xref: /openbmc/linux/fs/coda/inode.c (revision 8a0a6c9af053fb93c0edf4581518c77fd131803e)
1  // SPDX-License-Identifier: GPL-2.0
2  /*
3   * Super block/filesystem wide operations
4   *
5   * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and
6   * Michael Callahan <callahan@maths.ox.ac.uk>
7   *
8   * Rewritten for Linux 2.1.  Peter Braam <braam@cs.cmu.edu>
9   * Copyright (C) Carnegie Mellon University
10   */
11  
12  #include <linux/module.h>
13  #include <linux/kernel.h>
14  #include <linux/mm.h>
15  #include <linux/string.h>
16  #include <linux/stat.h>
17  #include <linux/errno.h>
18  #include <linux/unistd.h>
19  #include <linux/mutex.h>
20  #include <linux/spinlock.h>
21  #include <linux/file.h>
22  #include <linux/vfs.h>
23  #include <linux/slab.h>
24  #include <linux/pid_namespace.h>
25  #include <linux/uaccess.h>
26  #include <linux/fs.h>
27  #include <linux/vmalloc.h>
28  
29  #include <linux/coda.h>
30  #include "coda_psdev.h"
31  #include "coda_linux.h"
32  #include "coda_cache.h"
33  
34  #include "coda_int.h"
35  
36  /* VFS super_block ops */
37  static void coda_evict_inode(struct inode *);
38  static void coda_put_super(struct super_block *);
39  static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
40  
41  static struct kmem_cache * coda_inode_cachep;
42  
43  static struct inode *coda_alloc_inode(struct super_block *sb)
44  {
45  	struct coda_inode_info *ei;
46  	ei = alloc_inode_sb(sb, coda_inode_cachep, GFP_KERNEL);
47  	if (!ei)
48  		return NULL;
49  	memset(&ei->c_fid, 0, sizeof(struct CodaFid));
50  	ei->c_flags = 0;
51  	ei->c_uid = GLOBAL_ROOT_UID;
52  	ei->c_cached_perm = 0;
53  	spin_lock_init(&ei->c_lock);
54  	return &ei->vfs_inode;
55  }
56  
57  static void coda_free_inode(struct inode *inode)
58  {
59  	kmem_cache_free(coda_inode_cachep, ITOC(inode));
60  }
61  
62  static void init_once(void *foo)
63  {
64  	struct coda_inode_info *ei = (struct coda_inode_info *) foo;
65  
66  	inode_init_once(&ei->vfs_inode);
67  }
68  
69  int __init coda_init_inodecache(void)
70  {
71  	coda_inode_cachep = kmem_cache_create("coda_inode_cache",
72  				sizeof(struct coda_inode_info), 0,
73  				SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD|
74  				SLAB_ACCOUNT, init_once);
75  	if (coda_inode_cachep == NULL)
76  		return -ENOMEM;
77  	return 0;
78  }
79  
80  void coda_destroy_inodecache(void)
81  {
82  	/*
83  	 * Make sure all delayed rcu free inodes are flushed before we
84  	 * destroy cache.
85  	 */
86  	rcu_barrier();
87  	kmem_cache_destroy(coda_inode_cachep);
88  }
89  
90  static int coda_remount(struct super_block *sb, int *flags, char *data)
91  {
92  	sync_filesystem(sb);
93  	*flags |= SB_NOATIME;
94  	return 0;
95  }
96  
97  /* exported operations */
98  static const struct super_operations coda_super_operations =
99  {
100  	.alloc_inode	= coda_alloc_inode,
101  	.free_inode	= coda_free_inode,
102  	.evict_inode	= coda_evict_inode,
103  	.put_super	= coda_put_super,
104  	.statfs		= coda_statfs,
105  	.remount_fs	= coda_remount,
106  };
107  
108  static int get_device_index(struct coda_mount_data *data)
109  {
110  	struct fd f;
111  	struct inode *inode;
112  	int idx;
113  
114  	if (data == NULL) {
115  		pr_warn("%s: Bad mount data\n", __func__);
116  		return -1;
117  	}
118  
119  	if (data->version != CODA_MOUNT_VERSION) {
120  		pr_warn("%s: Bad mount version\n", __func__);
121  		return -1;
122  	}
123  
124  	f = fdget(data->fd);
125  	if (!f.file)
126  		goto Ebadf;
127  	inode = file_inode(f.file);
128  	if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
129  		fdput(f);
130  		goto Ebadf;
131  	}
132  
133  	idx = iminor(inode);
134  	fdput(f);
135  
136  	if (idx < 0 || idx >= MAX_CODADEVS) {
137  		pr_warn("%s: Bad minor number\n", __func__);
138  		return -1;
139  	}
140  
141  	return idx;
142  Ebadf:
143  	pr_warn("%s: Bad file\n", __func__);
144  	return -1;
145  }
146  
147  static int coda_fill_super(struct super_block *sb, void *data, int silent)
148  {
149  	struct inode *root = NULL;
150  	struct venus_comm *vc;
151  	struct CodaFid fid;
152  	int error;
153  	int idx;
154  
155  	if (task_active_pid_ns(current) != &init_pid_ns)
156  		return -EINVAL;
157  
158  	idx = get_device_index((struct coda_mount_data *) data);
159  
160  	/* Ignore errors in data, for backward compatibility */
161  	if(idx == -1)
162  		idx = 0;
163  
164  	pr_info("%s: device index: %i\n", __func__,  idx);
165  
166  	vc = &coda_comms[idx];
167  	mutex_lock(&vc->vc_mutex);
168  
169  	if (!vc->vc_inuse) {
170  		pr_warn("%s: No pseudo device\n", __func__);
171  		error = -EINVAL;
172  		goto unlock_out;
173  	}
174  
175  	if (vc->vc_sb) {
176  		pr_warn("%s: Device already mounted\n", __func__);
177  		error = -EBUSY;
178  		goto unlock_out;
179  	}
180  
181  	vc->vc_sb = sb;
182  	mutex_unlock(&vc->vc_mutex);
183  
184  	sb->s_fs_info = vc;
185  	sb->s_flags |= SB_NOATIME;
186  	sb->s_blocksize = 4096;	/* XXXXX  what do we put here?? */
187  	sb->s_blocksize_bits = 12;
188  	sb->s_magic = CODA_SUPER_MAGIC;
189  	sb->s_op = &coda_super_operations;
190  	sb->s_d_op = &coda_dentry_operations;
191  	sb->s_time_gran = 1;
192  	sb->s_time_min = S64_MIN;
193  	sb->s_time_max = S64_MAX;
194  
195  	error = super_setup_bdi(sb);
196  	if (error)
197  		goto error;
198  
199  	/* get root fid from Venus: this needs the root inode */
200  	error = venus_rootfid(sb, &fid);
201  	if ( error ) {
202  		pr_warn("%s: coda_get_rootfid failed with %d\n",
203  			__func__, error);
204  		goto error;
205  	}
206  	pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
207  
208  	/* make root inode */
209          root = coda_cnode_make(&fid, sb);
210          if (IS_ERR(root)) {
211  		error = PTR_ERR(root);
212  		pr_warn("Failure of coda_cnode_make for root: error %d\n",
213  			error);
214  		goto error;
215  	}
216  
217  	pr_info("%s: rootinode is %ld dev %s\n",
218  		__func__, root->i_ino, root->i_sb->s_id);
219  	sb->s_root = d_make_root(root);
220  	if (!sb->s_root) {
221  		error = -EINVAL;
222  		goto error;
223  	}
224  	return 0;
225  
226  error:
227  	mutex_lock(&vc->vc_mutex);
228  	vc->vc_sb = NULL;
229  	sb->s_fs_info = NULL;
230  unlock_out:
231  	mutex_unlock(&vc->vc_mutex);
232  	return error;
233  }
234  
235  static void coda_put_super(struct super_block *sb)
236  {
237  	struct venus_comm *vcp = coda_vcp(sb);
238  	mutex_lock(&vcp->vc_mutex);
239  	vcp->vc_sb = NULL;
240  	sb->s_fs_info = NULL;
241  	mutex_unlock(&vcp->vc_mutex);
242  	mutex_destroy(&vcp->vc_mutex);
243  
244  	pr_info("Bye bye.\n");
245  }
246  
247  static void coda_evict_inode(struct inode *inode)
248  {
249  	truncate_inode_pages_final(&inode->i_data);
250  	clear_inode(inode);
251  	coda_cache_clear_inode(inode);
252  }
253  
254  int coda_getattr(struct mnt_idmap *idmap, const struct path *path,
255  		 struct kstat *stat, u32 request_mask, unsigned int flags)
256  {
257  	int err = coda_revalidate_inode(d_inode(path->dentry));
258  	if (!err)
259  		generic_fillattr(&nop_mnt_idmap, d_inode(path->dentry), stat);
260  	return err;
261  }
262  
263  int coda_setattr(struct mnt_idmap *idmap, struct dentry *de,
264  		 struct iattr *iattr)
265  {
266  	struct inode *inode = d_inode(de);
267  	struct coda_vattr vattr;
268  	int error;
269  
270  	memset(&vattr, 0, sizeof(vattr));
271  
272  	inode->i_ctime = current_time(inode);
273  	coda_iattr_to_vattr(iattr, &vattr);
274  	vattr.va_type = C_VNON; /* cannot set type */
275  
276  	/* Venus is responsible for truncating the container-file!!! */
277  	error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
278  
279  	if (!error) {
280  	        coda_vattr_to_iattr(inode, &vattr);
281  		coda_cache_clear_inode(inode);
282  	}
283  	return error;
284  }
285  
286  const struct inode_operations coda_file_inode_operations = {
287  	.permission	= coda_permission,
288  	.getattr	= coda_getattr,
289  	.setattr	= coda_setattr,
290  };
291  
292  static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
293  {
294  	int error;
295  
296  	error = venus_statfs(dentry, buf);
297  
298  	if (error) {
299  		/* fake something like AFS does */
300  		buf->f_blocks = 9000000;
301  		buf->f_bfree  = 9000000;
302  		buf->f_bavail = 9000000;
303  		buf->f_files  = 9000000;
304  		buf->f_ffree  = 9000000;
305  	}
306  
307  	/* and fill in the rest */
308  	buf->f_type = CODA_SUPER_MAGIC;
309  	buf->f_bsize = 4096;
310  	buf->f_namelen = CODA_MAXNAMLEN;
311  
312  	return 0;
313  }
314  
315  /* init_coda: used by filesystems.c to register coda */
316  
317  static struct dentry *coda_mount(struct file_system_type *fs_type,
318  	int flags, const char *dev_name, void *data)
319  {
320  	return mount_nodev(fs_type, flags, data, coda_fill_super);
321  }
322  
323  struct file_system_type coda_fs_type = {
324  	.owner		= THIS_MODULE,
325  	.name		= "coda",
326  	.mount		= coda_mount,
327  	.kill_sb	= kill_anon_super,
328  	.fs_flags	= FS_BINARY_MOUNTDATA,
329  };
330  MODULE_ALIAS_FS("coda");
331  
332