1 /* 2 * file.c - NILFS regular file handling primitives including fsync(). 3 * 4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * Written by Amagai Yoshiji and Ryusuke Konishi. 17 */ 18 19 #include <linux/fs.h> 20 #include <linux/mm.h> 21 #include <linux/writeback.h> 22 #include "nilfs.h" 23 #include "segment.h" 24 25 int nilfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) 26 { 27 /* 28 * Called from fsync() system call 29 * This is the only entry point that can catch write and synch 30 * timing for both data blocks and intermediate blocks. 31 * 32 * This function should be implemented when the writeback function 33 * will be implemented. 34 */ 35 struct the_nilfs *nilfs; 36 struct inode *inode = file->f_mapping->host; 37 int err = 0; 38 39 if (nilfs_inode_dirty(inode)) { 40 if (datasync) 41 err = nilfs_construct_dsync_segment(inode->i_sb, inode, 42 start, end); 43 else 44 err = nilfs_construct_segment(inode->i_sb); 45 } 46 47 nilfs = inode->i_sb->s_fs_info; 48 if (!err) 49 err = nilfs_flush_device(nilfs); 50 51 return err; 52 } 53 54 static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 55 { 56 struct page *page = vmf->page; 57 struct inode *inode = file_inode(vma->vm_file); 58 struct nilfs_transaction_info ti; 59 int ret = 0; 60 61 if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info))) 62 return VM_FAULT_SIGBUS; /* -ENOSPC */ 63 64 sb_start_pagefault(inode->i_sb); 65 lock_page(page); 66 if (page->mapping != inode->i_mapping || 67 page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) { 68 unlock_page(page); 69 ret = -EFAULT; /* make the VM retry the fault */ 70 goto out; 71 } 72 73 /* 74 * check to see if the page is mapped already (no holes) 75 */ 76 if (PageMappedToDisk(page)) 77 goto mapped; 78 79 if (page_has_buffers(page)) { 80 struct buffer_head *bh, *head; 81 int fully_mapped = 1; 82 83 bh = head = page_buffers(page); 84 do { 85 if (!buffer_mapped(bh)) { 86 fully_mapped = 0; 87 break; 88 } 89 } while (bh = bh->b_this_page, bh != head); 90 91 if (fully_mapped) { 92 SetPageMappedToDisk(page); 93 goto mapped; 94 } 95 } 96 unlock_page(page); 97 98 /* 99 * fill hole blocks 100 */ 101 ret = nilfs_transaction_begin(inode->i_sb, &ti, 1); 102 /* never returns -ENOMEM, but may return -ENOSPC */ 103 if (unlikely(ret)) 104 goto out; 105 106 file_update_time(vma->vm_file); 107 ret = block_page_mkwrite(vma, vmf, nilfs_get_block); 108 if (ret) { 109 nilfs_transaction_abort(inode->i_sb); 110 goto out; 111 } 112 nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits)); 113 nilfs_transaction_commit(inode->i_sb); 114 115 mapped: 116 wait_for_stable_page(page); 117 out: 118 sb_end_pagefault(inode->i_sb); 119 return block_page_mkwrite_return(ret); 120 } 121 122 static const struct vm_operations_struct nilfs_file_vm_ops = { 123 .fault = filemap_fault, 124 .map_pages = filemap_map_pages, 125 .page_mkwrite = nilfs_page_mkwrite, 126 }; 127 128 static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma) 129 { 130 file_accessed(file); 131 vma->vm_ops = &nilfs_file_vm_ops; 132 return 0; 133 } 134 135 /* 136 * We have mostly NULL's here: the current defaults are ok for 137 * the nilfs filesystem. 138 */ 139 const struct file_operations nilfs_file_operations = { 140 .llseek = generic_file_llseek, 141 .read_iter = generic_file_read_iter, 142 .write_iter = generic_file_write_iter, 143 .unlocked_ioctl = nilfs_ioctl, 144 #ifdef CONFIG_COMPAT 145 .compat_ioctl = nilfs_compat_ioctl, 146 #endif /* CONFIG_COMPAT */ 147 .mmap = nilfs_file_mmap, 148 .open = generic_file_open, 149 /* .release = nilfs_release_file, */ 150 .fsync = nilfs_sync_file, 151 .splice_read = generic_file_splice_read, 152 }; 153 154 const struct inode_operations nilfs_file_inode_operations = { 155 .setattr = nilfs_setattr, 156 .permission = nilfs_permission, 157 .fiemap = nilfs_fiemap, 158 }; 159 160 /* end of file */ 161