X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fnamei.c;h=bbc15c237558f82c7fbe2b661e55ee8fa1b9849d;hb=7ef0d7377cb287e08f3ae94cebc919448e1f5dff;hp=89ef3178eaaa48660ed487c9e5c67926ef175df8;hpb=0622753b800e4cc6cb9319b36b27658c72dd7cdc;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/namei.c b/fs/namei.c index 89ef317..bbc15c2 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -30,7 +30,7 @@ #include #include #include -#include +#include #include #define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE]) @@ -184,7 +184,9 @@ int generic_permission(struct inode *inode, int mask, { umode_t mode = inode->i_mode; - if (current->fsuid == inode->i_uid) + mask &= MAY_READ | MAY_WRITE | MAY_EXEC; + + if (current_fsuid() == inode->i_uid) mode >>= 6; else { if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) { @@ -202,7 +204,7 @@ int generic_permission(struct inode *inode, int mask, /* * If the DACs are ok we don't need any capability check. */ - if (((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask)) + if ((mask & ~mode) == 0) return 0; check_capabilities: @@ -210,8 +212,7 @@ int generic_permission(struct inode *inode, int mask, * Read/write DACs are always overridable. * Executable DACs are overridable if at least one exec bit is set. */ - if (!(mask & MAY_EXEC) || - (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode)) + if (!(mask & MAY_EXEC) || execute_ok(inode)) if (capable(CAP_DAC_OVERRIDE)) return 0; @@ -225,13 +226,19 @@ int generic_permission(struct inode *inode, int mask, return -EACCES; } -int permission(struct inode *inode, int mask, struct nameidata *nd) +/** + * inode_permission - check for access rights to a given inode + * @inode: inode to check permission on + * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) + * + * Used to check for read/write/execute permissions on an inode. + * We use "fsuid" for this, letting us set arbitrary permissions + * for filesystem access without changing the "normal" uids which + * are used for other things. + */ +int inode_permission(struct inode *inode, int mask) { - int retval, submask; - struct vfsmount *mnt = NULL; - - if (nd) - mnt = nd->path.mnt; + int retval; if (mask & MAY_WRITE) { umode_t mode = inode->i_mode; @@ -250,53 +257,20 @@ int permission(struct inode *inode, int mask, struct nameidata *nd) return -EACCES; } - if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) { - /* - * MAY_EXEC on regular files is denied if the fs is mounted - * with the "noexec" flag. - */ - if (mnt && (mnt->mnt_flags & MNT_NOEXEC)) - return -EACCES; - } + if (inode->i_op->permission) + retval = inode->i_op->permission(inode, mask); + else + retval = generic_permission(inode, mask, NULL); - /* Ordinary permission routines do not understand MAY_APPEND. */ - submask = mask & ~MAY_APPEND; - if (inode->i_op && inode->i_op->permission) { - retval = inode->i_op->permission(inode, submask, nd); - if (!retval) { - /* - * Exec permission on a regular file is denied if none - * of the execute bits are set. - * - * This check should be done by the ->permission() - * method. - */ - if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode) && - !(inode->i_mode & S_IXUGO)) - return -EACCES; - } - } else { - retval = generic_permission(inode, submask, NULL); - } if (retval) return retval; - return security_inode_permission(inode, mask, nd); -} + retval = devcgroup_inode_permission(inode, mask); + if (retval) + return retval; -/** - * vfs_permission - check for access rights to a given path - * @nd: lookup result that describes the path - * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) - * - * Used to check for read/write/execute permissions on a path. - * We use "fsuid" for this, letting us set arbitrary permissions - * for filesystem access without changing the "normal" uids which - * are used for other things. - */ -int vfs_permission(struct nameidata *nd, int mask) -{ - return permission(nd->path.dentry->d_inode, mask, nd); + return security_inode_permission(inode, + mask & (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND)); } /** @@ -309,11 +283,11 @@ int vfs_permission(struct nameidata *nd, int mask) * * Note: * Do not use this function in new code. All access checks should - * be done using vfs_permission(). + * be done using inode_permission(). */ int file_permission(struct file *file, int mask) { - return permission(file->f_path.dentry->d_inode, mask, NULL); + return inode_permission(file->f_path.dentry->d_inode, mask); } /* @@ -454,15 +428,14 @@ static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name, * short-cut DAC fails, then call permission() to do more * complete permission check. */ -static int exec_permission_lite(struct inode *inode, - struct nameidata *nd) +static int exec_permission_lite(struct inode *inode) { umode_t mode = inode->i_mode; - if (inode->i_op && inode->i_op->permission) + if (inode->i_op->permission) return -EAGAIN; - if (current->fsuid == inode->i_uid) + if (current_fsuid() == inode->i_uid) mode >>= 6; else if (in_group_p(inode->i_gid)) mode >>= 3; @@ -481,7 +454,7 @@ static int exec_permission_lite(struct inode *inode, return -EACCES; ok: - return security_inode_permission(inode, MAY_EXEC, nd); + return security_inode_permission(inode, MAY_EXEC); } /* @@ -514,7 +487,14 @@ static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, s */ result = d_lookup(parent, name); if (!result) { - struct dentry * dentry = d_alloc(parent, name); + struct dentry *dentry; + + /* Don't create child dentry for a dead directory. */ + result = ERR_PTR(-ENOENT); + if (IS_DEADDIR(dir)) + goto out_unlock; + + dentry = d_alloc(parent, name); result = ERR_PTR(-ENOMEM); if (dentry) { result = dir->i_op->lookup(dir, dentry, nd); @@ -523,6 +503,7 @@ static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, s else result = dentry; } +out_unlock: mutex_unlock(&dir->i_mutex); return result; } @@ -540,29 +521,6 @@ static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, s return result; } -static int __emul_lookup_dentry(const char *, struct nameidata *); - -/* SMP-safe */ -static __always_inline int -walk_init_root(const char *name, struct nameidata *nd) -{ - struct fs_struct *fs = current->fs; - - read_lock(&fs->lock); - if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) { - nd->path = fs->altroot; - path_get(&fs->altroot); - read_unlock(&fs->lock); - if (__emul_lookup_dentry(name,nd)) - return 0; - read_lock(&fs->lock); - } - nd->path = fs->root; - path_get(&fs->root); - read_unlock(&fs->lock); - return 1; -} - /* * Wrapper to retry pathname resolution whenever the underlying * file system returns an ESTALE. @@ -576,15 +534,13 @@ static __always_inline int link_path_walk(const char *name, struct nameidata *nd int result; /* make sure the stuff we saved doesn't go away */ - dget(save.dentry); - mntget(save.mnt); + path_get(&save); result = __link_path_walk(name, nd); if (result == -ESTALE) { /* nd->path had been dropped */ nd->path = save; - dget(nd->path.dentry); - mntget(nd->path.mnt); + path_get(&nd->path); nd->flags |= LOOKUP_REVAL; result = __link_path_walk(name, nd); } @@ -602,13 +558,17 @@ static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *l goto fail; if (*link == '/') { + struct fs_struct *fs = current->fs; + path_put(&nd->path); - if (!walk_init_root(link, nd)) - /* weird __emul_prefix() stuff did it */ - goto out; + + read_lock(&fs->lock); + nd->path = fs->root; + path_get(&fs->root); + read_unlock(&fs->lock); } + res = link_path_walk(link, nd); -out: if (nd->depth || res || nd->last_type!=LAST_NORM) return res; /* @@ -886,9 +846,10 @@ static int __link_path_walk(const char *name, struct nameidata *nd) unsigned int c; nd->flags |= LOOKUP_CONTINUE; - err = exec_permission_lite(inode, nd); + err = exec_permission_lite(inode); if (err == -EAGAIN) - err = vfs_permission(nd, MAY_EXEC); + err = inode_permission(nd->path.dentry->d_inode, + MAY_EXEC); if (err) break; @@ -947,9 +908,6 @@ static int __link_path_walk(const char *name, struct nameidata *nd) inode = next.dentry->d_inode; if (!inode) goto out_dput; - err = -ENOTDIR; - if (!inode->i_op) - goto out_dput; if (inode->i_op->follow_link) { err = do_follow_link(&next, nd); @@ -959,9 +917,6 @@ static int __link_path_walk(const char *name, struct nameidata *nd) inode = nd->path.dentry->d_inode; if (!inode) break; - err = -ENOTDIR; - if (!inode->i_op) - break; } else path_to_nameidata(&next, nd); err = -ENOTDIR; @@ -1000,7 +955,7 @@ last_component: break; inode = next.dentry->d_inode; if ((lookup_flags & LOOKUP_FOLLOW) - && inode && inode->i_op && inode->i_op->follow_link) { + && inode && inode->i_op->follow_link) { err = do_follow_link(&next, nd); if (err) goto return_err; @@ -1012,7 +967,7 @@ last_component: break; if (lookup_flags & LOOKUP_DIRECTORY) { err = -ENOTDIR; - if (!inode->i_op || !inode->i_op->lookup) + if (!inode->i_op->lookup) break; } goto return_base; @@ -1057,67 +1012,6 @@ static int path_walk(const char *name, struct nameidata *nd) return link_path_walk(name, nd); } -/* - * SMP-safe: Returns 1 and nd will have valid dentry and mnt, if - * everything is done. Returns 0 and drops input nd, if lookup failed; - */ -static int __emul_lookup_dentry(const char *name, struct nameidata *nd) -{ - if (path_walk(name, nd)) - return 0; /* something went wrong... */ - - if (!nd->path.dentry->d_inode || - S_ISDIR(nd->path.dentry->d_inode->i_mode)) { - struct path old_path = nd->path; - struct qstr last = nd->last; - int last_type = nd->last_type; - struct fs_struct *fs = current->fs; - - /* - * NAME was not found in alternate root or it's a directory. - * Try to find it in the normal root: - */ - nd->last_type = LAST_ROOT; - read_lock(&fs->lock); - nd->path = fs->root; - path_get(&fs->root); - read_unlock(&fs->lock); - if (path_walk(name, nd) == 0) { - if (nd->path.dentry->d_inode) { - path_put(&old_path); - return 1; - } - path_put(&nd->path); - } - nd->path = old_path; - nd->last = last; - nd->last_type = last_type; - } - return 1; -} - -void set_fs_altroot(void) -{ - char *emul = __emul_prefix(); - struct nameidata nd; - struct path path = {}, old_path; - int err; - struct fs_struct *fs = current->fs; - - if (!emul) - goto set_it; - err = path_lookup(emul, LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_NOALT, &nd); - if (!err) - path = nd.path; -set_it: - write_lock(&fs->lock); - old_path = fs->altroot; - fs->altroot = path; - write_unlock(&fs->lock); - if (old_path.dentry) - path_put(&old_path); -} - /* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ static int do_path_lookup(int dfd, const char *name, unsigned int flags, struct nameidata *nd) @@ -1133,14 +1027,6 @@ static int do_path_lookup(int dfd, const char *name, if (*name=='/') { read_lock(&fs->lock); - if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) { - nd->path = fs->altroot; - path_get(&fs->altroot); - read_unlock(&fs->lock); - if (__emul_lookup_dentry(name,nd)) - goto out; /* found in altroot */ - read_lock(&fs->lock); - } nd->path = fs->root; path_get(&fs->root); read_unlock(&fs->lock); @@ -1174,7 +1060,6 @@ static int do_path_lookup(int dfd, const char *name, } retval = path_walk(name, nd); -out: if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && nd->path.dentry->d_inode)) audit_inode(name, nd->path.dentry); @@ -1192,6 +1077,15 @@ int path_lookup(const char *name, unsigned int flags, return do_path_lookup(AT_FDCWD, name, flags, nd); } +int kern_path(const char *name, unsigned int flags, struct path *path) +{ + struct nameidata nd; + int res = do_path_lookup(AT_FDCWD, name, flags, &nd); + if (!res) + *path = nd.path; + return res; +} + /** * vfs_path_lookup - lookup a file path relative to a dentry-vfsmount pair * @dentry: pointer to dentry of the base directory @@ -1211,8 +1105,9 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, nd->flags = flags; nd->depth = 0; - nd->path.mnt = mntget(mnt); - nd->path.dentry = dget(dentry); + nd->path.dentry = dentry; + nd->path.mnt = mnt; + path_get(&nd->path); retval = path_walk(name, nd); if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && @@ -1223,9 +1118,16 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, } -static int __path_lookup_intent_open(int dfd, const char *name, - unsigned int lookup_flags, struct nameidata *nd, - int open_flags, int create_mode) +/** + * path_lookup_open - lookup a file path with open intent + * @dfd: the directory to use as base, or AT_FDCWD + * @name: pointer to file name + * @lookup_flags: lookup intent flags + * @nd: pointer to nameidata + * @open_flags: open intent flags + */ +int path_lookup_open(int dfd, const char *name, unsigned int lookup_flags, + struct nameidata *nd, int open_flags) { struct file *filp = get_empty_filp(); int err; @@ -1234,7 +1136,7 @@ static int __path_lookup_intent_open(int dfd, const char *name, return -ENFILE; nd->intent.open.file = filp; nd->intent.open.flags = open_flags; - nd->intent.open.create_mode = create_mode; + nd->intent.open.create_mode = 0; err = do_path_lookup(dfd, name, lookup_flags|LOOKUP_OPEN, nd); if (IS_ERR(nd->intent.open.file)) { if (err == 0) { @@ -1246,51 +1148,6 @@ static int __path_lookup_intent_open(int dfd, const char *name, return err; } -/** - * path_lookup_open - lookup a file path with open intent - * @dfd: the directory to use as base, or AT_FDCWD - * @name: pointer to file name - * @lookup_flags: lookup intent flags - * @nd: pointer to nameidata - * @open_flags: open intent flags - */ -int path_lookup_open(int dfd, const char *name, unsigned int lookup_flags, - struct nameidata *nd, int open_flags) -{ - return __path_lookup_intent_open(dfd, name, lookup_flags, nd, - open_flags, 0); -} - -/** - * path_lookup_create - lookup a file path with open + create intent - * @dfd: the directory to use as base, or AT_FDCWD - * @name: pointer to file name - * @lookup_flags: lookup intent flags - * @nd: pointer to nameidata - * @open_flags: open intent flags - * @create_mode: create intent flags - */ -static int path_lookup_create(int dfd, const char *name, - unsigned int lookup_flags, struct nameidata *nd, - int open_flags, int create_mode) -{ - return __path_lookup_intent_open(dfd, name, lookup_flags|LOOKUP_CREATE, - nd, open_flags, create_mode); -} - -int __user_path_lookup_open(const char __user *name, unsigned int lookup_flags, - struct nameidata *nd, int open_flags) -{ - char *tmp = getname(name); - int err = PTR_ERR(tmp); - - if (!IS_ERR(tmp)) { - err = __path_lookup_intent_open(AT_FDCWD, tmp, lookup_flags, nd, open_flags, 0); - putname(tmp); - } - return err; -} - static struct dentry *__lookup_hash(struct qstr *name, struct dentry *base, struct nameidata *nd) { @@ -1313,7 +1170,14 @@ static struct dentry *__lookup_hash(struct qstr *name, dentry = cached_lookup(base, name, nd); if (!dentry) { - struct dentry *new = d_alloc(base, name); + struct dentry *new; + + /* Don't create child dentry for a dead directory. */ + dentry = ERR_PTR(-ENOENT); + if (IS_DEADDIR(inode)) + goto out; + + new = d_alloc(base, name); dentry = ERR_PTR(-ENOMEM); if (!new) goto out; @@ -1336,7 +1200,7 @@ static struct dentry *lookup_hash(struct nameidata *nd) { int err; - err = permission(nd->path.dentry->d_inode, MAY_EXEC, nd); + err = inode_permission(nd->path.dentry->d_inode, MAY_EXEC); if (err) return ERR_PTR(err); return __lookup_hash(&nd->last, nd->path.dentry, nd); @@ -1384,7 +1248,7 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) if (err) return ERR_PTR(err); - err = permission(base->d_inode, MAY_EXEC, NULL); + err = inode_permission(base->d_inode, MAY_EXEC); if (err) return ERR_PTR(err); return __lookup_hash(&this, base, NULL); @@ -1412,22 +1276,40 @@ struct dentry *lookup_one_noperm(const char *name, struct dentry *base) return __lookup_hash(&this, base, NULL); } -int __user_walk_fd(int dfd, const char __user *name, unsigned flags, - struct nameidata *nd) +int user_path_at(int dfd, const char __user *name, unsigned flags, + struct path *path) { + struct nameidata nd; char *tmp = getname(name); int err = PTR_ERR(tmp); - if (!IS_ERR(tmp)) { - err = do_path_lookup(dfd, tmp, flags, nd); + + BUG_ON(flags & LOOKUP_PARENT); + + err = do_path_lookup(dfd, tmp, flags, &nd); putname(tmp); + if (!err) + *path = nd.path; } return err; } -int __user_walk(const char __user *name, unsigned flags, struct nameidata *nd) +static int user_path_parent(int dfd, const char __user *path, + struct nameidata *nd, char **name) { - return __user_walk_fd(AT_FDCWD, name, flags, nd); + char *s = getname(path); + int error; + + if (IS_ERR(s)) + return PTR_ERR(s); + + error = do_path_lookup(dfd, s, LOOKUP_PARENT, nd); + if (error) + putname(s); + else + *name = s; + + return error; } /* @@ -1436,11 +1318,13 @@ int __user_walk(const char __user *name, unsigned flags, struct nameidata *nd) */ static inline int check_sticky(struct inode *dir, struct inode *inode) { + uid_t fsuid = current_fsuid(); + if (!(dir->i_mode & S_ISVTX)) return 0; - if (inode->i_uid == current->fsuid) + if (inode->i_uid == fsuid) return 0; - if (dir->i_uid == current->fsuid) + if (dir->i_uid == fsuid) return 0; return !capable(CAP_FOWNER); } @@ -1474,13 +1358,13 @@ static int may_delete(struct inode *dir,struct dentry *victim,int isdir) BUG_ON(victim->d_parent->d_inode != dir); audit_inode_child(victim->d_name.name, victim, dir); - error = permission(dir,MAY_WRITE | MAY_EXEC, NULL); + error = inode_permission(dir, MAY_WRITE | MAY_EXEC); if (error) return error; if (IS_APPEND(dir)) return -EPERM; if (check_sticky(dir, victim->d_inode)||IS_APPEND(victim->d_inode)|| - IS_IMMUTABLE(victim->d_inode)) + IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode)) return -EPERM; if (isdir) { if (!S_ISDIR(victim->d_inode->i_mode)) @@ -1504,14 +1388,13 @@ static int may_delete(struct inode *dir,struct dentry *victim,int isdir) * 3. We should have write and exec permissions on dir * 4. We can't do it if dir is immutable (done in permission()) */ -static inline int may_create(struct inode *dir, struct dentry *child, - struct nameidata *nd) +static inline int may_create(struct inode *dir, struct dentry *child) { if (child->d_inode) return -EEXIST; if (IS_DEADDIR(dir)) return -ENOENT; - return permission(dir,MAY_WRITE | MAY_EXEC, nd); + return inode_permission(dir, MAY_WRITE | MAY_EXEC); } /* @@ -1544,20 +1427,18 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2) mutex_lock(&p1->d_inode->i_sb->s_vfs_rename_mutex); - for (p = p1; p->d_parent != p; p = p->d_parent) { - if (p->d_parent == p2) { - mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD); - return p; - } + p = d_ancestor(p2, p1); + if (p) { + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD); + return p; } - for (p = p2; p->d_parent != p; p = p->d_parent) { - if (p->d_parent == p1) { - mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); - return p; - } + p = d_ancestor(p1, p2); + if (p) { + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); + return p; } mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); @@ -1577,12 +1458,12 @@ void unlock_rename(struct dentry *p1, struct dentry *p2) int vfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) { - int error = may_create(dir, dentry, nd); + int error = may_create(dir, dentry); if (error) return error; - if (!dir->i_op || !dir->i_op->create) + if (!dir->i_op->create) return -EACCES; /* shouldn't it be ENOSYS? */ mode &= S_IALLUGO; mode |= S_IFREG; @@ -1596,9 +1477,9 @@ int vfs_create(struct inode *dir, struct dentry *dentry, int mode, return error; } -int may_open(struct nameidata *nd, int acc_mode, int flag) +int may_open(struct path *path, int acc_mode, int flag) { - struct dentry *dentry = nd->path.dentry; + struct dentry *dentry = path->dentry; struct inode *inode = dentry->d_inode; int error; @@ -1619,14 +1500,13 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { flag &= ~O_TRUNC; } else if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) { - if (nd->path.mnt->mnt_flags & MNT_NODEV) + if (path->mnt->mnt_flags & MNT_NODEV) return -EACCES; flag &= ~O_TRUNC; - } else if (IS_RDONLY(inode) && (acc_mode & MAY_WRITE)) - return -EROFS; + } - error = vfs_permission(nd, acc_mode); + error = inode_permission(inode, acc_mode); if (error) return error; /* @@ -1660,6 +1540,9 @@ int may_open(struct nameidata *nd, int acc_mode, int flag) * Refuse to truncate files with mandatory locks held on them. */ error = locks_verify_locked(inode); + if (!error) + error = security_path_truncate(path, 0, + ATTR_MTIME|ATTR_CTIME|ATTR_OPEN); if (!error) { DQUOT_INIT(inode); @@ -1690,14 +1573,18 @@ static int __open_namei_create(struct nameidata *nd, struct path *path, if (!IS_POSIXACL(dir->d_inode)) mode &= ~current->fs->umask; + error = security_path_mknod(&nd->path, path->dentry, mode, 0); + if (error) + goto out_unlock; error = vfs_create(dir->d_inode, path->dentry, mode, nd); +out_unlock: mutex_unlock(&dir->d_inode->i_mutex); dput(nd->path.dentry); nd->path.dentry = path->dentry; if (error) return error; /* Don't check for write permission, don't truncate */ - return may_open(nd, 0, flag & ~O_TRUNC); + return may_open(&nd->path, 0, flag & ~O_TRUNC); } /* @@ -1724,21 +1611,35 @@ static inline int open_to_namei_flags(int flag) return flag; } +static int open_will_write_to_fs(int flag, struct inode *inode) +{ + /* + * We'll never write to the fs underlying + * a device file. + */ + if (special_file(inode->i_mode)) + return 0; + return (flag & O_TRUNC); +} + /* - * Note that the low bits of "flag" aren't the same as in the open - * system call. See open_to_namei_flags(). + * Note that the low bits of the passed in "open_flag" + * are not the same as in the local variable "flag". See + * open_to_namei_flags() for more details. */ struct file *do_filp_open(int dfd, const char *pathname, int open_flag, int mode) { + struct file *filp; struct nameidata nd; int acc_mode, error; struct path path; struct dentry *dir; int count = 0; + int will_write; int flag = open_to_namei_flags(open_flag); - acc_mode = ACC_MODE(flag); + acc_mode = MAY_OPEN | ACC_MODE(flag); /* O_TRUNC implies we need access checks for write permissions */ if (flag & O_TRUNC) @@ -1763,8 +1664,7 @@ struct file *do_filp_open(int dfd, const char *pathname, /* * Create - we need to know the parent. */ - error = path_lookup_create(dfd, pathname, LOOKUP_PARENT, - &nd, flag, mode); + error = do_path_lookup(dfd, pathname, LOOKUP_PARENT, &nd); if (error) return ERR_PTR(error); @@ -1775,10 +1675,20 @@ struct file *do_filp_open(int dfd, const char *pathname, */ error = -EISDIR; if (nd.last_type != LAST_NORM || nd.last.name[nd.last.len]) - goto exit; + goto exit_parent; + error = -ENFILE; + filp = get_empty_filp(); + if (filp == NULL) + goto exit_parent; + nd.intent.open.file = filp; + nd.intent.open.flags = flag; + nd.intent.open.create_mode = mode; dir = nd.path.dentry; nd.flags &= ~LOOKUP_PARENT; + nd.flags |= LOOKUP_CREATE | LOOKUP_OPEN; + if (flag & O_EXCL) + nd.flags |= LOOKUP_EXCL; mutex_lock(&dir->d_inode->i_mutex); path.dentry = lookup_hash(&nd); path.mnt = nd.path.mnt; @@ -1791,17 +1701,30 @@ do_last: } if (IS_ERR(nd.intent.open.file)) { - mutex_unlock(&dir->d_inode->i_mutex); error = PTR_ERR(nd.intent.open.file); - goto exit_dput; + goto exit_mutex_unlock; } /* Negative dentry, just create the file */ if (!path.dentry->d_inode) { - error = __open_namei_create(&nd, &path, flag, mode); + /* + * This write is needed to ensure that a + * ro->rw transition does not occur between + * the time when the file is created and when + * a permanent write count is taken through + * the 'struct file' in nameidata_to_filp(). + */ + error = mnt_want_write(nd.path.mnt); if (error) + goto exit_mutex_unlock; + error = __open_namei_create(&nd, &path, flag, mode); + if (error) { + mnt_drop_write(nd.path.mnt); goto exit; - return nameidata_to_filp(&nd, open_flag); + } + filp = nameidata_to_filp(&nd, open_flag); + mnt_drop_write(nd.path.mnt); + return filp; } /* @@ -1823,7 +1746,7 @@ do_last: error = -ENOENT; if (!path.dentry->d_inode) goto exit_dput; - if (path.dentry->d_inode->i_op && path.dentry->d_inode->i_op->follow_link) + if (path.dentry->d_inode->i_op->follow_link) goto do_link; path_to_nameidata(&path, &nd); @@ -1831,16 +1754,46 @@ do_last: if (path.dentry->d_inode && S_ISDIR(path.dentry->d_inode->i_mode)) goto exit; ok: - error = may_open(&nd, acc_mode, flag); - if (error) + /* + * Consider: + * 1. may_open() truncates a file + * 2. a rw->ro mount transition occurs + * 3. nameidata_to_filp() fails due to + * the ro mount. + * That would be inconsistent, and should + * be avoided. Taking this mnt write here + * ensures that (2) can not occur. + */ + will_write = open_will_write_to_fs(flag, nd.path.dentry->d_inode); + if (will_write) { + error = mnt_want_write(nd.path.mnt); + if (error) + goto exit; + } + error = may_open(&nd.path, acc_mode, flag); + if (error) { + if (will_write) + mnt_drop_write(nd.path.mnt); goto exit; - return nameidata_to_filp(&nd, open_flag); + } + filp = nameidata_to_filp(&nd, open_flag); + /* + * It is now safe to drop the mnt write + * because the filp has had a write taken + * on its behalf. + */ + if (will_write) + mnt_drop_write(nd.path.mnt); + return filp; +exit_mutex_unlock: + mutex_unlock(&dir->d_inode->i_mutex); exit_dput: path_put_conditional(&path, &nd); exit: if (!IS_ERR(nd.intent.open.file)) release_open_intent(&nd); +exit_parent: path_put(&nd.path); return ERR_PTR(error); @@ -1933,7 +1886,7 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir) if (nd->last_type != LAST_NORM) goto fail; nd->flags &= ~LOOKUP_PARENT; - nd->flags |= LOOKUP_CREATE; + nd->flags |= LOOKUP_CREATE | LOOKUP_EXCL; nd->intent.open.flags = O_EXCL; /* @@ -1943,18 +1896,22 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir) if (IS_ERR(dentry)) goto fail; + if (dentry->d_inode) + goto eexist; /* * Special case - lookup gave negative, but... we had foo/bar/ * From the vfs_mknod() POV we just have a negative dentry - * all is fine. Let's be bastards - you had / on the end, you've * been asking for (non-existent) directory. -ENOENT for you. */ - if (!is_dir && nd->last.name[nd->last.len] && !dentry->d_inode) - goto enoent; + if (unlikely(!is_dir && nd->last.name[nd->last.len])) { + dput(dentry); + dentry = ERR_PTR(-ENOENT); + } return dentry; -enoent: +eexist: dput(dentry); - dentry = ERR_PTR(-ENOENT); + dentry = ERR_PTR(-EEXIST); fail: return dentry; } @@ -1962,7 +1919,7 @@ EXPORT_SYMBOL_GPL(lookup_create); int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) { - int error = may_create(dir, dentry, NULL); + int error = may_create(dir, dentry); if (error) return error; @@ -1970,9 +1927,13 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD)) return -EPERM; - if (!dir->i_op || !dir->i_op->mknod) + if (!dir->i_op->mknod) return -EPERM; + error = devcgroup_inode_mknod(mode, dev); + if (error) + return error; + error = security_inode_mknod(dir, dentry, mode, dev); if (error) return error; @@ -1984,30 +1945,55 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) return error; } -asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode, - unsigned dev) +static int may_mknod(mode_t mode) { - int error = 0; - char * tmp; - struct dentry * dentry; + switch (mode & S_IFMT) { + case S_IFREG: + case S_IFCHR: + case S_IFBLK: + case S_IFIFO: + case S_IFSOCK: + case 0: /* zero mode translates to S_IFREG */ + return 0; + case S_IFDIR: + return -EPERM; + default: + return -EINVAL; + } +} + +SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, int, mode, + unsigned, dev) +{ + int error; + char *tmp; + struct dentry *dentry; struct nameidata nd; if (S_ISDIR(mode)) return -EPERM; - tmp = getname(filename); - if (IS_ERR(tmp)) - return PTR_ERR(tmp); - error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd); + error = user_path_parent(dfd, filename, &nd, &tmp); if (error) - goto out; - dentry = lookup_create(&nd, 0); - error = PTR_ERR(dentry); + return error; + dentry = lookup_create(&nd, 0); + if (IS_ERR(dentry)) { + error = PTR_ERR(dentry); + goto out_unlock; + } if (!IS_POSIXACL(nd.path.dentry->d_inode)) mode &= ~current->fs->umask; - if (!IS_ERR(dentry)) { - switch (mode & S_IFMT) { + error = may_mknod(mode); + if (error) + goto out_dput; + error = mnt_want_write(nd.path.mnt); + if (error) + goto out_dput; + error = security_path_mknod(&nd.path, dentry, mode, dev); + if (error) + goto out_drop_write; + switch (mode & S_IFMT) { case 0: case S_IFREG: error = vfs_create(nd.path.dentry->d_inode,dentry,mode,&nd); break; @@ -2018,35 +2004,32 @@ asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode, case S_IFIFO: case S_IFSOCK: error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,0); break; - case S_IFDIR: - error = -EPERM; - break; - default: - error = -EINVAL; - } - dput(dentry); } +out_drop_write: + mnt_drop_write(nd.path.mnt); +out_dput: + dput(dentry); +out_unlock: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); path_put(&nd.path); -out: putname(tmp); return error; } -asmlinkage long sys_mknod(const char __user *filename, int mode, unsigned dev) +SYSCALL_DEFINE3(mknod, const char __user *, filename, int, mode, unsigned, dev) { return sys_mknodat(AT_FDCWD, filename, mode, dev); } int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) { - int error = may_create(dir, dentry, NULL); + int error = may_create(dir, dentry); if (error) return error; - if (!dir->i_op || !dir->i_op->mkdir) + if (!dir->i_op->mkdir) return -EPERM; mode &= (S_IRWXUGO|S_ISVTX); @@ -2061,21 +2044,17 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) return error; } -asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode) +SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, int, mode) { int error = 0; char * tmp; struct dentry *dentry; struct nameidata nd; - tmp = getname(pathname); - error = PTR_ERR(tmp); - if (IS_ERR(tmp)) + error = user_path_parent(dfd, pathname, &nd, &tmp); + if (error) goto out_err; - error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd); - if (error) - goto out; dentry = lookup_create(&nd, 1); error = PTR_ERR(dentry); if (IS_ERR(dentry)) @@ -2083,18 +2062,26 @@ asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode) if (!IS_POSIXACL(nd.path.dentry->d_inode)) mode &= ~current->fs->umask; + error = mnt_want_write(nd.path.mnt); + if (error) + goto out_dput; + error = security_path_mkdir(&nd.path, dentry, mode); + if (error) + goto out_drop_write; error = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode); +out_drop_write: + mnt_drop_write(nd.path.mnt); +out_dput: dput(dentry); out_unlock: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); path_put(&nd.path); -out: putname(tmp); out_err: return error; } -asmlinkage long sys_mkdir(const char __user *pathname, int mode) +SYSCALL_DEFINE2(mkdir, const char __user *, pathname, int, mode) { return sys_mkdirat(AT_FDCWD, pathname, mode); } @@ -2133,7 +2120,7 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry) if (error) return error; - if (!dir->i_op || !dir->i_op->rmdir) + if (!dir->i_op->rmdir) return -EPERM; DQUOT_INIT(dir); @@ -2166,25 +2153,24 @@ static long do_rmdir(int dfd, const char __user *pathname) struct dentry *dentry; struct nameidata nd; - name = getname(pathname); - if(IS_ERR(name)) - return PTR_ERR(name); - - error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd); + error = user_path_parent(dfd, pathname, &nd, &name); if (error) - goto exit; + return error; switch(nd.last_type) { - case LAST_DOTDOT: - error = -ENOTEMPTY; - goto exit1; - case LAST_DOT: - error = -EINVAL; - goto exit1; - case LAST_ROOT: - error = -EBUSY; - goto exit1; + case LAST_DOTDOT: + error = -ENOTEMPTY; + goto exit1; + case LAST_DOT: + error = -EINVAL; + goto exit1; + case LAST_ROOT: + error = -EBUSY; + goto exit1; } + + nd.flags &= ~LOOKUP_PARENT; + mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); dentry = lookup_hash(&nd); error = PTR_ERR(dentry); @@ -2193,7 +2179,11 @@ static long do_rmdir(int dfd, const char __user *pathname) error = mnt_want_write(nd.path.mnt); if (error) goto exit3; + error = security_path_rmdir(&nd.path, dentry); + if (error) + goto exit4; error = vfs_rmdir(nd.path.dentry->d_inode, dentry); +exit4: mnt_drop_write(nd.path.mnt); exit3: dput(dentry); @@ -2201,12 +2191,11 @@ exit2: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); exit1: path_put(&nd.path); -exit: putname(name); return error; } -asmlinkage long sys_rmdir(const char __user *pathname) +SYSCALL_DEFINE1(rmdir, const char __user *, pathname) { return do_rmdir(AT_FDCWD, pathname); } @@ -2218,7 +2207,7 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry) if (error) return error; - if (!dir->i_op || !dir->i_op->unlink) + if (!dir->i_op->unlink) return -EPERM; DQUOT_INIT(dir); @@ -2250,22 +2239,22 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry) */ static long do_unlinkat(int dfd, const char __user *pathname) { - int error = 0; - char * name; + int error; + char *name; struct dentry *dentry; struct nameidata nd; struct inode *inode = NULL; - name = getname(pathname); - if(IS_ERR(name)) - return PTR_ERR(name); - - error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd); + error = user_path_parent(dfd, pathname, &nd, &name); if (error) - goto exit; + return error; + error = -EISDIR; if (nd.last_type != LAST_NORM) goto exit1; + + nd.flags &= ~LOOKUP_PARENT; + mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); dentry = lookup_hash(&nd); error = PTR_ERR(dentry); @@ -2279,7 +2268,11 @@ static long do_unlinkat(int dfd, const char __user *pathname) error = mnt_want_write(nd.path.mnt); if (error) goto exit2; + error = security_path_unlink(&nd.path, dentry); + if (error) + goto exit3; error = vfs_unlink(nd.path.dentry->d_inode, dentry); +exit3: mnt_drop_write(nd.path.mnt); exit2: dput(dentry); @@ -2289,7 +2282,6 @@ static long do_unlinkat(int dfd, const char __user *pathname) iput(inode); /* truncate the inode here */ exit1: path_put(&nd.path); -exit: putname(name); return error; @@ -2299,7 +2291,7 @@ slashes: goto exit2; } -asmlinkage long sys_unlinkat(int dfd, const char __user *pathname, int flag) +SYSCALL_DEFINE3(unlinkat, int, dfd, const char __user *, pathname, int, flag) { if ((flag & ~AT_REMOVEDIR) != 0) return -EINVAL; @@ -2310,19 +2302,19 @@ asmlinkage long sys_unlinkat(int dfd, const char __user *pathname, int flag) return do_unlinkat(dfd, pathname); } -asmlinkage long sys_unlink(const char __user *pathname) +SYSCALL_DEFINE1(unlink, const char __user *, pathname) { return do_unlinkat(AT_FDCWD, pathname); } -int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname, int mode) +int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) { - int error = may_create(dir, dentry, NULL); + int error = may_create(dir, dentry); if (error) return error; - if (!dir->i_op || !dir->i_op->symlink) + if (!dir->i_op->symlink) return -EPERM; error = security_inode_symlink(dir, dentry, oldname); @@ -2336,44 +2328,49 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname, i return error; } -asmlinkage long sys_symlinkat(const char __user *oldname, - int newdfd, const char __user *newname) +SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, + int, newdfd, const char __user *, newname) { - int error = 0; - char * from; - char * to; + int error; + char *from; + char *to; struct dentry *dentry; struct nameidata nd; from = getname(oldname); - if(IS_ERR(from)) + if (IS_ERR(from)) return PTR_ERR(from); - to = getname(newname); - error = PTR_ERR(to); - if (IS_ERR(to)) - goto out_putname; - error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd); + error = user_path_parent(newdfd, newname, &nd, &to); if (error) - goto out; + goto out_putname; + dentry = lookup_create(&nd, 0); error = PTR_ERR(dentry); if (IS_ERR(dentry)) goto out_unlock; - error = vfs_symlink(nd.path.dentry->d_inode, dentry, from, S_IALLUGO); + error = mnt_want_write(nd.path.mnt); + if (error) + goto out_dput; + error = security_path_symlink(&nd.path, dentry, from); + if (error) + goto out_drop_write; + error = vfs_symlink(nd.path.dentry->d_inode, dentry, from); +out_drop_write: + mnt_drop_write(nd.path.mnt); +out_dput: dput(dentry); out_unlock: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); path_put(&nd.path); -out: putname(to); out_putname: putname(from); return error; } -asmlinkage long sys_symlink(const char __user *oldname, const char __user *newname) +SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newname) { return sys_symlinkat(oldname, AT_FDCWD, newname); } @@ -2386,7 +2383,7 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de if (!inode) return -ENOENT; - error = may_create(dir, new_dentry, NULL); + error = may_create(dir, new_dentry); if (error) return error; @@ -2398,21 +2395,21 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de */ if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) return -EPERM; - if (!dir->i_op || !dir->i_op->link) + if (!dir->i_op->link) return -EPERM; - if (S_ISDIR(old_dentry->d_inode->i_mode)) + if (S_ISDIR(inode->i_mode)) return -EPERM; error = security_inode_link(old_dentry, dir, new_dentry); if (error) return error; - mutex_lock(&old_dentry->d_inode->i_mutex); + mutex_lock(&inode->i_mutex); DQUOT_INIT(dir); error = dir->i_op->link(old_dentry, dir, new_dentry); - mutex_unlock(&old_dentry->d_inode->i_mutex); + mutex_unlock(&inode->i_mutex); if (!error) - fsnotify_link(dir, old_dentry->d_inode, new_dentry); + fsnotify_link(dir, inode, new_dentry); return error; } @@ -2425,52 +2422,57 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de * with linux 2.0, and to avoid hard-linking to directories * and other special files. --ADM */ -asmlinkage long sys_linkat(int olddfd, const char __user *oldname, - int newdfd, const char __user *newname, - int flags) +SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, + int, newdfd, const char __user *, newname, int, flags) { struct dentry *new_dentry; - struct nameidata nd, old_nd; + struct nameidata nd; + struct path old_path; int error; - char * to; + char *to; if ((flags & ~AT_SYMLINK_FOLLOW) != 0) return -EINVAL; - to = getname(newname); - if (IS_ERR(to)) - return PTR_ERR(to); - - error = __user_walk_fd(olddfd, oldname, - flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0, - &old_nd); + error = user_path_at(olddfd, oldname, + flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0, + &old_path); if (error) - goto exit; - error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd); + return error; + + error = user_path_parent(newdfd, newname, &nd, &to); if (error) goto out; error = -EXDEV; - if (old_nd.path.mnt != nd.path.mnt) + if (old_path.mnt != nd.path.mnt) goto out_release; new_dentry = lookup_create(&nd, 0); error = PTR_ERR(new_dentry); if (IS_ERR(new_dentry)) goto out_unlock; - error = vfs_link(old_nd.path.dentry, nd.path.dentry->d_inode, new_dentry); + error = mnt_want_write(nd.path.mnt); + if (error) + goto out_dput; + error = security_path_link(old_path.dentry, &nd.path, new_dentry); + if (error) + goto out_drop_write; + error = vfs_link(old_path.dentry, nd.path.dentry->d_inode, new_dentry); +out_drop_write: + mnt_drop_write(nd.path.mnt); +out_dput: dput(new_dentry); out_unlock: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); out_release: path_put(&nd.path); -out: - path_put(&old_nd.path); -exit: putname(to); +out: + path_put(&old_path); return error; } -asmlinkage long sys_link(const char __user *oldname, const char __user *newname) +SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname) { return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } @@ -2518,7 +2520,7 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, * we'll need to flip '..'. */ if (new_dir != old_dir) { - error = permission(old_dentry->d_inode, MAY_WRITE, NULL); + error = inode_permission(old_dentry->d_inode, MAY_WRITE); if (error) return error; } @@ -2593,13 +2595,13 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, return error; if (!new_dentry->d_inode) - error = may_create(new_dir, new_dentry, NULL); + error = may_create(new_dir, new_dentry); else error = may_delete(new_dir, new_dentry, is_dir); if (error) return error; - if (!old_dir->i_op || !old_dir->i_op->rename) + if (!old_dir->i_op->rename) return -EPERM; DQUOT_INIT(old_dir); @@ -2621,20 +2623,22 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, return error; } -static int do_rename(int olddfd, const char *oldname, - int newdfd, const char *newname) +SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, + int, newdfd, const char __user *, newname) { - int error = 0; - struct dentry * old_dir, * new_dir; - struct dentry * old_dentry, *new_dentry; - struct dentry * trap; + struct dentry *old_dir, *new_dir; + struct dentry *old_dentry, *new_dentry; + struct dentry *trap; struct nameidata oldnd, newnd; + char *from; + char *to; + int error; - error = do_path_lookup(olddfd, oldname, LOOKUP_PARENT, &oldnd); + error = user_path_parent(olddfd, oldname, &oldnd, &from); if (error) goto exit; - error = do_path_lookup(newdfd, newname, LOOKUP_PARENT, &newnd); + error = user_path_parent(newdfd, newname, &newnd, &to); if (error) goto exit1; @@ -2651,6 +2655,10 @@ static int do_rename(int olddfd, const char *oldname, if (newnd.last_type != LAST_NORM) goto exit2; + oldnd.flags &= ~LOOKUP_PARENT; + newnd.flags &= ~LOOKUP_PARENT; + newnd.flags |= LOOKUP_RENAME_TARGET; + trap = lock_rename(new_dir, old_dir); old_dentry = lookup_hash(&oldnd); @@ -2682,8 +2690,17 @@ static int do_rename(int olddfd, const char *oldname, if (new_dentry == trap) goto exit5; + error = mnt_want_write(oldnd.path.mnt); + if (error) + goto exit5; + error = security_path_rename(&oldnd.path, old_dentry, + &newnd.path, new_dentry); + if (error) + goto exit6; error = vfs_rename(old_dir->d_inode, old_dentry, new_dir->d_inode, new_dentry); +exit6: + mnt_drop_write(oldnd.path.mnt); exit5: dput(new_dentry); exit4: @@ -2692,33 +2709,15 @@ exit3: unlock_rename(new_dir, old_dir); exit2: path_put(&newnd.path); + putname(to); exit1: path_put(&oldnd.path); -exit: - return error; -} - -asmlinkage long sys_renameat(int olddfd, const char __user *oldname, - int newdfd, const char __user *newname) -{ - int error; - char * from; - char * to; - - from = getname(oldname); - if(IS_ERR(from)) - return PTR_ERR(from); - to = getname(newname); - error = PTR_ERR(to); - if (!IS_ERR(to)) { - error = do_rename(olddfd, from, newdfd, to); - putname(to); - } putname(from); +exit: return error; } -asmlinkage long sys_rename(const char __user *oldname, const char __user *newname) +SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newname) { return sys_renameat(AT_FDCWD, oldname, AT_FDCWD, newname); } @@ -2749,16 +2748,17 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen) { struct nameidata nd; void *cookie; + int res; nd.depth = 0; cookie = dentry->d_inode->i_op->follow_link(dentry, &nd); - if (!IS_ERR(cookie)) { - int res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd)); - if (dentry->d_inode->i_op->put_link) - dentry->d_inode->i_op->put_link(dentry, &nd, cookie); - cookie = ERR_PTR(res); - } - return PTR_ERR(cookie); + if (IS_ERR(cookie)) + return PTR_ERR(cookie); + + res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd)); + if (dentry->d_inode->i_op->put_link) + dentry->d_inode->i_op->put_link(dentry, &nd, cookie); + return res; } int vfs_follow_link(struct nameidata *nd, const char *link) @@ -2769,13 +2769,16 @@ int vfs_follow_link(struct nameidata *nd, const char *link) /* get the link contents into pagecache */ static char *page_getlink(struct dentry * dentry, struct page **ppage) { - struct page * page; + char *kaddr; + struct page *page; struct address_space *mapping = dentry->d_inode->i_mapping; page = read_mapping_page(mapping, 0, NULL); if (IS_ERR(page)) return (char*)page; *ppage = page; - return kmap(page); + kaddr = kmap(page); + nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1); + return kaddr; } int page_readlink(struct dentry *dentry, char __user *buffer, int buflen) @@ -2807,18 +2810,23 @@ void page_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) } } -int __page_symlink(struct inode *inode, const char *symname, int len, - gfp_t gfp_mask) +/* + * The nofs argument instructs pagecache_write_begin to pass AOP_FLAG_NOFS + */ +int __page_symlink(struct inode *inode, const char *symname, int len, int nofs) { struct address_space *mapping = inode->i_mapping; struct page *page; void *fsdata; int err; char *kaddr; + unsigned int flags = AOP_FLAG_UNINTERRUPTIBLE; + if (nofs) + flags |= AOP_FLAG_NOFS; retry: err = pagecache_write_begin(NULL, mapping, 0, len-1, - AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata); + flags, &page, &fsdata); if (err) goto fail; @@ -2842,7 +2850,7 @@ fail: int page_symlink(struct inode *inode, const char *symname, int len) { return __page_symlink(inode, symname, len, - mapping_gfp_mask(inode->i_mapping)); + !(mapping_gfp_mask(inode->i_mapping) & __GFP_FS)); } const struct inode_operations page_symlink_inode_operations = { @@ -2851,8 +2859,7 @@ const struct inode_operations page_symlink_inode_operations = { .put_link = page_put_link, }; -EXPORT_SYMBOL(__user_walk); -EXPORT_SYMBOL(__user_walk_fd); +EXPORT_SYMBOL(user_path_at); EXPORT_SYMBOL(follow_down); EXPORT_SYMBOL(follow_up); EXPORT_SYMBOL(get_write_access); /* binfmt_aout */ @@ -2866,9 +2873,9 @@ EXPORT_SYMBOL(__page_symlink); EXPORT_SYMBOL(page_symlink); EXPORT_SYMBOL(page_symlink_inode_operations); EXPORT_SYMBOL(path_lookup); +EXPORT_SYMBOL(kern_path); EXPORT_SYMBOL(vfs_path_lookup); -EXPORT_SYMBOL(permission); -EXPORT_SYMBOL(vfs_permission); +EXPORT_SYMBOL(inode_permission); EXPORT_SYMBOL(file_permission); EXPORT_SYMBOL(unlock_rename); EXPORT_SYMBOL(vfs_create); @@ -2884,3 +2891,10 @@ EXPORT_SYMBOL(vfs_symlink); EXPORT_SYMBOL(vfs_unlink); EXPORT_SYMBOL(dentry_unhash); EXPORT_SYMBOL(generic_readlink); + +/* to be mentioned only in INIT_TASK */ +struct fs_struct init_fs = { + .count = ATOMIC_INIT(1), + .lock = __RW_LOCK_UNLOCKED(init_fs.lock), + .umask = 0022, +};