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 inode *inode = file->f_mapping->host; 41 int err; 42 43 err = filemap_write_and_wait_range(inode->i_mapping, start, end); 44 if (err) 45 return err; 46 mutex_lock(&inode->i_mutex); 47 48 if (!nilfs_inode_dirty(inode)) { 49 mutex_unlock(&inode->i_mutex); 50 return 0; 51 } 52 53 if (datasync) 54 err = nilfs_construct_dsync_segment(inode->i_sb, inode, 0, 55 LLONG_MAX); 56 else 57 err = nilfs_construct_segment(inode->i_sb); 58 59 mutex_unlock(&inode->i_mutex); 60 return err; 61 } 62 63 static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 64 { 65 struct page *page = vmf->page; 66 struct inode *inode = vma->vm_file->f_dentry->d_inode; 67 struct nilfs_transaction_info ti; 68 int ret; 69 70 if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info))) 71 return VM_FAULT_SIGBUS; /* -ENOSPC */ 72 73 lock_page(page); 74 if (page->mapping != inode->i_mapping || 75 page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) { 76 unlock_page(page); 77 return VM_FAULT_NOPAGE; /* make the VM retry the fault */ 78 } 79 80 /* 81 * check to see if the page is mapped already (no holes) 82 */ 83 if (PageMappedToDisk(page)) 84 goto mapped; 85 86 if (page_has_buffers(page)) { 87 struct buffer_head *bh, *head; 88 int fully_mapped = 1; 89 90 bh = head = page_buffers(page); 91 do { 92 if (!buffer_mapped(bh)) { 93 fully_mapped = 0; 94 break; 95 } 96 } while (bh = bh->b_this_page, bh != head); 97 98 if (fully_mapped) { 99 SetPageMappedToDisk(page); 100 goto mapped; 101 } 102 } 103 unlock_page(page); 104 105 /* 106 * fill hole blocks 107 */ 108 ret = nilfs_transaction_begin(inode->i_sb, &ti, 1); 109 /* never returns -ENOMEM, but may return -ENOSPC */ 110 if (unlikely(ret)) 111 return VM_FAULT_SIGBUS; 112 113 ret = block_page_mkwrite(vma, vmf, nilfs_get_block); 114 if (ret != VM_FAULT_LOCKED) { 115 nilfs_transaction_abort(inode->i_sb); 116 return ret; 117 } 118 nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits)); 119 nilfs_transaction_commit(inode->i_sb); 120 121 mapped: 122 wait_on_page_writeback(page); 123 return VM_FAULT_LOCKED; 124 } 125 126 static const struct vm_operations_struct nilfs_file_vm_ops = { 127 .fault = filemap_fault, 128 .page_mkwrite = nilfs_page_mkwrite, 129 }; 130 131 static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma) 132 { 133 file_accessed(file); 134 vma->vm_ops = &nilfs_file_vm_ops; 135 vma->vm_flags |= VM_CAN_NONLINEAR; 136 return 0; 137 } 138 139 /* 140 * We have mostly NULL's here: the current defaults are ok for 141 * the nilfs filesystem. 142 */ 143 const struct file_operations nilfs_file_operations = { 144 .llseek = generic_file_llseek, 145 .read = do_sync_read, 146 .write = do_sync_write, 147 .aio_read = generic_file_aio_read, 148 .aio_write = generic_file_aio_write, 149 .unlocked_ioctl = nilfs_ioctl, 150 #ifdef CONFIG_COMPAT 151 .compat_ioctl = nilfs_compat_ioctl, 152 #endif /* CONFIG_COMPAT */ 153 .mmap = nilfs_file_mmap, 154 .open = generic_file_open, 155 /* .release = nilfs_release_file, */ 156 .fsync = nilfs_sync_file, 157 .splice_read = generic_file_splice_read, 158 }; 159 160 const struct inode_operations nilfs_file_inode_operations = { 161 .truncate = nilfs_truncate, 162 .setattr = nilfs_setattr, 163 .permission = nilfs_permission, 164 .fiemap = nilfs_fiemap, 165 }; 166 167 /* end of file */ 168