ext4: move procfs registration code to fs/ext4/sysfs.c

This allows us to refactor the procfs code, which saves a bit of
compiled space.  More importantly it isolates most of the procfs
support code into a single file, so it's easier to #ifdef it out if
the proc file system has been disabled.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>

6 files changed, 77 insertions, 106 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 76daccf38aa3..766b7f7b782b 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2245,6 +2245,7 @@ extern int ext4_init_inode_table(struct super_block *sb,
 extern void ext4_end_bitmap_read(struct buffer_head *bh, int uptodate);
 
 /* mballoc.c */
+extern const struct file_operations ext4_seq_mb_groups_fops;
 extern long ext4_mb_stats;
 extern long ext4_mb_max_to_scan;
 extern int ext4_mb_init(struct super_block *);
@@ -2372,6 +2373,7 @@ extern int ext4_group_extend(struct super_block *sb,
 extern int ext4_resize_fs(struct super_block *sb, ext4_fsblk_t n_blocks_count);
 
 /* super.c */
+extern int ext4_seq_options_show(struct seq_file *seq, void *offset);
 extern int ext4_calculate_overhead(struct super_block *sb);
 extern void ext4_superblock_csum_set(struct super_block *sb);
 extern void *ext4_kvmalloc(size_t size, gfp_t flags);
@@ -2905,6 +2907,7 @@ extern const struct inode_operations ext4_fast_symlink_inode_operations;
 
 /* sysfs.c */
 extern int ext4_register_sysfs(struct super_block *sb);
+extern void ext4_unregister_sysfs(struct super_block *sb);
 extern int __init ext4_init_sysfs(void);
 extern void ext4_exit_sysfs(void);
 
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c
index 26724aeece73..ac748b3af1c1 100644
--- a/fs/ext4/extents_status.c
+++ b/fs/ext4/extents_status.c
@@ -1089,20 +1089,9 @@ static unsigned long ext4_es_scan(struct shrinker *shrink,
         return nr_shrunk;
 }
 
-static void *ext4_es_seq_shrinker_info_start(struct seq_file *seq, loff_t *pos)
+int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v)
 {
-        return *pos ? NULL : SEQ_START_TOKEN;
-}
-
-static void *
-ext4_es_seq_shrinker_info_next(struct seq_file *seq, void *v, loff_t *pos)
-{
-        return NULL;
-}
-
-static int ext4_es_seq_shrinker_info_show(struct seq_file *seq, void *v)
-{
-        struct ext4_sb_info *sbi = seq->private;
+        struct ext4_sb_info *sbi = EXT4_SB((struct super_block *) seq->private);
         struct ext4_es_stats *es_stats = &sbi->s_es_stats;
         struct ext4_inode_info *ei, *max = NULL;
         unsigned int inode_cnt = 0;
@@ -1143,45 +1132,6 @@ static int ext4_es_seq_shrinker_info_show(struct seq_file *seq, void *v)
         return 0;
 }
 
-static void ext4_es_seq_shrinker_info_stop(struct seq_file *seq, void *v)
-{
-}
-
-static const struct seq_operations ext4_es_seq_shrinker_info_ops = {
-        .start = ext4_es_seq_shrinker_info_start,
-        .next  = ext4_es_seq_shrinker_info_next,
-        .stop  = ext4_es_seq_shrinker_info_stop,
-        .show  = ext4_es_seq_shrinker_info_show,
-};
-
-static int
-ext4_es_seq_shrinker_info_open(struct inode *inode, struct file *file)
-{
-        int ret;
-
-        ret = seq_open(file, &ext4_es_seq_shrinker_info_ops);
-        if (!ret) {
-                struct seq_file *m = file->private_data;
-                m->private = PDE_DATA(inode);
-        }
-
-        return ret;
-}
-
-static int
-ext4_es_seq_shrinker_info_release(struct inode *inode, struct file *file)
-{
-        return seq_release(inode, file);
-}
-
-static const struct file_operations ext4_es_seq_shrinker_info_fops = {
-        .owner          = THIS_MODULE,
-        .open           = ext4_es_seq_shrinker_info_open,
-        .read           = seq_read,
-        .llseek         = seq_lseek,
-        .release        = ext4_es_seq_shrinker_info_release,
-};
-
 int ext4_es_register_shrinker(struct ext4_sb_info *sbi)
 {
         int err;
@@ -1210,10 +1160,6 @@ int ext4_es_register_shrinker(struct ext4_sb_info *sbi)
         if (err)
                 goto err2;
 
-        if (sbi->s_proc)
-                proc_create_data("es_shrinker_info", S_IRUGO, sbi->s_proc,
-                                 &ext4_es_seq_shrinker_info_fops, sbi);
-
         return 0;
 
 err2:
@@ -1225,8 +1171,6 @@ err1:
 
 void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi)
 {
-        if (sbi->s_proc)
-                remove_proc_entry("es_shrinker_info", sbi->s_proc);
         percpu_counter_destroy(&sbi->s_es_stats.es_stats_all_cnt);
         percpu_counter_destroy(&sbi->s_es_stats.es_stats_shk_cnt);
         unregister_shrinker(&sbi->s_es_shrinker);
diff --git a/fs/ext4/extents_status.h b/fs/ext4/extents_status.h
index 691b52613ce4..f7aa24f4642d 100644
--- a/fs/ext4/extents_status.h
+++ b/fs/ext4/extents_status.h
@@ -172,4 +172,6 @@ static inline void ext4_es_store_pblock_status(struct extent_status *es,
 extern int ext4_es_register_shrinker(struct ext4_sb_info *sbi);
 extern void ext4_es_unregister_shrinker(struct ext4_sb_info *sbi);
 
+extern int ext4_seq_es_shrinker_info_show(struct seq_file *seq, void *v);
+
 #endif /* _EXT4_EXTENTS_STATUS_H */
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 34b610ea5030..b0f7ee57630b 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -2333,7 +2333,7 @@ static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file)
 
 }
 
-static const struct file_operations ext4_mb_seq_groups_fops = {
+const struct file_operations ext4_seq_mb_groups_fops = {
         .owner          = THIS_MODULE,
         .open           = ext4_mb_seq_groups_open,
         .read           = seq_read,
@@ -2661,10 +2661,6 @@ int ext4_mb_init(struct super_block *sb)
         if (ret != 0)
                 goto out_free_locality_groups;
 
-        if (sbi->s_proc)
-                proc_create_data("mb_groups", S_IRUGO, sbi->s_proc,
-                                 &ext4_mb_seq_groups_fops, sb);
-
         return 0;
 
 out_free_locality_groups:
@@ -2705,9 +2701,6 @@ int ext4_mb_release(struct super_block *sb)
         struct ext4_sb_info *sbi = EXT4_SB(sb);
         struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits);
 
-        if (sbi->s_proc)
-                remove_proc_entry("mb_groups", sbi->s_proc);
-
         if (sbi->s_group_info) {
                 for (i = 0; i < ngroups; i++) {
                         grinfo = ext4_get_group_info(sb, i);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 4a574fbeffec..7ef3fa58d3fe 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -34,7 +34,6 @@
 #include <linux/namei.h>
 #include <linux/quotaops.h>
 #include <linux/seq_file.h>
-#include <linux/proc_fs.h>
 #include <linux/ctype.h>
 #include <linux/log2.h>
 #include <linux/crc16.h>
@@ -54,7 +53,6 @@
 #define CREATE_TRACE_POINTS
 #include <trace/events/ext4.h>
 
-static struct proc_dir_entry *ext4_proc_root;
 static struct ext4_lazy_init *ext4_li_info;
 static struct mutex ext4_li_mtx;
 static int ext4_mballoc_ready;
@@ -797,6 +795,7 @@ static void ext4_put_super(struct super_block *sb)
                         ext4_abort(sb, "Couldn't clean up the journal");
         }
 
+        ext4_unregister_sysfs(sb);
         ext4_es_unregister_shrinker(sbi);
         del_timer_sync(&sbi->s_err_report);
         ext4_release_system_zone(sb);
@@ -811,12 +810,6 @@ static void ext4_put_super(struct super_block *sb)
         if (!(sb->s_flags & MS_RDONLY))
                 ext4_commit_super(sb, 1);
 
-        if (sbi->s_proc) {
-                remove_proc_entry("options", sbi->s_proc);
-                remove_proc_entry(sb->s_id, ext4_proc_root);
-        }
-        kobject_del(&sbi->s_kobj);
-
         for (i = 0; i < sbi->s_gdb_count; i++)
                 brelse(sbi->s_group_desc[i]);
         kvfree(sbi->s_group_desc);
@@ -1877,7 +1870,7 @@ static int ext4_show_options(struct seq_file *seq, struct dentry *root)
         return _ext4_show_options(seq, root->d_sb, 0);
 }
 
-static int options_seq_show(struct seq_file *seq, void *offset)
+int ext4_seq_options_show(struct seq_file *seq, void *offset)
 {
         struct super_block *sb = seq->private;
         int rc;
@@ -1888,19 +1881,6 @@ static int options_seq_show(struct seq_file *seq, void *offset)
         return rc;
 }
 
-static int options_open_fs(struct inode *inode, struct file *file)
-{
-        return single_open(file, options_seq_show, PDE_DATA(inode));
-}
-
-static const struct file_operations ext4_seq_options_fops = {
-        .owner = THIS_MODULE,
-        .open = options_open_fs,
-        .read = seq_read,
-        .llseek = seq_lseek,
-        .release = single_release,
-};
-
 static int ext4_setup_super(struct super_block *sb, struct ext4_super_block *es,
                             int read_only)
 {
@@ -3616,13 +3596,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
                 goto failed_mount;
         }
 
-        if (ext4_proc_root)
-                sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
-
-        if (sbi->s_proc)
-                proc_create_data("options", S_IRUGO, sbi->s_proc,
-                                 &ext4_seq_options_fops, sb);
-
         bgl_lock_init(sbi->s_blockgroup_lock);
 
         for (i = 0; i < db_count; i++) {
@@ -3960,7 +3933,7 @@ cantfind_ext4:
 
 #ifdef CONFIG_QUOTA
 failed_mount8:
-        kobject_del(&sbi->s_kobj);
+        ext4_unregister_sysfs(sb);
 #endif
 failed_mount7:
         ext4_unregister_li_request(sb);
@@ -4000,10 +3973,6 @@ failed_mount2:
 failed_mount:
         if (sbi->s_chksum_driver)
                 crypto_free_shash(sbi->s_chksum_driver);
-        if (sbi->s_proc) {
-                remove_proc_entry("options", sbi->s_proc);
-                remove_proc_entry(sb->s_id, ext4_proc_root);
-        }
 #ifdef CONFIG_QUOTA
         for (i = 0; i < EXT4_MAXQUOTAS; i++)
                 kfree(sbi->s_qf_names[i]);
@@ -5264,7 +5233,6 @@ static int __init ext4_init_fs(void)
         err = ext4_init_system_zone();
         if (err)
                 goto out4;
-        ext4_proc_root = proc_mkdir("fs/ext4", NULL);
 
         err = ext4_init_sysfs();
         if (err)
@@ -5295,8 +5263,6 @@ out1:
 out2:
         ext4_exit_sysfs();
 out3:
-        if (ext4_proc_root)
-                remove_proc_entry("fs/ext4", NULL);
         ext4_exit_system_zone();
 out4:
         ext4_exit_pageio();
@@ -5316,7 +5282,6 @@ static void __exit ext4_exit_fs(void)
         destroy_inodecache();
         ext4_exit_mballoc();
         ext4_exit_sysfs();
-        remove_proc_entry("fs/ext4", NULL);
         ext4_exit_system_zone();
         ext4_exit_pageio();
         ext4_exit_es();
diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c
index 87ac08964683..62bef0f06421 100644
--- a/fs/ext4/sysfs.c
+++ b/fs/ext4/sysfs.c
@@ -34,6 +34,9 @@ typedef enum {
         ptr_ext4_super_block_offset,
 } attr_ptr_t;
 
+static const char *proc_dirname = "fs/ext4";
+static struct proc_dir_entry *ext4_proc_root;
+
 struct ext4_attr {
         struct attribute attr;
         short attr_id;
@@ -347,14 +350,71 @@ static struct kobject ext4_feat = {
         .kset   = &ext4_kset,
 };
 
+#define PROC_FILE_SHOW_DEFN(name) \
+static int name##_open(struct inode *inode, struct file *file) \
+{ \
+        return single_open(file, ext4_seq_##name##_show, PDE_DATA(inode)); \
+} \
+\
+const struct file_operations ext4_seq_##name##_fops = { \
+        .owner          = THIS_MODULE, \
+        .open           = name##_open, \
+        .read           = seq_read, \
+        .llseek         = seq_lseek, \
+        .release        = single_release, \
+}
+
+#define PROC_FILE_LIST(name) \
+        { __stringify(name), &ext4_seq_##name##_fops }
+
+PROC_FILE_SHOW_DEFN(es_shrinker_info);
+PROC_FILE_SHOW_DEFN(options);
+
+static struct ext4_proc_files {
+        const char *name;
+        const struct file_operations *fops;
+} proc_files[] = {
+        PROC_FILE_LIST(options),
+        PROC_FILE_LIST(es_shrinker_info),
+        PROC_FILE_LIST(mb_groups),
+        { NULL, NULL },
+};
+
 int ext4_register_sysfs(struct super_block *sb)
 {
         struct ext4_sb_info *sbi = EXT4_SB(sb);
+        struct ext4_proc_files *p;
+        int err;
 
         sbi->s_kobj.kset = &ext4_kset;
         init_completion(&sbi->s_kobj_unregister);
-        return kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL,
-                                    "%s", sb->s_id);
+        err = kobject_init_and_add(&sbi->s_kobj, &ext4_sb_ktype, NULL,
+                                   "%s", sb->s_id);
+        if (err)
+                return err;
+
+        if (ext4_proc_root)
+                sbi->s_proc = proc_mkdir(sb->s_id, ext4_proc_root);
+
+        if (sbi->s_proc) {
+                for (p = proc_files; p->name; p++)
+                        proc_create_data(p->name, S_IRUGO, sbi->s_proc,
+                                         p->fops, sb);
+        }
+        return 0;
+}
+
+void ext4_unregister_sysfs(struct super_block *sb)
+{
+        struct ext4_sb_info *sbi = EXT4_SB(sb);
+        struct ext4_proc_files *p;
+
+        if (sbi->s_proc) {
+                for (p = proc_files; p->name; p++)
+                        remove_proc_entry(p->name, sbi->s_proc);
+                remove_proc_entry(sb->s_id, ext4_proc_root);
+        }
+        kobject_del(&sbi->s_kobj);
 }
 
 int __init ext4_init_sysfs(void)
@@ -371,6 +431,8 @@ int __init ext4_init_sysfs(void)
                                    NULL, "features");
         if (ret)
                 kset_unregister(&ext4_kset);
+        else
+                ext4_proc_root = proc_mkdir(proc_dirname, NULL);
         return ret;
 }
 
@@ -378,5 +440,7 @@ void ext4_exit_sysfs(void)
 {
         kobject_put(&ext4_feat);
         kset_unregister(&ext4_kset);
+        remove_proc_entry(proc_dirname, NULL);
+        ext4_proc_root = NULL;
 }