> +
> + server = tlink_tcon(open_file->tlink)->ses->server;
>
> if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD)
> pid = open_file->pid;
> @@ -2971,11 +2954,15 @@ cifs_send_async_read(loff_t offset, size_t len, struct cifsFileInfo *open_file,
> rdata->pagesz = PAGE_SIZE;
> rdata->read_into_pages = cifs_uncached_read_into_pages;
>
> - rc = cifs_retry_async_readv(rdata);
> + if (!rdata->cfile->invalidHandle ||
> + !cifs_reopen_file(rdata->cfile, true))
> + rc = server->ops->async_readv(rdata);
> error:
> if (rc) {
> kref_put(&rdata->refcount,
> cifs_uncached_readdata_release);
> + if (rc == -EAGAIN)
> + continue;
> break;
> }
>
> @@ -3023,8 +3010,8 @@ ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
>
> len = iov_iter_count(to);
> /* the loop below should proceed in the order of increasing offsets */
> +again:
> list_for_each_entry_safe(rdata, tmp, &rdata_list, list) {
> - again:
> if (!rc) {
> /* FIXME: freezable sleep too? */
> rc = wait_for_completion_killable(&rdata->done);
> @@ -3034,7 +3021,19 @@ ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to)
> rc = rdata->result;
> /* resend call if it's a retryable error */
> if (rc == -EAGAIN) {
> - rc = cifs_retry_async_readv(rdata);
> + struct list_head tmp_list;
> +
> + list_del_init(&rdata->list);
> + INIT_LIST_HEAD(&tmp_list);
> +
> + rc = cifs_send_async_read(rdata->offset,
> + rdata->bytes, rdata->cfile,
> + cifs_sb, &tmp_list);
> +
> + list_splice(&tmp_list, &rdata_list);
> +
> + kref_put(&rdata->refcount,
> + cifs_uncached_readdata_release);
> goto again;
> }
> } else {
> --
> 1.8.1.2
>
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