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(-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(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(&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(JFS_SBI(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(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(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(&ji->ag_lock);
172	if (ji->active_ag != -1) {
173		struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
174		atomic_dec(&bmap->db_active[ji->active_ag]);
175		ji->active_ag = -1;
176	}
177	spin_unlock_irq(&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, lblock64, xlen, &xflag, &xaddr, &xlen, 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_result, ip->i_sb, 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_result, 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, jfs_get_block);
271}
272
273static int jfs_read_folio(struct file *file, struct folio *folio)
274{
275	return mpage_read_folio(folio, jfs_get_block);
276}
277
278static void jfs_readahead(struct readahead_control *rac)
279{
280	mpage_readahead(rac, 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, 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, jfs_get_block);
300	if (unlikely(ret))
301		jfs_write_failed(mapping, 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, 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(iter);
329	ssize_t ret;
330
331	ret = blockdev_direct_IO(iocb, inode, iter, 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, 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(0, ip, 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, length,
389				     COMMIT_TRUNCATE | COMMIT_PWMAP);
390		if (newsize < 0) {
391			txEnd(tid);
392			mutex_unlock(&JFS_IP(ip)->commit_mutex);
393			break;
394		}
395
396		inode_set_mtime_to_ts(ip, inode_set_ctime_current(ip));
397		mark_inode_dirty(ip);
398
399		txCommit(tid, 1, &ip, 0);
400		txEnd(tid);
401		mutex_unlock(&JFS_IP(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, ip->i_size);
413	IWRITE_UNLOCK(ip);
414}
415