This is a note to let you know that I've just added the patch titled
erofs: move erofs_workgroup operations into zdata.c
to the 6.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
erofs-move-erofs_workgroup-operations-into-zdata.c.patch
and it can be found in the queue-6.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit fc1452d3efd6434e6c9f9b4ad5215fcbbf64daa2
Author: Gao Xiang <xiang@xxxxxxxxxx>
Date: Mon Oct 21 11:53:22 2024 +0800
erofs: move erofs_workgroup operations into zdata.c
[ Upstream commit 9c91f959626e6d9f460b8906e27c37fca1b6456a ]
Move related helpers into zdata.c as an intermediate step of getting
rid of `struct erofs_workgroup`, and rename:
erofs_workgroup_put => z_erofs_put_pcluster
erofs_workgroup_get => z_erofs_get_pcluster
erofs_try_to_release_workgroup => erofs_try_to_release_pcluster
erofs_shrink_workstation => z_erofs_shrink_scan
Reviewed-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20241021035323.3280682-2-hsiangkao@xxxxxxxxxxxxxxxxx
Stable-dep-of: db902986dee4 ("erofs: fix potential return value overflow of z_erofs_shrink_scan()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index b9649e3b2dd56..5fbc76b65f5c3 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -452,17 +452,15 @@ static inline void erofs_pagepool_add(struct page **pagepool, struct page *page)
void erofs_release_pages(struct page **pagepool);
#ifdef CONFIG_EROFS_FS_ZIP
-void erofs_workgroup_put(struct erofs_workgroup *grp);
-bool erofs_workgroup_get(struct erofs_workgroup *grp);
-void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
+extern atomic_long_t erofs_global_shrink_cnt;
void erofs_shrinker_register(struct super_block *sb);
void erofs_shrinker_unregister(struct super_block *sb);
int __init erofs_init_shrinker(void);
void erofs_exit_shrinker(void);
int __init z_erofs_init_subsystem(void);
void z_erofs_exit_subsystem(void);
-int erofs_try_to_free_all_cached_folios(struct erofs_sb_info *sbi,
- struct erofs_workgroup *egrp);
+unsigned long z_erofs_shrink_scan(struct erofs_sb_info *sbi,
+ unsigned long nr_shrink);
int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map,
int flags);
void *z_erofs_get_gbuf(unsigned int requiredpages);
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 8c6082fc86b29..d2235f2a0acdc 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -587,8 +587,8 @@ static void z_erofs_bind_cache(struct z_erofs_decompress_frontend *fe)
}
/* (erofs_shrinker) disconnect cached encoded data with pclusters */
-int erofs_try_to_free_all_cached_folios(struct erofs_sb_info *sbi,
- struct erofs_workgroup *grp)
+static int erofs_try_to_free_all_cached_folios(struct erofs_sb_info *sbi,
+ struct erofs_workgroup *grp)
{
struct z_erofs_pcluster *const pcl =
container_of(grp, struct z_erofs_pcluster, obj);
@@ -710,6 +710,23 @@ static int z_erofs_attach_page(struct z_erofs_decompress_frontend *fe,
return ret;
}
+static bool z_erofs_get_pcluster(struct erofs_workgroup *grp)
+{
+ if (lockref_get_not_zero(&grp->lockref))
+ return true;
+
+ spin_lock(&grp->lockref.lock);
+ if (__lockref_is_dead(&grp->lockref)) {
+ spin_unlock(&grp->lockref.lock);
+ return false;
+ }
+
+ if (!grp->lockref.count++)
+ atomic_long_dec(&erofs_global_shrink_cnt);
+ spin_unlock(&grp->lockref.lock);
+ return true;
+}
+
static int z_erofs_register_pcluster(struct z_erofs_decompress_frontend *fe)
{
struct erofs_map_blocks *map = &fe->map;
@@ -757,7 +774,7 @@ static int z_erofs_register_pcluster(struct z_erofs_decompress_frontend *fe)
xa_lock(&sbi->managed_pslots);
pre = __xa_cmpxchg(&sbi->managed_pslots, grp->index,
NULL, grp, GFP_KERNEL);
- if (!pre || xa_is_err(pre) || erofs_workgroup_get(pre)) {
+ if (!pre || xa_is_err(pre) || z_erofs_get_pcluster(pre)) {
xa_unlock(&sbi->managed_pslots);
break;
}
@@ -801,7 +818,7 @@ static int z_erofs_pcluster_begin(struct z_erofs_decompress_frontend *fe)
while (1) {
rcu_read_lock();
grp = xa_load(&EROFS_SB(sb)->managed_pslots, blknr);
- if (!grp || erofs_workgroup_get(grp)) {
+ if (!grp || z_erofs_get_pcluster(grp)) {
DBG_BUGON(grp && blknr != grp->index);
rcu_read_unlock();
break;
@@ -869,7 +886,7 @@ static void z_erofs_rcu_callback(struct rcu_head *head)
struct z_erofs_pcluster, rcu));
}
-void erofs_workgroup_free_rcu(struct erofs_workgroup *grp)
+static void erofs_workgroup_free_rcu(struct erofs_workgroup *grp)
{
struct z_erofs_pcluster *const pcl =
container_of(grp, struct z_erofs_pcluster, obj);
@@ -877,6 +894,77 @@ void erofs_workgroup_free_rcu(struct erofs_workgroup *grp)
call_rcu(&pcl->rcu, z_erofs_rcu_callback);
}
+static bool erofs_try_to_release_pcluster(struct erofs_sb_info *sbi,
+ struct erofs_workgroup *grp)
+{
+ int free = false;
+
+ spin_lock(&grp->lockref.lock);
+ if (grp->lockref.count)
+ goto out;
+
+ /*
+ * Note that all cached folios should be detached before deleted from
+ * the XArray. Otherwise some folios could be still attached to the
+ * orphan old pcluster when the new one is available in the tree.
+ */
+ if (erofs_try_to_free_all_cached_folios(sbi, grp))
+ goto out;
+
+ /*
+ * It's impossible to fail after the pcluster is freezed, but in order
+ * to avoid some race conditions, add a DBG_BUGON to observe this.
+ */
+ DBG_BUGON(__xa_erase(&sbi->managed_pslots, grp->index) != grp);
+
+ lockref_mark_dead(&grp->lockref);
+ free = true;
+out:
+ spin_unlock(&grp->lockref.lock);
+ if (free) {
+ atomic_long_dec(&erofs_global_shrink_cnt);
+ erofs_workgroup_free_rcu(grp);
+ }
+ return free;
+}
+
+unsigned long z_erofs_shrink_scan(struct erofs_sb_info *sbi,
+ unsigned long nr_shrink)
+{
+ struct erofs_workgroup *grp;
+ unsigned int freed = 0;
+ unsigned long index;
+
+ xa_lock(&sbi->managed_pslots);
+ xa_for_each(&sbi->managed_pslots, index, grp) {
+ /* try to shrink each valid pcluster */
+ if (!erofs_try_to_release_pcluster(sbi, grp))
+ continue;
+ xa_unlock(&sbi->managed_pslots);
+
+ ++freed;
+ if (!--nr_shrink)
+ return freed;
+ xa_lock(&sbi->managed_pslots);
+ }
+ xa_unlock(&sbi->managed_pslots);
+ return freed;
+}
+
+static void z_erofs_put_pcluster(struct z_erofs_pcluster *pcl)
+{
+ struct erofs_workgroup *grp = &pcl->obj;
+
+ if (lockref_put_or_lock(&grp->lockref))
+ return;
+
+ DBG_BUGON(__lockref_is_dead(&grp->lockref));
+ if (grp->lockref.count == 1)
+ atomic_long_inc(&erofs_global_shrink_cnt);
+ --grp->lockref.count;
+ spin_unlock(&grp->lockref.lock);
+}
+
static void z_erofs_pcluster_end(struct z_erofs_decompress_frontend *fe)
{
struct z_erofs_pcluster *pcl = fe->pcl;
@@ -895,7 +983,7 @@ static void z_erofs_pcluster_end(struct z_erofs_decompress_frontend *fe)
* any longer if the pcluster isn't hosted by ourselves.
*/
if (fe->mode < Z_EROFS_PCLUSTER_FOLLOWED_NOINPLACE)
- erofs_workgroup_put(&pcl->obj);
+ z_erofs_put_pcluster(pcl);
fe->pcl = NULL;
}
@@ -1327,7 +1415,7 @@ static int z_erofs_decompress_queue(const struct z_erofs_decompressqueue *io,
if (z_erofs_is_inline_pcluster(be.pcl))
z_erofs_free_pcluster(be.pcl);
else
- erofs_workgroup_put(&be.pcl->obj);
+ z_erofs_put_pcluster(be.pcl);
}
return err;
}
diff --git a/fs/erofs/zutil.c b/fs/erofs/zutil.c
index 218b0249a4822..75704f58ecfa9 100644
--- a/fs/erofs/zutil.c
+++ b/fs/erofs/zutil.c
@@ -2,6 +2,7 @@
/*
* Copyright (C) 2018 HUAWEI, Inc.
* https://www.huawei.com/
+ * Copyright (C) 2024 Alibaba Cloud
*/
#include "internal.h"
@@ -19,13 +20,12 @@ static unsigned int z_erofs_gbuf_count, z_erofs_gbuf_nrpages,
module_param_named(global_buffers, z_erofs_gbuf_count, uint, 0444);
module_param_named(reserved_pages, z_erofs_rsv_nrpages, uint, 0444);
-static atomic_long_t erofs_global_shrink_cnt; /* for all mounted instances */
-/* protected by 'erofs_sb_list_lock' */
-static unsigned int shrinker_run_no;
+atomic_long_t erofs_global_shrink_cnt; /* for all mounted instances */
-/* protects the mounted 'erofs_sb_list' */
+/* protects `erofs_sb_list_lock` and the mounted `erofs_sb_list` */
static DEFINE_SPINLOCK(erofs_sb_list_lock);
static LIST_HEAD(erofs_sb_list);
+static unsigned int shrinker_run_no;
static struct shrinker *erofs_shrinker_info;
static unsigned int z_erofs_gbuf_id(void)
@@ -214,97 +214,6 @@ void erofs_release_pages(struct page **pagepool)
}
}
-bool erofs_workgroup_get(struct erofs_workgroup *grp)
-{
- if (lockref_get_not_zero(&grp->lockref))
- return true;
-
- spin_lock(&grp->lockref.lock);
- if (__lockref_is_dead(&grp->lockref)) {
- spin_unlock(&grp->lockref.lock);
- return false;
- }
-
- if (!grp->lockref.count++)
- atomic_long_dec(&erofs_global_shrink_cnt);
- spin_unlock(&grp->lockref.lock);
- return true;
-}
-
-static void __erofs_workgroup_free(struct erofs_workgroup *grp)
-{
- atomic_long_dec(&erofs_global_shrink_cnt);
- erofs_workgroup_free_rcu(grp);
-}
-
-void erofs_workgroup_put(struct erofs_workgroup *grp)
-{
- if (lockref_put_or_lock(&grp->lockref))
- return;
-
- DBG_BUGON(__lockref_is_dead(&grp->lockref));
- if (grp->lockref.count == 1)
- atomic_long_inc(&erofs_global_shrink_cnt);
- --grp->lockref.count;
- spin_unlock(&grp->lockref.lock);
-}
-
-static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi,
- struct erofs_workgroup *grp)
-{
- int free = false;
-
- spin_lock(&grp->lockref.lock);
- if (grp->lockref.count)
- goto out;
-
- /*
- * Note that all cached pages should be detached before deleted from
- * the XArray. Otherwise some cached pages could be still attached to
- * the orphan old workgroup when the new one is available in the tree.
- */
- if (erofs_try_to_free_all_cached_folios(sbi, grp))
- goto out;
-
- /*
- * It's impossible to fail after the workgroup is freezed,
- * however in order to avoid some race conditions, add a
- * DBG_BUGON to observe this in advance.
- */
- DBG_BUGON(__xa_erase(&sbi->managed_pslots, grp->index) != grp);
-
- lockref_mark_dead(&grp->lockref);
- free = true;
-out:
- spin_unlock(&grp->lockref.lock);
- if (free)
- __erofs_workgroup_free(grp);
- return free;
-}
-
-static unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
- unsigned long nr_shrink)
-{
- struct erofs_workgroup *grp;
- unsigned int freed = 0;
- unsigned long index;
-
- xa_lock(&sbi->managed_pslots);
- xa_for_each(&sbi->managed_pslots, index, grp) {
- /* try to shrink each valid workgroup */
- if (!erofs_try_to_release_workgroup(sbi, grp))
- continue;
- xa_unlock(&sbi->managed_pslots);
-
- ++freed;
- if (!--nr_shrink)
- return freed;
- xa_lock(&sbi->managed_pslots);
- }
- xa_unlock(&sbi->managed_pslots);
- return freed;
-}
-
void erofs_shrinker_register(struct super_block *sb)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);
@@ -321,8 +230,8 @@ void erofs_shrinker_unregister(struct super_block *sb)
struct erofs_sb_info *const sbi = EROFS_SB(sb);
mutex_lock(&sbi->umount_mutex);
- /* clean up all remaining workgroups in memory */
- erofs_shrink_workstation(sbi, ~0UL);
+ /* clean up all remaining pclusters in memory */
+ z_erofs_shrink_scan(sbi, ~0UL);
spin_lock(&erofs_sb_list_lock);
list_del(&sbi->list);
@@ -370,9 +279,7 @@ static unsigned long erofs_shrink_scan(struct shrinker *shrink,
spin_unlock(&erofs_sb_list_lock);
sbi->shrinker_run_no = run_no;
-
- freed += erofs_shrink_workstation(sbi, nr - freed);
-
+ freed += z_erofs_shrink_scan(sbi, nr - freed);
spin_lock(&erofs_sb_list_lock);
/* Get the next list element before we move this one */
p = p->next;
