From 7d568a8383bbb9c1f5167781075906acb2bb1550 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 9 Apr 2014 11:07:30 -0400 Subject: kernfs: implement kernfs_root->supers list 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 --- fs/kernfs/dir.c | 1 + fs/kernfs/kernfs-internal.h | 5 +++++ fs/kernfs/mount.c | 11 +++++++++++ 3 files changed, 17 insertions(+) (limited to 'fs') diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index 78f3403300af..43aa97988c31 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -711,6 +711,7 @@ struct kernfs_root *kernfs_create_root(struct kernfs_syscall_ops *scops, return ERR_PTR(-ENOMEM); ida_init(&root->ino_ida); + INIT_LIST_HEAD(&root->supers); kn = __kernfs_new_node(root, "", S_IFDIR | S_IRUGO | S_IXUGO, KERNFS_DIR); diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index 8be13b2a079b..dc84a3ef9ca2 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -49,6 +49,8 @@ static inline struct kernfs_root *kernfs_root(struct kernfs_node *kn) * mount.c */ struct kernfs_super_info { + struct super_block *sb; + /* * The root associated with this super_block. Each super_block is * identified by the root and ns it's associated with. @@ -62,6 +64,9 @@ struct kernfs_super_info { * an array and compare kernfs_node tag against every entry. */ const void *ns; + + /* anchored at kernfs_root->supers, protected by kernfs_mutex */ + struct list_head node; }; #define kernfs_info(SB) ((struct kernfs_super_info *)(SB->s_fs_info)) diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 6a5f04ac8704..f25a7c0c3cdc 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -68,6 +68,7 @@ static int kernfs_fill_super(struct super_block *sb) struct inode *inode; struct dentry *root; + info->sb = sb; sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; sb->s_magic = SYSFS_MAGIC; @@ -166,12 +167,18 @@ struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, *new_sb_created = !sb->s_root; if (!sb->s_root) { + struct kernfs_super_info *info = kernfs_info(sb); + error = kernfs_fill_super(sb); if (error) { deactivate_locked_super(sb); return ERR_PTR(error); } sb->s_flags |= MS_ACTIVE; + + mutex_lock(&kernfs_mutex); + list_add(&info->node, &root->supers); + mutex_unlock(&kernfs_mutex); } return dget(sb->s_root); @@ -190,6 +197,10 @@ void kernfs_kill_sb(struct super_block *sb) struct kernfs_super_info *info = kernfs_info(sb); struct kernfs_node *root_kn = sb->s_root->d_fsdata; + mutex_lock(&kernfs_mutex); + list_del(&info->node); + mutex_unlock(&kernfs_mutex); + /* * Remove the superblock from fs_supers/s_instances * so we can't find it, before freeing kernfs_super_info. -- cgit v1.2.3 From d911d98748018f7c8facc035ba39c30f5cce6f9c Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 9 Apr 2014 11:07:31 -0400 Subject: kernfs: make kernfs_notify() trigger inotify events too kernfs_notify() is used to indicate either new data is available or the content of a file has changed. It currently only triggers poll which may not be the most convenient to monitor especially when there are a lot to monitor. Let's hook it up to fsnotify too so that the events can be monitored via inotify too. fsnotify_modify() requires file * but kernfs_notify() doesn't have any specific file associated; however, we can walk all super_blocks associated with a kernfs_root and as kernfs always associate one ino with inode and one dentry with an inode, it's trivial to look up the dentry associated with a given kernfs_node. As any active monitor would pin dentry, just looking up existing dentry is enough. This patch looks up the dentry associated with the specified kernfs_node and generates events equivalent to fsnotify_modify(). Note that as fsnotify doesn't provide fsnotify_modify() equivalent which can be called with dentry, kernfs_notify() directly calls fsnotify_parent() and fsnotify(). It might be better to add a wrapper in fsnotify.h instead. Signed-off-by: Tejun Heo Cc: John McCutchan Cc: Robert Love Cc: Eric Paris Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/file.c | 41 +++++++++++++++++++++++++++++++++++------ 1 file changed, 35 insertions(+), 6 deletions(-) (limited to 'fs') diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index 8034706a7af8..98bacd9ea7fd 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -14,6 +14,7 @@ #include #include #include +#include #include "kernfs-internal.h" @@ -785,20 +786,48 @@ static unsigned int kernfs_fop_poll(struct file *filp, poll_table *wait) */ void kernfs_notify(struct kernfs_node *kn) { + struct kernfs_root *root = kernfs_root(kn); struct kernfs_open_node *on; + struct kernfs_super_info *info; unsigned long flags; + if (WARN_ON(kernfs_type(kn) != KERNFS_FILE)) + return; + + /* kick poll */ spin_lock_irqsave(&kernfs_open_node_lock, flags); - if (!WARN_ON(kernfs_type(kn) != KERNFS_FILE)) { - on = kn->attr.open; - if (on) { - atomic_inc(&on->event); - wake_up_interruptible(&on->poll); - } + on = kn->attr.open; + if (on) { + atomic_inc(&on->event); + wake_up_interruptible(&on->poll); } spin_unlock_irqrestore(&kernfs_open_node_lock, flags); + + /* kick fsnotify */ + mutex_lock(&kernfs_mutex); + + list_for_each_entry(info, &root->supers, node) { + struct inode *inode; + struct dentry *dentry; + + inode = ilookup(info->sb, kn->ino); + if (!inode) + continue; + + dentry = d_find_any_alias(inode); + if (dentry) { + fsnotify_parent(NULL, dentry, FS_MODIFY); + fsnotify(inode, FS_MODIFY, inode, FSNOTIFY_EVENT_INODE, + NULL, 0); + dput(dentry); + } + + iput(inode); + } + + mutex_unlock(&kernfs_mutex); } EXPORT_SYMBOL_GPL(kernfs_notify); -- cgit v1.2.3 From 9f70a40128a4ddceffb6d21dd490f6ab4bc34c97 Mon Sep 17 00:00:00 2001 From: Robert ABEL Date: Mon, 5 May 2014 15:17:20 +0200 Subject: sysfs: fix attribute_group bin file path on removal Cody Schafer already fixed binary file creation for attribute groups, see [1]. This patch makes the appropriate changes for binary file removal of attribute groups. [1]: http://lkml.org/lkml/2014/2/27/832 Signed-off-by: Robert ABEL Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/group.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'fs') diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index aa0406895b53..7d2a860ba788 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -18,7 +18,7 @@ #include "sysfs.h" -static void remove_files(struct kernfs_node *parent, struct kobject *kobj, +static void remove_files(struct kernfs_node *parent, const struct attribute_group *grp) { struct attribute *const *attr; @@ -29,7 +29,7 @@ static void remove_files(struct kernfs_node *parent, struct kobject *kobj, kernfs_remove_by_name(parent, (*attr)->name); if (grp->bin_attrs) for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) - sysfs_remove_bin_file(kobj, *bin_attr); + kernfs_remove_by_name(parent, (*bin_attr)->attr.name); } static int create_files(struct kernfs_node *parent, struct kobject *kobj, @@ -62,7 +62,7 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, break; } if (error) { - remove_files(parent, kobj, grp); + remove_files(parent, grp); goto exit; } } @@ -79,7 +79,7 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj, break; } if (error) - remove_files(parent, kobj, grp); + remove_files(parent, grp); } exit: return error; @@ -224,7 +224,7 @@ void sysfs_remove_group(struct kobject *kobj, kernfs_get(kn); } - remove_files(kn, kobj, grp); + remove_files(kn, grp); if (grp->name) kernfs_remove(kn); -- cgit v1.2.3 From 26fc9cd200ec839e0b3095e05ae018f27314e7aa Mon Sep 17 00:00:00 2001 From: Jianyu Zhan Date: Sat, 26 Apr 2014 15:40:28 +0800 Subject: kernfs: move the last knowledge of sysfs out from kernfs There is still one residue of sysfs remaining: the sb_magic SYSFS_MAGIC. However this should be kernfs user specific, so this patch moves it out. Kerrnfs user should specify their magic number while mouting. Signed-off-by: Jianyu Zhan Acked-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman --- fs/kernfs/mount.c | 11 ++++++----- fs/sysfs/mount.c | 4 +++- include/linux/kernfs.h | 13 ++++++++----- kernel/cgroup.c | 4 +++- 4 files changed, 20 insertions(+), 12 deletions(-) (limited to 'fs') diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index f25a7c0c3cdc..d171b98a6cdd 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -62,7 +62,7 @@ struct kernfs_root *kernfs_root_from_sb(struct super_block *sb) return NULL; } -static int kernfs_fill_super(struct super_block *sb) +static int kernfs_fill_super(struct super_block *sb, unsigned long magic) { struct kernfs_super_info *info = kernfs_info(sb); struct inode *inode; @@ -71,7 +71,7 @@ static int kernfs_fill_super(struct super_block *sb) info->sb = sb; sb->s_blocksize = PAGE_CACHE_SIZE; sb->s_blocksize_bits = PAGE_CACHE_SHIFT; - sb->s_magic = SYSFS_MAGIC; + sb->s_magic = magic; sb->s_op = &kernfs_sops; sb->s_time_gran = 1; @@ -132,6 +132,7 @@ const void *kernfs_super_ns(struct super_block *sb) * @fs_type: file_system_type of the fs being mounted * @flags: mount flags specified for the mount * @root: kernfs_root of the hierarchy being mounted + * @magic: file system specific magic number * @new_sb_created: tell the caller if we allocated a new superblock * @ns: optional namespace tag of the mount * @@ -143,8 +144,8 @@ const void *kernfs_super_ns(struct super_block *sb) * The return value can be passed to the vfs layer verbatim. */ struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, - struct kernfs_root *root, bool *new_sb_created, - const void *ns) + struct kernfs_root *root, unsigned long magic, + bool *new_sb_created, const void *ns) { struct super_block *sb; struct kernfs_super_info *info; @@ -169,7 +170,7 @@ struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, if (!sb->s_root) { struct kernfs_super_info *info = kernfs_info(sb); - error = kernfs_fill_super(sb); + error = kernfs_fill_super(sb, magic); if (error) { deactivate_locked_super(sb); return ERR_PTR(error); diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c index 8794423f7efb..8a49486bf30c 100644 --- a/fs/sysfs/mount.c +++ b/fs/sysfs/mount.c @@ -13,6 +13,7 @@ #define DEBUG #include +#include #include #include #include @@ -38,7 +39,8 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type, } ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET); - root = kernfs_mount_ns(fs_type, flags, sysfs_root, &new_sb, ns); + root = kernfs_mount_ns(fs_type, flags, sysfs_root, + SYSFS_MAGIC, &new_sb, ns); if (IS_ERR(root) || !new_sb) kobj_ns_drop(KOBJ_NS_TYPE_NET, ns); return root; diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index c841688a78a3..17aa1cce6f8e 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -301,8 +301,8 @@ void kernfs_notify(struct kernfs_node *kn); const void *kernfs_super_ns(struct super_block *sb); struct dentry *kernfs_mount_ns(struct file_system_type *fs_type, int flags, - struct kernfs_root *root, bool *new_sb_created, - const void *ns); + struct kernfs_root *root, unsigned long magic, + bool *new_sb_created, const void *ns); void kernfs_kill_sb(struct super_block *sb); void kernfs_init(void); @@ -395,7 +395,8 @@ static inline const void *kernfs_super_ns(struct super_block *sb) static inline struct dentry * kernfs_mount_ns(struct file_system_type *fs_type, int flags, - struct kernfs_root *root, bool *new_sb_created, const void *ns) + struct kernfs_root *root, unsigned long magic, + bool *new_sb_created, const void *ns) { return ERR_PTR(-ENOSYS); } static inline void kernfs_kill_sb(struct super_block *sb) { } @@ -453,9 +454,11 @@ static inline int kernfs_rename(struct kernfs_node *kn, static inline struct dentry * kernfs_mount(struct file_system_type *fs_type, int flags, - struct kernfs_root *root, bool *new_sb_created) + struct kernfs_root *root, unsigned long magic, + bool *new_sb_created) { - return kernfs_mount_ns(fs_type, flags, root, new_sb_created, NULL); + return kernfs_mount_ns(fs_type, flags, root, + magic, new_sb_created, NULL); } #endif /* __LINUX_KERNFS_H */ diff --git a/kernel/cgroup.c b/kernel/cgroup.c index 3f1ca934a237..ceee0c54c6a4 100644 --- a/kernel/cgroup.c +++ b/kernel/cgroup.c @@ -33,6 +33,7 @@ #include #include #include +#include #include #include #include @@ -1604,7 +1605,8 @@ out_unlock: if (ret) return ERR_PTR(ret); - dentry = kernfs_mount(fs_type, flags, root->kf_root, &new_sb); + dentry = kernfs_mount(fs_type, flags, root->kf_root, + CGROUP_SUPER_MAGIC, &new_sb); if (IS_ERR(dentry) || !new_sb) cgroup_put(&root->cgrp); return dentry; -- cgit v1.2.3