ia64/linux-2.6.18-xen.hg

view drivers/oprofile/oprofilefs.c @ 893:f994bfe9b93b

linux/blktap2: reduce TLB flush scope

c/s 885 added very coarse TLB flushing. Since these flushes always
follow single page updates, single page flushes (when available) are
sufficient.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Jun 04 10:32:57 2009 +0100 (2009-06-04)
parents 831230e53067
children
line source
1 /**
2 * @file oprofilefs.c
3 *
4 * @remark Copyright 2002 OProfile authors
5 * @remark Read the file COPYING
6 *
7 * @author John Levon
8 *
9 * A simple filesystem for configuration and
10 * access of oprofile.
11 */
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/oprofile.h>
16 #include <linux/fs.h>
17 #include <linux/pagemap.h>
18 #include <asm/uaccess.h>
20 #include "oprof.h"
22 #define OPROFILEFS_MAGIC 0x6f70726f
24 DEFINE_SPINLOCK(oprofilefs_lock);
26 static struct inode * oprofilefs_get_inode(struct super_block * sb, int mode)
27 {
28 struct inode * inode = new_inode(sb);
30 if (inode) {
31 inode->i_mode = mode;
32 inode->i_uid = 0;
33 inode->i_gid = 0;
34 inode->i_blksize = PAGE_CACHE_SIZE;
35 inode->i_blocks = 0;
36 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
37 }
38 return inode;
39 }
42 static struct super_operations s_ops = {
43 .statfs = simple_statfs,
44 .drop_inode = generic_delete_inode,
45 };
48 ssize_t oprofilefs_str_to_user(char const * str, char __user * buf, size_t count, loff_t * offset)
49 {
50 return simple_read_from_buffer(buf, count, offset, str, strlen(str));
51 }
54 #define TMPBUFSIZE 50
56 ssize_t oprofilefs_ulong_to_user(unsigned long val, char __user * buf, size_t count, loff_t * offset)
57 {
58 char tmpbuf[TMPBUFSIZE];
59 size_t maxlen = snprintf(tmpbuf, TMPBUFSIZE, "%lu\n", val);
60 if (maxlen > TMPBUFSIZE)
61 maxlen = TMPBUFSIZE;
62 return simple_read_from_buffer(buf, count, offset, tmpbuf, maxlen);
63 }
66 int oprofilefs_ulong_from_user(unsigned long * val, char const __user * buf, size_t count)
67 {
68 char tmpbuf[TMPBUFSIZE];
70 if (!count)
71 return 0;
73 if (count > TMPBUFSIZE - 1)
74 return -EINVAL;
76 memset(tmpbuf, 0x0, TMPBUFSIZE);
78 if (copy_from_user(tmpbuf, buf, count))
79 return -EFAULT;
81 spin_lock(&oprofilefs_lock);
82 *val = simple_strtoul(tmpbuf, NULL, 0);
83 spin_unlock(&oprofilefs_lock);
84 return 0;
85 }
88 static ssize_t ulong_read_file(struct file * file, char __user * buf, size_t count, loff_t * offset)
89 {
90 unsigned long * val = file->private_data;
91 return oprofilefs_ulong_to_user(*val, buf, count, offset);
92 }
95 static ssize_t ulong_write_file(struct file * file, char const __user * buf, size_t count, loff_t * offset)
96 {
97 unsigned long * value = file->private_data;
98 int retval;
100 if (*offset)
101 return -EINVAL;
103 retval = oprofilefs_ulong_from_user(value, buf, count);
105 if (retval)
106 return retval;
107 return count;
108 }
111 static int default_open(struct inode * inode, struct file * filp)
112 {
113 if (inode->u.generic_ip)
114 filp->private_data = inode->u.generic_ip;
115 return 0;
116 }
119 static struct file_operations ulong_fops = {
120 .read = ulong_read_file,
121 .write = ulong_write_file,
122 .open = default_open,
123 };
126 static struct file_operations ulong_ro_fops = {
127 .read = ulong_read_file,
128 .open = default_open,
129 };
132 static struct dentry * __oprofilefs_create_file(struct super_block * sb,
133 struct dentry * root, char const * name, const struct file_operations * fops,
134 int perm)
135 {
136 struct dentry * dentry;
137 struct inode * inode;
139 dentry = d_alloc_name(root, name);
140 if (!dentry)
141 return NULL;
142 inode = oprofilefs_get_inode(sb, S_IFREG | perm);
143 if (!inode) {
144 dput(dentry);
145 return NULL;
146 }
147 inode->i_fop = fops;
148 d_add(dentry, inode);
149 return dentry;
150 }
153 int oprofilefs_create_ulong(struct super_block * sb, struct dentry * root,
154 char const * name, unsigned long * val)
155 {
156 struct dentry * d = __oprofilefs_create_file(sb, root, name,
157 &ulong_fops, 0644);
158 if (!d)
159 return -EFAULT;
161 d->d_inode->u.generic_ip = val;
162 return 0;
163 }
166 int oprofilefs_create_ro_ulong(struct super_block * sb, struct dentry * root,
167 char const * name, unsigned long * val)
168 {
169 struct dentry * d = __oprofilefs_create_file(sb, root, name,
170 &ulong_ro_fops, 0444);
171 if (!d)
172 return -EFAULT;
174 d->d_inode->u.generic_ip = val;
175 return 0;
176 }
179 static ssize_t atomic_read_file(struct file * file, char __user * buf, size_t count, loff_t * offset)
180 {
181 atomic_t * val = file->private_data;
182 return oprofilefs_ulong_to_user(atomic_read(val), buf, count, offset);
183 }
186 static struct file_operations atomic_ro_fops = {
187 .read = atomic_read_file,
188 .open = default_open,
189 };
192 int oprofilefs_create_ro_atomic(struct super_block * sb, struct dentry * root,
193 char const * name, atomic_t * val)
194 {
195 struct dentry * d = __oprofilefs_create_file(sb, root, name,
196 &atomic_ro_fops, 0444);
197 if (!d)
198 return -EFAULT;
200 d->d_inode->u.generic_ip = val;
201 return 0;
202 }
205 int oprofilefs_create_file(struct super_block * sb, struct dentry * root,
206 char const * name, const struct file_operations * fops)
207 {
208 if (!__oprofilefs_create_file(sb, root, name, fops, 0644))
209 return -EFAULT;
210 return 0;
211 }
214 int oprofilefs_create_file_perm(struct super_block * sb, struct dentry * root,
215 char const * name, const struct file_operations * fops, int perm)
216 {
217 if (!__oprofilefs_create_file(sb, root, name, fops, perm))
218 return -EFAULT;
219 return 0;
220 }
223 struct dentry * oprofilefs_mkdir(struct super_block * sb,
224 struct dentry * root, char const * name)
225 {
226 struct dentry * dentry;
227 struct inode * inode;
229 dentry = d_alloc_name(root, name);
230 if (!dentry)
231 return NULL;
232 inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
233 if (!inode) {
234 dput(dentry);
235 return NULL;
236 }
237 inode->i_op = &simple_dir_inode_operations;
238 inode->i_fop = &simple_dir_operations;
239 d_add(dentry, inode);
240 return dentry;
241 }
244 static int oprofilefs_fill_super(struct super_block * sb, void * data, int silent)
245 {
246 struct inode * root_inode;
247 struct dentry * root_dentry;
249 sb->s_blocksize = PAGE_CACHE_SIZE;
250 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
251 sb->s_magic = OPROFILEFS_MAGIC;
252 sb->s_op = &s_ops;
253 sb->s_time_gran = 1;
255 root_inode = oprofilefs_get_inode(sb, S_IFDIR | 0755);
256 if (!root_inode)
257 return -ENOMEM;
258 root_inode->i_op = &simple_dir_inode_operations;
259 root_inode->i_fop = &simple_dir_operations;
260 root_dentry = d_alloc_root(root_inode);
261 if (!root_dentry) {
262 iput(root_inode);
263 return -ENOMEM;
264 }
266 sb->s_root = root_dentry;
268 oprofile_create_files(sb, root_dentry);
270 // FIXME: verify kill_litter_super removes our dentries
271 return 0;
272 }
275 static int oprofilefs_get_sb(struct file_system_type *fs_type,
276 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
277 {
278 return get_sb_single(fs_type, flags, data, oprofilefs_fill_super, mnt);
279 }
282 static struct file_system_type oprofilefs_type = {
283 .owner = THIS_MODULE,
284 .name = "oprofilefs",
285 .get_sb = oprofilefs_get_sb,
286 .kill_sb = kill_litter_super,
287 };
290 int __init oprofilefs_register(void)
291 {
292 return register_filesystem(&oprofilefs_type);
293 }
296 void __exit oprofilefs_unregister(void)
297 {
298 unregister_filesystem(&oprofilefs_type);
299 }