vxfs_super.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (c) 2000-2001 Christoph Hellwig.
  4 * Copyright (c) 2016 Krzysztof Blaszkowski
  5 */
  6
  7/*
  8 * Veritas filesystem driver - superblock related routines.
  9 */
 10#include <linux/init.h>
 11#include <linux/module.h>
 12
 13#include <linux/blkdev.h>
 14#include <linux/fs.h>
 15#include <linux/buffer_head.h>
 16#include <linux/kernel.h>
 17#include <linux/slab.h>
 18#include <linux/stat.h>
 19#include <linux/vfs.h>
 20#include <linux/fs_context.h>
 21
 22#include "vxfs.h"
 23#include "vxfs_extern.h"
 24#include "vxfs_dir.h"
 25#include "vxfs_inode.h"
 26
 27
 28MODULE_AUTHOR("Christoph Hellwig, Krzysztof Blaszkowski");
 29MODULE_DESCRIPTION("Veritas Filesystem (VxFS) driver");
 30MODULE_LICENSE("Dual BSD/GPL");
 31
 32static struct kmem_cache *vxfs_inode_cachep;
 33
 34/**
 35 * vxfs_put_super - free superblock resources
 36 * @sbp:	VFS superblock.
 37 *
 38 * Description:
 39 *   vxfs_put_super frees all resources allocated for @sbp
 40 *   after the last instance of the filesystem is unmounted.
 41 */
 42
 43static void
 44vxfs_put_super(struct super_block *sbp)
 45{
 46	struct vxfs_sb_info	*infp = VXFS_SBI(sbp);
 47
 48	iput(infp->vsi_fship);
 49	iput(infp->vsi_ilist);
 50	iput(infp->vsi_stilist);
 51
 52	brelse(infp->vsi_bp);
 53	kfree(infp);
 54}
 55
 56/**
 57 * vxfs_statfs - get filesystem information
 58 * @dentry:	VFS dentry to locate superblock
 59 * @bufp:	output buffer
 60 *
 61 * Description:
 62 *   vxfs_statfs fills the statfs buffer @bufp with information
 63 *   about the filesystem described by @dentry.
 64 *
 65 * Returns:
 66 *   Zero.
 67 *
 68 * Locking:
 69 *   No locks held.
 70 *
 71 * Notes:
 72 *   This is everything but complete...
 73 */
 74static int
 75vxfs_statfs(struct dentry *dentry, struct kstatfs *bufp)
 76{
 77	struct vxfs_sb_info		*infp = VXFS_SBI(dentry->d_sb);
 78	struct vxfs_sb *raw_sb = infp->vsi_raw;
 79	u64 id = huge_encode_dev(dentry->d_sb->s_bdev->bd_dev);
 80
 81	bufp->f_type = VXFS_SUPER_MAGIC;
 82	bufp->f_bsize = dentry->d_sb->s_blocksize;
 83	bufp->f_blocks = fs32_to_cpu(infp, raw_sb->vs_dsize);
 84	bufp->f_bfree = fs32_to_cpu(infp, raw_sb->vs_free);
 85	bufp->f_bavail = 0;
 86	bufp->f_files = 0;
 87	bufp->f_ffree = fs32_to_cpu(infp, raw_sb->vs_ifree);
 88	bufp->f_fsid = u64_to_fsid(id);
 89	bufp->f_namelen = VXFS_NAMELEN;
 90
 91	return 0;
 92}
 93
 94static int vxfs_reconfigure(struct fs_context *fc)
 95{
 96	sync_filesystem(fc->root->d_sb);
 97	fc->sb_flags |= SB_RDONLY;
 98	return 0;
 99}
100
101static struct inode *vxfs_alloc_inode(struct super_block *sb)
102{
103	struct vxfs_inode_info *vi;
104
105	vi = alloc_inode_sb(sb, vxfs_inode_cachep, GFP_KERNEL);
106	if (!vi)
107		return NULL;
108	inode_init_once(&vi->vfs_inode);
109	return &vi->vfs_inode;
110}
111
112static void vxfs_free_inode(struct inode *inode)
113{
114	kmem_cache_free(vxfs_inode_cachep, VXFS_INO(inode));
115}
116
117static const struct super_operations vxfs_super_ops = {
118	.alloc_inode		= vxfs_alloc_inode,
119	.free_inode		= vxfs_free_inode,
120	.evict_inode		= vxfs_evict_inode,
121	.put_super		= vxfs_put_super,
122	.statfs			= vxfs_statfs,
123};
124
125static int vxfs_try_sb_magic(struct super_block *sbp, struct fs_context *fc,
126		unsigned blk, __fs32 magic)
127{
128	struct buffer_head *bp;
129	struct vxfs_sb *rsbp;
130	struct vxfs_sb_info *infp = VXFS_SBI(sbp);
131	int silent = fc->sb_flags & SB_SILENT;
132	int rc = -ENOMEM;
133
134	bp = sb_bread(sbp, blk);
135	do {
136		if (!bp || !buffer_mapped(bp)) {
137			if (!silent) {
138				warnf(fc,
139				      "vxfs: unable to read disk superblock at %u",
140				      blk);
141			}
142			break;
143		}
144
145		rc = -EINVAL;
146		rsbp = (struct vxfs_sb *)bp->b_data;
147		if (rsbp->vs_magic != magic) {
148			if (!silent)
149				infof(fc,
150				      "vxfs: WRONG superblock magic %08x at %u",
151				      rsbp->vs_magic, blk);
152			break;
153		}
154
155		rc = 0;
156		infp->vsi_raw = rsbp;
157		infp->vsi_bp = bp;
158	} while (0);
159
160	if (rc) {
161		infp->vsi_raw = NULL;
162		infp->vsi_bp = NULL;
163		brelse(bp);
164	}
165
166	return rc;
167}
168
169/**
170 * vxfs_fill_super - read superblock into memory and initialize filesystem
171 * @sbp:		VFS superblock (to fill)
172 * @fc:			filesytem context
173 *
174 * Description:
175 *   We are called on the first mount of a filesystem to read the
176 *   superblock into memory and do some basic setup.
177 *
178 * Returns:
179 *   The superblock on success, else %NULL.
180 *
181 * Locking:
182 *   We are under @sbp->s_lock.
183 */
184static int vxfs_fill_super(struct super_block *sbp, struct fs_context *fc)
185{
186	struct vxfs_sb_info	*infp;
187	struct vxfs_sb		*rsbp;
188	u_long			bsize;
189	struct inode *root;
190	int ret = -EINVAL;
191	int silent = fc->sb_flags & SB_SILENT;
192	u32 j;
193
194	sbp->s_flags |= SB_RDONLY;
195
196	infp = kzalloc(sizeof(*infp), GFP_KERNEL);
197	if (!infp) {
198		warnf(fc, "vxfs: unable to allocate incore superblock");
199		return -ENOMEM;
200	}
201
202	bsize = sb_min_blocksize(sbp, BLOCK_SIZE);
203	if (!bsize) {
204		warnf(fc, "vxfs: unable to set blocksize");
205		goto out;
206	}
207
208	sbp->s_op = &vxfs_super_ops;
209	sbp->s_fs_info = infp;
210	sbp->s_time_min = 0;
211	sbp->s_time_max = U32_MAX;
212
213	if (!vxfs_try_sb_magic(sbp, fc, 1,
214			(__force __fs32)cpu_to_le32(VXFS_SUPER_MAGIC))) {
215		/* Unixware, x86 */
216		infp->byte_order = VXFS_BO_LE;
217	} else if (!vxfs_try_sb_magic(sbp, fc, 8,
218			(__force __fs32)cpu_to_be32(VXFS_SUPER_MAGIC))) {
219		/* HP-UX, parisc */
220		infp->byte_order = VXFS_BO_BE;
221	} else {
222		if (!silent)
223			infof(fc, "vxfs: can't find superblock.");
224		goto out;
225	}
226
227	rsbp = infp->vsi_raw;
228	j = fs32_to_cpu(infp, rsbp->vs_version);
229	if ((j < 2 || j > 4) && !silent) {
230		infof(fc, "vxfs: unsupported VxFS version (%d)", j);
231		goto out;
232	}
233
234#ifdef DIAGNOSTIC
235	printk(KERN_DEBUG "vxfs: supported VxFS version (%d)\n", j);
236	printk(KERN_DEBUG "vxfs: blocksize: %d\n",
237		fs32_to_cpu(infp, rsbp->vs_bsize));
238#endif
239
240	sbp->s_magic = fs32_to_cpu(infp, rsbp->vs_magic);
241
242	infp->vsi_oltext = fs32_to_cpu(infp, rsbp->vs_oltext[0]);
243	infp->vsi_oltsize = fs32_to_cpu(infp, rsbp->vs_oltsize);
244
245	j = fs32_to_cpu(infp, rsbp->vs_bsize);
246	if (!sb_set_blocksize(sbp, j)) {
247		warnf(fc, "vxfs: unable to set final block size");
248		goto out;
249	}
250
251	if (vxfs_read_olt(sbp, bsize)) {
252		warnf(fc, "vxfs: unable to read olt");
253		goto out;
254	}
255
256	if (vxfs_read_fshead(sbp)) {
257		warnf(fc, "vxfs: unable to read fshead");
258		goto out;
259	}
260
261	root = vxfs_iget(sbp, VXFS_ROOT_INO);
262	if (IS_ERR(root)) {
263		ret = PTR_ERR(root);
264		goto out;
265	}
266	sbp->s_root = d_make_root(root);
267	if (!sbp->s_root) {
268		warnf(fc, "vxfs: unable to get root dentry.");
269		goto out_free_ilist;
270	}
271
272	return 0;
273	
274out_free_ilist:
275	iput(infp->vsi_fship);
276	iput(infp->vsi_ilist);
277	iput(infp->vsi_stilist);
278out:
279	brelse(infp->vsi_bp);
280	kfree(infp);
281	return ret;
282}
283
284/*
285 * The usual module blurb.
286 */
287static int vxfs_get_tree(struct fs_context *fc)
288{
289	return get_tree_bdev(fc, vxfs_fill_super);
290}
291
292static const struct fs_context_operations vxfs_context_ops = {
293	.get_tree	= vxfs_get_tree,
294	.reconfigure	= vxfs_reconfigure,
295};
296
297static int vxfs_init_fs_context(struct fs_context *fc)
298{
299	fc->ops = &vxfs_context_ops;
300
301	return 0;
302}
303
304static struct file_system_type vxfs_fs_type = {
305	.owner		= THIS_MODULE,
306	.name		= "vxfs",
307	.kill_sb	= kill_block_super,
308	.fs_flags	= FS_REQUIRES_DEV,
309	.init_fs_context = vxfs_init_fs_context,
310};
311MODULE_ALIAS_FS("vxfs"); /* makes mount -t vxfs autoload the module */
312MODULE_ALIAS("vxfs");
313
314static int __init
315vxfs_init(void)
316{
317	int rv;
318
319	vxfs_inode_cachep = kmem_cache_create_usercopy("vxfs_inode",
320			sizeof(struct vxfs_inode_info), 0,
321			SLAB_RECLAIM_ACCOUNT,
322			offsetof(struct vxfs_inode_info, vii_immed.vi_immed),
323			sizeof_field(struct vxfs_inode_info,
324				vii_immed.vi_immed),
325			NULL);
326	if (!vxfs_inode_cachep)
327		return -ENOMEM;
328	rv = register_filesystem(&vxfs_fs_type);
329	if (rv < 0)
330		kmem_cache_destroy(vxfs_inode_cachep);
331	return rv;
332}
333
334static void __exit
335vxfs_cleanup(void)
336{
337	unregister_filesystem(&vxfs_fs_type);
338	/*
339	 * Make sure all delayed rcu free inodes are flushed before we
340	 * destroy cache.
341	 */
342	rcu_barrier();
343	kmem_cache_destroy(vxfs_inode_cachep);
344}
345
346module_init(vxfs_init);
347module_exit(vxfs_cleanup);