1 /* 2 * linux/fs/ext2/file.c 3 * 4 * Copyright (C) 1992, 1993, 1994, 1995 5 * Remy Card (card@masi.ibp.fr) 6 * Laboratoire MASI - Institut Blaise Pascal 7 * Universite Pierre et Marie Curie (Paris VI) 8 * 9 * from 10 * 11 * linux/fs/minix/file.c 12 * 13 * Copyright (C) 1991, 1992 Linus Torvalds 14 * 15 * ext2 fs regular file handling primitives 16 * 17 * 64-bit file support on 64-bit platforms by Jakub Jelinek 18 * (jj@sunsite.ms.mff.cuni.cz) 19 */ 20 21 #include <linux/time.h> 22 #include <linux/pagemap.h> 23 #include <linux/dax.h> 24 #include <linux/quotaops.h> 25 #include "ext2.h" 26 #include "xattr.h" 27 #include "acl.h" 28 29 #ifdef CONFIG_FS_DAX 30 /* 31 * The lock ordering for ext2 DAX fault paths is: 32 * 33 * mmap_sem (MM) 34 * sb_start_pagefault (vfs, freeze) 35 * ext2_inode_info->dax_sem 36 * address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX) 37 * ext2_inode_info->truncate_mutex 38 * 39 * The default page_lock and i_size verification done by non-DAX fault paths 40 * is sufficient because ext2 doesn't support hole punching. 41 */ 42 static int ext2_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf) 43 { 44 struct inode *inode = file_inode(vma->vm_file); 45 struct ext2_inode_info *ei = EXT2_I(inode); 46 int ret; 47 48 if (vmf->flags & FAULT_FLAG_WRITE) { 49 sb_start_pagefault(inode->i_sb); 50 file_update_time(vma->vm_file); 51 } 52 down_read(&ei->dax_sem); 53 54 ret = __dax_fault(vma, vmf, ext2_get_block, NULL); 55 56 up_read(&ei->dax_sem); 57 if (vmf->flags & FAULT_FLAG_WRITE) 58 sb_end_pagefault(inode->i_sb); 59 return ret; 60 } 61 62 static int ext2_dax_pmd_fault(struct vm_area_struct *vma, unsigned long addr, 63 pmd_t *pmd, unsigned int flags) 64 { 65 struct inode *inode = file_inode(vma->vm_file); 66 struct ext2_inode_info *ei = EXT2_I(inode); 67 int ret; 68 69 if (flags & FAULT_FLAG_WRITE) { 70 sb_start_pagefault(inode->i_sb); 71 file_update_time(vma->vm_file); 72 } 73 down_read(&ei->dax_sem); 74 75 ret = __dax_pmd_fault(vma, addr, pmd, flags, ext2_get_block, NULL); 76 77 up_read(&ei->dax_sem); 78 if (flags & FAULT_FLAG_WRITE) 79 sb_end_pagefault(inode->i_sb); 80 return ret; 81 } 82 83 static int ext2_dax_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 84 { 85 struct inode *inode = file_inode(vma->vm_file); 86 struct ext2_inode_info *ei = EXT2_I(inode); 87 int ret; 88 89 sb_start_pagefault(inode->i_sb); 90 file_update_time(vma->vm_file); 91 down_read(&ei->dax_sem); 92 93 ret = __dax_mkwrite(vma, vmf, ext2_get_block, NULL); 94 95 up_read(&ei->dax_sem); 96 sb_end_pagefault(inode->i_sb); 97 return ret; 98 } 99 100 static int ext2_dax_pfn_mkwrite(struct vm_area_struct *vma, 101 struct vm_fault *vmf) 102 { 103 struct inode *inode = file_inode(vma->vm_file); 104 struct ext2_inode_info *ei = EXT2_I(inode); 105 int ret = VM_FAULT_NOPAGE; 106 loff_t size; 107 108 sb_start_pagefault(inode->i_sb); 109 file_update_time(vma->vm_file); 110 down_read(&ei->dax_sem); 111 112 /* check that the faulting page hasn't raced with truncate */ 113 size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; 114 if (vmf->pgoff >= size) 115 ret = VM_FAULT_SIGBUS; 116 117 up_read(&ei->dax_sem); 118 sb_end_pagefault(inode->i_sb); 119 return ret; 120 } 121 122 static const struct vm_operations_struct ext2_dax_vm_ops = { 123 .fault = ext2_dax_fault, 124 .pmd_fault = ext2_dax_pmd_fault, 125 .page_mkwrite = ext2_dax_mkwrite, 126 .pfn_mkwrite = ext2_dax_pfn_mkwrite, 127 }; 128 129 static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma) 130 { 131 if (!IS_DAX(file_inode(file))) 132 return generic_file_mmap(file, vma); 133 134 file_accessed(file); 135 vma->vm_ops = &ext2_dax_vm_ops; 136 vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE; 137 return 0; 138 } 139 #else 140 #define ext2_file_mmap generic_file_mmap 141 #endif 142 143 /* 144 * Called when filp is released. This happens when all file descriptors 145 * for a single struct file are closed. Note that different open() calls 146 * for the same file yield different struct file structures. 147 */ 148 static int ext2_release_file (struct inode * inode, struct file * filp) 149 { 150 if (filp->f_mode & FMODE_WRITE) { 151 mutex_lock(&EXT2_I(inode)->truncate_mutex); 152 ext2_discard_reservation(inode); 153 mutex_unlock(&EXT2_I(inode)->truncate_mutex); 154 } 155 return 0; 156 } 157 158 int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync) 159 { 160 int ret; 161 struct super_block *sb = file->f_mapping->host->i_sb; 162 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 163 164 ret = generic_file_fsync(file, start, end, datasync); 165 if (ret == -EIO || test_and_clear_bit(AS_EIO, &mapping->flags)) { 166 /* We don't really know where the IO error happened... */ 167 ext2_error(sb, __func__, 168 "detected IO error when writing metadata buffers"); 169 ret = -EIO; 170 } 171 return ret; 172 } 173 174 /* 175 * We have mostly NULL's here: the current defaults are ok for 176 * the ext2 filesystem. 177 */ 178 const struct file_operations ext2_file_operations = { 179 .llseek = generic_file_llseek, 180 .read_iter = generic_file_read_iter, 181 .write_iter = generic_file_write_iter, 182 .unlocked_ioctl = ext2_ioctl, 183 #ifdef CONFIG_COMPAT 184 .compat_ioctl = ext2_compat_ioctl, 185 #endif 186 .mmap = ext2_file_mmap, 187 .open = dquot_file_open, 188 .release = ext2_release_file, 189 .fsync = ext2_fsync, 190 .splice_read = generic_file_splice_read, 191 .splice_write = iter_file_splice_write, 192 }; 193 194 const struct inode_operations ext2_file_inode_operations = { 195 #ifdef CONFIG_EXT2_FS_XATTR 196 .setxattr = generic_setxattr, 197 .getxattr = generic_getxattr, 198 .listxattr = ext2_listxattr, 199 .removexattr = generic_removexattr, 200 #endif 201 .setattr = ext2_setattr, 202 .get_acl = ext2_get_acl, 203 .set_acl = ext2_set_acl, 204 .fiemap = ext2_fiemap, 205 }; 206