Commit 038bc961 authored Jun 27, 2014 by Pavel Shilovsky Committed by Steve French Aug 02, 2014

CIFS: Fix async reading on reconnects



If we get into read_into_pages() from cifs_readv_receive() and then
loose a network, we issue cifs_reconnect that moves all mids to
a private list and issue their callbacks. The callback of the async
read request sets a mid to retry, frees it and wakes up a process
that waits on the rdata completion.

After the connection is established we return from read_into_pages()
with a short read, use the mid that was freed before and try to read
the remaining data from the a newly created socket. Both actions are
not what we want to do. In reconnect cases (-EAGAIN) we should not
mask off the error with a short read but should return the error
code instead.

Acked-by: Jeff Layton <jlayton@samba.org>
Cc: stable@vger.kernel.org
Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>

parent cc87c47d

fs/cifs/file.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -2823,7 +2823,7 @@ cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
		total_read += result;
		}

		return total_read > 0 ? total_read : result;
		return total_read > 0 && result != -EAGAIN ? total_read : result;
		}

		ssize_t cifs_user_readv(struct kiocb iocb, struct iov_iter to)
		@@ -3231,7 +3231,7 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
		total_read += result;
		}

		return total_read > 0 ? total_read : result;
		return total_read > 0 && result != -EAGAIN ? total_read : result;
		}

		static int cifs_readpages(struct file file, struct address_space mapping,

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