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1// SPDX-License-Identifier: GPL-2.02/*3 * linux/fs/ext2/file.c4 *5 * Copyright (C) 1992, 1993, 1994, 19956 * Remy Card (card@masi.ibp.fr)7 * Laboratoire MASI - Institut Blaise Pascal8 * Universite Pierre et Marie Curie (Paris VI)9 *10 * from11 *12 * linux/fs/minix/file.c13 *14 * Copyright (C) 1991, 1992 Linus Torvalds15 *16 * ext2 fs regular file handling primitives17 *18 * 64-bit file support on 64-bit platforms by Jakub Jelinek19 * (jj@sunsite.ms.mff.cuni.cz)20 */21 22#include <linux/time.h>23#include <linux/pagemap.h>24#include <linux/dax.h>25#include <linux/quotaops.h>26#include <linux/iomap.h>27#include <linux/uio.h>28#include <linux/buffer_head.h>29#include "ext2.h"30#include "xattr.h"31#include "acl.h"32#include "trace.h"33 34#ifdef CONFIG_FS_DAX35static ssize_t ext2_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)36{37 struct inode *inode = iocb->ki_filp->f_mapping->host;38 ssize_t ret;39 40 if (!iov_iter_count(to))41 return 0; /* skip atime */42 43 inode_lock_shared(inode);44 ret = dax_iomap_rw(iocb, to, &ext2_iomap_ops);45 inode_unlock_shared(inode);46 47 file_accessed(iocb->ki_filp);48 return ret;49}50 51static ssize_t ext2_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)52{53 struct file *file = iocb->ki_filp;54 struct inode *inode = file->f_mapping->host;55 ssize_t ret;56 57 inode_lock(inode);58 ret = generic_write_checks(iocb, from);59 if (ret <= 0)60 goto out_unlock;61 ret = file_remove_privs(file);62 if (ret)63 goto out_unlock;64 ret = file_update_time(file);65 if (ret)66 goto out_unlock;67 68 ret = dax_iomap_rw(iocb, from, &ext2_iomap_ops);69 if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {70 i_size_write(inode, iocb->ki_pos);71 mark_inode_dirty(inode);72 }73 74out_unlock:75 inode_unlock(inode);76 if (ret > 0)77 ret = generic_write_sync(iocb, ret);78 return ret;79}80 81/*82 * The lock ordering for ext2 DAX fault paths is:83 *84 * mmap_lock (MM)85 * sb_start_pagefault (vfs, freeze)86 * address_space->invalidate_lock87 * address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX)88 * ext2_inode_info->truncate_mutex89 *90 * The default page_lock and i_size verification done by non-DAX fault paths91 * is sufficient because ext2 doesn't support hole punching.92 */93static vm_fault_t ext2_dax_fault(struct vm_fault *vmf)94{95 struct inode *inode = file_inode(vmf->vma->vm_file);96 vm_fault_t ret;97 bool write = (vmf->flags & FAULT_FLAG_WRITE) &&98 (vmf->vma->vm_flags & VM_SHARED);99 100 if (write) {101 sb_start_pagefault(inode->i_sb);102 file_update_time(vmf->vma->vm_file);103 }104 filemap_invalidate_lock_shared(inode->i_mapping);105 106 ret = dax_iomap_fault(vmf, 0, NULL, NULL, &ext2_iomap_ops);107 108 filemap_invalidate_unlock_shared(inode->i_mapping);109 if (write)110 sb_end_pagefault(inode->i_sb);111 return ret;112}113 114static const struct vm_operations_struct ext2_dax_vm_ops = {115 .fault = ext2_dax_fault,116 /*117 * .huge_fault is not supported for DAX because allocation in ext2118 * cannot be reliably aligned to huge page sizes and so pmd faults119 * will always fail and fail back to regular faults.120 */121 .page_mkwrite = ext2_dax_fault,122 .pfn_mkwrite = ext2_dax_fault,123};124 125static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)126{127 if (!IS_DAX(file_inode(file)))128 return generic_file_mmap(file, vma);129 130 file_accessed(file);131 vma->vm_ops = &ext2_dax_vm_ops;132 return 0;133}134#else135#define ext2_file_mmap generic_file_mmap136#endif137 138/*139 * Called when filp is released. This happens when all file descriptors140 * for a single struct file are closed. Note that different open() calls141 * for the same file yield different struct file structures.142 */143static int ext2_release_file (struct inode * inode, struct file * filp)144{145 if (filp->f_mode & FMODE_WRITE) {146 mutex_lock(&EXT2_I(inode)->truncate_mutex);147 ext2_discard_reservation(inode);148 mutex_unlock(&EXT2_I(inode)->truncate_mutex);149 }150 return 0;151}152 153int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync)154{155 int ret;156 struct super_block *sb = file->f_mapping->host->i_sb;157 158 ret = generic_buffers_fsync(file, start, end, datasync);159 if (ret == -EIO)160 /* We don't really know where the IO error happened... */161 ext2_error(sb, __func__,162 "detected IO error when writing metadata buffers");163 return ret;164}165 166static ssize_t ext2_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)167{168 struct file *file = iocb->ki_filp;169 struct inode *inode = file->f_mapping->host;170 ssize_t ret;171 172 trace_ext2_dio_read_begin(iocb, to, 0);173 inode_lock_shared(inode);174 ret = iomap_dio_rw(iocb, to, &ext2_iomap_ops, NULL, 0, NULL, 0);175 inode_unlock_shared(inode);176 trace_ext2_dio_read_end(iocb, to, ret);177 178 return ret;179}180 181static int ext2_dio_write_end_io(struct kiocb *iocb, ssize_t size,182 int error, unsigned int flags)183{184 loff_t pos = iocb->ki_pos;185 struct inode *inode = file_inode(iocb->ki_filp);186 187 if (error)188 goto out;189 190 /*191 * If we are extending the file, we have to update i_size here before192 * page cache gets invalidated in iomap_dio_rw(). This prevents racing193 * buffered reads from zeroing out too much from page cache pages.194 * Note that all extending writes always happens synchronously with195 * inode lock held by ext2_dio_write_iter(). So it is safe to update196 * inode size here for extending file writes.197 */198 pos += size;199 if (pos > i_size_read(inode)) {200 i_size_write(inode, pos);201 mark_inode_dirty(inode);202 }203out:204 trace_ext2_dio_write_endio(iocb, size, error);205 return error;206}207 208static const struct iomap_dio_ops ext2_dio_write_ops = {209 .end_io = ext2_dio_write_end_io,210};211 212static ssize_t ext2_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)213{214 struct file *file = iocb->ki_filp;215 struct inode *inode = file->f_mapping->host;216 ssize_t ret;217 unsigned int flags = 0;218 unsigned long blocksize = inode->i_sb->s_blocksize;219 loff_t offset = iocb->ki_pos;220 loff_t count = iov_iter_count(from);221 ssize_t status = 0;222 223 trace_ext2_dio_write_begin(iocb, from, 0);224 inode_lock(inode);225 ret = generic_write_checks(iocb, from);226 if (ret <= 0)227 goto out_unlock;228 229 ret = kiocb_modified(iocb);230 if (ret)231 goto out_unlock;232 233 /* use IOMAP_DIO_FORCE_WAIT for unaligned or extending writes */234 if (iocb->ki_pos + iov_iter_count(from) > i_size_read(inode) ||235 (!IS_ALIGNED(iocb->ki_pos | iov_iter_alignment(from), blocksize)))236 flags |= IOMAP_DIO_FORCE_WAIT;237 238 ret = iomap_dio_rw(iocb, from, &ext2_iomap_ops, &ext2_dio_write_ops,239 flags, NULL, 0);240 241 /* ENOTBLK is magic return value for fallback to buffered-io */242 if (ret == -ENOTBLK)243 ret = 0;244 245 if (ret < 0 && ret != -EIOCBQUEUED)246 ext2_write_failed(inode->i_mapping, offset + count);247 248 /* handle case for partial write and for fallback to buffered write */249 if (ret >= 0 && iov_iter_count(from)) {250 loff_t pos, endbyte;251 int ret2;252 253 iocb->ki_flags &= ~IOCB_DIRECT;254 pos = iocb->ki_pos;255 status = generic_perform_write(iocb, from);256 if (unlikely(status < 0)) {257 ret = status;258 goto out_unlock;259 }260 261 ret += status;262 endbyte = pos + status - 1;263 ret2 = filemap_write_and_wait_range(inode->i_mapping, pos,264 endbyte);265 if (!ret2)266 invalidate_mapping_pages(inode->i_mapping,267 pos >> PAGE_SHIFT,268 endbyte >> PAGE_SHIFT);269 if (ret > 0)270 generic_write_sync(iocb, ret);271 }272 273out_unlock:274 inode_unlock(inode);275 if (status)276 trace_ext2_dio_write_buff_end(iocb, from, status);277 trace_ext2_dio_write_end(iocb, from, ret);278 return ret;279}280 281static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)282{283#ifdef CONFIG_FS_DAX284 if (IS_DAX(iocb->ki_filp->f_mapping->host))285 return ext2_dax_read_iter(iocb, to);286#endif287 if (iocb->ki_flags & IOCB_DIRECT)288 return ext2_dio_read_iter(iocb, to);289 290 return generic_file_read_iter(iocb, to);291}292 293static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)294{295#ifdef CONFIG_FS_DAX296 if (IS_DAX(iocb->ki_filp->f_mapping->host))297 return ext2_dax_write_iter(iocb, from);298#endif299 if (iocb->ki_flags & IOCB_DIRECT)300 return ext2_dio_write_iter(iocb, from);301 302 return generic_file_write_iter(iocb, from);303}304 305static int ext2_file_open(struct inode *inode, struct file *filp)306{307 filp->f_mode |= FMODE_CAN_ODIRECT;308 return dquot_file_open(inode, filp);309}310 311const struct file_operations ext2_file_operations = {312 .llseek = generic_file_llseek,313 .read_iter = ext2_file_read_iter,314 .write_iter = ext2_file_write_iter,315 .unlocked_ioctl = ext2_ioctl,316#ifdef CONFIG_COMPAT317 .compat_ioctl = ext2_compat_ioctl,318#endif319 .mmap = ext2_file_mmap,320 .open = ext2_file_open,321 .release = ext2_release_file,322 .fsync = ext2_fsync,323 .get_unmapped_area = thp_get_unmapped_area,324 .splice_read = filemap_splice_read,325 .splice_write = iter_file_splice_write,326};327 328const struct inode_operations ext2_file_inode_operations = {329 .listxattr = ext2_listxattr,330 .getattr = ext2_getattr,331 .setattr = ext2_setattr,332 .get_inode_acl = ext2_get_acl,333 .set_acl = ext2_set_acl,334 .fiemap = ext2_fiemap,335 .fileattr_get = ext2_fileattr_get,336 .fileattr_set = ext2_fileattr_set,337};338