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  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
 44struct kmem_cache		*vxfs_inode_cachep;
 45
 46
 47#ifdef DIAGNOSTIC
 48/*
 49 * Dump inode contents (partially).
 50 */
 51void
 52vxfs_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 */
 87struct vxfs_inode_info *
 88vxfs_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
112fail:
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 */
129static 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
157fail:
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 */
173struct vxfs_inode_info *
174vxfs_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 */
190static __inline__ umode_t
191vxfs_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 */
222static void
223vxfs_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 */
257struct inode *
258vxfs_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 */
277void
278vxfs_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 */
292struct inode *
293vxfs_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
340static 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 */
354void
355vxfs_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}