xref: /openbmc/linux/fs/jfs/inode.c (revision 64c70b1c)
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 "jfs_incore.h"
26 #include "jfs_inode.h"
27 #include "jfs_filsys.h"
28 #include "jfs_imap.h"
29 #include "jfs_extent.h"
30 #include "jfs_unicode.h"
31 #include "jfs_debug.h"
32 
33 
34 void jfs_read_inode(struct inode *inode)
35 {
36 	if (diRead(inode)) {
37 		make_bad_inode(inode);
38 		return;
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->i_mapping->a_ops = &jfs_aops;
52 		} else
53 			inode->i_op = &jfs_symlink_inode_operations;
54 	} else {
55 		inode->i_op = &jfs_file_inode_operations;
56 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
57 	}
58 }
59 
60 /*
61  * Workhorse of both fsync & write_inode
62  */
63 int jfs_commit_inode(struct inode *inode, int wait)
64 {
65 	int rc = 0;
66 	tid_t tid;
67 	static int noisy = 5;
68 
69 	jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
70 
71 	/*
72 	 * Don't commit if inode has been committed since last being
73 	 * marked dirty, or if it has been deleted.
74 	 */
75 	if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
76 		return 0;
77 
78 	if (isReadOnly(inode)) {
79 		/* kernel allows writes to devices on read-only
80 		 * partitions and may think inode is dirty
81 		 */
82 		if (!special_file(inode->i_mode) && noisy) {
83 			jfs_err("jfs_commit_inode(0x%p) called on "
84 				   "read-only volume", inode);
85 			jfs_err("Is remount racy?");
86 			noisy--;
87 		}
88 		return 0;
89 	}
90 
91 	tid = txBegin(inode->i_sb, COMMIT_INODE);
92 	mutex_lock(&JFS_IP(inode)->commit_mutex);
93 
94 	/*
95 	 * Retest inode state after taking commit_mutex
96 	 */
97 	if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
98 		rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
99 
100 	txEnd(tid);
101 	mutex_unlock(&JFS_IP(inode)->commit_mutex);
102 	return rc;
103 }
104 
105 int jfs_write_inode(struct inode *inode, int wait)
106 {
107 	if (test_cflag(COMMIT_Nolink, inode))
108 		return 0;
109 	/*
110 	 * If COMMIT_DIRTY is not set, the inode isn't really dirty.
111 	 * It has been committed since the last change, but was still
112 	 * on the dirty inode list.
113 	 */
114 	 if (!test_cflag(COMMIT_Dirty, inode)) {
115 		/* Make sure committed changes hit the disk */
116 		jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
117 		return 0;
118 	 }
119 
120 	if (jfs_commit_inode(inode, wait)) {
121 		jfs_err("jfs_write_inode: jfs_commit_inode failed!");
122 		return -EIO;
123 	} else
124 		return 0;
125 }
126 
127 void jfs_delete_inode(struct inode *inode)
128 {
129 	jfs_info("In jfs_delete_inode, inode = 0x%p", inode);
130 
131 	if (!is_bad_inode(inode) &&
132 	    (JFS_IP(inode)->fileset == FILESYSTEM_I)) {
133 		truncate_inode_pages(&inode->i_data, 0);
134 
135 		if (test_cflag(COMMIT_Freewmap, inode))
136 			jfs_free_zero_link(inode);
137 
138 		diFree(inode);
139 
140 		/*
141 		 * Free the inode from the quota allocation.
142 		 */
143 		DQUOT_INIT(inode);
144 		DQUOT_FREE_INODE(inode);
145 		DQUOT_DROP(inode);
146 	}
147 
148 	clear_inode(inode);
149 }
150 
151 void jfs_dirty_inode(struct inode *inode)
152 {
153 	static int noisy = 5;
154 
155 	if (isReadOnly(inode)) {
156 		if (!special_file(inode->i_mode) && noisy) {
157 			/* kernel allows writes to devices on read-only
158 			 * partitions and may try to mark inode dirty
159 			 */
160 			jfs_err("jfs_dirty_inode called on read-only volume");
161 			jfs_err("Is remount racy?");
162 			noisy--;
163 		}
164 		return;
165 	}
166 
167 	set_cflag(COMMIT_Dirty, inode);
168 }
169 
170 int jfs_get_block(struct inode *ip, sector_t lblock,
171 		  struct buffer_head *bh_result, int create)
172 {
173 	s64 lblock64 = lblock;
174 	int rc = 0;
175 	xad_t xad;
176 	s64 xaddr;
177 	int xflag;
178 	s32 xlen = bh_result->b_size >> ip->i_blkbits;
179 
180 	/*
181 	 * Take appropriate lock on inode
182 	 */
183 	if (create)
184 		IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
185 	else
186 		IREAD_LOCK(ip, RDWRLOCK_NORMAL);
187 
188 	if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
189 	    (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
190 	    xaddr) {
191 		if (xflag & XAD_NOTRECORDED) {
192 			if (!create)
193 				/*
194 				 * Allocated but not recorded, read treats
195 				 * this as a hole
196 				 */
197 				goto unlock;
198 #ifdef _JFS_4K
199 			XADoffset(&xad, lblock64);
200 			XADlength(&xad, xlen);
201 			XADaddress(&xad, xaddr);
202 #else				/* _JFS_4K */
203 			/*
204 			 * As long as block size = 4K, this isn't a problem.
205 			 * We should mark the whole page not ABNR, but how
206 			 * will we know to mark the other blocks BH_New?
207 			 */
208 			BUG();
209 #endif				/* _JFS_4K */
210 			rc = extRecord(ip, &xad);
211 			if (rc)
212 				goto unlock;
213 			set_buffer_new(bh_result);
214 		}
215 
216 		map_bh(bh_result, ip->i_sb, xaddr);
217 		bh_result->b_size = xlen << ip->i_blkbits;
218 		goto unlock;
219 	}
220 	if (!create)
221 		goto unlock;
222 
223 	/*
224 	 * Allocate a new block
225 	 */
226 #ifdef _JFS_4K
227 	if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
228 		goto unlock;
229 	rc = extAlloc(ip, xlen, lblock64, &xad, false);
230 	if (rc)
231 		goto unlock;
232 
233 	set_buffer_new(bh_result);
234 	map_bh(bh_result, ip->i_sb, addressXAD(&xad));
235 	bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
236 
237 #else				/* _JFS_4K */
238 	/*
239 	 * We need to do whatever it takes to keep all but the last buffers
240 	 * in 4K pages - see jfs_write.c
241 	 */
242 	BUG();
243 #endif				/* _JFS_4K */
244 
245       unlock:
246 	/*
247 	 * Release lock on inode
248 	 */
249 	if (create)
250 		IWRITE_UNLOCK(ip);
251 	else
252 		IREAD_UNLOCK(ip);
253 	return rc;
254 }
255 
256 static int jfs_writepage(struct page *page, struct writeback_control *wbc)
257 {
258 	return nobh_writepage(page, jfs_get_block, wbc);
259 }
260 
261 static int jfs_writepages(struct address_space *mapping,
262 			struct writeback_control *wbc)
263 {
264 	return mpage_writepages(mapping, wbc, jfs_get_block);
265 }
266 
267 static int jfs_readpage(struct file *file, struct page *page)
268 {
269 	return mpage_readpage(page, jfs_get_block);
270 }
271 
272 static int jfs_readpages(struct file *file, struct address_space *mapping,
273 		struct list_head *pages, unsigned nr_pages)
274 {
275 	return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
276 }
277 
278 static int jfs_prepare_write(struct file *file,
279 			     struct page *page, unsigned from, unsigned to)
280 {
281 	return nobh_prepare_write(page, from, to, jfs_get_block);
282 }
283 
284 static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
285 {
286 	return generic_block_bmap(mapping, block, jfs_get_block);
287 }
288 
289 static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
290 	const struct iovec *iov, loff_t offset, unsigned long nr_segs)
291 {
292 	struct file *file = iocb->ki_filp;
293 	struct inode *inode = file->f_mapping->host;
294 
295 	return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
296 				offset, nr_segs, jfs_get_block, NULL);
297 }
298 
299 const struct address_space_operations jfs_aops = {
300 	.readpage	= jfs_readpage,
301 	.readpages	= jfs_readpages,
302 	.writepage	= jfs_writepage,
303 	.writepages	= jfs_writepages,
304 	.sync_page	= block_sync_page,
305 	.prepare_write	= jfs_prepare_write,
306 	.commit_write	= nobh_commit_write,
307 	.bmap		= jfs_bmap,
308 	.direct_IO	= jfs_direct_IO,
309 };
310 
311 /*
312  * Guts of jfs_truncate.  Called with locks already held.  Can be called
313  * with directory for truncating directory index table.
314  */
315 void jfs_truncate_nolock(struct inode *ip, loff_t length)
316 {
317 	loff_t newsize;
318 	tid_t tid;
319 
320 	ASSERT(length >= 0);
321 
322 	if (test_cflag(COMMIT_Nolink, ip)) {
323 		xtTruncate(0, ip, length, COMMIT_WMAP);
324 		return;
325 	}
326 
327 	do {
328 		tid = txBegin(ip->i_sb, 0);
329 
330 		/*
331 		 * The commit_mutex cannot be taken before txBegin.
332 		 * txBegin may block and there is a chance the inode
333 		 * could be marked dirty and need to be committed
334 		 * before txBegin unblocks
335 		 */
336 		mutex_lock(&JFS_IP(ip)->commit_mutex);
337 
338 		newsize = xtTruncate(tid, ip, length,
339 				     COMMIT_TRUNCATE | COMMIT_PWMAP);
340 		if (newsize < 0) {
341 			txEnd(tid);
342 			mutex_unlock(&JFS_IP(ip)->commit_mutex);
343 			break;
344 		}
345 
346 		ip->i_mtime = ip->i_ctime = CURRENT_TIME;
347 		mark_inode_dirty(ip);
348 
349 		txCommit(tid, 1, &ip, 0);
350 		txEnd(tid);
351 		mutex_unlock(&JFS_IP(ip)->commit_mutex);
352 	} while (newsize > length);	/* Truncate isn't always atomic */
353 }
354 
355 void jfs_truncate(struct inode *ip)
356 {
357 	jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
358 
359 	nobh_truncate_page(ip->i_mapping, ip->i_size);
360 
361 	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
362 	jfs_truncate_nolock(ip, ip->i_size);
363 	IWRITE_UNLOCK(ip);
364 }
365