xref: /openbmc/linux/fs/jfs/inode.c (revision f15cbe6f1a4b4d9df59142fc8e4abb973302cf44)
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 struct inode *jfs_iget(struct super_block *sb, unsigned long ino)
35 {
36 	struct inode *inode;
37 	int ret;
38 
39 	inode = iget_locked(sb, ino);
40 	if (!inode)
41 		return ERR_PTR(-ENOMEM);
42 	if (!(inode->i_state & I_NEW))
43 		return inode;
44 
45 	ret = diRead(inode);
46 	if (ret < 0) {
47 		iget_failed(inode);
48 		return ERR_PTR(ret);
49 	}
50 
51 	if (S_ISREG(inode->i_mode)) {
52 		inode->i_op = &jfs_file_inode_operations;
53 		inode->i_fop = &jfs_file_operations;
54 		inode->i_mapping->a_ops = &jfs_aops;
55 	} else if (S_ISDIR(inode->i_mode)) {
56 		inode->i_op = &jfs_dir_inode_operations;
57 		inode->i_fop = &jfs_dir_operations;
58 	} else if (S_ISLNK(inode->i_mode)) {
59 		if (inode->i_size >= IDATASIZE) {
60 			inode->i_op = &page_symlink_inode_operations;
61 			inode->i_mapping->a_ops = &jfs_aops;
62 		} else
63 			inode->i_op = &jfs_symlink_inode_operations;
64 	} else {
65 		inode->i_op = &jfs_file_inode_operations;
66 		init_special_inode(inode, inode->i_mode, inode->i_rdev);
67 	}
68 	unlock_new_inode(inode);
69 	return inode;
70 }
71 
72 /*
73  * Workhorse of both fsync & write_inode
74  */
75 int jfs_commit_inode(struct inode *inode, int wait)
76 {
77 	int rc = 0;
78 	tid_t tid;
79 	static int noisy = 5;
80 
81 	jfs_info("In jfs_commit_inode, inode = 0x%p", inode);
82 
83 	/*
84 	 * Don't commit if inode has been committed since last being
85 	 * marked dirty, or if it has been deleted.
86 	 */
87 	if (inode->i_nlink == 0 || !test_cflag(COMMIT_Dirty, inode))
88 		return 0;
89 
90 	if (isReadOnly(inode)) {
91 		/* kernel allows writes to devices on read-only
92 		 * partitions and may think inode is dirty
93 		 */
94 		if (!special_file(inode->i_mode) && noisy) {
95 			jfs_err("jfs_commit_inode(0x%p) called on "
96 				   "read-only volume", inode);
97 			jfs_err("Is remount racy?");
98 			noisy--;
99 		}
100 		return 0;
101 	}
102 
103 	tid = txBegin(inode->i_sb, COMMIT_INODE);
104 	mutex_lock(&JFS_IP(inode)->commit_mutex);
105 
106 	/*
107 	 * Retest inode state after taking commit_mutex
108 	 */
109 	if (inode->i_nlink && test_cflag(COMMIT_Dirty, inode))
110 		rc = txCommit(tid, 1, &inode, wait ? COMMIT_SYNC : 0);
111 
112 	txEnd(tid);
113 	mutex_unlock(&JFS_IP(inode)->commit_mutex);
114 	return rc;
115 }
116 
117 int jfs_write_inode(struct inode *inode, int wait)
118 {
119 	if (test_cflag(COMMIT_Nolink, inode))
120 		return 0;
121 	/*
122 	 * If COMMIT_DIRTY is not set, the inode isn't really dirty.
123 	 * It has been committed since the last change, but was still
124 	 * on the dirty inode list.
125 	 */
126 	 if (!test_cflag(COMMIT_Dirty, inode)) {
127 		/* Make sure committed changes hit the disk */
128 		jfs_flush_journal(JFS_SBI(inode->i_sb)->log, wait);
129 		return 0;
130 	 }
131 
132 	if (jfs_commit_inode(inode, wait)) {
133 		jfs_err("jfs_write_inode: jfs_commit_inode failed!");
134 		return -EIO;
135 	} else
136 		return 0;
137 }
138 
139 void jfs_delete_inode(struct inode *inode)
140 {
141 	jfs_info("In jfs_delete_inode, inode = 0x%p", inode);
142 
143 	if (!is_bad_inode(inode) &&
144 	    (JFS_IP(inode)->fileset == FILESYSTEM_I)) {
145 		truncate_inode_pages(&inode->i_data, 0);
146 
147 		if (test_cflag(COMMIT_Freewmap, inode))
148 			jfs_free_zero_link(inode);
149 
150 		diFree(inode);
151 
152 		/*
153 		 * Free the inode from the quota allocation.
154 		 */
155 		DQUOT_INIT(inode);
156 		DQUOT_FREE_INODE(inode);
157 		DQUOT_DROP(inode);
158 	}
159 
160 	clear_inode(inode);
161 }
162 
163 void jfs_dirty_inode(struct inode *inode)
164 {
165 	static int noisy = 5;
166 
167 	if (isReadOnly(inode)) {
168 		if (!special_file(inode->i_mode) && noisy) {
169 			/* kernel allows writes to devices on read-only
170 			 * partitions and may try to mark inode dirty
171 			 */
172 			jfs_err("jfs_dirty_inode called on read-only volume");
173 			jfs_err("Is remount racy?");
174 			noisy--;
175 		}
176 		return;
177 	}
178 
179 	set_cflag(COMMIT_Dirty, inode);
180 }
181 
182 int jfs_get_block(struct inode *ip, sector_t lblock,
183 		  struct buffer_head *bh_result, int create)
184 {
185 	s64 lblock64 = lblock;
186 	int rc = 0;
187 	xad_t xad;
188 	s64 xaddr;
189 	int xflag;
190 	s32 xlen = bh_result->b_size >> ip->i_blkbits;
191 
192 	/*
193 	 * Take appropriate lock on inode
194 	 */
195 	if (create)
196 		IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
197 	else
198 		IREAD_LOCK(ip, RDWRLOCK_NORMAL);
199 
200 	if (((lblock64 << ip->i_sb->s_blocksize_bits) < ip->i_size) &&
201 	    (!xtLookup(ip, lblock64, xlen, &xflag, &xaddr, &xlen, 0)) &&
202 	    xaddr) {
203 		if (xflag & XAD_NOTRECORDED) {
204 			if (!create)
205 				/*
206 				 * Allocated but not recorded, read treats
207 				 * this as a hole
208 				 */
209 				goto unlock;
210 #ifdef _JFS_4K
211 			XADoffset(&xad, lblock64);
212 			XADlength(&xad, xlen);
213 			XADaddress(&xad, xaddr);
214 #else				/* _JFS_4K */
215 			/*
216 			 * As long as block size = 4K, this isn't a problem.
217 			 * We should mark the whole page not ABNR, but how
218 			 * will we know to mark the other blocks BH_New?
219 			 */
220 			BUG();
221 #endif				/* _JFS_4K */
222 			rc = extRecord(ip, &xad);
223 			if (rc)
224 				goto unlock;
225 			set_buffer_new(bh_result);
226 		}
227 
228 		map_bh(bh_result, ip->i_sb, xaddr);
229 		bh_result->b_size = xlen << ip->i_blkbits;
230 		goto unlock;
231 	}
232 	if (!create)
233 		goto unlock;
234 
235 	/*
236 	 * Allocate a new block
237 	 */
238 #ifdef _JFS_4K
239 	if ((rc = extHint(ip, lblock64 << ip->i_sb->s_blocksize_bits, &xad)))
240 		goto unlock;
241 	rc = extAlloc(ip, xlen, lblock64, &xad, false);
242 	if (rc)
243 		goto unlock;
244 
245 	set_buffer_new(bh_result);
246 	map_bh(bh_result, ip->i_sb, addressXAD(&xad));
247 	bh_result->b_size = lengthXAD(&xad) << ip->i_blkbits;
248 
249 #else				/* _JFS_4K */
250 	/*
251 	 * We need to do whatever it takes to keep all but the last buffers
252 	 * in 4K pages - see jfs_write.c
253 	 */
254 	BUG();
255 #endif				/* _JFS_4K */
256 
257       unlock:
258 	/*
259 	 * Release lock on inode
260 	 */
261 	if (create)
262 		IWRITE_UNLOCK(ip);
263 	else
264 		IREAD_UNLOCK(ip);
265 	return rc;
266 }
267 
268 static int jfs_writepage(struct page *page, struct writeback_control *wbc)
269 {
270 	return block_write_full_page(page, jfs_get_block, wbc);
271 }
272 
273 static int jfs_writepages(struct address_space *mapping,
274 			struct writeback_control *wbc)
275 {
276 	return mpage_writepages(mapping, wbc, jfs_get_block);
277 }
278 
279 static int jfs_readpage(struct file *file, struct page *page)
280 {
281 	return mpage_readpage(page, jfs_get_block);
282 }
283 
284 static int jfs_readpages(struct file *file, struct address_space *mapping,
285 		struct list_head *pages, unsigned nr_pages)
286 {
287 	return mpage_readpages(mapping, pages, nr_pages, jfs_get_block);
288 }
289 
290 static int jfs_write_begin(struct file *file, struct address_space *mapping,
291 				loff_t pos, unsigned len, unsigned flags,
292 				struct page **pagep, void **fsdata)
293 {
294 	return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
295 				jfs_get_block);
296 }
297 
298 static sector_t jfs_bmap(struct address_space *mapping, sector_t block)
299 {
300 	return generic_block_bmap(mapping, block, jfs_get_block);
301 }
302 
303 static ssize_t jfs_direct_IO(int rw, struct kiocb *iocb,
304 	const struct iovec *iov, loff_t offset, unsigned long nr_segs)
305 {
306 	struct file *file = iocb->ki_filp;
307 	struct inode *inode = file->f_mapping->host;
308 
309 	return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
310 				offset, nr_segs, jfs_get_block, NULL);
311 }
312 
313 const struct address_space_operations jfs_aops = {
314 	.readpage	= jfs_readpage,
315 	.readpages	= jfs_readpages,
316 	.writepage	= jfs_writepage,
317 	.writepages	= jfs_writepages,
318 	.sync_page	= block_sync_page,
319 	.write_begin	= jfs_write_begin,
320 	.write_end	= nobh_write_end,
321 	.bmap		= jfs_bmap,
322 	.direct_IO	= jfs_direct_IO,
323 };
324 
325 /*
326  * Guts of jfs_truncate.  Called with locks already held.  Can be called
327  * with directory for truncating directory index table.
328  */
329 void jfs_truncate_nolock(struct inode *ip, loff_t length)
330 {
331 	loff_t newsize;
332 	tid_t tid;
333 
334 	ASSERT(length >= 0);
335 
336 	if (test_cflag(COMMIT_Nolink, ip)) {
337 		xtTruncate(0, ip, length, COMMIT_WMAP);
338 		return;
339 	}
340 
341 	do {
342 		tid = txBegin(ip->i_sb, 0);
343 
344 		/*
345 		 * The commit_mutex cannot be taken before txBegin.
346 		 * txBegin may block and there is a chance the inode
347 		 * could be marked dirty and need to be committed
348 		 * before txBegin unblocks
349 		 */
350 		mutex_lock(&JFS_IP(ip)->commit_mutex);
351 
352 		newsize = xtTruncate(tid, ip, length,
353 				     COMMIT_TRUNCATE | COMMIT_PWMAP);
354 		if (newsize < 0) {
355 			txEnd(tid);
356 			mutex_unlock(&JFS_IP(ip)->commit_mutex);
357 			break;
358 		}
359 
360 		ip->i_mtime = ip->i_ctime = CURRENT_TIME;
361 		mark_inode_dirty(ip);
362 
363 		txCommit(tid, 1, &ip, 0);
364 		txEnd(tid);
365 		mutex_unlock(&JFS_IP(ip)->commit_mutex);
366 	} while (newsize > length);	/* Truncate isn't always atomic */
367 }
368 
369 void jfs_truncate(struct inode *ip)
370 {
371 	jfs_info("jfs_truncate: size = 0x%lx", (ulong) ip->i_size);
372 
373 	nobh_truncate_page(ip->i_mapping, ip->i_size, jfs_get_block);
374 
375 	IWRITE_LOCK(ip, RDWRLOCK_NORMAL);
376 	jfs_truncate_nolock(ip, ip->i_size);
377 	IWRITE_UNLOCK(ip);
378 }
379