Refactor procfs and sysfs support functions
[ext4-patch-queue.git] / refactor-sysfs-support
blobca933b675afc283d2b6bb4f891da378e04acc084
1 ext4: refactor sysfs support code
3 Make the code more easily extensible as well as taking up less
4 compiled space.
6 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
7 ---
8  fs/ext4/sysfs.c | 259 +++++++++++++++++++++++++++++++++++++++++------------------------------------------
9  1 file changed, 127 insertions(+), 132 deletions(-)
11 diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
12 index aeb90ca..1c3d32a 100644
13 --- a/fs/ext4/sysfs.c
14 +++ b/fs/ext4/sysfs.c
15 @@ -18,37 +18,35 @@
16  static const char *proc_dirname = "fs/ext4";
17  static struct proc_dir_entry *ext4_proc_root;
19 +typedef enum {
20 +       attr_noop,
21 +       attr_delayed_allocation_blocks,
22 +       attr_session_write_kbytes,
23 +       attr_lifetime_write_kbytes,
24 +       attr_reserved_clusters,
25 +       attr_inode_readahead,
26 +       attr_trigger_test_error,
27 +       attr_feature,
28 +       attr_pointer_ui,
29 +       attr_pointer_atomic,
30 +} attr_id_t;
32 +typedef enum {
33 +       ptr_explicit,
34 +       ptr_ext4_sb_info_offset,
35 +       ptr_ext4_super_block_offset,
36 +} attr_ptr_t;
38  struct ext4_attr {
39         struct attribute attr;
40 -       ssize_t (*show)(struct ext4_attr *, struct ext4_sb_info *, char *);
41 -       ssize_t (*store)(struct ext4_attr *, struct ext4_sb_info *,
42 -                        const char *, size_t);
43 +       short attr_id;
44 +       short attr_ptr;
45         union {
46                 int offset;
47 -               int deprecated_val;
48 +               void *explicit_ptr;
49         } u;
50  };
52 -static int parse_strtoull(const char *buf,
53 -               unsigned long long max, unsigned long long *value)
55 -       int ret;
57 -       ret = kstrtoull(skip_spaces(buf), 0, value);
58 -       if (!ret && *value > max)
59 -               ret = -EINVAL;
60 -       return ret;
63 -static ssize_t delayed_allocation_blocks_show(struct ext4_attr *a,
64 -                                             struct ext4_sb_info *sbi,
65 -                                             char *buf)
67 -       return snprintf(buf, PAGE_SIZE, "%llu\n",
68 -               (s64) EXT4_C2B(sbi,
69 -                       percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
72  static ssize_t session_write_kbytes_show(struct ext4_attr *a,
73                                          struct ext4_sb_info *sbi, char *buf)
74  {
75 @@ -92,46 +90,6 @@ static ssize_t inode_readahead_blks_store(struct ext4_attr *a,
76         return count;
77  }
79 -static ssize_t sbi_ui_show(struct ext4_attr *a,
80 -                          struct ext4_sb_info *sbi, char *buf)
82 -       unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
84 -       return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
87 -static ssize_t sbi_ui_store(struct ext4_attr *a,
88 -                           struct ext4_sb_info *sbi,
89 -                           const char *buf, size_t count)
91 -       unsigned int *ui = (unsigned int *) (((char *) sbi) + a->u.offset);
92 -       unsigned long t;
93 -       int ret;
95 -       ret = kstrtoul(skip_spaces(buf), 0, &t);
96 -       if (ret)
97 -               return ret;
98 -       *ui = t;
99 -       return count;
102 -static ssize_t es_ui_show(struct ext4_attr *a,
103 -                          struct ext4_sb_info *sbi, char *buf)
106 -       unsigned int *ui = (unsigned int *) (((char *) sbi->s_es) +
107 -                          a->u.offset);
109 -       return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
112 -static ssize_t reserved_clusters_show(struct ext4_attr *a,
113 -                                 struct ext4_sb_info *sbi, char *buf)
115 -       return snprintf(buf, PAGE_SIZE, "%llu\n",
116 -               (unsigned long long) atomic64_read(&sbi->s_resv_clusters));
119  static ssize_t reserved_clusters_store(struct ext4_attr *a,
120                                    struct ext4_sb_info *sbi,
121                                    const char *buf, size_t count)
122 @@ -139,11 +97,10 @@ static ssize_t reserved_clusters_store(struct ext4_attr *a,
123         unsigned long long val;
124         ext4_fsblk_t clusters = (ext4_blocks_count(sbi->s_es) >>
125                                  sbi->s_cluster_bits);
126 +       int ret;
128 -       if (parse_strtoull(buf, -1ULL, &val))
129 -               return -EINVAL;
131 -       if (val >= clusters)
132 +       ret = kstrtoull(skip_spaces(buf), 0, &val);
133 +       if (!ret || val >= clusters)
134                 return -EINVAL;
136         atomic64_set(&sbi->s_resv_clusters, val);
137 @@ -167,60 +124,51 @@ static ssize_t trigger_test_error(struct ext4_attr *a,
138         return count;
141 -static ssize_t sbi_deprecated_show(struct ext4_attr *a,
142 -                                  struct ext4_sb_info *sbi, char *buf)
144 -       return snprintf(buf, PAGE_SIZE, "%d\n", a->u.deprecated_val);
145 +#define EXT4_ATTR(_name,_mode,_id)                                     \
146 +static struct ext4_attr ext4_attr_##_name = {                          \
147 +       .attr = {.name = __stringify(_name), .mode = _mode },           \
148 +       .attr_id = attr_##_id,                                          \
151 -#define EXT4_ATTR_OFFSET(_name,_mode,_show,_store,_elname) \
152 +#define EXT4_ATTR_FUNC(_name,_mode)  EXT4_ATTR(_name,_mode,_name)
154 +#define EXT4_ATTR_FEATURE(_name)   EXT4_ATTR(_name, 0444, feature)
156 +#define EXT4_ATTR_OFFSET(_name,_mode,_id,_struct,_elname)      \
157  static struct ext4_attr ext4_attr_##_name = {                  \
158         .attr = {.name = __stringify(_name), .mode = _mode },   \
159 -       .show   = _show,                                        \
160 -       .store  = _store,                                       \
161 +       .attr_id = attr_##_id,                                  \
162 +       .attr_ptr = ptr_##_struct##_offset,                     \
163         .u = {                                                  \
164 -               .offset = offsetof(struct ext4_sb_info, _elname),\
165 +               .offset = offsetof(struct _struct, _elname),\
166         },                                                      \
169 -#define EXT4_ATTR_OFFSET_ES(_name,_mode,_show,_store,_elname)          \
170 -static struct ext4_attr ext4_attr_##_name = {                          \
171 -       .attr = {.name = __stringify(_name), .mode = _mode },           \
172 -       .show   = _show,                                                \
173 -       .store  = _store,                                               \
174 -       .u = {                                                          \
175 -               .offset = offsetof(struct ext4_super_block, _elname),   \
176 -       },                                                              \
179 -#define EXT4_ATTR(name, mode, show, store) \
180 -static struct ext4_attr ext4_attr_##name = __ATTR(name, mode, show, store)
182 -#define EXT4_INFO_ATTR(name) EXT4_ATTR(name, 0444, NULL, NULL)
183 -#define EXT4_RO_ATTR(name) EXT4_ATTR(name, 0444, name##_show, NULL)
184 -#define EXT4_RW_ATTR(name) EXT4_ATTR(name, 0644, name##_show, name##_store)
185 +#define EXT4_RO_ATTR_ES_UI(_name,_elname)                              \
186 +       EXT4_ATTR_OFFSET(_name, 0444, pointer_ui, ext4_super_block, _elname)
188 -#define EXT4_RO_ATTR_ES_UI(name, elname)       \
189 -       EXT4_ATTR_OFFSET_ES(name, 0444, es_ui_show, NULL, elname)
190 -#define EXT4_RW_ATTR_SBI_UI(name, elname)      \
191 -       EXT4_ATTR_OFFSET(name, 0644, sbi_ui_show, sbi_ui_store, elname)
192 +#define EXT4_RW_ATTR_SBI_UI(_name,_elname)     \
193 +       EXT4_ATTR_OFFSET(_name, 0644, pointer_ui, ext4_sb_info, _elname)
195 -#define ATTR_LIST(name) &ext4_attr_##name.attr
196 -#define EXT4_DEPRECATED_ATTR(_name, _val)      \
197 +#define EXT4_ATTR_PTR(_name,_mode,_id,_ptr) \
198  static struct ext4_attr ext4_attr_##_name = {                  \
199 -       .attr = {.name = __stringify(_name), .mode = 0444 },    \
200 -       .show   = sbi_deprecated_show,                          \
201 +       .attr = {.name = __stringify(_name), .mode = _mode },   \
202 +       .attr_id = attr_##_id,                                  \
203 +       .attr_ptr = ptr_explicit,                               \
204         .u = {                                                  \
205 -               .deprecated_val = _val,                         \
206 +               .explicit_ptr = _ptr,                           \
207         },                                                      \
210 -EXT4_RO_ATTR(delayed_allocation_blocks);
211 -EXT4_RO_ATTR(session_write_kbytes);
212 -EXT4_RO_ATTR(lifetime_write_kbytes);
213 -EXT4_RW_ATTR(reserved_clusters);
214 -EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, sbi_ui_show,
215 -                inode_readahead_blks_store, s_inode_readahead_blks);
216 +#define ATTR_LIST(name) &ext4_attr_##name.attr
218 +EXT4_ATTR_FUNC(delayed_allocation_blocks, 0444);
219 +EXT4_ATTR_FUNC(session_write_kbytes, 0444);
220 +EXT4_ATTR_FUNC(lifetime_write_kbytes, 0444);
221 +EXT4_ATTR_FUNC(reserved_clusters, 0644);
223 +EXT4_ATTR_OFFSET(inode_readahead_blks, 0644, inode_readahead,
224 +                ext4_sb_info, s_inode_readahead_blks);
225  EXT4_RW_ATTR_SBI_UI(inode_goal, s_inode_goal);
226  EXT4_RW_ATTR_SBI_UI(mb_stats, s_mb_stats);
227  EXT4_RW_ATTR_SBI_UI(mb_max_to_scan, s_mb_max_to_scan);
228 @@ -228,9 +176,8 @@ EXT4_RW_ATTR_SBI_UI(mb_min_to_scan, s_mb_min_to_scan);
229  EXT4_RW_ATTR_SBI_UI(mb_order2_req, s_mb_order2_reqs);
230  EXT4_RW_ATTR_SBI_UI(mb_stream_req, s_mb_stream_request);
231  EXT4_RW_ATTR_SBI_UI(mb_group_prealloc, s_mb_group_prealloc);
232 -EXT4_DEPRECATED_ATTR(max_writeback_mb_bump, 128);
233  EXT4_RW_ATTR_SBI_UI(extent_max_zeroout_kb, s_extent_max_zeroout_kb);
234 -EXT4_ATTR(trigger_fs_error, 0200, NULL, trigger_test_error);
235 +EXT4_ATTR(trigger_fs_error, 0200, trigger_test_error);
236  EXT4_RW_ATTR_SBI_UI(err_ratelimit_interval_ms, s_err_ratelimit_state.interval);
237  EXT4_RW_ATTR_SBI_UI(err_ratelimit_burst, s_err_ratelimit_state.burst);
238  EXT4_RW_ATTR_SBI_UI(warning_ratelimit_interval_ms, s_warning_ratelimit_state.interval);
239 @@ -241,6 +188,9 @@ EXT4_RO_ATTR_ES_UI(errors_count, s_error_count);
240  EXT4_RO_ATTR_ES_UI(first_error_time, s_first_error_time);
241  EXT4_RO_ATTR_ES_UI(last_error_time, s_last_error_time);
243 +static unsigned int old_bump_val = 128;
244 +EXT4_ATTR_PTR(max_writeback_mb_bump, 0444, pointer_ui, &old_bump_val);
246  static struct attribute *ext4_attrs[] = {
247         ATTR_LIST(delayed_allocation_blocks),
248         ATTR_LIST(session_write_kbytes),
249 @@ -270,10 +220,10 @@ static struct attribute *ext4_attrs[] = {
250  };
252  /* Features this copy of ext4 supports */
253 -EXT4_INFO_ATTR(lazy_itable_init);
254 -EXT4_INFO_ATTR(batched_discard);
255 -EXT4_INFO_ATTR(meta_bg_resize);
256 -EXT4_INFO_ATTR(encryption);
257 +EXT4_ATTR_FEATURE(lazy_itable_init);
258 +EXT4_ATTR_FEATURE(batched_discard);
259 +EXT4_ATTR_FEATURE(meta_bg_resize);
260 +EXT4_ATTR_FEATURE(encryption);
262  static struct attribute *ext4_feat_attrs[] = {
263         ATTR_LIST(lazy_itable_init),
264 @@ -283,14 +233,56 @@ static struct attribute *ext4_feat_attrs[] = {
265         NULL,
266  };
268 +static void *calc_ptr(struct ext4_attr *a, struct ext4_sb_info *sbi)
270 +       switch (a->attr_ptr) {
271 +       case ptr_explicit:
272 +               return a->u.explicit_ptr;
273 +       case ptr_ext4_sb_info_offset:
274 +               return (void *) (((char *) sbi) + a->u.offset);
275 +       case ptr_ext4_super_block_offset:
276 +               return (void *) (((char *) sbi->s_es) + a->u.offset);
277 +       }
278 +       return NULL;
281  static ssize_t ext4_attr_show(struct kobject *kobj,
282                               struct attribute *attr, char *buf)
284         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
285                                                 s_kobj);
286         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
287 +       void *ptr = calc_ptr(a, sbi);
289 +       switch (a->attr_id) {
290 +       case attr_delayed_allocation_blocks:
291 +               return snprintf(buf, PAGE_SIZE, "%llu\n",
292 +                               (s64) EXT4_C2B(sbi,
293 +                      percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
294 +       case attr_session_write_kbytes:
295 +               return session_write_kbytes_show(a, sbi, buf);
296 +       case attr_lifetime_write_kbytes:
297 +               return lifetime_write_kbytes_show(a, sbi, buf);
298 +       case attr_reserved_clusters:
299 +               return snprintf(buf, PAGE_SIZE, "%llu\n",
300 +                               (unsigned long long)
301 +                               atomic64_read(&sbi->s_resv_clusters));
302 +       case attr_inode_readahead:
303 +       case attr_pointer_ui:
304 +               if (!ptr)
305 +                       return 0;
306 +               return snprintf(buf, PAGE_SIZE, "%u\n",
307 +                               *((unsigned int *) ptr));
308 +       case attr_pointer_atomic:
309 +               if (!ptr)
310 +                       return 0;
311 +               return snprintf(buf, PAGE_SIZE, "%d\n",
312 +                               atomic_read((atomic_t *) ptr));
313 +       case attr_feature:
314 +               return snprintf(buf, PAGE_SIZE, "supported\n");
315 +       }
317 -       return a->show ? a->show(a, sbi, buf) : 0;
318 +       return 0;
321  static ssize_t ext4_attr_store(struct kobject *kobj,
322 @@ -300,8 +292,27 @@ static ssize_t ext4_attr_store(struct kobject *kobj,
323         struct ext4_sb_info *sbi = container_of(kobj, struct ext4_sb_info,
324                                                 s_kobj);
325         struct ext4_attr *a = container_of(attr, struct ext4_attr, attr);
326 +       void *ptr = calc_ptr(a, sbi);
327 +       unsigned long t;
328 +       int ret;
330 -       return a->store ? a->store(a, sbi, buf, len) : 0;
331 +       switch (a->attr_id) {
332 +       case attr_reserved_clusters:
333 +               return reserved_clusters_store(a, sbi, buf, len);
334 +       case attr_pointer_ui:
335 +               if (!ptr)
336 +                       return 0;
337 +               ret = kstrtoul(skip_spaces(buf), 0, &t);
338 +               if (ret)
339 +                       return ret;
340 +               *((unsigned int *) ptr) = t;
341 +               return len;
342 +       case attr_inode_readahead:
343 +               return inode_readahead_blks_store(a, sbi, buf, len);
344 +       case attr_trigger_test_error:
345 +               return trigger_test_error(a, sbi, buf, len);
346 +       }
347 +       return 0;
350  static void ext4_sb_release(struct kobject *kobj)
351 @@ -330,25 +341,9 @@ static struct kset ext4_kset = {
352         .kobj   = {.ktype = &ext4_ktype},
353  };
355 -static ssize_t ext4_feat_show(struct kobject *kobj,
356 -                             struct attribute *attr, char *buf)
358 -       return snprintf(buf, PAGE_SIZE, "supported\n");
362 - * We can not use ext4_attr_show/store because it relies on the kobject
363 - * being embedded in the ext4_sb_info structure which is definitely not
364 - * true in this case.
365 - */
366 -static const struct sysfs_ops ext4_feat_ops = {
367 -       .show   = ext4_feat_show,
368 -       .store  = NULL,
371  static struct kobj_type ext4_feat_ktype = {
372         .default_attrs  = ext4_feat_attrs,
373 -       .sysfs_ops      = &ext4_feat_ops,
374 +       .sysfs_ops      = &ext4_attr_ops,
375  };
377  static struct kobject ext4_feat = {