xref: /linux/fs/jfs/inode.c (revision 14b42963f64b98ab61fa9723c03d71aa5ef4f862)
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 	jfs_set_inode_flags(inode);
59 }
60 
61 /*
62  * Workhorse of both fsync & write_inode
63  */
64 int jfs_commit_inode(struct inode *inode, int wait)
65 {
66 	int rc = 0;
67 	tid_t tid;
68 	static int noisy = 5;
69 
70 	jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
71 
72 	/*
73 	 * Don't commit if inode has been committed since last being
74 	 * marked dirty, or if it has been deleted.
75 	 */
76 	if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
77 		return 0;
78 
79 	if (isReadOnly(inode)) {
80 		/* kernel allows writes to devices on read-only
81 		 * partitions and may think inode is dirty
82 		 */
83 		if (!special_file(inode->i_mode) && noisy) {
84 			jfs_err("jfs_commit_inode(0x%p) called on "
85 				   "read-only volume", inode);
86 			jfs_err("Is remount racy?");
87 			noisy--;
88 		}
89 		return 0;
90 	}
91 
92 	tid = txBegin(inode->i_sb, COMMIT_INODE);
93 	mutex_lock(&JFS_IP(inode)->commit_mutex);
94 
95 	/*
96 	 * Retest inode state after taking commit_mutex
97 	 */
98 	if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
99 		rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
100 
101 	txEnd(tid);
102 	mutex_unlock(&JFS_IP(inode)->commit_mutex);
103 	return rc;
104 }
105 
106 int jfs_write_inode(struct inode *inode, int wait)
107 {
108 	if (test_cflag(COMMIT_Nolink, inode))
109 		return 0;
110 	/*
111 	 * If COMMIT_DIRTY is not set, the inode isn't really dirty.
112 	 * It has been committed since the last change, but was still
113 	 * on the dirty inode list.
114 	 */
115 	 if (!test_cflag(COMMIT_Dirty, inode)) {
116 		/* Make sure committed changes hit the disk */
117 		jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
118 		return 0;
119 	 }
120 
121 	if (jfs_commit_inode(inode, wait)) {
122 		jfs_err("jfs_write_inode: jfs_commit_inode failed!");
123 		return -EIO;
124 	} else
125 		return 0;
126 }
127 
128 void jfs_delete_inode(struct inode *inode)
129 {
130 	jfs_info("In jfs_delete_inode, inode = 0x%p", inode);
131 
132 	if (!is_bad_inode(inode) &&
133 	    (JFS_IP(inode)->fileset == FILESYSTEM_I)) {
134 		truncate_inode_pages(&inode->i_data, 0);
135 
136 		if (test_cflag(COMMIT_Freewmap, inode))
137 			jfs_free_zero_link(inode);
138 
139 		diFree(inode);
140 
141 		/*
142 		 * Free the inode from the quota allocation.
143 		 */
144 		DQUOT_INIT(inode);
145 		DQUOT_FREE_INODE(inode);
146 		DQUOT_DROP(inode);
147 	}
148 
149 	clear_inode(inode);
150 }
151 
152 void jfs_dirty_inode(struct inode *inode)
153 {
154 	static int noisy = 5;
155 
156 	if (isReadOnly(inode)) {
157 		if (!special_file(inode->i_mode) && noisy) {
158 			/* kernel allows writes to devices on read-only
159 			 * partitions and may try to mark inode dirty
160 			 */
161 			jfs_err("jfs_dirty_inode called on read-only volume");
162 			jfs_err("Is remount racy?");
163 			noisy--;
164 		}
165 		return;
166 	}
167 
168 	set_cflag(COMMIT_Dirty, inode);
169 }
170 
171 static int
172 jfs_get_blocks(struct inode *ip, sector_t lblock, unsigned long max_blocks,
173 			struct buffer_head *bh_result, int create)
174 {
175 	s64 lblock64 = lblock;
176 	int rc = 0;
177 	xad_t xad;
178 	s64 xaddr;
179 	int xflag;
180 	s32 xlen = max_blocks;
181 
182 	/*
183 	 * Take appropriate lock on inode
184 	 */
185 	if (create)
186 		IWRITE_LOCK(ip);
187 	else
188 		IREAD_LOCK(ip);
189 
190 	if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
191 	    (!xtLookup(ip, lblock64, max_blocks, &xflag, &xaddr, &xlen, 0)) &&
192 	    xaddr) {
193 		if (xflag & XAD_NOTRECORDED) {
194 			if (!create)
195 				/*
196 				 * Allocated but not recorded, read treats
197 				 * this as a hole
198 				 */
199 				goto unlock;
200 #ifdef _JFS_4K
201 			XADoffset(&xad, lblock64);
202 			XADlength(&xad, xlen);
203 			XADaddress(&xad, xaddr);
204 #else				/* _JFS_4K */
205 			/*
206 			 * As long as block size = 4K, this isn't a problem.
207 			 * We should mark the whole page not ABNR, but how
208 			 * will we know to mark the other blocks BH_New?
209 			 */
210 			BUG();
211 #endif				/* _JFS_4K */
212 			rc = extRecord(ip, &xad);
213 			if (rc)
214 				goto unlock;
215 			set_buffer_new(bh_result);
216 		}
217 
218 		map_bh(bh_result, ip->i_sb, xaddr);
219 		bh_result->b_size = xlen << ip->i_blkbits;
220 		goto unlock;
221 	}
222 	if (!create)
223 		goto unlock;
224 
225 	/*
226 	 * Allocate a new block
227 	 */
228 #ifdef _JFS_4K
229 	if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
230 		goto unlock;
231 	rc = extAlloc(ip, xlen, lblock64, &xad, FALSE);
232 	if (rc)
233 		goto unlock;
234 
235 	set_buffer_new(bh_result);
236 	map_bh(bh_result, ip->i_sb, addressXAD(&xad));
237 	bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
238 
239 #else				/* _JFS_4K */
240 	/*
241 	 * We need to do whatever it takes to keep all but the last buffers
242 	 * in 4K pages - see jfs_write.c
243 	 */
244 	BUG();
245 #endif				/* _JFS_4K */
246 
247       unlock:
248 	/*
249 	 * Release lock on inode
250 	 */
251 	if (create)
252 		IWRITE_UNLOCK(ip);
253 	else
254 		IREAD_UNLOCK(ip);
255 	return rc;
256 }
257 
258 static int jfs_get_block(struct inode *ip, sector_t lblock,
259 			 struct buffer_head *bh_result, int create)
260 {
261 	return jfs_get_blocks(ip, lblock, bh_result->b_size >> ip->i_blkbits,
262 			bh_result, create);
263 }
264 
265 static int jfs_writepage(struct page *page, struct writeback_control *wbc)
266 {
267 	return nobh_writepage(page, jfs_get_block, wbc);
268 }
269 
270 static int jfs_writepages(struct address_space *mapping,
271 			struct writeback_control *wbc)
272 {
273 	return mpage_writepages(mapping, wbc, jfs_get_block);
274 }
275 
276 static int jfs_readpage(struct file *file, struct page *page)
277 {
278 	return mpage_readpage(page, jfs_get_block);
279 }
280 
281 static int jfs_readpages(struct file *file, struct address_space *mapping,
282 		struct list_head *pages, unsigned nr_pages)
283 {
284 	return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
285 }
286 
287 static int jfs_prepare_write(struct file *file,
288 			     struct page *page, unsigned from, unsigned to)
289 {
290 	return nobh_prepare_write(page, from, to, jfs_get_block);
291 }
292 
293 static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
294 {
295 	return generic_block_bmap(mapping, block, jfs_get_block);
296 }
297 
298 static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
299 	const struct iovec *iov, loff_t offset, unsigned long nr_segs)
300 {
301 	struct file *file = iocb->ki_filp;
302 	struct inode *inode = file->f_mapping->host;
303 
304 	return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
305 				offset, nr_segs, jfs_get_block, NULL);
306 }
307 
308 const struct address_space_operations jfs_aops = {
309 	.readpage	= jfs_readpage,
310 	.readpages	= jfs_readpages,
311 	.writepage	= jfs_writepage,
312 	.writepages	= jfs_writepages,
313 	.sync_page	= block_sync_page,
314 	.prepare_write	= jfs_prepare_write,
315 	.commit_write	= nobh_commit_write,
316 	.bmap		= jfs_bmap,
317 	.direct_IO	= jfs_direct_IO,
318 };
319 
320 /*
321  * Guts of jfs_truncate.  Called with locks already held.  Can be called
322  * with directory for truncating directory index table.
323  */
324 void jfs_truncate_nolock(struct inode *ip, loff_t length)
325 {
326 	loff_t newsize;
327 	tid_t tid;
328 
329 	ASSERT(length >= 0);
330 
331 	if (test_cflag(COMMIT_Nolink, ip)) {
332 		xtTruncate(0, ip, length, COMMIT_WMAP);
333 		return;
334 	}
335 
336 	do {
337 		tid = txBegin(ip->i_sb, 0);
338 
339 		/*
340 		 * The commit_mutex cannot be taken before txBegin.
341 		 * txBegin may block and there is a chance the inode
342 		 * could be marked dirty and need to be committed
343 		 * before txBegin unblocks
344 		 */
345 		mutex_lock(&JFS_IP(ip)->commit_mutex);
346 
347 		newsize = xtTruncate(tid, ip, length,
348 				     COMMIT_TRUNCATE | COMMIT_PWMAP);
349 		if (newsize < 0) {
350 			txEnd(tid);
351 			mutex_unlock(&JFS_IP(ip)->commit_mutex);
352 			break;
353 		}
354 
355 		ip->i_mtime = ip->i_ctime = CURRENT_TIME;
356 		mark_inode_dirty(ip);
357 
358 		txCommit(tid, 1, &ip, 0);
359 		txEnd(tid);
360 		mutex_unlock(&JFS_IP(ip)->commit_mutex);
361 	} while (newsize > length);	/* Truncate isn't always atomic */
362 }
363 
364 void jfs_truncate(struct inode *ip)
365 {
366 	jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
367 
368 	nobh_truncate_page(ip->i_mapping, ip->i_size);
369 
370 	IWRITE_LOCK(ip);
371 	jfs_truncate_nolock(ip, ip->i_size);
372 	IWRITE_UNLOCK(ip);
373 }
374