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/filelock.h> 12 #include <linux/mm.h> 13 #include <linux/writeback.h> 14 #include "nilfs.h" 15 #include "segment.h" 16 17 int nilfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) 18 { 19 /* 20 * Called from fsync() system call 21 * This is the only entry point that can catch write and synch 22 * timing for both data blocks and intermediate blocks. 23 * 24 * This function should be implemented when the writeback function 25 * will be implemented. 26 */ 27 struct the_nilfs *nilfs; 28 struct inode *inode = file->f_mapping->host; 29 int err = 0; 30 31 if (nilfs_inode_dirty(inode)) { 32 if (datasync) 33 err = nilfs_construct_dsync_segment(inode->i_sb, inode, 34 start, end); 35 else 36 err = nilfs_construct_segment(inode->i_sb); 37 } 38 39 nilfs = inode->i_sb->s_fs_info; 40 if (!err) 41 err = nilfs_flush_device(nilfs); 42 43 return err; 44 } 45 46 static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf) 47 { 48 struct vm_area_struct *vma = vmf->vma; 49 struct folio *folio = page_folio(vmf->page); 50 struct inode *inode = file_inode(vma->vm_file); 51 struct nilfs_transaction_info ti; 52 struct buffer_head *bh, *head; 53 int ret = 0; 54 55 if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info))) 56 return VM_FAULT_SIGBUS; /* -ENOSPC */ 57 58 sb_start_pagefault(inode->i_sb); 59 folio_lock(folio); 60 if (folio->mapping != inode->i_mapping || 61 folio_pos(folio) >= i_size_read(inode) || 62 !folio_test_uptodate(folio)) { 63 folio_unlock(folio); 64 ret = -EFAULT; /* make the VM retry the fault */ 65 goto out; 66 } 67 68 /* 69 * check to see if the folio is mapped already (no holes) 70 */ 71 if (folio_test_mappedtodisk(folio)) 72 goto mapped; 73 74 head = folio_buffers(folio); 75 if (head) { 76 int fully_mapped = 1; 77 78 bh = head; 79 do { 80 if (!buffer_mapped(bh)) { 81 fully_mapped = 0; 82 break; 83 } 84 } while (bh = bh->b_this_page, bh != head); 85 86 if (fully_mapped) { 87 folio_set_mappedtodisk(folio); 88 goto mapped; 89 } 90 } 91 folio_unlock(folio); 92 93 /* 94 * fill hole blocks 95 */ 96 ret = nilfs_transaction_begin(inode->i_sb, &ti, 1); 97 /* never returns -ENOMEM, but may return -ENOSPC */ 98 if (unlikely(ret)) 99 goto out; 100 101 file_update_time(vma->vm_file); 102 ret = block_page_mkwrite(vma, vmf, nilfs_get_block); 103 if (ret) { 104 nilfs_transaction_abort(inode->i_sb); 105 goto out; 106 } 107 nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits)); 108 nilfs_transaction_commit(inode->i_sb); 109 110 mapped: 111 /* 112 * Since checksumming including data blocks is performed to determine 113 * the validity of the log to be written and used for recovery, it is 114 * necessary to wait for writeback to finish here, regardless of the 115 * stable write requirement of the backing device. 116 */ 117 folio_wait_writeback(folio); 118 out: 119 sb_end_pagefault(inode->i_sb); 120 return vmf_fs_error(ret); 121 } 122 123 static const struct vm_operations_struct nilfs_file_vm_ops = { 124 .fault = filemap_fault, 125 .map_pages = filemap_map_pages, 126 .page_mkwrite = nilfs_page_mkwrite, 127 }; 128 129 static int nilfs_file_mmap_prepare(struct vm_area_desc *desc) 130 { 131 file_accessed(desc->file); 132 desc->vm_ops = &nilfs_file_vm_ops; 133 return 0; 134 } 135 136 /* 137 * We have mostly NULL's here: the current defaults are ok for 138 * the nilfs filesystem. 139 */ 140 const struct file_operations nilfs_file_operations = { 141 .llseek = generic_file_llseek, 142 .read_iter = generic_file_read_iter, 143 .write_iter = generic_file_write_iter, 144 .unlocked_ioctl = nilfs_ioctl, 145 #ifdef CONFIG_COMPAT 146 .compat_ioctl = nilfs_compat_ioctl, 147 #endif /* CONFIG_COMPAT */ 148 .mmap_prepare = nilfs_file_mmap_prepare, 149 .open = generic_file_open, 150 /* .release = nilfs_release_file, */ 151 .fsync = nilfs_sync_file, 152 .splice_read = filemap_splice_read, 153 .splice_write = iter_file_splice_write, 154 .setlease = generic_setlease, 155 }; 156 157 const struct inode_operations nilfs_file_inode_operations = { 158 .setattr = nilfs_setattr, 159 .permission = nilfs_permission, 160 .fiemap = nilfs_fiemap, 161 .fileattr_get = nilfs_fileattr_get, 162 .fileattr_set = nilfs_fileattr_set, 163 }; 164 165 /* end of file */ 166