kernel.git/fs/kernfs/dir.c, branch linux-3.17.y

Merge 3.15-rc3 into staging-next

2014-04-28T04:36:39Z

kernfs: fix a subdir count leak

2014-04-25T19:25:13Z

Currently kernfs_link_sibling() increates parent->dir.subdirs before adding the node into parent's chidren rb tree. Because it is possible that kernfs_link_sibling() couldn't find a suitable slot and bail out, this leads to a mismatch between elevated subdir count with actual children node numbers. This patches fix this problem, by moving the subdir accouting after the actual addtion happening. Signed-off-by: Jianyu Zhan Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

kernfs: implement kernfs_root->supers list

2014-04-25T18:43:31Z

Currently, there's no way to find out which super_blocks are associated with a given kernfs_root. Let's implement it - the planned inotify extension to kernfs_notify() needs it. Make kernfs_super_info point back to the super_block and chain it at kernfs_root->supers. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

Merge branch 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup

2014-04-03T20:05:42Z

Pull cgroup updates from Tejun Heo: "A lot updates for cgroup: - The biggest one is cgroup's conversion to kernfs. cgroup took after the long abandoned vfs-entangled sysfs implementation and made it even more convoluted over time. cgroup's internal objects were fused with vfs objects which also brought in vfs locking and object lifetime rules. Naturally, there are places where vfs rules don't fit and nasty hacks, such as credential switching or lock dance interleaving inode mutex and cgroup_mutex with object serial number comparison thrown in to decide whether the operation is actually necessary, needed to be employed. After conversion to kernfs, internal object lifetime and locking rules are mostly isolated from vfs interactions allowing shedding of several nasty hacks and overall simplification. This will also allow implmentation of operations which may affect multiple cgroups which weren't possible before as it would have required nesting i_mutexes. - Various simplifications including dropping of module support, easier cgroup name/path handling, simplified cgroup file type handling and task_cg_lists optimization. - Prepatory changes for the planned unified hierarchy, which is still a patchset away from being actually operational. The dummy hierarchy is updated to serve as the default unified hierarchy. Controllers which aren't claimed by other hierarchies are associated with it, which BTW was what the dummy hierarchy was for anyway. - Various fixes from Li and others. This pull request includes some patches to add missing slab.h to various subsystems. This was triggered xattr.h include removal from cgroup.h. cgroup.h indirectly got included a lot of files which brought in xattr.h which brought in slab.h. There are several merge commits - one to pull in kernfs updates necessary for converting cgroup (already in upstream through driver-core), others for interfering changes in the fixes branch" * 'for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (74 commits) cgroup: remove useless argument from cgroup_exit() cgroup: fix spurious lockdep warning in cgroup_exit() cgroup: Use RCU_INIT_POINTER(x, NULL) in cgroup.c cgroup: break kernfs active_ref protection in cgroup directory operations cgroup: fix cgroup_taskset walking order cgroup: implement CFTYPE_ONLY_ON_DFL cgroup: make cgrp_dfl_root mountable cgroup: drop const from @buffer of cftype->write_string() cgroup: rename cgroup_dummy_root and related names cgroup: move ->subsys_mask from cgroupfs_root to cgroup cgroup: treat cgroup_dummy_root as an equivalent hierarchy during rebinding cgroup: remove NULL checks from [pr_cont_]cgroup_{name|path}() cgroup: use cgroup_setup_root() to initialize cgroup_dummy_root cgroup: reorganize cgroup bootstrapping cgroup: relocate setting of CGRP_DEAD cpuset: use rcu_read_lock() to protect task_cs() cgroup_freezer: document freezer_fork() subtleties cgroup: update cgroup_transfer_tasks() to either succeed or fail cgroup: drop task_lock() protection around task->cgroups cgroup: update how a newly forked task gets associated with css_set ...

kernfs: fix off by one error.

2014-03-09T06:08:29Z

The hash values 0 and 1 are reserved for magic directory entries, but the code only prevents names hashing to 0. This patch fixes the test to also prevent hash value 1. Signed-off-by: Richard Cochran Cc: Reviewed-by: "Eric W. Biederman" Signed-off-by: Greg Kroah-Hartman

kernfs: fix kernfs_node_from_dentry()

2014-02-14T22:31:37Z

Currently kernfs_node_from_dentry() returns NULL for root dentry, because root_dentry->d_op == NULL. Due to this bug cgroupstats_build() returns -EINVAL for root cgroup. # mount -t cgroup -o cpuacct /cgroup # Documentation/accounting/getdelays -C /cgroup fatal reply error, errno -22 With this fix: # Documentation/accounting/getdelays -C /cgroup sleeping 305, blocked 0, running 1, stopped 0, uninterruptible 1 Signed-off-by: Li Zefan Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

cgroup: remove cgroup->name

2014-02-12T14:29:50Z

cgroup->name handling became quite complicated over time involving dedicated struct cgroup_name for RCU protection. Now that cgroup is on kernfs, we can drop all of it and simply use kernfs_name/path() and friends. Replace cgroup->name and all related code with kernfs name/path constructs. * Reimplement cgroup_name() and cgroup_path() as thin wrappers on top of kernfs counterparts, which involves semantic changes. pr_cont_cgroup_name() and pr_cont_cgroup_path() added. * cgroup->name handling dropped from cgroup_rename(). * All users of cgroup_name/path() updated to the new semantics. Users which were formatting the string just to printk them are converted to use pr_cont_cgroup_name/path() instead, which simplifies things quite a bit. As cgroup_name() no longer requires RCU read lock around it, RCU lockings which were protecting only cgroup_name() are removed. v2: Comment above oom_info_lock updated as suggested by Michal. v3: dummy_top doesn't have a kn associated and pr_cont_cgroup_name/path() ended up calling the matching kernfs functions with NULL kn leading to oops. Test for NULL kn and print "/" if so. This issue was reported by Fengguang Wu. v4: Rebased on top of 0ab02ca8f887 ("cgroup: protect modifications to cgroup_idr with cgroup_mutex"). Signed-off-by: Tejun Heo Acked-by: Peter Zijlstra Acked-by: Michal Hocko Acked-by: Li Zefan Cc: Fengguang Wu Cc: Ingo Molnar Cc: Johannes Weiner Cc: Balbir Singh Cc: KAMEZAWA Hiroyuki

kernfs: fix hash calculation in kernfs_rename_ns()

2014-02-11T00:00:19Z

3eef34ad7dc3 ("kernfs: implement kernfs_get_parent(), kernfs_name/path() and friends") restructured kernfs_rename_ns() such that new name assignment happens under kernfs_rename_lock; unfortunately, it mistakenly passed NULL to kernfs_name_hash() to calculate the new hash if the name hasn't changed, which can lead to oops. Fix it by using kn->name and kn->ns when calculating the new hash. Signed-off-by: Tejun Heo Reported-by: Dan Carpenter dan.carpenter@oracle.com Signed-off-by: Greg Kroah-Hartman

kernfs: implement kernfs_get_parent(), kernfs_name/path() and friends

2014-02-08T00:05:35Z

kernfs_node->parent and ->name are currently marked as "published" indicating that kernfs users may access them directly; however, those fields may get updated by kernfs_rename[_ns]() and unrestricted access may lead to erroneous values or oops. Protect ->parent and ->name updates with a irq-safe spinlock kernfs_rename_lock and implement the following accessors for these fields. * kernfs_name() - format the node's name into the specified buffer * kernfs_path() - format the node's path into the specified buffer * pr_cont_kernfs_name() - pr_cont a node's name (doesn't need buffer) * pr_cont_kernfs_path() - pr_cont a node's path (doesn't need buffer) * kernfs_get_parent() - pin and return a node's parent All can be called under any context. The recursive sysfs_pathname() in fs/sysfs/dir.c is replaced with kernfs_path() and sysfs_rename_dir_ns() is updated to use kernfs_get_parent() instead of dereferencing parent directly. v2: Dummy definition of kernfs_path() for !CONFIG_KERNFS was missing static inline making it cause a lot of build warnings. Add it. Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman

kernfs: implement kernfs_node_from_dentry(), kernfs_root_from_sb() and kernfs_rename()

2014-02-08T00:00:41Z

Implement helpers to determine node from dentry and root from super_block. Also add a kernfs_rename_ns() wrapper which assumes NULL namespace. These generally make sense and will be used by cgroup. v2: Some dummy implementations for !CONFIG_SYSFS was missing. Fixed. Reported by kbuild test robot. Signed-off-by: Tejun Heo Cc: kbuild test robot Signed-off-by: Greg Kroah-Hartman