ext2: set FMODE_CAN_ODIRECT instead of a dummy direct_IO method
[linux-2.6-block.git] / fs / ext2 / file.c
CommitLineData
b2441318 1// SPDX-License-Identifier: GPL-2.0
1da177e4
LT
2/*
3 * linux/fs/ext2/file.c
4 *
5 * Copyright (C) 1992, 1993, 1994, 1995
6 * Remy Card (card@masi.ibp.fr)
7 * Laboratoire MASI - Institut Blaise Pascal
8 * Universite Pierre et Marie Curie (Paris VI)
9 *
10 * from
11 *
12 * linux/fs/minix/file.c
13 *
14 * Copyright (C) 1991, 1992 Linus Torvalds
15 *
16 * ext2 fs regular file handling primitives
17 *
18 * 64-bit file support on 64-bit platforms by Jakub Jelinek
19 * (jj@sunsite.ms.mff.cuni.cz)
20 */
21
22#include <linux/time.h>
48bde86d 23#include <linux/pagemap.h>
c94c2acf 24#include <linux/dax.h>
871a2931 25#include <linux/quotaops.h>
25f4e702
CH
26#include <linux/iomap.h>
27#include <linux/uio.h>
d0530704 28#include <linux/buffer_head.h>
1da177e4
LT
29#include "ext2.h"
30#include "xattr.h"
31#include "acl.h"
6e335cd7 32#include "trace.h"
1da177e4 33
6cd176a5 34#ifdef CONFIG_FS_DAX
25f4e702
CH
35static 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);
11c59c92 44 ret = dax_iomap_rw(iocb, to, &ext2_iomap_ops);
25f4e702
CH
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
11c59c92 68 ret = dax_iomap_rw(iocb, from, &ext2_iomap_ops);
25f4e702
CH
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
5726b27b
RZ
81/*
82 * The lock ordering for ext2 DAX fault paths is:
83 *
c1e8d7c6 84 * mmap_lock (MM)
5726b27b 85 * sb_start_pagefault (vfs, freeze)
70f3bad8 86 * address_space->invalidate_lock
5726b27b
RZ
87 * address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX)
88 * ext2_inode_info->truncate_mutex
89 *
90 * The default page_lock and i_size verification done by non-DAX fault paths
91 * is sufficient because ext2 doesn't support hole punching.
92 */
06856938 93static vm_fault_t ext2_dax_fault(struct vm_fault *vmf)
f7ca90b1 94{
11bac800 95 struct inode *inode = file_inode(vmf->vma->vm_file);
06856938 96 vm_fault_t ret;
1ef6ea0e
MP
97 bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
98 (vmf->vma->vm_flags & VM_SHARED);
5726b27b 99
1ef6ea0e 100 if (write) {
5726b27b 101 sb_start_pagefault(inode->i_sb);
11bac800 102 file_update_time(vmf->vma->vm_file);
5726b27b 103 }
70f3bad8 104 filemap_invalidate_lock_shared(inode->i_mapping);
5726b27b 105
1d024e7a 106 ret = dax_iomap_fault(vmf, 0, NULL, NULL, &ext2_iomap_ops);
5726b27b 107
70f3bad8 108 filemap_invalidate_unlock_shared(inode->i_mapping);
1ef6ea0e 109 if (write)
5726b27b
RZ
110 sb_end_pagefault(inode->i_sb);
111 return ret;
f7ca90b1
MW
112}
113
f7ca90b1
MW
114static const struct vm_operations_struct ext2_dax_vm_ops = {
115 .fault = ext2_dax_fault,
03e0990f 116 /*
a2d58167 117 * .huge_fault is not supported for DAX because allocation in ext2
03e0990f
RZ
118 * cannot be reliably aligned to huge page sizes and so pmd faults
119 * will always fail and fail back to regular faults.
120 */
1e9d180b 121 .page_mkwrite = ext2_dax_fault,
91d25ba8 122 .pfn_mkwrite = ext2_dax_fault,
f7ca90b1
MW
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;
f7ca90b1
MW
132 return 0;
133}
134#else
135#define ext2_file_mmap generic_file_mmap
136#endif
137
1da177e4 138/*
a6739af8
JK
139 * Called when filp is released. This happens when all file descriptors
140 * for a single struct file are closed. Note that different open() calls
141 * for the same file yield different struct file structures.
1da177e4
LT
142 */
143static int ext2_release_file (struct inode * inode, struct file * filp)
144{
a686cd89
MB
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 }
1da177e4
LT
150 return 0;
151}
152
02c24a82 153int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
48bde86d
JK
154{
155 int ret;
7ea80859 156 struct super_block *sb = file->f_mapping->host->i_sb;
48bde86d 157
d0530704 158 ret = generic_buffers_fsync(file, start, end, datasync);
dac257f7 159 if (ret == -EIO)
48bde86d
JK
160 /* We don't really know where the IO error happened... */
161 ext2_error(sb, __func__,
162 "detected IO error when writing metadata buffers");
48bde86d
JK
163 return ret;
164}
165
fb5de435
RHI
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
6e335cd7 172 trace_ext2_dio_read_begin(iocb, to, 0);
fb5de435
RHI
173 inode_lock_shared(inode);
174 ret = iomap_dio_rw(iocb, to, &ext2_iomap_ops, NULL, 0, NULL, 0);
175 inode_unlock_shared(inode);
6e335cd7 176 trace_ext2_dio_read_end(iocb, to, ret);
fb5de435
RHI
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 before
192 * page cache gets invalidated in iomap_dio_rw(). This prevents racing
193 * buffered reads from zeroing out too much from page cache pages.
194 * Note that all extending writes always happens synchronously with
195 * inode lock held by ext2_dio_write_iter(). So it is safe to update
196 * 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:
6e335cd7 204 trace_ext2_dio_write_endio(iocb, size, error);
fb5de435
RHI
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);
6e335cd7 221 ssize_t status = 0;
fb5de435 222
6e335cd7 223 trace_ext2_dio_write_begin(iocb, from, 0);
fb5de435
RHI
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;
fb5de435
RHI
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
fb5de435
RHI
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);
6e335cd7
RHI
275 if (status)
276 trace_ext2_dio_write_buff_end(iocb, from, status);
277 trace_ext2_dio_write_end(iocb, from, ret);
fb5de435
RHI
278 return ret;
279}
280
25f4e702
CH
281static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
282{
283#ifdef CONFIG_FS_DAX
284 if (IS_DAX(iocb->ki_filp->f_mapping->host))
285 return ext2_dax_read_iter(iocb, to);
286#endif
fb5de435
RHI
287 if (iocb->ki_flags & IOCB_DIRECT)
288 return ext2_dio_read_iter(iocb, to);
289
25f4e702
CH
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_DAX
296 if (IS_DAX(iocb->ki_filp->f_mapping->host))
297 return ext2_dax_write_iter(iocb, from);
298#endif
fb5de435
RHI
299 if (iocb->ki_flags & IOCB_DIRECT)
300 return ext2_dio_write_iter(iocb, from);
301
25f4e702
CH
302 return generic_file_write_iter(iocb, from);
303}
304
3e90417f
RHI
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
4b6f5d20 311const struct file_operations ext2_file_operations = {
1da177e4 312 .llseek = generic_file_llseek,
25f4e702
CH
313 .read_iter = ext2_file_read_iter,
314 .write_iter = ext2_file_write_iter,
14f9f7b2 315 .unlocked_ioctl = ext2_ioctl,
e322ff07
DH
316#ifdef CONFIG_COMPAT
317 .compat_ioctl = ext2_compat_ioctl,
318#endif
f7ca90b1 319 .mmap = ext2_file_mmap,
3e90417f 320 .open = ext2_file_open,
1da177e4 321 .release = ext2_release_file,
48bde86d 322 .fsync = ext2_fsync,
dbe6ec81 323 .get_unmapped_area = thp_get_unmapped_area,
2cb1e089 324 .splice_read = filemap_splice_read,
8d020765 325 .splice_write = iter_file_splice_write,
1da177e4
LT
326};
327
754661f1 328const struct inode_operations ext2_file_inode_operations = {
1da177e4 329 .listxattr = ext2_listxattr,
93bc420e 330 .getattr = ext2_getattr,
1da177e4 331 .setattr = ext2_setattr,
cac2f8b8 332 .get_inode_acl = ext2_get_acl,
64e178a7 333 .set_acl = ext2_set_acl,
68c9d702 334 .fiemap = ext2_fiemap,
aba405e3
MS
335 .fileattr_get = ext2_fileattr_get,
336 .fileattr_set = ext2_fileattr_set,
1da177e4 337};