1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (C) International Business Machines Corp., 2000-2004
4 * Portions Copyright (C) Christoph Hellwig, 2001-2002
5 */
6
7#include <linux/fs.h>
8#include <linux/mpage.h>
9#include <linux/buffer_head.h>
10#include <linux/pagemap.h>
11#include <linux/quotaops.h>
12#include <linux/uio.h>
13#include <linux/writeback.h>
14#include "jfs_incore.h"
15#include "jfs_inode.h"
16#include "jfs_filsys.h"
17#include "jfs_imap.h"
18#include "jfs_extent.h"
19#include "jfs_unicode.h"
20#include "jfs_debug.h"
21#include "jfs_dmap.h"
22
23
24struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
25{
26 struct inode *inode;
27 int ret;
28
29 inode = iget_locked(sb, ino);
30 if (!inode)
31 return ERR_PTR(error: -ENOMEM);
32 if (!(inode->i_state & I_NEW))
33 return inode;
34
35 ret = diRead(inode);
36 if (ret < 0) {
37 iget_failed(inode);
38 return ERR_PTR(error: ret);
39 }
40
41 if (S_ISREG(inode->i_mode)) {
42 inode->i_op = &jfs_file_inode_operations;
43 inode->i_fop = &jfs_file_operations;
44 inode->i_mapping->a_ops = &jfs_aops;
45 } else if (S_ISDIR(inode->i_mode)) {
46 inode->i_op = &jfs_dir_inode_operations;
47 inode->i_fop = &jfs_dir_operations;
48 } else if (S_ISLNK(inode->i_mode)) {
49 if (inode->i_size >= IDATASIZE) {
50 inode->i_op = &page_symlink_inode_operations;
51 inode_nohighmem(inode);
52 inode->i_mapping->a_ops = &jfs_aops;
53 } else {
54 inode->i_op = &jfs_fast_symlink_inode_operations;
55 inode->i_link = JFS_IP(inode)->i_inline;
56 /*
57 * The inline data should be null-terminated, but
58 * don't let on-disk corruption crash the kernel
59 */
60 inode->i_link[inode->i_size] = '\0';
61 }
62 } else {
63 inode->i_op = &jfs_file_inode_operations;
64 init_special_inode(inode, inode->i_mode, inode->i_rdev);
65 }
66 unlock_new_inode(inode);
67 return inode;
68}
69
70/*
71 * Workhorse of both fsync & write_inode
72 */
73int jfs_commit_inode(struct inode *inode, int wait)
74{
75 int rc = 0;
76 tid_t tid;
77 static int noisy = 5;
78
79 jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
80
81 /*
82 * Don't commit if inode has been committed since last being
83 * marked dirty, or if it has been deleted.
84 */
85 if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
86 return 0;
87
88 if (isReadOnly(inode)) {
89 /* kernel allows writes to devices on read-only
90 * partitions and may think inode is dirty
91 */
92 if (!special_file(inode->i_mode) && noisy) {
93 jfs_err("jfs_commit_inode(0x%p) called on read-only volume",
94 inode);
95 jfs_err("Is remount racy?");
96 noisy--;
97 }
98 return 0;
99 }
100
101 tid = txBegin(inode->i_sb, COMMIT_INODE);
102 mutex_lock(&JFS_IP(inode)->commit_mutex);
103
104 /*
105 * Retest inode state after taking commit_mutex
106 */
107 if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
108 rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
109
110 txEnd(tid);
111 mutex_unlock(lock: &JFS_IP(inode)->commit_mutex);
112 return rc;
113}
114
115int jfs_write_inode(struct inode *inode, struct writeback_control *wbc)
116{
117 int wait = wbc->sync_mode == WB_SYNC_ALL;
118
119 if (inode->i_nlink == 0)
120 return 0;
121 /*
122 * If COMMIT_DIRTY is not set, the inode isn't really dirty.
123 * It has been committed since the last change, but was still
124 * on the dirty inode list.
125 */
126 if (!test_cflag(COMMIT_Dirty, inode)) {
127 /* Make sure committed changes hit the disk */
128 jfs_flush_journal(log: JFS_SBI(sb: inode->i_sb)->log, wait);
129 return 0;
130 }
131
132 if (jfs_commit_inode(inode, wait)) {
133 jfs_err("jfs_write_inode: jfs_commit_inode failed!");
134 return -EIO;
135 } else
136 return 0;
137}
138
139void jfs_evict_inode(struct inode *inode)
140{
141 struct jfs_inode_info *ji = JFS_IP(inode);
142
143 jfs_info("In jfs_evict_inode, inode = 0x%p", inode);
144
145 if (!inode->i_nlink && !is_bad_inode(inode)) {
146 dquot_initialize(inode);
147
148 if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
149 struct inode *ipimap = JFS_SBI(sb: inode->i_sb)->ipimap;
150 truncate_inode_pages_final(&inode->i_data);
151
152 if (test_cflag(COMMIT_Freewmap, inode))
153 jfs_free_zero_link(inode);
154
155 if (ipimap && JFS_IP(inode: ipimap)->i_imap)
156 diFree(inode);
157
158 /*
159 * Free the inode from the quota allocation.
160 */
161 dquot_free_inode(inode);
162 }
163 } else {
164 truncate_inode_pages_final(&inode->i_data);
165 }
166 clear_inode(inode);
167 dquot_drop(inode);
168
169 BUG_ON(!list_empty(&ji->anon_inode_list));
170
171 spin_lock_irq(lock: &ji->ag_lock);
172 if (ji->active_ag != -1) {
173 struct bmap *bmap = JFS_SBI(sb: inode->i_sb)->bmap;
174 atomic_dec(v: &bmap->db_active[ji->active_ag]);
175 ji->active_ag = -1;
176 }
177 spin_unlock_irq(lock: &ji->ag_lock);
178}
179
180void jfs_dirty_inode(struct inode *inode, int flags)
181{
182 static int noisy = 5;
183
184 if (isReadOnly(inode)) {
185 if (!special_file(inode->i_mode) && noisy) {
186 /* kernel allows writes to devices on read-only
187 * partitions and may try to mark inode dirty
188 */
189 jfs_err("jfs_dirty_inode called on read-only volume");
190 jfs_err("Is remount racy?");
191 noisy--;
192 }
193 return;
194 }
195
196 set_cflag(COMMIT_Dirty, inode);
197}
198
199int jfs_get_block(struct inode *ip, sector_t lblock,
200 struct buffer_head *bh_result, int create)
201{
202 s64 lblock64 = lblock;
203 int rc = 0;
204 xad_t xad;
205 s64 xaddr;
206 int xflag;
207 s32 xlen = bh_result->b_size >> ip->i_blkbits;
208
209 /*
210 * Take appropriate lock on inode
211 */
212 if (create)
213 IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
214 else
215 IREAD_LOCK(ip, RDWRLOCK_NORMAL);
216
217 if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
218 (!xtLookup(ip, lstart: lblock64, llen: xlen, pflag: &xflag, paddr: &xaddr, plen: &xlen, flag: 0)) &&
219 xaddr) {
220 if (xflag & XAD_NOTRECORDED) {
221 if (!create)
222 /*
223 * Allocated but not recorded, read treats
224 * this as a hole
225 */
226 goto unlock;
227 XADoffset(&xad, lblock64);
228 XADlength(&xad, xlen);
229 XADaddress(&xad, xaddr);
230 rc = extRecord(ip, &xad);
231 if (rc)
232 goto unlock;
233 set_buffer_new(bh_result);
234 }
235
236 map_bh(bh: bh_result, sb: ip->i_sb, block: xaddr);
237 bh_result->b_size = xlen << ip->i_blkbits;
238 goto unlock;
239 }
240 if (!create)
241 goto unlock;
242
243 /*
244 * Allocate a new block
245 */
246 if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
247 goto unlock;
248 rc = extAlloc(ip, xlen, lblock64, &xad, false);
249 if (rc)
250 goto unlock;
251
252 set_buffer_new(bh_result);
253 map_bh(bh: bh_result, sb: ip->i_sb, addressXAD(&xad));
254 bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
255
256 unlock:
257 /*
258 * Release lock on inode
259 */
260 if (create)
261 IWRITE_UNLOCK(ip);
262 else
263 IREAD_UNLOCK(ip);
264 return rc;
265}
266
267static int jfs_writepages(struct address_space *mapping,
268 struct writeback_control *wbc)
269{
270 return mpage_writepages(mapping, wbc, get_block: jfs_get_block);
271}
272
273static int jfs_read_folio(struct file *file, struct folio *folio)
274{
275 return mpage_read_folio(folio, get_block: jfs_get_block);
276}
277
278static void jfs_readahead(struct readahead_control *rac)
279{
280 mpage_readahead(rac, get_block: jfs_get_block);
281}
282
283static void jfs_write_failed(struct address_space *mapping, loff_t to)
284{
285 struct inode *inode = mapping->host;
286
287 if (to > inode->i_size) {
288 truncate_pagecache(inode, new: inode->i_size);
289 jfs_truncate(inode);
290 }
291}
292
293static int jfs_write_begin(struct file *file, struct address_space *mapping,
294 loff_t pos, unsigned len,
295 struct page **pagep, void **fsdata)
296{
297 int ret;
298
299 ret = block_write_begin(mapping, pos, len, pagep, get_block: jfs_get_block);
300 if (unlikely(ret))
301 jfs_write_failed(mapping, to: pos + len);
302
303 return ret;
304}
305
306static int jfs_write_end(struct file *file, struct address_space *mapping,
307 loff_t pos, unsigned len, unsigned copied, struct page *page,
308 void *fsdata)
309{
310 int ret;
311
312 ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
313 if (ret < len)
314 jfs_write_failed(mapping, to: pos + len);
315 return ret;
316}
317
318static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
319{
320 return generic_block_bmap(mapping, block, jfs_get_block);
321}
322
323static ssize_t jfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
324{
325 struct file *file = iocb->ki_filp;
326 struct address_space *mapping = file->f_mapping;
327 struct inode *inode = file->f_mapping->host;
328 size_t count = iov_iter_count(i: iter);
329 ssize_t ret;
330
331 ret = blockdev_direct_IO(iocb, inode, iter, get_block: jfs_get_block);
332
333 /*
334 * In case of error extending write may have instantiated a few
335 * blocks outside i_size. Trim these off again.
336 */
337 if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
338 loff_t isize = i_size_read(inode);
339 loff_t end = iocb->ki_pos + count;
340
341 if (end > isize)
342 jfs_write_failed(mapping, to: end);
343 }
344
345 return ret;
346}
347
348const struct address_space_operations jfs_aops = {
349 .dirty_folio = block_dirty_folio,
350 .invalidate_folio = block_invalidate_folio,
351 .read_folio = jfs_read_folio,
352 .readahead = jfs_readahead,
353 .writepages = jfs_writepages,
354 .write_begin = jfs_write_begin,
355 .write_end = jfs_write_end,
356 .bmap = jfs_bmap,
357 .direct_IO = jfs_direct_IO,
358 .migrate_folio = buffer_migrate_folio,
359};
360
361/*
362 * Guts of jfs_truncate. Called with locks already held. Can be called
363 * with directory for truncating directory index table.
364 */
365void jfs_truncate_nolock(struct inode *ip, loff_t length)
366{
367 loff_t newsize;
368 tid_t tid;
369
370 ASSERT(length >= 0);
371
372 if (test_cflag(COMMIT_Nolink, ip)) {
373 xtTruncate(tid: 0, ip, newsize: length, COMMIT_WMAP);
374 return;
375 }
376
377 do {
378 tid = txBegin(ip->i_sb, 0);
379
380 /*
381 * The commit_mutex cannot be taken before txBegin.
382 * txBegin may block and there is a chance the inode
383 * could be marked dirty and need to be committed
384 * before txBegin unblocks
385 */
386 mutex_lock(&JFS_IP(ip)->commit_mutex);
387
388 newsize = xtTruncate(tid, ip, newsize: length,
389 COMMIT_TRUNCATE | COMMIT_PWMAP);
390 if (newsize < 0) {
391 txEnd(tid);
392 mutex_unlock(lock: &JFS_IP(inode: ip)->commit_mutex);
393 break;
394 }
395
396 inode_set_mtime_to_ts(inode: ip, ts: inode_set_ctime_current(inode: ip));
397 mark_inode_dirty(inode: ip);
398
399 txCommit(tid, 1, &ip, 0);
400 txEnd(tid);
401 mutex_unlock(lock: &JFS_IP(inode: ip)->commit_mutex);
402 } while (newsize > length); /* Truncate isn't always atomic */
403}
404
405void jfs_truncate(struct inode *ip)
406{
407 jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
408
409 block_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
410
411 IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
412 jfs_truncate_nolock(ip, length: ip->i_size);
413 IWRITE_UNLOCK(ip);
414}
415

source code of linux/fs/jfs/inode.c