Messages in this thread Patch in this message | | | From | Andi Kleen <> | Subject | [PATCH 1/3] DEBUGFS: Automatically create parents for debugfs files v2 | Date | Tue, 13 Dec 2011 13:45:32 -0800 |
| |
From: Andi Kleen <ak@linux.intel.com>
Allow passing path names to debugfs_create* and automatically create the parents. This makes it much simpler for the caller to create hierarchies.
The way the reference counts are handled is admittedly a bit ugly.
There is no way to clean them up currently other than to delete the tree, but that doesn't seem like a big problem for debugfs to leave behind a few empty directories.
v2: Comment fixes based on review comments. v3: satisfy the kernel community's white space obsession. Signed-off-by: Andi Kleen <ak@linux.intel.com> --- fs/debugfs/inode.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++- 1 files changed, 60 insertions(+), 2 deletions(-)
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index f3a257d..0081ac0 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -146,6 +146,55 @@ static struct file_system_type debug_fs_type = { .kill_sb = kill_litter_super, }; +/* + * Created parents stay around later. Sorry, but it shouldn't be a big issue. + */ +static const char *create_parents(const char *name, struct dentry *parent, + struct dentry **pp, int *ref) +{ + char fn[strlen(name) + 1]; + char *tail; + char *s, *p; + struct dentry *new_parent, *dentry, *old_parent = NULL; + + strcpy(fn, name); + tail = strrchr(fn, '/'); + if (!tail) + return name; + tail++; + + s = fn; + while ((p = strsep(&s, "/")) != NULL && p != tail) { + /* + * When the parent already exists, this will error out. + * Ignore that error. We'll just look the dentry up below. + */ + dentry = debugfs_create_dir(p, parent); + + /* Is it there now? */ + mutex_lock(&parent->d_inode->i_mutex); + new_parent = lookup_one_len(p, parent, strlen(p)); + mutex_unlock(&parent->d_inode->i_mutex); + + if (!PTR_ERR(dentry)) + dput(dentry); + if (IS_ERR(new_parent)) + return NULL; + if (old_parent) + dput(old_parent); + if (parent != *pp) + old_parent = parent; + parent = new_parent; + } + if (parent) { + *ref = 1; + *pp = parent; + } + if (old_parent) + dput(old_parent); + return strrchr(name, '/') + 1; +} + static int debugfs_create_by_name(const char *name, mode_t mode, struct dentry *parent, struct dentry **dentry, @@ -153,6 +202,7 @@ static int debugfs_create_by_name(const char *name, mode_t mode, const struct file_operations *fops) { int error = 0; + int ref = 0; /* 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 @@ -161,6 +211,7 @@ static int debugfs_create_by_name(const char *name, mode_t mode, */ if (!parent) parent = debugfs_mount->mnt_sb->s_root; + name = create_parents(name, parent, &parent, &ref); *dentry = NULL; mutex_lock(&parent->d_inode->i_mutex); @@ -185,12 +236,17 @@ static int debugfs_create_by_name(const char *name, mode_t mode, error = PTR_ERR(*dentry); mutex_unlock(&parent->d_inode->i_mutex); + if (ref) + dput(parent); + return error; } /** * debugfs_create_file - create a file in the debugfs filesystem * @name: a pointer to a string containing the name of the file to create. + * This can also contain directories (dir/file), in this case missing + * directories will be automatically created. * @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 paramater is NULL, then the @@ -243,7 +299,8 @@ EXPORT_SYMBOL_GPL(debugfs_create_file); /** * debugfs_create_dir - create a directory in the debugfs filesystem * @name: a pointer to a string containing the name of the directory to - * create. + * create. This can also contain directories (dir/file), in this case + * missing directories will be automatically created. * @parent: a pointer to the parent dentry for this file. This should be a * directory dentry if set. If this paramater is NULL, then the * directory will be created in the root of the debugfs filesystem. @@ -269,7 +326,8 @@ EXPORT_SYMBOL_GPL(debugfs_create_dir); /** * 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. + * create. This can also contain directories (dir/file), in this case + * missing directories will be automatically created * @parent: a pointer to the parent dentry for this symbolic link. This * should be a directory dentry if set. If this paramater is NULL, * then the symbolic link will be created in the root of the debugfs -- 1.7.7.3
| |