xref: /linux/fs/jfs/inode.c (revision 60b2737de1b1ddfdb90f3ba622634eb49d6f3603)
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 	down(&JFS_IP(inode)->commit_sem);
93 
94 	/*
95 	 * Retest inode state after taking commit_sem
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 	up(&JFS_IP(inode)->commit_sem);
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 (test_cflag(COMMIT_Freewmap, inode))
132 		jfs_free_zero_link(inode);
133 
134 	diFree(inode);
135 
136 	/*
137 	 * Free the inode from the quota allocation.
138 	 */
139 	DQUOT_INIT(inode);
140 	DQUOT_FREE_INODE(inode);
141 	DQUOT_DROP(inode);
142 
143 	clear_inode(inode);
144 }
145 
146 void jfs_dirty_inode(struct inode *inode)
147 {
148 	static int noisy = 5;
149 
150 	if (isReadOnly(inode)) {
151 		if (!special_file(inode->i_mode) && noisy) {
152 			/* kernel allows writes to devices on read-only
153 			 * partitions and may try to mark inode dirty
154 			 */
155 			jfs_err("jfs_dirty_inode called on read-only volume");
156 			jfs_err("Is remount racy?");
157 			noisy--;
158 		}
159 		return;
160 	}
161 
162 	set_cflag(COMMIT_Dirty, inode);
163 }
164 
165 static int
166 jfs_get_blocks(struct inode *ip, sector_t lblock, unsigned long max_blocks,
167 			struct buffer_head *bh_result, int create)
168 {
169 	s64 lblock64 = lblock;
170 	int rc = 0;
171 	xad_t xad;
172 	s64 xaddr;
173 	int xflag;
174 	s32 xlen = max_blocks;
175 
176 	/*
177 	 * Take appropriate lock on inode
178 	 */
179 	if (create)
180 		IWRITE_LOCK(ip);
181 	else
182 		IREAD_LOCK(ip);
183 
184 	if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
185 	    (!xtLookup(ip, lblock64, max_blocks, &xflag, &xaddr, &xlen, 0)) &&
186 	    xaddr) {
187 		if (xflag & XAD_NOTRECORDED) {
188 			if (!create)
189 				/*
190 				 * Allocated but not recorded, read treats
191 				 * this as a hole
192 				 */
193 				goto unlock;
194 #ifdef _JFS_4K
195 			XADoffset(&xad, lblock64);
196 			XADlength(&xad, xlen);
197 			XADaddress(&xad, xaddr);
198 #else				/* _JFS_4K */
199 			/*
200 			 * As long as block size = 4K, this isn't a problem.
201 			 * We should mark the whole page not ABNR, but how
202 			 * will we know to mark the other blocks BH_New?
203 			 */
204 			BUG();
205 #endif				/* _JFS_4K */
206 			rc = extRecord(ip, &xad);
207 			if (rc)
208 				goto unlock;
209 			set_buffer_new(bh_result);
210 		}
211 
212 		map_bh(bh_result, ip->i_sb, xaddr);
213 		bh_result->b_size = xlen << ip->i_blkbits;
214 		goto unlock;
215 	}
216 	if (!create)
217 		goto unlock;
218 
219 	/*
220 	 * Allocate a new block
221 	 */
222 #ifdef _JFS_4K
223 	if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
224 		goto unlock;
225 	rc = extAlloc(ip, xlen, lblock64, &xad, FALSE);
226 	if (rc)
227 		goto unlock;
228 
229 	set_buffer_new(bh_result);
230 	map_bh(bh_result, ip->i_sb, addressXAD(&xad));
231 	bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
232 
233 #else				/* _JFS_4K */
234 	/*
235 	 * We need to do whatever it takes to keep all but the last buffers
236 	 * in 4K pages - see jfs_write.c
237 	 */
238 	BUG();
239 #endif				/* _JFS_4K */
240 
241       unlock:
242 	/*
243 	 * Release lock on inode
244 	 */
245 	if (create)
246 		IWRITE_UNLOCK(ip);
247 	else
248 		IREAD_UNLOCK(ip);
249 	return rc;
250 }
251 
252 static int jfs_get_block(struct inode *ip, sector_t lblock,
253 			 struct buffer_head *bh_result, int create)
254 {
255 	return jfs_get_blocks(ip, lblock, 1, bh_result, create);
256 }
257 
258 static int jfs_writepage(struct page *page, struct writeback_control *wbc)
259 {
260 	return nobh_writepage(page, jfs_get_block, wbc);
261 }
262 
263 static int jfs_writepages(struct address_space *mapping,
264 			struct writeback_control *wbc)
265 {
266 	return mpage_writepages(mapping, wbc, jfs_get_block);
267 }
268 
269 static int jfs_readpage(struct file *file, struct page *page)
270 {
271 	return mpage_readpage(page, jfs_get_block);
272 }
273 
274 static int jfs_readpages(struct file *file, struct address_space *mapping,
275 		struct list_head *pages, unsigned nr_pages)
276 {
277 	return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
278 }
279 
280 static int jfs_prepare_write(struct file *file,
281 			     struct page *page, unsigned from, unsigned to)
282 {
283 	return nobh_prepare_write(page, from, to, jfs_get_block);
284 }
285 
286 static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
287 {
288 	return generic_block_bmap(mapping, block, jfs_get_block);
289 }
290 
291 static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
292 	const struct iovec *iov, loff_t offset, unsigned long nr_segs)
293 {
294 	struct file *file = iocb->ki_filp;
295 	struct inode *inode = file->f_mapping->host;
296 
297 	return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
298 				offset, nr_segs, jfs_get_blocks, NULL);
299 }
300 
301 struct address_space_operations jfs_aops = {
302 	.readpage	= jfs_readpage,
303 	.readpages	= jfs_readpages,
304 	.writepage	= jfs_writepage,
305 	.writepages	= jfs_writepages,
306 	.sync_page	= block_sync_page,
307 	.prepare_write	= jfs_prepare_write,
308 	.commit_write	= nobh_commit_write,
309 	.bmap		= jfs_bmap,
310 	.direct_IO	= jfs_direct_IO,
311 };
312 
313 /*
314  * Guts of jfs_truncate.  Called with locks already held.  Can be called
315  * with directory for truncating directory index table.
316  */
317 void jfs_truncate_nolock(struct inode *ip, loff_t length)
318 {
319 	loff_t newsize;
320 	tid_t tid;
321 
322 	ASSERT(length >= 0);
323 
324 	if (test_cflag(COMMIT_Nolink, ip)) {
325 		xtTruncate(0, ip, length, COMMIT_WMAP);
326 		return;
327 	}
328 
329 	do {
330 		tid = txBegin(ip->i_sb, 0);
331 
332 		/*
333 		 * The commit_sem cannot be taken before txBegin.
334 		 * txBegin may block and there is a chance the inode
335 		 * could be marked dirty and need to be committed
336 		 * before txBegin unblocks
337 		 */
338 		down(&JFS_IP(ip)->commit_sem);
339 
340 		newsize = xtTruncate(tid, ip, length,
341 				     COMMIT_TRUNCATE | COMMIT_PWMAP);
342 		if (newsize < 0) {
343 			txEnd(tid);
344 			up(&JFS_IP(ip)->commit_sem);
345 			break;
346 		}
347 
348 		ip->i_mtime = ip->i_ctime = CURRENT_TIME;
349 		mark_inode_dirty(ip);
350 
351 		txCommit(tid, 1, &ip, 0);
352 		txEnd(tid);
353 		up(&JFS_IP(ip)->commit_sem);
354 	} while (newsize > length);	/* Truncate isn't always atomic */
355 }
356 
357 void jfs_truncate(struct inode *ip)
358 {
359 	jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
360 
361 	nobh_truncate_page(ip->i_mapping, ip->i_size);
362 
363 	IWRITE_LOCK(ip);
364 	jfs_truncate_nolock(ip, ip->i_size);
365 	IWRITE_UNLOCK(ip);
366 }
367