From: Tejun Heo <tj@kernel.org>
To: gregkh@linuxfoundation.org
Cc: kay@vrfy.org, linux-kernel@vger.kernel.org,
ebiederm@xmission.com, bhelgaas@google.com,
linux-fsdevel@vger.kernel.org,
Christoph Hellwig <hch@infradead.org>
Subject: [PATCH REPOST 37/41] sysfs, kernfs: prepare mount path for kernfs
Date: Sun, 24 Nov 2013 09:57:54 -0500 [thread overview]
Message-ID: <20131124145754.GC17243@htj.dyndns.org> (raw)
In-Reply-To: <1385245346-856-38-git-send-email-tj@kernel.org>
We're in the process of separating out core sysfs functionality into
kernfs which will deal with sysfs_dirents directly. This patch
rearranges mount path so that the kernfs and sysfs parts are separate.
* As sysfs_super_info won't be visible outside kernfs proper,
kernfs_super_ns() is added to allow kernfs users to access a
super_block's namespace tag.
* Generic mount operation is separated out into kernfs_mount_ns().
sysfs_mount() now just performs sysfs-specific permission check,
acquires namespace tag, and invokes kernfs_mount_ns().
* Generic superblock release is separated out into kernfs_kill_sb()
which can be used directly as file_system_type->kill_sb(). As sysfs
needs to put the namespace tag, sysfs_kill_sb() wraps
kernfs_kill_sb() with ns tag put.
* sysfs_dir_cachep init and sysfs_inode_init() are separated out into
kernfs_init(). kernfs_init() uses only small amount of memory and
trying to handle and propagate kernfs_init() failure doesn't make
much sense. Use SLAB_PANIC for sysfs_dir_cachep and make
sysfs_inode_init() panic on failure.
After this change, kernfs_init() should be called before
sysfs_init(), fs/namespace.c::mnt_init() modified accordingly.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: linux-fsdevel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
---
Reposting w/ linux-fsdevel and hch cc'd. Updated description
slightly. No content change. git branch updated accordingly.
Thanks.
fs/kernfs/inode.c | 5 ++-
fs/kernfs/kernfs-internal.h | 2 +-
fs/namespace.c | 2 +
fs/sysfs/mount.c | 104 ++++++++++++++++++++++++++++++--------------
include/linux/kernfs.h | 28 ++++++++++++
5 files changed, 106 insertions(+), 35 deletions(-)
diff --git a/fs/kernfs/inode.c b/fs/kernfs/inode.c
index 9d4fab4..b4cae6f 100644
--- a/fs/kernfs/inode.c
+++ b/fs/kernfs/inode.c
@@ -37,9 +37,10 @@ static const struct inode_operations sysfs_inode_operations = {
.setxattr = sysfs_setxattr,
};
-int __init sysfs_inode_init(void)
+void __init sysfs_inode_init(void)
{
- return bdi_init(&sysfs_backing_dev_info);
+ if (bdi_init(&sysfs_backing_dev_info))
+ panic("failed to init sysfs_backing_dev_info");
}
static struct sysfs_inode_attrs *sysfs_init_inode_attrs(struct sysfs_dirent *sd)
diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h
index 466943d..0d94988 100644
--- a/fs/kernfs/kernfs-internal.h
+++ b/fs/kernfs/kernfs-internal.h
@@ -144,7 +144,7 @@ int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat);
int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags);
-int sysfs_inode_init(void);
+void sysfs_inode_init(void);
/*
* dir.c
diff --git a/fs/namespace.c b/fs/namespace.c
index ac2ce8a..a511ea0 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -2790,6 +2790,8 @@ void __init mnt_init(void)
for (u = 0; u < HASH_SIZE; u++)
INIT_LIST_HEAD(&mountpoint_hashtable[u]);
+ kernfs_init();
+
err = sysfs_init();
if (err)
printk(KERN_WARNING "%s: sysfs_init error: %d\n",
diff --git a/fs/sysfs/mount.c b/fs/sysfs/mount.c
index f143b20..5384732 100644
--- a/fs/sysfs/mount.c
+++ b/fs/sysfs/mount.c
@@ -86,18 +86,24 @@ static int sysfs_set_super(struct super_block *sb, void *data)
return error;
}
-static void free_sysfs_super_info(struct sysfs_super_info *info)
+/**
+ * kernfs_super_ns - determine the namespace tag of a kernfs super_block
+ * @sb: super_block of interest
+ *
+ * Return the namespace tag associated with kernfs super_block @sb.
+ */
+const void *kernfs_super_ns(struct super_block *sb)
{
- kobj_ns_drop(KOBJ_NS_TYPE_NET, (void *)info->ns);
- kfree(info);
+ struct sysfs_super_info *info = sysfs_info(sb);
+
+ return info->ns;
}
static struct dentry *sysfs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
- struct sysfs_super_info *info;
- struct super_block *sb;
- int error;
+ struct dentry *root;
+ void *ns;
if (!(flags & MS_KERNMOUNT)) {
if (!capable(CAP_SYS_ADMIN) && !fs_fully_visible(fs_type))
@@ -107,16 +113,44 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type,
return ERR_PTR(-EPERM);
}
+ ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
+ root = kernfs_mount_ns(fs_type, flags, sysfs_root, ns);
+ if (IS_ERR(root))
+ kobj_ns_drop(KOBJ_NS_TYPE_NET, ns);
+ return root;
+}
+
+/**
+ * kernfs_mount_ns - kernfs mount helper
+ * @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
+ * @ns: optional namespace tag of the mount
+ *
+ * This is to be called from each kernfs user's file_system_type->mount()
+ * implementation, which should pass through the specified @fs_type and
+ * @flags, and specify the hierarchy and namespace tag to mount via @root
+ * and @ns, respectively.
+ *
+ * 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, const void *ns)
+{
+ struct super_block *sb;
+ struct sysfs_super_info *info;
+ int error;
+
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return ERR_PTR(-ENOMEM);
- info->root = sysfs_root;
- info->ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
+ info->root = root;
+ info->ns = ns;
sb = sget(fs_type, sysfs_test_super, sysfs_set_super, flags, info);
if (IS_ERR(sb) || sb->s_fs_info != info)
- free_sysfs_super_info(info);
+ kfree(info);
if (IS_ERR(sb))
return ERR_CAST(sb);
if (!sb->s_root) {
@@ -133,6 +167,20 @@ static struct dentry *sysfs_mount(struct file_system_type *fs_type,
static void sysfs_kill_sb(struct super_block *sb)
{
+ kernfs_kill_sb(sb);
+ kobj_ns_drop(KOBJ_NS_TYPE_NET, (void *)kernfs_super_ns(sb));
+}
+
+/**
+ * kernfs_kill_sb - kill_sb for kernfs
+ * @sb: super_block being killed
+ *
+ * This can be used directly for file_system_type->kill_sb(). If a kernfs
+ * user needs extra cleanup, it can implement its own kill_sb() and call
+ * this function at the end.
+ */
+void kernfs_kill_sb(struct super_block *sb)
+{
struct sysfs_super_info *info = sysfs_info(sb);
struct sysfs_dirent *root_sd = sb->s_root->d_fsdata;
@@ -141,7 +189,7 @@ static void sysfs_kill_sb(struct super_block *sb)
* so we can't find it, before freeing sysfs_super_info.
*/
kill_anon_super(sb);
- free_sysfs_super_info(info);
+ kfree(info);
kernfs_put(root_sd);
}
@@ -152,37 +200,29 @@ static struct file_system_type sysfs_fs_type = {
.fs_flags = FS_USERNS_MOUNT,
};
-int __init sysfs_init(void)
+void __init kernfs_init(void)
{
- int err;
-
sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
sizeof(struct sysfs_dirent),
- 0, 0, NULL);
- if (!sysfs_dir_cachep)
- return -ENOMEM;
+ 0, SLAB_PANIC, NULL);
+ sysfs_inode_init();
+}
- err = sysfs_inode_init();
- if (err)
- goto out_err;
+int __init sysfs_init(void)
+{
+ int err;
sysfs_root = kernfs_create_root(NULL);
- if (IS_ERR(sysfs_root)) {
- err = PTR_ERR(sysfs_root);
- goto out_err;
- }
+ if (IS_ERR(sysfs_root))
+ return PTR_ERR(sysfs_root);
+
sysfs_root_sd = sysfs_root->sd;
err = register_filesystem(&sysfs_fs_type);
- if (err)
- goto out_destroy_root;
+ if (err) {
+ kernfs_destroy_root(sysfs_root);
+ return err;
+ }
return 0;
-
-out_destroy_root:
- kernfs_destroy_root(sysfs_root);
-out_err:
- kmem_cache_destroy(sysfs_dir_cachep);
- sysfs_dir_cachep = NULL;
- return err;
}
diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h
index fad8b98..75fcbe5 100644
--- a/include/linux/kernfs.h
+++ b/include/linux/kernfs.h
@@ -18,6 +18,8 @@ struct file;
struct iattr;
struct seq_file;
struct vm_area_struct;
+struct super_block;
+struct file_system_type;
struct sysfs_dirent;
@@ -109,6 +111,13 @@ void kernfs_enable_ns(struct sysfs_dirent *sd);
int kernfs_setattr(struct sysfs_dirent *sd, const struct iattr *iattr);
void kernfs_notify(struct sysfs_dirent *sd);
+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, const void *ns);
+void kernfs_kill_sb(struct super_block *sb);
+
+void kernfs_init(void);
+
#else /* CONFIG_SYSFS */
static inline struct sysfs_dirent *
@@ -160,6 +169,18 @@ static inline int kernfs_setattr(struct sysfs_dirent *sd,
static inline void kernfs_notify(struct sysfs_dirent *sd) { }
+static inline const void *kernfs_super_ns(struct super_block *sb)
+{ return NULL; }
+
+static inline struct dentry *
+kernfs_mount_ns(struct file_system_type *fs_type, int flags,
+ struct kernfs_root *root, const void *ns)
+{ return ERR_PTR(-ENOSYS); }
+
+static inline void kernfs_kill_sb(struct super_block *sb) { }
+
+static inline void kernfs_init(void) { }
+
#endif /* CONFIG_SYSFS */
static inline struct sysfs_dirent *
@@ -201,4 +222,11 @@ static inline int kernfs_remove_by_name(struct sysfs_dirent *parent,
return kernfs_remove_by_name_ns(parent, name, NULL);
}
+static inline struct dentry *
+kernfs_mount(struct file_system_type *fs_type, int flags,
+ struct kernfs_root *root)
+{
+ return kernfs_mount_ns(fs_type, flags, root, NULL);
+}
+
#endif /* __LINUX_KERNFS_H */
--
1.8.4.2
next prev parent reply other threads:[~2013-11-24 14:58 UTC|newest]
Thread overview: 92+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-23 22:21 [PATCHSET driver-core-next] sysfs: separate out kernfs, take #3 Tejun Heo
2013-11-23 22:21 ` [PATCH 01/41] sysfs: drop kobj_ns_type handling, take #2 Tejun Heo
2013-11-23 23:05 ` [PATCH v2 " Tejun Heo
2013-11-23 22:21 ` [PATCH 02/41] sysfs: make __sysfs_add_one() fail if the parent isn't a directory Tejun Heo
2013-11-23 22:21 ` [PATCH 03/41] sysfs, kernfs: add skeletons for kernfs Tejun Heo
2013-11-24 14:54 ` [PATCH REPOST " Tejun Heo
2013-11-23 22:21 ` [PATCH 04/41] sysfs, kernfs: introduce kernfs_remove[_by_name[_ns]]() Tejun Heo
2013-11-23 22:21 ` [PATCH 05/41] sysfs, kernfs: introduce kernfs_create_link() Tejun Heo
2013-11-23 22:21 ` [PATCH 06/41] sysfs, kernfs: introduce kernfs_rename[_ns]() Tejun Heo
2013-11-23 22:21 ` [PATCH 07/41] sysfs, kernfs: introduce kernfs_setattr() Tejun Heo
2013-11-23 22:21 ` [PATCH 08/41] sysfs, kernfs: replace sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with ->priv Tejun Heo
2013-11-23 22:21 ` [PATCH 09/41] sysfs, kernfs: introduce kernfs_create_dir[_ns]() Tejun Heo
2013-11-23 23:07 ` [PATCH v4 " Tejun Heo
2013-11-28 6:05 ` Greg KH
2013-11-28 19:54 ` [PATCHSET PARTIAL REPOST driver-core-next] sysfs: separate out kernfs, take #3 Tejun Heo
2013-11-28 19:54 ` [PATCH 01/34] sysfs, kernfs: replace sysfs_dirent->s_dir.kobj and ->s_attr.[bin_]attr with ->priv Tejun Heo
2013-11-28 19:54 ` [PATCH 02/34] sysfs, kernfs: introduce kernfs_create_dir[_ns]() Tejun Heo
2013-11-28 19:54 ` [PATCH 03/34] sysfs, kernfs: prepare read path for kernfs Tejun Heo
2013-11-28 19:54 ` [PATCH 04/34] sysfs, kernfs: prepare write " Tejun Heo
2013-11-28 19:54 ` [PATCH 05/34] sysfs, kernfs: prepare mmap " Tejun Heo
2013-11-28 19:54 ` [PATCH 06/34] sysfs, kernfs: prepare open, release, poll paths " Tejun Heo
2013-11-28 19:54 ` [PATCH 07/34] sysfs, kernfs: move sysfs_open_file to include/linux/kernfs.h Tejun Heo
2013-11-28 19:54 ` [PATCH 08/34] sysfs, kernfs: introduce kernfs_ops Tejun Heo
2013-11-28 19:54 ` [PATCH 09/34] sysfs, kernfs: add sysfs_dirent->s_attr.size Tejun Heo
2013-11-28 19:54 ` [PATCH 10/34] sysfs, kernfs: remove SYSFS_KOBJ_BIN_ATTR Tejun Heo
2013-11-28 19:54 ` [PATCH 11/34] sysfs, kernfs: introduce kernfs_create_file[_ns]() Tejun Heo
2013-11-28 19:54 ` [PATCH 12/34] sysfs, kernfs: remove sysfs_add_one() Tejun Heo
2013-11-28 19:54 ` [PATCH 13/34] sysfs, kernfs: add kernfs_ops->seq_{start|next|stop}() Tejun Heo
2013-11-28 19:54 ` [PATCH 14/34] sysfs, kernfs: introduce kernfs_notify() Tejun Heo
2013-11-28 19:54 ` [PATCH 15/34] sysfs, kernfs: reorganize SYSFS_* constants Tejun Heo
2013-11-28 19:54 ` [PATCH 16/34] sysfs, kernfs: revamp sysfs_dirent active_ref lockdep annotation Tejun Heo
2013-11-28 19:54 ` [PATCH 17/34] sysfs, kernfs: introduce kernfs[_find_and]_get() and kernfs_put() Tejun Heo
2013-11-28 19:54 ` [PATCH 18/34] sysfs, kernfs: move internal decls to fs/kernfs/kernfs-internal.h Tejun Heo
2013-11-28 19:54 ` [PATCH 19/34] sysfs, kernfs: move inode code to fs/kernfs/inode.c Tejun Heo
2013-11-28 19:54 ` [PATCH 20/34] sysfs, kernfs: move dir core code to fs/kernfs/dir.c Tejun Heo
2013-11-28 19:54 ` [PATCH 21/34] sysfs, kernfs: move file core code to fs/kernfs/file.c Tejun Heo
2013-11-28 19:54 ` [PATCH 22/34] sysfs, kernfs: move symlink core code to fs/kernfs/symlink.c Tejun Heo
2013-11-28 19:54 ` [PATCH 23/34] sysfs, kernfs: drop unused params from sysfs_fill_super() Tejun Heo
2013-11-28 19:54 ` [PATCH 24/34] sysfs, kernfs: make sysfs_super_info->ns const Tejun Heo
2013-11-28 19:54 ` [PATCH 25/34] sysfs, kernfs: no need to kern_mount() sysfs from sysfs_init() Tejun Heo
2013-11-28 19:54 ` [PATCH 26/34] sysfs, kernfs: introduce sysfs_root_sd Tejun Heo
2013-11-28 19:54 ` [PATCH 27/34] sysfs, kernfs: implement kernfs_create/destroy_root() Tejun Heo
2013-11-28 19:54 ` [PATCH 28/34] sysfs, kernfs: make inode number ida per kernfs_root Tejun Heo
2013-11-28 19:54 ` [PATCH 29/34] sysfs, kernfs: make super_blocks bind to different kernfs_roots Tejun Heo
2013-11-28 19:54 ` [PATCH 30/34] sysfs, kernfs: prepare mount path for kernfs Tejun Heo
2013-11-28 19:54 ` [PATCH 31/34] sysfs, kernfs: move mount core code to fs/kernfs/mount.c Tejun Heo
2013-11-28 19:54 ` [PATCH 32/34] sysfs, kernfs: make sysfs_dirent definition public Tejun Heo
2013-11-29 22:18 ` Tejun Heo
2013-11-29 22:19 ` Tejun Heo
2013-11-28 19:54 ` [PATCH 33/34] sysfs, kernfs: implement kernfs_ns_enabled() Tejun Heo
2013-11-29 22:19 ` [PATCH v2 " Tejun Heo
2013-11-28 19:54 ` [PATCH 34/34] sysfs, kernfs: remove cross inclusions of internal headers Tejun Heo
2013-11-29 22:21 ` [PATCHSET PARTIAL REPOST driver-core-next] sysfs: separate out kernfs, take #3 Tejun Heo
2013-11-30 2:55 ` Greg KH
2013-11-30 13:05 ` Tejun Heo
2013-11-23 22:21 ` [PATCH 10/41] sysfs, kernfs: prepare read path for kernfs Tejun Heo
2013-11-23 22:21 ` [PATCH 11/41] sysfs, kernfs: prepare write " Tejun Heo
2013-11-23 22:21 ` [PATCH 12/41] sysfs, kernfs: prepare mmap " Tejun Heo
2013-11-23 22:21 ` [PATCH 13/41] sysfs, kernfs: prepare open, release, poll paths " Tejun Heo
2013-11-23 22:21 ` [PATCH 14/41] sysfs, kernfs: move sysfs_open_file to include/linux/kernfs.h Tejun Heo
2013-11-23 22:22 ` [PATCH 15/41] sysfs, kernfs: introduce kernfs_ops Tejun Heo
2013-11-23 22:22 ` [PATCH 16/41] sysfs, kernfs: add sysfs_dirent->s_attr.size Tejun Heo
2013-11-23 22:22 ` [PATCH 17/41] sysfs, kernfs: remove SYSFS_KOBJ_BIN_ATTR Tejun Heo
2013-11-23 22:22 ` [PATCH 18/41] sysfs, kernfs: introduce kernfs_create_file[_ns]() Tejun Heo
2013-11-23 22:22 ` [PATCH 19/41] sysfs, kernfs: remove sysfs_add_one() Tejun Heo
2013-11-23 22:22 ` [PATCH 20/41] sysfs, kernfs: add kernfs_ops->seq_{start|next|stop}() Tejun Heo
2013-11-23 22:22 ` [PATCH 21/41] sysfs, kernfs: introduce kernfs_notify() Tejun Heo
2013-11-23 22:22 ` [PATCH 22/41] sysfs, kernfs: reorganize SYSFS_* constants Tejun Heo
2013-11-23 22:22 ` [PATCH 23/41] sysfs, kernfs: revamp sysfs_dirent active_ref lockdep annotation Tejun Heo
2013-11-23 22:22 ` [PATCH 24/41] sysfs, kernfs: introduce kernfs[_find_and]_get() and kernfs_put() Tejun Heo
2013-11-23 22:22 ` [PATCH 25/41] sysfs, kernfs: move internal decls to fs/kernfs/kernfs-internal.h Tejun Heo
2013-11-23 22:22 ` [PATCH 26/41] sysfs, kernfs: move inode code to fs/kernfs/inode.c Tejun Heo
2013-11-23 22:22 ` [PATCH 27/41] sysfs, kernfs: move dir core code to fs/kernfs/dir.c Tejun Heo
2013-11-23 22:22 ` [PATCH 28/41] sysfs, kernfs: move file core code to fs/kernfs/file.c Tejun Heo
2013-11-23 22:22 ` [PATCH 29/41] sysfs, kernfs: move symlink core code to fs/kernfs/symlink.c Tejun Heo
2013-11-23 22:22 ` [PATCH 30/41] sysfs, kernfs: drop unused params from sysfs_fill_super() Tejun Heo
2013-11-23 22:22 ` [PATCH 31/41] sysfs, kernfs: make sysfs_super_info->ns const Tejun Heo
2013-11-23 22:22 ` [PATCH 32/41] sysfs, kernfs: no need to kern_mount() sysfs from sysfs_init() Tejun Heo
2013-11-23 22:22 ` [PATCH 33/41] sysfs, kernfs: introduce sysfs_root_sd Tejun Heo
2013-11-23 22:22 ` [PATCH 34/41] sysfs, kernfs: implement kernfs_create/destroy_root() Tejun Heo
2013-11-23 22:22 ` [PATCH 35/41] sysfs, kernfs: make inode number ida per kernfs_root Tejun Heo
2013-11-23 22:22 ` [PATCH 36/41] sysfs, kernfs: make super_blocks bind to different kernfs_roots Tejun Heo
2013-11-23 22:22 ` [PATCH 37/41] sysfs, kernfs: prepare mount path for kernfs Tejun Heo
2013-11-24 14:57 ` Tejun Heo [this message]
2013-11-23 22:22 ` [PATCH 38/41] sysfs, kernfs: move mount core code to fs/kernfs/mount.c Tejun Heo
2013-11-23 22:22 ` [PATCH 39/41] sysfs, kernfs: make sysfs_dirent definition public Tejun Heo
2013-11-23 22:22 ` [PATCH 40/41] sysfs, kernfs: implement kernfs_ns_enabled() Tejun Heo
2013-11-23 22:22 ` [PATCH 41/41] sysfs, kernfs: remove cross inclusions of internal headers Tejun Heo
2013-11-23 22:48 ` [PATCHSET driver-core-next] sysfs: separate out kernfs, take #3 Tejun Heo
2013-11-23 23:09 ` Tejun Heo
2013-11-24 9:16 ` Christoph Hellwig
2013-11-24 14:28 ` Tejun Heo
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