Signed-off-by: Gao Xiang <[email protected]>
---
fs/erofs/internal.h | 60 ++++++++++++++++++++++++++++++++++++++++++++
fs/erofs/super.c | 12 +++++++++
fs/erofs/utils.c | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 143 insertions(+)
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index e202ef3..489cd4e 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -80,6 +80,14 @@ struct erofs_sb_info {
#ifdef CONFIG_EROFS_FS_ZIP
/* cluster size in bit shift */
unsigned char clusterbits;
+
+ /* the dedicated workstation for compression */
+ struct {
+ struct radix_tree_root tree;
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 17, 0))
+ spinlock_t lock;
+#endif
+ } workstn;
#endif
u32 build_time_nsec;
@@ -150,6 +158,58 @@ static inline void *erofs_kmalloc(struct erofs_sb_info
*sbi,
#define set_opt(sbi, option) ((sbi)->mount_opt |= EROFS_MOUNT_##option)
#define test_opt(sbi, option) ((sbi)->mount_opt & EROFS_MOUNT_##option)
+#ifdef CONFIG_EROFS_FS_ZIP
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 17, 0))
+#define erofs_workstn_lock(sbi) spin_lock(&(sbi)->workstn.lock)
+#define erofs_workstn_unlock(sbi) spin_unlock(&(sbi)->workstn.lock)
+#else
+#define erofs_workstn_lock(sbi) xa_lock(&(sbi)->workstn.tree)
+#define erofs_workstn_unlock(sbi) xa_unlock(&(sbi)->workstn.tree)
+#endif
+
+/* basic unit of the workstation of a super_block */
+struct erofs_workgroup {
+ /* the workgroup index in the workstation */
+ pgoff_t index;
+
+ /* overall workgroup reference count */
+ atomic_t refcount;
+};
+
+static inline bool erofs_workgroup_get(struct erofs_workgroup *grp)
+{
+ int o;
+
+repeat:
+ o = atomic_read(&grp->refcount);
+
+ if (unlikely(o <= 0))
+ return -1;
+
+ if (unlikely(atomic_cmpxchg(&grp->refcount, o, o + 1) != o))
+ goto repeat;
+
+ return 0;
+}
+
+#define __erofs_workgroup_get(grp) atomic_inc(&(grp)->refcount)
+
+extern struct erofs_workgroup *erofs_find_workgroup(
+ struct super_block *sb, pgoff_t index, bool *tag);
+
+extern int erofs_register_workgroup(struct super_block *sb,
+ struct erofs_workgroup *grp, bool tag);
+
+extern unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
+ unsigned long nr_shrink, bool cleanup);
+
+static inline void erofs_workstation_cleanup_all(struct super_block *sb)
+{
+ erofs_shrink_workstation(EROFS_SB(sb), ~0UL, true);
+}
+
+#endif
+
/* we strictly follow PAGE_SIZE and no buffer head */
#define LOG_BLOCK_SIZE PAGE_SHIFT
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 9452a89..d26eeed 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -285,6 +285,13 @@ static int erofs_read_super(struct super_block *sb,
if (!silent)
infoln("root inode @ nid %llu", ROOT_NID(sbi));
+#ifdef CONFIG_EROFS_FS_ZIP
+ INIT_RADIX_TREE(&sbi->workstn.tree, GFP_ATOMIC);
+#if (LINUX_VERSION_CODE < KERNEL_VERSION(4, 17, 0))
+ spin_lock_init(&sbi->workstn.lock);
+#endif
+#endif
+
/* get the root inode */
inode = erofs_iget(sb, ROOT_NID(sbi), true);
if (IS_ERR(inode)) {
@@ -355,6 +362,11 @@ static void erofs_put_super(struct super_block *sb)
__putname(sbi->dev_name);
mutex_lock(&sbi->umount_mutex);
+
+#ifdef CONFIG_EROFS_FS_ZIP
+ erofs_workstation_cleanup_all(sb);
+#endif
+
erofs_unregister_super(sb);
mutex_unlock(&sbi->umount_mutex);
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
index 6b8c60d..912be2a 100644
--- a/fs/erofs/utils.c
+++ b/fs/erofs/utils.c
@@ -29,6 +29,76 @@ struct page *erofs_allocpage(struct list_head *pool, gfp_t
gfp)
return page;
}
+/* global shrink count (for all mounted EROFS instances) */
+static atomic_long_t erofs_global_shrink_cnt;
+
+#ifdef CONFIG_EROFS_FS_ZIP
+
+/* radix_tree and the future XArray both don't use tagptr_t yet */
+struct erofs_workgroup *erofs_find_workgroup(
+ struct super_block *sb, pgoff_t index, bool *tag)
+{
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
+ struct erofs_workgroup *grp;
+
+repeat:
+ rcu_read_lock();
+ grp = radix_tree_lookup(&sbi->workstn.tree, index);
+ if (grp != NULL) {
+ *tag = radix_tree_exceptional_entry(grp);
+ grp = (void *)((unsigned long)grp &
+ ~RADIX_TREE_EXCEPTIONAL_ENTRY);
+
+ if (erofs_workgroup_get(grp)) {
+ /* prefer to relax rcu read side */
+ rcu_read_unlock();
+ goto repeat;
+ }
+
+ BUG_ON(index != grp->index);
+ }
+ rcu_read_unlock();
+ return grp;
+}
+
+int erofs_register_workgroup(struct super_block *sb,
+ struct erofs_workgroup *grp,
+ bool tag)
+{
+ struct erofs_sb_info *sbi;
+ int err = radix_tree_preload(GFP_NOFS);
+
+ if (err)
+ return err;
+
+ sbi = EROFS_SB(sb);
+ erofs_workstn_lock(sbi);
+
+ if (tag)
+ grp = (void *)((unsigned long)grp |
+ 1UL << RADIX_TREE_EXCEPTIONAL_SHIFT);
+
+ err = radix_tree_insert(&sbi->workstn.tree,
+ grp->index, grp);
+
+ if (!err) {
+ __erofs_workgroup_get(grp);
+ atomic_long_inc(&erofs_global_shrink_cnt);
+ }
+
+ erofs_workstn_unlock(sbi);
+ radix_tree_preload_end();
+ return err;
+}
+
+unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
+ unsigned long nr_shrink,
+ bool cleanup)
+{
+ return 0;
+}
+
+#endif
/* protected by 'erofs_sb_list_lock' */
static unsigned int shrinker_run_no;
@@ -108,6 +178,7 @@ unsigned long erofs_shrink_scan(struct shrinker *shrink,
list_move_tail(&sbi->list, &erofs_sb_list);
mutex_unlock(&sbi->umount_mutex);
+ freed += erofs_shrink_workstation(sbi, nr, false);
if (freed >= nr)
break;
}
--
1.9.1
