| 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 = do_sync_write, |
| 157 | .read_iter = generic_file_read_iter, |
| 158 | .aio_write = generic_file_aio_write, |
| 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 */ |