This is a note to let you know that I've just added the patch titled
erofs: get rid of erofs_{find,insert}_workgroup
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-get-rid-of-erofs_-find-insert-_workgroup.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 df31b3fb4d84962bc7f0268bd82cec1b16996feb
Author: Gao Xiang <xiang@xxxxxxxxxx>
Date: Mon Oct 21 11:53:21 2024 +0800
erofs: get rid of erofs_{find,insert}_workgroup
[ Upstream commit b091e8ed24b7965953147a389bac1dc7c3e8a11c ]
Just fold them into the only two callers since
they are simple enough.
Reviewed-by: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20241021035323.3280682-1-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 77e785a6dfa7f..b9649e3b2dd56 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -453,10 +453,7 @@ void erofs_release_pages(struct page **pagepool);
#ifdef CONFIG_EROFS_FS_ZIP
void erofs_workgroup_put(struct erofs_workgroup *grp);
-struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
- pgoff_t index);
-struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
- struct erofs_workgroup *grp);
+bool erofs_workgroup_get(struct erofs_workgroup *grp);
void erofs_workgroup_free_rcu(struct erofs_workgroup *grp);
void erofs_shrinker_register(struct super_block *sb);
void erofs_shrinker_unregister(struct super_block *sb);
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 1a00f061798a3..8c6082fc86b29 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -714,9 +714,10 @@ static int z_erofs_register_pcluster(struct z_erofs_decompress_frontend *fe)
{
struct erofs_map_blocks *map = &fe->map;
struct super_block *sb = fe->inode->i_sb;
+ struct erofs_sb_info *sbi = EROFS_SB(sb);
bool ztailpacking = map->m_flags & EROFS_MAP_META;
struct z_erofs_pcluster *pcl;
- struct erofs_workgroup *grp;
+ struct erofs_workgroup *grp, *pre;
int err;
if (!(map->m_flags & EROFS_MAP_ENCODED) ||
@@ -752,15 +753,23 @@ static int z_erofs_register_pcluster(struct z_erofs_decompress_frontend *fe)
pcl->obj.index = 0; /* which indicates ztailpacking */
} else {
pcl->obj.index = erofs_blknr(sb, map->m_pa);
-
- grp = erofs_insert_workgroup(fe->inode->i_sb, &pcl->obj);
- if (IS_ERR(grp)) {
- err = PTR_ERR(grp);
- goto err_out;
+ while (1) {
+ 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)) {
+ xa_unlock(&sbi->managed_pslots);
+ break;
+ }
+ /* try to legitimize the current in-tree one */
+ xa_unlock(&sbi->managed_pslots);
+ cond_resched();
}
-
- if (grp != &pcl->obj) {
- fe->pcl = container_of(grp,
+ if (xa_is_err(pre)) {
+ err = xa_err(pre);
+ goto err_out;
+ } else if (pre) {
+ fe->pcl = container_of(pre,
struct z_erofs_pcluster, obj);
err = -EEXIST;
goto err_out;
@@ -789,7 +798,16 @@ static int z_erofs_pcluster_begin(struct z_erofs_decompress_frontend *fe)
DBG_BUGON(fe->owned_head == Z_EROFS_PCLUSTER_NIL);
if (!(map->m_flags & EROFS_MAP_META)) {
- grp = erofs_find_workgroup(sb, blknr);
+ while (1) {
+ rcu_read_lock();
+ grp = xa_load(&EROFS_SB(sb)->managed_pslots, blknr);
+ if (!grp || erofs_workgroup_get(grp)) {
+ DBG_BUGON(grp && blknr != grp->index);
+ rcu_read_unlock();
+ break;
+ }
+ rcu_read_unlock();
+ }
} else if ((map->m_pa & ~PAGE_MASK) + map->m_plen > PAGE_SIZE) {
DBG_BUGON(1);
return -EFSCORRUPTED;
diff --git a/fs/erofs/zutil.c b/fs/erofs/zutil.c
index 37afe20248409..218b0249a4822 100644
--- a/fs/erofs/zutil.c
+++ b/fs/erofs/zutil.c
@@ -214,7 +214,7 @@ void erofs_release_pages(struct page **pagepool)
}
}
-static bool erofs_workgroup_get(struct erofs_workgroup *grp)
+bool erofs_workgroup_get(struct erofs_workgroup *grp)
{
if (lockref_get_not_zero(&grp->lockref))
return true;
@@ -231,54 +231,6 @@ static bool erofs_workgroup_get(struct erofs_workgroup *grp)
return true;
}
-struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
- pgoff_t index)
-{
- struct erofs_sb_info *sbi = EROFS_SB(sb);
- struct erofs_workgroup *grp;
-
-repeat:
- rcu_read_lock();
- grp = xa_load(&sbi->managed_pslots, index);
- if (grp) {
- if (!erofs_workgroup_get(grp)) {
- /* prefer to relax rcu read side */
- rcu_read_unlock();
- goto repeat;
- }
-
- DBG_BUGON(index != grp->index);
- }
- rcu_read_unlock();
- return grp;
-}
-
-struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
- struct erofs_workgroup *grp)
-{
- struct erofs_sb_info *const sbi = EROFS_SB(sb);
- struct erofs_workgroup *pre;
-
- DBG_BUGON(grp->lockref.count < 1);
-repeat:
- xa_lock(&sbi->managed_pslots);
- pre = __xa_cmpxchg(&sbi->managed_pslots, grp->index,
- NULL, grp, GFP_KERNEL);
- if (pre) {
- if (xa_is_err(pre)) {
- pre = ERR_PTR(xa_err(pre));
- } else if (!erofs_workgroup_get(pre)) {
- /* try to legitimize the current in-tree one */
- xa_unlock(&sbi->managed_pslots);
- cond_resched();
- goto repeat;
- }
- grp = pre;
- }
- xa_unlock(&sbi->managed_pslots);
- return grp;
-}
-
static void __erofs_workgroup_free(struct erofs_workgroup *grp)
{
atomic_long_dec(&erofs_global_shrink_cnt);
