xref: /openbmc/linux/fs/freevxfs/vxfs_inode.c (revision 95e9fd10)
1 /*
2  * Copyright (c) 2000-2001 Christoph Hellwig.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions, and the following disclaimer,
10  *    without modification.
11  * 2. The name of the author may not be used to endorse or promote products
12  *    derived from this software without specific prior written permission.
13  *
14  * Alternatively, this software may be distributed under the terms of the
15  * GNU General Public License ("GPL").
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21  * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 /*
31  * Veritas filesystem driver - inode routines.
32  */
33 #include <linux/fs.h>
34 #include <linux/buffer_head.h>
35 #include <linux/pagemap.h>
36 #include <linux/kernel.h>
37 #include <linux/slab.h>
38 
39 #include "vxfs.h"
40 #include "vxfs_inode.h"
41 #include "vxfs_extern.h"
42 
43 
44 struct kmem_cache		*vxfs_inode_cachep;
45 
46 
47 #ifdef DIAGNOSTIC
48 /*
49  * Dump inode contents (partially).
50  */
51 void
52 vxfs_dumpi(struct vxfs_inode_info *vip, ino_t ino)
53 {
54 	printk(KERN_DEBUG "\n\n");
55 	if (ino)
56 		printk(KERN_DEBUG "dumping vxfs inode %ld\n", ino);
57 	else
58 		printk(KERN_DEBUG "dumping unknown vxfs inode\n");
59 
60 	printk(KERN_DEBUG "---------------------------\n");
61 	printk(KERN_DEBUG "mode is %x\n", vip->vii_mode);
62 	printk(KERN_DEBUG "nlink:%u, uid:%u, gid:%u\n",
63 			vip->vii_nlink, vip->vii_uid, vip->vii_gid);
64 	printk(KERN_DEBUG "size:%Lx, blocks:%u\n",
65 			vip->vii_size, vip->vii_blocks);
66 	printk(KERN_DEBUG "orgtype:%u\n", vip->vii_orgtype);
67 }
68 #endif
69 
70 
71 /**
72  * vxfs_blkiget - find inode based on extent #
73  * @sbp:	superblock of the filesystem we search in
74  * @extent:	number of the extent to search
75  * @ino:	inode number to search
76  *
77  * Description:
78  *  vxfs_blkiget searches inode @ino in the filesystem described by
79  *  @sbp in the extent @extent.
80  *  Returns the matching VxFS inode on success, else a NULL pointer.
81  *
82  * NOTE:
83  *  While __vxfs_iget uses the pagecache vxfs_blkiget uses the
84  *  buffercache.  This function should not be used outside the
85  *  read_super() method, otherwise the data may be incoherent.
86  */
87 struct vxfs_inode_info *
88 vxfs_blkiget(struct super_block *sbp, u_long extent, ino_t ino)
89 {
90 	struct buffer_head		*bp;
91 	u_long				block, offset;
92 
93 	block = extent + ((ino * VXFS_ISIZE) / sbp->s_blocksize);
94 	offset = ((ino % (sbp->s_blocksize / VXFS_ISIZE)) * VXFS_ISIZE);
95 	bp = sb_bread(sbp, block);
96 
97 	if (bp && buffer_mapped(bp)) {
98 		struct vxfs_inode_info	*vip;
99 		struct vxfs_dinode	*dip;
100 
101 		if (!(vip = kmem_cache_alloc(vxfs_inode_cachep, GFP_KERNEL)))
102 			goto fail;
103 		dip = (struct vxfs_dinode *)(bp->b_data + offset);
104 		memcpy(vip, dip, sizeof(*vip));
105 #ifdef DIAGNOSTIC
106 		vxfs_dumpi(vip, ino);
107 #endif
108 		brelse(bp);
109 		return (vip);
110 	}
111 
112 fail:
113 	printk(KERN_WARNING "vxfs: unable to read block %ld\n", block);
114 	brelse(bp);
115 	return NULL;
116 }
117 
118 /**
119  * __vxfs_iget - generic find inode facility
120  * @sbp:		VFS superblock
121  * @ino:		inode number
122  * @ilistp:		inode list
123  *
124  * Description:
125  *  Search the for inode number @ino in the filesystem
126  *  described by @sbp.  Use the specified inode table (@ilistp).
127  *  Returns the matching VxFS inode on success, else an error code.
128  */
129 static struct vxfs_inode_info *
130 __vxfs_iget(ino_t ino, struct inode *ilistp)
131 {
132 	struct page			*pp;
133 	u_long				offset;
134 
135 	offset = (ino % (PAGE_SIZE / VXFS_ISIZE)) * VXFS_ISIZE;
136 	pp = vxfs_get_page(ilistp->i_mapping, ino * VXFS_ISIZE / PAGE_SIZE);
137 
138 	if (!IS_ERR(pp)) {
139 		struct vxfs_inode_info	*vip;
140 		struct vxfs_dinode	*dip;
141 		caddr_t			kaddr = (char *)page_address(pp);
142 
143 		if (!(vip = kmem_cache_alloc(vxfs_inode_cachep, GFP_KERNEL)))
144 			goto fail;
145 		dip = (struct vxfs_dinode *)(kaddr + offset);
146 		memcpy(vip, dip, sizeof(*vip));
147 #ifdef DIAGNOSTIC
148 		vxfs_dumpi(vip, ino);
149 #endif
150 		vxfs_put_page(pp);
151 		return (vip);
152 	}
153 
154 	printk(KERN_WARNING "vxfs: error on page %p\n", pp);
155 	return ERR_CAST(pp);
156 
157 fail:
158 	printk(KERN_WARNING "vxfs: unable to read inode %ld\n", (unsigned long)ino);
159 	vxfs_put_page(pp);
160 	return ERR_PTR(-ENOMEM);
161 }
162 
163 /**
164  * vxfs_stiget - find inode using the structural inode list
165  * @sbp:	VFS superblock
166  * @ino:	inode #
167  *
168  * Description:
169  *  Find inode @ino in the filesystem described by @sbp using
170  *  the structural inode list.
171  *  Returns the matching VxFS inode on success, else a NULL pointer.
172  */
173 struct vxfs_inode_info *
174 vxfs_stiget(struct super_block *sbp, ino_t ino)
175 {
176 	struct vxfs_inode_info *vip;
177 
178 	vip = __vxfs_iget(ino, VXFS_SBI(sbp)->vsi_stilist);
179 	return IS_ERR(vip) ? NULL : vip;
180 }
181 
182 /**
183  * vxfs_transmod - mode for a VxFS inode
184  * @vip:	VxFS inode
185  *
186  * Description:
187  *  vxfs_transmod returns a Linux mode_t for a given
188  *  VxFS inode structure.
189  */
190 static __inline__ umode_t
191 vxfs_transmod(struct vxfs_inode_info *vip)
192 {
193 	umode_t			ret = vip->vii_mode & ~VXFS_TYPE_MASK;
194 
195 	if (VXFS_ISFIFO(vip))
196 		ret |= S_IFIFO;
197 	if (VXFS_ISCHR(vip))
198 		ret |= S_IFCHR;
199 	if (VXFS_ISDIR(vip))
200 		ret |= S_IFDIR;
201 	if (VXFS_ISBLK(vip))
202 		ret |= S_IFBLK;
203 	if (VXFS_ISLNK(vip))
204 		ret |= S_IFLNK;
205 	if (VXFS_ISREG(vip))
206 		ret |= S_IFREG;
207 	if (VXFS_ISSOC(vip))
208 		ret |= S_IFSOCK;
209 
210 	return (ret);
211 }
212 
213 /**
214  * vxfs_iinit- helper to fill inode fields
215  * @ip:		VFS inode
216  * @vip:	VxFS inode
217  *
218  * Description:
219  *  vxfs_instino is a helper function to fill in all relevant
220  *  fields in @ip from @vip.
221  */
222 static void
223 vxfs_iinit(struct inode *ip, struct vxfs_inode_info *vip)
224 {
225 
226 	ip->i_mode = vxfs_transmod(vip);
227 	ip->i_uid = (uid_t)vip->vii_uid;
228 	ip->i_gid = (gid_t)vip->vii_gid;
229 
230 	set_nlink(ip, vip->vii_nlink);
231 	ip->i_size = vip->vii_size;
232 
233 	ip->i_atime.tv_sec = vip->vii_atime;
234 	ip->i_ctime.tv_sec = vip->vii_ctime;
235 	ip->i_mtime.tv_sec = vip->vii_mtime;
236 	ip->i_atime.tv_nsec = 0;
237 	ip->i_ctime.tv_nsec = 0;
238 	ip->i_mtime.tv_nsec = 0;
239 
240 	ip->i_blocks = vip->vii_blocks;
241 	ip->i_generation = vip->vii_gen;
242 
243 	ip->i_private = vip;
244 
245 }
246 
247 /**
248  * vxfs_get_fake_inode - get fake inode structure
249  * @sbp:		filesystem superblock
250  * @vip:		fspriv inode
251  *
252  * Description:
253  *  vxfs_fake_inode gets a fake inode (not in the inode hash) for a
254  *  superblock, vxfs_inode pair.
255  *  Returns the filled VFS inode.
256  */
257 struct inode *
258 vxfs_get_fake_inode(struct super_block *sbp, struct vxfs_inode_info *vip)
259 {
260 	struct inode			*ip = NULL;
261 
262 	if ((ip = new_inode(sbp))) {
263 		ip->i_ino = get_next_ino();
264 		vxfs_iinit(ip, vip);
265 		ip->i_mapping->a_ops = &vxfs_aops;
266 	}
267 	return (ip);
268 }
269 
270 /**
271  * vxfs_put_fake_inode - free faked inode
272  * *ip:			VFS inode
273  *
274  * Description:
275  *  vxfs_put_fake_inode frees all data associated with @ip.
276  */
277 void
278 vxfs_put_fake_inode(struct inode *ip)
279 {
280 	iput(ip);
281 }
282 
283 /**
284  * vxfs_iget - get an inode
285  * @sbp:	the superblock to get the inode for
286  * @ino:	the number of the inode to get
287  *
288  * Description:
289  *  vxfs_read_inode creates an inode, reads the disk inode for @ino and fills
290  *  in all relevant fields in the new inode.
291  */
292 struct inode *
293 vxfs_iget(struct super_block *sbp, ino_t ino)
294 {
295 	struct vxfs_inode_info		*vip;
296 	const struct address_space_operations	*aops;
297 	struct inode *ip;
298 
299 	ip = iget_locked(sbp, ino);
300 	if (!ip)
301 		return ERR_PTR(-ENOMEM);
302 	if (!(ip->i_state & I_NEW))
303 		return ip;
304 
305 	vip = __vxfs_iget(ino, VXFS_SBI(sbp)->vsi_ilist);
306 	if (IS_ERR(vip)) {
307 		iget_failed(ip);
308 		return ERR_CAST(vip);
309 	}
310 
311 	vxfs_iinit(ip, vip);
312 
313 	if (VXFS_ISIMMED(vip))
314 		aops = &vxfs_immed_aops;
315 	else
316 		aops = &vxfs_aops;
317 
318 	if (S_ISREG(ip->i_mode)) {
319 		ip->i_fop = &generic_ro_fops;
320 		ip->i_mapping->a_ops = aops;
321 	} else if (S_ISDIR(ip->i_mode)) {
322 		ip->i_op = &vxfs_dir_inode_ops;
323 		ip->i_fop = &vxfs_dir_operations;
324 		ip->i_mapping->a_ops = aops;
325 	} else if (S_ISLNK(ip->i_mode)) {
326 		if (!VXFS_ISIMMED(vip)) {
327 			ip->i_op = &page_symlink_inode_operations;
328 			ip->i_mapping->a_ops = &vxfs_aops;
329 		} else {
330 			ip->i_op = &vxfs_immed_symlink_iops;
331 			vip->vii_immed.vi_immed[ip->i_size] = '\0';
332 		}
333 	} else
334 		init_special_inode(ip, ip->i_mode, old_decode_dev(vip->vii_rdev));
335 
336 	unlock_new_inode(ip);
337 	return ip;
338 }
339 
340 static void vxfs_i_callback(struct rcu_head *head)
341 {
342 	struct inode *inode = container_of(head, struct inode, i_rcu);
343 	kmem_cache_free(vxfs_inode_cachep, inode->i_private);
344 }
345 
346 /**
347  * vxfs_evict_inode - remove inode from main memory
348  * @ip:		inode to discard.
349  *
350  * Description:
351  *  vxfs_evict_inode() is called on the final iput and frees the private
352  *  inode area.
353  */
354 void
355 vxfs_evict_inode(struct inode *ip)
356 {
357 	truncate_inode_pages(&ip->i_data, 0);
358 	clear_inode(ip);
359 	call_rcu(&ip->i_rcu, vxfs_i_callback);
360 }
361