aboutsummaryrefslogtreecommitdiff
path: root/include/linux/sysfs.h
AgeCommit message (Collapse)Author
2014-01-13Revert "kernfs, sysfs, driver-core: implement kernfs_remove_self() and its ↵Greg Kroah-Hartman
wrappers" This reverts commit 1ae06819c77cff1ea2833c94f8c093fe8a5c79db. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-13Revert "sysfs, driver-core: remove unused ↵Greg Kroah-Hartman
{sysfs|device}_schedule_callback_owner()" This reverts commit d1ba277e79889085a2faec3b68b91ce89c63f888. Tejun writes: I'm sorry but can you please revert the whole series? get_active() waiting while a node is deactivated has potential to lead to deadlock and that deactivate/reactivate interface is something fundamentally flawed and that cgroup will have to work with the remove_self() like everybody else. IOW, I think the first posting was correct. Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()Tejun Heo
All device_schedule_callback_owner() users are converted to use device_remove_file_self(). Remove now unused {sysfs|device}_schedule_callback_owner(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-01-10kernfs, sysfs, driver-core: implement kernfs_remove_self() and its wrappersTejun Heo
Sometimes it's necessary to implement a node which wants to delete nodes including itself. This isn't straightforward because of kernfs active reference. While a file operation is in progress, an active reference is held and kernfs_remove() waits for all such references to drain before completing. For a self-deleting node, this is a deadlock as kernfs_remove() ends up waiting for an active reference that itself is sitting on top of. This currently is worked around in the sysfs layer using sysfs_schedule_callback() which makes such removals asynchronous. While it works, it's rather cumbersome and inherently breaks synchronicity of the operation - the file operation which triggered the operation may complete before the removal is finished (or even started) and the removal may fail asynchronously. If a removal operation is immmediately followed by another operation which expects the specific name to be available (e.g. removal followed by rename onto the same name), there's no way to make the latter operation reliable. The thing is there's no inherent reason for this to be asynchrnous. All that's necessary to do this synchronous is a dedicated operation which drops its own active ref and deactivates self. This patch implements kernfs_remove_self() and its wrappers in sysfs and driver core. kernfs_remove_self() is to be called from one of the file operations, drops the active ref and deactivates using __kernfs_deactivate_self(), removes the self node, and restores active ref to the dead node using __kernfs_reactivate_self() so that the ref is balanced afterwards. __kernfs_remove() is updated so that it takes an early exit if the target node is already fully removed so that the active ref restored by kernfs_remove_self() after removal doesn't confuse the deactivation path. This makes implementing self-deleting nodes very easy. The normal removal path doesn't even need to be changed to use kernfs_remove_self() for the self-deleting node. The method can invoke kernfs_remove_self() on itself before proceeding the normal removal path. kernfs_remove() invoked on the node by the normal deletion path will simply be ignored. This will replace sysfs_schedule_callback(). A subtle feature of sysfs_schedule_callback() is that it collapses multiple invocations - even if multiple removals are triggered, the removal callback is run only once. An equivalent effect can be achieved by testing the return value of kernfs_remove_self() - only the one which gets %true return value should proceed with actual deletion. All other instances of kernfs_remove_self() will wait till the enclosing kernfs operation which invoked the winning instance of kernfs_remove_self() finishes and then return %false. This trivially makes all users of kernfs_remove_self() automatically show correct synchronous behavior even when there are multiple concurrent operations - all "echo 1 > delete" instances will finish only after the whole operation is completed by one of the instances. v2: For !CONFIG_SYSFS, dummy version kernfs_remove_self() was missing and sysfs_remove_file_self() had incorrect return type. Fix it. Reported by kbuild test bot. v3: Updated to use __kernfs_{de|re}activate_self(). Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-12-11kernfs: s/sysfs_dirent/kernfs_node/ and rename its friends accordinglyTejun Heo
kernfs has just been separated out from sysfs and we're already in full conflict mode. Nothing can make the situation any worse. Let's take the chance to name things properly. This patch performs the following renames. * s/sysfs_elem_dir/kernfs_elem_dir/ * s/sysfs_elem_symlink/kernfs_elem_symlink/ * s/sysfs_elem_attr/kernfs_elem_file/ * s/sysfs_dirent/kernfs_node/ * s/sd/kn/ in kernfs proper * s/parent_sd/parent/ * s/target_sd/target/ * s/dir_sd/parent/ * s/to_sysfs_dirent()/rb_to_kn()/ * misc renames of local vars when they conflict with the above Because md, mic and gpio dig into sysfs details, this patch ends up modifying them. All are sysfs_dirent renames and trivial. While we can avoid these by introducing a dummy wrapping struct sysfs_dirent around kernfs_node, given the limited usage outside kernfs and sysfs proper, I don't think such workaround is called for. This patch is strictly rename only and doesn't introduce any functional difference. - mic / gpio renames were missing. Spotted by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Neil Brown <neilb@suse.de> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Ashutosh Dixit <ashutosh.dixit@intel.com> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: introduce kernfs[_find_and]_get() and kernfs_put()Tejun Heo
Introduce kernfs interface for finding, getting and putting sysfs_dirents. * sysfs_find_dirent() is renamed to kernfs_find_ns() and lockdep assertion for sysfs_mutex is added. * sysfs_get_dirent_ns() is renamed to kernfs_find_and_get(). * Macro inline dancing around __sysfs_get/put() are removed and kernfs_get/put() are made proper functions implemented in fs/sysfs/dir.c. While the conversions are mostly equivalent, there's one difference - kernfs_get() doesn't return the input param as its return value. This change is intentional. While passing through the input increases writability in some areas, it is unnecessary and has been shown to cause confusion regarding how the last ref is handled. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: introduce kernfs_notify()Tejun Heo
Introduce kernfs interface to wake up poll(2) which takes and returns sysfs_dirents. sysfs_notify_dirent() is renamed to kernfs_notify() and sysfs_notify() is updated so that it doesn't directly grab sysfs_mutex but acquires the target sysfs_dirents using sysfs_get_dirent(). sysfs_notify_dirent() is reimplemented as a dumb inline wrapper around kernfs_notify(). This patch doesn't introduce any behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-29sysfs, kernfs: introduce kernfs_create_dir[_ns]()Tejun Heo
Introduce kernfs interface to manipulate a directory which takes and returns sysfs_dirents. create_dir() is renamed to kernfs_create_dir_ns() and its argumantes and return value are updated. create_dir() usages are replaced with kernfs_create_dir_ns() and sysfs_create_subdir() usages are replaced with kernfs_create_dir(). Dup warnings are handled explicitly by sysfs users of the kernfs interface. sysfs_enable_ns() is renamed to kernfs_enable_ns(). This patch doesn't introduce any behavior changes. v2: Dummy implementation for !CONFIG_SYSFS updated to return -ENOSYS. v3: kernfs_enable_ns() added. v4: Refreshed on top of "sysfs: drop kobj_ns_type handling, take #2" so that this patch removes sysfs_enable_ns(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-27sysfs, kernfs: add skeletons for kernfsTejun Heo
Core sysfs implementation will be separated into kernfs so that it can be used by other non-kobject users. This patch creates fs/kernfs/ directory and makes boilerplate changes. kernfs interface will be directly based on sysfs_dirent and its forward declaration is moved to include/linux/kernfs.h which is included from include/linux/sysfs.h. sysfs core implementation will be gradually separated out and moved to kernfs. This patch doesn't introduce any functional changes. v2: mount.c added. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: linux-fsdevel@vger.kernel.org Cc: Christoph Hellwig <hch@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-11-27sysfs: drop kobj_ns_type handling, take #2Tejun Heo
The way namespace tags are implemented in sysfs is more complicated than necessary. As each tag is a pointer value and required to be non-NULL under a namespace enabled parent, there's no need to record separately what type each tag is. If multiple namespace types are needed, which currently aren't, we can simply compare the tag to a set of allowed tags in the superblock assuming that the tags, being pointers, won't have the same value across multiple types. This patch rips out kobj_ns_type handling from sysfs. sysfs now has an enable switch to turn on namespace under a node. If enabled, all children are required to have non-NULL namespace tags and filtered against the super_block's tag. kobject namespace determination is now performed in lib/kobject.c::create_dir() making sysfs_read_ns_type() unnecessary. The sanity checks are also moved. create_dir() is restructured to ease such addition. This removes most kobject namespace knowledge from sysfs proper which will enable proper separation and layering of sysfs. This is the second try. The first one was cb26a311578e ("sysfs: drop kobj_ns_type handling") which tried to automatically enable namespace if there are children with non-NULL namespace tags; however, it was broken for symlinks as they should inherit the target's tag iff namespace is enabled in the parent. This led to namespace filtering enabled incorrectly for wireless net class devices through phy80211 symlinks and thus network configuration failure. a1212d278c05 ("Revert "sysfs: drop kobj_ns_type handling"") reverted the commit. This shouldn't introduce any behavior changes, for real. v2: Dummy implementation of sysfs_enable_ns() for !CONFIG_SYSFS was missing and caused build failure. Reported by kbuild test robot. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26sysfs: clean up sysfs_get_dirent()Tejun Heo
The pre-existing sysfs interfaces which take explicit namespace argument are weird in that they place the optional @ns in front of @name which is contrary to the established convention. For example, we end up forcing vast majority of sysfs_get_dirent() users to do sysfs_get_dirent(parent, NULL, name), which is silly and error-prone especially as @ns and @name may be interchanged without causing compilation warning. This renames sysfs_get_dirent() to sysfs_get_dirent_ns() and swap the positions of @name and @ns, and sysfs_get_dirent() is now a wrapper around sysfs_get_dirent_ns(). This makes confusions a lot less likely. There are other interfaces which take @ns before @name. They'll be updated by following patches. This patch doesn't introduce any functional changes. v2: EXPORT_SYMBOL_GPL() wasn't updated leading to undefined symbol error on module builds. Reported by build test robot. Fixed. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26sysfs: remove ktype->namespace() invocations in symlink codeTejun Heo
There's no reason for sysfs to be calling ktype->namespace(). It is backwards, obfuscates what's going on and unnecessarily tangles two separate layers. There are two places where symlink code calls ktype->namespace(). * sysfs_do_create_link_sd() calls it to find out the namespace tag of the target directory. Unless symlinking races with cross-namespace renaming, this equals @target_sd->s_ns. * sysfs_rename_link() uses it to find out the new namespace to rename to and the new namespace can be different from the existing one. The function is renamed to sysfs_rename_link_ns() with an explicit @ns argument and the ktype->namespace() invocation is shifted to the device layer. While this patch replaces ktype->namespace() invocation with the recorded result in @target_sd, this shouldn't result in any behvior difference. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26sysfs: remove ktype->namespace() invocations in directory codeTejun Heo
For some unrecognizable reason, namespace information is communicated to sysfs through ktype->namespace() callback when there's *nothing* which needs the use of a callback. The whole sequence of operations is completely synchronous and sysfs operations simply end up calling back into the layer which just invoked it in order to find out the namespace information, which is completely backwards, obfuscates what's going on and unnecessarily tangles two separate layers. This patch doesn't remove ktype->namespace() but shifts its handling to kobject layer. We probably want to get rid of the callback in the long term. This patch adds an explicit param to sysfs_{create|rename|move}_dir() and renames them to sysfs_{create|rename|move}_dir_ns(), respectively. ktype->namespace() invocations are moved to the calling sites of the above functions. A new helper kboject_namespace() is introduced which directly tests kobj_ns_type_operations->type which should give the same result as testing sysfs_fs_type(parent_sd) and returns @kobj's namespace tag as necessary. kobject_namespace() is extern as it will be used from another file in the following patches. This patch should be an equivalent conversion without any functional difference. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-26sysfs: make attr namespace interface less convolutedTejun Heo
sysfs ns (namespace) implementation became more convoluted than necessary while trying to hide ns information from visible interface. The relatively recent attr ns support is a good example. * attr ns tag is determined by sysfs_ops->namespace() callback while dir tag is determined by kobj_type->namespace(). The placement is arbitrary. * Instead of performing operations with explicit ns tag, the namespace callback is routed through sysfs_attr_ns(), sysfs_ops->namespace(), class_attr_namespace(), class_attr->namespace(). It's not simpler in any sense. The only thing this convolution does is traversing the whole stack backwards. The namespace callbacks are unncessary because the operations involved are inherently synchronous. The information can be provided in in straight-forward top-down direction and reversing that direction is unnecessary and against basic design principles. This backward interface is unnecessarily convoluted and hinders properly separating out sysfs from driver model / kobject for proper layering. This patch updates attr ns support such that * sysfs_ops->namespace() and class_attr->namespace() are dropped. * sysfs_{create|remove}_file_ns(), which take explicit @ns param, are added and sysfs_{create|remove}_file() are now simple wrappers around the ns aware functions. * ns handling is dropped from sysfs_chmod_file(). Nobody uses it at this point. sysfs_chmod_file_ns() can be added later if necessary. * Explicit @ns is propagated through class_{create|remove}_file_ns() and netdev_class_{create|remove}_file_ns(). * driver/net/bonding which is currently the only user of attr namespace is updated to use netdev_class_{create|remove}_file_ns() with @bh->net as the ns tag instead of using the namespace callback. This patch should be an equivalent conversion without any functional difference. It makes the code easier to follow, reduces lines of code a bit and helps proper separation and layering. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Kay Sievers <kay@vrfy.org> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-28sysfs: sysfs_create_groups returns a value.Greg Kroah-Hartman
When I included the "empty" function for sysfs_create_groups() when CONFIG_SYSFS=n, I forgot to return a value for it, so things blew up the build. This patch fixes that, stupid me. Reported-by: kbuild test robot <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-27sysfs: add sysfs_create/remove_groups for when SYSFS is not enabledGreg Kroah-Hartman
We need these functions for when CONFIG_SYSFS=n. Reported-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-23sysfs: create __ATTR_WO()Greg Kroah-Hartman
This creates the macro __ATTR_WO() for write-only attributes, instead of having to "open define" them. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-22sysfs.h: remove attr_name() macroGreg Kroah-Hartman
Gotta love a macro that doesn't reduce the typing you have to do. Also, only the driver core, and one network driver uses this. The driver core functions will be going away soon, and I'll convert the network driver soon to not need this as well, so delete it for now before anyone else gets some bright ideas and wants to use it. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-21sysfs: fix up minor coding style issues in sysfs.hGreg Kroah-Hartman
As long as we are cleaning up sysfs coding style issues, don't forget the main sysfs.h file, so fix up the space issues there as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-21sysfs: add sysfs_create/remove_groups()Greg Kroah-Hartman
These functions are being open-coded in 3 different places in the driver core, and other driver subsystems will want to start doing this as well, so move it to the sysfs core to keep it all in one place, where we know it is written properly. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-20sysfs.h: fix __BIN_ATTR_RW()Greg Kroah-Hartman
__BIN_ATTR_RW() wasn't passing in the _size field. As it would break the build if this macro was ever used, it's obvious no one had ever tried to use it before. Fix it so that it can be used. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-16sysfs: use file mode defines from stat.hOliver Schinagl
With the last patches stat.h was included to the header, and thus those permission defines should be used. Signed-off-by: Oliver Schinagl <oliver@schinagl.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-16sysfs: add more helper macro's for (bin_)attribute(_groups)Oliver Schinagl
With the recent changes to sysfs there's various helper macro's. However there's no RW, RO BIN_ helper macro's. This patch adds them. Signed-off-by: Oliver Schinagl <oliver@schinagl.nl> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-16sysfs: add support for binary attributes in groupsGreg Kroah-Hartman
groups should be able to support binary attributes, just like it supports "normal" attributes. This lets us only handle one type of structure, groups, throughout the driver core and subsystems, making binary attributes a "full fledged" part of the driver model, and not something just "tacked on". Reported-by: Oliver Schinagl <oliver@schinagl.nl> Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-16sysfs.h: add BIN_ATTR macroGreg Kroah-Hartman
This makes it easier to create static binary attributes, which is needed in a number of drivers, instead of "open coding" them. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-16sysfs.h: add ATTRIBUTE_GROUPS() macroGreg Kroah-Hartman
To make it easier for driver subsystems to work with attribute groups, create the ATTRIBUTE_GROUPS macro to remove some of the repetitive typing for the most common use for attribute groups. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-16sysfs.h: add __ATTR_RW() macroGreg Kroah-Hartman
A number of parts of the kernel created their own version of this, might as well have the sysfs core provide it instead. Reviewed-by: Guenter Roeck <linux@roeck-us.net> Tested-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-01-25sysfs: Functions for adding/removing symlinks to/from attribute groupsRafael J. Wysocki
The most convenient way to expose ACPI power resources lists of a device is to put symbolic links to sysfs directories representing those resources into special attribute groups in the device's sysfs directory. For this purpose, it is necessary to be able to add symbolic links to attribute groups. For this reason, add sysfs helper functions for adding/removing symbolic links to/from attribute groups, sysfs_add_link_to_group() and sysfs_remove_link_from_group(), respectively. This change set includes a build fix from David Rientjes. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-05-14sysfs: get rid of some lockdep false positivesAlan Stern
This patch (as1554) fixes a lockdep false-positive report. The problem arises because lockdep is unable to deal with the tree-structured locks created by the device core and sysfs. This particular problem involves a sysfs attribute method that unregisters itself, not from the device it was called for, but from a descendant device. Lockdep doesn't understand the distinction and reports a possible deadlock, even though the operation is safe. This is the sort of thing that would normally be handled by using a nested lock annotation; unfortunately it's not feasible to do that here. There's no sensible way to tell sysfs when attribute removal occurs in the context of a parent attribute method. As a workaround, the patch adds a new flag to struct attribute telling sysfs not to inform lockdep when it acquires a readlock on a sysfs_dirent instance for the attribute. The readlock is still acquired, but lockdep doesn't know about it and hence does not complain about impossible deadlock scenarios. Also added are macros for static initialization of attribute structures with the ignore_lockdep flag set. The three offending attributes in the USB subsystem are converted to use the new macros. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Tejun Heo <tj@kernel.org> CC: Eric W. Biederman <ebiederm@xmission.com> CC: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-01-03switch sysfs_chmod_file() to umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03switch ->is_visible() to returning umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03switch sysfs attr->mode to umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-10-19sysfs: Implement support for tagged files in sysfs.Eric W. Biederman
Looking up files in sysfs is hard to understand and analyize because we currently allow placing untagged files in tagged directories. In the implementation of that we have two subtly different meanings of NULL. NULL meaning there is no tag on a directory entry and NULL meaning we don't care which namespace the lookup is performed for. This multiple uses of NULL have resulted in subtle bugs (since fixed) in the code. Currently it is only the bonding driver that needs to have an untagged file in a tagged directory. To untagle this mess I am adding support for tagged files to sysfs. Modifying the bonding driver to implement bonding_masters as a tagged file. Registering bonding_masters once for each network namespace. Then I am removing support for untagged entries in tagged sysfs directories. Resulting in code that is much easier to reason about. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-12Delay struct net freeing while there's a sysfs instance refering to itAl Viro
* new refcount in struct net, controlling actual freeing of the memory * new method in kobj_ns_type_operations (->drop_ns()) * ->current_ns() semantics change - it's supposed to be followed by corresponding ->drop_ns(). For struct net in case of CONFIG_NET_NS it bumps the new refcount; net_drop_ns() decrements it and calls net_free() if the last reference has been dropped. Method renamed to ->grab_current_ns(). * old net_free() callers call net_drop_ns() instead. * sysfs_exit_ns() is gone, along with a large part of callchain leading to it; now that the references stored in ->ns[...] stay valid we do not need to hunt them down and replace them with NULL. That fixes problems in sysfs_lookup() and sysfs_readdir(), along with getting rid of sb->s_instances abuse. Note that struct net *shutdown* logics has not changed - net_cleanup() is called exactly when it used to be called. The only thing postponed by having a sysfs instance refering to that struct net is actual freeing of memory occupied by struct net. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-13sysfs: remove "last sysfs file:" line from the oops messagesGreg Kroah-Hartman
On some arches (x86, sh, arm, unicore, powerpc) the oops message would print out the last sysfs file accessed. This was very useful in finding a number of sysfs and driver core bugs in the 2.5 and early 2.6 development days, but it has been a number of years since this file has actually helped in debugging anything that couldn't also be trivially determined from the stack traceback. So it's time to delete the line. This is good as we need all the space we can get for oops messages at times on consoles. Acked-by: Phil Carmody <ext-phil.2.carmody@nokia.com> Acked-by: Ingo Molnar <mingo@elte.hu> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-10-17sysfs: Add sysfs_merge_group() and sysfs_unmerge_group()Alan Stern
This patch (as1420) adds sysfs_merge_group() and sysfs_unmerge_group() functions, allowing drivers easily to add and remove sets of attributes to a pre-existing attribute group directory. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2010-08-23kobject: Break the kobject namespace defs into their own headerDavid Howells
Break the kobject namespace defs into their own header to avoid a header file inclusion ordering problem between linux/sysfs.h and linux/kobject.h. This fixes the build breakage on older versions of gcc. Signed-off-by: David Howells <dhowells@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-05sysfs: Remove owner field from sysfs struct attributeGuenter Roeck
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-08-05sysfs: sysfs_chmod_file's attr can be constJean Delvare
sysfs_chmod_file doesn't change the attribute it operates on, so this attribute can be marked const. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: add struct file* to bin_attr callbacksChris Wright
This allows bin_attr->read,write,mmap callbacks to check file specific data (such as inode owner) as part of any privilege validation. Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Don't use enums in inline function declaration.Eric W. Biederman
It appears gcc can't cope with using an enum that is only declared in an inline function declaration, that doesn't even use the variable that is so declared. Avoid the silliness and replace the enum with an int, and make gcc happy. Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Acked-by: Randy Dunlap <randy.dunlap@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Comment sysfs directory tagging logicSerge E. Hallyn
Add some in-line comments to explain the new infrastructure, which was introduced to support sysfs directory tagging with namespaces. I think an overall description someplace might be good too, but it didn't really seem to fit into Documentation/filesystems/sysfs.txt, which appears more geared toward users, rather than maintainers, of sysfs. (Tejun, please let me know if I can make anything clearer or failed altogether to comment something that should be commented.) Signed-off-by: Serge E. Hallyn <serue@us.ibm.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Implement sysfs_delete_linkEric W. Biederman
When removing a symlink sysfs_remove_link does not provide enough information to figure out which tagged directory the symlink falls in. So I need sysfs_delete_link which is passed the target of the symlink to delete. sysfs_rename_link is updated to call sysfs_delete_link instead of sysfs_remove_link as we have all of the information necessary and the callers are interesting. Both of these functions now have enough information to find a symlink in a tagged directory. The only restriction is that they must be called before the target kobject is renamed or deleted. If they are called later I loose track of which tag the target kobject was marked with and can no longer find the old symlink to remove it. This patch was split from an earlier patch. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-05-21sysfs: Implement sysfs tagged directory support.Eric W. Biederman
The problem. When implementing a network namespace I need to be able to have multiple network devices with the same name. Currently this is a problem for /sys/class/net/*, /sys/devices/virtual/net/*, and potentially a few other directories of the form /sys/ ... /net/*. What this patch does is to add an additional tag field to the sysfs dirent structure. For directories that should show different contents depending on the context such as /sys/class/net/, and /sys/devices/virtual/net/ this tag field is used to specify the context in which those directories should be visible. Effectively this is the same as creating multiple distinct directories with the same name but internally to sysfs the result is nicer. I am calling the concept of a single directory that looks like multiple directories all at the same path in the filesystem tagged directories. For the networking namespace the set of directories whose contents I need to filter with tags can depend on the presence or absence of hotplug hardware or which modules are currently loaded. Which means I need a simple race free way to setup those directories as tagged. To achieve a reace free design all tagged directories are created and managed by sysfs itself. Users of this interface: - define a type in the sysfs_tag_type enumeration. - call sysfs_register_ns_types with the type and it's operations - sysfs_exit_ns when an individual tag is no longer valid - Implement mount_ns() which returns the ns of the calling process so we can attach it to a sysfs superblock. - Implement ktype.namespace() which returns the ns of a syfs kobject. Everything else is left up to sysfs and the driver layer. For the network namespace mount_ns and namespace() are essentially one line functions, and look to remain that. Tags are currently represented a const void * pointers as that is both generic, prevides enough information for equality comparisons, and is trivial to create for current users, as it is just the existing namespace pointer. The work needed in sysfs is more extensive. At each directory or symlink creating I need to check if the directory it is being created in is a tagged directory and if so generate the appropriate tag to place on the sysfs_dirent. Likewise at each symlink or directory removal I need to check if the sysfs directory it is being removed from is a tagged directory and if so figure out which tag goes along with the name I am deleting. Currently only directories which hold kobjects, and symlinks are supported. There is not enough information in the current file attribute interfaces to give us anything to discriminate on which makes it useless, and there are no potential users which makes it an uninteresting problem to solve. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Benjamin Thery <benjamin.thery@bull.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07sysfs: fix for thinko with sysfs_bin_attr_init()Stephen Rothwell
After merging the final tree, today's linux-next build (powerpc allyesconfig) failed like this: drivers/pci/pci-sysfs.c: In function 'pci_create_legacy_files': drivers/pci/pci-sysfs.c:645: error: lvalue required as unary '&' operand drivers/pci/pci-sysfs.c:658: error: lvalue required as unary '&' operand Caused by commit "sysfs: Use sysfs_attr_init and sysfs_bin_attr_init on dynamic attributes" interacting with commit "sysfs: Use one lockdep class per sysfs attribute") both from the driver-core tree. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07sysfs: Implement sysfs_rename_linkEric W. Biederman
Because of rename ordering problems we occassionally give false warnings about invalid sysfs operations. So using sysfs_rename create a sysfs_rename_link function that doesn't need strange workarounds. Cc: Benjamin Thery <benjamin.thery@bull.net> Cc: Daniel Lezcano <dlezcano@fr.ibm.com> Acked-by: Serge Hallyn <serue@us.ibm.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07sysfs: Document sysfs_attr_init and sysfs_bin_attr_initEric W. Biederman
I have added a new requirement to the external sysfs interface that dynamically allocated sysfs attributes must call sysfs_attr_init if lockdep is enabled. For the time being callying sysfs_attr_init is only mandatory if lockdep is enabled, so we can live with a few unconverted instances until we find them all. As this is part of the public interface of sysfs it is a good idea to document these pseudo functions so someone inspeciting the code can find out what has happened. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07sysfs: Use one lockdep class per sysfs attribute.Eric W. Biederman
Acknowledge that the logical sysfs rwsem has one instance per sysfs attribute with different locking depencencies for different attributes. There is a sysfs idiom where writing to one sysfs file causes the addition or removal of other sysfs files. Lumping all of the sysfs attributes together in one lock class causes lockdep to generate lots of false positives. This introduces the requirement that non-static sysfs attributes need to be initialized with sysfs_attr_init or sysfs_bin_attr_init. Strictly speaking this requirement only exists when lockdep is enabled, and when lockdep is enabled we get a bit fat warning if this requirement is not met. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: WANG Cong <xiyou.wangcong@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-07sysfs: Add sysfs_add/remove_files utility functionsAndi Kleen
Adding/Removing a whole array of attributes is very common. Add a standard utility function to do this with a simple function call, instead of requiring drivers to open code this. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>