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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 "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 * ext2_inode_info->dax_sem
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 struct ext2_inode_info *ei = EXT2_I(inode);
95 vm_fault_t ret;
96 bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
97 (vmf->vma->vm_flags & VM_SHARED);
98
99 if (write) {
100 sb_start_pagefault(inode->i_sb);
101 file_update_time(vmf->vma->vm_file);
102 }
103 down_read(&ei->dax_sem);
104
105 ret = dax_iomap_fault(vmf, PE_SIZE_PTE, NULL, NULL, &ext2_iomap_ops);
106
107 up_read(&ei->dax_sem);
108 if (write)
109 sb_end_pagefault(inode->i_sb);
110 return ret;
111}
112
113static const struct vm_operations_struct ext2_dax_vm_ops = {
114 .fault = ext2_dax_fault,
115 /*
116 * .huge_fault is not supported for DAX because allocation in ext2
117 * cannot be reliably aligned to huge page sizes and so pmd faults
118 * will always fail and fail back to regular faults.
119 */
120 .page_mkwrite = ext2_dax_fault,
121 .pfn_mkwrite = ext2_dax_fault,
122};
123
124static int ext2_file_mmap(struct file *file, struct vm_area_struct *vma)
125{
126 if (!IS_DAX(file_inode(file)))
127 return generic_file_mmap(file, vma);
128
129 file_accessed(file);
130 vma->vm_ops = &ext2_dax_vm_ops;
131 return 0;
132}
133#else
134#define ext2_file_mmap generic_file_mmap
135#endif
136
137/*
138 * Called when filp is released. This happens when all file descriptors
139 * for a single struct file are closed. Note that different open() calls
140 * for the same file yield different struct file structures.
141 */
142static int ext2_release_file (struct inode * inode, struct file * filp)
143{
144 if (filp->f_mode & FMODE_WRITE) {
145 mutex_lock(&EXT2_I(inode)->truncate_mutex);
146 ext2_discard_reservation(inode);
147 mutex_unlock(&EXT2_I(inode)->truncate_mutex);
148 }
149 return 0;
150}
151
152int ext2_fsync(struct file *file, loff_t start, loff_t end, int datasync)
153{
154 int ret;
155 struct super_block *sb = file->f_mapping->host->i_sb;
156
157 ret = generic_file_fsync(file, start, end, datasync);
158 if (ret == -EIO)
159 /* We don't really know where the IO error happened... */
160 ext2_error(sb, __func__,
161 "detected IO error when writing metadata buffers");
162 return ret;
163}
164
165static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
166{
167#ifdef CONFIG_FS_DAX
168 if (IS_DAX(iocb->ki_filp->f_mapping->host))
169 return ext2_dax_read_iter(iocb, to);
170#endif
171 return generic_file_read_iter(iocb, to);
172}
173
174static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
175{
176#ifdef CONFIG_FS_DAX
177 if (IS_DAX(iocb->ki_filp->f_mapping->host))
178 return ext2_dax_write_iter(iocb, from);
179#endif
180 return generic_file_write_iter(iocb, from);
181}
182
183const struct file_operations ext2_file_operations = {
184 .llseek = generic_file_llseek,
185 .read_iter = ext2_file_read_iter,
186 .write_iter = ext2_file_write_iter,
187 .unlocked_ioctl = ext2_ioctl,
188#ifdef CONFIG_COMPAT
189 .compat_ioctl = ext2_compat_ioctl,
190#endif
191 .mmap = ext2_file_mmap,
192 .open = dquot_file_open,
193 .release = ext2_release_file,
194 .fsync = ext2_fsync,
195 .get_unmapped_area = thp_get_unmapped_area,
196 .splice_read = generic_file_splice_read,
197 .splice_write = iter_file_splice_write,
198};
199
200const struct inode_operations ext2_file_inode_operations = {
201 .listxattr = ext2_listxattr,
202 .getattr = ext2_getattr,
203 .setattr = ext2_setattr,
204 .get_acl = ext2_get_acl,
205 .set_acl = ext2_set_acl,
206 .fiemap = ext2_fiemap,
207};