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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 "ext2.h"
29#include "xattr.h"
30#include "acl.h"
31
32#ifdef CONFIG_FS_DAX
33static ssize_t ext2_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
34{
35 struct inode *inode = iocb->ki_filp->f_mapping->host;
36 ssize_t ret;
37
38 if (!iov_iter_count(to))
39 return 0; /* skip atime */
40
41 inode_lock_shared(inode);
42 ret = dax_iomap_rw(iocb, to, &ext2_iomap_ops);
43 inode_unlock_shared(inode);
44
45 file_accessed(iocb->ki_filp);
46 return ret;
47}
48
49static ssize_t ext2_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
50{
51 struct file *file = iocb->ki_filp;
52 struct inode *inode = file->f_mapping->host;
53 ssize_t ret;
54
55 inode_lock(inode);
56 ret = generic_write_checks(iocb, from);
57 if (ret <= 0)
58 goto out_unlock;
59 ret = file_remove_privs(file);
60 if (ret)
61 goto out_unlock;
62 ret = file_update_time(file);
63 if (ret)
64 goto out_unlock;
65
66 ret = dax_iomap_rw(iocb, from, &ext2_iomap_ops);
67 if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
68 i_size_write(inode, iocb->ki_pos);
69 mark_inode_dirty(inode);
70 }
71
72out_unlock:
73 inode_unlock(inode);
74 if (ret > 0)
75 ret = generic_write_sync(iocb, ret);
76 return ret;
77}
78
79/*
80 * The lock ordering for ext2 DAX fault paths is:
81 *
82 * mmap_lock (MM)
83 * sb_start_pagefault (vfs, freeze)
84 * address_space->invalidate_lock
85 * address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX)
86 * ext2_inode_info->truncate_mutex
87 *
88 * The default page_lock and i_size verification done by non-DAX fault paths
89 * is sufficient because ext2 doesn't support hole punching.
90 */
91static vm_fault_t ext2_dax_fault(struct vm_fault *vmf)
92{
93 struct inode *inode = file_inode(vmf->vma->vm_file);
94 vm_fault_t ret;
95 bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
96 (vmf->vma->vm_flags & VM_SHARED);
97
98 if (write) {
99 sb_start_pagefault(inode->i_sb);
100 file_update_time(vmf->vma->vm_file);
101 }
102 filemap_invalidate_lock_shared(inode->i_mapping);
103
104 ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, NULL, &ext2_iomap_ops);
105
106 filemap_invalidate_unlock_shared(inode->i_mapping);
107 if (write)
108 sb_end_pagefault(inode->i_sb);
109 return ret;
110}
111
112static const struct vm_operations_struct ext2_dax_vm_ops = {
113 .fault = ext2_dax_fault,
114 /*
115 * .huge_fault is not supported for DAX because allocation in ext2
116 * cannot be reliably aligned to huge page sizes and so pmd faults
117 * will always fail and fail back to regular faults.
118 */
119 .page_mkwrite = ext2_dax_fault,
120 .pfn_mkwrite = ext2_dax_fault,
121};
122
123static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)
124{
125 if (!IS_DAX(file_inode(file)))
126 return generic_file_mmap(file, vma);
127
128 file_accessed(file);
129 vma->vm_ops = &ext2_dax_vm_ops;
130 return 0;
131}
132#else
133#define ext2_file_mmap generic_file_mmap
134#endif
135
136/*
137 * Called when filp is released. This happens when all file descriptors
138 * for a single struct file are closed. Note that different open() calls
139 * for the same file yield different struct file structures.
140 */
141static int ext2_release_file (struct inode * inode, struct file * filp)
142{
143 if (filp->f_mode & FMODE_WRITE) {
144 mutex_lock(&EXT2_I(inode)->truncate_mutex);
145 ext2_discard_reservation(inode);
146 mutex_unlock(&EXT2_I(inode)->truncate_mutex);
147 }
148 return 0;
149}
150
151int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
152{
153 int ret;
154 struct super_block *sb = file->f_mapping->host->i_sb;
155
156 ret = generic_file_fsync(file, start, end, datasync);
157 if (ret == -EIO)
158 /* We don't really know where the IO error happened... */
159 ext2_error(sb, __func__,
160 "detected IO error when writing metadata buffers");
161 return ret;
162}
163
164static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
165{
166#ifdef CONFIG_FS_DAX
167 if (IS_DAX(iocb->ki_filp->f_mapping->host))
168 return ext2_dax_read_iter(iocb, to);
169#endif
170 return generic_file_read_iter(iocb, to);
171}
172
173static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
174{
175#ifdef CONFIG_FS_DAX
176 if (IS_DAX(iocb->ki_filp->f_mapping->host))
177 return ext2_dax_write_iter(iocb, from);
178#endif
179 return generic_file_write_iter(iocb, from);
180}
181
182const struct file_operations ext2_file_operations = {
183 .llseek = generic_file_llseek,
184 .read_iter = ext2_file_read_iter,
185 .write_iter = ext2_file_write_iter,
186 .unlocked_ioctl = ext2_ioctl,
187#ifdef CONFIG_COMPAT
188 .compat_ioctl = ext2_compat_ioctl,
189#endif
190 .mmap = ext2_file_mmap,
191 .open = dquot_file_open,
192 .release = ext2_release_file,
193 .fsync = ext2_fsync,
194 .get_unmapped_area = thp_get_unmapped_area,
195 .splice_read = generic_file_splice_read,
196 .splice_write = iter_file_splice_write,
197};
198
199const struct inode_operations ext2_file_inode_operations = {
200 .listxattr = ext2_listxattr,
201 .getattr = ext2_getattr,
202 .setattr = ext2_setattr,
203 .get_inode_acl = ext2_get_acl,
204 .set_acl = ext2_set_acl,
205 .fiemap = ext2_fiemap,
206 .fileattr_get = ext2_fileattr_get,
207 .fileattr_set = ext2_fileattr_set,
208};
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 <linux/iomap.h>
26#include <linux/uio.h>
27#include "ext2.h"
28#include "xattr.h"
29#include "acl.h"
30
31#ifdef CONFIG_FS_DAX
32static ssize_t ext2_dax_read_iter(struct kiocb *iocb, struct iov_iter *to)
33{
34 struct inode *inode = iocb->ki_filp->f_mapping->host;
35 ssize_t ret;
36
37 if (!iov_iter_count(to))
38 return 0; /* skip atime */
39
40 inode_lock_shared(inode);
41 ret = dax_iomap_rw(iocb, to, &ext2_iomap_ops);
42 inode_unlock_shared(inode);
43
44 file_accessed(iocb->ki_filp);
45 return ret;
46}
47
48static ssize_t ext2_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
49{
50 struct file *file = iocb->ki_filp;
51 struct inode *inode = file->f_mapping->host;
52 ssize_t ret;
53
54 inode_lock(inode);
55 ret = generic_write_checks(iocb, from);
56 if (ret <= 0)
57 goto out_unlock;
58 ret = file_remove_privs(file);
59 if (ret)
60 goto out_unlock;
61 ret = file_update_time(file);
62 if (ret)
63 goto out_unlock;
64
65 ret = dax_iomap_rw(iocb, from, &ext2_iomap_ops);
66 if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
67 i_size_write(inode, iocb->ki_pos);
68 mark_inode_dirty(inode);
69 }
70
71out_unlock:
72 inode_unlock(inode);
73 if (ret > 0)
74 ret = generic_write_sync(iocb, ret);
75 return ret;
76}
77
78/*
79 * The lock ordering for ext2 DAX fault paths is:
80 *
81 * mmap_sem (MM)
82 * sb_start_pagefault (vfs, freeze)
83 * ext2_inode_info->dax_sem
84 * address_space->i_mmap_rwsem or page_lock (mutually exclusive in DAX)
85 * ext2_inode_info->truncate_mutex
86 *
87 * The default page_lock and i_size verification done by non-DAX fault paths
88 * is sufficient because ext2 doesn't support hole punching.
89 */
90static int ext2_dax_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
91{
92 struct inode *inode = file_inode(vma->vm_file);
93 struct ext2_inode_info *ei = EXT2_I(inode);
94 int ret;
95
96 if (vmf->flags & FAULT_FLAG_WRITE) {
97 sb_start_pagefault(inode->i_sb);
98 file_update_time(vma->vm_file);
99 }
100 down_read(&ei->dax_sem);
101
102 ret = dax_iomap_fault(vma, vmf, &ext2_iomap_ops);
103
104 up_read(&ei->dax_sem);
105 if (vmf->flags & FAULT_FLAG_WRITE)
106 sb_end_pagefault(inode->i_sb);
107 return ret;
108}
109
110static int ext2_dax_pfn_mkwrite(struct vm_area_struct *vma,
111 struct vm_fault *vmf)
112{
113 struct inode *inode = file_inode(vma->vm_file);
114 struct ext2_inode_info *ei = EXT2_I(inode);
115 loff_t size;
116 int ret;
117
118 sb_start_pagefault(inode->i_sb);
119 file_update_time(vma->vm_file);
120 down_read(&ei->dax_sem);
121
122 /* check that the faulting page hasn't raced with truncate */
123 size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
124 if (vmf->pgoff >= size)
125 ret = VM_FAULT_SIGBUS;
126 else
127 ret = dax_pfn_mkwrite(vma, vmf);
128
129 up_read(&ei->dax_sem);
130 sb_end_pagefault(inode->i_sb);
131 return ret;
132}
133
134static const struct vm_operations_struct ext2_dax_vm_ops = {
135 .fault = ext2_dax_fault,
136 /*
137 * .pmd_fault is not supported for DAX because allocation in ext2
138 * cannot be reliably aligned to huge page sizes and so pmd faults
139 * will always fail and fail back to regular faults.
140 */
141 .page_mkwrite = ext2_dax_fault,
142 .pfn_mkwrite = ext2_dax_pfn_mkwrite,
143};
144
145static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)
146{
147 if (!IS_DAX(file_inode(file)))
148 return generic_file_mmap(file, vma);
149
150 file_accessed(file);
151 vma->vm_ops = &ext2_dax_vm_ops;
152 vma->vm_flags |= VM_MIXEDMAP;
153 return 0;
154}
155#else
156#define ext2_file_mmap generic_file_mmap
157#endif
158
159/*
160 * Called when filp is released. This happens when all file descriptors
161 * for a single struct file are closed. Note that different open() calls
162 * for the same file yield different struct file structures.
163 */
164static int ext2_release_file (struct inode * inode, struct file * filp)
165{
166 if (filp->f_mode & FMODE_WRITE) {
167 mutex_lock(&EXT2_I(inode)->truncate_mutex);
168 ext2_discard_reservation(inode);
169 mutex_unlock(&EXT2_I(inode)->truncate_mutex);
170 }
171 return 0;
172}
173
174int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
175{
176 int ret;
177 struct super_block *sb = file->f_mapping->host->i_sb;
178 struct address_space *mapping = sb->s_bdev->bd_inode->i_mapping;
179
180 ret = generic_file_fsync(file, start, end, datasync);
181 if (ret == -EIO || test_and_clear_bit(AS_EIO, &mapping->flags)) {
182 /* We don't really know where the IO error happened... */
183 ext2_error(sb, __func__,
184 "detected IO error when writing metadata buffers");
185 ret = -EIO;
186 }
187 return ret;
188}
189
190static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
191{
192#ifdef CONFIG_FS_DAX
193 if (IS_DAX(iocb->ki_filp->f_mapping->host))
194 return ext2_dax_read_iter(iocb, to);
195#endif
196 return generic_file_read_iter(iocb, to);
197}
198
199static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
200{
201#ifdef CONFIG_FS_DAX
202 if (IS_DAX(iocb->ki_filp->f_mapping->host))
203 return ext2_dax_write_iter(iocb, from);
204#endif
205 return generic_file_write_iter(iocb, from);
206}
207
208const struct file_operations ext2_file_operations = {
209 .llseek = generic_file_llseek,
210 .read_iter = ext2_file_read_iter,
211 .write_iter = ext2_file_write_iter,
212 .unlocked_ioctl = ext2_ioctl,
213#ifdef CONFIG_COMPAT
214 .compat_ioctl = ext2_compat_ioctl,
215#endif
216 .mmap = ext2_file_mmap,
217 .open = dquot_file_open,
218 .release = ext2_release_file,
219 .fsync = ext2_fsync,
220 .get_unmapped_area = thp_get_unmapped_area,
221 .splice_read = generic_file_splice_read,
222 .splice_write = iter_file_splice_write,
223};
224
225const struct inode_operations ext2_file_inode_operations = {
226#ifdef CONFIG_EXT2_FS_XATTR
227 .listxattr = ext2_listxattr,
228#endif
229 .setattr = ext2_setattr,
230 .get_acl = ext2_get_acl,
231 .set_acl = ext2_set_acl,
232 .fiemap = ext2_fiemap,
233};