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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 */
42static 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
62static 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
83static 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
107static 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
114static 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 */
133static 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
143int 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 */
163const 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
179const 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};
1// SPDX-License-Identifier: GPL-2.0
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>
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_DAX
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);
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_lock
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 */
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 ext2
118 * cannot be reliably aligned to huge page sizes and so pmd faults
119 * 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#else
135#define ext2_file_mmap generic_file_mmap
136#endif
137
138/*
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.
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 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:
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_DAX
284 if (IS_DAX(iocb->ki_filp->f_mapping->host))
285 return ext2_dax_read_iter(iocb, to);
286#endif
287 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_DAX
296 if (IS_DAX(iocb->ki_filp->f_mapping->host))
297 return ext2_dax_write_iter(iocb, from);
298#endif
299 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_COMPAT
317 .compat_ioctl = ext2_compat_ioctl,
318#endif
319 .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};