xref: /openbmc/linux/fs/jfs/inode.c (revision 93d90ad7) 
1 /*
2  *   Copyright (C) International Business Machines Corp., 2000-2004
3  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
4  *
5  *   This program is free software;  you can redistribute it and/or modify
6  *   it under the terms of the GNU General Public License as published by
7  *   the Free Software Foundation; either version 2 of the License, or
8  *   (at your option) any later version.
9  *
10  *   This program is distributed in the hope that it will be useful,
11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
13  *   the GNU General Public License for more details.
14  *
15  *   You should have received a copy of the GNU General Public License
16  *   along with this program;  if not, write to the Free Software
17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 
20 #include <linux/fs.h>
21 #include <linux/mpage.h>
22 #include <linux/buffer_head.h>
23 #include <linux/pagemap.h>
24 #include <linux/quotaops.h>
25 #include <linux/writeback.h>
26 #include <linux/aio.h>
27 #include "jfs_incore.h"
28 #include "jfs_inode.h"
29 #include "jfs_filsys.h"
30 #include "jfs_imap.h"
31 #include "jfs_extent.h"
32 #include "jfs_unicode.h"
33 #include "jfs_debug.h"
34 
35 
36 struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
37 {
38 	struct inode *inode;
39 	int ret;
40 
41 	inode = iget_locked(sb, ino);
42 	if (!inode)
43 		return ERR_PTR(-ENOMEM);
44 	if (!(inode->i_state & I_NEW))
45 		return inode;
46 
47 	ret = diRead(inode);
48 	if (ret < 0) {
49 		iget_failed(inode);
50 		return ERR_PTR(ret);
51 	}
52 
53 	if (S_ISREG(inode->i_mode)) {
54 		inode->i_op = &jfs_file_inode_operations;
55 		inode->i_fop = &jfs_file_operations;
56 		inode->i_mapping->a_ops = &jfs_aops;
57 	} else if (S_ISDIR(inode->i_mode)) {
58 		inode->i_op = &jfs_dir_inode_operations;
59 		inode->i_fop = &jfs_dir_operations;
60 	} else if (S_ISLNK(inode->i_mode)) {
61 		if (inode->i_size >= IDATASIZE) {
62 			inode->i_op = &page_symlink_inode_operations;
63 			inode->i_mapping->a_ops = &jfs_aops;
64 		} else {
65 			inode->i_op = &jfs_fast_symlink_inode_operations;
66 			/*
67 			 * The inline data should be null-terminated, but
68 			 * don't let on-disk corruption crash the kernel
69 			 */
70 			JFS_IP(inode)->i_inline[inode->i_size] = '\0';
71 		}
72 	} else {
73 		inode->i_op = &jfs_file_inode_operations;
74 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
75 	}
76 	unlock_new_inode(inode);
77 	return inode;
78 }
79 
80 /*
81  * Workhorse of both fsync & write_inode
82  */
83 int jfs_commit_inode(struct inode *inode, int wait)
84 {
85 	int rc = 0;
86 	tid_t tid;
87 	static int noisy = 5;
88 
89 	jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
90 
91 	/*
92 	 * Don't commit if inode has been committed since last being
93 	 * marked dirty, or if it has been deleted.
94 	 */
95 	if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
96 		return 0;
97 
98 	if (isReadOnly(inode)) {
99 		/* kernel allows writes to devices on read-only
100 		 * partitions and may think inode is dirty
101 		 */
102 		if (!special_file(inode->i_mode) && noisy) {
103 			jfs_err("jfs_commit_inode(0x%p) called on "
104 				   "read-only volume", inode);
105 			jfs_err("Is remount racy?");
106 			noisy--;
107 		}
108 		return 0;
109 	}
110 
111 	tid = txBegin(inode->i_sb, COMMIT_INODE);
112 	mutex_lock(&JFS_IP(inode)->commit_mutex);
113 
114 	/*
115 	 * Retest inode state after taking commit_mutex
116 	 */
117 	if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
118 		rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
119 
120 	txEnd(tid);
121 	mutex_unlock(&JFS_IP(inode)->commit_mutex);
122 	return rc;
123 }
124 
125 int jfs_write_inode(struct inode *inode, struct writeback_control *wbc)
126 {
127 	int wait = wbc->sync_mode == WB_SYNC_ALL;
128 
129 	if (inode->i_nlink == 0)
130 		return 0;
131 	/*
132 	 * If COMMIT_DIRTY is not set, the inode isn't really dirty.
133 	 * It has been committed since the last change, but was still
134 	 * on the dirty inode list.
135 	 */
136 	 if (!test_cflag(COMMIT_Dirty, inode)) {
137 		/* Make sure committed changes hit the disk */
138 		jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
139 		return 0;
140 	 }
141 
142 	if (jfs_commit_inode(inode, wait)) {
143 		jfs_err("jfs_write_inode: jfs_commit_inode failed!");
144 		return -EIO;
145 	} else
146 		return 0;
147 }
148 
149 void jfs_evict_inode(struct inode *inode)
150 {
151 	jfs_info("In jfs_evict_inode, inode = 0x%p", inode);
152 
153 	if (!inode->i_nlink && !is_bad_inode(inode)) {
154 		dquot_initialize(inode);
155 
156 		if (JFS_IP(inode)->fileset == FILESYSTEM_I) {
157 			truncate_inode_pages_final(&inode->i_data);
158 
159 			if (test_cflag(COMMIT_Freewmap, inode))
160 				jfs_free_zero_link(inode);
161 
162 			diFree(inode);
163 
164 			/*
165 			 * Free the inode from the quota allocation.
166 			 */
167 			dquot_initialize(inode);
168 			dquot_free_inode(inode);
169 		}
170 	} else {
171 		truncate_inode_pages_final(&inode->i_data);
172 	}
173 	clear_inode(inode);
174 	dquot_drop(inode);
175 }
176 
177 void jfs_dirty_inode(struct inode *inode, int flags)
178 {
179 	static int noisy = 5;
180 
181 	if (isReadOnly(inode)) {
182 		if (!special_file(inode->i_mode) && noisy) {
183 			/* kernel allows writes to devices on read-only
184 			 * partitions and may try to mark inode dirty
185 			 */
186 			jfs_err("jfs_dirty_inode called on read-only volume");
187 			jfs_err("Is remount racy?");
188 			noisy--;
189 		}
190 		return;
191 	}
192 
193 	set_cflag(COMMIT_Dirty, inode);
194 }
195 
196 int jfs_get_block(struct inode *ip, sector_t lblock,
197 		  struct buffer_head *bh_result, int create)
198 {
199 	s64 lblock64 = lblock;
200 	int rc = 0;
201 	xad_t xad;
202 	s64 xaddr;
203 	int xflag;
204 	s32 xlen = bh_result->b_size >> ip->i_blkbits;
205 
206 	/*
207 	 * Take appropriate lock on inode
208 	 */
209 	if (create)
210 		IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
211 	else
212 		IREAD_LOCK(ip, RDWRLOCK_NORMAL);
213 
214 	if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
215 	    (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
216 	    xaddr) {
217 		if (xflag & XAD_NOTRECORDED) {
218 			if (!create)
219 				/*
220 				 * Allocated but not recorded, read treats
221 				 * this as a hole
222 				 */
223 				goto unlock;
224 #ifdef _JFS_4K
225 			XADoffset(&xad, lblock64);
226 			XADlength(&xad, xlen);
227 			XADaddress(&xad, xaddr);
228 #else				/* _JFS_4K */
229 			/*
230 			 * As long as block size = 4K, this isn't a problem.
231 			 * We should mark the whole page not ABNR, but how
232 			 * will we know to mark the other blocks BH_New?
233 			 */
234 			BUG();
235 #endif				/* _JFS_4K */
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 #ifdef _JFS_4K
253 	if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
254 		goto unlock;
255 	rc = extAlloc(ip, xlen, lblock64, &xad, false);
256 	if (rc)
257 		goto unlock;
258 
259 	set_buffer_new(bh_result);
260 	map_bh(bh_result, ip->i_sb, addressXAD(&xad));
261 	bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
262 
263 #else				/* _JFS_4K */
264 	/*
265 	 * We need to do whatever it takes to keep all but the last buffers
266 	 * in 4K pages - see jfs_write.c
267 	 */
268 	BUG();
269 #endif				/* _JFS_4K */
270 
271       unlock:
272 	/*
273 	 * Release lock on inode
274 	 */
275 	if (create)
276 		IWRITE_UNLOCK(ip);
277 	else
278 		IREAD_UNLOCK(ip);
279 	return rc;
280 }
281 
282 static int jfs_writepage(struct page *page, struct writeback_control *wbc)
283 {
284 	return block_write_full_page(page, jfs_get_block, wbc);
285 }
286 
287 static int jfs_writepages(struct address_space *mapping,
288 			struct writeback_control *wbc)
289 {
290 	return mpage_writepages(mapping, wbc, jfs_get_block);
291 }
292 
293 static int jfs_readpage(struct file *file, struct page *page)
294 {
295 	return mpage_readpage(page, jfs_get_block);
296 }
297 
298 static int jfs_readpages(struct file *file, struct address_space *mapping,
299 		struct list_head *pages, unsigned nr_pages)
300 {
301 	return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
302 }
303 
304 static void jfs_write_failed(struct address_space *mapping, loff_t to)
305 {
306 	struct inode *inode = mapping->host;
307 
308 	if (to > inode->i_size) {
309 		truncate_pagecache(inode, inode->i_size);
310 		jfs_truncate(inode);
311 	}
312 }
313 
314 static int jfs_write_begin(struct file *file, struct address_space *mapping,
315 				loff_t pos, unsigned len, unsigned flags,
316 				struct page **pagep, void **fsdata)
317 {
318 	int ret;
319 
320 	ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
321 				jfs_get_block);
322 	if (unlikely(ret))
323 		jfs_write_failed(mapping, pos + len);
324 
325 	return ret;
326 }
327 
328 static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
329 {
330 	return generic_block_bmap(mapping, block, jfs_get_block);
331 }
332 
333 static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
334 	struct iov_iter *iter, loff_t offset)
335 {
336 	struct file *file = iocb->ki_filp;
337 	struct address_space *mapping = file->f_mapping;
338 	struct inode *inode = file->f_mapping->host;
339 	size_t count = iov_iter_count(iter);
340 	ssize_t ret;
341 
342 	ret = blockdev_direct_IO(rw, iocb, inode, iter, offset, jfs_get_block);
343 
344 	/*
345 	 * In case of error extending write may have instantiated a few
346 	 * blocks outside i_size. Trim these off again.
347 	 */
348 	if (unlikely((rw & WRITE) && ret < 0)) {
349 		loff_t isize = i_size_read(inode);
350 		loff_t end = offset + count;
351 
352 		if (end > isize)
353 			jfs_write_failed(mapping, end);
354 	}
355 
356 	return ret;
357 }
358 
359 const struct address_space_operations jfs_aops = {
360 	.readpage	= jfs_readpage,
361 	.readpages	= jfs_readpages,
362 	.writepage	= jfs_writepage,
363 	.writepages	= jfs_writepages,
364 	.write_begin	= jfs_write_begin,
365 	.write_end	= nobh_write_end,
366 	.bmap		= jfs_bmap,
367 	.direct_IO	= jfs_direct_IO,
368 };
369 
370 /*
371  * Guts of jfs_truncate.  Called with locks already held.  Can be called
372  * with directory for truncating directory index table.
373  */
374 void jfs_truncate_nolock(struct inode *ip, loff_t length)
375 {
376 	loff_t newsize;
377 	tid_t tid;
378 
379 	ASSERT(length >= 0);
380 
381 	if (test_cflag(COMMIT_Nolink, ip)) {
382 		xtTruncate(0, ip, length, COMMIT_WMAP);
383 		return;
384 	}
385 
386 	do {
387 		tid = txBegin(ip->i_sb, 0);
388 
389 		/*
390 		 * The commit_mutex cannot be taken before txBegin.
391 		 * txBegin may block and there is a chance the inode
392 		 * could be marked dirty and need to be committed
393 		 * before txBegin unblocks
394 		 */
395 		mutex_lock(&JFS_IP(ip)->commit_mutex);
396 
397 		newsize = xtTruncate(tid, ip, length,
398 				     COMMIT_TRUNCATE | COMMIT_PWMAP);
399 		if (newsize < 0) {
400 			txEnd(tid);
401 			mutex_unlock(&JFS_IP(ip)->commit_mutex);
402 			break;
403 		}
404 
405 		ip->i_mtime = ip->i_ctime = CURRENT_TIME;
406 		mark_inode_dirty(ip);
407 
408 		txCommit(tid, 1, &ip, 0);
409 		txEnd(tid);
410 		mutex_unlock(&JFS_IP(ip)->commit_mutex);
411 	} while (newsize > length);	/* Truncate isn't always atomic */
412 }
413 
414 void jfs_truncate(struct inode *ip)
415 {
416 	jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
417 
418 	nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
419 
420 	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
421 	jfs_truncate_nolock(ip, ip->i_size);
422 	IWRITE_UNLOCK(ip);
423 }
424