ANDROID: Included sdcardfs source code for kernel 3.0
Only included the source code as is for kernel 3.0. Following patches
take care of porting this file system to version 3.10.
Change-Id: I09e76db77cd98a059053ba5b6fd88572a4b75b5b
Signed-off-by: Daniel Campello <campello@google.com>
diff --git a/fs/sdcardfs/inode.c b/fs/sdcardfs/inode.c
new file mode 100644
index 0000000..e8ed042
--- /dev/null
+++ b/fs/sdcardfs/inode.c
@@ -0,0 +1,886 @@
+/*
+ * fs/sdcardfs/inode.c
+ *
+ * Copyright (c) 2013 Samsung Electronics Co. Ltd
+ * Authors: Daeho Jeong, Woojoong Lee, Seunghwan Hyun,
+ * Sunghwan Yun, Sungjong Seo
+ *
+ * This program has been developed as a stackable file system based on
+ * the WrapFS which written by
+ *
+ * Copyright (c) 1998-2011 Erez Zadok
+ * Copyright (c) 2009 Shrikar Archak
+ * Copyright (c) 2003-2011 Stony Brook University
+ * Copyright (c) 2003-2011 The Research Foundation of SUNY
+ *
+ * This file is dual licensed. It may be redistributed and/or modified
+ * under the terms of the Apache 2.0 License OR version 2 of the GNU
+ * General Public License.
+ */
+
+#include "sdcardfs.h"
+
+/* Do not directly use this function. Use OVERRIDE_CRED() instead. */
+const struct cred * override_fsids(struct sdcardfs_sb_info* sbi)
+{
+ struct cred * cred;
+ const struct cred * old_cred;
+
+ cred = prepare_creds();
+ if (!cred)
+ return NULL;
+
+ cred->fsuid = sbi->options.fs_low_uid;
+ cred->fsgid = sbi->options.fs_low_gid;
+
+ old_cred = override_creds(cred);
+
+ return old_cred;
+}
+
+/* Do not directly use this function, use REVERT_CRED() instead. */
+void revert_fsids(const struct cred * old_cred)
+{
+ const struct cred * cur_cred;
+
+ cur_cred = current->cred;
+ revert_creds(old_cred);
+ put_cred(cur_cred);
+}
+
+static int sdcardfs_create(struct inode *dir, struct dentry *dentry,
+ int mode, struct nameidata *nd)
+{
+ int err = 0;
+ struct dentry *lower_dentry;
+ struct dentry *lower_parent_dentry = NULL;
+ struct path lower_path, saved_path;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ const struct cred *saved_cred = NULL;
+
+ int has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
+ if(!check_caller_access_to_name(dir, dentry->d_name.name, sbi->options.derive, 1, has_rw)) {
+ printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
+ " dentry: %s, task:%s\n",
+ __func__, dentry->d_name.name, current->comm);
+ err = -EACCES;
+ goto out_eacces;
+ }
+
+ /* save current_cred and override it */
+ OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred);
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ lower_parent_dentry = lock_parent(lower_dentry);
+
+ err = mnt_want_write(lower_path.mnt);
+ if (err)
+ goto out_unlock;
+
+ pathcpy(&saved_path, &nd->path);
+ pathcpy(&nd->path, &lower_path);
+
+ /* set last 16bytes of mode field to 0664 */
+ mode = (mode & S_IFMT) | 00664;
+ err = vfs_create(lower_parent_dentry->d_inode, lower_dentry, mode, nd);
+
+ pathcpy(&nd->path, &saved_path);
+ if (err)
+ goto out;
+
+ err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path);
+ if (err)
+ goto out;
+ fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir));
+ fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
+
+out:
+ mnt_drop_write(lower_path.mnt);
+out_unlock:
+ unlock_dir(lower_parent_dentry);
+ sdcardfs_put_lower_path(dentry, &lower_path);
+ REVERT_CRED(saved_cred);
+out_eacces:
+ return err;
+}
+
+#if 0
+static int sdcardfs_link(struct dentry *old_dentry, struct inode *dir,
+ struct dentry *new_dentry)
+{
+ struct dentry *lower_old_dentry;
+ struct dentry *lower_new_dentry;
+ struct dentry *lower_dir_dentry;
+ u64 file_size_save;
+ int err;
+ struct path lower_old_path, lower_new_path;
+
+ OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb));
+
+ file_size_save = i_size_read(old_dentry->d_inode);
+ sdcardfs_get_lower_path(old_dentry, &lower_old_path);
+ sdcardfs_get_lower_path(new_dentry, &lower_new_path);
+ lower_old_dentry = lower_old_path.dentry;
+ lower_new_dentry = lower_new_path.dentry;
+ lower_dir_dentry = lock_parent(lower_new_dentry);
+
+ err = mnt_want_write(lower_new_path.mnt);
+ if (err)
+ goto out_unlock;
+
+ err = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
+ lower_new_dentry);
+ if (err || !lower_new_dentry->d_inode)
+ goto out;
+
+ err = sdcardfs_interpose(new_dentry, dir->i_sb, &lower_new_path);
+ if (err)
+ goto out;
+ fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
+ fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
+ old_dentry->d_inode->i_nlink =
+ sdcardfs_lower_inode(old_dentry->d_inode)->i_nlink;
+ i_size_write(new_dentry->d_inode, file_size_save);
+out:
+ mnt_drop_write(lower_new_path.mnt);
+out_unlock:
+ unlock_dir(lower_dir_dentry);
+ sdcardfs_put_lower_path(old_dentry, &lower_old_path);
+ sdcardfs_put_lower_path(new_dentry, &lower_new_path);
+ REVERT_CRED();
+ return err;
+}
+#endif
+
+static int sdcardfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ int err;
+ struct dentry *lower_dentry;
+ struct inode *lower_dir_inode = sdcardfs_lower_inode(dir);
+ struct dentry *lower_dir_dentry;
+ struct path lower_path;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ const struct cred *saved_cred = NULL;
+
+ int has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
+ if(!check_caller_access_to_name(dir, dentry->d_name.name, sbi->options.derive, 1, has_rw)) {
+ printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
+ " dentry: %s, task:%s\n",
+ __func__, dentry->d_name.name, current->comm);
+ err = -EACCES;
+ goto out_eacces;
+ }
+
+ /* save current_cred and override it */
+ OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred);
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ dget(lower_dentry);
+ lower_dir_dentry = lock_parent(lower_dentry);
+
+ err = mnt_want_write(lower_path.mnt);
+ if (err)
+ goto out_unlock;
+ err = vfs_unlink(lower_dir_inode, lower_dentry);
+
+ /*
+ * Note: unlinking on top of NFS can cause silly-renamed files.
+ * Trying to delete such files results in EBUSY from NFS
+ * below. Silly-renamed files will get deleted by NFS later on, so
+ * we just need to detect them here and treat such EBUSY errors as
+ * if the upper file was successfully deleted.
+ */
+ if (err == -EBUSY && lower_dentry->d_flags & DCACHE_NFSFS_RENAMED)
+ err = 0;
+ if (err)
+ goto out;
+ fsstack_copy_attr_times(dir, lower_dir_inode);
+ fsstack_copy_inode_size(dir, lower_dir_inode);
+ dentry->d_inode->i_nlink =
+ sdcardfs_lower_inode(dentry->d_inode)->i_nlink;
+ dentry->d_inode->i_ctime = dir->i_ctime;
+ d_drop(dentry); /* this is needed, else LTP fails (VFS won't do it) */
+out:
+ mnt_drop_write(lower_path.mnt);
+out_unlock:
+ unlock_dir(lower_dir_dentry);
+ dput(lower_dentry);
+ sdcardfs_put_lower_path(dentry, &lower_path);
+ REVERT_CRED(saved_cred);
+out_eacces:
+ return err;
+}
+
+#if 0
+static int sdcardfs_symlink(struct inode *dir, struct dentry *dentry,
+ const char *symname)
+{
+ int err = 0;
+ struct dentry *lower_dentry;
+ struct dentry *lower_parent_dentry = NULL;
+ struct path lower_path;
+
+ OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb));
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ lower_parent_dentry = lock_parent(lower_dentry);
+
+ err = mnt_want_write(lower_path.mnt);
+ if (err)
+ goto out_unlock;
+ err = vfs_symlink(lower_parent_dentry->d_inode, lower_dentry, symname);
+ if (err)
+ goto out;
+ err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path);
+ if (err)
+ goto out;
+ fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir));
+ fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
+
+out:
+ mnt_drop_write(lower_path.mnt);
+out_unlock:
+ unlock_dir(lower_parent_dentry);
+ sdcardfs_put_lower_path(dentry, &lower_path);
+ REVERT_CRED();
+ return err;
+}
+#endif
+
+static int touch(char *abs_path, mode_t mode) {
+ struct file *filp = filp_open(abs_path, O_RDWR|O_CREAT|O_EXCL|O_NOFOLLOW, mode);
+ if (IS_ERR(filp)) {
+ if (PTR_ERR(filp) == -EEXIST) {
+ return 0;
+ }
+ else {
+ printk(KERN_ERR "sdcardfs: failed to open(%s): %ld\n",
+ abs_path, PTR_ERR(filp));
+ return PTR_ERR(filp);
+ }
+ }
+ filp_close(filp, current->files);
+ return 0;
+}
+
+static int sdcardfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+ int err = 0;
+ int make_nomedia_in_obb = 0;
+ struct dentry *lower_dentry;
+ struct dentry *lower_parent_dentry = NULL;
+ struct path lower_path;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ const struct cred *saved_cred = NULL;
+ struct sdcardfs_inode_info *pi = SDCARDFS_I(dir);
+ char *page_buf;
+ char *nomedia_dir_name;
+ char *nomedia_fullpath;
+ int fullpath_namelen;
+ int touch_err = 0;
+
+ int has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
+ if(!check_caller_access_to_name(dir, dentry->d_name.name, sbi->options.derive, 1, has_rw)) {
+ printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
+ " dentry: %s, task:%s\n",
+ __func__, dentry->d_name.name, current->comm);
+ err = -EACCES;
+ goto out_eacces;
+ }
+
+ /* save current_cred and override it */
+ OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred);
+
+ /* check disk space */
+ if (!check_min_free_space(dentry, 0, 1)) {
+ printk(KERN_INFO "sdcardfs: No minimum free space.\n");
+ err = -ENOSPC;
+ goto out_revert;
+ }
+
+ /* the lower_dentry is negative here */
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ lower_parent_dentry = lock_parent(lower_dentry);
+
+ err = mnt_want_write(lower_path.mnt);
+ if (err)
+ goto out_unlock;
+
+ /* set last 16bytes of mode field to 0775 */
+ mode = (mode & S_IFMT) | 00775;
+ err = vfs_mkdir(lower_parent_dentry->d_inode, lower_dentry, mode);
+
+ if (err)
+ goto out;
+
+ /* if it is a local obb dentry, setup it with the base obbpath */
+ if(need_graft_path(dentry)) {
+
+ err = setup_obb_dentry(dentry, &lower_path);
+ if(err) {
+ /* if the sbi->obbpath is not available, the lower_path won't be
+ * changed by setup_obb_dentry() but the lower path is saved to
+ * its orig_path. this dentry will be revalidated later.
+ * but now, the lower_path should be NULL */
+ sdcardfs_put_reset_lower_path(dentry);
+
+ /* the newly created lower path which saved to its orig_path or
+ * the lower_path is the base obbpath.
+ * therefore, an additional path_get is required */
+ path_get(&lower_path);
+ } else
+ make_nomedia_in_obb = 1;
+ }
+
+ err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path);
+ if (err)
+ goto out;
+
+ fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir));
+ fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
+ /* update number of links on parent directory */
+ dir->i_nlink = sdcardfs_lower_inode(dir)->i_nlink;
+
+ if ((sbi->options.derive == DERIVE_UNIFIED) && (!strcasecmp(dentry->d_name.name, "obb"))
+ && (pi->perm == PERM_ANDROID) && (pi->userid == 0))
+ make_nomedia_in_obb = 1;
+
+ /* When creating /Android/data and /Android/obb, mark them as .nomedia */
+ if (make_nomedia_in_obb ||
+ ((pi->perm == PERM_ANDROID) && (!strcasecmp(dentry->d_name.name, "data")))) {
+
+ page_buf = (char *)__get_free_page(GFP_KERNEL);
+ if (!page_buf) {
+ printk(KERN_ERR "sdcardfs: failed to allocate page buf\n");
+ goto out;
+ }
+
+ nomedia_dir_name = d_absolute_path(&lower_path, page_buf, PAGE_SIZE);
+ if (IS_ERR(nomedia_dir_name)) {
+ free_page((unsigned long)page_buf);
+ printk(KERN_ERR "sdcardfs: failed to get .nomedia dir name\n");
+ goto out;
+ }
+
+ fullpath_namelen = page_buf + PAGE_SIZE - nomedia_dir_name - 1;
+ fullpath_namelen += strlen("/.nomedia");
+ nomedia_fullpath = kzalloc(fullpath_namelen + 1, GFP_KERNEL);
+ if (!nomedia_fullpath) {
+ free_page((unsigned long)page_buf);
+ printk(KERN_ERR "sdcardfs: failed to allocate .nomedia fullpath buf\n");
+ goto out;
+ }
+
+ strcpy(nomedia_fullpath, nomedia_dir_name);
+ free_page((unsigned long)page_buf);
+ strcat(nomedia_fullpath, "/.nomedia");
+ touch_err = touch(nomedia_fullpath, 0664);
+ if (touch_err) {
+ printk(KERN_ERR "sdcardfs: failed to touch(%s): %d\n",
+ nomedia_fullpath, touch_err);
+ kfree(nomedia_fullpath);
+ goto out;
+ }
+ kfree(nomedia_fullpath);
+ }
+out:
+ mnt_drop_write(lower_path.mnt);
+out_unlock:
+ unlock_dir(lower_parent_dentry);
+ sdcardfs_put_lower_path(dentry, &lower_path);
+out_revert:
+ REVERT_CRED(saved_cred);
+out_eacces:
+ return err;
+}
+
+static int sdcardfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct dentry *lower_dentry;
+ struct dentry *lower_dir_dentry;
+ int err;
+ struct path lower_path;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ const struct cred *saved_cred = NULL;
+ //char *path_s = NULL;
+
+ int has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
+ if(!check_caller_access_to_name(dir, dentry->d_name.name, sbi->options.derive, 1, has_rw)) {
+ printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
+ " dentry: %s, task:%s\n",
+ __func__, dentry->d_name.name, current->comm);
+ err = -EACCES;
+ goto out_eacces;
+ }
+
+ /* save current_cred and override it */
+ OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb), saved_cred);
+
+ /* sdcardfs_get_real_lower(): in case of remove an user's obb dentry
+ * the dentry on the original path should be deleted. */
+ sdcardfs_get_real_lower(dentry, &lower_path);
+
+ lower_dentry = lower_path.dentry;
+ lower_dir_dentry = lock_parent(lower_dentry);
+
+ err = mnt_want_write(lower_path.mnt);
+ if (err)
+ goto out_unlock;
+ err = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
+ if (err)
+ goto out;
+
+ d_drop(dentry); /* drop our dentry on success (why not VFS's job?) */
+ if (dentry->d_inode)
+ clear_nlink(dentry->d_inode);
+ fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
+ fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
+ dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
+
+out:
+ mnt_drop_write(lower_path.mnt);
+out_unlock:
+ unlock_dir(lower_dir_dentry);
+ sdcardfs_put_real_lower(dentry, &lower_path);
+ REVERT_CRED(saved_cred);
+out_eacces:
+ return err;
+}
+
+#if 0
+static int sdcardfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+ dev_t dev)
+{
+ int err = 0;
+ struct dentry *lower_dentry;
+ struct dentry *lower_parent_dentry = NULL;
+ struct path lower_path;
+
+ OVERRIDE_CRED(SDCARDFS_SB(dir->i_sb));
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ lower_parent_dentry = lock_parent(lower_dentry);
+
+ err = mnt_want_write(lower_path.mnt);
+ if (err)
+ goto out_unlock;
+ err = vfs_mknod(lower_parent_dentry->d_inode, lower_dentry, mode, dev);
+ if (err)
+ goto out;
+
+ err = sdcardfs_interpose(dentry, dir->i_sb, &lower_path);
+ if (err)
+ goto out;
+ fsstack_copy_attr_times(dir, sdcardfs_lower_inode(dir));
+ fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode);
+
+out:
+ mnt_drop_write(lower_path.mnt);
+out_unlock:
+ unlock_dir(lower_parent_dentry);
+ sdcardfs_put_lower_path(dentry, &lower_path);
+ REVERT_CRED();
+ return err;
+}
+#endif
+
+/*
+ * The locking rules in sdcardfs_rename are complex. We could use a simpler
+ * superblock-level name-space lock for renames and copy-ups.
+ */
+static int sdcardfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ int err = 0;
+ struct dentry *lower_old_dentry = NULL;
+ struct dentry *lower_new_dentry = NULL;
+ struct dentry *lower_old_dir_dentry = NULL;
+ struct dentry *lower_new_dir_dentry = NULL;
+ struct dentry *trap = NULL;
+ struct dentry *new_parent = NULL;
+ struct path lower_old_path, lower_new_path;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(old_dentry->d_sb);
+ const struct cred *saved_cred = NULL;
+
+ int has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
+ if(!check_caller_access_to_name(old_dir, old_dentry->d_name.name,
+ sbi->options.derive, 1, has_rw) ||
+ !check_caller_access_to_name(new_dir, new_dentry->d_name.name,
+ sbi->options.derive, 1, has_rw)) {
+ printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
+ " new_dentry: %s, task:%s\n",
+ __func__, new_dentry->d_name.name, current->comm);
+ err = -EACCES;
+ goto out_eacces;
+ }
+
+ /* save current_cred and override it */
+ OVERRIDE_CRED(SDCARDFS_SB(old_dir->i_sb), saved_cred);
+
+ sdcardfs_get_real_lower(old_dentry, &lower_old_path);
+ sdcardfs_get_lower_path(new_dentry, &lower_new_path);
+ lower_old_dentry = lower_old_path.dentry;
+ lower_new_dentry = lower_new_path.dentry;
+ lower_old_dir_dentry = dget_parent(lower_old_dentry);
+ lower_new_dir_dentry = dget_parent(lower_new_dentry);
+
+ trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+ /* source should not be ancestor of target */
+ if (trap == lower_old_dentry) {
+ err = -EINVAL;
+ goto out;
+ }
+ /* target should not be ancestor of source */
+ if (trap == lower_new_dentry) {
+ err = -ENOTEMPTY;
+ goto out;
+ }
+
+ err = mnt_want_write(lower_old_path.mnt);
+ if (err)
+ goto out;
+ err = mnt_want_write(lower_new_path.mnt);
+ if (err)
+ goto out_drop_old_write;
+
+ err = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
+ lower_new_dir_dentry->d_inode, lower_new_dentry);
+ if (err)
+ goto out_err;
+
+ /* Copy attrs from lower dir, but i_uid/i_gid */
+ fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
+ fsstack_copy_inode_size(new_dir, lower_new_dir_dentry->d_inode);
+ fix_derived_permission(new_dir);
+ if (new_dir != old_dir) {
+ fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
+ fsstack_copy_inode_size(old_dir, lower_old_dir_dentry->d_inode);
+ fix_derived_permission(old_dir);
+ /* update the derived permission of the old_dentry
+ * with its new parent
+ */
+ new_parent = dget_parent(new_dentry);
+ if(new_parent) {
+ if(old_dentry->d_inode) {
+ get_derived_permission(new_parent, old_dentry);
+ fix_derived_permission(old_dentry->d_inode);
+ }
+ dput(new_parent);
+ }
+ }
+
+out_err:
+ mnt_drop_write(lower_new_path.mnt);
+out_drop_old_write:
+ mnt_drop_write(lower_old_path.mnt);
+out:
+ unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
+ dput(lower_old_dir_dentry);
+ dput(lower_new_dir_dentry);
+ sdcardfs_put_real_lower(old_dentry, &lower_old_path);
+ sdcardfs_put_lower_path(new_dentry, &lower_new_path);
+ REVERT_CRED(saved_cred);
+out_eacces:
+ return err;
+}
+
+#if 0
+static int sdcardfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
+{
+ int err;
+ struct dentry *lower_dentry;
+ struct path lower_path;
+ /* XXX readlink does not requires overriding credential */
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ if (!lower_dentry->d_inode->i_op ||
+ !lower_dentry->d_inode->i_op->readlink) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ err = lower_dentry->d_inode->i_op->readlink(lower_dentry,
+ buf, bufsiz);
+ if (err < 0)
+ goto out;
+ fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
+
+out:
+ sdcardfs_put_lower_path(dentry, &lower_path);
+ return err;
+}
+#endif
+
+#if 0
+static void *sdcardfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ char *buf;
+ int len = PAGE_SIZE, err;
+ mm_segment_t old_fs;
+
+ /* This is freed by the put_link method assuming a successful call. */
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf) {
+ buf = ERR_PTR(-ENOMEM);
+ goto out;
+ }
+
+ /* read the symlink, and then we will follow it */
+ old_fs = get_fs();
+ set_fs(KERNEL_DS);
+ err = sdcardfs_readlink(dentry, buf, len);
+ set_fs(old_fs);
+ if (err < 0) {
+ kfree(buf);
+ buf = ERR_PTR(err);
+ } else {
+ buf[err] = '\0';
+ }
+out:
+ nd_set_link(nd, buf);
+ return NULL;
+}
+#endif
+
+#if 0
+/* this @nd *IS* still used */
+static void sdcardfs_put_link(struct dentry *dentry, struct nameidata *nd,
+ void *cookie)
+{
+ char *buf = nd_get_link(nd);
+ if (!IS_ERR(buf)) /* free the char* */
+ kfree(buf);
+}
+#endif
+
+static int sdcardfs_permission(struct inode *inode, int mask, unsigned int flags)
+{
+ int err;
+
+ if (flags & IPERM_FLAG_RCU)
+ return -ECHILD;
+
+ /*
+ * Permission check on sdcardfs inode.
+ * Calling process should have AID_SDCARD_RW permission
+ */
+ err = generic_permission(inode, mask, 0, inode->i_op->check_acl);
+
+ /* XXX
+ * Original sdcardfs code calls inode_permission(lower_inode,.. )
+ * for checking inode permission. But doing such things here seems
+ * duplicated work, because the functions called after this func,
+ * such as vfs_create, vfs_unlink, vfs_rename, and etc,
+ * does exactly same thing, i.e., they calls inode_permission().
+ * So we just let they do the things.
+ * If there are any security hole, just uncomment following if block.
+ */
+#if 0
+ if (!err) {
+ /*
+ * Permission check on lower_inode(=EXT4).
+ * we check it with AID_MEDIA_RW permission
+ */
+ struct inode *lower_inode;
+ OVERRIDE_CRED(SDCARDFS_SB(inode->sb));
+
+ lower_inode = sdcardfs_lower_inode(inode);
+ err = inode_permission(lower_inode, mask);
+
+ REVERT_CRED();
+ }
+#endif
+ return err;
+
+}
+
+static int sdcardfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
+ struct kstat *stat)
+{
+ struct dentry *lower_dentry;
+ struct inode *inode;
+ struct inode *lower_inode;
+ struct path lower_path;
+ struct dentry *parent;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+
+ parent = dget_parent(dentry);
+ if(!check_caller_access_to_name(parent->d_inode, dentry->d_name.name,
+ sbi->options.derive, 0, 0)) {
+ printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
+ " dentry: %s, task:%s\n",
+ __func__, dentry->d_name.name, current->comm);
+ dput(parent);
+ return -EACCES;
+ }
+ dput(parent);
+
+ inode = dentry->d_inode;
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ lower_inode = sdcardfs_lower_inode(inode);
+
+ fsstack_copy_attr_all(inode, lower_inode);
+ fsstack_copy_inode_size(inode, lower_inode);
+ /* if the dentry has been moved from other location
+ * so, on this stage, its derived permission must be
+ * rechecked from its private field.
+ */
+ fix_derived_permission(inode);
+
+ generic_fillattr(inode, stat);
+ sdcardfs_put_lower_path(dentry, &lower_path);
+ return 0;
+}
+
+static int sdcardfs_setattr(struct dentry *dentry, struct iattr *ia)
+{
+ int err = 0;
+ struct dentry *lower_dentry;
+ struct inode *inode;
+ struct inode *lower_inode;
+ struct path lower_path;
+ struct iattr lower_ia;
+ struct sdcardfs_sb_info *sbi = SDCARDFS_SB(dentry->d_sb);
+ struct dentry *parent;
+ int has_rw;
+
+ inode = dentry->d_inode;
+
+ /*
+ * Check if user has permission to change inode. We don't check if
+ * this user can change the lower inode: that should happen when
+ * calling notify_change on the lower inode.
+ */
+ err = inode_change_ok(inode, ia);
+
+ /* no vfs_XXX operations required, cred overriding will be skipped. wj*/
+ if (!err) {
+ /* check the Android group ID */
+ has_rw = get_caller_has_rw_locked(sbi->pkgl_id, sbi->options.derive);
+ parent = dget_parent(dentry);
+ if(!check_caller_access_to_name(parent->d_inode, dentry->d_name.name,
+ sbi->options.derive, 1, has_rw)) {
+ printk(KERN_INFO "%s: need to check the caller's gid in packages.list\n"
+ " dentry: %s, task:%s\n",
+ __func__, dentry->d_name.name, current->comm);
+ err = -EACCES;
+ }
+ dput(parent);
+ }
+
+ if (err)
+ goto out_err;
+
+ sdcardfs_get_lower_path(dentry, &lower_path);
+ lower_dentry = lower_path.dentry;
+ lower_inode = sdcardfs_lower_inode(inode);
+
+ /* prepare our own lower struct iattr (with the lower file) */
+ memcpy(&lower_ia, ia, sizeof(lower_ia));
+ if (ia->ia_valid & ATTR_FILE)
+ lower_ia.ia_file = sdcardfs_lower_file(ia->ia_file);
+
+ lower_ia.ia_valid &= ~(ATTR_UID | ATTR_GID | ATTR_MODE);
+
+ /*
+ * If shrinking, first truncate upper level to cancel writing dirty
+ * pages beyond the new eof; and also if its' maxbytes is more
+ * limiting (fail with -EFBIG before making any change to the lower
+ * level). There is no need to vmtruncate the upper level
+ * afterwards in the other cases: we fsstack_copy_inode_size from
+ * the lower level.
+ */
+ if (current->mm)
+ down_write(¤t->mm->mmap_sem);
+ if (ia->ia_valid & ATTR_SIZE) {
+ err = inode_newsize_ok(inode, ia->ia_size);
+ if (err) {
+ if (current->mm)
+ up_write(¤t->mm->mmap_sem);
+ goto out;
+ }
+ truncate_setsize(inode, ia->ia_size);
+ }
+
+ /*
+ * mode change is for clearing setuid/setgid bits. Allow lower fs
+ * to interpret this in its own way.
+ */
+ if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
+ lower_ia.ia_valid &= ~ATTR_MODE;
+
+ /* notify the (possibly copied-up) lower inode */
+ /*
+ * Note: we use lower_dentry->d_inode, because lower_inode may be
+ * unlinked (no inode->i_sb and i_ino==0. This happens if someone
+ * tries to open(), unlink(), then ftruncate() a file.
+ */
+ mutex_lock(&lower_dentry->d_inode->i_mutex);
+ err = notify_change(lower_dentry, &lower_ia); /* note: lower_ia */
+ mutex_unlock(&lower_dentry->d_inode->i_mutex);
+ if (current->mm)
+ up_write(¤t->mm->mmap_sem);
+ if (err)
+ goto out;
+
+ /* get attributes from the lower inode */
+ fsstack_copy_attr_all(inode, lower_inode);
+ /* update derived permission of the upper inode */
+ fix_derived_permission(inode);
+
+ /*
+ * Not running fsstack_copy_inode_size(inode, lower_inode), because
+ * VFS should update our inode size, and notify_change on
+ * lower_inode should update its size.
+ */
+
+out:
+ sdcardfs_put_lower_path(dentry, &lower_path);
+out_err:
+ return err;
+}
+
+const struct inode_operations sdcardfs_symlink_iops = {
+ .permission = sdcardfs_permission,
+ .setattr = sdcardfs_setattr,
+ /* XXX Following operations are implemented,
+ * but FUSE(sdcard) or FAT does not support them
+ * These methods are *NOT* perfectly tested.
+ .readlink = sdcardfs_readlink,
+ .follow_link = sdcardfs_follow_link,
+ .put_link = sdcardfs_put_link,
+ */
+};
+
+const struct inode_operations sdcardfs_dir_iops = {
+ .create = sdcardfs_create,
+ .lookup = sdcardfs_lookup,
+ .permission = sdcardfs_permission,
+ .unlink = sdcardfs_unlink,
+ .mkdir = sdcardfs_mkdir,
+ .rmdir = sdcardfs_rmdir,
+ .rename = sdcardfs_rename,
+ .setattr = sdcardfs_setattr,
+ .getattr = sdcardfs_getattr,
+ /* XXX Following operations are implemented,
+ * but FUSE(sdcard) or FAT does not support them
+ * These methods are *NOT* perfectly tested.
+ .symlink = sdcardfs_symlink,
+ .link = sdcardfs_link,
+ .mknod = sdcardfs_mknod,
+ */
+};
+
+const struct inode_operations sdcardfs_main_iops = {
+ .permission = sdcardfs_permission,
+ .setattr = sdcardfs_setattr,
+ .getattr = sdcardfs_getattr,
+};