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) 60 err = nilfs_flush_device(nilfs); 61 62 return err; 63 } 64 65 static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 66 { 67 struct page *page = vmf->page; 68 struct inode *inode = file_inode(vma->vm_file); 69 struct nilfs_transaction_info ti; 70 int ret = 0; 71 72 if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info))) 73 return VM_FAULT_SIGBUS; /* -ENOSPC */ 74 75 sb_start_pagefault(inode->i_sb); 76 lock_page(page); 77 if (page->mapping != inode->i_mapping || 78 page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) { 79 unlock_page(page); 80 ret = -EFAULT; /* make the VM retry the fault */ 81 goto out; 82 } 83 84 /* 85 * check to see if the page is mapped already (no holes) 86 */ 87 if (PageMappedToDisk(page)) 88 goto mapped; 89 90 if (page_has_buffers(page)) { 91 struct buffer_head *bh, *head; 92 int fully_mapped = 1; 93 94 bh = head = page_buffers(page); 95 do { 96 if (!buffer_mapped(bh)) { 97 fully_mapped = 0; 98 break; 99 } 100 } while (bh = bh->b_this_page, bh != head); 101 102 if (fully_mapped) { 103 SetPageMappedToDisk(page); 104 goto mapped; 105 } 106 } 107 unlock_page(page); 108 109 /* 110 * fill hole blocks 111 */ 112 ret = nilfs_transaction_begin(inode->i_sb, &ti, 1); 113 /* never returns -ENOMEM, but may return -ENOSPC */ 114 if (unlikely(ret)) 115 goto out; 116 117 file_update_time(vma->vm_file); 118 ret = __block_page_mkwrite(vma, vmf, nilfs_get_block); 119 if (ret) { 120 nilfs_transaction_abort(inode->i_sb); 121 goto out; 122 } 123 nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits)); 124 nilfs_transaction_commit(inode->i_sb); 125 126 mapped: 127 wait_for_stable_page(page); 128 out: 129 sb_end_pagefault(inode->i_sb); 130 return block_page_mkwrite_return(ret); 131 } 132 133 static const struct vm_operations_struct nilfs_file_vm_ops = { 134 .fault = filemap_fault, 135 .map_pages = filemap_map_pages, 136 .page_mkwrite = nilfs_page_mkwrite, 137 .remap_pages = generic_file_remap_pages, 138 }; 139 140 static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma) 141 { 142 file_accessed(file); 143 vma->vm_ops = &nilfs_file_vm_ops; 144 return 0; 145 } 146 147 /* 148 * We have mostly NULL's here: the current defaults are ok for 149 * the nilfs filesystem. 150 */ 151 const struct file_operations nilfs_file_operations = { 152 .llseek = generic_file_llseek, 153 .read = new_sync_read, 154 .write = new_sync_write, 155 .read_iter = generic_file_read_iter, 156 .write_iter = generic_file_write_iter, 157 .unlocked_ioctl = nilfs_ioctl, 158 #ifdef CONFIG_COMPAT 159 .compat_ioctl = nilfs_compat_ioctl, 160 #endif /* CONFIG_COMPAT */ 161 .mmap = nilfs_file_mmap, 162 .open = generic_file_open, 163 /* .release = nilfs_release_file, */ 164 .fsync = nilfs_sync_file, 165 .splice_read = generic_file_splice_read, 166 }; 167 168 const struct inode_operations nilfs_file_inode_operations = { 169 .setattr = nilfs_setattr, 170 .permission = nilfs_permission, 171 .fiemap = nilfs_fiemap, 172 }; 173 174 /* end of file */ 175