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 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 19 * 20 * Written by Amagai Yoshiji <amagai@osrg.net>, 21 * Ryusuke Konishi <ryusuke@osrg.net> 22 */ 23 24 #include <linux/fs.h> 25 #include <linux/mm.h> 26 #include <linux/writeback.h> 27 #include "nilfs.h" 28 #include "segment.h" 29 30 int nilfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) 31 { 32 /* 33 * Called from fsync() system call 34 * This is the only entry point that can catch write and synch 35 * timing for both data blocks and intermediate blocks. 36 * 37 * This function should be implemented when the writeback function 38 * will be implemented. 39 */ 40 struct the_nilfs *nilfs; 41 struct inode *inode = file->f_mapping->host; 42 int err; 43 44 err = filemap_write_and_wait_range(inode->i_mapping, start, end); 45 if (err) 46 return err; 47 mutex_lock(&inode->i_mutex); 48 49 if (nilfs_inode_dirty(inode)) { 50 if (datasync) 51 err = nilfs_construct_dsync_segment(inode->i_sb, inode, 52 0, LLONG_MAX); 53 else 54 err = nilfs_construct_segment(inode->i_sb); 55 } 56 mutex_unlock(&inode->i_mutex); 57 58 nilfs = inode->i_sb->s_fs_info; 59 if (!err && nilfs_test_opt(nilfs, BARRIER)) { 60 err = blkdev_issue_flush(inode->i_sb->s_bdev, GFP_KERNEL, NULL); 61 if (err != -EIO) 62 err = 0; 63 } 64 return err; 65 } 66 67 static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 68 { 69 struct page *page = vmf->page; 70 struct inode *inode = file_inode(vma->vm_file); 71 struct nilfs_transaction_info ti; 72 int ret = 0; 73 74 if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info))) 75 return VM_FAULT_SIGBUS; /* -ENOSPC */ 76 77 sb_start_pagefault(inode->i_sb); 78 lock_page(page); 79 if (page->mapping != inode->i_mapping || 80 page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) { 81 unlock_page(page); 82 ret = -EFAULT; /* make the VM retry the fault */ 83 goto out; 84 } 85 86 /* 87 * check to see if the page is mapped already (no holes) 88 */ 89 if (PageMappedToDisk(page)) 90 goto mapped; 91 92 if (page_has_buffers(page)) { 93 struct buffer_head *bh, *head; 94 int fully_mapped = 1; 95 96 bh = head = page_buffers(page); 97 do { 98 if (!buffer_mapped(bh)) { 99 fully_mapped = 0; 100 break; 101 } 102 } while (bh = bh->b_this_page, bh != head); 103 104 if (fully_mapped) { 105 SetPageMappedToDisk(page); 106 goto mapped; 107 } 108 } 109 unlock_page(page); 110 111 /* 112 * fill hole blocks 113 */ 114 ret = nilfs_transaction_begin(inode->i_sb, &ti, 1); 115 /* never returns -ENOMEM, but may return -ENOSPC */ 116 if (unlikely(ret)) 117 goto out; 118 119 file_update_time(vma->vm_file); 120 ret = __block_page_mkwrite(vma, vmf, nilfs_get_block); 121 if (ret) { 122 nilfs_transaction_abort(inode->i_sb); 123 goto out; 124 } 125 nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits)); 126 nilfs_transaction_commit(inode->i_sb); 127 128 mapped: 129 wait_for_stable_page(page); 130 out: 131 sb_end_pagefault(inode->i_sb); 132 return block_page_mkwrite_return(ret); 133 } 134 135 static const struct vm_operations_struct nilfs_file_vm_ops = { 136 .fault = filemap_fault, 137 .map_pages = filemap_map_pages, 138 .page_mkwrite = nilfs_page_mkwrite, 139 .remap_pages = generic_file_remap_pages, 140 }; 141 142 static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma) 143 { 144 file_accessed(file); 145 vma->vm_ops = &nilfs_file_vm_ops; 146 return 0; 147 } 148 149 /* 150 * We have mostly NULL's here: the current defaults are ok for 151 * the nilfs filesystem. 152 */ 153 const struct file_operations nilfs_file_operations = { 154 .llseek = generic_file_llseek, 155 .read = new_sync_read, 156 .write = new_sync_write, 157 .read_iter = generic_file_read_iter, 158 .write_iter = generic_file_write_iter, 159 .unlocked_ioctl = nilfs_ioctl, 160 #ifdef CONFIG_COMPAT 161 .compat_ioctl = nilfs_compat_ioctl, 162 #endif /* CONFIG_COMPAT */ 163 .mmap = nilfs_file_mmap, 164 .open = generic_file_open, 165 /* .release = nilfs_release_file, */ 166 .fsync = nilfs_sync_file, 167 .splice_read = generic_file_splice_read, 168 }; 169 170 const struct inode_operations nilfs_file_inode_operations = { 171 .setattr = nilfs_setattr, 172 .permission = nilfs_permission, 173 .fiemap = nilfs_fiemap, 174 }; 175 176 /* end of file */ 177