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, 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 inode *inode = file->f_mapping->host; 41 int err; 42 43 if (!nilfs_inode_dirty(inode)) 44 return 0; 45 46 if (datasync) 47 err = nilfs_construct_dsync_segment(inode->i_sb, inode, 0, 48 LLONG_MAX); 49 else 50 err = nilfs_construct_segment(inode->i_sb); 51 52 return err; 53 } 54 55 static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 56 { 57 struct page *page = vmf->page; 58 struct inode *inode = vma->vm_file->f_dentry->d_inode; 59 struct nilfs_transaction_info ti; 60 int ret; 61 62 if (unlikely(nilfs_near_disk_full(NILFS_SB(inode->i_sb)->s_nilfs))) 63 return VM_FAULT_SIGBUS; /* -ENOSPC */ 64 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 return VM_FAULT_NOPAGE; /* make the VM retry the fault */ 70 } 71 72 /* 73 * check to see if the page is mapped already (no holes) 74 */ 75 if (PageMappedToDisk(page)) { 76 unlock_page(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 unlock_page(page); 94 goto mapped; 95 } 96 } 97 unlock_page(page); 98 99 /* 100 * fill hole blocks 101 */ 102 ret = nilfs_transaction_begin(inode->i_sb, &ti, 1); 103 /* never returns -ENOMEM, but may return -ENOSPC */ 104 if (unlikely(ret)) 105 return VM_FAULT_SIGBUS; 106 107 ret = block_page_mkwrite(vma, vmf, nilfs_get_block); 108 if (unlikely(ret)) { 109 nilfs_transaction_abort(inode->i_sb); 110 return ret; 111 } 112 nilfs_transaction_commit(inode->i_sb); 113 114 mapped: 115 SetPageChecked(page); 116 wait_on_page_writeback(page); 117 return 0; 118 } 119 120 static const struct vm_operations_struct nilfs_file_vm_ops = { 121 .fault = filemap_fault, 122 .page_mkwrite = nilfs_page_mkwrite, 123 }; 124 125 static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma) 126 { 127 file_accessed(file); 128 vma->vm_ops = &nilfs_file_vm_ops; 129 vma->vm_flags |= VM_CAN_NONLINEAR; 130 return 0; 131 } 132 133 /* 134 * We have mostly NULL's here: the current defaults are ok for 135 * the nilfs filesystem. 136 */ 137 const struct file_operations nilfs_file_operations = { 138 .llseek = generic_file_llseek, 139 .read = do_sync_read, 140 .write = do_sync_write, 141 .aio_read = generic_file_aio_read, 142 .aio_write = generic_file_aio_write, 143 .unlocked_ioctl = nilfs_ioctl, 144 #ifdef CONFIG_COMPAT 145 .compat_ioctl = nilfs_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 .truncate = nilfs_truncate, 156 .setattr = nilfs_setattr, 157 .permission = nilfs_permission, 158 }; 159 160 /* end of file */ 161