Copy missing devtmpfs.c and posix_acl.c from mainline 3.18.19 --- diff --git a/drivers/base/devtmpfs.c b/drivers/base/devtmpfs.c new file mode 100644 index 0000000..25798db --- /dev/null +++ b/drivers/base/devtmpfs.c @@ -0,0 +1,443 @@ +/* + * devtmpfs - kernel-maintained tmpfs-based /dev + * + * Copyright (C) 2009, Kay Sievers + * + * During bootup, before any driver core device is registered, + * devtmpfs, a tmpfs-based filesystem is created. Every driver-core + * device which requests a device node, will add a node in this + * filesystem. + * By default, all devices are named after the name of the device, + * owned by root and have a default mode of 0600. Subsystems can + * overwrite the default setting if needed. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include "base.h" + +static struct task_struct *thread; + +#if defined CONFIG_DEVTMPFS_MOUNT +static int mount_dev = 1; +#else +static int mount_dev; +#endif + +static DEFINE_SPINLOCK(req_lock); + +static struct req { + struct req *next; + struct completion done; + int err; + const char *name; + umode_t mode; /* 0 => delete */ + kuid_t uid; + kgid_t gid; + struct device *dev; +} *requests; + +static int __init mount_param(char *str) +{ + mount_dev = simple_strtoul(str, NULL, 0); + return 1; +} +__setup("devtmpfs.mount=", mount_param); + +static struct dentry *dev_mount(struct file_system_type *fs_type, int flags, + const char *dev_name, void *data) +{ +#ifdef CONFIG_TMPFS + return mount_single(fs_type, flags, data, shmem_fill_super); +#else + return mount_single(fs_type, flags, data, ramfs_fill_super); +#endif +} + +static struct file_system_type dev_fs_type = { + .name = "devtmpfs", + .mount = dev_mount, + .kill_sb = kill_litter_super, +}; + +#ifdef CONFIG_BLOCK +static inline int is_blockdev(struct device *dev) +{ + return dev->class == &block_class; +} +#else +static inline int is_blockdev(struct device *dev) { return 0; } +#endif + +int devtmpfs_create_node(struct device *dev) +{ + const char *tmp = NULL; + struct req req; + + if (!thread) + return 0; + + req.mode = 0; + req.uid = GLOBAL_ROOT_UID; + req.gid = GLOBAL_ROOT_GID; + req.name = device_get_devnode(dev, &req.mode, &req.uid, &req.gid, &tmp); + if (!req.name) + return -ENOMEM; + + if (req.mode == 0) + req.mode = 0600; + if (is_blockdev(dev)) + req.mode |= S_IFBLK; + else + req.mode |= S_IFCHR; + + req.dev = dev; + + init_completion(&req.done); + + spin_lock(&req_lock); + req.next = requests; + requests = &req; + spin_unlock(&req_lock); + + wake_up_process(thread); + wait_for_completion(&req.done); + + kfree(tmp); + + return req.err; +} + +int devtmpfs_delete_node(struct device *dev) +{ + const char *tmp = NULL; + struct req req; + + if (!thread) + return 0; + + req.name = device_get_devnode(dev, NULL, NULL, NULL, &tmp); + if (!req.name) + return -ENOMEM; + + req.mode = 0; + req.dev = dev; + + init_completion(&req.done); + + spin_lock(&req_lock); + req.next = requests; + requests = &req; + spin_unlock(&req_lock); + + wake_up_process(thread); + wait_for_completion(&req.done); + + kfree(tmp); + return req.err; +} + +static int dev_mkdir(const char *name, umode_t mode) +{ + struct dentry *dentry; + struct path path; + int err; + + dentry = kern_path_create(AT_FDCWD, name, &path, LOOKUP_DIRECTORY); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + err = vfs_mkdir(path.dentry->d_inode, dentry, mode); + if (!err) + /* mark as kernel-created inode */ + dentry->d_inode->i_private = &thread; + done_path_create(&path, dentry); + return err; +} + +static int create_path(const char *nodepath) +{ + char *path; + char *s; + int err = 0; + + /* parent directories do not exist, create them */ + path = kstrdup(nodepath, GFP_KERNEL); + if (!path) + return -ENOMEM; + + s = path; + for (;;) { + s = strchr(s, '/'); + if (!s) + break; + s[0] = '\0'; + err = dev_mkdir(path, 0755); + if (err && err != -EEXIST) + break; + s[0] = '/'; + s++; + } + kfree(path); + return err; +} + +static int handle_create(const char *nodename, umode_t mode, kuid_t uid, + kgid_t gid, struct device *dev) +{ + struct dentry *dentry; + struct path path; + int err; + + dentry = kern_path_create(AT_FDCWD, nodename, &path, 0); + if (dentry == ERR_PTR(-ENOENT)) { + create_path(nodename); + dentry = kern_path_create(AT_FDCWD, nodename, &path, 0); + } + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + err = vfs_mknod(path.dentry->d_inode, dentry, mode, dev->devt); + if (!err) { + struct iattr newattrs; + + newattrs.ia_mode = mode; + newattrs.ia_uid = uid; + newattrs.ia_gid = gid; + newattrs.ia_valid = ATTR_MODE|ATTR_UID|ATTR_GID; + mutex_lock(&dentry->d_inode->i_mutex); + notify_change(dentry, &newattrs, NULL); + mutex_unlock(&dentry->d_inode->i_mutex); + + /* mark as kernel-created inode */ + dentry->d_inode->i_private = &thread; + } + done_path_create(&path, dentry); + return err; +} + +static int dev_rmdir(const char *name) +{ + struct path parent; + struct dentry *dentry; + int err; + + dentry = kern_path_locked(name, &parent); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + if (dentry->d_inode) { + if (dentry->d_inode->i_private == &thread) + err = vfs_rmdir(parent.dentry->d_inode, dentry); + else + err = -EPERM; + } else { + err = -ENOENT; + } + dput(dentry); + mutex_unlock(&parent.dentry->d_inode->i_mutex); + path_put(&parent); + return err; +} + +static int delete_path(const char *nodepath) +{ + const char *path; + int err = 0; + + path = kstrdup(nodepath, GFP_KERNEL); + if (!path) + return -ENOMEM; + + for (;;) { + char *base; + + base = strrchr(path, '/'); + if (!base) + break; + base[0] = '\0'; + err = dev_rmdir(path); + if (err) + break; + } + + kfree(path); + return err; +} + +static int dev_mynode(struct device *dev, struct inode *inode, struct kstat *stat) +{ + /* did we create it */ + if (inode->i_private != &thread) + return 0; + + /* does the dev_t match */ + if (is_blockdev(dev)) { + if (!S_ISBLK(stat->mode)) + return 0; + } else { + if (!S_ISCHR(stat->mode)) + return 0; + } + if (stat->rdev != dev->devt) + return 0; + + /* ours */ + return 1; +} + +static int handle_remove(const char *nodename, struct device *dev) +{ + struct path parent; + struct dentry *dentry; + int deleted = 0; + int err; + + dentry = kern_path_locked(nodename, &parent); + if (IS_ERR(dentry)) + return PTR_ERR(dentry); + + if (dentry->d_inode) { + struct kstat stat; + struct path p = {.mnt = parent.mnt, .dentry = dentry}; + err = vfs_getattr(&p, &stat); + if (!err && dev_mynode(dev, dentry->d_inode, &stat)) { + struct iattr newattrs; + /* + * before unlinking this node, reset permissions + * of possible references like hardlinks + */ + newattrs.ia_uid = GLOBAL_ROOT_UID; + newattrs.ia_gid = GLOBAL_ROOT_GID; + newattrs.ia_mode = stat.mode & ~0777; + newattrs.ia_valid = + ATTR_UID|ATTR_GID|ATTR_MODE; + mutex_lock(&dentry->d_inode->i_mutex); + notify_change(dentry, &newattrs, NULL); + mutex_unlock(&dentry->d_inode->i_mutex); + err = vfs_unlink(parent.dentry->d_inode, dentry, NULL); + if (!err || err == -ENOENT) + deleted = 1; + } + } else { + err = -ENOENT; + } + dput(dentry); + mutex_unlock(&parent.dentry->d_inode->i_mutex); + + path_put(&parent); + if (deleted && strchr(nodename, '/')) + delete_path(nodename); + return err; +} + +/* + * If configured, or requested by the commandline, devtmpfs will be + * auto-mounted after the kernel mounted the root filesystem. + */ +int devtmpfs_mount(const char *mntdir) +{ + int err; + + if (!mount_dev) + return 0; + + if (!thread) + return 0; + + err = sys_mount("devtmpfs", (char *)mntdir, "devtmpfs", MS_SILENT, NULL); + if (err) + printk(KERN_INFO "devtmpfs: error mounting %i\n", err); + else + printk(KERN_INFO "devtmpfs: mounted\n"); + return err; +} + +static DECLARE_COMPLETION(setup_done); + +static int handle(const char *name, umode_t mode, kuid_t uid, kgid_t gid, + struct device *dev) +{ + if (mode) + return handle_create(name, mode, uid, gid, dev); + else + return handle_remove(name, dev); +} + +static int devtmpfsd(void *p) +{ + char options[] = "mode=0755"; + int *err = p; + *err = sys_unshare(CLONE_NEWNS); + if (*err) + goto out; + *err = sys_mount("devtmpfs", "/", "devtmpfs", MS_SILENT, options); + if (*err) + goto out; + sys_chdir("/.."); /* will traverse into overmounted root */ + sys_chroot("."); + complete(&setup_done); + while (1) { + spin_lock(&req_lock); + while (requests) { + struct req *req = requests; + requests = NULL; + spin_unlock(&req_lock); + while (req) { + struct req *next = req->next; + req->err = handle(req->name, req->mode, + req->uid, req->gid, req->dev); + complete(&req->done); + req = next; + } + spin_lock(&req_lock); + } + __set_current_state(TASK_INTERRUPTIBLE); + spin_unlock(&req_lock); + schedule(); + } + return 0; +out: + complete(&setup_done); + return *err; +} + +/* + * Create devtmpfs instance, driver-core devices will add their device + * nodes here. + */ +int __init devtmpfs_init(void) +{ + int err = register_filesystem(&dev_fs_type); + if (err) { + printk(KERN_ERR "devtmpfs: unable to register devtmpfs " + "type %i\n", err); + return err; + } + + thread = kthread_run(devtmpfsd, &err, "kdevtmpfs"); + if (!IS_ERR(thread)) { + wait_for_completion(&setup_done); + } else { + err = PTR_ERR(thread); + thread = NULL; + } + + if (err) { + printk(KERN_ERR "devtmpfs: unable to create devtmpfs %i\n", err); + unregister_filesystem(&dev_fs_type); + return err; + } + + printk(KERN_INFO "devtmpfs: initialized\n"); + return 0; +} diff --git a/fs/posix_acl.c b/fs/posix_acl.c new file mode 100644 index 0000000..0855f77 --- /dev/null +++ b/fs/posix_acl.c @@ -0,0 +1,901 @@ +/* + * Copyright (C) 2002,2003 by Andreas Gruenbacher + * + * Fixes from William Schumacher incorporated on 15 March 2001. + * (Reported by Charles Bertsch, ). + */ + +/* + * This file contains generic functions for manipulating + * POSIX 1003.1e draft standard 17 ACLs. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct posix_acl **acl_by_type(struct inode *inode, int type) +{ + switch (type) { + case ACL_TYPE_ACCESS: + return &inode->i_acl; + case ACL_TYPE_DEFAULT: + return &inode->i_default_acl; + default: + BUG(); + } +} +EXPORT_SYMBOL(acl_by_type); + +struct posix_acl *get_cached_acl(struct inode *inode, int type) +{ + struct posix_acl **p = acl_by_type(inode, type); + struct posix_acl *acl = ACCESS_ONCE(*p); + if (acl) { + spin_lock(&inode->i_lock); + acl = *p; + if (acl != ACL_NOT_CACHED) + acl = posix_acl_dup(acl); + spin_unlock(&inode->i_lock); + } + return acl; +} +EXPORT_SYMBOL(get_cached_acl); + +struct posix_acl *get_cached_acl_rcu(struct inode *inode, int type) +{ + return rcu_dereference(*acl_by_type(inode, type)); +} +EXPORT_SYMBOL(get_cached_acl_rcu); + +void set_cached_acl(struct inode *inode, int type, struct posix_acl *acl) +{ + struct posix_acl **p = acl_by_type(inode, type); + struct posix_acl *old; + spin_lock(&inode->i_lock); + old = *p; + rcu_assign_pointer(*p, posix_acl_dup(acl)); + spin_unlock(&inode->i_lock); + if (old != ACL_NOT_CACHED) + posix_acl_release(old); +} +EXPORT_SYMBOL(set_cached_acl); + +void forget_cached_acl(struct inode *inode, int type) +{ + struct posix_acl **p = acl_by_type(inode, type); + struct posix_acl *old; + spin_lock(&inode->i_lock); + old = *p; + *p = ACL_NOT_CACHED; + spin_unlock(&inode->i_lock); + if (old != ACL_NOT_CACHED) + posix_acl_release(old); +} +EXPORT_SYMBOL(forget_cached_acl); + +void forget_all_cached_acls(struct inode *inode) +{ + struct posix_acl *old_access, *old_default; + spin_lock(&inode->i_lock); + old_access = inode->i_acl; + old_default = inode->i_default_acl; + inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED; + spin_unlock(&inode->i_lock); + if (old_access != ACL_NOT_CACHED) + posix_acl_release(old_access); + if (old_default != ACL_NOT_CACHED) + posix_acl_release(old_default); +} +EXPORT_SYMBOL(forget_all_cached_acls); + +struct posix_acl *get_acl(struct inode *inode, int type) +{ + struct posix_acl *acl; + + acl = get_cached_acl(inode, type); + if (acl != ACL_NOT_CACHED) + return acl; + + if (!IS_POSIXACL(inode)) + return NULL; + + /* + * A filesystem can force a ACL callback by just never filling the + * ACL cache. But normally you'd fill the cache either at inode + * instantiation time, or on the first ->get_acl call. + * + * If the filesystem doesn't have a get_acl() function at all, we'll + * just create the negative cache entry. + */ + if (!inode->i_op->get_acl) { + set_cached_acl(inode, type, NULL); + return NULL; + } + return inode->i_op->get_acl(inode, type); +} +EXPORT_SYMBOL(get_acl); + +/* + * Init a fresh posix_acl + */ +void +posix_acl_init(struct posix_acl *acl, int count) +{ + atomic_set(&acl->a_refcount, 1); + acl->a_count = count; +} +EXPORT_SYMBOL(posix_acl_init); + +/* + * Allocate a new ACL with the specified number of entries. + */ +struct posix_acl * +posix_acl_alloc(int count, gfp_t flags) +{ + const size_t size = sizeof(struct posix_acl) + + count * sizeof(struct posix_acl_entry); + struct posix_acl *acl = kmalloc(size, flags); + if (acl) + posix_acl_init(acl, count); + return acl; +} +EXPORT_SYMBOL(posix_acl_alloc); + +/* + * Clone an ACL. + */ +static struct posix_acl * +posix_acl_clone(const struct posix_acl *acl, gfp_t flags) +{ + struct posix_acl *clone = NULL; + + if (acl) { + int size = sizeof(struct posix_acl) + acl->a_count * + sizeof(struct posix_acl_entry); + clone = kmemdup(acl, size, flags); + if (clone) + atomic_set(&clone->a_refcount, 1); + } + return clone; +} + +/* + * Check if an acl is valid. Returns 0 if it is, or -E... otherwise. + */ +int +posix_acl_valid(const struct posix_acl *acl) +{ + const struct posix_acl_entry *pa, *pe; + int state = ACL_USER_OBJ; + int needs_mask = 0; + + FOREACH_ACL_ENTRY(pa, acl, pe) { + if (pa->e_perm & ~(ACL_READ|ACL_WRITE|ACL_EXECUTE)) + return -EINVAL; + switch (pa->e_tag) { + case ACL_USER_OBJ: + if (state == ACL_USER_OBJ) { + state = ACL_USER; + break; + } + return -EINVAL; + + case ACL_USER: + if (state != ACL_USER) + return -EINVAL; + if (!uid_valid(pa->e_uid)) + return -EINVAL; + needs_mask = 1; + break; + + case ACL_GROUP_OBJ: + if (state == ACL_USER) { + state = ACL_GROUP; + break; + } + return -EINVAL; + + case ACL_GROUP: + if (state != ACL_GROUP) + return -EINVAL; + if (!gid_valid(pa->e_gid)) + return -EINVAL; + needs_mask = 1; + break; + + case ACL_MASK: + if (state != ACL_GROUP) + return -EINVAL; + state = ACL_OTHER; + break; + + case ACL_OTHER: + if (state == ACL_OTHER || + (state == ACL_GROUP && !needs_mask)) { + state = 0; + break; + } + return -EINVAL; + + default: + return -EINVAL; + } + } + if (state == 0) + return 0; + return -EINVAL; +} +EXPORT_SYMBOL(posix_acl_valid); + +/* + * Returns 0 if the acl can be exactly represented in the traditional + * file mode permission bits, or else 1. Returns -E... on error. + */ +int +posix_acl_equiv_mode(const struct posix_acl *acl, umode_t *mode_p) +{ + const struct posix_acl_entry *pa, *pe; + umode_t mode = 0; + int not_equiv = 0; + + /* + * A null ACL can always be presented as mode bits. + */ + if (!acl) + return 0; + + FOREACH_ACL_ENTRY(pa, acl, pe) { + switch (pa->e_tag) { + case ACL_USER_OBJ: + mode |= (pa->e_perm & S_IRWXO) << 6; + break; + case ACL_GROUP_OBJ: + mode |= (pa->e_perm & S_IRWXO) << 3; + break; + case ACL_OTHER: + mode |= pa->e_perm & S_IRWXO; + break; + case ACL_MASK: + mode = (mode & ~S_IRWXG) | + ((pa->e_perm & S_IRWXO) << 3); + not_equiv = 1; + break; + case ACL_USER: + case ACL_GROUP: + not_equiv = 1; + break; + default: + return -EINVAL; + } + } + if (mode_p) + *mode_p = (*mode_p & ~S_IRWXUGO) | mode; + return not_equiv; +} +EXPORT_SYMBOL(posix_acl_equiv_mode); + +/* + * Create an ACL representing the file mode permission bits of an inode. + */ +struct posix_acl * +posix_acl_from_mode(umode_t mode, gfp_t flags) +{ + struct posix_acl *acl = posix_acl_alloc(3, flags); + if (!acl) + return ERR_PTR(-ENOMEM); + + acl->a_entries[0].e_tag = ACL_USER_OBJ; + acl->a_entries[0].e_perm = (mode & S_IRWXU) >> 6; + + acl->a_entries[1].e_tag = ACL_GROUP_OBJ; + acl->a_entries[1].e_perm = (mode & S_IRWXG) >> 3; + + acl->a_entries[2].e_tag = ACL_OTHER; + acl->a_entries[2].e_perm = (mode & S_IRWXO); + return acl; +} +EXPORT_SYMBOL(posix_acl_from_mode); + +/* + * Return 0 if current is granted want access to the inode + * by the acl. Returns -E... otherwise. + */ +int +posix_acl_permission(struct inode *inode, const struct posix_acl *acl, int want) +{ + const struct posix_acl_entry *pa, *pe, *mask_obj; + int found = 0; + + want &= MAY_READ | MAY_WRITE | MAY_EXEC | MAY_NOT_BLOCK; + + FOREACH_ACL_ENTRY(pa, acl, pe) { + switch(pa->e_tag) { + case ACL_USER_OBJ: + /* (May have been checked already) */ + if (uid_eq(inode->i_uid, current_fsuid())) + goto check_perm; + break; + case ACL_USER: + if (uid_eq(pa->e_uid, current_fsuid())) + goto mask; + break; + case ACL_GROUP_OBJ: + if (in_group_p(inode->i_gid)) { + found = 1; + if ((pa->e_perm & want) == want) + goto mask; + } + break; + case ACL_GROUP: + if (in_group_p(pa->e_gid)) { + found = 1; + if ((pa->e_perm & want) == want) + goto mask; + } + break; + case ACL_MASK: + break; + case ACL_OTHER: + if (found) + return -EACCES; + else + goto check_perm; + default: + return -EIO; + } + } + return -EIO; + +mask: + for (mask_obj = pa+1; mask_obj != pe; mask_obj++) { + if (mask_obj->e_tag == ACL_MASK) { + if ((pa->e_perm & mask_obj->e_perm & want) == want) + return 0; + return -EACCES; + } + } + +check_perm: + if ((pa->e_perm & want) == want) + return 0; + return -EACCES; +} + +/* + * Modify acl when creating a new inode. The caller must ensure the acl is + * only referenced once. + * + * mode_p initially must contain the mode parameter to the open() / creat() + * system calls. All permissions that are not granted by the acl are removed. + * The permissions in the acl are changed to reflect the mode_p parameter. + */ +static int posix_acl_create_masq(struct posix_acl *acl, umode_t *mode_p) +{ + struct posix_acl_entry *pa, *pe; + struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; + umode_t mode = *mode_p; + int not_equiv = 0; + + /* assert(atomic_read(acl->a_refcount) == 1); */ + + FOREACH_ACL_ENTRY(pa, acl, pe) { + switch(pa->e_tag) { + case ACL_USER_OBJ: + pa->e_perm &= (mode >> 6) | ~S_IRWXO; + mode &= (pa->e_perm << 6) | ~S_IRWXU; + break; + + case ACL_USER: + case ACL_GROUP: + not_equiv = 1; + break; + + case ACL_GROUP_OBJ: + group_obj = pa; + break; + + case ACL_OTHER: + pa->e_perm &= mode | ~S_IRWXO; + mode &= pa->e_perm | ~S_IRWXO; + break; + + case ACL_MASK: + mask_obj = pa; + not_equiv = 1; + break; + + default: + return -EIO; + } + } + + if (mask_obj) { + mask_obj->e_perm &= (mode >> 3) | ~S_IRWXO; + mode &= (mask_obj->e_perm << 3) | ~S_IRWXG; + } else { + if (!group_obj) + return -EIO; + group_obj->e_perm &= (mode >> 3) | ~S_IRWXO; + mode &= (group_obj->e_perm << 3) | ~S_IRWXG; + } + + *mode_p = (*mode_p & ~S_IRWXUGO) | mode; + return not_equiv; +} + +/* + * Modify the ACL for the chmod syscall. + */ +static int __posix_acl_chmod_masq(struct posix_acl *acl, umode_t mode) +{ + struct posix_acl_entry *group_obj = NULL, *mask_obj = NULL; + struct posix_acl_entry *pa, *pe; + + /* assert(atomic_read(acl->a_refcount) == 1); */ + + FOREACH_ACL_ENTRY(pa, acl, pe) { + switch(pa->e_tag) { + case ACL_USER_OBJ: + pa->e_perm = (mode & S_IRWXU) >> 6; + break; + + case ACL_USER: + case ACL_GROUP: + break; + + case ACL_GROUP_OBJ: + group_obj = pa; + break; + + case ACL_MASK: + mask_obj = pa; + break; + + case ACL_OTHER: + pa->e_perm = (mode & S_IRWXO); + break; + + default: + return -EIO; + } + } + + if (mask_obj) { + mask_obj->e_perm = (mode & S_IRWXG) >> 3; + } else { + if (!group_obj) + return -EIO; + group_obj->e_perm = (mode & S_IRWXG) >> 3; + } + + return 0; +} + +int +__posix_acl_create(struct posix_acl **acl, gfp_t gfp, umode_t *mode_p) +{ + struct posix_acl *clone = posix_acl_clone(*acl, gfp); + int err = -ENOMEM; + if (clone) { + err = posix_acl_create_masq(clone, mode_p); + if (err < 0) { + posix_acl_release(clone); + clone = NULL; + } + } + posix_acl_release(*acl); + *acl = clone; + return err; +} +EXPORT_SYMBOL(__posix_acl_create); + +int +__posix_acl_chmod(struct posix_acl **acl, gfp_t gfp, umode_t mode) +{ + struct posix_acl *clone = posix_acl_clone(*acl, gfp); + int err = -ENOMEM; + if (clone) { + err = __posix_acl_chmod_masq(clone, mode); + if (err) { + posix_acl_release(clone); + clone = NULL; + } + } + posix_acl_release(*acl); + *acl = clone; + return err; +} +EXPORT_SYMBOL(__posix_acl_chmod); + +int +posix_acl_chmod(struct inode *inode, umode_t mode) +{ + struct posix_acl *acl; + int ret = 0; + + if (!IS_POSIXACL(inode)) + return 0; + if (!inode->i_op->set_acl) + return -EOPNOTSUPP; + + acl = get_acl(inode, ACL_TYPE_ACCESS); + if (IS_ERR_OR_NULL(acl)) { + if (acl == ERR_PTR(-EOPNOTSUPP)) + return 0; + return PTR_ERR(acl); + } + + ret = __posix_acl_chmod(&acl, GFP_KERNEL, mode); + if (ret) + return ret; + ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS); + posix_acl_release(acl); + return ret; +} +EXPORT_SYMBOL(posix_acl_chmod); + +int +posix_acl_create(struct inode *dir, umode_t *mode, + struct posix_acl **default_acl, struct posix_acl **acl) +{ + struct posix_acl *p; + int ret; + + if (S_ISLNK(*mode) || !IS_POSIXACL(dir)) + goto no_acl; + + p = get_acl(dir, ACL_TYPE_DEFAULT); + if (IS_ERR(p)) { + if (p == ERR_PTR(-EOPNOTSUPP)) + goto apply_umask; + return PTR_ERR(p); + } + + if (!p) + goto apply_umask; + + *acl = posix_acl_clone(p, GFP_NOFS); + if (!*acl) + return -ENOMEM; + + ret = posix_acl_create_masq(*acl, mode); + if (ret < 0) { + posix_acl_release(*acl); + return -ENOMEM; + } + + if (ret == 0) { + posix_acl_release(*acl); + *acl = NULL; + } + + if (!S_ISDIR(*mode)) { + posix_acl_release(p); + *default_acl = NULL; + } else { + *default_acl = p; + } + return 0; + +apply_umask: + *mode &= ~current_umask(); +no_acl: + *default_acl = NULL; + *acl = NULL; + return 0; +} +EXPORT_SYMBOL_GPL(posix_acl_create); + +/* + * Fix up the uids and gids in posix acl extended attributes in place. + */ +static void posix_acl_fix_xattr_userns( + struct user_namespace *to, struct user_namespace *from, + void *value, size_t size) +{ + posix_acl_xattr_header *header = (posix_acl_xattr_header *)value; + posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end; + int count; + kuid_t uid; + kgid_t gid; + + if (!value) + return; + if (size < sizeof(posix_acl_xattr_header)) + return; + if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION)) + return; + + count = posix_acl_xattr_count(size); + if (count < 0) + return; + if (count == 0) + return; + + for (end = entry + count; entry != end; entry++) { + switch(le16_to_cpu(entry->e_tag)) { + case ACL_USER: + uid = make_kuid(from, le32_to_cpu(entry->e_id)); + entry->e_id = cpu_to_le32(from_kuid(to, uid)); + break; + case ACL_GROUP: + gid = make_kgid(from, le32_to_cpu(entry->e_id)); + entry->e_id = cpu_to_le32(from_kgid(to, gid)); + break; + default: + break; + } + } +} + +void posix_acl_fix_xattr_from_user(void *value, size_t size) +{ + struct user_namespace *user_ns = current_user_ns(); + if (user_ns == &init_user_ns) + return; + posix_acl_fix_xattr_userns(&init_user_ns, user_ns, value, size); +} + +void posix_acl_fix_xattr_to_user(void *value, size_t size) +{ + struct user_namespace *user_ns = current_user_ns(); + if (user_ns == &init_user_ns) + return; + posix_acl_fix_xattr_userns(user_ns, &init_user_ns, value, size); +} + +/* + * Convert from extended attribute to in-memory representation. + */ +struct posix_acl * +posix_acl_from_xattr(struct user_namespace *user_ns, + const void *value, size_t size) +{ + posix_acl_xattr_header *header = (posix_acl_xattr_header *)value; + posix_acl_xattr_entry *entry = (posix_acl_xattr_entry *)(header+1), *end; + int count; + struct posix_acl *acl; + struct posix_acl_entry *acl_e; + + if (!value) + return NULL; + if (size < sizeof(posix_acl_xattr_header)) + return ERR_PTR(-EINVAL); + if (header->a_version != cpu_to_le32(POSIX_ACL_XATTR_VERSION)) + return ERR_PTR(-EOPNOTSUPP); + + count = posix_acl_xattr_count(size); + if (count < 0) + return ERR_PTR(-EINVAL); + if (count == 0) + return NULL; + + acl = posix_acl_alloc(count, GFP_NOFS); + if (!acl) + return ERR_PTR(-ENOMEM); + acl_e = acl->a_entries; + + for (end = entry + count; entry != end; acl_e++, entry++) { + acl_e->e_tag = le16_to_cpu(entry->e_tag); + acl_e->e_perm = le16_to_cpu(entry->e_perm); + + switch(acl_e->e_tag) { + case ACL_USER_OBJ: + case ACL_GROUP_OBJ: + case ACL_MASK: + case ACL_OTHER: + break; + + case ACL_USER: + acl_e->e_uid = + make_kuid(user_ns, + le32_to_cpu(entry->e_id)); + if (!uid_valid(acl_e->e_uid)) + goto fail; + break; + case ACL_GROUP: + acl_e->e_gid = + make_kgid(user_ns, + le32_to_cpu(entry->e_id)); + if (!gid_valid(acl_e->e_gid)) + goto fail; + break; + + default: + goto fail; + } + } + return acl; + +fail: + posix_acl_release(acl); + return ERR_PTR(-EINVAL); +} +EXPORT_SYMBOL (posix_acl_from_xattr); + +/* + * Convert from in-memory to extended attribute representation. + */ +int +posix_acl_to_xattr(struct user_namespace *user_ns, const struct posix_acl *acl, + void *buffer, size_t size) +{ + posix_acl_xattr_header *ext_acl = (posix_acl_xattr_header *)buffer; + posix_acl_xattr_entry *ext_entry; + int real_size, n; + + real_size = posix_acl_xattr_size(acl->a_count); + if (!buffer) + return real_size; + if (real_size > size) + return -ERANGE; + + ext_entry = ext_acl->a_entries; + ext_acl->a_version = cpu_to_le32(POSIX_ACL_XATTR_VERSION); + + for (n=0; n < acl->a_count; n++, ext_entry++) { + const struct posix_acl_entry *acl_e = &acl->a_entries[n]; + ext_entry->e_tag = cpu_to_le16(acl_e->e_tag); + ext_entry->e_perm = cpu_to_le16(acl_e->e_perm); + switch(acl_e->e_tag) { + case ACL_USER: + ext_entry->e_id = + cpu_to_le32(from_kuid(user_ns, acl_e->e_uid)); + break; + case ACL_GROUP: + ext_entry->e_id = + cpu_to_le32(from_kgid(user_ns, acl_e->e_gid)); + break; + default: + ext_entry->e_id = cpu_to_le32(ACL_UNDEFINED_ID); + break; + } + } + return real_size; +} +EXPORT_SYMBOL (posix_acl_to_xattr); + +static int +posix_acl_xattr_get(struct dentry *dentry, const char *name, + void *value, size_t size, int type) +{ + struct posix_acl *acl; + int error; + + if (!IS_POSIXACL(dentry->d_inode)) + return -EOPNOTSUPP; + if (S_ISLNK(dentry->d_inode->i_mode)) + return -EOPNOTSUPP; + + acl = get_acl(dentry->d_inode, type); + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl == NULL) + return -ENODATA; + + error = posix_acl_to_xattr(&init_user_ns, acl, value, size); + posix_acl_release(acl); + + return error; +} + +static int +posix_acl_xattr_set(struct dentry *dentry, const char *name, + const void *value, size_t size, int flags, int type) +{ + struct inode *inode = dentry->d_inode; + struct posix_acl *acl = NULL; + int ret; + + if (!IS_POSIXACL(inode)) + return -EOPNOTSUPP; + if (!inode->i_op->set_acl) + return -EOPNOTSUPP; + + if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode)) + return value ? -EACCES : 0; + if (!inode_owner_or_capable(inode)) + return -EPERM; + + if (value) { + acl = posix_acl_from_xattr(&init_user_ns, value, size); + if (IS_ERR(acl)) + return PTR_ERR(acl); + + if (acl) { + ret = posix_acl_valid(acl); + if (ret) + goto out; + } + } + + ret = inode->i_op->set_acl(inode, acl, type); +out: + posix_acl_release(acl); + return ret; +} + +static size_t +posix_acl_xattr_list(struct dentry *dentry, char *list, size_t list_size, + const char *name, size_t name_len, int type) +{ + const char *xname; + size_t size; + + if (!IS_POSIXACL(dentry->d_inode)) + return -EOPNOTSUPP; + if (S_ISLNK(dentry->d_inode->i_mode)) + return -EOPNOTSUPP; + + if (type == ACL_TYPE_ACCESS) + xname = POSIX_ACL_XATTR_ACCESS; + else + xname = POSIX_ACL_XATTR_DEFAULT; + + size = strlen(xname) + 1; + if (list && size <= list_size) + memcpy(list, xname, size); + return size; +} + +const struct xattr_handler posix_acl_access_xattr_handler = { + .prefix = POSIX_ACL_XATTR_ACCESS, + .flags = ACL_TYPE_ACCESS, + .list = posix_acl_xattr_list, + .get = posix_acl_xattr_get, + .set = posix_acl_xattr_set, +}; +EXPORT_SYMBOL_GPL(posix_acl_access_xattr_handler); + +const struct xattr_handler posix_acl_default_xattr_handler = { + .prefix = POSIX_ACL_XATTR_DEFAULT, + .flags = ACL_TYPE_DEFAULT, + .list = posix_acl_xattr_list, + .get = posix_acl_xattr_get, + .set = posix_acl_xattr_set, +}; +EXPORT_SYMBOL_GPL(posix_acl_default_xattr_handler); + +int simple_set_acl(struct inode *inode, struct posix_acl *acl, int type) +{ + int error; + + if (type == ACL_TYPE_ACCESS) { + error = posix_acl_equiv_mode(acl, &inode->i_mode); + if (error < 0) + return 0; + if (error == 0) + acl = NULL; + } + + inode->i_ctime = CURRENT_TIME; + set_cached_acl(inode, type, acl); + return 0; +} + +int simple_acl_create(struct inode *dir, struct inode *inode) +{ + struct posix_acl *default_acl, *acl; + int error; + + error = posix_acl_create(dir, &inode->i_mode, &default_acl, &acl); + if (error) + return error; + + set_cached_acl(inode, ACL_TYPE_DEFAULT, default_acl); + set_cached_acl(inode, ACL_TYPE_ACCESS, acl); + + if (default_acl) + posix_acl_release(default_acl); + if (acl) + posix_acl_release(acl); + return 0; +}