Searched +hist:23 +hist:bf1b6b (Results 1 - 8 of 8) sorted by relevance
/linux-master/kernel/cgroup/ | ||
H A D | cgroup-internal.h | diff 6a010a49 Sat Jul 23 08:28:28 MDT 2022 Tejun Heo <tj@kernel.org> cgroup: Make !percpu threadgroup_rwsem operations optional 3942a9bd7b58 ("locking, rcu, cgroup: Avoid synchronize_sched() in __cgroup_procs_write()") disabled percpu operations on threadgroup_rwsem because the impiled synchronize_rcu() on write locking was pushing up the latencies too much for android which constantly moves processes between cgroups. This makes the hotter paths - fork and exit - slower as they're always forced into the slow path. There is no reason to force this on everyone especially given that more common static usage pattern can now completely avoid write-locking the rwsem. Write-locking is elided when turning on and off controllers on empty sub-trees and CLONE_INTO_CGROUP enables seeding a cgroup without grabbing the rwsem. Restore the default percpu operations and introduce the mount option "favordynmods" and config option CGROUP_FAVOR_DYNMODS for users who need lower latencies for the dynamic operations. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Michal Koutn� <mkoutny@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Oleg Nesterov <oleg@redhat.com> diff 29ed1738 Tue May 17 05:25:23 MDT 2022 Xiu Jianfeng <xiujianfeng@huawei.com> cgroup: Make cgroup_debug static Make cgroup_debug static since it's only used in cgroup.c Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org> diff d7167b14 Sat Sep 07 05:23:15 MDT 2019 Al Viro <viro@zeniv.linux.org.uk> fs_parse: fold fs_parameter_desc/fs_parameter_spec The former contains nothing but a pointer to an array of the latter... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 7feeef58 Wed Jan 16 19:23:02 MST 2019 Al Viro <viro@zeniv.linux.org.uk> cgroup: fold cgroup1_mount() into cgroup1_get_tree() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 3f3942ac Tue May 15 07:57:23 MDT 2018 Christoph Hellwig <hch@lst.de> proc: introduce proc_create_single{,_data} Variants of proc_create{,_data} that directly take a seq_file show callback and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig <hch@lst.de> diff d41bf8c9 Mon Oct 23 17:18:27 MDT 2017 Tejun Heo <tj@kernel.org> cgroup, sched: Move basic cpu stats from cgroup.stat to cpu.stat The basic cpu stat is currently shown with "cpu." prefix in cgroup.stat, and the same information is duplicated in cpu.stat when cpu controller is enabled. This is ugly and not very scalable as we want to expand the coverage of stat information which is always available. This patch makes cgroup core always create "cpu.stat" file and show the basic cpu stat there and calls the cpu controller to show the extra stats when enabled. This ensures that the same information isn't presented in multiple places and makes future expansion of basic stats easier. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> |
H A D | cgroup.c | diff c25ff4b9 Mon Jul 17 08:39:23 MDT 2023 Kamalesh Babulal <kamalesh.babulal@oracle.com> cgroup: remove cgrp->kn check in css_populate_dir() cgroup_create() creates cgrp and assigns the kernfs_node to cgrp->kn, then cgroup_mkdir() populates base and csses cft file by calling css_populate_dir() and cgroup_apply_control_enable() with a valid cgrp->kn. Check for NULL cgrp->kn, will always be false, remove it. Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com> Signed-off-by: Tejun Heo <tj@kernel.org> diff 674b745e Wed Nov 23 07:45:14 MST 2022 Ran Tian <tianran_trtr@163.com> cgroup: remove rcu_read_lock()/rcu_read_unlock() in critical section of spin_lock_irq() spin_lock_irq() already disable preempt, so remove rcu_read_lock(). Signed-off-by: Ran Tian <tianran_trtr@163.com> Signed-off-by: Tejun Heo <tj@kernel.org> diff 7e1eb543 Fri Sep 23 11:23:06 MDT 2022 Tejun Heo <tj@kernel.org> cgroup: Make cgroup_get_from_id() prettier After merging 836ac87d ("cgroup: fix cgroup_get_from_id") into for-6.1, its combination with two commits in for-6.1 - 4534dee9 ("cgroup: cgroup: Honor caller's cgroup NS when resolving cgroup id") and fa7e439c ("cgroup: Homogenize cgroup_get_from_id() return value") - makes the gotos in the error handling path too ugly while not adding anything of value. All that the gotos are saving is one extra kernfs_put() call. Let's remove the gotos and perform error returns directly. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Michal Koutný <mkoutny@suse.com> diff 7e1eb543 Fri Sep 23 11:23:06 MDT 2022 Tejun Heo <tj@kernel.org> cgroup: Make cgroup_get_from_id() prettier After merging 836ac87d ("cgroup: fix cgroup_get_from_id") into for-6.1, its combination with two commits in for-6.1 - 4534dee9 ("cgroup: cgroup: Honor caller's cgroup NS when resolving cgroup id") and fa7e439c ("cgroup: Homogenize cgroup_get_from_id() return value") - makes the gotos in the error handling path too ugly while not adding anything of value. All that the gotos are saving is one extra kernfs_put() call. Let's remove the gotos and perform error returns directly. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Ming Lei <ming.lei@redhat.com> Cc: Michal Koutný <mkoutny@suse.com> diff e2691f6b Sat Aug 27 23:04:40 MDT 2022 Tejun Heo <tj@kernel.org> cgroup: Implement cgroup_file_show() Add cgroup_file_show() which allows toggling visibility of a cgroup file using the new kernfs_show(). This will be used to hide psi interface files on cgroups where it's disabled. Cc: Chengming Zhou <zhouchengming@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20220828050440.734579-10-tj@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff df02452f Fri Sep 23 05:51:19 MDT 2022 Ming Lei <ming.lei@redhat.com> cgroup: cgroup_get_from_id() must check the looked-up kn is a directory cgroup has to be one kernfs dir, otherwise kernel panic is caused, especially cgroup id is provide from userspace. Reported-by: Marco Patalano <mpatalan@redhat.com> Fixes: 6b658c4863c1 ("scsi: cgroup: Add cgroup_get_from_id()") Cc: Muneendra <muneendra.kumar@broadcom.com> Signed-off-by: Ming Lei <ming.lei@redhat.com> Acked-by: Mukesh Ojha <quic_mojha@quicinc.com> Cc: stable@vger.kernel.org # v5.14+ Signed-off-by: Tejun Heo <tj@kernel.org> diff 763f4fb7 Mon Aug 22 23:41:46 MDT 2022 Jing-Ting Wu <Jing-Ting.Wu@mediatek.com> cgroup: Fix race condition at rebind_subsystems() Root cause: The rebind_subsystems() is no lock held when move css object from A list to B list,then let B's head be treated as css node at list_for_each_entry_rcu(). Solution: Add grace period before invalidating the removed rstat_css_node. Reported-by: Jing-Ting Wu <jing-ting.wu@mediatek.com> Suggested-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Jing-Ting Wu <jing-ting.wu@mediatek.com> Tested-by: Jing-Ting Wu <jing-ting.wu@mediatek.com> Link: https://lore.kernel.org/linux-arm-kernel/d8f0bc5e2fb6ed259f9334c83279b4c011283c41.camel@mediatek.com/T/ Acked-by: Mukesh Ojha <quic_mojha@quicinc.com> Fixes: a7df69b81aac ("cgroup: rstat: support cgroup1") Cc: stable@vger.kernel.org # v5.13+ Signed-off-by: Tejun Heo <tj@kernel.org> diff 6a010a49 Sat Jul 23 08:28:28 MDT 2022 Tejun Heo <tj@kernel.org> cgroup: Make !percpu threadgroup_rwsem operations optional 3942a9bd7b58 ("locking, rcu, cgroup: Avoid synchronize_sched() in __cgroup_procs_write()") disabled percpu operations on threadgroup_rwsem because the impiled synchronize_rcu() on write locking was pushing up the latencies too much for android which constantly moves processes between cgroups. This makes the hotter paths - fork and exit - slower as they're always forced into the slow path. There is no reason to force this on everyone especially given that more common static usage pattern can now completely avoid write-locking the rwsem. Write-locking is elided when turning on and off controllers on empty sub-trees and CLONE_INTO_CGROUP enables seeding a cgroup without grabbing the rwsem. Restore the default percpu operations and introduce the mount option "favordynmods" and config option CGROUP_FAVOR_DYNMODS for users who need lower latencies for the dynamic operations. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Michal Koutn� <mkoutny@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Oleg Nesterov <oleg@redhat.com> diff d75cd55a Tue Jun 21 03:23:58 MDT 2022 Lin Feng <linf@wangsu.com> cgroup.c: remove redundant check for mixable cgroup in cgroup_migrate_vet_dst We have: int cgroup_migrate_vet_dst(struct cgroup *dst_cgrp) { ... /* mixables don't care */ if (cgroup_is_mixable(dst_cgrp)) return 0; /* * If @dst_cgrp is already or can become a thread root or is * threaded, it doesn't matter. */ if (cgroup_can_be_thread_root(dst_cgrp) || cgroup_is_threaded(dst_cgrp)) return 0; ... } but in fact the entry of cgroup_can_be_thread_root() covers case that checking cgroup_is_mixable() as following: static bool cgroup_can_be_thread_root(struct cgroup *cgrp) { /* mixables don't care */ if (cgroup_is_mixable(cgrp)) return true; ... } so explicitly checking in cgroup_migrate_vet_dst is unnecessary. Signed-off-by: Lin Feng <linf@wangsu.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org> diff 29ed1738 Tue May 17 05:25:23 MDT 2022 Xiu Jianfeng <xiujianfeng@huawei.com> cgroup: Make cgroup_debug static Make cgroup_debug static since it's only used in cgroup.c Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org> |
/linux-master/fs/sysfs/ | ||
H A D | mount.c | diff ab81dabd Sat Mar 16 07:45:42 MDT 2019 Al Viro <viro@zeniv.linux.org.uk> fix sysfs_init_fs_context() in !CONFIG_NET_NS case Permission checks on current's netns should be done only when netns are enabled. Reported-by: Dominik Brodowski <linux@dominikbrodowski.net> Fixes: 23bf1b6be9c2 Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff c84a3b27 Sat Nov 23 16:01:46 MST 2013 Tejun Heo <tj@kernel.org> sysfs: drop kobj_ns_type handling, take #2 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> diff 04256b4a Wed Feb 11 14:20:23 MST 2009 Eric W. Biederman <ebiederm@aristanetworks.com> sysfs: reference sysfs_dirent from sysfs inodes The sysfs_dirent serves as both an inode and a directory entry for sysfs. To prevent the sysfs inode numbers from being freed prematurely hold a reference to sysfs_dirent from the sysfs inode. [akpm@linux-foundation.org: add comment] Signed-off-by: Eric W. Biederman <ebiederm@aristanetworks.com> Cc: Tejun Heo <tj@kernel.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> diff e080e436 Tue Jul 17 23:29:06 MDT 2007 Tejun Heo <htejun@gmail.com> sysfs: fix sysfs root inode nlink accounting While making sysfs indoes hashed, sysfs root inode was left out. Now that nlink accounting depends on the inode being on the hash, sysfs root inode nlink isn't adjusted properly. Put sysfs root inode on the inode hash by allocating it using sysfs_get_inode() like other sysfs inodes. While at it, massage comments a bit. Signed-off-by: Tejun Heo <htejun@gmail.com> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> diff dc351252 Sun Jun 10 23:02:45 MDT 2007 Eric Sandeen <sandeen@sandeen.net> sysfs: store sysfs inode nrs in s_ino to avoid readdir oopses Backport of ftp://ftp.kernel.org/pub/linux/kernel/people/akpm/patches/2.6/2.6.22-rc1/2.6.22-rc1-mm1/broken-out/gregkh-driver-sysfs-allocate-inode-number-using-ida.patch For regular files in sysfs, sysfs_readdir wants to traverse sysfs_dirent->s_dentry->d_inode->i_ino to get to the inode number. But, the dentry can be reclaimed under memory pressure, and there is no synchronization with readdir. This patch follows Tejun's scheme of allocating and storing an inode number in the new s_ino member of a sysfs_dirent, when dirents are created, and retrieving it from there for readdir, so that the pointer chain doesn't have to be traversed. Tejun's upstream patch uses a new-ish "ida" allocator which brings along some extra complexity; this -stable patch has a brain-dead incrementing counter which does not guarantee uniqueness, but because sysfs doesn't hash inodes as iunique expects, uniqueness wasn't guaranteed today anyway. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Tejun Heo <htejun@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> diff 454e2398 Fri Jun 23 03:02:57 MDT 2006 David Howells <dhowells@redhat.com> [PATCH] VFS: Permit filesystem to override root dentry on mount Extend the get_sb() filesystem operation to take an extra argument that permits the VFS to pass in the target vfsmount that defines the mountpoint. The filesystem is then required to manually set the superblock and root dentry pointers. For most filesystems, this should be done with simple_set_mnt() which will set the superblock pointer and then set the root dentry to the superblock's s_root (as per the old default behaviour). The get_sb() op now returns an integer as there's now no need to return the superblock pointer. This patch permits a superblock to be implicitly shared amongst several mount points, such as can be done with NFS to avoid potential inode aliasing. In such a case, simple_set_mnt() would not be called, and instead the mnt_root and mnt_sb would be set directly. The patch also makes the following changes: (*) the get_sb_*() convenience functions in the core kernel now take a vfsmount pointer argument and return an integer, so most filesystems have to change very little. (*) If one of the convenience function is not used, then get_sb() should normally call simple_set_mnt() to instantiate the vfsmount. This will always return 0, and so can be tail-called from get_sb(). (*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the dcache upon superblock destruction rather than shrink_dcache_anon(). This is required because the superblock may now have multiple trees that aren't actually bound to s_root, but that still need to be cleaned up. The currently called functions assume that the whole tree is rooted at s_root, and that anonymous dentries are not the roots of trees which results in dentries being left unculled. However, with the way NFS superblock sharing are currently set to be implemented, these assumptions are violated: the root of the filesystem is simply a dummy dentry and inode (the real inode for '/' may well be inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries with child trees. [*] Anonymous until discovered from another tree. (*) The documentation has been adjusted, including the additional bit of changing ext2_* into foo_* in the documentation. [akpm@osdl.org: convert ipath_fs, do other stuff] Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Nathan Scott <nathans@sgi.com> Cc: Roland Dreier <rolandd@cisco.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org> diff 8215534c Mon May 30 23:09:52 MDT 2005 Maneesh Soni <maneesh@in.ibm.com> [PATCH] sysfs-iattr: set inode attributes o Following patch sets the attributes for newly allocated inodes for sysfs objects. If the object has non-default attributes, inode attributes are set as saved in sysfs_dirent->s_iattr, pointer to struct iattr. Signed-off-by: Maneesh Soni <maneesh@in.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
/linux-master/fs/kernfs/ | ||
H A D | kernfs-internal.h | diff ffb2e065 Fri Sep 29 23:00:21 MDT 2023 Wedson Almeida Filho <walmeida@microsoft.com> kernfs: move kernfs_xattr_handlers to .rodata This makes it harder for accidental or malicious changes to kernfs_xattr_handlers at runtime. Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230930050033.41174-18-wedsonaf@gmail.com Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Christian Brauner <brauner@kernel.org> diff bdb2fd7f Sat Aug 27 23:04:35 MDT 2022 Tejun Heo <tj@kernel.org> kernfs: Skip kernfs_drain_open_files() more aggressively Track the number of mmapped files and files that need to be released and skip kernfs_drain_open_file() if both are zero, which are the precise conditions which require draining open_files. The early exit test is factored into kernfs_should_drain_open_files() which is now tested by kernfs_drain_open_files()'s caller - kernfs_drain(). This isn't a meaningful optimization on its own but will enable future stand-alone kernfs_deactivate() implementation. v2: Chengming noticed that on->nr_to_release was leaking after ->open() failure. Fix it by telling kernfs_unlink_open_file() that it's called from the ->open() fail path and should dec the counter. Use kzalloc() to allocate kernfs_open_node so that the tracking fields are correctly initialized. Cc: Chengming Zhou <zhouchengming@bytedance.com> Tested-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20220828050440.734579-5-tj@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff f601f9a2 Fri Jan 10 06:57:23 MST 2014 Tejun Heo <tj@kernel.org> kernfs: invoke kernfs_unmap_bin_file() directly from __kernfs_remove() kernfs_unmap_bin_file() is supposed to unmap all memory mappings of the target file before kernfs_remove() finishes; however, it currently is being called from kernfs_addrm_finish() and has the same race problem as the original implementation of deactivation when there are multiple removers - only the remover which snatches the node to its addrm_cxt->removed list is guaranteed to wait for its completion before returning. It can be fixed by moving kernfs_unmap_bin_file() invocation from kernfs_addrm_finish() to __kernfs_remove(). The function may be called multiple times but that shouldn't do any harm. We end up dropping kernfs_mutex in the removal loop and the node may be removed inbetween by someone else. kernfs_unlink_sibling() is updated to test whether the node has already been removed and return accordingly. __kernfs_remove() in turn performs post-unlinking cleanup only if it actually unlinked the node. KERNFS_HAS_MMAP test is moved out of the unmap function into __kernfs_remove() so that we don't unlock kernfs_mutex unnecessarily. While at it, drop the now meaningless "bin" qualifier from the function name. v2: Rewritten to fit the v2 restructuring of removal path. HAS_MMAP test relocated. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff 2322392b Sat Nov 23 15:40:02 MST 2013 Tejun Heo <tj@kernel.org> kernfs: implement "trusted.*" xattr support kernfs inherited "security.*" xattr support from sysfs. This patch extends xattr support to "trusted.*" using simple_xattr_*(). As trusted xattrs are restricted to CAP_SYS_ADMIN, simple_xattr_*() which uses kernel memory for storage shouldn't be problematic. Note that the existing "security.*" support doesn't implement get/remove/list and the this patch only implements those ops for "trusted.*". We probably want to extend those ops to include support for "security.*". This patch will allow using kernfs from cgroup which requires "trusted.*" xattr support. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: David P. Quigley <dpquigl@tycho.nsa.gov> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff 9a8049af Sat Nov 23 15:40:01 MST 2013 Tejun Heo <tj@kernel.org> kernfs: update sysfs_init_inode_attrs() sysfs_init_inode_attrs() is a bit clumsy to use requiring the caller to check whether @sd->s_iattr is already set or not. Rename it to sysfs_inode_attrs(), update it to check whether @sd->s_iattr is already initialized before trying to initialize it and return @sd->s_iattr. This simplifies the callers. While at it, * Rename struct sysfs_inode_attrs pointer variables to "attrs". As kernfs no longer deals with "struct attribute", this isn't confusing and makes it easier to distinguish from struct iattr pointers. * A new field will be added to sysfs_inode_attrs. Reindent in preparation. 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> |
H A D | mount.c | diff 6c2d4798 Wed Oct 30 23:21:58 MDT 2019 Al Viro <viro@zeniv.linux.org.uk> new helper: lookup_positive_unlocked() Most of the callers of lookup_one_len_unlocked() treat negatives are ERR_PTR(-ENOENT). Provide a helper that would do just that. Note that a pinned positive dentry remains positive - it's ->d_inode is stable, etc.; a pinned _negative_ dentry can become positive at any point as long as you are not holding its parent at least shared. So using lookup_one_len_unlocked() needs to be careful; lookup_positive_unlocked() is safer and that's what the callers end up open-coding anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 3cc9b23c Wed May 11 23:29:45 MDT 2016 Serge E. Hallyn <serge.hallyn@ubuntu.com> kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry call Our caller expects 0 on success, not >0. This fixes a bug in the patch cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces where /sys does not show up in mountinfo, breaking criu. Thanks for catching this, Andrei. Reported-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: Tejun Heo <tj@kernel.org> |
/linux-master/arch/x86/kernel/cpu/resctrl/ | ||
H A D | internal.h | diff 4cee14bc Mon Oct 16 18:23:08 MDT 2023 Babu Moger <babu.moger@amd.com> x86/resctrl: Display RMID of resource group In x86, hardware uses RMID to identify a monitoring group. When a user creates a monitor group these details are not visible. These details can help resctrl debugging. Add RMID(mon_hw_id) to the monitor groups display in the resctrl interface. Users can see these details when resctrl is mounted with "-o debug" option. Add RFTYPE_MON_BASE that complements existing RFTYPE_CTRL_BASE and represents files belonging to monitoring groups. Other architectures do not use "RMID". Use the name mon_hw_id to refer to "RMID" in an effort to keep the naming generic. For example: $cat /sys/fs/resctrl/mon_groups/mon_grp1/mon_hw_id 3 Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Newman <peternewman@google.com> Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Link: https://lore.kernel.org/r/20231017002308.134480-10-babu.moger@amd.com diff cb07d71f Mon Oct 16 18:23:05 MDT 2023 Babu Moger <babu.moger@amd.com> x86/resctrl: Introduce "-o debug" mount option Add "-o debug" option to mount resctrl filesystem in debug mode. When in debug mode resctrl displays files that have the new RFTYPE_DEBUG flag to help resctrl debugging. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Newman <peternewman@google.com> Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Link: https://lore.kernel.org/r/20231017002308.134480-7-babu.moger@amd.com diff d4159243 Mon Oct 16 18:23:02 MDT 2023 Babu Moger <babu.moger@amd.com> x86/resctrl: Rename rftype flags for consistency resctrl associates rftype flags with its files so that files can be chosen based on the resource, whether it is info or base, and if it is control or monitor type file. These flags use the RF_ as well as RFTYPE_ prefixes. Change the prefix to RFTYPE_ for all these flags to be consistent. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Newman <peternewman@google.com> Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Link: https://lore.kernel.org/r/20231017002308.134480-4-babu.moger@amd.com diff 4d044c52 Fri Sep 02 09:48:23 MDT 2022 James Morse <james.morse@arm.com> x86/resctrl: Abstract __rmid_read() __rmid_read() selects the specified eventid and returns the counter value from the MSR. The error handling is architecture specific, and handled by the callers, rdtgroup_mondata_show() and __mon_event_count(). Error handling should be handled by architecture specific code, as a different architecture may have different requirements. MPAM's counters can report that they are 'not ready', requiring a second read after a short delay. This should be hidden from resctrl. Make __rmid_read() the architecture specific function for reading a counter. Rename it resctrl_arch_rmid_read() and move the error handling into it. A read from a counter that hardware supports but resctrl does not now returns -EINVAL instead of -EIO from the default case in __mon_event_count(). It isn't possible for user-space to see this change as resctrl doesn't expose counters it doesn't support. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jamie Iles <quic_jiles@quicinc.com> Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Xin Hao <xhao@linux.alibaba.com> Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com> Tested-by: Cristian Marussi <cristian.marussi@arm.com> Link: https://lore.kernel.org/r/20220902154829.30399-16-james.morse@arm.com diff 32150edd Wed Jul 28 11:06:23 MDT 2021 James Morse <james.morse@arm.com> x86/resctrl: Swizzle rdt_resource and resctrl_schema in pseudo_lock_region struct pseudo_lock_region points to the rdt_resource. Once the resources are merged, this won't be unique. The resource name is moving into the schema, so that the filesystem portions of resctrl can generate it. Swap pseudo_lock_region's rdt_resource pointer for a schema pointer. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jamie Iles <jamie@nuviainc.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Babu Moger <babu.moger@amd.com> Link: https://lkml.kernel.org/r/20210728170637.25610-11-james.morse@arm.com diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> |
H A D | rdtgroup.c | diff 258c91e8 Tue Feb 13 11:44:36 MST 2024 James Morse <james.morse@arm.com> x86/resctrl: Add CPU offline callback for resctrl work The resctrl architecture specific code may need to free a domain when a CPU goes offline, it also needs to reset the CPUs PQR_ASSOC register. Amongst other things, the resctrl filesystem code needs to clear this CPU from the cpu_mask of any control and monitor groups. Currently, this is all done in core.c and called from resctrl_offline_cpu(), making the split between architecture and filesystem code unclear. Move the filesystem work to remove the CPU from the control and monitor groups into a filesystem helper called resctrl_offline_cpu(), and rename the one in core.c resctrl_arch_offline_cpu(). Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Babu Moger <babu.moger@amd.com> Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Babu Moger <babu.moger@amd.com> Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64 Link: https://lore.kernel.org/r/20240213184438.16675-23-james.morse@arm.com Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> diff 5d920b68 Tue Feb 13 11:44:23 MST 2024 James Morse <james.morse@arm.com> x86/resctrl: Use __set_bit()/__clear_bit() instead of open coding The resctrl CLOSID allocator uses a single 32bit word to track which CLOSID are free. The setting and clearing of bits is open coded. Convert the existing open coded bit manipulations of closid_free_map to use __set_bit() and friends. These don't need to be atomic as this list is protected by the mutex. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Babu Moger <babu.moger@amd.com> Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Babu Moger <babu.moger@amd.com> Tested-by: Carl Worth <carl@os.amperecomputing.com> # arm64 Link: https://lore.kernel.org/r/20240213184438.16675-10-james.morse@arm.com Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> diff 4cee14bc Mon Oct 16 18:23:08 MDT 2023 Babu Moger <babu.moger@amd.com> x86/resctrl: Display RMID of resource group In x86, hardware uses RMID to identify a monitoring group. When a user creates a monitor group these details are not visible. These details can help resctrl debugging. Add RMID(mon_hw_id) to the monitor groups display in the resctrl interface. Users can see these details when resctrl is mounted with "-o debug" option. Add RFTYPE_MON_BASE that complements existing RFTYPE_CTRL_BASE and represents files belonging to monitoring groups. Other architectures do not use "RMID". Use the name mon_hw_id to refer to "RMID" in an effort to keep the naming generic. For example: $cat /sys/fs/resctrl/mon_groups/mon_grp1/mon_hw_id 3 Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Newman <peternewman@google.com> Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Link: https://lore.kernel.org/r/20231017002308.134480-10-babu.moger@amd.com diff 918f211b Mon Oct 16 18:23:07 MDT 2023 Babu Moger <babu.moger@amd.com> x86/resctrl: Add support for the files of MON groups only Files unique to monitoring groups have the RFTYPE_MON flag. When a new monitoring group is created the resctrl files with flags RFTYPE_BASE (files common to all resource groups) and RFTYPE_MON (files unique to monitoring groups) are created to support interacting with the new monitoring group. A resource group can support both monitoring and control, also termed a CTRL_MON resource group. CTRL_MON groups should get both monitoring and control resctrl files but that is not the case. Only the RFTYPE_BASE and RFTYPE_CTRL files are created for CTRL_MON groups. Ensure that files with the RFTYPE_MON flag are created for CTRL_MON groups. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Newman <peternewman@google.com> Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Link: https://lore.kernel.org/r/20231017002308.134480-9-babu.moger@amd.com diff ca8dad22 Mon Oct 16 18:23:06 MDT 2023 Babu Moger <babu.moger@amd.com> x86/resctrl: Display CLOSID for resource group In x86, hardware uses CLOSID to identify a control group. When a user creates a control group this information is not visible to the user. It can help resctrl debugging. Add CLOSID(ctrl_hw_id) to the control groups display in the resctrl interface. Users can see this detail when resctrl is mounted with the "-o debug" option. Other architectures do not use "CLOSID". Use the names ctrl_hw_id to refer to "CLOSID" in an effort to keep the naming generic. For example: $cat /sys/fs/resctrl/ctrl_grp1/ctrl_hw_id 1 Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Newman <peternewman@google.com> Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Link: https://lore.kernel.org/r/20231017002308.134480-8-babu.moger@amd.com diff cb07d71f Mon Oct 16 18:23:05 MDT 2023 Babu Moger <babu.moger@amd.com> x86/resctrl: Introduce "-o debug" mount option Add "-o debug" option to mount resctrl filesystem in debug mode. When in debug mode resctrl displays files that have the new RFTYPE_DEBUG flag to help resctrl debugging. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Newman <peternewman@google.com> Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Link: https://lore.kernel.org/r/20231017002308.134480-7-babu.moger@amd.com diff d27567a0 Mon Oct 16 18:23:04 MDT 2023 Babu Moger <babu.moger@amd.com> x86/resctrl: Move default group file creation to mount The default resource group and its files are created during kernel init time. Upcoming changes will make some resctrl files optional based on a mount parameter. If optional files are to be added to the default group based on the mount option, then each new file needs to be created separately and call kernfs_activate() again. Create all files of the default resource group during resctrl mount, destroyed during unmount, to avoid scattering resctrl file addition across two separate code flows. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Newman <peternewman@google.com> Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Link: https://lore.kernel.org/r/20231017002308.134480-6-babu.moger@amd.com diff df5f3a1d Mon Oct 16 18:23:03 MDT 2023 Babu Moger <babu.moger@amd.com> x86/resctrl: Unwind properly from rdt_enable_ctx() rdt_enable_ctx() enables the features provided during resctrl mount. Additions to rdt_enable_ctx() are required to also modify error paths of rdt_enable_ctx() callers to ensure correct unwinding if errors are encountered after calling rdt_enable_ctx(). This is error prone. Introduce rdt_disable_ctx() to refactor the error unwinding of rdt_enable_ctx() to simplify future additions. This also simplifies cleanup in rdt_kill_sb(). Suggested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Newman <peternewman@google.com> Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Link: https://lore.kernel.org/r/20231017002308.134480-5-babu.moger@amd.com diff d4159243 Mon Oct 16 18:23:02 MDT 2023 Babu Moger <babu.moger@amd.com> x86/resctrl: Rename rftype flags for consistency resctrl associates rftype flags with its files so that files can be chosen based on the resource, whether it is info or base, and if it is control or monitor type file. These flags use the RF_ as well as RFTYPE_ prefixes. Change the prefix to RFTYPE_ for all these flags to be consistent. Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Newman <peternewman@google.com> Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Link: https://lore.kernel.org/r/20231017002308.134480-4-babu.moger@amd.com diff fe2a20ea Mon Oct 16 18:23:00 MDT 2023 Babu Moger <babu.moger@amd.com> x86/resctrl: Add multiple tasks to the resctrl group at once The resctrl task assignment for monitor or control group needs to be done one at a time. For example: $mount -t resctrl resctrl /sys/fs/resctrl/ $mkdir /sys/fs/resctrl/ctrl_grp1 $echo 123 > /sys/fs/resctrl/ctrl_grp1/tasks $echo 456 > /sys/fs/resctrl/ctrl_grp1/tasks $echo 789 > /sys/fs/resctrl/ctrl_grp1/tasks This is not user-friendly when dealing with hundreds of tasks. Support multiple task assignment in one command with tasks ids separated by commas. For example: $echo 123,456,789 > /sys/fs/resctrl/ctrl_grp1/tasks Signed-off-by: Babu Moger <babu.moger@amd.com> Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de> Reviewed-by: Peter Newman <peternewman@google.com> Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Reviewed-by: Fenghua Yu <fenghua.yu@intel.com> Reviewed-by: Reinette Chatre <reinette.chatre@intel.com> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com> Tested-by: Peter Newman <peternewman@google.com> Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com> Link: https://lore.kernel.org/r/20231017002308.134480-2-babu.moger@amd.com |
/linux-master/include/linux/ | ||
H A D | kernfs.h | diff 783bd07d Sat Aug 27 23:04:39 MDT 2022 Tejun Heo <tj@kernel.org> kernfs: Implement kernfs_show() Currently, kernfs nodes can be created hidden and activated later by calling kernfs_activate() to allow creation of multiple nodes to succeed or fail as a unit. This is an one-way one-time-only transition. This patch introduces kernfs_show() which can toggle visibility dynamically. As the currently proposed use - toggling the cgroup pressure files - only requires operating on leaf nodes, for the sake of simplicity, restrict it as such for now. Hiding uses the same mechanism as deactivation and likewise guarantees that there are no in-flight operations on completion. KERNFS_ACTIVATED and KERNFS_HIDDEN are used to manage the interactions between activations and show/hide operations. A node is visible iff both activated & !hidden. Cc: Chengming Zhou <zhouchengming@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20220828050440.734579-9-tj@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff c2549174 Sat Aug 27 23:04:37 MDT 2022 Tejun Heo <tj@kernel.org> kernfs: Add KERNFS_REMOVING flags KERNFS_ACTIVATED tracks whether a given node has ever been activated. As a node was only deactivated on removal, this was used for 1. Drain optimization (removed by the previous patch). 2. To hide !activated nodes 3. To avoid double activations 4. Reject adding children to a node being removed 5. Skip activaing a node which is being removed. We want to decouple deactivation from removal so that nodes can be deactivated and hidden dynamically, which makes KERNFS_ACTIVATED useless for all of the above purposes. #1 is already gone. #2 and #3 can instead test whether the node is currently active. A new flag KERNFS_REMOVING is added to explicitly mark nodes which are being removed for #4 and #5. While this leaves KERNFS_ACTIVATED with no users, leave it be as it will be used in a following patch. Cc: Chengming Zhou <zhouchengming@bytedance.com> Tested-by: Chengming Zhou <zhouchengming@bytedance.com> Reviewed-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20220828050440.734579-7-tj@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff eaf501e0 Sun Sep 12 23:41:11 MDT 2021 Christoph Hellwig <hch@lst.de> kernfs: remove the unused lockdep_key field in struct kernfs_ops Not actually used anywhere. Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210913054121.616001-4-hch@lst.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff 29356624 Sun Sep 12 23:41:10 MDT 2021 Christoph Hellwig <hch@lst.de> kernfs: remove kernfs_create_file and kernfs_create_file_ns All callers actually use __kernfs_create_file. Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210913054121.616001-3-hch@lst.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff 23bf1b6b Thu Nov 01 17:07:26 MDT 2018 David Howells <dhowells@redhat.com> kernfs, sysfs, cgroup, intel_rdt: Support fs_context Make kernfs support superblock creation/mount/remount with fs_context. This requires that sysfs, cgroup and intel_rdt, which are built on kernfs, be made to support fs_context also. Notes: (1) A kernfs_fs_context struct is created to wrap fs_context and the kernfs mount parameters are moved in here (or are in fs_context). (2) kernfs_mount{,_ns}() are made into kernfs_get_tree(). The extra namespace tag parameter is passed in the context if desired (3) kernfs_free_fs_context() is provided as a destructor for the kernfs_fs_context struct, but for the moment it does nothing except get called in the right places. (4) sysfs doesn't wrap kernfs_fs_context since it has no parameters to pass, but possibly this should be done anyway in case someone wants to add a parameter in future. (5) A cgroup_fs_context struct is created to wrap kernfs_fs_context and the cgroup v1 and v2 mount parameters are all moved there. (6) cgroup1 parameter parsing error messages are now handled by invalf(), which allows userspace to collect them directly. (7) cgroup1 parameter cleanup is now done in the context destructor rather than in the mount/get_tree and remount functions. Weirdies: (*) cgroup_do_get_tree() calls cset_cgroup_from_root() with locks held, but then uses the resulting pointer after dropping the locks. I'm told this is okay and needs commenting. (*) The cgroup refcount web. This really needs documenting. (*) cgroup2 only has one root? Add a suggestion from Thomas Gleixner in which the RDT enablement code is placed into its own function. [folded a leak fix from Andrey Vagin] Signed-off-by: David Howells <dhowells@redhat.com> cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> cc: Tejun Heo <tj@kernel.org> cc: Li Zefan <lizefan@huawei.com> cc: Johannes Weiner <hannes@cmpxchg.org> cc: cgroups@vger.kernel.org cc: fenghua.yu@intel.com Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> diff bb09c863 Wed Aug 10 09:23:44 MDT 2016 Tejun Heo <tj@kernel.org> kernfs: remove kernfs_path_len() It doesn't have any in-kernel user and the same result can be obtained from kernfs_path(@kn, NULL, 0). Remove it. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Serge Hallyn <serge.hallyn@ubuntu.com> diff 3abb1d90 Wed Aug 10 09:23:44 MDT 2016 Tejun Heo <tj@kernel.org> kernfs: make kernfs_path*() behave in the style of strlcpy() kernfs_path*() functions always return the length of the full path but the path content is undefined if the length is larger than the provided buffer. This makes its behavior different from strlcpy() and requires error handling in all its users even when they don't care about truncation. In addition, the implementation can actully be simplified by making it behave properly in strlcpy() style. * Update kernfs_path_from_node_locked() to always fill up the buffer with path. If the buffer is not large enough, the output is truncated and terminated. * kernfs_path() no longer needs error handling. Make it a simple inline wrapper around kernfs_path_from_node(). * sysfs_warn_dup()'s use of kernfs_path() doesn't need error handling. Updated accordingly. * cgroup_path()'s use of kernfs_path() updated to retain the old behavior. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com> diff 0e0b2afd Wed Aug 10 09:23:43 MDT 2016 Tejun Heo <tj@kernel.org> kernfs: add dummy implementation of kernfs_path_from_node() The dummy version of kernfs_path_from_node() was missing. This currently doesn't break anything. Let's add it for consistency and to ease adding wrappers around it. v2: Removed stray ';' which was causing build failures. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> diff 2b75869b Sun Oct 12 23:41:28 MDT 2014 NeilBrown <neilb@suse.de> sysfs/kernfs: allow attributes to request write buffer be pre-allocated. md/raid allows metadata management to be performed in user-space. A various times, particularly on device failure, the metadata needs to be updated before further writes can be permitted. This means that the user-space program which updates metadata much not block on writeout, and so must not allocate memory. mlockall(MCL_CURRENT|MCL_FUTURE) and pre-allocation can avoid all memory allocation issues for user-memory, but that does not help kernel memory. Several kernel objects can be pre-allocated. e.g. files opened before any writes to the array are permitted. However some kernel allocation happens in places that cannot be pre-allocated. In particular, writes to sysfs files (to tell md that it can now allow writes to the array) allocate a buffer using GFP_KERNEL. This patch allows attributes to be marked as "PREALLOC". In that case the maximal buffer is allocated when the file is opened, and then used on each write instead of allocating a new buffer. As the same buffer is now shared for all writes on the same file description, the mutex is extended to cover full use of the buffer including the copy_from_user(). The new __ATTR_PREALLOC() 'or's a new flag in to the 'mode', which is inspected by sysfs_add_file_mode_ns() to determine if the file should be marked as requiring prealloc. Despite the comment, we *do* use ->seq_show together with ->prealloc in this patch. The next patch fixes that. Signed-off-by: NeilBrown <neilb@suse.de> Reviewed-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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