| 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 | loff_t size; |
| 106 | int ret; |
| 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 | else |
| 117 | ret = dax_pfn_mkwrite(vma, vmf); |
| 118 | |
| 119 | up_read(&ei->dax_sem); |
| 120 | sb_end_pagefault(inode->i_sb); |
| 121 | return ret; |
| 122 | } |
| 123 | |
| 124 | static const struct vm_operations_struct ext2_dax_vm_ops = { |
| 125 | .fault = ext2_dax_fault, |
| 126 | .pmd_fault = ext2_dax_pmd_fault, |
| 127 | .page_mkwrite = ext2_dax_mkwrite, |
| 128 | .pfn_mkwrite = ext2_dax_pfn_mkwrite, |
| 129 | }; |
| 130 | |
| 131 | static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma) |
| 132 | { |
| 133 | if (!IS_DAX(file_inode(file))) |
| 134 | return generic_file_mmap(file, vma); |
| 135 | |
| 136 | file_accessed(file); |
| 137 | vma->vm_ops = &ext2_dax_vm_ops; |
| 138 | vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE; |
| 139 | return 0; |
| 140 | } |
| 141 | #else |
| 142 | #define ext2_file_mmap generic_file_mmap |
| 143 | #endif |
| 144 | |
| 145 | /* |
| 146 | * Called when filp is released. This happens when all file descriptors |
| 147 | * for a single struct file are closed. Note that different open() calls |
| 148 | * for the same file yield different struct file structures. |
| 149 | */ |
| 150 | static int ext2_release_file (struct inode * inode, struct file * filp) |
| 151 | { |
| 152 | if (filp->f_mode & FMODE_WRITE) { |
| 153 | mutex_lock(&EXT2_I(inode)->truncate_mutex); |
| 154 | ext2_discard_reservation(inode); |
| 155 | mutex_unlock(&EXT2_I(inode)->truncate_mutex); |
| 156 | } |
| 157 | return 0; |
| 158 | } |
| 159 | |
| 160 | int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync) |
| 161 | { |
| 162 | int ret; |
| 163 | struct super_block *sb = file->f_mapping->host->i_sb; |
| 164 | struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping; |
| 165 | |
| 166 | ret = generic_file_fsync(file, start, end, datasync); |
| 167 | if (ret == -EIO || test_and_clear_bit(AS_EIO, &mapping->flags)) { |
| 168 | /* We don't really know where the IO error happened... */ |
| 169 | ext2_error(sb, __func__, |
| 170 | "detected IO error when writing metadata buffers"); |
| 171 | ret = -EIO; |
| 172 | } |
| 173 | return ret; |
| 174 | } |
| 175 | |
| 176 | /* |
| 177 | * We have mostly NULL's here: the current defaults are ok for |
| 178 | * the ext2 filesystem. |
| 179 | */ |
| 180 | const struct file_operations ext2_file_operations = { |
| 181 | .llseek = generic_file_llseek, |
| 182 | .read_iter = generic_file_read_iter, |
| 183 | .write_iter = generic_file_write_iter, |
| 184 | .unlocked_ioctl = ext2_ioctl, |
| 185 | #ifdef CONFIG_COMPAT |
| 186 | .compat_ioctl = ext2_compat_ioctl, |
| 187 | #endif |
| 188 | .mmap = ext2_file_mmap, |
| 189 | .open = dquot_file_open, |
| 190 | .release = ext2_release_file, |
| 191 | .fsync = ext2_fsync, |
| 192 | .splice_read = generic_file_splice_read, |
| 193 | .splice_write = iter_file_splice_write, |
| 194 | }; |
| 195 | |
| 196 | const struct inode_operations ext2_file_inode_operations = { |
| 197 | #ifdef CONFIG_EXT2_FS_XATTR |
| 198 | .setxattr = generic_setxattr, |
| 199 | .getxattr = generic_getxattr, |
| 200 | .listxattr = ext2_listxattr, |
| 201 | .removexattr = generic_removexattr, |
| 202 | #endif |
| 203 | .setattr = ext2_setattr, |
| 204 | .get_acl = ext2_get_acl, |
| 205 | .set_acl = ext2_set_acl, |
| 206 | .fiemap = ext2_fiemap, |
| 207 | }; |