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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 | // SPDX-License-Identifier: GPL-2.0 /* * linux/fs/ext2/file.c * * Copyright (C) 1992, 1993, 1994, 1995 * Remy Card (card@masi.ibp.fr) * Laboratoire MASI - Institut Blaise Pascal * Universite Pierre et Marie Curie (Paris VI) * * from * * linux/fs/minix/file.c * * Copyright (C) 1991, 1992 Linus Torvalds * * ext2 fs regular file handling primitives * * 64-bit file support on 64-bit platforms by Jakub Jelinek * (jj@sunsite.ms.mff.cuni.cz) */ #include <linux/time.h> #include <linux/pagemap.h> #include <linux/dax.h> #include <linux/quotaops.h> #include <linux/iomap.h> #include <linux/uio.h> #include "ext2.h" #include "xattr.h" #include "acl.h" #ifdef CONFIG_FS_DAX static ssize_t ext2_dax_read_iter(struct kiocb *iocb, struct iov_iter *to) { struct inode *inode = iocb->ki_filp->f_mapping->host; ssize_t ret; if (!iov_iter_count(to)) return 0; /* skip atime */ inode_lock_shared(inode); ret = dax_iomap_rw(iocb, to, &ext2_iomap_ops); inode_unlock_shared(inode); file_accessed(iocb->ki_filp); return ret; } static ssize_t ext2_dax_write_iter(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp; struct inode *inode = file->f_mapping->host; ssize_t ret; inode_lock(inode); ret = generic_write_checks(iocb, from); if (ret <= 0) goto out_unlock; ret = file_remove_privs(file); if (ret) goto out_unlock; ret = file_update_time(file); if (ret) goto out_unlock; ret = dax_iomap_rw(iocb, from, &ext2_iomap_ops); if (ret > 0 && iocb->ki_pos > i_size_read(inode)) { i_size_write(inode, iocb->ki_pos); mark_inode_dirty(inode); } out_unlock: inode_unlock(inode); if (ret > 0) ret = generic_write_sync(iocb, ret); return ret; } /* * The lock ordering for ext2 DAX fault paths is: * * mmap_lock (MM) * sb_start_pagefault (vfs, freeze) * address_space->invalidate_lock * address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX) * ext2_inode_info->truncate_mutex * * The default page_lock and i_size verification done by non-DAX fault paths * is sufficient because ext2 doesn't support hole punching. */ static vm_fault_t ext2_dax_fault(struct vm_fault *vmf) { struct inode *inode = file_inode(vmf->vma->vm_file); vm_fault_t ret; bool write = (vmf->flags & FAULT_FLAG_WRITE) && (vmf->vma->vm_flags & VM_SHARED); if (write) { sb_start_pagefault(inode->i_sb); file_update_time(vmf->vma->vm_file); } filemap_invalidate_lock_shared(inode->i_mapping); ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, NULL, &ext2_iomap_ops); filemap_invalidate_unlock_shared(inode->i_mapping); if (write) sb_end_pagefault(inode->i_sb); return ret; } static const struct vm_operations_struct ext2_dax_vm_ops = { .fault = ext2_dax_fault, /* * .huge_fault is not supported for DAX because allocation in ext2 * cannot be reliably aligned to huge page sizes and so pmd faults * will always fail and fail back to regular faults. */ .page_mkwrite = ext2_dax_fault, .pfn_mkwrite = ext2_dax_fault, }; static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma) { if (!IS_DAX(file_inode(file))) return generic_file_mmap(file, vma); file_accessed(file); vma->vm_ops = &ext2_dax_vm_ops; return 0; } #else #define ext2_file_mmap generic_file_mmap #endif /* * Called when filp is released. This happens when all file descriptors * for a single struct file are closed. Note that different open() calls * for the same file yield different struct file structures. */ static int ext2_release_file (struct inode * inode, struct file * filp) { if (filp->f_mode & FMODE_WRITE) { mutex_lock(&EXT2_I(inode)->truncate_mutex); ext2_discard_reservation(inode); mutex_unlock(&EXT2_I(inode)->truncate_mutex); } return 0; } int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync) { int ret; struct super_block *sb = file->f_mapping->host->i_sb; ret = generic_file_fsync(file, start, end, datasync); if (ret == -EIO) /* We don't really know where the IO error happened... */ ext2_error(sb, __func__, "detected IO error when writing metadata buffers"); return ret; } static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to) { #ifdef CONFIG_FS_DAX if (IS_DAX(iocb->ki_filp->f_mapping->host)) return ext2_dax_read_iter(iocb, to); #endif return generic_file_read_iter(iocb, to); } static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from) { #ifdef CONFIG_FS_DAX if (IS_DAX(iocb->ki_filp->f_mapping->host)) return ext2_dax_write_iter(iocb, from); #endif return generic_file_write_iter(iocb, from); } const struct file_operations ext2_file_operations = { .llseek = generic_file_llseek, .read_iter = ext2_file_read_iter, .write_iter = ext2_file_write_iter, .unlocked_ioctl = ext2_ioctl, #ifdef CONFIG_COMPAT .compat_ioctl = ext2_compat_ioctl, #endif .mmap = ext2_file_mmap, .open = dquot_file_open, .release = ext2_release_file, .fsync = ext2_fsync, .get_unmapped_area = thp_get_unmapped_area, .splice_read = generic_file_splice_read, .splice_write = iter_file_splice_write, }; const struct inode_operations ext2_file_inode_operations = { .listxattr = ext2_listxattr, .getattr = ext2_getattr, .setattr = ext2_setattr, .get_acl = ext2_get_acl, .set_acl = ext2_set_acl, .fiemap = ext2_fiemap, .fileattr_get = ext2_fileattr_get, .fileattr_set = ext2_fileattr_set, }; |