From 3d0f89bb169482d26d5aa4e82e763077e7e9bc4d Mon Sep 17 00:00:00 2001 From: Joel Becker Date: Wed, 25 Jan 2006 13:31:07 -0800 Subject: [PATCH] configfs: Add permission and ownership to configfs objects. configfs always made item and attribute ownership root.root and permissions based on a umask of 022. Add ->setattr() to allow chown(2)/chmod(2), and persist the changes for the lifetime of the items and attributes. Signed-off-by: Joel Becker Signed-off-by: Mark Fasheh --- .../filesystems/configfs/configfs_example.c | 2 + fs/configfs/configfs_internal.h | 11 +- fs/configfs/dir.c | 36 ++++-- fs/configfs/file.c | 19 +-- fs/configfs/inode.c | 117 ++++++++++++++++-- fs/configfs/mount.c | 28 ++++- fs/configfs/symlink.c | 1 + include/linux/configfs.h | 2 +- 8 files changed, 179 insertions(+), 37 deletions(-) diff --git a/Documentation/filesystems/configfs/configfs_example.c b/Documentation/filesystems/configfs/configfs_example.c index f3c6e4946f9..3d4713a6c20 100644 --- a/Documentation/filesystems/configfs/configfs_example.c +++ b/Documentation/filesystems/configfs/configfs_example.c @@ -320,6 +320,7 @@ static struct config_item_type simple_children_type = { .ct_item_ops = &simple_children_item_ops, .ct_group_ops = &simple_children_group_ops, .ct_attrs = simple_children_attrs, + .ct_owner = THIS_MODULE, }; static struct configfs_subsystem simple_children_subsys = { @@ -403,6 +404,7 @@ static struct config_item_type group_children_type = { .ct_item_ops = &group_children_item_ops, .ct_group_ops = &group_children_group_ops, .ct_attrs = group_children_attrs, + .ct_owner = THIS_MODULE, }; static struct configfs_subsystem group_children_subsys = { diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h index 8899d9c5f6b..f70e46951b3 100644 --- a/fs/configfs/configfs_internal.h +++ b/fs/configfs/configfs_internal.h @@ -36,6 +36,7 @@ struct configfs_dirent { int s_type; umode_t s_mode; struct dentry * s_dentry; + struct iattr * s_iattr; }; #define CONFIGFS_ROOT 0x0001 @@ -48,10 +49,11 @@ struct configfs_dirent { #define CONFIGFS_NOT_PINNED (CONFIGFS_ITEM_ATTR) extern struct vfsmount * configfs_mount; +extern kmem_cache_t *configfs_dir_cachep; extern int configfs_is_root(struct config_item *item); -extern struct inode * configfs_new_inode(mode_t mode); +extern struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent *); extern int configfs_create(struct dentry *, int mode, int (*init)(struct inode *)); extern int configfs_create_file(struct config_item *, const struct configfs_attribute *); @@ -63,6 +65,7 @@ extern void configfs_hash_and_remove(struct dentry * dir, const char * name); extern const unsigned char * configfs_get_name(struct configfs_dirent *sd); extern void configfs_drop_dentry(struct configfs_dirent *sd, struct dentry *parent); +extern int configfs_setattr(struct dentry *dentry, struct iattr *iattr); extern int configfs_pin_fs(void); extern void configfs_release_fs(void); @@ -120,8 +123,10 @@ static inline struct config_item *configfs_get_config_item(struct dentry *dentry static inline void release_configfs_dirent(struct configfs_dirent * sd) { - if (!(sd->s_type & CONFIGFS_ROOT)) - kfree(sd); + if (!(sd->s_type & CONFIGFS_ROOT)) { + kfree(sd->s_iattr); + kmem_cache_free(configfs_dir_cachep, sd); + } } static inline struct configfs_dirent * configfs_get(struct configfs_dirent * sd) diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c index b668ec61527..ca60e3abef4 100644 --- a/fs/configfs/dir.c +++ b/fs/configfs/dir.c @@ -72,7 +72,7 @@ static struct configfs_dirent *configfs_new_dirent(struct configfs_dirent * pare { struct configfs_dirent * sd; - sd = kmalloc(sizeof(*sd), GFP_KERNEL); + sd = kmem_cache_alloc(configfs_dir_cachep, GFP_KERNEL); if (!sd) return NULL; @@ -136,13 +136,19 @@ static int create_dir(struct config_item * k, struct dentry * p, int error; umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO; - error = configfs_create(d, mode, init_dir); + error = configfs_make_dirent(p->d_fsdata, d, k, mode, + CONFIGFS_DIR); if (!error) { - error = configfs_make_dirent(p->d_fsdata, d, k, mode, - CONFIGFS_DIR); + error = configfs_create(d, mode, init_dir); if (!error) { p->d_inode->i_nlink++; (d)->d_op = &configfs_dentry_ops; + } else { + struct configfs_dirent *sd = d->d_fsdata; + if (sd) { + list_del_init(&sd->s_sibling); + configfs_put(sd); + } } } return error; @@ -182,12 +188,19 @@ int configfs_create_link(struct configfs_symlink *sl, int err = 0; umode_t mode = S_IFLNK | S_IRWXUGO; - err = configfs_create(dentry, mode, init_symlink); + err = configfs_make_dirent(parent->d_fsdata, dentry, sl, mode, + CONFIGFS_ITEM_LINK); if (!err) { - err = configfs_make_dirent(parent->d_fsdata, dentry, sl, - mode, CONFIGFS_ITEM_LINK); + err = configfs_create(dentry, mode, init_symlink); if (!err) dentry->d_op = &configfs_dentry_ops; + else { + struct configfs_dirent *sd = dentry->d_fsdata; + if (sd) { + list_del_init(&sd->s_sibling); + configfs_put(sd); + } + } } return err; } @@ -241,13 +254,15 @@ static int configfs_attach_attr(struct configfs_dirent * sd, struct dentry * den struct configfs_attribute * attr = sd->s_element; int error; + dentry->d_fsdata = configfs_get(sd); + sd->s_dentry = dentry; error = configfs_create(dentry, (attr->ca_mode & S_IALLUGO) | S_IFREG, init_file); - if (error) + if (error) { + configfs_put(sd); return error; + } dentry->d_op = &configfs_dentry_ops; - dentry->d_fsdata = configfs_get(sd); - sd->s_dentry = dentry; d_rehash(dentry); return 0; @@ -839,6 +854,7 @@ struct inode_operations configfs_dir_inode_operations = { .symlink = configfs_symlink, .unlink = configfs_unlink, .lookup = configfs_lookup, + .setattr = configfs_setattr, }; #if 0 diff --git a/fs/configfs/file.c b/fs/configfs/file.c index c26cd61f13a..3921920d871 100644 --- a/fs/configfs/file.c +++ b/fs/configfs/file.c @@ -26,7 +26,6 @@ #include #include -#include #include #include #include @@ -150,7 +149,7 @@ out: /** * fill_write_buffer - copy buffer from userspace. * @buffer: data buffer for file. - * @userbuf: data from user. + * @buf: data from user. * @count: number of bytes in @userbuf. * * Allocate @buffer->page if it hasn't been already, then @@ -177,8 +176,9 @@ fill_write_buffer(struct configfs_buffer * buffer, const char __user * buf, size /** * flush_write_buffer - push buffer to config_item. - * @file: file pointer. + * @dentry: dentry to the attribute * @buffer: data buffer for file. + * @count: number of bytes * * Get the correct pointers for the config_item and the attribute we're * dealing with, then call the store() method for the attribute, @@ -217,15 +217,16 @@ static ssize_t configfs_write_file(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct configfs_buffer * buffer = file->private_data; + ssize_t len; down(&buffer->sem); - count = fill_write_buffer(buffer,buf,count); - if (count > 0) - count = flush_write_buffer(file->f_dentry,buffer,count); - if (count > 0) - *ppos += count; + len = fill_write_buffer(buffer, buf, count); + if (len > 0) + len = flush_write_buffer(file->f_dentry, buffer, count); + if (len > 0) + *ppos += len; up(&buffer->sem); - return count; + return len; } static int check_perm(struct inode * inode, struct file * file) diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c index 6577c588de9..737842f2764 100644 --- a/fs/configfs/inode.c +++ b/fs/configfs/inode.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include "configfs_internal.h" @@ -48,18 +49,107 @@ static struct backing_dev_info configfs_backing_dev_info = { .capabilities = BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_WRITEBACK, }; -struct inode * configfs_new_inode(mode_t mode) +static struct inode_operations configfs_inode_operations ={ + .setattr = configfs_setattr, +}; + +int configfs_setattr(struct dentry * dentry, struct iattr * iattr) +{ + struct inode * inode = dentry->d_inode; + struct configfs_dirent * sd = dentry->d_fsdata; + struct iattr * sd_iattr; + unsigned int ia_valid = iattr->ia_valid; + int error; + + if (!sd) + return -EINVAL; + + sd_iattr = sd->s_iattr; + + error = inode_change_ok(inode, iattr); + if (error) + return error; + + error = inode_setattr(inode, iattr); + if (error) + return error; + + if (!sd_iattr) { + /* setting attributes for the first time, allocate now */ + sd_iattr = kmalloc(sizeof(struct iattr), GFP_KERNEL); + if (!sd_iattr) + return -ENOMEM; + /* assign default attributes */ + memset(sd_iattr, 0, sizeof(struct iattr)); + sd_iattr->ia_mode = sd->s_mode; + sd_iattr->ia_uid = 0; + sd_iattr->ia_gid = 0; + sd_iattr->ia_atime = sd_iattr->ia_mtime = sd_iattr->ia_ctime = CURRENT_TIME; + sd->s_iattr = sd_iattr; + } + + /* attributes were changed atleast once in past */ + + if (ia_valid & ATTR_UID) + sd_iattr->ia_uid = iattr->ia_uid; + if (ia_valid & ATTR_GID) + sd_iattr->ia_gid = iattr->ia_gid; + if (ia_valid & ATTR_ATIME) + sd_iattr->ia_atime = timespec_trunc(iattr->ia_atime, + inode->i_sb->s_time_gran); + if (ia_valid & ATTR_MTIME) + sd_iattr->ia_mtime = timespec_trunc(iattr->ia_mtime, + inode->i_sb->s_time_gran); + if (ia_valid & ATTR_CTIME) + sd_iattr->ia_ctime = timespec_trunc(iattr->ia_ctime, + inode->i_sb->s_time_gran); + if (ia_valid & ATTR_MODE) { + umode_t mode = iattr->ia_mode; + + if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID)) + mode &= ~S_ISGID; + sd_iattr->ia_mode = sd->s_mode = mode; + } + + return error; +} + +static inline void set_default_inode_attr(struct inode * inode, mode_t mode) +{ + inode->i_mode = mode; + inode->i_uid = 0; + inode->i_gid = 0; + inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; +} + +static inline void set_inode_attr(struct inode * inode, struct iattr * iattr) +{ + inode->i_mode = iattr->ia_mode; + inode->i_uid = iattr->ia_uid; + inode->i_gid = iattr->ia_gid; + inode->i_atime = iattr->ia_atime; + inode->i_mtime = iattr->ia_mtime; + inode->i_ctime = iattr->ia_ctime; +} + +struct inode * configfs_new_inode(mode_t mode, struct configfs_dirent * sd) { struct inode * inode = new_inode(configfs_sb); if (inode) { - inode->i_mode = mode; - inode->i_uid = 0; - inode->i_gid = 0; inode->i_blksize = PAGE_CACHE_SIZE; inode->i_blocks = 0; - inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; inode->i_mapping->a_ops = &configfs_aops; inode->i_mapping->backing_dev_info = &configfs_backing_dev_info; + inode->i_op = &configfs_inode_operations; + + if (sd->s_iattr) { + /* sysfs_dirent has non-default attributes + * get them for the new inode from persistent copy + * in sysfs_dirent + */ + set_inode_attr(inode, sd->s_iattr); + } else + set_default_inode_attr(inode, mode); } return inode; } @@ -70,7 +160,8 @@ int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode * struct inode * inode = NULL; if (dentry) { if (!dentry->d_inode) { - if ((inode = configfs_new_inode(mode))) { + struct configfs_dirent *sd = dentry->d_fsdata; + if ((inode = configfs_new_inode(mode, sd))) { if (dentry->d_parent && dentry->d_parent->d_inode) { struct inode *p_inode = dentry->d_parent->d_inode; p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME; @@ -103,7 +194,7 @@ int configfs_create(struct dentry * dentry, int mode, int (*init)(struct inode * */ const unsigned char * configfs_get_name(struct configfs_dirent *sd) { - struct attribute * attr; + struct configfs_attribute *attr; if (!sd || !sd->s_element) BUG(); @@ -114,7 +205,7 @@ const unsigned char * configfs_get_name(struct configfs_dirent *sd) if (sd->s_type & CONFIGFS_ITEM_ATTR) { attr = sd->s_element; - return attr->name; + return attr->ca_name; } return NULL; } @@ -130,13 +221,17 @@ void configfs_drop_dentry(struct configfs_dirent * sd, struct dentry * parent) if (dentry) { spin_lock(&dcache_lock); + spin_lock(&dentry->d_lock); if (!(d_unhashed(dentry) && dentry->d_inode)) { dget_locked(dentry); __d_drop(dentry); + spin_unlock(&dentry->d_lock); spin_unlock(&dcache_lock); simple_unlink(parent->d_inode, dentry); - } else + } else { + spin_unlock(&dentry->d_lock); spin_unlock(&dcache_lock); + } } } @@ -145,6 +240,10 @@ void configfs_hash_and_remove(struct dentry * dir, const char * name) struct configfs_dirent * sd; struct configfs_dirent * parent_sd = dir->d_fsdata; + if (dir->d_inode == NULL) + /* no inode means this hasn't been made visible yet */ + return; + mutex_lock(&dir->d_inode->i_mutex); list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { if (!sd->s_element) diff --git a/fs/configfs/mount.c b/fs/configfs/mount.c index 1a2f6f6a4d9..f920d30478e 100644 --- a/fs/configfs/mount.c +++ b/fs/configfs/mount.c @@ -38,6 +38,7 @@ struct vfsmount * configfs_mount = NULL; struct super_block * configfs_sb = NULL; +kmem_cache_t *configfs_dir_cachep; static int configfs_mnt_count = 0; static struct super_operations configfs_ops = { @@ -62,6 +63,7 @@ static struct configfs_dirent configfs_root = { .s_children = LIST_HEAD_INIT(configfs_root.s_children), .s_element = &configfs_root_group.cg_item, .s_type = CONFIGFS_ROOT, + .s_iattr = NULL, }; static int configfs_fill_super(struct super_block *sb, void *data, int silent) @@ -73,9 +75,11 @@ static int configfs_fill_super(struct super_block *sb, void *data, int silent) sb->s_blocksize_bits = PAGE_CACHE_SHIFT; sb->s_magic = CONFIGFS_MAGIC; sb->s_op = &configfs_ops; + sb->s_time_gran = 1; configfs_sb = sb; - inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO); + inode = configfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, + &configfs_root); if (inode) { inode->i_op = &configfs_dir_inode_operations; inode->i_fop = &configfs_dir_operations; @@ -128,19 +132,31 @@ static decl_subsys(config, NULL, NULL); static int __init configfs_init(void) { - int err; + int err = -ENOMEM; + + configfs_dir_cachep = kmem_cache_create("configfs_dir_cache", + sizeof(struct configfs_dirent), + 0, 0, NULL, NULL); + if (!configfs_dir_cachep) + goto out; kset_set_kset_s(&config_subsys, kernel_subsys); err = subsystem_register(&config_subsys); - if (err) - return err; + if (err) { + kmem_cache_destroy(configfs_dir_cachep); + configfs_dir_cachep = NULL; + goto out; + } err = register_filesystem(&configfs_fs_type); if (err) { printk(KERN_ERR "configfs: Unable to register filesystem!\n"); subsystem_unregister(&config_subsys); + kmem_cache_destroy(configfs_dir_cachep); + configfs_dir_cachep = NULL; } +out: return err; } @@ -148,11 +164,13 @@ static void __exit configfs_exit(void) { unregister_filesystem(&configfs_fs_type); subsystem_unregister(&config_subsys); + kmem_cache_destroy(configfs_dir_cachep); + configfs_dir_cachep = NULL; } MODULE_AUTHOR("Oracle"); MODULE_LICENSE("GPL"); -MODULE_VERSION("0.0.1"); +MODULE_VERSION("0.0.2"); MODULE_DESCRIPTION("Simple RAM filesystem for user driven kernel subsystem configuration."); module_init(configfs_init); diff --git a/fs/configfs/symlink.c b/fs/configfs/symlink.c index 50f5840521a..99137026b40 100644 --- a/fs/configfs/symlink.c +++ b/fs/configfs/symlink.c @@ -277,5 +277,6 @@ struct inode_operations configfs_symlink_inode_operations = { .follow_link = configfs_follow_link, .readlink = generic_readlink, .put_link = configfs_put_link, + .setattr = configfs_setattr, }; diff --git a/include/linux/configfs.h b/include/linux/configfs.h index acffb8c9073..a7f01502753 100644 --- a/include/linux/configfs.h +++ b/include/linux/configfs.h @@ -126,7 +126,7 @@ extern struct config_item *config_group_find_obj(struct config_group *, const ch struct configfs_attribute { - char *ca_name; + const char *ca_name; struct module *ca_owner; mode_t ca_mode; }; -- 2.41.1