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-rw-r--r--fs/erofs/internal.h8
-rw-r--r--fs/erofs/super.c2
-rw-r--r--fs/erofs/utils.c88
-rw-r--r--fs/erofs/zdata.c76
4 files changed, 76 insertions, 98 deletions
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index c4c6dcdc89ad..5eead7fdc7a6 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -52,8 +52,8 @@ struct erofs_sb_info {
struct list_head list;
struct mutex umount_mutex;
- /* the dedicated workstation for compression */
- struct radix_tree_root workstn_tree;
+ /* managed XArray arranged in physical block number */
+ struct xarray managed_pslots;
/* threshold for decompression synchronously */
unsigned int max_sync_decompress_pages;
@@ -402,8 +402,8 @@ static inline void *erofs_get_pcpubuf(unsigned int pagenr)
int erofs_workgroup_put(struct erofs_workgroup *grp);
struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
pgoff_t index);
-int erofs_register_workgroup(struct super_block *sb,
- struct erofs_workgroup *grp);
+struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
+ 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/super.c b/fs/erofs/super.c
index 057e6d7b5b7f..b514c67e5fc2 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -425,7 +425,7 @@ static int erofs_fill_super(struct super_block *sb, void *data, int silent)
sb->s_flags &= ~SB_POSIXACL;
#ifdef CONFIG_EROFS_FS_ZIP
- INIT_RADIX_TREE(&sbi->workstn_tree, GFP_ATOMIC);
+ xa_init(&sbi->managed_pslots);
#endif
/* get the root inode */
diff --git a/fs/erofs/utils.c b/fs/erofs/utils.c
index fddc5059c930..4396b424373f 100644
--- a/fs/erofs/utils.c
+++ b/fs/erofs/utils.c
@@ -37,9 +37,6 @@ void *erofs_get_pcpubuf(unsigned int pagenr)
/* global shrink count (for all mounted EROFS instances) */
static atomic_long_t erofs_global_shrink_cnt;
-#define __erofs_workgroup_get(grp) atomic_inc(&(grp)->refcount)
-#define __erofs_workgroup_put(grp) atomic_dec(&(grp)->refcount)
-
static int erofs_workgroup_get(struct erofs_workgroup *grp)
{
int o;
@@ -66,7 +63,7 @@ struct erofs_workgroup *erofs_find_workgroup(struct super_block *sb,
repeat:
rcu_read_lock();
- grp = radix_tree_lookup(&sbi->workstn_tree, index);
+ grp = xa_load(&sbi->managed_pslots, index);
if (grp) {
if (erofs_workgroup_get(grp)) {
/* prefer to relax rcu read side */
@@ -80,43 +77,37 @@ repeat:
return grp;
}
-int erofs_register_workgroup(struct super_block *sb,
- struct erofs_workgroup *grp)
+struct erofs_workgroup *erofs_insert_workgroup(struct super_block *sb,
+ struct erofs_workgroup *grp)
{
- struct erofs_sb_info *sbi;
- int err;
-
- /* grp shouldn't be broken or used before */
- if (atomic_read(&grp->refcount) != 1) {
- DBG_BUGON(1);
- return -EINVAL;
- }
-
- err = radix_tree_preload(GFP_NOFS);
- if (err)
- return err;
-
- sbi = EROFS_SB(sb);
- xa_lock(&sbi->workstn_tree);
+ struct erofs_sb_info *const sbi = EROFS_SB(sb);
+ struct erofs_workgroup *pre;
/*
- * Bump up reference count before making this workgroup
- * visible to other users in order to avoid potential UAF
- * without serialized by workstn_lock.
+ * Bump up a reference count before making this visible
+ * to others for the XArray in order to avoid potential
+ * UAF without serialized by xa_lock.
*/
- __erofs_workgroup_get(grp);
-
- err = radix_tree_insert(&sbi->workstn_tree, grp->index, grp);
- if (err)
- /*
- * it's safe to decrease since the workgroup isn't visible
- * and refcount >= 2 (cannot be freezed).
- */
- __erofs_workgroup_put(grp);
+ atomic_inc(&grp->refcount);
- xa_unlock(&sbi->workstn_tree);
- radix_tree_preload_end();
- return err;
+repeat:
+ xa_lock(&sbi->managed_pslots);
+ pre = __xa_cmpxchg(&sbi->managed_pslots, grp->index,
+ NULL, grp, GFP_NOFS);
+ 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;
+ }
+ atomic_dec(&grp->refcount);
+ grp = pre;
+ }
+ xa_unlock(&sbi->managed_pslots);
+ return grp;
}
static void __erofs_workgroup_free(struct erofs_workgroup *grp)
@@ -155,7 +146,7 @@ static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi,
/*
* Note that all cached pages should be unattached
- * before deleted from the radix tree. Otherwise some
+ * 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.
*/
@@ -169,7 +160,7 @@ static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi,
* however in order to avoid some race conditions, add a
* DBG_BUGON to observe this in advance.
*/
- DBG_BUGON(radix_tree_delete(&sbi->workstn_tree, grp->index) != grp);
+ DBG_BUGON(xa_erase(&sbi->managed_pslots, grp->index) != grp);
/*
* If managed cache is on, last refcount should indicate
@@ -182,22 +173,11 @@ static bool erofs_try_to_release_workgroup(struct erofs_sb_info *sbi,
static unsigned long erofs_shrink_workstation(struct erofs_sb_info *sbi,
unsigned long nr_shrink)
{
- pgoff_t first_index = 0;
- void *batch[PAGEVEC_SIZE];
+ struct erofs_workgroup *grp;
unsigned int freed = 0;
+ unsigned long index;
- int i, found;
-repeat:
- xa_lock(&sbi->workstn_tree);
-
- found = radix_tree_gang_lookup(&sbi->workstn_tree,
- batch, first_index, PAGEVEC_SIZE);
-
- for (i = 0; i < found; ++i) {
- struct erofs_workgroup *grp = batch[i];
-
- first_index = grp->index + 1;
-
+ xa_for_each(&sbi->managed_pslots, index, grp) {
/* try to shrink each valid workgroup */
if (!erofs_try_to_release_workgroup(sbi, grp))
continue;
@@ -206,10 +186,6 @@ repeat:
if (!--nr_shrink)
break;
}
- xa_unlock(&sbi->workstn_tree);
-
- if (i && nr_shrink)
- goto repeat;
return freed;
}
diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 80e47f07d946..c4b6c9aa87ec 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -67,16 +67,6 @@ static void z_erofs_pcluster_init_once(void *ptr)
pcl->compressed_pages[i] = NULL;
}
-static void z_erofs_pcluster_init_always(struct z_erofs_pcluster *pcl)
-{
- struct z_erofs_collection *cl = z_erofs_primarycollection(pcl);
-
- atomic_set(&pcl->obj.refcount, 1);
-
- DBG_BUGON(cl->nr_pages);
- DBG_BUGON(cl->vcnt);
-}
-
int __init z_erofs_init_zip_subsystem(void)
{
pcluster_cachep = kmem_cache_create("erofs_compress",
@@ -341,26 +331,19 @@ static int z_erofs_lookup_collection(struct z_erofs_collector *clt,
struct inode *inode,
struct erofs_map_blocks *map)
{
- struct erofs_workgroup *grp;
- struct z_erofs_pcluster *pcl;
+ struct z_erofs_pcluster *pcl = clt->pcl;
struct z_erofs_collection *cl;
unsigned int length;
- grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT);
- if (!grp)
- return -ENOENT;
-
- pcl = container_of(grp, struct z_erofs_pcluster, obj);
+ /* to avoid unexpected loop formed by corrupted images */
if (clt->owned_head == &pcl->next || pcl == clt->tailpcl) {
DBG_BUGON(1);
- erofs_workgroup_put(grp);
return -EFSCORRUPTED;
}
cl = z_erofs_primarycollection(pcl);
if (cl->pageofs != (map->m_la & ~PAGE_MASK)) {
DBG_BUGON(1);
- erofs_workgroup_put(grp);
return -EFSCORRUPTED;
}
@@ -368,7 +351,6 @@ static int z_erofs_lookup_collection(struct z_erofs_collector *clt,
if (length & Z_EROFS_PCLUSTER_FULL_LENGTH) {
if ((map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) > length) {
DBG_BUGON(1);
- erofs_workgroup_put(grp);
return -EFSCORRUPTED;
}
} else {
@@ -391,7 +373,6 @@ static int z_erofs_lookup_collection(struct z_erofs_collector *clt,
/* clean tailpcl if the current owned_head is Z_EROFS_PCLUSTER_TAIL */
if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
clt->tailpcl = NULL;
- clt->pcl = pcl;
clt->cl = cl;
return 0;
}
@@ -402,6 +383,7 @@ static int z_erofs_register_collection(struct z_erofs_collector *clt,
{
struct z_erofs_pcluster *pcl;
struct z_erofs_collection *cl;
+ struct erofs_workgroup *grp;
int err;
/* no available workgroup, let's allocate one */
@@ -409,7 +391,7 @@ static int z_erofs_register_collection(struct z_erofs_collector *clt,
if (!pcl)
return -ENOMEM;
- z_erofs_pcluster_init_always(pcl);
+ atomic_set(&pcl->obj.refcount, 1);
pcl->obj.index = map->m_pa >> PAGE_SHIFT;
pcl->length = (map->m_llen << Z_EROFS_PCLUSTER_LENGTH_BIT) |
@@ -429,19 +411,29 @@ static int z_erofs_register_collection(struct z_erofs_collector *clt,
clt->mode = COLLECT_PRIMARY_FOLLOWED;
cl = z_erofs_primarycollection(pcl);
+
+ /* must be cleaned before freeing to slab */
+ DBG_BUGON(cl->nr_pages);
+ DBG_BUGON(cl->vcnt);
+
cl->pageofs = map->m_la & ~PAGE_MASK;
/*
* lock all primary followed works before visible to others
* and mutex_trylock *never* fails for a new pcluster.
*/
- mutex_trylock(&cl->lock);
+ DBG_BUGON(!mutex_trylock(&cl->lock));
- err = erofs_register_workgroup(inode->i_sb, &pcl->obj);
- if (err) {
- mutex_unlock(&cl->lock);
- kmem_cache_free(pcluster_cachep, pcl);
- return -EAGAIN;
+ grp = erofs_insert_workgroup(inode->i_sb, &pcl->obj);
+ if (IS_ERR(grp)) {
+ err = PTR_ERR(grp);
+ goto err_out;
+ }
+
+ if (grp != &pcl->obj) {
+ clt->pcl = container_of(grp, struct z_erofs_pcluster, obj);
+ err = -EEXIST;
+ goto err_out;
}
/* used to check tail merging loop due to corrupted images */
if (clt->owned_head == Z_EROFS_PCLUSTER_TAIL)
@@ -450,12 +442,18 @@ static int z_erofs_register_collection(struct z_erofs_collector *clt,
clt->pcl = pcl;
clt->cl = cl;
return 0;
+
+err_out:
+ mutex_unlock(&cl->lock);
+ kmem_cache_free(pcluster_cachep, pcl);
+ return err;
}
static int z_erofs_collector_begin(struct z_erofs_collector *clt,
struct inode *inode,
struct erofs_map_blocks *map)
{
+ struct erofs_workgroup *grp;
int ret;
DBG_BUGON(clt->cl);
@@ -469,21 +467,25 @@ static int z_erofs_collector_begin(struct z_erofs_collector *clt,
return -EINVAL;
}
-repeat:
- ret = z_erofs_lookup_collection(clt, inode, map);
- if (ret == -ENOENT) {
+ grp = erofs_find_workgroup(inode->i_sb, map->m_pa >> PAGE_SHIFT);
+ if (grp) {
+ clt->pcl = container_of(grp, struct z_erofs_pcluster, obj);
+ } else {
ret = z_erofs_register_collection(clt, inode, map);
- /* someone registered at the same time, give another try */
- if (ret == -EAGAIN) {
- cond_resched();
- goto repeat;
- }
+ if (!ret)
+ goto out;
+ if (ret != -EEXIST)
+ return ret;
}
- if (ret)
+ ret = z_erofs_lookup_collection(clt, inode, map);
+ if (ret) {
+ erofs_workgroup_put(&clt->pcl->obj);
return ret;
+ }
+out:
z_erofs_pagevec_ctor_init(&clt->vector, Z_EROFS_NR_INLINE_PAGEVECS,
clt->cl->pagevec, clt->cl->vcnt);
generated by cgit (git 2.34.1) at 2024-06-03 16:52:36 +0000