On Wed, 9 Jul 2014 16:48:47 +0400
Pavel Shilovsky <pshilovsky@xxxxxxxxx> wrote:
> that lets us not mix EAGAIN error code with reconnect and
> prevent possible errors further.
>
> Signed-off-by: Pavel Shilovsky <pshilovsky@xxxxxxxxx>
> ---
> fs/cifs/cifsglob.h | 2 +-
> fs/cifs/cifsproto.h | 2 +-
> fs/cifs/cifssmb.c | 11 ++++++++---
> fs/cifs/connect.c | 11 +++++++++--
> fs/cifs/file.c | 16 ++++++++++------
> 5 files changed, 29 insertions(+), 13 deletions(-)
>
> diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
> index f33ff4c..f57e5bc 100644
> --- a/fs/cifs/cifsglob.h
> +++ b/fs/cifs/cifsglob.h
> @@ -1064,7 +1064,7 @@ struct cifs_readdata {
> struct work_struct work;
> int (*read_into_pages)(struct TCP_Server_Info *server,
> struct cifs_readdata *rdata,
> - unsigned int len);
> + unsigned int len, bool *was_reconnect);
> struct kvec iov;
> unsigned int pagesz;
> unsigned int tailsz;
> diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
> index c31ce98..8e4f826 100644
> --- a/fs/cifs/cifsproto.h
> +++ b/fs/cifs/cifsproto.h
> @@ -184,7 +184,7 @@ extern int cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
> unsigned int to_read);
> extern int cifs_readv_from_socket(struct TCP_Server_Info *server,
> struct kvec *iov_orig, unsigned int nr_segs,
> - unsigned int to_read);
> + unsigned int to_read, bool *was_reconnect);
> extern void cifs_setup_cifs_sb(struct smb_vol *pvolume_info,
> struct cifs_sb_info *cifs_sb);
> extern int cifs_match_super(struct super_block *, void *);
> diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
> index e411d2e..6697b78 100644
> --- a/fs/cifs/cifssmb.c
> +++ b/fs/cifs/cifssmb.c
> @@ -1425,6 +1425,7 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
> struct cifs_readdata *rdata = mid->callback_data;
> char *buf = server->smallbuf;
> unsigned int buflen = get_rfc1002_length(buf) + 4;
> + bool was_reconnect;
>
> cifs_dbg(FYI, "%s: mid=%llu offset=%llu bytes=%u\n",
> __func__, mid->mid, rdata->offset, rdata->bytes);
> @@ -1440,7 +1441,7 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
> rdata->iov.iov_base = buf + HEADER_SIZE(server) - 1;
> rdata->iov.iov_len = len;
>
> - length = cifs_readv_from_socket(server, &rdata->iov, 1, len);
> + length = cifs_readv_from_socket(server, &rdata->iov, 1, len, NULL);
> if (length < 0)
> return length;
> server->total_read += length;
> @@ -1488,7 +1489,8 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
> /* read any junk before data into the rest of smallbuf */
> rdata->iov.iov_base = buf + server->total_read;
> rdata->iov.iov_len = len;
> - length = cifs_readv_from_socket(server, &rdata->iov, 1, len);
> + length = cifs_readv_from_socket(server, &rdata->iov, 1, len,
> + NULL);
> if (length < 0)
> return length;
> server->total_read += length;
> @@ -1508,7 +1510,10 @@ cifs_readv_receive(struct TCP_Server_Info *server, struct mid_q_entry *mid)
> return cifs_readv_discard(server, mid);
> }
>
> - length = rdata->read_into_pages(server, rdata, data_len);
> + length = rdata->read_into_pages(server, rdata, data_len,
> + &was_reconnect);
> + if (was_reconnect)
> + return -EAGAIN;
> if (length < 0)
> return length;
>
> diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
> index 20d75b8..f6a8107 100644
> --- a/fs/cifs/connect.c
> +++ b/fs/cifs/connect.c
> @@ -538,13 +538,15 @@ get_server_iovec(struct TCP_Server_Info *server, unsigned int nr_segs)
>
> int
> cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
> - unsigned int nr_segs, unsigned int to_read)
> + unsigned int nr_segs, unsigned int to_read,
> + bool *was_reconnect)
> {
> int length = 0;
> int total_read;
> unsigned int segs;
> struct msghdr smb_msg;
> struct kvec *iov;
> + bool rec = false;
>
> iov = get_server_iovec(server, nr_segs);
> if (!iov)
> @@ -557,6 +559,7 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
> try_to_freeze();
>
> if (server_unresponsive(server)) {
> + rec = true;
> total_read = -EAGAIN;
> break;
> }
> @@ -571,6 +574,7 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
> break;
> } else if (server->tcpStatus == CifsNeedReconnect) {
> cifs_reconnect(server);
> + rec = true;
> total_read = -EAGAIN;
> break;
> } else if (length == -ERESTARTSYS ||
> @@ -588,10 +592,13 @@ cifs_readv_from_socket(struct TCP_Server_Info *server, struct kvec *iov_orig,
> cifs_dbg(FYI, "Received no data or error: expecting %d\n"
> "got %d", to_read, length);
> cifs_reconnect(server);
> + rec = true;
> total_read = -EAGAIN;
> break;
> }
> }
> + if (was_reconnect)
> + *was_reconnect = rec;
> return total_read;
> }
>
> @@ -604,7 +611,7 @@ cifs_read_from_socket(struct TCP_Server_Info *server, char *buf,
> iov.iov_base = buf;
> iov.iov_len = to_read;
>
> - return cifs_readv_from_socket(server, &iov, 1, to_read);
> + return cifs_readv_from_socket(server, &iov, 1, to_read, NULL);
> }
>
> static bool
> diff --git a/fs/cifs/file.c b/fs/cifs/file.c
> index d5f66ba..d7f5742 100644
> --- a/fs/cifs/file.c
> +++ b/fs/cifs/file.c
> @@ -2865,7 +2865,8 @@ cifs_uncached_readv_complete(struct work_struct *work)
>
> static int
> cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
> - struct cifs_readdata *rdata, unsigned int len)
> + struct cifs_readdata *rdata, unsigned int len,
> + bool *was_reconnect)
> {
> int total_read = 0, result = 0;
> unsigned int i;
> @@ -2900,7 +2901,8 @@ cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
> continue;
> }
>
> - result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
> + result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len,
> + was_reconnect);
> kunmap(page);
> if (result < 0)
> break;
> @@ -2908,7 +2910,7 @@ cifs_uncached_read_into_pages(struct TCP_Server_Info *server,
> total_read += result;
> }
>
> - return total_read > 0 && result != -EAGAIN ? total_read : result;
> + return total_read > 0 ? total_read : result;
> }
>
> static int
> @@ -3287,7 +3289,8 @@ cifs_readv_complete(struct work_struct *work)
>
> static int
> cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
> - struct cifs_readdata *rdata, unsigned int len)
> + struct cifs_readdata *rdata, unsigned int len,
> + bool *was_reconnect)
> {
> int total_read = 0, result = 0;
> unsigned int i;
> @@ -3350,7 +3353,8 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
> continue;
> }
>
> - result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len);
> + result = cifs_readv_from_socket(server, &iov, 1, iov.iov_len,
> + was_reconnect);
> kunmap(page);
> if (result < 0)
> break;
> @@ -3358,7 +3362,7 @@ cifs_readpages_read_into_pages(struct TCP_Server_Info *server,
> total_read += result;
> }
>
> - return total_read > 0 && result != -EAGAIN ? total_read : result;
> + return total_read > 0 ? total_read : result;
> }
>
> static int
Ugh.
It seems like we ought to instead just designate a different error code
than -EAGAIN (-ECONNABORTED?) for the case where a reconnect is needed,
and fix up the callers to handle that appropriately. There aren't that
many callers of cifs_readv_from_socket...
--
Jeff Layton <jlayton@xxxxxxxxx>
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