/* * file.c - NILFS regular file handling primitives including fsync(). * * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * Written by Amagai Yoshiji <amagai@osrg.net>, * Ryusuke Konishi <ryusuke@osrg.net> */ #include <linux/fs.h> #include <linux/mm.h> #include <linux/writeback.h> #include "nilfs.h" #include "segment.h" int nilfs_sync_file(struct file *file, int datasync) { /* * Called from fsync() system call * This is the only entry point that can catch write and synch * timing for both data blocks and intermediate blocks. * * This function should be implemented when the writeback function * will be implemented. */ struct inode *inode = file->f_mapping->host; int err; if (!nilfs_inode_dirty(inode)) return 0; if (datasync) err = nilfs_construct_dsync_segment(inode->i_sb, inode, 0, LLONG_MAX); else err = nilfs_construct_segment(inode->i_sb); return err; } static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) { struct page *page = vmf->page; struct inode *inode = vma->vm_file->f_dentry->d_inode; struct nilfs_transaction_info ti; int ret; if (unlikely(nilfs_near_disk_full(NILFS_SB(inode->i_sb)->s_nilfs))) return VM_FAULT_SIGBUS; /* -ENOSPC */ lock_page(page); if (page->mapping != inode->i_mapping || page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) { unlock_page(page); return VM_FAULT_NOPAGE; /* make the VM retry the fault */ } /* * check to see if the page is mapped already (no holes) */ if (PageMappedToDisk(page)) { unlock_page(page); goto mapped; } if (page_has_buffers(page)) { struct buffer_head *bh, *head; int fully_mapped = 1; bh = head = page_buffers(page); do { if (!buffer_mapped(bh)) { fully_mapped = 0; break; } } while (bh = bh->b_this_page, bh != head); if (fully_mapped) { SetPageMappedToDisk(page); unlock_page(page); goto mapped; } } unlock_page(page); /* * fill hole blocks */ ret = nilfs_transaction_begin(inode->i_sb, &ti, 1); /* never returns -ENOMEM, but may return -ENOSPC */ if (unlikely(ret)) return VM_FAULT_SIGBUS; ret = block_page_mkwrite(vma, vmf, nilfs_get_block); if (unlikely(ret)) { nilfs_transaction_abort(inode->i_sb); return ret; } nilfs_transaction_commit(inode->i_sb); mapped: SetPageChecked(page); wait_on_page_writeback(page); return 0; } static const struct vm_operations_struct nilfs_file_vm_ops = { .fault = filemap_fault, .page_mkwrite = nilfs_page_mkwrite, }; static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma) { file_accessed(file); vma->vm_ops = &nilfs_file_vm_ops; vma->vm_flags |= VM_CAN_NONLINEAR; return 0; } /* * We have mostly NULL's here: the current defaults are ok for * the nilfs filesystem. */ const struct file_operations nilfs_file_operations = { .llseek = generic_file_llseek, .read = do_sync_read, .write = do_sync_write, .aio_read = generic_file_aio_read, .aio_write = generic_file_aio_write, .unlocked_ioctl = nilfs_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = nilfs_ioctl, #endif /* CONFIG_COMPAT */ .mmap = nilfs_file_mmap, .open = generic_file_open, /* .release = nilfs_release_file, */ .fsync = nilfs_sync_file, .splice_read = generic_file_splice_read, }; const struct inode_operations nilfs_file_inode_operations = { .truncate = nilfs_truncate, .setattr = nilfs_setattr, .permission = nilfs_permission, .fiemap = nilfs_fiemap, }; /* end of file */