| 1 | // SPDX-License-Identifier: GPL-2.0+ |
| 2 | /* |
| 3 | * NILFS regular file handling primitives including fsync(). |
| 4 | * |
| 5 | * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. |
| 6 | * |
| 7 | * Written by Amagai Yoshiji and Ryusuke Konishi. |
| 8 | */ |
| 9 | |
| 10 | #include <linux/fs.h> |
| 11 | #include <linux/mm.h> |
| 12 | #include <linux/writeback.h> |
| 13 | #include "nilfs.h" |
| 14 | #include "segment.h" |
| 15 | |
| 16 | int nilfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) |
| 17 | { |
| 18 | /* |
| 19 | * Called from fsync() system call |
| 20 | * This is the only entry point that can catch write and synch |
| 21 | * timing for both data blocks and intermediate blocks. |
| 22 | * |
| 23 | * This function should be implemented when the writeback function |
| 24 | * will be implemented. |
| 25 | */ |
| 26 | struct the_nilfs *nilfs; |
| 27 | struct inode *inode = file->f_mapping->host; |
| 28 | int err = 0; |
| 29 | |
| 30 | if (nilfs_inode_dirty(inode)) { |
| 31 | if (datasync) |
| 32 | err = nilfs_construct_dsync_segment(inode->i_sb, inode, |
| 33 | start, end); |
| 34 | else |
| 35 | err = nilfs_construct_segment(inode->i_sb); |
| 36 | } |
| 37 | |
| 38 | nilfs = inode->i_sb->s_fs_info; |
| 39 | if (!err) |
| 40 | err = nilfs_flush_device(nilfs); |
| 41 | |
| 42 | return err; |
| 43 | } |
| 44 | |
| 45 | static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf) |
| 46 | { |
| 47 | struct vm_area_struct *vma = vmf->vma; |
| 48 | struct folio *folio = page_folio(vmf->page); |
| 49 | struct inode *inode = file_inode(vma->vm_file); |
| 50 | struct nilfs_transaction_info ti; |
| 51 | struct buffer_head *bh, *head; |
| 52 | int ret = 0; |
| 53 | |
| 54 | if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info))) |
| 55 | return VM_FAULT_SIGBUS; /* -ENOSPC */ |
| 56 | |
| 57 | sb_start_pagefault(inode->i_sb); |
| 58 | folio_lock(folio); |
| 59 | if (folio->mapping != inode->i_mapping || |
| 60 | folio_pos(folio) >= i_size_read(inode) || |
| 61 | !folio_test_uptodate(folio)) { |
| 62 | folio_unlock(folio); |
| 63 | ret = -EFAULT; /* make the VM retry the fault */ |
| 64 | goto out; |
| 65 | } |
| 66 | |
| 67 | /* |
| 68 | * check to see if the folio is mapped already (no holes) |
| 69 | */ |
| 70 | if (folio_test_mappedtodisk(folio)) |
| 71 | goto mapped; |
| 72 | |
| 73 | head = folio_buffers(folio); |
| 74 | if (head) { |
| 75 | int fully_mapped = 1; |
| 76 | |
| 77 | bh = head; |
| 78 | do { |
| 79 | if (!buffer_mapped(bh)) { |
| 80 | fully_mapped = 0; |
| 81 | break; |
| 82 | } |
| 83 | } while (bh = bh->b_this_page, bh != head); |
| 84 | |
| 85 | if (fully_mapped) { |
| 86 | folio_set_mappedtodisk(folio); |
| 87 | goto mapped; |
| 88 | } |
| 89 | } |
| 90 | folio_unlock(folio); |
| 91 | |
| 92 | /* |
| 93 | * fill hole blocks |
| 94 | */ |
| 95 | ret = nilfs_transaction_begin(inode->i_sb, &ti, 1); |
| 96 | /* never returns -ENOMEM, but may return -ENOSPC */ |
| 97 | if (unlikely(ret)) |
| 98 | goto out; |
| 99 | |
| 100 | file_update_time(vma->vm_file); |
| 101 | ret = block_page_mkwrite(vma, vmf, nilfs_get_block); |
| 102 | if (ret) { |
| 103 | nilfs_transaction_abort(inode->i_sb); |
| 104 | goto out; |
| 105 | } |
| 106 | nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits)); |
| 107 | nilfs_transaction_commit(inode->i_sb); |
| 108 | |
| 109 | mapped: |
| 110 | /* |
| 111 | * Since checksumming including data blocks is performed to determine |
| 112 | * the validity of the log to be written and used for recovery, it is |
| 113 | * necessary to wait for writeback to finish here, regardless of the |
| 114 | * stable write requirement of the backing device. |
| 115 | */ |
| 116 | folio_wait_writeback(folio); |
| 117 | out: |
| 118 | sb_end_pagefault(inode->i_sb); |
| 119 | return vmf_fs_error(ret); |
| 120 | } |
| 121 | |
| 122 | static const struct vm_operations_struct nilfs_file_vm_ops = { |
| 123 | .fault = filemap_fault, |
| 124 | .map_pages = filemap_map_pages, |
| 125 | .page_mkwrite = nilfs_page_mkwrite, |
| 126 | }; |
| 127 | |
| 128 | static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma) |
| 129 | { |
| 130 | file_accessed(file); |
| 131 | vma->vm_ops = &nilfs_file_vm_ops; |
| 132 | return 0; |
| 133 | } |
| 134 | |
| 135 | /* |
| 136 | * We have mostly NULL's here: the current defaults are ok for |
| 137 | * the nilfs filesystem. |
| 138 | */ |
| 139 | const struct file_operations nilfs_file_operations = { |
| 140 | .llseek = generic_file_llseek, |
| 141 | .read_iter = generic_file_read_iter, |
| 142 | .write_iter = generic_file_write_iter, |
| 143 | .unlocked_ioctl = nilfs_ioctl, |
| 144 | #ifdef CONFIG_COMPAT |
| 145 | .compat_ioctl = nilfs_compat_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 = filemap_splice_read, |
| 152 | .splice_write = iter_file_splice_write, |
| 153 | }; |
| 154 | |
| 155 | const struct inode_operations nilfs_file_inode_operations = { |
| 156 | .setattr = nilfs_setattr, |
| 157 | .permission = nilfs_permission, |
| 158 | .fiemap = nilfs_fiemap, |
| 159 | .fileattr_get = nilfs_fileattr_get, |
| 160 | .fileattr_set = nilfs_fileattr_set, |
| 161 | }; |
| 162 | |
| 163 | /* end of file */ |