xref: /linux/fs/jfs/inode.c (revision 4359a011e259a4608afc7fb3635370c9d4ba5943) 
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 
24 struct 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  */
73 int 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 
115 int 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 
139 void 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 
180 void 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 
199 int 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 
267 static int jfs_writepage(struct page *page, struct writeback_control *wbc)
268 {
269 	return block_write_full_page(page, jfs_get_block, wbc);
270 }
271 
272 static int jfs_writepages(struct address_space *mapping,
273 			struct writeback_control *wbc)
274 {
275 	return mpage_writepages(mapping, wbc, jfs_get_block);
276 }
277 
278 static int jfs_read_folio(struct file *file, struct folio *folio)
279 {
280 	return mpage_read_folio(folio, jfs_get_block);
281 }
282 
283 static void jfs_readahead(struct readahead_control *rac)
284 {
285 	mpage_readahead(rac, jfs_get_block);
286 }
287 
288 static void jfs_write_failed(struct address_space *mapping, loff_t to)
289 {
290 	struct inode *inode = mapping->host;
291 
292 	if (to > inode->i_size) {
293 		truncate_pagecache(inode, inode->i_size);
294 		jfs_truncate(inode);
295 	}
296 }
297 
298 static int jfs_write_begin(struct file *file, struct address_space *mapping,
299 				loff_t pos, unsigned len,
300 				struct page **pagep, void **fsdata)
301 {
302 	int ret;
303 
304 	ret = block_write_begin(mapping, pos, len, pagep, jfs_get_block);
305 	if (unlikely(ret))
306 		jfs_write_failed(mapping, pos + len);
307 
308 	return ret;
309 }
310 
311 static int jfs_write_end(struct file *file, struct address_space *mapping,
312 		loff_t pos, unsigned len, unsigned copied, struct page *page,
313 		void *fsdata)
314 {
315 	int ret;
316 
317 	ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
318 	if (ret < len)
319 		jfs_write_failed(mapping, pos + len);
320 	return ret;
321 }
322 
323 static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
324 {
325 	return generic_block_bmap(mapping, block, jfs_get_block);
326 }
327 
328 static ssize_t jfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
329 {
330 	struct file *file = iocb->ki_filp;
331 	struct address_space *mapping = file->f_mapping;
332 	struct inode *inode = file->f_mapping->host;
333 	size_t count = iov_iter_count(iter);
334 	ssize_t ret;
335 
336 	ret = blockdev_direct_IO(iocb, inode, iter, jfs_get_block);
337 
338 	/*
339 	 * In case of error extending write may have instantiated a few
340 	 * blocks outside i_size. Trim these off again.
341 	 */
342 	if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
343 		loff_t isize = i_size_read(inode);
344 		loff_t end = iocb->ki_pos + count;
345 
346 		if (end > isize)
347 			jfs_write_failed(mapping, end);
348 	}
349 
350 	return ret;
351 }
352 
353 const struct address_space_operations jfs_aops = {
354 	.dirty_folio	= block_dirty_folio,
355 	.invalidate_folio = block_invalidate_folio,
356 	.read_folio	= jfs_read_folio,
357 	.readahead	= jfs_readahead,
358 	.writepage	= jfs_writepage,
359 	.writepages	= jfs_writepages,
360 	.write_begin	= jfs_write_begin,
361 	.write_end	= jfs_write_end,
362 	.bmap		= jfs_bmap,
363 	.direct_IO	= jfs_direct_IO,
364 };
365 
366 /*
367  * Guts of jfs_truncate.  Called with locks already held.  Can be called
368  * with directory for truncating directory index table.
369  */
370 void jfs_truncate_nolock(struct inode *ip, loff_t length)
371 {
372 	loff_t newsize;
373 	tid_t tid;
374 
375 	ASSERT(length >= 0);
376 
377 	if (test_cflag(COMMIT_Nolink, ip)) {
378 		xtTruncate(0, ip, length, COMMIT_WMAP);
379 		return;
380 	}
381 
382 	do {
383 		tid = txBegin(ip->i_sb, 0);
384 
385 		/*
386 		 * The commit_mutex cannot be taken before txBegin.
387 		 * txBegin may block and there is a chance the inode
388 		 * could be marked dirty and need to be committed
389 		 * before txBegin unblocks
390 		 */
391 		mutex_lock(&JFS_IP(ip)->commit_mutex);
392 
393 		newsize = xtTruncate(tid, ip, length,
394 				     COMMIT_TRUNCATE | COMMIT_PWMAP);
395 		if (newsize < 0) {
396 			txEnd(tid);
397 			mutex_unlock(&JFS_IP(ip)->commit_mutex);
398 			break;
399 		}
400 
401 		ip->i_mtime = ip->i_ctime = current_time(ip);
402 		mark_inode_dirty(ip);
403 
404 		txCommit(tid, 1, &ip, 0);
405 		txEnd(tid);
406 		mutex_unlock(&JFS_IP(ip)->commit_mutex);
407 	} while (newsize > length);	/* Truncate isn't always atomic */
408 }
409 
410 void jfs_truncate(struct inode *ip)
411 {
412 	jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
413 
414 	block_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
415 
416 	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
417 	jfs_truncate_nolock(ip, ip->i_size);
418 	IWRITE_UNLOCK(ip);
419 }
420