Root/fs/coda/inode.c

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

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