inode.c

  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_state_read_once(inode) & 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 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
 63		   S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
 64		inode->i_op = &jfs_file_inode_operations;
 65		init_special_inode(inode, inode->i_mode, inode->i_rdev);
 66	} else {
 67		printk(KERN_DEBUG "JFS: Invalid file type 0%04o for inode %lu.\n",
 68		       inode->i_mode, inode->i_ino);
 69		iget_failed(inode);
 70		return ERR_PTR(-EIO);
 71	}
 72	unlock_new_inode(inode);
 73	return inode;
 74}
 75
 76/*
 77 * Workhorse of both fsync & write_inode
 78 */
 79int jfs_commit_inode(struct inode *inode, int wait)
 80{
 81	int rc = 0;
 82	tid_t tid;
 83	static int noisy = 5;
 84
 85	jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
 86
 87	/*
 88	 * Don't commit if inode has been committed since last being
 89	 * marked dirty, or if it has been deleted.
 90	 */
 91	if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
 92		return 0;
 93
 94	if (isReadOnly(inode)) {
 95		/* kernel allows writes to devices on read-only
 96		 * partitions and may think inode is dirty
 97		 */
 98		if (!special_file(inode->i_mode) && noisy) {
 99			jfs_err("jfs_commit_inode(0x%p) called on read-only volume",
100				inode);
101			jfs_err("Is remount racy?");
102			noisy--;
103		}
104		return 0;
105	}
106
107	tid = txBegin(inode->i_sb, COMMIT_INODE);
108	mutex_lock(&JFS_IP(inode)->commit_mutex);
109
110	/*
111	 * Retest inode state after taking commit_mutex
112	 */
113	if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
114		rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
115
116	txEnd(tid);
117	mutex_unlock(&JFS_IP(inode)->commit_mutex);
118	return rc;
119}
120
121int jfs_write_inode(struct inode *inode, struct writeback_control *wbc)
122{
123	int wait = wbc->sync_mode == WB_SYNC_ALL;
124
125	if (inode->i_nlink == 0)
126		return 0;
127	/*
128	 * If COMMIT_DIRTY is not set, the inode isn't really dirty.
129	 * It has been committed since the last change, but was still
130	 * on the dirty inode list.
131	 */
132	if (!test_cflag(COMMIT_Dirty, inode)) {
133		/* Make sure committed changes hit the disk */
134		jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
135		return 0;
136	}
137
138	if (jfs_commit_inode(inode, wait)) {
139		jfs_err("jfs_write_inode: jfs_commit_inode failed!");
140		return -EIO;
141	} else
142		return 0;
143}
144
145void jfs_evict_inode(struct inode *inode)
146{
147	struct jfs_inode_info *ji = JFS_IP(inode);
148
149	jfs_info("In jfs_evict_inode, inode = 0x%p", inode);
150
151	if (!inode->i_nlink && !is_bad_inode(inode)) {
152		dquot_initialize(inode);
153
154		truncate_inode_pages_final(&inode->i_data);
155		if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
156			struct inode *ipimap = JFS_SBI(inode->i_sb)->ipimap;
157
158			if (test_cflag(COMMIT_Freewmap, inode))
159				jfs_free_zero_link(inode);
160
161			if (ipimap && JFS_IP(ipimap)->i_imap)
162				diFree(inode);
163
164			/*
165			 * Free the inode from the quota allocation.
166			 */
167			dquot_free_inode(inode);
168		}
169	} else {
170		truncate_inode_pages_final(&inode->i_data);
171	}
172	clear_inode(inode);
173	dquot_drop(inode);
174
175	BUG_ON(!list_empty(&ji->anon_inode_list));
176
177	spin_lock_irq(&ji->ag_lock);
178	if (ji->active_ag != -1) {
179		struct bmap *bmap = JFS_SBI(inode->i_sb)->bmap;
180		atomic_dec(&bmap->db_active[ji->active_ag]);
181		ji->active_ag = -1;
182	}
183	spin_unlock_irq(&ji->ag_lock);
184}
185
186void jfs_dirty_inode(struct inode *inode, int flags)
187{
188	static int noisy = 5;
189
190	if (isReadOnly(inode)) {
191		if (!special_file(inode->i_mode) && noisy) {
192			/* kernel allows writes to devices on read-only
193			 * partitions and may try to mark inode dirty
194			 */
195			jfs_err("jfs_dirty_inode called on read-only volume");
196			jfs_err("Is remount racy?");
197			noisy--;
198		}
199		return;
200	}
201
202	set_cflag(COMMIT_Dirty, inode);
203}
204
205int jfs_get_block(struct inode *ip, sector_t lblock,
206		  struct buffer_head *bh_result, int create)
207{
208	s64 lblock64 = lblock;
209	int rc = 0;
210	xad_t xad;
211	s64 xaddr;
212	int xflag;
213	s32 xlen = bh_result->b_size >> ip->i_blkbits;
214
215	/*
216	 * Take appropriate lock on inode
217	 */
218	if (create)
219		IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
220	else
221		IREAD_LOCK(ip, RDWRLOCK_NORMAL);
222
223	if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
224	    (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
225	    xaddr) {
226		if (xflag & XAD_NOTRECORDED) {
227			if (!create)
228				/*
229				 * Allocated but not recorded, read treats
230				 * this as a hole
231				 */
232				goto unlock;
233			XADoffset(&xad, lblock64);
234			XADlength(&xad, xlen);
235			XADaddress(&xad, xaddr);
236			rc = extRecord(ip, &xad);
237			if (rc)
238				goto unlock;
239			set_buffer_new(bh_result);
240		}
241
242		map_bh(bh_result, ip->i_sb, xaddr);
243		bh_result->b_size = xlen << ip->i_blkbits;
244		goto unlock;
245	}
246	if (!create)
247		goto unlock;
248
249	/*
250	 * Allocate a new block
251	 */
252	if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
253		goto unlock;
254	rc = extAlloc(ip, xlen, lblock64, &xad, false);
255	if (rc)
256		goto unlock;
257
258	set_buffer_new(bh_result);
259	map_bh(bh_result, ip->i_sb, addressXAD(&xad));
260	bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
261
262      unlock:
263	/*
264	 * Release lock on inode
265	 */
266	if (create)
267		IWRITE_UNLOCK(ip);
268	else
269		IREAD_UNLOCK(ip);
270	return rc;
271}
272
273static int jfs_writepages(struct address_space *mapping,
274			struct writeback_control *wbc)
275{
276	return mpage_writepages(mapping, wbc, jfs_get_block);
277}
278
279static int jfs_read_folio(struct file *file, struct folio *folio)
280{
281	return mpage_read_folio(folio, jfs_get_block);
282}
283
284static void jfs_readahead(struct readahead_control *rac)
285{
286	mpage_readahead(rac, jfs_get_block);
287}
288
289static void jfs_write_failed(struct address_space *mapping, loff_t to)
290{
291	struct inode *inode = mapping->host;
292
293	if (to > inode->i_size) {
294		truncate_pagecache(inode, inode->i_size);
295		jfs_truncate(inode);
296	}
297}
298
299static int jfs_write_begin(const struct kiocb *iocb,
300			   struct address_space *mapping,
301			   loff_t pos, unsigned len,
302			   struct folio **foliop, void **fsdata)
303{
304	int ret;
305
306	ret = block_write_begin(mapping, pos, len, foliop, jfs_get_block);
307	if (unlikely(ret))
308		jfs_write_failed(mapping, pos + len);
309
310	return ret;
311}
312
313static int jfs_write_end(const struct kiocb *iocb,
314			 struct address_space *mapping,
315			 loff_t pos, unsigned len, unsigned copied,
316			 struct folio *folio, void *fsdata)
317{
318	int ret;
319
320	ret = generic_write_end(iocb, mapping, pos, len, copied, folio, fsdata);
321	if (ret < len)
322		jfs_write_failed(mapping, pos + len);
323	return ret;
324}
325
326static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
327{
328	return generic_block_bmap(mapping, block, jfs_get_block);
329}
330
331static ssize_t jfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
332{
333	struct file *file = iocb->ki_filp;
334	struct address_space *mapping = file->f_mapping;
335	struct inode *inode = file->f_mapping->host;
336	size_t count = iov_iter_count(iter);
337	ssize_t ret;
338
339	ret = blockdev_direct_IO(iocb, inode, iter, jfs_get_block);
340
341	/*
342	 * In case of error extending write may have instantiated a few
343	 * blocks outside i_size. Trim these off again.
344	 */
345	if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
346		loff_t isize = i_size_read(inode);
347		loff_t end = iocb->ki_pos + count;
348
349		if (end > isize)
350			jfs_write_failed(mapping, end);
351	}
352
353	return ret;
354}
355
356const struct address_space_operations jfs_aops = {
357	.dirty_folio	= block_dirty_folio,
358	.invalidate_folio = block_invalidate_folio,
359	.read_folio	= jfs_read_folio,
360	.readahead	= jfs_readahead,
361	.writepages	= jfs_writepages,
362	.write_begin	= jfs_write_begin,
363	.write_end	= jfs_write_end,
364	.bmap		= jfs_bmap,
365	.direct_IO	= jfs_direct_IO,
366	.migrate_folio	= buffer_migrate_folio,
367};
368
369/*
370 * Guts of jfs_truncate.  Called with locks already held.  Can be called
371 * with directory for truncating directory index table.
372 */
373void jfs_truncate_nolock(struct inode *ip, loff_t length)
374{
375	loff_t newsize;
376	tid_t tid;
377
378	ASSERT(length >= 0);
379
380	if (test_cflag(COMMIT_Nolink, ip) || isReadOnly(ip)) {
381		xtTruncate(0, ip, length, COMMIT_WMAP);
382		return;
383	}
384
385	do {
386		tid = txBegin(ip->i_sb, 0);
387
388		/*
389		 * The commit_mutex cannot be taken before txBegin.
390		 * txBegin may block and there is a chance the inode
391		 * could be marked dirty and need to be committed
392		 * before txBegin unblocks
393		 */
394		mutex_lock(&JFS_IP(ip)->commit_mutex);
395
396		newsize = xtTruncate(tid, ip, length,
397				     COMMIT_TRUNCATE | COMMIT_PWMAP);
398		if (newsize < 0) {
399			txEnd(tid);
400			mutex_unlock(&JFS_IP(ip)->commit_mutex);
401			break;
402		}
403
404		inode_set_mtime_to_ts(ip, inode_set_ctime_current(ip));
405		mark_inode_dirty(ip);
406
407		txCommit(tid, 1, &ip, 0);
408		txEnd(tid);
409		mutex_unlock(&JFS_IP(ip)->commit_mutex);
410	} while (newsize > length);	/* Truncate isn't always atomic */
411}
412
413void jfs_truncate(struct inode *ip)
414{
415	jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
416
417	block_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
418
419	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
420	jfs_truncate_nolock(ip, ip->i_size);
421	IWRITE_UNLOCK(ip);
422}