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 = 0; 43 44 if (nilfs_inode_dirty(inode)) { 45 if (datasync) 46 err = nilfs_construct_dsync_segment(inode->i_sb, inode, 47 start, end); 48 else 49 err = nilfs_construct_segment(inode->i_sb); 50 } 51 52 nilfs = inode->i_sb->s_fs_info; 53 if (!err) 54 err = nilfs_flush_device(nilfs); 55 56 return err; 57 } 58 59 static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 60 { 61 struct page *page = vmf->page; 62 struct inode *inode = file_inode(vma->vm_file); 63 struct nilfs_transaction_info ti; 64 int ret = 0; 65 66 if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info))) 67 return VM_FAULT_SIGBUS; /* -ENOSPC */ 68 69 sb_start_pagefault(inode->i_sb); 70 lock_page(page); 71 if (page->mapping != inode->i_mapping || 72 page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) { 73 unlock_page(page); 74 ret = -EFAULT; /* make the VM retry the fault */ 75 goto out; 76 } 77 78 /* 79 * check to see if the page is mapped already (no holes) 80 */ 81 if (PageMappedToDisk(page)) 82 goto mapped; 83 84 if (page_has_buffers(page)) { 85 struct buffer_head *bh, *head; 86 int fully_mapped = 1; 87 88 bh = head = page_buffers(page); 89 do { 90 if (!buffer_mapped(bh)) { 91 fully_mapped = 0; 92 break; 93 } 94 } while (bh = bh->b_this_page, bh != head); 95 96 if (fully_mapped) { 97 SetPageMappedToDisk(page); 98 goto mapped; 99 } 100 } 101 unlock_page(page); 102 103 /* 104 * fill hole blocks 105 */ 106 ret = nilfs_transaction_begin(inode->i_sb, &ti, 1); 107 /* never returns -ENOMEM, but may return -ENOSPC */ 108 if (unlikely(ret)) 109 goto out; 110 111 file_update_time(vma->vm_file); 112 ret = block_page_mkwrite(vma, vmf, nilfs_get_block); 113 if (ret) { 114 nilfs_transaction_abort(inode->i_sb); 115 goto out; 116 } 117 nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits)); 118 nilfs_transaction_commit(inode->i_sb); 119 120 mapped: 121 wait_for_stable_page(page); 122 out: 123 sb_end_pagefault(inode->i_sb); 124 return block_page_mkwrite_return(ret); 125 } 126 127 static const struct vm_operations_struct nilfs_file_vm_ops = { 128 .fault = filemap_fault, 129 .map_pages = filemap_map_pages, 130 .page_mkwrite = nilfs_page_mkwrite, 131 }; 132 133 static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma) 134 { 135 file_accessed(file); 136 vma->vm_ops = &nilfs_file_vm_ops; 137 return 0; 138 } 139 140 /* 141 * We have mostly NULL's here: the current defaults are ok for 142 * the nilfs filesystem. 143 */ 144 const struct file_operations nilfs_file_operations = { 145 .llseek = generic_file_llseek, 146 .read_iter = generic_file_read_iter, 147 .write_iter = generic_file_write_iter, 148 .unlocked_ioctl = nilfs_ioctl, 149 #ifdef CONFIG_COMPAT 150 .compat_ioctl = nilfs_compat_ioctl, 151 #endif /* CONFIG_COMPAT */ 152 .mmap = nilfs_file_mmap, 153 .open = generic_file_open, 154 /* .release = nilfs_release_file, */ 155 .fsync = nilfs_sync_file, 156 .splice_read = generic_file_splice_read, 157 }; 158 159 const struct inode_operations nilfs_file_inode_operations = { 160 .setattr = nilfs_setattr, 161 .permission = nilfs_permission, 162 .fiemap = nilfs_fiemap, 163 }; 164 165 /* end of file */ 166