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); 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); 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_pfn_mkwrite(struct vm_area_struct *vma, 84 struct vm_fault *vmf) 85 { 86 struct inode *inode = file_inode(vma->vm_file); 87 struct ext2_inode_info *ei = EXT2_I(inode); 88 loff_t size; 89 int ret; 90 91 sb_start_pagefault(inode->i_sb); 92 file_update_time(vma->vm_file); 93 down_read(&ei->dax_sem); 94 95 /* check that the faulting page hasn't raced with truncate */ 96 size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT; 97 if (vmf->pgoff >= size) 98 ret = VM_FAULT_SIGBUS; 99 else 100 ret = dax_pfn_mkwrite(vma, vmf); 101 102 up_read(&ei->dax_sem); 103 sb_end_pagefault(inode->i_sb); 104 return ret; 105 } 106 107 static const struct vm_operations_struct ext2_dax_vm_ops = { 108 .fault = ext2_dax_fault, 109 .pmd_fault = ext2_dax_pmd_fault, 110 .page_mkwrite = ext2_dax_fault, 111 .pfn_mkwrite = ext2_dax_pfn_mkwrite, 112 }; 113 114 static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma) 115 { 116 if (!IS_DAX(file_inode(file))) 117 return generic_file_mmap(file, vma); 118 119 file_accessed(file); 120 vma->vm_ops = &ext2_dax_vm_ops; 121 vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE; 122 return 0; 123 } 124 #else 125 #define ext2_file_mmap generic_file_mmap 126 #endif 127 128 /* 129 * Called when filp is released. This happens when all file descriptors 130 * for a single struct file are closed. Note that different open() calls 131 * for the same file yield different struct file structures. 132 */ 133 static int ext2_release_file (struct inode * inode, struct file * filp) 134 { 135 if (filp->f_mode & FMODE_WRITE) { 136 mutex_lock(&EXT2_I(inode)->truncate_mutex); 137 ext2_discard_reservation(inode); 138 mutex_unlock(&EXT2_I(inode)->truncate_mutex); 139 } 140 return 0; 141 } 142 143 int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync) 144 { 145 int ret; 146 struct super_block *sb = file->f_mapping->host->i_sb; 147 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; 148 149 ret = generic_file_fsync(file, start, end, datasync); 150 if (ret == -EIO || test_and_clear_bit(AS_EIO, &mapping->flags)) { 151 /* We don't really know where the IO error happened... */ 152 ext2_error(sb, __func__, 153 "detected IO error when writing metadata buffers"); 154 ret = -EIO; 155 } 156 return ret; 157 } 158 159 /* 160 * We have mostly NULL's here: the current defaults are ok for 161 * the ext2 filesystem. 162 */ 163 const struct file_operations ext2_file_operations = { 164 .llseek = generic_file_llseek, 165 .read_iter = generic_file_read_iter, 166 .write_iter = generic_file_write_iter, 167 .unlocked_ioctl = ext2_ioctl, 168 #ifdef CONFIG_COMPAT 169 .compat_ioctl = ext2_compat_ioctl, 170 #endif 171 .mmap = ext2_file_mmap, 172 .open = dquot_file_open, 173 .release = ext2_release_file, 174 .fsync = ext2_fsync, 175 .splice_read = generic_file_splice_read, 176 .splice_write = iter_file_splice_write, 177 }; 178 179 const struct inode_operations ext2_file_inode_operations = { 180 #ifdef CONFIG_EXT2_FS_XATTR 181 .setxattr = generic_setxattr, 182 .getxattr = generic_getxattr, 183 .listxattr = ext2_listxattr, 184 .removexattr = generic_removexattr, 185 #endif 186 .setattr = ext2_setattr, 187 .get_acl = ext2_get_acl, 188 .set_acl = ext2_set_acl, 189 .fiemap = ext2_fiemap, 190 }; 191