interconnect: qcom: icc-rpm: Fix peak rate calculation
[linux-2.6-microblaze.git] / fs / ext2 / file.c
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
35 static 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
51 static 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
74 out_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  */
93 static 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
114 static 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
125 static 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  */
143 static 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
153 int 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
166 static 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
181 static 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         }
203 out:
204         trace_ext2_dio_write_endio(iocb, size, error);
205         return error;
206 }
207
208 static const struct iomap_dio_ops ext2_dio_write_ops = {
209         .end_io = ext2_dio_write_end_io,
210 };
211
212 static 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                 iocb->ki_pos += status;
262                 ret += status;
263                 endbyte = pos + status - 1;
264                 ret2 = filemap_write_and_wait_range(inode->i_mapping, pos,
265                                                     endbyte);
266                 if (!ret2)
267                         invalidate_mapping_pages(inode->i_mapping,
268                                                  pos >> PAGE_SHIFT,
269                                                  endbyte >> PAGE_SHIFT);
270                 if (ret > 0)
271                         generic_write_sync(iocb, ret);
272         }
273
274 out_unlock:
275         inode_unlock(inode);
276         if (status)
277                 trace_ext2_dio_write_buff_end(iocb, from, status);
278         trace_ext2_dio_write_end(iocb, from, ret);
279         return ret;
280 }
281
282 static ssize_t ext2_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
283 {
284 #ifdef CONFIG_FS_DAX
285         if (IS_DAX(iocb->ki_filp->f_mapping->host))
286                 return ext2_dax_read_iter(iocb, to);
287 #endif
288         if (iocb->ki_flags & IOCB_DIRECT)
289                 return ext2_dio_read_iter(iocb, to);
290
291         return generic_file_read_iter(iocb, to);
292 }
293
294 static ssize_t ext2_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
295 {
296 #ifdef CONFIG_FS_DAX
297         if (IS_DAX(iocb->ki_filp->f_mapping->host))
298                 return ext2_dax_write_iter(iocb, from);
299 #endif
300         if (iocb->ki_flags & IOCB_DIRECT)
301                 return ext2_dio_write_iter(iocb, from);
302
303         return generic_file_write_iter(iocb, from);
304 }
305
306 const struct file_operations ext2_file_operations = {
307         .llseek         = generic_file_llseek,
308         .read_iter      = ext2_file_read_iter,
309         .write_iter     = ext2_file_write_iter,
310         .unlocked_ioctl = ext2_ioctl,
311 #ifdef CONFIG_COMPAT
312         .compat_ioctl   = ext2_compat_ioctl,
313 #endif
314         .mmap           = ext2_file_mmap,
315         .open           = dquot_file_open,
316         .release        = ext2_release_file,
317         .fsync          = ext2_fsync,
318         .get_unmapped_area = thp_get_unmapped_area,
319         .splice_read    = filemap_splice_read,
320         .splice_write   = iter_file_splice_write,
321 };
322
323 const struct inode_operations ext2_file_inode_operations = {
324         .listxattr      = ext2_listxattr,
325         .getattr        = ext2_getattr,
326         .setattr        = ext2_setattr,
327         .get_inode_acl  = ext2_get_acl,
328         .set_acl        = ext2_set_acl,
329         .fiemap         = ext2_fiemap,
330         .fileattr_get   = ext2_fileattr_get,
331         .fileattr_set   = ext2_fileattr_set,
332 };