[PATCH] (2/2) fs/super.c cleanups

kill_super() and deactivate_super() merged.

Next step will be to export these suckers - after that we will be finally
done with infrastructure for filesystems with nontrivial ->get_sb().

diff --git a/fs/namespace.c b/fs/namespace.c
index aa6cb6b8f35895468df20b1485e3ba71bcdf9838..1225bac1bafa4916c870a01caaa376c81fe9e520 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -23,7 +23,6 @@
 
 struct vfsmount *do_kern_mount(const char *type, int flags, char *name, void *data);
 int do_remount_sb(struct super_block *sb, int flags, void * data);
-void kill_super(struct super_block *sb);
 int __init init_rootfs(void);
 
 static struct list_head *mount_hashtable;
@@ -152,7 +151,7 @@ void __mntput(struct vfsmount *mnt)
        struct super_block *sb = mnt->mnt_sb;
        dput(mnt->mnt_root);
        free_vfsmnt(mnt);
-       kill_super(sb);
+       deactivate_super(sb);
 }
 
 /* iterator */

diff --git a/fs/super.c b/fs/super.c
index dc1ced9f665b4f4176101dd0a120a4b5fa58477b..66a6274d1b718dddcf84f3bf324c9e49f65adfd8 100644 (file)
--- a/fs/super.c
+++ b/fs/super.c
@@ -296,22 +296,6 @@ static inline void destroy_super(struct super_block *s)
 
 /* Superblock refcounting  */
 
-/**
- *     deactivate_super        -       turn an active reference into temporary
- *     @s: superblock to deactivate
- *
- *     Turns an active reference into temporary one.  Returns 0 if there are
- *     other active references, 1 if we had deactivated the last one.
- */
-static inline int deactivate_super(struct super_block *s)
-{
-       if (!atomic_dec_and_lock(&s->s_active, &sb_lock))
-               return 0;
-       s->s_count -= S_BIAS-1;
-       spin_unlock(&sb_lock);
-       return 1;
-}
-
 /**
  *     put_super       -       drop a temporary reference to superblock
  *     @s: superblock in question
@@ -327,6 +311,28 @@ static inline void put_super(struct super_block *s)
        spin_unlock(&sb_lock);
 }
 
+/**
+ *     deactivate_super        -       drop an active reference to superblock
+ *     @s: superblock to deactivate
+ *
+ *     Drops an active reference to superblock, acquiring a temprory one if
+ *     there is no active references left.  In that case we lock superblock,
+ *     tell fs driver to shut it down and drop the temporary reference we
+ *     had just acquired.
+ */
+void deactivate_super(struct super_block *s)
+{
+       struct file_system_type *fs = s->s_type;
+       if (atomic_dec_and_lock(&s->s_active, &sb_lock)) {
+               s->s_count -= S_BIAS-1;
+               spin_unlock(&sb_lock);
+               down_write(&s->s_umount);
+               fs->kill_sb(s);
+               put_filesystem(fs);
+               put_super(s);
+       }
+}
+
 /**
  *     grab_super      - acquire an active reference
  *     @s      - reference we are trying to make active
@@ -380,13 +386,12 @@ static void insert_super(struct super_block *s, struct file_system_type *type)
  *     remove_super    -       makes superblock unreachable
  *     @s:     superblock in question
  *
- *     Removes superblock from the lists, unlocks it and drop the reference
- *     @s should have no active references by that time and after
- *     remove_super() it's essentially in rundown mode - all remaining
- *     references are temporary, no new reference of any sort are going
- *     to appear and all holders of temporary ones will eventually drop them.
- *     At that point superblock itself will be destroyed; all its contents
- *     is already gone.
+ *     Removes superblock from the lists, and unlocks it.  @s should have
+ *     no active references by that time and after remove_super() it's
+ *     essentially in rundown mode - all remaining references are temporary,
+ *     no new references of any sort are going to appear and all holders
+ *     of temporary ones will eventually drop them.  At that point superblock
+ *     itself will be destroyed; all its contents is already gone.
  */
 static void remove_super(struct super_block *s)
 {
@@ -395,7 +400,6 @@ static void remove_super(struct super_block *s)
        list_del(&s->s_instances);
        spin_unlock(&sb_lock);
        up_write(&s->s_umount);
-       put_super(s);
 }
 
 static void generic_shutdown_super(struct super_block *sb)
@@ -432,18 +436,6 @@ static void generic_shutdown_super(struct super_block *sb)
        remove_super(sb);
 }
 
-void kill_super(struct super_block *sb)
-{
-       struct file_system_type *fs = sb->s_type;
-
-       if (!deactivate_super(sb))
-               return;
-
-       down_write(&sb->s_umount);
-       fs->kill_sb(sb);
-       put_filesystem(fs);
-}
-
 struct super_block *sget(struct file_system_type *type,
                        int (*test)(struct super_block *,void *),
                        int (*set)(struct super_block *,void *),
@@ -732,7 +724,7 @@ struct super_block *get_sb_bdev(struct file_system_type *fs_type,
        if (s->s_root) {
                if ((flags ^ s->s_flags) & MS_RDONLY) {
                        up_write(&s->s_umount);
-                       kill_super(s);
+                       deactivate_super(s);
                        s = ERR_PTR(-EBUSY);
                }
                bd_release(bdev);
@@ -743,7 +735,7 @@ struct super_block *get_sb_bdev(struct file_system_type *fs_type,
                error = fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
                if (error) {
                        up_write(&s->s_umount);
-                       kill_super(s);
+                       deactivate_super(s);
                        s = ERR_PTR(error);
                } else
                        s->s_flags |= MS_ACTIVE;
@@ -781,7 +773,7 @@ struct super_block *get_sb_nodev(struct file_system_type *fs_type,
        error = fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
        if (error) {
                up_write(&s->s_umount);
-               kill_super(s);
+               deactivate_super(s);
                return ERR_PTR(error);
        }
        s->s_flags |= MS_ACTIVE;
@@ -807,7 +799,7 @@ struct super_block *get_sb_single(struct file_system_type *fs_type,
                error = fill_super(s, data, flags & MS_VERBOSE ? 1 : 0);
                if (error) {
                        up_write(&s->s_umount);
-                       kill_super(s);
+                       deactivate_super(s);
                        return ERR_PTR(error);
                }
                s->s_flags |= MS_ACTIVE;

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 6ff5a4b41490ca0a1c540858f1ae2e0b9cdcd931..d4041b23a55c2786c8f28b02c4d42ac91e54f458 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -959,6 +959,7 @@ struct super_block *get_sb_nodev(struct file_system_type *fs_type,
 void kill_block_super(struct super_block *sb);
 void kill_anon_super(struct super_block *sb);
 void kill_litter_super(struct super_block *sb);
+void deactivate_super(struct super_block *sb);
 
 /* Alas, no aliases. Too much hassle with bringing module.h everywhere */
 #define fops_get(fops) \

diff --git a/kernel/ksyms.c b/kernel/ksyms.c
index fef69bf4e32db3c63198c359945c52c026d3e960..2b6993b9c66c15311ccbea54f3f8d06a40da3221 100644 (file)
--- a/kernel/ksyms.c
+++ b/kernel/ksyms.c
@@ -291,6 +291,7 @@ EXPORT_SYMBOL(get_sb_nodev);
 EXPORT_SYMBOL(get_sb_single);
 EXPORT_SYMBOL(kill_anon_super);
 EXPORT_SYMBOL(kill_litter_super);
+EXPORT_SYMBOL(deactivate_super);
 
 /* for stackable file systems (lofs, wrapfs, cryptfs, etc.) */
 EXPORT_SYMBOL(default_llseek);