static int amfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) { int err; struct dentry *lower_dentry; struct dentry *lower_parent_dentry = NULL; struct path lower_path; amfs_get_lower_path(dentry, &lower_path); lower_dentry = lower_path.dentry; lower_parent_dentry = lock_parent(lower_dentry); err = vfs_mknod(lower_parent_dentry->d_inode, lower_dentry, mode, dev); if (err) goto out; err = amfs_interpose(dentry, dir->i_sb, &lower_path); if (err) goto out; fsstack_copy_attr_times(dir, amfs_lower_inode(dir)); fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode); out: unlock_dir(lower_parent_dentry); amfs_put_lower_path(dentry, &lower_path); return err; }
static int amfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { int err; struct dentry *lower_dentry; struct dentry *lower_parent_dentry = NULL; struct path lower_path; amfs_get_lower_path(dentry, &lower_path); lower_dentry = lower_path.dentry; lower_parent_dentry = lock_parent(lower_dentry); err = vfs_mkdir(lower_parent_dentry->d_inode, lower_dentry, mode); if (err) goto out; err = amfs_interpose(dentry, dir->i_sb, &lower_path); if (err) goto out; fsstack_copy_attr_times(dir, amfs_lower_inode(dir)); fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode); /* update number of links on parent directory */ set_nlink(dir, amfs_lower_inode(dir)->i_nlink); out: unlock_dir(lower_parent_dentry); amfs_put_lower_path(dentry, &lower_path); return err; }
static int amfs_symlink(struct inode *dir, struct dentry *dentry, const char *symname) { int err; struct dentry *lower_dentry; struct dentry *lower_parent_dentry = NULL; struct path lower_path; /* char* value = NULL; value = kzalloc(5,__GFP_WAIT); if(value==NULL){ err = -ENOMEM; goto out_err; } if(amfs_getxattr(dentry, AMFS_XATTR_NAME , value,5) > 0){ if(!strncmp(value,AMFS_BADFILE,3)){ err = -EPERM; goto freevalue; } }else if(amfs_getxattr(dentry, AMFS_XATTR_NAME, value, 5) != -ENODATA){ err = amfs_getxattr(dentry, AMFS_XATTR_NAME, value, 5); goto freevalue; } */ amfs_get_lower_path(dentry, &lower_path); lower_dentry = lower_path.dentry; lower_parent_dentry = lock_parent(lower_dentry); err = vfs_symlink(lower_parent_dentry->d_inode, lower_dentry, symname); if (err) goto out; err = amfs_interpose(dentry, dir->i_sb, &lower_path); if (err) goto out; fsstack_copy_attr_times(dir, amfs_lower_inode(dir)); fsstack_copy_inode_size(dir, lower_parent_dentry->d_inode); out: unlock_dir(lower_parent_dentry); amfs_put_lower_path(dentry, &lower_path); return err; }
static int amfs_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; char *value = NULL; if (old_dentry->d_inode->i_ino == AMFS_SB(old_dentry->d_sb)->inode_no) { err = -EPERM; goto out_err; } /************XATTR************/ value = kzalloc(5, __GFP_WAIT); if (value == NULL) { err = -ENOMEM; goto out_err; } if (amfs_getxattr(old_dentry, AMFS_XATTR_NAME, value, 5) > 0) { if (!strncmp(value, AMFS_BADFILE, 3)) { err = -EPERM; goto freevalue; } } else if (amfs_getxattr(old_dentry, AMFS_XATTR_NAME, value, 5) != -ENODATA){ err = amfs_getxattr(old_dentry, AMFS_XATTR_NAME, value, 5); goto freevalue; } /************XATTR***********/ file_size_save = i_size_read(old_dentry->d_inode); amfs_get_lower_path(old_dentry, &lower_old_path); amfs_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 = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode, lower_new_dentry, NULL); if (err || !lower_new_dentry->d_inode) goto out; err = amfs_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); set_nlink(old_dentry->d_inode, amfs_lower_inode(old_dentry->d_inode)->i_nlink); i_size_write(new_dentry->d_inode, file_size_save); out: unlock_dir(lower_dir_dentry); amfs_put_lower_path(old_dentry, &lower_old_path); amfs_put_lower_path(new_dentry, &lower_new_path); freevalue: kfree(value); out_err: return err; }
/* * Main driver function for amfs's lookup. * * Returns: NULL (ok), ERR_PTR if an error occurred. * Fills in lower_parent_path with <dentry,mnt> on success. */ static struct dentry *__amfs_lookup(struct dentry *dentry, unsigned int flags, struct path *lower_parent_path) { int err = 0; struct vfsmount *lower_dir_mnt; struct dentry *lower_dir_dentry = NULL; struct dentry *lower_dentry; const char *name; struct path lower_path; struct qstr this; /* must initialize dentry operations */ d_set_d_op(dentry, &amfs_dops); if (IS_ROOT(dentry)) goto out; name = dentry->d_name.name; /* now start the actual lookup procedure */ lower_dir_dentry = lower_parent_path->dentry; lower_dir_mnt = lower_parent_path->mnt; // printk("\n lookup.c-> struct dentry * _amfs_lookup"); //aditi /* Use vfs_path_lookup to check if the dentry exists or not */ err = vfs_path_lookup(lower_dir_dentry, lower_dir_mnt, name, 0, &lower_path); /* no error: handle positive dentries */ if (!err) { amfs_set_lower_path(dentry, &lower_path); err = amfs_interpose(dentry, dentry->d_sb, &lower_path); if (err) /* path_put underlying path on error */ amfs_put_reset_lower_path(dentry); goto out; } /* * We don't consider ENOENT an error, and we want to return a * negative dentry. */ if (err && err != -ENOENT) goto out; /* instatiate a new negative dentry */ this.name = name; this.len = strlen(name); this.hash = full_name_hash(this.name, this.len); lower_dentry = d_lookup(lower_dir_dentry, &this); if (lower_dentry) goto setup_lower; lower_dentry = d_alloc(lower_dir_dentry, &this); if (!lower_dentry) { err = -ENOMEM; goto out; } d_add(lower_dentry, NULL); /* instantiate and hash */ setup_lower: lower_path.dentry = lower_dentry; lower_path.mnt = mntget(lower_dir_mnt); amfs_set_lower_path(dentry, &lower_path); /* * If the intent is to create a file, then don't return an error, so * the VFS will continue the process of making this negative dentry * into a positive one. */ if (flags & (LOOKUP_CREATE|LOOKUP_RENAME_TARGET)) err = 0; out: return ERR_PTR(err); }