litmus-rt-ext-res.git - LITMUS^RT with extended reservations for Forbidden Zones paper @ RTAS'20

diff options

author	Faisal Latif <faisal.latif@intel.com>	2009-06-23 01:53:28 -0400
committer	Roland Dreier <rolandd@cisco.com>	2009-06-23 01:53:28 -0400
commit	68237a0ff84503270373c39229be83e865ea08d4 (patch)
tree	70cea4414290c7799704f0beea6cb3894036d380
parent	66388d67a0d7bf39735650de54e42064d1af8b62 (diff)

RDMA/nes: Fix FIN state handling under error conditions

During cluster testing, one QP was not closed, as FIN is not handled properly when its rexmit count expires or in some cases when RST is is received after sending FIN. The reason is that the cm_id does not get decremented under these conditions. Signed-off-by: Faisal Latif <faisal.latif@intel.com> Signed-off-by: Roland Dreier <rolandd@cisco.com>

Diffstat

-rw-r--r--

drivers/infiniband/hw/nes/nes_cm.c

1 files changed, 5 insertions, 3 deletions

 static void nes_retrans_expired(struct nes_cm_node *cm_node)
 {
+        struct iw_cm_id *cm_id = cm_node->cm_id;
         switch (cm_node->state) {
         case NES_CM_STATE_SYN_RCVD:
         case NES_CM_STATE_CLOSING:
                 break;
         case NES_CM_STATE_LAST_ACK:
         case NES_CM_STATE_FIN_WAIT1:
-        case NES_CM_STATE_MPAREJ_RCVD:
+                if (cm_node->cm_id)
+                        cm_id->rem_ref(cm_id);
+                cm_node->state = NES_CM_STATE_CLOSED;
                 send_reset(cm_node, NULL);
                 break;
         default:
         case NES_CM_STATE_CLOSED:
                 drop_packet(skb);
                 break;
+        case NES_CM_STATE_FIN_WAIT1:
         case NES_CM_STATE_LAST_ACK:
                 cm_node->cm_id->rem_ref(cm_node->cm_id);
         case NES_CM_STATE_TIME_WAIT:
                 rem_ref_cm_node(cm_node->cm_core, cm_node);
                 drop_packet(skb);
                 break;
-        case NES_CM_STATE_FIN_WAIT1:
-                nes_debug(NES_DBG_CM, "Bad state %s[%u]\n", __func__, __LINE__);
         default:
                 drop_packet(skb);
                 break;

\documentclass{article} \def\version{$Id: cdrom-standard.tex,v 1.9 1997/12/28 15:42:49 david Exp $} \newcommand{\newsection}[1]{\newpage\section{#1}} \evensidemargin=0pt \oddsidemargin=0pt \topmargin=-\headheight \advance\topmargin by -\headsep \textwidth=15.99cm \textheight=24.62cm % normal A4, 1'' margin \def\linux{{\sc Linux}} \def\cdrom{{\sc cd-rom}} \def\UCD{{\sc Uniform cd-rom Driver}} \def\cdromc{{\tt {cdrom.c}}} \def\cdromh{{\tt {cdrom.h}}} \def\fo{\sl} % foreign words \def\ie{{\fo i.e.}} \def\eg{{\fo e.g.}} \everymath{\it} \everydisplay{\it} \catcode `\_=\active \def_{\_\penalty100 } \catcode`\<=\active \def<#1>{{\langle\hbox{\rm#1}\rangle}} \begin{document} \title{A \linux\ \cdrom\ standard} \author{David van Leeuwen\\{\normalsize\tt david@ElseWare.cistron.nl} \\{\footnotesize updated by Erik Andersen {\tt(andersee@debian.org)}} \\{\footnotesize updated by Jens Axboe {\tt(axboe@image.dk)}}} \date{12 March 1999} \maketitle \newsection{Introduction} \linux\ is probably the Unix-like operating system that supports the widest variety of hardware devices. The reasons for this are presumably \begin{itemize} \item The large list of hardware devices available for the many platforms that \linux\ now supports (\ie, i386-PCs, Sparc Suns, etc.) \item The open design of the operating system, such that anybody can write a driver for \linux. \item There is plenty of source code around as examples of how to write a driver. \end{itemize} The openness of \linux, and the many different types of available hardware has allowed \linux\ to support many different hardware devices. Unfortunately, the very openness that has allowed \linux\ to support all these different devices has also allowed the behavior of each device driver to differ significantly from one device to another. This divergence of behavior has been very significant for \cdrom\ devices; the way a particular drive reacts to a `standard' $ioctl()$ call varies greatly from one device driver to another. To avoid making their drivers totally inconsistent, the writers of \linux\ \cdrom\ drivers generally created new device drivers by understanding, copying, and then changing an existing one. Unfortunately, this practice did not maintain uniform behavior across all the \linux\ \cdrom\ drivers. This document describes an effort to establish Uniform behavior across all the different \cdrom\ device drivers for \linux. This document also defines the various $ioctl$s, and how the low-level \cdrom\ device drivers should implement them. Currently (as of the \linux\ 2.1.$x$ development kernels) several low-level \cdrom\ device drivers, including both IDE/ATAPI and SCSI, now use this Uniform interface. When the \cdrom\ was developed, the interface between the \cdrom\ drive and the computer was not specified in the standards. As a result, many different \cdrom\ interfaces were developed. Some of them had their own proprietary design (Sony, Mitsumi, Panasonic, Philips), other manufacturers adopted an existing electrical interface and changed the functionality (CreativeLabs/SoundBlaster, Teac, Funai) or simply adapted their drives to one or more of the already existing electrical interfaces (Aztech, Sanyo, Funai, Vertos, Longshine, Optics Storage and most of the `NoName' manufacturers). In cases where a new drive really brought its own interface or used its own command set and flow control scheme, either a separate driver had to be written, or an existing driver had to be enhanced. History has delivered us \cdrom\ support for many of these different interfaces. Nowadays, almost all new \cdrom\ drives are either IDE/ATAPI or SCSI, and it is very unlikely that any manufacturer will create a new interface. Even finding drives for the old proprietary interfaces is getting difficult. When (in the 1.3.70's) I looked at the existing software interface, which was expressed through \cdromh, it appeared to be a rather wild set of commands and data formats.\footnote{I cannot recollect what kernel version I looked at, then, presumably 1.2.13 and 1.3.34---the latest kernel that I was indirectly involved in.} It seemed that many features of the software interface had been added to accommodate the capabilities of a particular drive, in an {\fo ad hoc\/} manner. More importantly, it appeared that the behavior of the `standard' commands was different for most of the different drivers: \eg, some drivers close the tray if an $open()$ call occurs when the tray is open, while others do not. Some drivers lock the door upon opening the device, to prevent an incoherent file system, but others don't, to allow software ejection. Undoubtedly, the capabilities of the different drives vary, but even when two drives have the same capability their drivers' behavior was usually different. I decided to start a discussion on how to make all the \linux\ \cdrom\ drivers behave more uniformly. I began by contacting the developers of the many \cdrom\ drivers found in the \linux\ kernel. Their reactions encouraged me to write the \UCD\ which this document is intended to describe. The implementation of the \UCD\ is in the file \cdromc. This driver is intended to be an additional software layer that sits on top of the low-level device drivers for each \cdrom\ drive. By adding this additional layer, it is possible to have all the different \cdrom\ devices behave {\em exactly\/} the same (insofar as the underlying hardware will allow). The goal of the \UCD\ is {\em not\/} to alienate driver developers who have not yet taken steps to support this effort. The goal of \UCD\ is simply to give people writing application programs for \cdrom\ drives {\em one\/} \linux\ \cdrom\ interface with consistent behavior for all \cdrom\ devices. In addition, this also provides a consistent interface between the low-level device driver code and the \linux\ kernel. Care is taken that 100\,\% compatibility exists with the data structures and programmer's interface defined in \cdromh. This guide was written to help \cdrom\ driver developers adapt their code to use the \UCD\ code defined in \cdromc. Personally, I think that the most important hardware interfaces are the IDE/ATAPI drives and, of course, the SCSI drives, but as prices of hardware drop continuously, it is also likely that people may have more than one \cdrom\ drive, possibly of mixed types. It is important that these drives behave in the same way. In December 1994, one of the cheapest \cdrom\ drives was a Philips cm206, a double-speed proprietary drive. In the months that I was busy writing a \linux\ driver for it, proprietary drives became obsolete and IDE/ATAPI drives became the standard. At the time of the last update to this document (November 1997) it is becoming difficult to even {\em find} anything less than a 16 speed \cdrom\ drive, and 24 speed drives are common. \newsection{Standardizing through another software level} \label{cdrom.c} At the time this document was conceived, all drivers directly implemented the \cdrom\ $ioctl()$ calls through their own routines. This led to the danger of different drivers forgetting to do important things like checking that the user was giving the driver valid data. More importantly, this led to the divergence of behavior, which has already been discussed. For this reason, the \UCD\ was created to enforce consistent \cdrom\ drive behavior, and to provide a common set of services to the various low-level \cdrom\ device drivers. The \UCD\ now provides another software-level, that separates the $ioctl()$ and $open()$ implementation from the actual hardware implementation. Note that this effort has made few changes which will affect a user's application programs. The greatest change involved moving the contents of the various low-level \cdrom\ drivers' header files to the kernel's cdrom directory. This was done to help ensure that the user is only presented with only one cdrom interface, the interface defined in \cdromh. \cdrom\ drives are specific enough (\ie, different from other block-devices such as floppy or hard disc drives), to define a set of common {\em \cdrom\ device operations}, $<cdrom-device>_dops$. These operations are different from the classical block-device file operations, $<block-device>_fops$. The routines for the \UCD\ interface level are implemented in the file \cdromc. In this file, the \UCD\ interfaces with the kernel as a block device by registering the following general $struct\ file_operations$: $$ \halign{$#$\ \hfil&$#$\ \hfil&$/*$ \rm# $*/$\hfil\cr struct& file_operations\ cdrom_fops = \{\hidewidth\cr &NULL, & lseek \cr &block_read, & read---general block-dev read \cr &block_write, & write---general block-dev write \cr &NULL, & readdir \cr &NULL, & select \cr &cdrom_ioctl, & ioctl \cr &NULL, & mmap \cr &cdrom_open, & open \cr &cdrom_release, & release \cr &NULL, & fsync \cr &NULL, & fasync \cr &cdrom_media_changed, & media change \cr &NULL & revalidate \cr \};\cr } $$ Every active \cdrom\ device shares this $struct$. The routines declared above are all implemented in \cdromc, since this file is the place where the behavior of all \cdrom-devices is defined and standardized. The actual interface to the various types of \cdrom\ hardware is still performed by various low-level \cdrom-device drivers. These routines simply implement certain {\em capabilities\/} that are common to all \cdrom\ (and really, all removable-media devices). Registration of a low-level \cdrom\ device driver is now done through the general routines in \cdromc, not through the Virtual File System (VFS) any more. The interface implemented in \cdromc\ is carried out through two general structures that contain information about the capabilities of the driver, and the specific drives on which the driver operates. The structures are: \begin{description} \item[$cdrom_device_ops$] This structure contains information about the low-level driver for a \cdrom\ device. This structure is conceptually connected to the major number of the device (although some drivers may have different major numbers, as is the case for the IDE driver). \item[$cdrom_device_info$] This structure contains information about a particular \cdrom\ drive, such as its device name, speed, etc. This structure is conceptually connected to the minor number of the device. \end{description} Registering a particular \cdrom\ drive with the \UCD\ is done by the low-level device driver though a call to: $$register_cdrom(struct\ cdrom_device_info * <device>_info) $$ The device information structure, $<device>_info$, contains all the information needed for the kernel to interface with the low-level \cdrom\ device driver. One of the most important entries in this structure is a pointer to the $cdrom_device_ops$ structure of the low-level driver. The device operations structure, $cdrom_device_ops$, contains a list of pointers to the functions which are implemented in the low-level device driver. When \cdromc\ accesses a \cdrom\ device, it does it through the functions in this structure. It is impossible to know all the capabilities of future \cdrom\ drives, so it is expected that this list may need to be expanded from time to time as new technologies are developed. For example, CD-R and CD-R/W drives are beginning to become popular, and support will soon need to be added for them. For now, the current $struct$ is: $$ \halign{$#$\ \hfil&$#$\ \hfil&\hbox to 10em{$#$\hss}& $/*$ \rm# $*/$\hfil\cr struct& cdrom_device_ops\ \{ \hidewidth\cr &int& (* open)(struct\ cdrom_device_info *, int)\cr &void& (* release)(struct\ cdrom_device_info *);\cr &int& (* drive_status)(struct\ cdrom_device_info *, int);\cr &int& (* media_changed)(struct\ cdrom_device_info *, int);\cr &int& (* tray_move)(struct\ cdrom_device_info *, int);\cr &int& (* lock_door)(struct\ cdrom_device_info *, int);\cr &int& (* select_speed)(struct\ cdrom_device_info *, int);\cr &int& (* select_disc)(struct\ cdrom_device_info *, int);\cr &int& (* get_last_session) (struct\ cdrom_device_info *, struct\ cdrom_multisession *{});\cr &int& (* get_mcn)(struct\ cdrom_device_info *, struct\ cdrom_mcn *{});\cr &int& (* reset)(struct\ cdrom_device_info *);\cr &int& (* audio_ioctl)(struct\ cdrom_device_info *, unsigned\ int, void *{});\cr &int& (* dev_ioctl)(struct\ cdrom_device_info *, unsigned\ int, unsigned\ long);\cr \noalign{\medskip} &const\ int& capability;& capability flags \cr &int& n_minors;& number of active minor devices \cr \};\cr } $$ When a low-level device driver implements one of these capabilities,


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