5557 Commits (38e23c95f92a84fb8505a9f572b8a209c9c372c1)

Author	SHA1	Message	Date
Henrique de Moraes Holschuh	bee4cd9b9e	thinkpad-acpi: enhanced debugging messages for rfkill subdrivers ... Enhance debugging messages for all rfkill subdrivers in thinkpad-acpi. Also, log a warning if the deprecated sysfs attributes are in use. These attributes are going to be removed sometime in 2010. There is an user-visible side-effect: we now coalesce attempts to enable/disable bluetooth or WWAN in the procfs interface, instead of hammering the firmware with multiple requests. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>	16 years ago
Henrique de Moraes Holschuh	a4d5effcc7	thinkpad-acpi: restrict access to some firmware LEDs ... Some of the ThinkPad LEDs indicate critical conditions that can cause data loss or cause hardware damage when ignored (e.g. force-ejecting a powered up bay; ignoring a failing battery, or empty battery; force- undocking with the dock buses still active, etc). On almost all ThinkPads, LED access is write-only, and the firmware usually does fire-and-forget signaling on them, so you effectively lose whatever message the firmware was trying to convey to the user when you override the LED state, without any chance to restore it. Restrict access to all LEDs that can convey important alarms, or that could mislead the user into incorrectly operating the hardware. This will make the Lenovo engineers less unhappy about the whole issue. Allow users that really want it to still control all LEDs, it is the unaware user that we have to worry about. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>	16 years ago
Henrique de Moraes Holschuh	2586d5663d	thinkpad-acpi: remove HKEY disable functionality ... The HKEY disable functionality basically cripples the entire event model of the ThinkPad firmware and of the thinkpad-acpi driver. Remove this functionality from the driver. HKEY must be enabled at all times while thinkpad-acpi is loaded, and disabled otherwise. For sysfs, according to the sysfs ABI and the thinkpad-acpi sysfs rules of engagement, we will just remove the attributes. This will be done in two stages: disable their function now, after two kernel releases, remove the attributes. For procfs, we call WARN(). If nothing triggers it, I will simply remove the enable/disable commands entirely in the future along with the sysfs attributes. I don't expect much, if any fallout from this. There really isn't any reason to mess with hotkey_enable or with the enable/disable commands to /proc/acpi/ibm/hotkey, and this has been true for years... Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>	16 years ago
Henrique de Moraes Holschuh	73a94d86a8	thinkpad-acpi: add new debug helpers and warn of deprecated atts ... Add a debug helper that discloses the TGID of the userspace task attempting to access the driver. This is highly useful when dealing with bug reports, since often the user has no idea that some userspace application is accessing thinkpad-acpi... Also add a helper to log warnings about sysfs attributes that are deprecated. Use the new helpers to issue deprecation warnings for bluetooth_enable and wwan_enabled, that have been deprecated for a while, now. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>	16 years ago
Henrique de Moraes Holschuh	078ac19ed8	thinkpad-acpi: documentation cleanup ... Some cleanups to the documentation of the driver. Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br> Signed-off-by: Len Brown <len.brown@intel.com>	16 years ago
Benny Halevy	3ef1728898	nfsd41: Documentation/filesystems/nfs41-server.txt ... Initial nfs41 server write up describing the status of the linux server implementation. [nfsd41: document unenforced nfs41 compound ordering rules.] [get rid of CONFIG_NFSD_V4_1] Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>	16 years ago
Alan Cox	04c860c188	LANANA: Change of management and resync ... Bring the devices.txt back into some relationship with reality. Update the documentation a bit. Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Evgeniy Polyakov	b8523c40d5	Staging: pohmelfs: documentation. ... This patch includes POHMELFS design and implementation description. Separate file includes mount options, default parameters and usage examples. Signed-off-by: Eveniy Polyakov <zbr@ioremap.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>	16 years ago
David Howells	9ae326a690	CacheFiles: A cache that backs onto a mounted filesystem ... Add an FS-Cache cache-backend that permits a mounted filesystem to be used as a backing store for the cache. CacheFiles uses a userspace daemon to do some of the cache management - such as reaping stale nodes and culling. This is called cachefilesd and lives in /sbin. The source for the daemon can be downloaded from: http://people.redhat.com/~dhowells/cachefs/cachefilesd.c And an example configuration from: http://people.redhat.com/~dhowells/cachefs/cachefilesd.conf The filesystem and data integrity of the cache are only as good as those of the filesystem providing the backing services. Note that CacheFiles does not attempt to journal anything since the journalling interfaces of the various filesystems are very specific in nature. CacheFiles creates a misc character device - "/dev/cachefiles" - that is used to communication with the daemon. Only one thing may have this open at once, and whilst it is open, a cache is at least partially in existence. The daemon opens this and sends commands down it to control the cache. CacheFiles is currently limited to a single cache. CacheFiles attempts to maintain at least a certain percentage of free space on the filesystem, shrinking the cache by culling the objects it contains to make space if necessary - see the "Cache Culling" section. This means it can be placed on the same medium as a live set of data, and will expand to make use of spare space and automatically contract when the set of data requires more space. ============ REQUIREMENTS ============ The use of CacheFiles and its daemon requires the following features to be available in the system and in the cache filesystem: - dnotify. - extended attributes (xattrs). - openat() and friends. - bmap() support on files in the filesystem (FIBMAP ioctl). - The use of bmap() to detect a partial page at the end of the file. It is strongly recommended that the "dir_index" option is enabled on Ext3 filesystems being used as a cache. ============= CONFIGURATION ============= The cache is configured by a script in /etc/cachefilesd.conf. These commands set up cache ready for use. The following script commands are available: (*) brun <N>% (*) bcull <N>% (*) bstop <N>% (*) frun <N>% (*) fcull <N>% (*) fstop <N>% Configure the culling limits. Optional. See the section on culling The defaults are 7% (run), 5% (cull) and 1% (stop) respectively. The commands beginning with a 'b' are file space (block) limits, those beginning with an 'f' are file count limits. (*) dir <path> Specify the directory containing the root of the cache. Mandatory. (*) tag <name> Specify a tag to FS-Cache to use in distinguishing multiple caches. Optional. The default is "CacheFiles". (*) debug <mask> Specify a numeric bitmask to control debugging in the kernel module. Optional. The default is zero (all off). The following values can be OR'd into the mask to collect various information: 1 Turn on trace of function entry (_enter() macros) 2 Turn on trace of function exit (_leave() macros) 4 Turn on trace of internal debug points (_debug()) This mask can also be set through sysfs, eg: echo 5 >/sys/modules/cachefiles/parameters/debug ================== STARTING THE CACHE ================== The cache is started by running the daemon. The daemon opens the cache device, configures the cache and tells it to begin caching. At that point the cache binds to fscache and the cache becomes live. The daemon is run as follows: /sbin/cachefilesd [-d]* [-s] [-n] [-f <configfile>] The flags are: (*) -d Increase the debugging level. This can be specified multiple times and is cumulative with itself. (*) -s Send messages to stderr instead of syslog. (*) -n Don't daemonise and go into background. (*) -f <configfile> Use an alternative configuration file rather than the default one. =============== THINGS TO AVOID =============== Do not mount other things within the cache as this will cause problems. The kernel module contains its own very cut-down path walking facility that ignores mountpoints, but the daemon can't avoid them. Do not create, rename or unlink files and directories in the cache whilst the cache is active, as this may cause the state to become uncertain. Renaming files in the cache might make objects appear to be other objects (the filename is part of the lookup key). Do not change or remove the extended attributes attached to cache files by the cache as this will cause the cache state management to get confused. Do not create files or directories in the cache, lest the cache get confused or serve incorrect data. Do not chmod files in the cache. The module creates things with minimal permissions to prevent random users being able to access them directly. ============= CACHE CULLING ============= The cache may need culling occasionally to make space. This involves discarding objects from the cache that have been used less recently than anything else. Culling is based on the access time of data objects. Empty directories are culled if not in use. Cache culling is done on the basis of the percentage of blocks and the percentage of files available in the underlying filesystem. There are six "limits": (*) brun (*) frun If the amount of free space and the number of available files in the cache rises above both these limits, then culling is turned off. (*) bcull (*) fcull If the amount of available space or the number of available files in the cache falls below either of these limits, then culling is started. (*) bstop (*) fstop If the amount of available space or the number of available files in the cache falls below either of these limits, then no further allocation of disk space or files is permitted until culling has raised things above these limits again. These must be configured thusly: 0 <= bstop < bcull < brun < 100 0 <= fstop < fcull < frun < 100 Note that these are percentages of available space and available files, and do _not_ appear as 100 minus the percentage displayed by the "df" program. The userspace daemon scans the cache to build up a table of cullable objects. These are then culled in least recently used order. A new scan of the cache is started as soon as space is made in the table. Objects will be skipped if their atimes have changed or if the kernel module says it is still using them. =============== CACHE STRUCTURE =============== The CacheFiles module will create two directories in the directory it was given: (*) cache/ (*) graveyard/ The active cache objects all reside in the first directory. The CacheFiles kernel module moves any retired or culled objects that it can't simply unlink to the graveyard from which the daemon will actually delete them. The daemon uses dnotify to monitor the graveyard directory, and will delete anything that appears therein. The module represents index objects as directories with the filename "I..." or "J...". Note that the "cache/" directory is itself a special index. Data objects are represented as files if they have no children, or directories if they do. Their filenames all begin "D..." or "E...". If represented as a directory, data objects will have a file in the directory called "data" that actually holds the data. Special objects are similar to data objects, except their filenames begin "S..." or "T...". If an object has children, then it will be represented as a directory. Immediately in the representative directory are a collection of directories named for hash values of the child object keys with an '@' prepended. Into this directory, if possible, will be placed the representations of the child objects: INDEX INDEX INDEX DATA FILES ========= ========== ================================= ================ cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400 cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400/@75/Es0g000w...DB1ry cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400/@75/Es0g000w...N22ry cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400/@75/Es0g000w...FP1ry If the key is so long that it exceeds NAME_MAX with the decorations added on to it, then it will be cut into pieces, the first few of which will be used to make a nest of directories, and the last one of which will be the objects inside the last directory. The names of the intermediate directories will have '+' prepended: J1223/@23/+xy...z/+kl...m/Epqr Note that keys are raw data, and not only may they exceed NAME_MAX in size, they may also contain things like '/' and NUL characters, and so they may not be suitable for turning directly into a filename. To handle this, CacheFiles will use a suitably printable filename directly and "base-64" encode ones that aren't directly suitable. The two versions of object filenames indicate the encoding: OBJECT TYPE PRINTABLE ENCODED =============== =============== =============== Index "I..." "J..." Data "D..." "E..." Special "S..." "T..." Intermediate directories are always "@" or "+" as appropriate. Each object in the cache has an extended attribute label that holds the object type ID (required to distinguish special objects) and the auxiliary data from the netfs. The latter is used to detect stale objects in the cache and update or retire them. Note that CacheFiles will erase from the cache any file it doesn't recognise or any file of an incorrect type (such as a FIFO file or a device file). ========================== SECURITY MODEL AND SELINUX ========================== CacheFiles is implemented to deal properly with the LSM security features of the Linux kernel and the SELinux facility. One of the problems that CacheFiles faces is that it is generally acting on behalf of a process, and running in that process's context, and that includes a security context that is not appropriate for accessing the cache - either because the files in the cache are inaccessible to that process, or because if the process creates a file in the cache, that file may be inaccessible to other processes. The way CacheFiles works is to temporarily change the security context (fsuid, fsgid and actor security label) that the process acts as - without changing the security context of the process when it the target of an operation performed by some other process (so signalling and suchlike still work correctly). When the CacheFiles module is asked to bind to its cache, it: (1) Finds the security label attached to the root cache directory and uses that as the security label with which it will create files. By default, this is: cachefiles_var_t (2) Finds the security label of the process which issued the bind request (presumed to be the cachefilesd daemon), which by default will be: cachefilesd_t and asks LSM to supply a security ID as which it should act given the daemon's label. By default, this will be: cachefiles_kernel_t SELinux transitions the daemon's security ID to the module's security ID based on a rule of this form in the policy. type_transition <daemon's-ID> kernel_t : process <module's-ID>; For instance: type_transition cachefilesd_t kernel_t : process cachefiles_kernel_t; The module's security ID gives it permission to create, move and remove files and directories in the cache, to find and access directories and files in the cache, to set and access extended attributes on cache objects, and to read and write files in the cache. The daemon's security ID gives it only a very restricted set of permissions: it may scan directories, stat files and erase files and directories. It may not read or write files in the cache, and so it is precluded from accessing the data cached therein; nor is it permitted to create new files in the cache. There are policy source files available in: http://people.redhat.com/~dhowells/fscache/cachefilesd-0.8.tar.bz2 and later versions. In that tarball, see the files: cachefilesd.te cachefilesd.fc cachefilesd.if They are built and installed directly by the RPM. If a non-RPM based system is being used, then copy the above files to their own directory and run: make -f /usr/share/selinux/devel/Makefile semodule -i cachefilesd.pp You will need checkpolicy and selinux-policy-devel installed prior to the build. By default, the cache is located in /var/fscache, but if it is desirable that it should be elsewhere, than either the above policy files must be altered, or an auxiliary policy must be installed to label the alternate location of the cache. For instructions on how to add an auxiliary policy to enable the cache to be located elsewhere when SELinux is in enforcing mode, please see: /usr/share/doc/cachefilesd-*/move-cache.txt When the cachefilesd rpm is installed; alternatively, the document can be found in the sources. ================== A NOTE ON SECURITY ================== CacheFiles makes use of the split security in the task_struct. It allocates its own task_security structure, and redirects current->act_as to point to it when it acts on behalf of another process, in that process's context. The reason it does this is that it calls vfs_mkdir() and suchlike rather than bypassing security and calling inode ops directly. Therefore the VFS and LSM may deny the CacheFiles access to the cache data because under some circumstances the caching code is running in the security context of whatever process issued the original syscall on the netfs. Furthermore, should CacheFiles create a file or directory, the security parameters with that object is created (UID, GID, security label) would be derived from that process that issued the system call, thus potentially preventing other processes from accessing the cache - including CacheFiles's cache management daemon (cachefilesd). What is required is to temporarily override the security of the process that issued the system call. We can't, however, just do an in-place change of the security data as that affects the process as an object, not just as a subject. This means it may lose signals or ptrace events for example, and affects what the process looks like in /proc. So CacheFiles makes use of a logical split in the security between the objective security (task->sec) and the subjective security (task->act_as). The objective security holds the intrinsic security properties of a process and is never overridden. This is what appears in /proc, and is what is used when a process is the target of an operation by some other process (SIGKILL for example). The subjective security holds the active security properties of a process, and may be overridden. This is not seen externally, and is used whan a process acts upon another object, for example SIGKILLing another process or opening a file. LSM hooks exist that allow SELinux (or Smack or whatever) to reject a request for CacheFiles to run in a context of a specific security label, or to create files and directories with another security label. This documentation is added by the patch to: Documentation/filesystems/caching/cachefiles.txt Signed-Off-By: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>	16 years ago
David Howells	952efe7b78	FS-Cache: Add and document asynchronous operation handling ... Add and document asynchronous operation handling for use by FS-Cache's data storage and retrieval routines. The following documentation is added to: Documentation/filesystems/caching/operations.txt ================================ ASYNCHRONOUS OPERATIONS HANDLING ================================ ======== OVERVIEW ======== FS-Cache has an asynchronous operations handling facility that it uses for its data storage and retrieval routines. Its operations are represented by fscache_operation structs, though these are usually embedded into some other structure. This facility is available to and expected to be be used by the cache backends, and FS-Cache will create operations and pass them off to the appropriate cache backend for completion. To make use of this facility, <linux/fscache-cache.h> should be #included. =============================== OPERATION RECORD INITIALISATION =============================== An operation is recorded in an fscache_operation struct: struct fscache_operation { union { struct work_struct fast_work; struct slow_work slow_work; }; unsigned long flags; fscache_operation_processor_t processor; ... }; Someone wanting to issue an operation should allocate something with this struct embedded in it. They should initialise it by calling: void fscache_operation_init(struct fscache_operation *op, fscache_operation_release_t release); with the operation to be initialised and the release function to use. The op->flags parameter should be set to indicate the CPU time provision and the exclusivity (see the Parameters section). The op->fast_work, op->slow_work and op->processor flags should be set as appropriate for the CPU time provision (see the Parameters section). FSCACHE_OP_WAITING may be set in op->flags prior to each submission of the operation and waited for afterwards. ========== PARAMETERS ========== There are a number of parameters that can be set in the operation record's flag parameter. There are three options for the provision of CPU time in these operations: (1) The operation may be done synchronously (FSCACHE_OP_MYTHREAD). A thread may decide it wants to handle an operation itself without deferring it to another thread. This is, for example, used in read operations for calling readpages() on the backing filesystem in CacheFiles. Although readpages() does an asynchronous data fetch, the determination of whether pages exist is done synchronously - and the netfs does not proceed until this has been determined. If this option is to be used, FSCACHE_OP_WAITING must be set in op->flags before submitting the operation, and the operating thread must wait for it to be cleared before proceeding: wait_on_bit(&op->flags, FSCACHE_OP_WAITING, fscache_wait_bit, TASK_UNINTERRUPTIBLE); (2) The operation may be fast asynchronous (FSCACHE_OP_FAST), in which case it will be given to keventd to process. Such an operation is not permitted to sleep on I/O. This is, for example, used by CacheFiles to copy data from a backing fs page to a netfs page after the backing fs has read the page in. If this option is used, op->fast_work and op->processor must be initialised before submitting the operation: INIT_WORK(&op->fast_work, do_some_work); (3) The operation may be slow asynchronous (FSCACHE_OP_SLOW), in which case it will be given to the slow work facility to process. Such an operation is permitted to sleep on I/O. This is, for example, used by FS-Cache to handle background writes of pages that have just been fetched from a remote server. If this option is used, op->slow_work and op->processor must be initialised before submitting the operation: fscache_operation_init_slow(op, processor) Furthermore, operations may be one of two types: (1) Exclusive (FSCACHE_OP_EXCLUSIVE). Operations of this type may not run in conjunction with any other operation on the object being operated upon. An example of this is the attribute change operation, in which the file being written to may need truncation. (2) Shareable. Operations of this type may be running simultaneously. It's up to the operation implementation to prevent interference between other operations running at the same time. ========= PROCEDURE ========= Operations are used through the following procedure: (1) The submitting thread must allocate the operation and initialise it itself. Normally this would be part of a more specific structure with the generic op embedded within. (2) The submitting thread must then submit the operation for processing using one of the following two functions: int fscache_submit_op(struct fscache_object *object, struct fscache_operation *op); int fscache_submit_exclusive_op(struct fscache_object *object, struct fscache_operation *op); The first function should be used to submit non-exclusive ops and the second to submit exclusive ones. The caller must still set the FSCACHE_OP_EXCLUSIVE flag. If successful, both functions will assign the operation to the specified object and return 0. -ENOBUFS will be returned if the object specified is permanently unavailable. The operation manager will defer operations on an object that is still undergoing lookup or creation. The operation will also be deferred if an operation of conflicting exclusivity is in progress on the object. If the operation is asynchronous, the manager will retain a reference to it, so the caller should put their reference to it by passing it to: void fscache_put_operation(struct fscache_operation *op); (3) If the submitting thread wants to do the work itself, and has marked the operation with FSCACHE_OP_MYTHREAD, then it should monitor FSCACHE_OP_WAITING as described above and check the state of the object if necessary (the object might have died whilst the thread was waiting). When it has finished doing its processing, it should call fscache_put_operation() on it. (4) The operation holds an effective lock upon the object, preventing other exclusive ops conflicting until it is released. The operation can be enqueued for further immediate asynchronous processing by adjusting the CPU time provisioning option if necessary, eg: op->flags &= ~FSCACHE_OP_TYPE; op->flags |= ~FSCACHE_OP_FAST; and calling: void fscache_enqueue_operation(struct fscache_operation *op) This can be used to allow other things to have use of the worker thread pools. ===================== ASYNCHRONOUS CALLBACK ===================== When used in asynchronous mode, the worker thread pool will invoke the processor method with a pointer to the operation. This should then get at the container struct by using container_of(): static void fscache_write_op(struct fscache_operation *_op) { struct fscache_storage *op = container_of(_op, struct fscache_storage, op); ... } The caller holds a reference on the operation, and will invoke fscache_put_operation() when the processor function returns. The processor function is at liberty to call fscache_enqueue_operation() or to take extra references. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>	16 years ago
David Howells	36c9559022	FS-Cache: Object management state machine ... Implement the cache object management state machine. The following documentation is added to illuminate the working of this state machine. It will also be added as: Documentation/filesystems/caching/object.txt ==================================================== IN-KERNEL CACHE OBJECT REPRESENTATION AND MANAGEMENT ==================================================== ============== REPRESENTATION ============== FS-Cache maintains an in-kernel representation of each object that a netfs is currently interested in. Such objects are represented by the fscache_cookie struct and are referred to as cookies. FS-Cache also maintains a separate in-kernel representation of the objects that a cache backend is currently actively caching. Such objects are represented by the fscache_object struct. The cache backends allocate these upon request, and are expected to embed them in their own representations. These are referred to as objects. There is a 1:N relationship between cookies and objects. A cookie may be represented by multiple objects - an index may exist in more than one cache - or even by no objects (it may not be cached). Furthermore, both cookies and objects are hierarchical. The two hierarchies correspond, but the cookies tree is a superset of the union of the object trees of multiple caches: NETFS INDEX TREE : CACHE 1 : CACHE 2 : : : +-----------+ : +----------->| IObject | : +-----------+ | : +-----------+ : | ICookie |-------+ : | : +-----------+ | : | : +-----------+ | +------------------------------>| IObject | | : | : +-----------+ | : V : | | : +-----------+ : | V +----------->| IObject | : | +-----------+ | : +-----------+ : | | ICookie |-------+ : | : V +-----------+ | : | : +-----------+ | +------------------------------>| IObject | +-----+-----+ : | : +-----------+ | | : | : | V | : V : | +-----------+ | : +-----------+ : | | ICookie |------------------------->| IObject | : | +-----------+ | : +-----------+ : | | V : | : V | +-----------+ : | : +-----------+ | | ICookie |-------------------------------->| IObject | | +-----------+ : | : +-----------+ V | : V : | +-----------+ | : +-----------+ : | | DCookie |------------------------->| DObject | : | +-----------+ | : +-----------+ : | | : : | +-------+-------+ : : | | | : : | V V : : V +-----------+ +-----------+ : : +-----------+ | DCookie | | DCookie |------------------------>| DObject | +-----------+ +-----------+ : : +-----------+ : : In the above illustration, ICookie and IObject represent indices and DCookie and DObject represent data storage objects. Indices may have representation in multiple caches, but currently, non-index objects may not. Objects of any type may also be entirely unrepresented. As far as the netfs API goes, the netfs is only actually permitted to see pointers to the cookies. The cookies themselves and any objects attached to those cookies are hidden from it. =============================== OBJECT MANAGEMENT STATE MACHINE =============================== Within FS-Cache, each active object is managed by its own individual state machine. The state for an object is kept in the fscache_object struct, in object->state. A cookie may point to a set of objects that are in different states. Each state has an action associated with it that is invoked when the machine wakes up in that state. There are four logical sets of states: (1) Preparation: states that wait for the parent objects to become ready. The representations are hierarchical, and it is expected that an object must be created or accessed with respect to its parent object. (2) Initialisation: states that perform lookups in the cache and validate what's found and that create on disk any missing metadata. (3) Normal running: states that allow netfs operations on objects to proceed and that update the state of objects. (4) Termination: states that detach objects from their netfs cookies, that delete objects from disk, that handle disk and system errors and that free up in-memory resources. In most cases, transitioning between states is in response to signalled events. When a state has finished processing, it will usually set the mask of events in which it is interested (object->event_mask) and relinquish the worker thread. Then when an event is raised (by calling fscache_raise_event()), if the event is not masked, the object will be queued for processing (by calling fscache_enqueue_object()). PROVISION OF CPU TIME --------------------- The work to be done by the various states is given CPU time by the threads of the slow work facility (see Documentation/slow-work.txt). This is used in preference to the workqueue facility because: (1) Threads may be completely occupied for very long periods of time by a particular work item. These state actions may be doing sequences of synchronous, journalled disk accesses (lookup, mkdir, create, setxattr, getxattr, truncate, unlink, rmdir, rename). (2) Threads may do little actual work, but may rather spend a lot of time sleeping on I/O. This means that single-threaded and 1-per-CPU-threaded workqueues don't necessarily have the right numbers of threads. LOCKING SIMPLIFICATION ---------------------- Because only one worker thread may be operating on any particular object's state machine at once, this simplifies the locking, particularly with respect to disconnecting the netfs's representation of a cache object (fscache_cookie) from the cache backend's representation (fscache_object) - which may be requested from either end. ================= THE SET OF STATES ================= The object state machine has a set of states that it can be in. There are preparation states in which the object sets itself up and waits for its parent object to transit to a state that allows access to its children: (1) State FSCACHE_OBJECT_INIT. Initialise the object and wait for the parent object to become active. In the cache, it is expected that it will not be possible to look an object up from the parent object, until that parent object itself has been looked up. There are initialisation states in which the object sets itself up and accesses disk for the object metadata: (2) State FSCACHE_OBJECT_LOOKING_UP. Look up the object on disk, using the parent as a starting point. FS-Cache expects the cache backend to probe the cache to see whether this object is represented there, and if it is, to see if it's valid (coherency management). The cache should call fscache_object_lookup_negative() to indicate lookup failure for whatever reason, and should call fscache_obtained_object() to indicate success. At the completion of lookup, FS-Cache will let the netfs go ahead with read operations, no matter whether the file is yet cached. If not yet cached, read operations will be immediately rejected with ENODATA until the first known page is uncached - as to that point there can be no data to be read out of the cache for that file that isn't currently also held in the pagecache. (3) State FSCACHE_OBJECT_CREATING. Create an object on disk, using the parent as a starting point. This happens if the lookup failed to find the object, or if the object's coherency data indicated what's on disk is out of date. In this state, FS-Cache expects the cache to create The cache should call fscache_obtained_object() if creation completes successfully, fscache_object_lookup_negative() otherwise. At the completion of creation, FS-Cache will start processing write operations the netfs has queued for an object. If creation failed, the write ops will be transparently discarded, and nothing recorded in the cache. There are some normal running states in which the object spends its time servicing netfs requests: (4) State FSCACHE_OBJECT_AVAILABLE. A transient state in which pending operations are started, child objects are permitted to advance from FSCACHE_OBJECT_INIT state, and temporary lookup data is freed. (5) State FSCACHE_OBJECT_ACTIVE. The normal running state. In this state, requests the netfs makes will be passed on to the cache. (6) State FSCACHE_OBJECT_UPDATING. The state machine comes here to update the object in the cache from the netfs's records. This involves updating the auxiliary data that is used to maintain coherency. And there are terminal states in which an object cleans itself up, deallocates memory and potentially deletes stuff from disk: (7) State FSCACHE_OBJECT_LC_DYING. The object comes here if it is dying because of a lookup or creation error. This would be due to a disk error or system error of some sort. Temporary data is cleaned up, and the parent is released. (8) State FSCACHE_OBJECT_DYING. The object comes here if it is dying due to an error, because its parent cookie has been relinquished by the netfs or because the cache is being withdrawn. Any child objects waiting on this one are given CPU time so that they too can destroy themselves. This object waits for all its children to go away before advancing to the next state. (9) State FSCACHE_OBJECT_ABORT_INIT. The object comes to this state if it was waiting on its parent in FSCACHE_OBJECT_INIT, but its parent died. The object will destroy itself so that the parent may proceed from the FSCACHE_OBJECT_DYING state. (10) State FSCACHE_OBJECT_RELEASING. (11) State FSCACHE_OBJECT_RECYCLING. The object comes to one of these two states when dying once it is rid of all its children, if it is dying because the netfs relinquished its cookie. In the first state, the cached data is expected to persist, and in the second it will be deleted. (12) State FSCACHE_OBJECT_WITHDRAWING. The object transits to this state if the cache decides it wants to withdraw the object from service, perhaps to make space, but also due to error or just because the whole cache is being withdrawn. (13) State FSCACHE_OBJECT_DEAD. The object transits to this state when the in-memory object record is ready to be deleted. The object processor shouldn't ever see an object in this state. THE SET OF EVENTS ----------------- There are a number of events that can be raised to an object state machine: (*) FSCACHE_OBJECT_EV_UPDATE The netfs requested that an object be updated. The state machine will ask the cache backend to update the object, and the cache backend will ask the netfs for details of the change through its cookie definition ops. (*) FSCACHE_OBJECT_EV_CLEARED This is signalled in two circumstances: (a) when an object's last child object is dropped and (b) when the last operation outstanding on an object is completed. This is used to proceed from the dying state. (*) FSCACHE_OBJECT_EV_ERROR This is signalled when an I/O error occurs during the processing of some object. (*) FSCACHE_OBJECT_EV_RELEASE (*) FSCACHE_OBJECT_EV_RETIRE These are signalled when the netfs relinquishes a cookie it was using. The event selected depends on whether the netfs asks for the backing object to be retired (deleted) or retained. (*) FSCACHE_OBJECT_EV_WITHDRAW This is signalled when the cache backend wants to withdraw an object. This means that the object will have to be detached from the netfs's cookie. Because the withdrawing releasing/retiring events are all handled by the object state machine, it doesn't matter if there's a collision with both ends trying to sever the connection at the same time. The state machine can just pick which one it wants to honour, and that effects the other. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>	16 years ago
David Howells	7394daa8c6	FS-Cache: Add use of /proc and presentation of statistics ... Make FS-Cache create its /proc interface and present various statistical information through it. Also provide the functions for updating this information. These features are enabled by: CONFIG_FSCACHE_PROC CONFIG_FSCACHE_STATS CONFIG_FSCACHE_HISTOGRAM The /proc directory for FS-Cache is also exported so that caching modules can add their own statistics there too. The FS-Cache module is loadable at this point, and the statistics files can be examined by userspace: cat /proc/fs/fscache/stats cat /proc/fs/fscache/histogram Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>	16 years ago
David Howells	0dfc41d1ef	FS-Cache: Add the FS-Cache cache backend API and documentation ... Add the API for a generic facility (FS-Cache) by which caches may declare them selves open for business, and may obtain work to be done from network filesystems. The header file is included by: #include <linux/fscache-cache.h> Documentation for the API is also added to: Documentation/filesystems/caching/backend-api.txt This API is not usable without the implementation of the utility functions which will be added in further patches. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>	16 years ago
David Howells	2d6fff6370	FS-Cache: Add the FS-Cache netfs API and documentation ... Add the API for a generic facility (FS-Cache) by which filesystems (such as AFS or NFS) may call on local caching capabilities without having to know anything about how the cache works, or even if there is a cache: +---------+ | | +--------------+ | NFS |--+ | | | | | +-->| CacheFS | +---------+ | +----------+ | | /dev/hda5 | | | | | +--------------+ +---------+ +-->| | | | | | |--+ | AFS |----->| FS-Cache | | | | |--+ +---------+ +-->| | | | | | | +--------------+ +---------+ | +----------+ | | | | | | +-->| CacheFiles | | ISOFS |--+ | /var/cache | | | +--------------+ +---------+ General documentation and documentation of the netfs specific API are provided in addition to the header files. As this patch stands, it is possible to build a filesystem against the facility and attempt to use it. All that will happen is that all requests will be immediately denied as if no cache is present. Further patches will implement the core of the facility. The facility will transfer requests from networking filesystems to appropriate caches if possible, or else gracefully deny them. If this facility is disabled in the kernel configuration, then all its operations will trivially reduce to nothing during compilation. WHY NOT I_MAPPING? ================== I have added my own API to implement caching rather than using i_mapping to do this for a number of reasons. These have been discussed a lot on the LKML and CacheFS mailing lists, but to summarise the basics: (1) Most filesystems don't do hole reportage. Holes in files are treated as blocks of zeros and can't be distinguished otherwise, making it difficult to distinguish blocks that have been read from the network and cached from those that haven't. (2) The backing inode must be fully populated before being exposed to userspace through the main inode because the VM/VFS goes directly to the backing inode and does not interrogate the front inode's VM ops. Therefore: (a) The backing inode must fit entirely within the cache. (b) All backed files currently open must fit entirely within the cache at the same time. (c) A working set of files in total larger than the cache may not be cached. (d) A file may not grow larger than the available space in the cache. (e) A file that's open and cached, and remotely grows larger than the cache is potentially stuffed. (3) Writes go to the backing filesystem, and can only be transferred to the network when the file is closed. (4) There's no record of what changes have been made, so the whole file must be written back. (5) The pages belong to the backing filesystem, and all metadata associated with that page are relevant only to the backing filesystem, and not anything stacked atop it. OVERVIEW ======== FS-Cache provides (or will provide) the following facilities: (1) Caches can be added / removed at any time, even whilst in use. (2) Adds a facility by which tags can be used to refer to caches, even if they're not available yet. (3) More than one cache can be used at once. Caches can be selected explicitly by use of tags. (4) The netfs is provided with an interface that allows either party to withdraw caching facilities from a file (required for (1)). (5) A netfs may annotate cache objects that belongs to it. This permits the storage of coherency maintenance data. (6) Cache objects will be pinnable and space reservations will be possible. (7) The interface to the netfs returns as few errors as possible, preferring rather to let the netfs remain oblivious. (8) Cookies are used to represent indices, files and other objects to the netfs. The simplest cookie is just a NULL pointer - indicating nothing cached there. (9) The netfs is allowed to propose - dynamically - any index hierarchy it desires, though it must be aware that the index search function is recursive, stack space is limited, and indices can only be children of indices. (10) Indices can be used to group files together to reduce key size and to make group invalidation easier. The use of indices may make lookup quicker, but that's cache dependent. (11) Data I/O is effectively done directly to and from the netfs's pages. The netfs indicates that page A is at index B of the data-file represented by cookie C, and that it should be read or written. The cache backend may or may not start I/O on that page, but if it does, a netfs callback will be invoked to indicate completion. The I/O may be either synchronous or asynchronous. (12) Cookies can be "retired" upon release. At this point FS-Cache will mark them as obsolete and the index hierarchy rooted at that point will get recycled. (13) The netfs provides a "match" function for index searches. In addition to saying whether a match was made or not, this can also specify that an entry should be updated or deleted. FS-Cache maintains a virtual index tree in which all indices, files, objects and pages are kept. Bits of this tree may actually reside in one or more caches. FSDEF | +------------------------------------+ | | NFS AFS | | +--------------------------+ +-----------+ | | | | homedir mirror afs.org redhat.com | | | +------------+ +---------------+ +----------+ | | | | | | 00001 00002 00007 00125 vol00001 vol00002 | | | | | +---+---+ +-----+ +---+ +------+------+ +-----+----+ | | | | | | | | | | | | | PG0 PG1 PG2 PG0 XATTR PG0 PG1 DIRENT DIRENT DIRENT R/W R/O Bak | | PG0 +-------+ | | 00001 00003 | +---+---+ | | | PG0 PG1 PG2 In the example above, two netfs's can be seen to be backed: NFS and AFS. These have different index hierarchies: (*) The NFS primary index will probably contain per-server indices. Each server index is indexed by NFS file handles to get data file objects. Each data file objects can have an array of pages, but may also have further child objects, such as extended attributes and directory entries. Extended attribute objects themselves have page-array contents. (*) The AFS primary index contains per-cell indices. Each cell index contains per-logical-volume indices. Each of volume index contains up to three indices for the read-write, read-only and backup mirrors of those volumes. Each of these contains vnode data file objects, each of which contains an array of pages. The very top index is the FS-Cache master index in which individual netfs's have entries. Any index object may reside in more than one cache, provided it only has index children. Any index with non-index object children will be assumed to only reside in one cache. The FS-Cache overview can be found in: Documentation/filesystems/caching/fscache.txt The netfs API to FS-Cache can be found in: Documentation/filesystems/caching/netfs-api.txt Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>	16 years ago
David Howells	8f0aa2f25b	Document the slow work thread pool ... Document the slow work thread pool. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Steve Dickson <steved@redhat.com> Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Daire Byrne <Daire.Byrne@framestore.com>	16 years ago
Leubner, Achim	d8e9650765	[SCSI] aacraid driver update ... changes: - set aac_cache=2 as default value to avoid performance problem (Novell bugzilla #469922) - Dell/PERC controller boot problem fixed (RedHat bugzilla #457552) - WWN flag added to fix SLES10 SP1/SP2 drive detection problems - 64-bit support changes - DECLARE_PCI_DEVICE_TABLE macro added - controller type changes Signed-off-by: Achim Leubner <aacraid@adaptec.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>	16 years ago
KAMEZAWA Hiroyuki	0b7f569e45	memcg: fix OOM killer under memcg ... This patch tries to fix OOM Killer problems caused by hierarchy. Now, memcg itself has OOM KILL function (in oom_kill.c) and tries to kill a task in memcg. But, when hierarchy is used, it's broken and correct task cannot be killed. For example, in following cgroup /groupA/ hierarchy=1, limit=1G, 01 nolimit 02 nolimit All tasks' memory usage under /groupA, /groupA/01, groupA/02 is limited to groupA's 1Gbytes but OOM Killer just kills tasks in groupA. This patch provides makes the bad process be selected from all tasks under hierarchy. BTW, currently, oom_jiffies is updated against groupA in above case. oom_jiffies of tree should be updated. To see how oom_jiffies is used, please check mem_cgroup_oom_called() callers. [akpm@linux-foundation.org: build fix] [akpm@linux-foundation.org: const fix] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Li Zefan	b6719ec1ad	cgroups: more documentation for remount and release_agent ... This won't remove cpuacct from the mounted hierachy: # mount -t cgroup -o cpu,cpuacct xxx /mnt # mount -o remount,cpu /mnt Because for this usage mount(8) will append the new options to the original options. And this will get you right: # mount [-t cgroup] -o remount,cpu xxx /mnt Also document how to specify or change release_agent. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Reviewd-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
KAMEZAWA Hiroyuki	ec64f51545	cgroup: fix frequent -EBUSY at rmdir ... In following situation, with memory subsystem, /groupA use_hierarchy==1 /01 some tasks /02 some tasks /03 some tasks /04 empty When tasks under 01/02/03 hit limit on /groupA, hierarchical reclaim is triggered and the kernel walks tree under groupA. In this case, rmdir /groupA/04 fails with -EBUSY frequently because of temporal refcnt from the kernel. In general. cgroup can be rmdir'd if there are no children groups and no tasks. Frequent fails of rmdir() is not useful to users. (And the reason for -EBUSY is unknown to users.....in most cases) This patch tries to modify above behavior, by - retries if css_refcnt is got by someone. - add "return value" to pre_destroy() and allows subsystem to say "we're really busy!" Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Li Xiaodong	45dad7bd9d	documentation: fix unix_dgram_qlen description ... Previous description about system parameter in /proc/sys/net/unix/ is wrong (or missed). Simply add a new description about unix_dgram_qlen according to latest kernel. Signed-off-by: Li Xiaodong <lixd@cn.fujitsu.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Shen Feng	760df93ecd	documentation: update Documentation/filesystem/proc.txt and Documentation/sysctls ... Now /proc/sys is described in many places and much information is redundant. This patch updates the proc.txt and move the /proc/sys desciption out to the files in Documentation/sysctls. Details are: merge - 2.1 /proc/sys/fs - File system data - 2.11 /proc/sys/fs/mqueue - POSIX message queues filesystem - 2.17 /proc/sys/fs/epoll - Configuration options for the epoll interface with Documentation/sysctls/fs.txt. remove - 2.2 /proc/sys/fs/binfmt_misc - Miscellaneous binary formats since it's not better then the Documentation/binfmt_misc.txt. merge - 2.3 /proc/sys/kernel - general kernel parameters with Documentation/sysctls/kernel.txt remove - 2.5 /proc/sys/dev - Device specific parameters since it's obsolete the sysfs is used now. remove - 2.6 /proc/sys/sunrpc - Remote procedure calls since it's not better then the Documentation/sysctls/sunrpc.txt move - 2.7 /proc/sys/net - Networking stuff - 2.9 Appletalk - 2.10 IPX to newly created Documentation/sysctls/net.txt. remove - 2.8 /proc/sys/net/ipv4 - IPV4 settings since it's not better then the Documentation/networking/ip-sysctl.txt. add - Chapter 3 Per-Process Parameters to descibe /proc/<pid>/xxx parameters. Signed-off-by: Shen Feng <shen@cn.fujitsu.com> Cc: Randy Dunlap <randy.dunlap@oracle.com> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Henrik Austad	70eed8d066	documentation: ignore byproducts from latex ... When using 'make pdfdocs', auto-generated files should be ignored Signed-off-by: Henrik Austad <henrik@austad.us> Cc: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
David Brownell	8a0cecffeb	gpio: gpio_{request,free}() now required (feature removal) ... We want to phase out the GPIO "autorequest" mechanism in gpiolib and require all callers to use gpio_request(). - Update feature-removal-schedule - Update the documentation now - Convert the relevant pr_warning() in gpiolib to a WARN() so folk using this mechanism get a noisy stack dump Some drivers and board init code will probably need to change. Implementations not using gpiolib will still be fine; they are already required to implement gpio_{request,free}() stubs. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Luca Tettamanti	7e90560c50	ACPI: acpi_enforce_resource=strict by default ... Enforce strict resource checking - disallowing access by native drivers to IO ports and memory regions claimed by ACPI firmware. The patch is mainly aimed to block native hwmon drivers from touching monitoring chips that ACPI thinks it own. If this causes a regression, boot with "acpi_enforce_resources=lax" which was the previous default. http://bugzilla.kernel.org/show_bug.cgi?id=12376 http://bugzilla.kernel.org/show_bug.cgi?id=12541 Signed-off-by: Luca Tettamanti <kronos.it@gmail.com> Acked-by: Pavel Machek <pavel@suse.cz> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Len Brown <len.brown@intel.com>	16 years ago
Mark Brown	a7808331f1	ASoC: Add some documentation for the ASoC jack API ... A brief overview of how the components of the API fit together. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>	16 years ago
Marcin Slusarz	7ac9bcd5da	udf: implement mode and dmode mounting options ... "dmode" allows overriding permissions of directories and "mode" allows overriding permissions of files. Signed-off-by: Marcin Slusarz <marcin.slusarz@gmail.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Jan Kara <jack@suse.cz>	16 years ago
Jesper Dangaard Brouer	edd4070f5d	Doc: Fix spelling in RCU/rculist_nulls.txt. ... Doc: Fix spelling in RCU/rculist_nulls.txt. Trival spelling fixes in RCU/rculist_nulls.txt. Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk> Tested-by: Jarek Poplawski <jarkao2@gmail.com;-> Signed-off-by: David S. Miller <davem@davemloft.net>	16 years ago
Jesper Dangaard Brouer	3943ac5d99	Doc: Fix wrong API example usage of call_rcu(). ... At some point the API of call_rcu() changed from three parameters to two parameters, correct the documentation. One confusing thing in RCU/listRCU.txt, which is NOT fixed in this patch, is that no reason or explaination is given for using call_rcu() instead of the normal synchronize_rcu() call. Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk> Signed-off-by: David S. Miller <davem@davemloft.net>	16 years ago
Jesper Dangaard Brouer	9ba30d7444	Doc: Fix missing whitespaces in RCU documentation. ... Trivial fix while reading through the RCU docs. Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk> Signed-off-by: David S. Miller <davem@davemloft.net>	16 years ago
Ramkrishna Vepa	5adfb64bdd	Neterion: Driver help file ... - vxge driver help text file. - No change from previous submission. - Changes in previous submissions - Removed the performance tuning section with instructions to disable time stamps and change sysctl settings - Reported by Dave Miller General clean up. - Removed tx/rx_pause, exec_mode, tx_steering_type, rx_steering_type, gro, intr_type, rx & tx max_indicate_pkts and exec_mode loadable parameters. The driver default settings work well in most if not all cases. Another patch to configure these parameters with ethtool will be released in the future - Reported by Stephen Hemminger. - Incorporated following fixes based on comments from Ben Hutchings Removed references to earlier kernel versions. Removed sections that are similar for all drivers - Load/Unload Identifying the adapter/interface Boot time configuration Removed loadable parameter - NAPI - Napi is always enabled. rx_steering_type & ring_blocks - The driver default settings work well in most if not all cases. Another patch to configure these parameters with ethtool will be released in the future. Removed ethtool support section - No need to duplicate ethtool docs here. Removed Known Issue on SUSE 9 - Doesn't apply when using a current kernel. Removed Common Problems section - These don't apply to in-tree modules. Removed Available Downloads section - Not sure this belongs in-tree. Removed Copyright information - This notice doesn't belong in the kernel. Signed-off-by: Sivakumar Subramani <sivakumar.subramani@neterion.com> Signed-off-by: Rastapur Santosh <santosh.rastapur@neterion.com> Signed-off-by: Ramkrishna Vepa <ram.vepa@neterion.com> Signed-off-by: David S. Miller <davem@davemloft.net>	16 years ago
Paul Mundt	eeee7853c4	sh: Add a command line option for disabling I/O trapping. ... This adds a 'noiotrap' kernel command line option to permit disabling of I/O trapping. This is mostly useful for running on emulators where the physical device limitations are not an issue. Signed-off-by: Paul Mundt <lethal@linux-sh.org>	16 years ago
Paulius Zaleckas	01a24d2b93	[ARM] 5437/1: Add documentation for "nohlt" kernel parameter ... As per discussion in: http://marc.info/?l=linux-arm-kernel&m=123633652517391&w=2 Signed-off-by: Paulius Zaleckas <paulius.zaleckas@teltonika.lt> Acked-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>	16 years ago
Krzysztof Helt	ddb53d48da	fbdev: remove cyblafb driver ... A tridentfb driver has all the functionality of the cyblafb driver without the bugs of the latter. Changes to the tridentfb driver: - FBINFO_READS_FAST added to the tridentfb. The cyblafb used a blitter for scrolling which is faster than color expansion on Cyberblade chipsets. The blitter is slower on a discrete Blade3D core. Use the blitter for scrolling in the tridentfb only for integrated Blade3D cores. Now, scrolling speed is about equal for the tridentfb and the cyblafb. - a copyright notice addition is done on request of Jani Monoses (the first author of the tridentfb). Tested on AGP Blade3D card and PCChips M787CLR motherboard: VIA C3 cpu + VT8601 north bridge (aka Cyberblade/i1). Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl> Cc: "Jani Monoses" <jani@ubuntu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Anton Vorontsov	3f1c6ebf57	powerpc: add mmc-spi-slot bindings ... The bindings describes a case where MMC/SD/SDIO slot directly connected to a SPI bus. Such setups are widely used on embedded PowerPC boards. The patch also adds the mmc-spi-slot entry to the OpenFirmware modalias table. Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com> Cc: David Brownell <david-b@pacbell.net> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Kumar Gala <galak@gate.crashing.org> Cc: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Ira Snyder	72f5de92e1	hwmon: Add LTC4215 driver ... Add Linux support for the Linear Technology LTC4215 Hot Swap controller I2C monitoring interface. I have tested the driver with my board, and it appears to work fine. With the power supplies disabled, it reads 11.93V input, 1.93V output, no current and no power. With the supplies enabled, it reads 11.93V input, 11.98V output, no current, no power. I'm not drawing any current at the moment, so this is reasonable. The value in the sense register never reads anything except 0, so I expect to get zero from the current and power calculations. I didn't attempt to support changing any of the chip's settings or enabling the FET. I'm not sure even how to do that and still fit within the hwmon framework. :) Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu> Cc: Jean Delvare <khali@linux-fr.org> Cc: "Mark M. Hoffman" <mhoffman@lightlink.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Pavel Machek	2b872903c5	hp_accel: small documentation updates ... Fix english in Documentation, add "how to test" description. Signed-off-by: Pavel Machek <pavel@suse.cz> Cc: Eric Piel <eric.piel@tremplin-utc.net> Cc: Vladimir Botka <vbotka@suse.cz> Cc: <Quoc.Pham@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Daniel Mack	3cdbbeebb7	drivers/misc/isl29003.c: driver for the ISL29003 ambient light sensor ... Add a driver for Intersil's ISL29003 ambient light sensor device plus some documentation. Inspired by tsl2550.c, a driver for a similar device. It is put in drivers/misc for now until the industrial I/O framework gets merged. Signed-off-by: Daniel Mack <daniel@caiaq.de> Acked-by: Jonathan Cameron <jic23@cam.ac.uk> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Eric Sandeen	c2d7543851	filesystem freeze: allow SysRq emergency thaw to thaw frozen filesystems ... Now that the filesystem freeze operation has been elevated to the VFS, and is just an ioctl away, some sort of safety net for unintentionally frozen root filesystems may be in order. The timeout thaw originally proposed did not get merged, but perhaps something like this would be useful in emergencies. For example, freeze /path/to/mountpoint may freeze your root filesystem if you forgot that you had that unmounted. I chose 'j' as the last remaining character other than 'h' which is sort of reserved for help (because help is generated on any unknown character). I've tested this on a non-root fs with multiple (nested) freezers, as well as on a system rendered unresponsive due to a frozen root fs. [randy.dunlap@oracle.com: emergency thaw only if CONFIG_BLOCK enabled] Signed-off-by: Eric Sandeen <sandeen@redhat.com> Cc: Takashi Sato <t-sato@yk.jp.nec.com> Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Nick Piggin	c2ec175c39	mm: page_mkwrite change prototype to match fault ... Change the page_mkwrite prototype to take a struct vm_fault, and return VM_FAULT_xxx flags. There should be no functional change. This makes it possible to return much more detailed error information to the VM (and also can provide more information eg. virtual_address to the driver, which might be important in some special cases). This is required for a subsequent fix. And will also make it easier to merge page_mkwrite() with fault() in future. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Chris Mason <chris.mason@oracle.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Artem Bityutskiy <dedekind@infradead.org> Cc: Felix Blyakher <felixb@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Ravikiran G Thirumalai	2584e51732	mm: reintroduce and deprecate rlimit based access for SHM_HUGETLB ... Allow non root users with sufficient mlock rlimits to be able to allocate hugetlb backed shm for now. Deprecate this though. This is being deprecated because the mlock based rlimit checks for SHM_HUGETLB is not consistent with mmap based huge page allocations. Signed-off-by: Ravikiran Thirumalai <kiran@scalex86.org> Reviewed-by: Mel Gorman <mel@csn.ul.ie> Cc: William Lee Irwin III <wli@holomorphy.com> Cc: Adam Litke <agl@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>	16 years ago
Bharata B Rao	ef12fefabf	cpuacct: add per-cgroup utime/stime statistics ... Add per-cgroup cpuacct controller statistics like the system and user time consumed by the group of tasks. Changelog: v7 - Changed the name of the statistic from utime to user and from stime to system so that in future we could easily add other statistics like irq, softirq, steal times etc easily. v6 - Fixed a bug in the error path of cpuacct_create() (pointed by Li Zefan). v5 - In cpuacct_stats_show(), use cputime64_to_clock_t() since we are operating on a 64bit variable here. v4 - Remove comments in cpuacct_update_stats() which explained why rcu_read_lock() was needed (as per Peter Zijlstra's review comments). - Don't say that percpu_counter_read() is broken in Documentation/cpuacct.txt as per KAMEZAWA Hiroyuki's review comments. v3 - Fix a small race in the cpuacct hierarchy walk. v2 - stime and utime now exported in clock_t units instead of msecs. - Addressed the code review comments from Balbir and Li Zefan. - Moved to -tip tree. v1 - Moved the stime/utime accounting to cpuacct controller. Earlier versions - http://lkml.org/lkml/2009/2/25/129 Signed-off-by: Bharata B Rao <bharata@linux.vnet.ibm.com> Signed-off-by: Balaji Rao <balajirrao@gmail.com> Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com> Cc: Paul Menage <menage@google.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Tested-by: Balbir Singh <balbir@linux.vnet.ibm.com> LKML-Reference: <20090331043222.GA4093@in.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>	16 years ago
Boaz Harrosh	214c8adb87	exofs: Documentation ... Added some documentation in exofs.txt, as well as a BUGS file. For further reading, operation instructions, example scripts and up to date infomation and code please see: http://open-osd.org Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>	16 years ago
David Brownell	853116a105	regulator: add get_status() ... Based on previous LKML discussions: * Update docs for regulator sysfs class attributes to highlight the fact that all current attributes are intended to be control inputs, including notably "state" and "opmode" which previously implied otherwise. * Define a new regulator driver get_status() method, which is the first method reporting regulator outputs instead of inputs. It can report on/off and error status; or instead of simply "on", report the actual operating mode. For the moment, this is a sysfs-only interface, not accessible to regulator clients. Such clients can use the current notification interfaces to detect errors, if the regulator reports them. Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>	16 years ago
NeilBrown	1137354234	Documentation/md.txt update ... Update md.txt to reflect recent changes in a number of sysfs attributes. Signed-off-by: NeilBrown <neilb@suse.de>	16 years ago
Alexey Dobriyan	99b7623380	proc 2/2: remove struct proc_dir_entry::owner ... Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy as correctly noted at bug #12454. Someone can lookup entry with NULL ->owner, thus not pinning enything, and release it later resulting in module refcount underflow. We can keep ->owner and supply it at registration time like ->proc_fops and ->data. But this leaves ->owner as easy-manipulative field (just one C assignment) and somebody will forget to unpin previous/pin current module when switching ->owner. ->proc_fops is declared as "const" which should give some thoughts. ->read_proc/->write_proc were just fixed to not require ->owner for protection. rmmod'ed directories will be empty and return "." and ".." -- no harm. And directories with tricky enough readdir and lookup shouldn't be modular. We definitely don't want such modular code. Removing ->owner will also make PDE smaller. So, let's nuke it. Kudos to Jeff Layton for reminding about this, let's say, oversight. http://bugzilla.kernel.org/show_bug.cgi?id=12454 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>	16 years ago
Jean Delvare	ec19920944	hwmon: Define a standard interface for chassis intrusion detection ... Define a standard interface for the chassis intrusion detection feature some hardware monitoring chips have. Some drivers have custom sysfs entries for it, but a standard interface would allow integration with user-space (namely libsensors.) Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Hans de Goede <j.w.r.degoede@hhs.nl> Acked-by: Matt Roberds <mattroberds@cox.net>	16 years ago
Jean Delvare	fb4504fe84	Move the pcf8591 driver to hwmon ... Directory drivers/i2c/chips is going away, so drivers there must find new homes. For the pcf8591 driver, the best choice seems to be the hwmon subsystem. While the Philips PCF8591 device isn't a typical hardware monitoring chip, its DAC interface is compatible with the hwmon one, so it fits somewhat. If a better subsystem is ever created for ADC/DAC chips, the driver could be moved there. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Aurelien Jarno <aurelien@aurel32.net>	16 years ago
Gong Jun	237c8d2f54	hwmon: (w83627ehf) Add support for W83667HG ... Add initial support for the Nuvoton W83667HG chip to the w83627ehf driver. It has been tested on ASUS P5QL PRO by Gong Jun. At the moment there is still a usability issue which is that only in6 or temp3 can be present on the W83667HG, so the driver shouldn't expose both. This will be addressed later. Signed-off-by: Gong Jun <JGong@nuvoton.com> Acked-by: David Hubbard <david.c.hubbard@gmail.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>	16 years ago
Jean Delvare	25f3311acc	hwmon: (ds1621) Clean up documentation ... * The alarms sysfs file is deprecated, and individual alarm files are self-explanatory. * The driver doesn't implement high-reslution temperature readings so don't document that. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Aurelien Jarno <aurelien@aurel32.net>	16 years ago
Mauro Carvalho Chehab	aeecea2623	V4L/DVB (11225): v4lgrab: fix compilation warnings ... Documentation/video4linux/v4lgrab.c: In function ‘main’: Documentation/video4linux/v4lgrab.c:193: warning: ‘src_depth’ is used uninitialized in this function Documentation/video4linux/v4lgrab.c:108: warning: ‘b’ may be used uninitialized in this function Documentation/video4linux/v4lgrab.c:108: warning: ‘g’ may be used uninitialized in this function Documentation/video4linux/v4lgrab.c:108: warning: ‘r’ may be used uninitialized in this function Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>	16 years ago