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Diffstat (limited to 'fs/debugfs/inode.c')
-rw-r--r--fs/debugfs/inode.c291
1 files changed, 168 insertions, 123 deletions
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 05f2960ed7c3..45b18a5e225c 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -34,93 +34,16 @@ static struct vfsmount *debugfs_mount;
static int debugfs_mount_count;
static bool debugfs_registered;
-static struct inode *debugfs_get_inode(struct super_block *sb, umode_t mode, dev_t dev,
- void *data, const struct file_operations *fops)
-
+static struct inode *debugfs_get_inode(struct super_block *sb)
{
struct inode *inode = new_inode(sb);
-
if (inode) {
inode->i_ino = get_next_ino();
- inode->i_mode = mode;
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
- switch (mode & S_IFMT) {
- default:
- init_special_inode(inode, mode, dev);
- break;
- case S_IFREG:
- inode->i_fop = fops ? fops : &debugfs_file_operations;
- inode->i_private = data;
- break;
- case S_IFLNK:
- inode->i_op = &debugfs_link_operations;
- inode->i_private = data;
- break;
- case S_IFDIR:
- inode->i_op = &simple_dir_inode_operations;
- inode->i_fop = &simple_dir_operations;
-
- /* directory inodes start off with i_nlink == 2
- * (for "." entry) */
- inc_nlink(inode);
- break;
- }
}
return inode;
}
-/* SMP-safe */
-static int debugfs_mknod(struct inode *dir, struct dentry *dentry,
- umode_t mode, dev_t dev, void *data,
- const struct file_operations *fops)
-{
- struct inode *inode;
- int error = -EPERM;
-
- if (dentry->d_inode)
- return -EEXIST;
-
- inode = debugfs_get_inode(dir->i_sb, mode, dev, data, fops);
- if (inode) {
- d_instantiate(dentry, inode);
- dget(dentry);
- error = 0;
- }
- return error;
-}
-
-static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
-{
- int res;
-
- mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
- res = debugfs_mknod(dir, dentry, mode, 0, NULL, NULL);
- if (!res) {
- inc_nlink(dir);
- fsnotify_mkdir(dir, dentry);
- }
- return res;
-}
-
-static int debugfs_link(struct inode *dir, struct dentry *dentry, umode_t mode,
- void *data)
-{
- mode = (mode & S_IALLUGO) | S_IFLNK;
- return debugfs_mknod(dir, dentry, mode, 0, data, NULL);
-}
-
-static int debugfs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
- void *data, const struct file_operations *fops)
-{
- int res;
-
- mode = (mode & S_IALLUGO) | S_IFREG;
- res = debugfs_mknod(dir, dentry, mode, 0, data, fops);
- if (!res)
- fsnotify_create(dir, dentry);
- return res;
-}
-
static inline int debugfs_positive(struct dentry *dentry)
{
return dentry->d_inode && !d_unhashed(dentry);
@@ -252,6 +175,18 @@ static const struct super_operations debugfs_super_operations = {
.show_options = debugfs_show_options,
};
+static struct vfsmount *debugfs_automount(struct path *path)
+{
+ struct vfsmount *(*f)(void *);
+ f = (struct vfsmount *(*)(void *))path->dentry->d_fsdata;
+ return f(path->dentry->d_inode->i_private);
+}
+
+static const struct dentry_operations debugfs_dops = {
+ .d_delete = always_delete_dentry,
+ .d_automount = debugfs_automount,
+};
+
static int debug_fill_super(struct super_block *sb, void *data, int silent)
{
static struct tree_descr debug_files[] = {{""}};
@@ -276,6 +211,7 @@ static int debug_fill_super(struct super_block *sb, void *data, int silent)
goto fail;
sb->s_op = &debugfs_super_operations;
+ sb->s_d_op = &debugfs_dops;
debugfs_apply_options(sb);
@@ -302,11 +238,9 @@ static struct file_system_type debug_fs_type = {
};
MODULE_ALIAS_FS("debugfs");
-static struct dentry *__create_file(const char *name, umode_t mode,
- struct dentry *parent, void *data,
- const struct file_operations *fops)
+static struct dentry *start_creating(const char *name, struct dentry *parent)
{
- struct dentry *dentry = NULL;
+ struct dentry *dentry;
int error;
pr_debug("debugfs: creating file '%s'\n",name);
@@ -314,7 +248,7 @@ static struct dentry *__create_file(const char *name, umode_t mode,
error = simple_pin_fs(&debug_fs_type, &debugfs_mount,
&debugfs_mount_count);
if (error)
- goto exit;
+ return ERR_PTR(error);
/* If the parent is not specified, we create it in the root.
* We need the root dentry to do this, which is in the super
@@ -326,31 +260,26 @@ static struct dentry *__create_file(const char *name, umode_t mode,
mutex_lock(&parent->d_inode->i_mutex);
dentry = lookup_one_len(name, parent, strlen(name));
- if (!IS_ERR(dentry)) {
- switch (mode & S_IFMT) {
- case S_IFDIR:
- error = debugfs_mkdir(parent->d_inode, dentry, mode);
-
- break;
- case S_IFLNK:
- error = debugfs_link(parent->d_inode, dentry, mode,
- data);
- break;
- default:
- error = debugfs_create(parent->d_inode, dentry, mode,
- data, fops);
- break;
- }
+ if (!IS_ERR(dentry) && dentry->d_inode) {
dput(dentry);
- } else
- error = PTR_ERR(dentry);
- mutex_unlock(&parent->d_inode->i_mutex);
-
- if (error) {
- dentry = NULL;
- simple_release_fs(&debugfs_mount, &debugfs_mount_count);
+ dentry = ERR_PTR(-EEXIST);
}
-exit:
+ if (IS_ERR(dentry))
+ mutex_unlock(&parent->d_inode->i_mutex);
+ return dentry;
+}
+
+static struct dentry *failed_creating(struct dentry *dentry)
+{
+ mutex_unlock(&dentry->d_parent->d_inode->i_mutex);
+ dput(dentry);
+ simple_release_fs(&debugfs_mount, &debugfs_mount_count);
+ return NULL;
+}
+
+static struct dentry *end_creating(struct dentry *dentry)
+{
+ mutex_unlock(&dentry->d_parent->d_inode->i_mutex);
return dentry;
}
@@ -384,19 +313,71 @@ struct dentry *debugfs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *fops)
{
- switch (mode & S_IFMT) {
- case S_IFREG:
- case 0:
- break;
- default:
- BUG();
- }
+ struct dentry *dentry;
+ struct inode *inode;
+
+ if (!(mode & S_IFMT))
+ mode |= S_IFREG;
+ BUG_ON(!S_ISREG(mode));
+ dentry = start_creating(name, parent);
+
+ if (IS_ERR(dentry))
+ return NULL;
- return __create_file(name, mode, parent, data, fops);
+ inode = debugfs_get_inode(dentry->d_sb);
+ if (unlikely(!inode))
+ return failed_creating(dentry);
+
+ inode->i_mode = mode;
+ inode->i_fop = fops ? fops : &debugfs_file_operations;
+ inode->i_private = data;
+ d_instantiate(dentry, inode);
+ fsnotify_create(dentry->d_parent->d_inode, dentry);
+ return end_creating(dentry);
}
EXPORT_SYMBOL_GPL(debugfs_create_file);
/**
+ * debugfs_create_file_size - create a file in the debugfs filesystem
+ * @name: a pointer to a string containing the name of the file to create.
+ * @mode: the permission that the file should have.
+ * @parent: a pointer to the parent dentry for this file. This should be a
+ * directory dentry if set. If this parameter is NULL, then the
+ * file will be created in the root of the debugfs filesystem.
+ * @data: a pointer to something that the caller will want to get to later
+ * on. The inode.i_private pointer will point to this value on
+ * the open() call.
+ * @fops: a pointer to a struct file_operations that should be used for
+ * this file.
+ * @file_size: initial file size
+ *
+ * This is the basic "create a file" function for debugfs. It allows for a
+ * wide range of flexibility in creating a file, or a directory (if you want
+ * to create a directory, the debugfs_create_dir() function is
+ * recommended to be used instead.)
+ *
+ * This function will return a pointer to a dentry if it succeeds. This
+ * pointer must be passed to the debugfs_remove() function when the file is
+ * to be removed (no automatic cleanup happens if your module is unloaded,
+ * you are responsible here.) If an error occurs, %NULL will be returned.
+ *
+ * If debugfs is not enabled in the kernel, the value -%ENODEV will be
+ * returned.
+ */
+struct dentry *debugfs_create_file_size(const char *name, umode_t mode,
+ struct dentry *parent, void *data,
+ const struct file_operations *fops,
+ loff_t file_size)
+{
+ struct dentry *de = debugfs_create_file(name, mode, parent, data, fops);
+
+ if (de)
+ de->d_inode->i_size = file_size;
+ return de;
+}
+EXPORT_SYMBOL_GPL(debugfs_create_file_size);
+
+/**
* debugfs_create_dir - create a directory in the debugfs filesystem
* @name: a pointer to a string containing the name of the directory to
* create.
@@ -416,12 +397,65 @@ EXPORT_SYMBOL_GPL(debugfs_create_file);
*/
struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
{
- return __create_file(name, S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
- parent, NULL, NULL);
+ struct dentry *dentry = start_creating(name, parent);
+ struct inode *inode;
+
+ if (IS_ERR(dentry))
+ return NULL;
+
+ inode = debugfs_get_inode(dentry->d_sb);
+ if (unlikely(!inode))
+ return failed_creating(dentry);
+
+ inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
+ inode->i_op = &simple_dir_inode_operations;
+ inode->i_fop = &simple_dir_operations;
+
+ /* directory inodes start off with i_nlink == 2 (for "." entry) */
+ inc_nlink(inode);
+ d_instantiate(dentry, inode);
+ inc_nlink(dentry->d_parent->d_inode);
+ fsnotify_mkdir(dentry->d_parent->d_inode, dentry);
+ return end_creating(dentry);
}
EXPORT_SYMBOL_GPL(debugfs_create_dir);
/**
+ * debugfs_create_automount - create automount point in the debugfs filesystem
+ * @name: a pointer to a string containing the name of the file to create.
+ * @parent: a pointer to the parent dentry for this file. This should be a
+ * directory dentry if set. If this parameter is NULL, then the
+ * file will be created in the root of the debugfs filesystem.
+ * @f: function to be called when pathname resolution steps on that one.
+ * @data: opaque argument to pass to f().
+ *
+ * @f should return what ->d_automount() would.
+ */
+struct dentry *debugfs_create_automount(const char *name,
+ struct dentry *parent,
+ struct vfsmount *(*f)(void *),
+ void *data)
+{
+ struct dentry *dentry = start_creating(name, parent);
+ struct inode *inode;
+
+ if (IS_ERR(dentry))
+ return NULL;
+
+ inode = debugfs_get_inode(dentry->d_sb);
+ if (unlikely(!inode))
+ return failed_creating(dentry);
+
+ inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
+ inode->i_flags |= S_AUTOMOUNT;
+ inode->i_private = data;
+ dentry->d_fsdata = (void *)f;
+ d_instantiate(dentry, inode);
+ return end_creating(dentry);
+}
+EXPORT_SYMBOL(debugfs_create_automount);
+
+/**
* debugfs_create_symlink- create a symbolic link in the debugfs filesystem
* @name: a pointer to a string containing the name of the symbolic link to
* create.
@@ -447,17 +481,28 @@ EXPORT_SYMBOL_GPL(debugfs_create_dir);
struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
const char *target)
{
- struct dentry *result;
- char *link;
-
- link = kstrdup(target, GFP_KERNEL);
+ struct dentry *dentry;
+ struct inode *inode;
+ char *link = kstrdup(target, GFP_KERNEL);
if (!link)
return NULL;
- result = __create_file(name, S_IFLNK | S_IRWXUGO, parent, link, NULL);
- if (!result)
+ dentry = start_creating(name, parent);
+ if (IS_ERR(dentry)) {
kfree(link);
- return result;
+ return NULL;
+ }
+
+ inode = debugfs_get_inode(dentry->d_sb);
+ if (unlikely(!inode)) {
+ kfree(link);
+ return failed_creating(dentry);
+ }
+ inode->i_mode = S_IFLNK | S_IRWXUGO;
+ inode->i_op = &debugfs_link_operations;
+ inode->i_private = link;
+ d_instantiate(dentry, inode);
+ return end_creating(dentry);
}
EXPORT_SYMBOL_GPL(debugfs_create_symlink);