diff options
Diffstat (limited to 'fs/debugfs/inode.c')
| -rw-r--r-- | fs/debugfs/inode.c | 368 |
1 files changed, 242 insertions, 126 deletions
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c index 37a8ca7c122..8c41b52da35 100644 --- a/fs/debugfs/inode.c +++ b/fs/debugfs/inode.c @@ -1,5 +1,5 @@ /* - * file.c - part of debugfs, a tiny little debug file system + * inode.c - part of debugfs, a tiny little debug file system * * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com> * Copyright (C) 2004 IBM Inc. @@ -13,9 +13,6 @@ * */ -/* uncomment to get debug messages from the debug filesystem, ah the irony. */ -/* #define DEBUG */ - #include <linux/module.h> #include <linux/fs.h> #include <linux/mount.h> @@ -26,14 +23,18 @@ #include <linux/debugfs.h> #include <linux/fsnotify.h> #include <linux/string.h> +#include <linux/seq_file.h> +#include <linux/parser.h> #include <linux/magic.h> #include <linux/slab.h> +#define DEBUGFS_DEFAULT_MODE 0700 + static struct vfsmount *debugfs_mount; static int debugfs_mount_count; static bool debugfs_registered; -static struct inode *debugfs_get_inode(struct super_block *sb, int mode, dev_t dev, +static struct inode *debugfs_get_inode(struct super_block *sb, umode_t mode, dev_t dev, void *data, const struct file_operations *fops) { @@ -53,13 +54,11 @@ static struct inode *debugfs_get_inode(struct super_block *sb, int mode, dev_t d break; case S_IFLNK: inode->i_op = &debugfs_link_operations; - inode->i_fop = fops; inode->i_private = data; break; case S_IFDIR: inode->i_op = &simple_dir_inode_operations; - inode->i_fop = fops ? fops : &simple_dir_operations; - inode->i_private = data; + inode->i_fop = &simple_dir_operations; /* directory inodes start off with i_nlink == 2 * (for "." entry) */ @@ -72,7 +71,7 @@ static struct inode *debugfs_get_inode(struct super_block *sb, int mode, dev_t d /* SMP-safe */ static int debugfs_mknod(struct inode *dir, struct dentry *dentry, - int mode, dev_t dev, void *data, + umode_t mode, dev_t dev, void *data, const struct file_operations *fops) { struct inode *inode; @@ -90,13 +89,12 @@ static int debugfs_mknod(struct inode *dir, struct dentry *dentry, return error; } -static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, int mode, - void *data, const struct file_operations *fops) +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, data, fops); + res = debugfs_mknod(dir, dentry, mode, 0, NULL, NULL); if (!res) { inc_nlink(dir); fsnotify_mkdir(dir, dentry); @@ -104,14 +102,14 @@ static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, int mode, return res; } -static int debugfs_link(struct inode *dir, struct dentry *dentry, int mode, - void *data, const struct file_operations *fops) +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, fops); + return debugfs_mknod(dir, dentry, mode, 0, data, NULL); } -static int debugfs_create(struct inode *dir, struct dentry *dentry, int mode, +static int debugfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, void *data, const struct file_operations *fops) { int res; @@ -128,11 +126,165 @@ static inline int debugfs_positive(struct dentry *dentry) return dentry->d_inode && !d_unhashed(dentry); } +struct debugfs_mount_opts { + kuid_t uid; + kgid_t gid; + umode_t mode; +}; + +enum { + Opt_uid, + Opt_gid, + Opt_mode, + Opt_err +}; + +static const match_table_t tokens = { + {Opt_uid, "uid=%u"}, + {Opt_gid, "gid=%u"}, + {Opt_mode, "mode=%o"}, + {Opt_err, NULL} +}; + +struct debugfs_fs_info { + struct debugfs_mount_opts mount_opts; +}; + +static int debugfs_parse_options(char *data, struct debugfs_mount_opts *opts) +{ + substring_t args[MAX_OPT_ARGS]; + int option; + int token; + kuid_t uid; + kgid_t gid; + char *p; + + opts->mode = DEBUGFS_DEFAULT_MODE; + + while ((p = strsep(&data, ",")) != NULL) { + if (!*p) + continue; + + token = match_token(p, tokens, args); + switch (token) { + case Opt_uid: + if (match_int(&args[0], &option)) + return -EINVAL; + uid = make_kuid(current_user_ns(), option); + if (!uid_valid(uid)) + return -EINVAL; + opts->uid = uid; + break; + case Opt_gid: + if (match_int(&args[0], &option)) + return -EINVAL; + gid = make_kgid(current_user_ns(), option); + if (!gid_valid(gid)) + return -EINVAL; + opts->gid = gid; + break; + case Opt_mode: + if (match_octal(&args[0], &option)) + return -EINVAL; + opts->mode = option & S_IALLUGO; + break; + /* + * We might like to report bad mount options here; + * but traditionally debugfs has ignored all mount options + */ + } + } + + return 0; +} + +static int debugfs_apply_options(struct super_block *sb) +{ + struct debugfs_fs_info *fsi = sb->s_fs_info; + struct inode *inode = sb->s_root->d_inode; + struct debugfs_mount_opts *opts = &fsi->mount_opts; + + inode->i_mode &= ~S_IALLUGO; + inode->i_mode |= opts->mode; + + inode->i_uid = opts->uid; + inode->i_gid = opts->gid; + + return 0; +} + +static int debugfs_remount(struct super_block *sb, int *flags, char *data) +{ + int err; + struct debugfs_fs_info *fsi = sb->s_fs_info; + + sync_filesystem(sb); + err = debugfs_parse_options(data, &fsi->mount_opts); + if (err) + goto fail; + + debugfs_apply_options(sb); + +fail: + return err; +} + +static int debugfs_show_options(struct seq_file *m, struct dentry *root) +{ + struct debugfs_fs_info *fsi = root->d_sb->s_fs_info; + struct debugfs_mount_opts *opts = &fsi->mount_opts; + + if (!uid_eq(opts->uid, GLOBAL_ROOT_UID)) + seq_printf(m, ",uid=%u", + from_kuid_munged(&init_user_ns, opts->uid)); + if (!gid_eq(opts->gid, GLOBAL_ROOT_GID)) + seq_printf(m, ",gid=%u", + from_kgid_munged(&init_user_ns, opts->gid)); + if (opts->mode != DEBUGFS_DEFAULT_MODE) + seq_printf(m, ",mode=%o", opts->mode); + + return 0; +} + +static const struct super_operations debugfs_super_operations = { + .statfs = simple_statfs, + .remount_fs = debugfs_remount, + .show_options = debugfs_show_options, +}; + static int debug_fill_super(struct super_block *sb, void *data, int silent) { static struct tree_descr debug_files[] = {{""}}; + struct debugfs_fs_info *fsi; + int err; - return simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); + save_mount_options(sb, data); + + fsi = kzalloc(sizeof(struct debugfs_fs_info), GFP_KERNEL); + sb->s_fs_info = fsi; + if (!fsi) { + err = -ENOMEM; + goto fail; + } + + err = debugfs_parse_options(data, &fsi->mount_opts); + if (err) + goto fail; + + err = simple_fill_super(sb, DEBUGFS_MAGIC, debug_files); + if (err) + goto fail; + + sb->s_op = &debugfs_super_operations; + + debugfs_apply_options(sb); + + return 0; + +fail: + kfree(fsi); + sb->s_fs_info = NULL; + return err; } static struct dentry *debug_mount(struct file_system_type *fs_type, @@ -148,14 +300,21 @@ static struct file_system_type debug_fs_type = { .mount = debug_mount, .kill_sb = kill_litter_super, }; +MODULE_ALIAS_FS("debugfs"); -static int debugfs_create_by_name(const char *name, mode_t mode, - struct dentry *parent, - struct dentry **dentry, - void *data, - const struct file_operations *fops) +static struct dentry *__create_file(const char *name, umode_t mode, + struct dentry *parent, void *data, + const struct file_operations *fops) { - int error = 0; + struct dentry *dentry = NULL; + int error; + + pr_debug("debugfs: creating file '%s'\n",name); + + error = simple_pin_fs(&debug_fs_type, &debugfs_mount, + &debugfs_mount_count); + if (error) + goto exit; /* 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 @@ -163,32 +322,36 @@ static int debugfs_create_by_name(const char *name, mode_t mode, * have around. */ if (!parent) - parent = debugfs_mount->mnt_sb->s_root; + parent = debugfs_mount->mnt_root; - *dentry = NULL; mutex_lock(&parent->d_inode->i_mutex); - *dentry = lookup_one_len(name, parent, strlen(name)); - if (!IS_ERR(*dentry)) { + 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, - data, fops); + error = debugfs_mkdir(parent->d_inode, dentry, mode); + break; case S_IFLNK: - error = debugfs_link(parent->d_inode, *dentry, mode, - data, fops); + error = debugfs_link(parent->d_inode, dentry, mode, + data); break; default: - error = debugfs_create(parent->d_inode, *dentry, mode, + error = debugfs_create(parent->d_inode, dentry, mode, data, fops); break; } - dput(*dentry); + dput(dentry); } else - error = PTR_ERR(*dentry); + error = PTR_ERR(dentry); mutex_unlock(&parent->d_inode->i_mutex); - return error; + if (error) { + dentry = NULL; + simple_release_fs(&debugfs_mount, &debugfs_mount_count); + } +exit: + return dentry; } /** @@ -196,7 +359,7 @@ static int debugfs_create_by_name(const char *name, mode_t mode, * @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 paramater is NULL, then the + * 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 @@ -217,29 +380,19 @@ static int debugfs_create_by_name(const char *name, mode_t mode, * If debugfs is not enabled in the kernel, the value -%ENODEV will be * returned. */ -struct dentry *debugfs_create_file(const char *name, mode_t mode, +struct dentry *debugfs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops) { - struct dentry *dentry = NULL; - int error; - - pr_debug("debugfs: creating file '%s'\n",name); - - error = simple_pin_fs(&debug_fs_type, &debugfs_mount, - &debugfs_mount_count); - if (error) - goto exit; - - error = debugfs_create_by_name(name, mode, parent, &dentry, - data, fops); - if (error) { - dentry = NULL; - simple_release_fs(&debugfs_mount, &debugfs_mount_count); - goto exit; + switch (mode & S_IFMT) { + case S_IFREG: + case 0: + break; + default: + BUG(); } -exit: - return dentry; + + return __create_file(name, mode, parent, data, fops); } EXPORT_SYMBOL_GPL(debugfs_create_file); @@ -248,7 +401,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_file); * @name: a pointer to a string containing the name of the directory to * create. * @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 dentry if set. If this parameter is NULL, then the * directory will be created in the root of the debugfs filesystem. * * This function creates a directory in debugfs with the given name. @@ -263,8 +416,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_file); */ struct dentry *debugfs_create_dir(const char *name, struct dentry *parent) { - return debugfs_create_file(name, - S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, + return __create_file(name, S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, parent, NULL, NULL); } EXPORT_SYMBOL_GPL(debugfs_create_dir); @@ -274,7 +426,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_dir); * @name: a pointer to a string containing the name of the symbolic link to * create. * @parent: a pointer to the parent dentry for this symbolic link. This - * should be a directory dentry if set. If this paramater is NULL, + * should be a directory dentry if set. If this parameter is NULL, * then the symbolic link will be created in the root of the debugfs * filesystem. * @target: a pointer to a string containing the path to the target of the @@ -302,15 +454,14 @@ struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent, if (!link) return NULL; - result = debugfs_create_file(name, S_IFLNK | S_IRWXUGO, parent, link, - NULL); + result = __create_file(name, S_IFLNK | S_IRWXUGO, parent, link, NULL); if (!result) kfree(link); return result; } EXPORT_SYMBOL_GPL(debugfs_create_symlink); -static void __debugfs_remove(struct dentry *dentry, struct dentry *parent) +static int __debugfs_remove(struct dentry *dentry, struct dentry *parent) { int ret = 0; @@ -333,6 +484,7 @@ static void __debugfs_remove(struct dentry *dentry, struct dentry *parent) dput(dentry); } } + return ret; } /** @@ -351,8 +503,9 @@ static void __debugfs_remove(struct dentry *dentry, struct dentry *parent) void debugfs_remove(struct dentry *dentry) { struct dentry *parent; - - if (!dentry) + int ret; + + if (IS_ERR_OR_NULL(dentry)) return; parent = dentry->d_parent; @@ -360,9 +513,10 @@ void debugfs_remove(struct dentry *dentry) return; mutex_lock(&parent->d_inode->i_mutex); - __debugfs_remove(dentry, parent); + ret = __debugfs_remove(dentry, parent); mutex_unlock(&parent->d_inode->i_mutex); - simple_release_fs(&debugfs_mount, &debugfs_mount_count); + if (!ret) + simple_release_fs(&debugfs_mount, &debugfs_mount_count); } EXPORT_SYMBOL_GPL(debugfs_remove); @@ -380,10 +534,9 @@ EXPORT_SYMBOL_GPL(debugfs_remove); */ void debugfs_remove_recursive(struct dentry *dentry) { - struct dentry *child; - struct dentry *parent; + struct dentry *child, *next, *parent; - if (!dentry) + if (IS_ERR_OR_NULL(dentry)) return; parent = dentry->d_parent; @@ -391,61 +544,36 @@ void debugfs_remove_recursive(struct dentry *dentry) return; parent = dentry; + down: mutex_lock(&parent->d_inode->i_mutex); + list_for_each_entry_safe(child, next, &parent->d_subdirs, d_u.d_child) { + if (!debugfs_positive(child)) + continue; - while (1) { - /* - * When all dentries under "parent" has been removed, - * walk up the tree until we reach our starting point. - */ - if (list_empty(&parent->d_subdirs)) { - mutex_unlock(&parent->d_inode->i_mutex); - if (parent == dentry) - break; - parent = parent->d_parent; - mutex_lock(&parent->d_inode->i_mutex); - } - child = list_entry(parent->d_subdirs.next, struct dentry, - d_u.d_child); - next_sibling: - - /* - * If "child" isn't empty, walk down the tree and - * remove all its descendants first. - */ + /* perhaps simple_empty(child) makes more sense */ if (!list_empty(&child->d_subdirs)) { mutex_unlock(&parent->d_inode->i_mutex); parent = child; - mutex_lock(&parent->d_inode->i_mutex); - continue; + goto down; } - __debugfs_remove(child, parent); - if (parent->d_subdirs.next == &child->d_u.d_child) { - /* - * Try the next sibling. - */ - if (child->d_u.d_child.next != &parent->d_subdirs) { - child = list_entry(child->d_u.d_child.next, - struct dentry, - d_u.d_child); - goto next_sibling; - } - - /* - * Avoid infinite loop if we fail to remove - * one dentry. - */ - mutex_unlock(&parent->d_inode->i_mutex); - break; - } - simple_release_fs(&debugfs_mount, &debugfs_mount_count); + up: + if (!__debugfs_remove(child, parent)) + simple_release_fs(&debugfs_mount, &debugfs_mount_count); } - parent = dentry->d_parent; + mutex_unlock(&parent->d_inode->i_mutex); + child = parent; + parent = parent->d_parent; mutex_lock(&parent->d_inode->i_mutex); - __debugfs_remove(dentry, parent); + + if (child != dentry) { + next = list_next_entry(child, d_u.d_child); + goto up; + } + + if (!__debugfs_remove(child, parent)) + simple_release_fs(&debugfs_mount, &debugfs_mount_count); mutex_unlock(&parent->d_inode->i_mutex); - simple_release_fs(&debugfs_mount, &debugfs_mount_count); } EXPORT_SYMBOL_GPL(debugfs_remove_recursive); @@ -540,17 +668,5 @@ static int __init debugfs_init(void) return retval; } - -static void __exit debugfs_exit(void) -{ - debugfs_registered = false; - - simple_release_fs(&debugfs_mount, &debugfs_mount_count); - unregister_filesystem(&debug_fs_type); - kobject_put(debug_kobj); -} - core_initcall(debugfs_init); -module_exit(debugfs_exit); -MODULE_LICENSE("GPL"); |