~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/s390/hypfs/inode.c

Version: ~ [ linux-5.18-rc6 ] ~ [ linux-5.17.6 ] ~ [ linux-5.16.20 ] ~ [ linux-5.15.38 ] ~ [ linux-5.14.21 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.114 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.192 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.241 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.277 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.312 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.302 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.9 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 // SPDX-License-Identifier: GPL-1.0+
  2 /*
  3  *    Hypervisor filesystem for Linux on s390.
  4  *
  5  *    Copyright IBM Corp. 2006, 2008
  6  *    Author(s): Michael Holzheu <holzheu@de.ibm.com>
  7  */
  8 
  9 #define KMSG_COMPONENT "hypfs"
 10 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 11 
 12 #include <linux/types.h>
 13 #include <linux/errno.h>
 14 #include <linux/fs.h>
 15 #include <linux/fs_context.h>
 16 #include <linux/fs_parser.h>
 17 #include <linux/namei.h>
 18 #include <linux/vfs.h>
 19 #include <linux/slab.h>
 20 #include <linux/pagemap.h>
 21 #include <linux/time.h>
 22 #include <linux/sysfs.h>
 23 #include <linux/init.h>
 24 #include <linux/kobject.h>
 25 #include <linux/seq_file.h>
 26 #include <linux/uio.h>
 27 #include <asm/ebcdic.h>
 28 #include "hypfs.h"
 29 
 30 #define HYPFS_MAGIC 0x687970    /* ASCII 'hyp' */
 31 #define TMP_SIZE 64             /* size of temporary buffers */
 32 
 33 static struct dentry *hypfs_create_update_file(struct dentry *dir);
 34 
 35 struct hypfs_sb_info {
 36         kuid_t uid;                     /* uid used for files and dirs */
 37         kgid_t gid;                     /* gid used for files and dirs */
 38         struct dentry *update_file;     /* file to trigger update */
 39         time64_t last_update;           /* last update, CLOCK_MONOTONIC time */
 40         struct mutex lock;              /* lock to protect update process */
 41 };
 42 
 43 static const struct file_operations hypfs_file_ops;
 44 static struct file_system_type hypfs_type;
 45 static const struct super_operations hypfs_s_ops;
 46 
 47 /* start of list of all dentries, which have to be deleted on update */
 48 static struct dentry *hypfs_last_dentry;
 49 
 50 static void hypfs_update_update(struct super_block *sb)
 51 {
 52         struct hypfs_sb_info *sb_info = sb->s_fs_info;
 53         struct inode *inode = d_inode(sb_info->update_file);
 54 
 55         sb_info->last_update = ktime_get_seconds();
 56         inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
 57 }
 58 
 59 /* directory tree removal functions */
 60 
 61 static void hypfs_add_dentry(struct dentry *dentry)
 62 {
 63         dentry->d_fsdata = hypfs_last_dentry;
 64         hypfs_last_dentry = dentry;
 65 }
 66 
 67 static void hypfs_remove(struct dentry *dentry)
 68 {
 69         struct dentry *parent;
 70 
 71         parent = dentry->d_parent;
 72         inode_lock(d_inode(parent));
 73         if (simple_positive(dentry)) {
 74                 if (d_is_dir(dentry))
 75                         simple_rmdir(d_inode(parent), dentry);
 76                 else
 77                         simple_unlink(d_inode(parent), dentry);
 78         }
 79         d_drop(dentry);
 80         dput(dentry);
 81         inode_unlock(d_inode(parent));
 82 }
 83 
 84 static void hypfs_delete_tree(struct dentry *root)
 85 {
 86         while (hypfs_last_dentry) {
 87                 struct dentry *next_dentry;
 88                 next_dentry = hypfs_last_dentry->d_fsdata;
 89                 hypfs_remove(hypfs_last_dentry);
 90                 hypfs_last_dentry = next_dentry;
 91         }
 92 }
 93 
 94 static struct inode *hypfs_make_inode(struct super_block *sb, umode_t mode)
 95 {
 96         struct inode *ret = new_inode(sb);
 97 
 98         if (ret) {
 99                 struct hypfs_sb_info *hypfs_info = sb->s_fs_info;
100                 ret->i_ino = get_next_ino();
101                 ret->i_mode = mode;
102                 ret->i_uid = hypfs_info->uid;
103                 ret->i_gid = hypfs_info->gid;
104                 ret->i_atime = ret->i_mtime = ret->i_ctime = current_time(ret);
105                 if (S_ISDIR(mode))
106                         set_nlink(ret, 2);
107         }
108         return ret;
109 }
110 
111 static void hypfs_evict_inode(struct inode *inode)
112 {
113         clear_inode(inode);
114         kfree(inode->i_private);
115 }
116 
117 static int hypfs_open(struct inode *inode, struct file *filp)
118 {
119         char *data = file_inode(filp)->i_private;
120         struct hypfs_sb_info *fs_info;
121 
122         if (filp->f_mode & FMODE_WRITE) {
123                 if (!(inode->i_mode & S_IWUGO))
124                         return -EACCES;
125         }
126         if (filp->f_mode & FMODE_READ) {
127                 if (!(inode->i_mode & S_IRUGO))
128                         return -EACCES;
129         }
130 
131         fs_info = inode->i_sb->s_fs_info;
132         if(data) {
133                 mutex_lock(&fs_info->lock);
134                 filp->private_data = kstrdup(data, GFP_KERNEL);
135                 if (!filp->private_data) {
136                         mutex_unlock(&fs_info->lock);
137                         return -ENOMEM;
138                 }
139                 mutex_unlock(&fs_info->lock);
140         }
141         return nonseekable_open(inode, filp);
142 }
143 
144 static ssize_t hypfs_read_iter(struct kiocb *iocb, struct iov_iter *to)
145 {
146         struct file *file = iocb->ki_filp;
147         char *data = file->private_data;
148         size_t available = strlen(data);
149         loff_t pos = iocb->ki_pos;
150         size_t count;
151 
152         if (pos < 0)
153                 return -EINVAL;
154         if (pos >= available || !iov_iter_count(to))
155                 return 0;
156         count = copy_to_iter(data + pos, available - pos, to);
157         if (!count)
158                 return -EFAULT;
159         iocb->ki_pos = pos + count;
160         file_accessed(file);
161         return count;
162 }
163 
164 static ssize_t hypfs_write_iter(struct kiocb *iocb, struct iov_iter *from)
165 {
166         int rc;
167         struct super_block *sb = file_inode(iocb->ki_filp)->i_sb;
168         struct hypfs_sb_info *fs_info = sb->s_fs_info;
169         size_t count = iov_iter_count(from);
170 
171         /*
172          * Currently we only allow one update per second for two reasons:
173          * 1. diag 204 is VERY expensive
174          * 2. If several processes do updates in parallel and then read the
175          *    hypfs data, the likelihood of collisions is reduced, if we restrict
176          *    the minimum update interval. A collision occurs, if during the
177          *    data gathering of one process another process triggers an update
178          *    If the first process wants to ensure consistent data, it has
179          *    to restart data collection in this case.
180          */
181         mutex_lock(&fs_info->lock);
182         if (fs_info->last_update == ktime_get_seconds()) {
183                 rc = -EBUSY;
184                 goto out;
185         }
186         hypfs_delete_tree(sb->s_root);
187         if (MACHINE_IS_VM)
188                 rc = hypfs_vm_create_files(sb->s_root);
189         else
190                 rc = hypfs_diag_create_files(sb->s_root);
191         if (rc) {
192                 pr_err("Updating the hypfs tree failed\n");
193                 hypfs_delete_tree(sb->s_root);
194                 goto out;
195         }
196         hypfs_update_update(sb);
197         rc = count;
198         iov_iter_advance(from, count);
199 out:
200         mutex_unlock(&fs_info->lock);
201         return rc;
202 }
203 
204 static int hypfs_release(struct inode *inode, struct file *filp)
205 {
206         kfree(filp->private_data);
207         return 0;
208 }
209 
210 enum { Opt_uid, Opt_gid, };
211 
212 static const struct fs_parameter_spec hypfs_fs_parameters[] = {
213         fsparam_u32("gid", Opt_gid),
214         fsparam_u32("uid", Opt_uid),
215         {}
216 };
217 
218 static int hypfs_parse_param(struct fs_context *fc, struct fs_parameter *param)
219 {
220         struct hypfs_sb_info *hypfs_info = fc->s_fs_info;
221         struct fs_parse_result result;
222         kuid_t uid;
223         kgid_t gid;
224         int opt;
225 
226         opt = fs_parse(fc, hypfs_fs_parameters, param, &result);
227         if (opt < 0)
228                 return opt;
229 
230         switch (opt) {
231         case Opt_uid:
232                 uid = make_kuid(current_user_ns(), result.uint_32);
233                 if (!uid_valid(uid))
234                         return invalf(fc, "Unknown uid");
235                 hypfs_info->uid = uid;
236                 break;
237         case Opt_gid:
238                 gid = make_kgid(current_user_ns(), result.uint_32);
239                 if (!gid_valid(gid))
240                         return invalf(fc, "Unknown gid");
241                 hypfs_info->gid = gid;
242                 break;
243         }
244         return 0;
245 }
246 
247 static int hypfs_show_options(struct seq_file *s, struct dentry *root)
248 {
249         struct hypfs_sb_info *hypfs_info = root->d_sb->s_fs_info;
250 
251         seq_printf(s, ",uid=%u", from_kuid_munged(&init_user_ns, hypfs_info->uid));
252         seq_printf(s, ",gid=%u", from_kgid_munged(&init_user_ns, hypfs_info->gid));
253         return 0;
254 }
255 
256 static int hypfs_fill_super(struct super_block *sb, struct fs_context *fc)
257 {
258         struct hypfs_sb_info *sbi = sb->s_fs_info;
259         struct inode *root_inode;
260         struct dentry *root_dentry, *update_file;
261         int rc;
262 
263         sb->s_blocksize = PAGE_SIZE;
264         sb->s_blocksize_bits = PAGE_SHIFT;
265         sb->s_magic = HYPFS_MAGIC;
266         sb->s_op = &hypfs_s_ops;
267 
268         root_inode = hypfs_make_inode(sb, S_IFDIR | 0755);
269         if (!root_inode)
270                 return -ENOMEM;
271         root_inode->i_op = &simple_dir_inode_operations;
272         root_inode->i_fop = &simple_dir_operations;
273         sb->s_root = root_dentry = d_make_root(root_inode);
274         if (!root_dentry)
275                 return -ENOMEM;
276         if (MACHINE_IS_VM)
277                 rc = hypfs_vm_create_files(root_dentry);
278         else
279                 rc = hypfs_diag_create_files(root_dentry);
280         if (rc)
281                 return rc;
282         update_file = hypfs_create_update_file(root_dentry);
283         if (IS_ERR(update_file))
284                 return PTR_ERR(update_file);
285         sbi->update_file = update_file;
286         hypfs_update_update(sb);
287         pr_info("Hypervisor filesystem mounted\n");
288         return 0;
289 }
290 
291 static int hypfs_get_tree(struct fs_context *fc)
292 {
293         return get_tree_single(fc, hypfs_fill_super);
294 }
295 
296 static void hypfs_free_fc(struct fs_context *fc)
297 {
298         kfree(fc->s_fs_info);
299 }
300 
301 static const struct fs_context_operations hypfs_context_ops = {
302         .free           = hypfs_free_fc,
303         .parse_param    = hypfs_parse_param,
304         .get_tree       = hypfs_get_tree,
305 };
306 
307 static int hypfs_init_fs_context(struct fs_context *fc)
308 {
309         struct hypfs_sb_info *sbi;
310 
311         sbi = kzalloc(sizeof(struct hypfs_sb_info), GFP_KERNEL);
312         if (!sbi)
313                 return -ENOMEM;
314 
315         mutex_init(&sbi->lock);
316         sbi->uid = current_uid();
317         sbi->gid = current_gid();
318 
319         fc->s_fs_info = sbi;
320         fc->ops = &hypfs_context_ops;
321         return 0;
322 }
323 
324 static void hypfs_kill_super(struct super_block *sb)
325 {
326         struct hypfs_sb_info *sb_info = sb->s_fs_info;
327 
328         if (sb->s_root)
329                 hypfs_delete_tree(sb->s_root);
330         if (sb_info && sb_info->update_file)
331                 hypfs_remove(sb_info->update_file);
332         kfree(sb->s_fs_info);
333         sb->s_fs_info = NULL;
334         kill_litter_super(sb);
335 }
336 
337 static struct dentry *hypfs_create_file(struct dentry *parent, const char *name,
338                                         char *data, umode_t mode)
339 {
340         struct dentry *dentry;
341         struct inode *inode;
342 
343         inode_lock(d_inode(parent));
344         dentry = lookup_one_len(name, parent, strlen(name));
345         if (IS_ERR(dentry)) {
346                 dentry = ERR_PTR(-ENOMEM);
347                 goto fail;
348         }
349         inode = hypfs_make_inode(parent->d_sb, mode);
350         if (!inode) {
351                 dput(dentry);
352                 dentry = ERR_PTR(-ENOMEM);
353                 goto fail;
354         }
355         if (S_ISREG(mode)) {
356                 inode->i_fop = &hypfs_file_ops;
357                 if (data)
358                         inode->i_size = strlen(data);
359                 else
360                         inode->i_size = 0;
361         } else if (S_ISDIR(mode)) {
362                 inode->i_op = &simple_dir_inode_operations;
363                 inode->i_fop = &simple_dir_operations;
364                 inc_nlink(d_inode(parent));
365         } else
366                 BUG();
367         inode->i_private = data;
368         d_instantiate(dentry, inode);
369         dget(dentry);
370 fail:
371         inode_unlock(d_inode(parent));
372         return dentry;
373 }
374 
375 struct dentry *hypfs_mkdir(struct dentry *parent, const char *name)
376 {
377         struct dentry *dentry;
378 
379         dentry = hypfs_create_file(parent, name, NULL, S_IFDIR | DIR_MODE);
380         if (IS_ERR(dentry))
381                 return dentry;
382         hypfs_add_dentry(dentry);
383         return dentry;
384 }
385 
386 static struct dentry *hypfs_create_update_file(struct dentry *dir)
387 {
388         struct dentry *dentry;
389 
390         dentry = hypfs_create_file(dir, "update", NULL,
391                                    S_IFREG | UPDATE_FILE_MODE);
392         /*
393          * We do not put the update file on the 'delete' list with
394          * hypfs_add_dentry(), since it should not be removed when the tree
395          * is updated.
396          */
397         return dentry;
398 }
399 
400 struct dentry *hypfs_create_u64(struct dentry *dir,
401                                 const char *name, __u64 value)
402 {
403         char *buffer;
404         char tmp[TMP_SIZE];
405         struct dentry *dentry;
406 
407         snprintf(tmp, TMP_SIZE, "%llu\n", (unsigned long long int)value);
408         buffer = kstrdup(tmp, GFP_KERNEL);
409         if (!buffer)
410                 return ERR_PTR(-ENOMEM);
411         dentry =
412             hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
413         if (IS_ERR(dentry)) {
414                 kfree(buffer);
415                 return ERR_PTR(-ENOMEM);
416         }
417         hypfs_add_dentry(dentry);
418         return dentry;
419 }
420 
421 struct dentry *hypfs_create_str(struct dentry *dir,
422                                 const char *name, char *string)
423 {
424         char *buffer;
425         struct dentry *dentry;
426 
427         buffer = kmalloc(strlen(string) + 2, GFP_KERNEL);
428         if (!buffer)
429                 return ERR_PTR(-ENOMEM);
430         sprintf(buffer, "%s\n", string);
431         dentry =
432             hypfs_create_file(dir, name, buffer, S_IFREG | REG_FILE_MODE);
433         if (IS_ERR(dentry)) {
434                 kfree(buffer);
435                 return ERR_PTR(-ENOMEM);
436         }
437         hypfs_add_dentry(dentry);
438         return dentry;
439 }
440 
441 static const struct file_operations hypfs_file_ops = {
442         .open           = hypfs_open,
443         .release        = hypfs_release,
444         .read_iter      = hypfs_read_iter,
445         .write_iter     = hypfs_write_iter,
446         .llseek         = no_llseek,
447 };
448 
449 static struct file_system_type hypfs_type = {
450         .owner          = THIS_MODULE,
451         .name           = "s390_hypfs",
452         .init_fs_context = hypfs_init_fs_context,
453         .parameters     = hypfs_fs_parameters,
454         .kill_sb        = hypfs_kill_super
455 };
456 
457 static const struct super_operations hypfs_s_ops = {
458         .statfs         = simple_statfs,
459         .evict_inode    = hypfs_evict_inode,
460         .show_options   = hypfs_show_options,
461 };
462 
463 static int __init hypfs_init(void)
464 {
465         int rc;
466 
467         hypfs_dbfs_init();
468 
469         if (hypfs_diag_init()) {
470                 rc = -ENODATA;
471                 goto fail_dbfs_exit;
472         }
473         if (hypfs_vm_init()) {
474                 rc = -ENODATA;
475                 goto fail_hypfs_diag_exit;
476         }
477         hypfs_sprp_init();
478         if (hypfs_diag0c_init()) {
479                 rc = -ENODATA;
480                 goto fail_hypfs_sprp_exit;
481         }
482         rc = sysfs_create_mount_point(hypervisor_kobj, "s390");
483         if (rc)
484                 goto fail_hypfs_diag0c_exit;
485         rc = register_filesystem(&hypfs_type);
486         if (rc)
487                 goto fail_filesystem;
488         return 0;
489 
490 fail_filesystem:
491         sysfs_remove_mount_point(hypervisor_kobj, "s390");
492 fail_hypfs_diag0c_exit:
493         hypfs_diag0c_exit();
494 fail_hypfs_sprp_exit:
495         hypfs_sprp_exit();
496         hypfs_vm_exit();
497 fail_hypfs_diag_exit:
498         hypfs_diag_exit();
499 fail_dbfs_exit:
500         hypfs_dbfs_exit();
501         pr_err("Initialization of hypfs failed with rc=%i\n", rc);
502         return rc;
503 }
504 device_initcall(hypfs_init)
505 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp