diff options
author | Daniel Rosenberg <drosen@google.com> | 2016-10-26 16:27:45 -0700 |
---|---|---|
committer | Daniel Rosenberg <drosen@google.com> | 2017-01-26 15:53:30 -0800 |
commit | 21fc44e40ae3c574c288159846ab5a4762bd0e3f (patch) | |
tree | 82eadbaabbb1e9d3c01d80dc18b0304ce64ee0df /fs/namei.c | |
parent | 0ad2dd493c2fb614cb0b7f2355990ce035224590 (diff) |
ANDROID: vfs: Add permission2 for filesystems with per mount permissions
This allows filesystems to use their mount private data to
influence the permssions they return in permission2. It has
been separated into a new call to avoid disrupting current
permission users.
Change-Id: I9d416e3b8b6eca84ef3e336bd2af89ddd51df6ca
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Diffstat (limited to 'fs/namei.c')
-rw-r--r-- | fs/namei.c | 175 |
1 files changed, 125 insertions, 50 deletions
diff --git a/fs/namei.c b/fs/namei.c index 0c3974cd3ecd..82c7ec6532d5 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -373,9 +373,11 @@ EXPORT_SYMBOL(generic_permission); * flag in inode->i_opflags, that says "this has not special * permission function, use the fast case". */ -static inline int do_inode_permission(struct inode *inode, int mask) +static inline int do_inode_permission(struct vfsmount *mnt, struct inode *inode, int mask) { if (unlikely(!(inode->i_opflags & IOP_FASTPERM))) { + if (likely(mnt && inode->i_op->permission2)) + return inode->i_op->permission2(mnt, inode, mask); if (likely(inode->i_op->permission)) return inode->i_op->permission(inode, mask); @@ -399,7 +401,7 @@ static inline int do_inode_permission(struct inode *inode, int mask) * This does not check for a read-only file system. You probably want * inode_permission(). */ -int __inode_permission(struct inode *inode, int mask) +int __inode_permission2(struct vfsmount *mnt, struct inode *inode, int mask) { int retval; @@ -411,7 +413,7 @@ int __inode_permission(struct inode *inode, int mask) return -EACCES; } - retval = do_inode_permission(inode, mask); + retval = do_inode_permission(mnt, inode, mask); if (retval) return retval; @@ -419,7 +421,14 @@ int __inode_permission(struct inode *inode, int mask) if (retval) return retval; - return security_inode_permission(inode, mask); + retval = security_inode_permission(inode, mask); + return retval; +} +EXPORT_SYMBOL(__inode_permission2); + +int __inode_permission(struct inode *inode, int mask) +{ + return __inode_permission2(NULL, inode, mask); } EXPORT_SYMBOL(__inode_permission); @@ -455,14 +464,20 @@ static int sb_permission(struct super_block *sb, struct inode *inode, int mask) * * When checking for MAY_APPEND, MAY_WRITE must also be set in @mask. */ -int inode_permission(struct inode *inode, int mask) +int inode_permission2(struct vfsmount *mnt, struct inode *inode, int mask) { int retval; retval = sb_permission(inode->i_sb, inode, mask); if (retval) return retval; - return __inode_permission(inode, mask); + return __inode_permission2(mnt, inode, mask); +} +EXPORT_SYMBOL(inode_permission2); + +int inode_permission(struct inode *inode, int mask) +{ + return inode_permission2(NULL, inode, mask); } EXPORT_SYMBOL(inode_permission); @@ -1643,13 +1658,13 @@ static int lookup_slow(struct nameidata *nd, struct path *path) static inline int may_lookup(struct nameidata *nd) { if (nd->flags & LOOKUP_RCU) { - int err = inode_permission(nd->inode, MAY_EXEC|MAY_NOT_BLOCK); + int err = inode_permission2(nd->path.mnt, nd->inode, MAY_EXEC|MAY_NOT_BLOCK); if (err != -ECHILD) return err; if (unlazy_walk(nd, NULL, 0)) return -ECHILD; } - return inode_permission(nd->inode, MAY_EXEC); + return inode_permission2(nd->path.mnt, nd->inode, MAY_EXEC); } static inline int handle_dots(struct nameidata *nd, int type) @@ -1998,11 +2013,12 @@ static const char *path_init(struct nameidata *nd, unsigned flags) nd->depth = 0; if (flags & LOOKUP_ROOT) { struct dentry *root = nd->root.dentry; + struct vfsmount *mnt = nd->root.mnt; struct inode *inode = root->d_inode; if (*s) { if (!d_can_lookup(root)) return ERR_PTR(-ENOTDIR); - retval = inode_permission(inode, MAY_EXEC); + retval = inode_permission2(mnt, inode, MAY_EXEC); if (retval) return ERR_PTR(retval); } @@ -2273,13 +2289,14 @@ EXPORT_SYMBOL(vfs_path_lookup); /** * lookup_one_len - filesystem helper to lookup single pathname component * @name: pathname component to lookup + * @mnt: mount we are looking up on * @base: base directory to lookup from * @len: maximum length @len should be interpreted to * * Note that this routine is purely a helper for filesystem usage and should * not be called by generic code. */ -struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) +struct dentry *lookup_one_len2(const char *name, struct vfsmount *mnt, struct dentry *base, int len) { struct qstr this; unsigned int c; @@ -2313,12 +2330,18 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) return ERR_PTR(err); } - err = inode_permission(base->d_inode, MAY_EXEC); + err = inode_permission2(mnt, base->d_inode, MAY_EXEC); if (err) return ERR_PTR(err); return __lookup_hash(&this, base, 0); } +EXPORT_SYMBOL(lookup_one_len2); + +struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) +{ + return lookup_one_len2(name, NULL, base, len); +} EXPORT_SYMBOL(lookup_one_len); int user_path_at_empty(int dfd, const char __user *name, unsigned flags, @@ -2545,7 +2568,7 @@ EXPORT_SYMBOL(__check_sticky); * 10. We don't allow removal of NFS sillyrenamed files; it's handled by * nfs_async_unlink(). */ -static int may_delete(struct inode *dir, struct dentry *victim, bool isdir) +static int may_delete(struct vfsmount *mnt, struct inode *dir, struct dentry *victim, bool isdir) { struct inode *inode = d_backing_inode(victim); int error; @@ -2557,7 +2580,7 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir) BUG_ON(victim->d_parent->d_inode != dir); audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE); - error = inode_permission(dir, MAY_WRITE | MAY_EXEC); + error = inode_permission2(mnt, dir, MAY_WRITE | MAY_EXEC); if (error) return error; if (IS_APPEND(dir)) @@ -2588,14 +2611,14 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool 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) +static inline int may_create(struct vfsmount *mnt, struct inode *dir, struct dentry *child) { audit_inode_child(dir, child, AUDIT_TYPE_CHILD_CREATE); if (child->d_inode) return -EEXIST; if (IS_DEADDIR(dir)) return -ENOENT; - return inode_permission(dir, MAY_WRITE | MAY_EXEC); + return inode_permission2(mnt, dir, MAY_WRITE | MAY_EXEC); } /* @@ -2642,10 +2665,10 @@ void unlock_rename(struct dentry *p1, struct dentry *p2) } EXPORT_SYMBOL(unlock_rename); -int vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, - bool want_excl) +int vfs_create2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry, + umode_t mode, bool want_excl) { - int error = may_create(dir, dentry); + int error = may_create(mnt, dir, dentry); if (error) return error; @@ -2661,11 +2684,19 @@ int vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, fsnotify_create(dir, dentry); return error; } +EXPORT_SYMBOL(vfs_create2); + +int vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, + bool want_excl) +{ + return vfs_create2(NULL, dir, dentry, mode, want_excl); +} EXPORT_SYMBOL(vfs_create); static int may_open(struct path *path, int acc_mode, int flag) { struct dentry *dentry = path->dentry; + struct vfsmount *mnt = path->mnt; struct inode *inode = dentry->d_inode; int error; @@ -2694,7 +2725,7 @@ static int may_open(struct path *path, int acc_mode, int flag) break; } - error = inode_permission(inode, acc_mode); + error = inode_permission2(mnt, inode, acc_mode); if (error) return error; @@ -2750,7 +2781,7 @@ static int may_o_create(struct path *dir, struct dentry *dentry, umode_t mode) if (error) return error; - error = inode_permission(dir->dentry->d_inode, MAY_WRITE | MAY_EXEC); + error = inode_permission2(dir->mnt, dir->dentry->d_inode, MAY_WRITE | MAY_EXEC); if (error) return error; @@ -2948,6 +2979,7 @@ static int lookup_open(struct nameidata *nd, struct path *path, bool got_write, int *opened) { struct dentry *dir = nd->path.dentry; + struct vfsmount *mnt = nd->path.mnt; struct inode *dir_inode = dir->d_inode; struct dentry *dentry; int error; @@ -2995,7 +3027,7 @@ static int lookup_open(struct nameidata *nd, struct path *path, error = security_path_mknod(&nd->path, dentry, mode, 0); if (error) goto out_dput; - error = vfs_create(dir->d_inode, dentry, mode, + error = vfs_create2(mnt, dir->d_inode, dentry, mode, nd->flags & LOOKUP_EXCL); if (error) goto out_dput; @@ -3254,7 +3286,7 @@ static int do_tmpfile(struct nameidata *nd, unsigned flags, goto out; dir = path.dentry->d_inode; /* we want directory to be writable */ - error = inode_permission(dir, MAY_WRITE | MAY_EXEC); + error = inode_permission2(path.mnt, dir, MAY_WRITE | MAY_EXEC); if (error) goto out2; if (!dir->i_op->tmpfile) { @@ -3488,9 +3520,9 @@ inline struct dentry *user_path_create(int dfd, const char __user *pathname, } EXPORT_SYMBOL(user_path_create); -int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) +int vfs_mknod2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) { - int error = may_create(dir, dentry); + int error = may_create(mnt, dir, dentry); if (error) return error; @@ -3514,6 +3546,12 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) fsnotify_create(dir, dentry); return error; } +EXPORT_SYMBOL(vfs_mknod2); + +int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) +{ + return vfs_mknod2(NULL, dir, dentry, mode, dev); +} EXPORT_SYMBOL(vfs_mknod); static int may_mknod(umode_t mode) @@ -3556,10 +3594,10 @@ retry: goto out; switch (mode & S_IFMT) { case 0: case S_IFREG: - error = vfs_create(path.dentry->d_inode,dentry,mode,true); + error = vfs_create2(path.mnt, path.dentry->d_inode,dentry,mode,true); break; case S_IFCHR: case S_IFBLK: - error = vfs_mknod(path.dentry->d_inode,dentry,mode, + error = vfs_mknod2(path.mnt, path.dentry->d_inode,dentry,mode, new_decode_dev(dev)); break; case S_IFIFO: case S_IFSOCK: @@ -3580,9 +3618,9 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, umode_t, mode, unsigned, d return sys_mknodat(AT_FDCWD, filename, mode, dev); } -int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) +int vfs_mkdir2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry, umode_t mode) { - int error = may_create(dir, dentry); + int error = may_create(mnt, dir, dentry); unsigned max_links = dir->i_sb->s_max_links; if (error) @@ -3604,6 +3642,12 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) fsnotify_mkdir(dir, dentry); return error; } +EXPORT_SYMBOL(vfs_mkdir2); + +int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + return vfs_mkdir2(NULL, dir, dentry, mode); +} EXPORT_SYMBOL(vfs_mkdir); SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode) @@ -3622,7 +3666,7 @@ retry: mode &= ~current_umask(); error = security_path_mkdir(&path, dentry, mode); if (!error) - error = vfs_mkdir(path.dentry->d_inode, dentry, mode); + error = vfs_mkdir2(path.mnt, path.dentry->d_inode, dentry, mode); done_path_create(&path, dentry); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; @@ -3661,9 +3705,9 @@ void dentry_unhash(struct dentry *dentry) } EXPORT_SYMBOL(dentry_unhash); -int vfs_rmdir(struct inode *dir, struct dentry *dentry) +int vfs_rmdir2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry) { - int error = may_delete(dir, dentry, 1); + int error = may_delete(mnt, dir, dentry, 1); if (error) return error; @@ -3698,6 +3742,10 @@ out: d_delete(dentry); return error; } +int vfs_rmdir(struct inode *dir, struct dentry *dentry) +{ + return vfs_rmdir2(NULL, dir, dentry); +} EXPORT_SYMBOL(vfs_rmdir); static long do_rmdir(int dfd, const char __user *pathname) @@ -3743,7 +3791,7 @@ retry: error = security_path_rmdir(&path, dentry); if (error) goto exit3; - error = vfs_rmdir(path.dentry->d_inode, dentry); + error = vfs_rmdir2(path.mnt, path.dentry->d_inode, dentry); exit3: dput(dentry); exit2: @@ -3782,10 +3830,10 @@ SYSCALL_DEFINE1(rmdir, const char __user *, pathname) * be appropriate for callers that expect the underlying filesystem not * to be NFS exported. */ -int vfs_unlink(struct inode *dir, struct dentry *dentry, struct inode **delegated_inode) +int vfs_unlink2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry, struct inode **delegated_inode) { struct inode *target = dentry->d_inode; - int error = may_delete(dir, dentry, 0); + int error = may_delete(mnt, dir, dentry, 0); if (error) return error; @@ -3820,6 +3868,12 @@ out: return error; } +EXPORT_SYMBOL(vfs_unlink2); + +int vfs_unlink(struct inode *dir, struct dentry *dentry, struct inode **delegated_inode) +{ + return vfs_unlink2(NULL, dir, dentry, delegated_inode); +} EXPORT_SYMBOL(vfs_unlink); /* @@ -3867,7 +3921,7 @@ retry_deleg: error = security_path_unlink(&path, dentry); if (error) goto exit2; - error = vfs_unlink(path.dentry->d_inode, dentry, &delegated_inode); + error = vfs_unlink2(path.mnt, path.dentry->d_inode, dentry, &delegated_inode); exit2: dput(dentry); } @@ -3917,9 +3971,9 @@ 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 vfs_symlink2(struct vfsmount *mnt, struct inode *dir, struct dentry *dentry, const char *oldname) { - int error = may_create(dir, dentry); + int error = may_create(mnt, dir, dentry); if (error) return error; @@ -3936,6 +3990,12 @@ int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) fsnotify_create(dir, dentry); return error; } +EXPORT_SYMBOL(vfs_symlink2); + +int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) +{ + return vfs_symlink2(NULL, dir, dentry, oldname); +} EXPORT_SYMBOL(vfs_symlink); SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, @@ -3958,7 +4018,7 @@ retry: error = security_path_symlink(&path, dentry, from->name); if (!error) - error = vfs_symlink(path.dentry->d_inode, dentry, from->name); + error = vfs_symlink2(path.mnt, path.dentry->d_inode, dentry, from->name); done_path_create(&path, dentry); if (retry_estale(error, lookup_flags)) { lookup_flags |= LOOKUP_REVAL; @@ -3993,7 +4053,7 @@ SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newn * be appropriate for callers that expect the underlying filesystem not * to be NFS exported. */ -int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry, struct inode **delegated_inode) +int vfs_link2(struct vfsmount *mnt, struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry, struct inode **delegated_inode) { struct inode *inode = old_dentry->d_inode; unsigned max_links = dir->i_sb->s_max_links; @@ -4002,7 +4062,7 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de if (!inode) return -ENOENT; - error = may_create(dir, new_dentry); + error = may_create(mnt, dir, new_dentry); if (error) return error; @@ -4045,6 +4105,12 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de fsnotify_link(dir, inode, new_dentry); return error; } +EXPORT_SYMBOL(vfs_link2); + +int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry, struct inode **delegated_inode) +{ + return vfs_link2(NULL, old_dentry, dir, new_dentry, delegated_inode); +} EXPORT_SYMBOL(vfs_link); /* @@ -4100,7 +4166,7 @@ retry: error = security_path_link(old_path.dentry, &new_path, new_dentry); if (error) goto out_dput; - error = vfs_link(old_path.dentry, new_path.dentry->d_inode, new_dentry, &delegated_inode); + error = vfs_link2(old_path.mnt, old_path.dentry, new_path.dentry->d_inode, new_dentry, &delegated_inode); out_dput: done_path_create(&new_path, new_dentry); if (delegated_inode) { @@ -4175,7 +4241,8 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname * ->i_mutex on parents, which works but leads to some truly excessive * locking]. */ -int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, +int vfs_rename2(struct vfsmount *mnt, + struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, struct inode **delegated_inode, unsigned int flags) { @@ -4190,19 +4257,19 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, if (source == target) return 0; - error = may_delete(old_dir, old_dentry, is_dir); + error = may_delete(mnt, old_dir, old_dentry, is_dir); if (error) return error; if (!target) { - error = may_create(new_dir, new_dentry); + error = may_create(mnt, new_dir, new_dentry); } else { new_is_dir = d_is_dir(new_dentry); if (!(flags & RENAME_EXCHANGE)) - error = may_delete(new_dir, new_dentry, is_dir); + error = may_delete(mnt, new_dir, new_dentry, is_dir); else - error = may_delete(new_dir, new_dentry, new_is_dir); + error = may_delete(mnt, new_dir, new_dentry, new_is_dir); } if (error) return error; @@ -4219,12 +4286,12 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, */ if (new_dir != old_dir) { if (is_dir) { - error = inode_permission(source, MAY_WRITE); + error = inode_permission2(mnt, source, MAY_WRITE); if (error) return error; } if ((flags & RENAME_EXCHANGE) && new_is_dir) { - error = inode_permission(target, MAY_WRITE); + error = inode_permission2(mnt, target, MAY_WRITE); if (error) return error; } @@ -4307,6 +4374,14 @@ out: return error; } +EXPORT_SYMBOL(vfs_rename2); + +int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + struct inode **delegated_inode, unsigned int flags) +{ + return vfs_rename2(NULL, old_dir, old_dentry, new_dir, new_dentry, delegated_inode, flags); +} EXPORT_SYMBOL(vfs_rename); SYSCALL_DEFINE5(renameat2, int, olddfd, const char __user *, oldname, @@ -4420,7 +4495,7 @@ retry_deleg: &new_path, new_dentry, flags); if (error) goto exit5; - error = vfs_rename(old_path.dentry->d_inode, old_dentry, + error = vfs_rename2(old_path.mnt, old_path.dentry->d_inode, old_dentry, new_path.dentry->d_inode, new_dentry, &delegated_inode, flags); exit5: @@ -4465,7 +4540,7 @@ SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newna int vfs_whiteout(struct inode *dir, struct dentry *dentry) { - int error = may_create(dir, dentry); + int error = may_create(NULL, dir, dentry); if (error) return error; |