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-rw-r--r--fs/super.c201
1 files changed, 78 insertions, 123 deletions
diff --git a/fs/super.c b/fs/super.c
index 0225c20f877..e5f6c2cfac3 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -129,33 +129,24 @@ static unsigned long super_cache_count(struct shrinker *shrink,
return total_objects;
}
-static int init_sb_writers(struct super_block *s, struct file_system_type *type)
-{
- int err;
- int i;
-
- for (i = 0; i < SB_FREEZE_LEVELS; i++) {
- err = percpu_counter_init(&s->s_writers.counter[i], 0);
- if (err < 0)
- goto err_out;
- lockdep_init_map(&s->s_writers.lock_map[i], sb_writers_name[i],
- &type->s_writers_key[i], 0);
- }
- init_waitqueue_head(&s->s_writers.wait);
- init_waitqueue_head(&s->s_writers.wait_unfrozen);
- return 0;
-err_out:
- while (--i >= 0)
- percpu_counter_destroy(&s->s_writers.counter[i]);
- return err;
-}
-
-static void destroy_sb_writers(struct super_block *s)
+/**
+ * destroy_super - frees a superblock
+ * @s: superblock to free
+ *
+ * Frees a superblock.
+ */
+static void destroy_super(struct super_block *s)
{
int i;
-
+ list_lru_destroy(&s->s_dentry_lru);
+ list_lru_destroy(&s->s_inode_lru);
for (i = 0; i < SB_FREEZE_LEVELS; i++)
percpu_counter_destroy(&s->s_writers.counter[i]);
+ security_sb_free(s);
+ WARN_ON(!list_empty(&s->s_mounts));
+ kfree(s->s_subtype);
+ kfree(s->s_options);
+ kfree_rcu(s, rcu);
}
/**
@@ -170,111 +161,74 @@ static struct super_block *alloc_super(struct file_system_type *type, int flags)
{
struct super_block *s = kzalloc(sizeof(struct super_block), GFP_USER);
static const struct super_operations default_op;
+ int i;
- if (s) {
- if (security_sb_alloc(s))
- goto out_free_sb;
+ if (!s)
+ return NULL;
-#ifdef CONFIG_SMP
- s->s_files = alloc_percpu(struct list_head);
- if (!s->s_files)
- goto err_out;
- else {
- int i;
+ if (security_sb_alloc(s))
+ goto fail;
- for_each_possible_cpu(i)
- INIT_LIST_HEAD(per_cpu_ptr(s->s_files, i));
- }
-#else
- INIT_LIST_HEAD(&s->s_files);
-#endif
- if (init_sb_writers(s, type))
- goto err_out;
- s->s_flags = flags;
- s->s_bdi = &default_backing_dev_info;
- INIT_HLIST_NODE(&s->s_instances);
- INIT_HLIST_BL_HEAD(&s->s_anon);
- INIT_LIST_HEAD(&s->s_inodes);
-
- if (list_lru_init(&s->s_dentry_lru))
- goto err_out;
- if (list_lru_init(&s->s_inode_lru))
- goto err_out_dentry_lru;
-
- INIT_LIST_HEAD(&s->s_mounts);
- init_rwsem(&s->s_umount);
- lockdep_set_class(&s->s_umount, &type->s_umount_key);
- /*
- * sget() can have s_umount recursion.
- *
- * When it cannot find a suitable sb, it allocates a new
- * one (this one), and tries again to find a suitable old
- * one.
- *
- * In case that succeeds, it will acquire the s_umount
- * lock of the old one. Since these are clearly distrinct
- * locks, and this object isn't exposed yet, there's no
- * risk of deadlocks.
- *
- * Annotate this by putting this lock in a different
- * subclass.
- */
- down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING);
- s->s_count = 1;
- atomic_set(&s->s_active, 1);
- mutex_init(&s->s_vfs_rename_mutex);
- lockdep_set_class(&s->s_vfs_rename_mutex, &type->s_vfs_rename_key);
- mutex_init(&s->s_dquot.dqio_mutex);
- mutex_init(&s->s_dquot.dqonoff_mutex);
- init_rwsem(&s->s_dquot.dqptr_sem);
- s->s_maxbytes = MAX_NON_LFS;
- s->s_op = &default_op;
- s->s_time_gran = 1000000000;
- s->cleancache_poolid = -1;
-
- s->s_shrink.seeks = DEFAULT_SEEKS;
- s->s_shrink.scan_objects = super_cache_scan;
- s->s_shrink.count_objects = super_cache_count;
- s->s_shrink.batch = 1024;
- s->s_shrink.flags = SHRINKER_NUMA_AWARE;
+ for (i = 0; i < SB_FREEZE_LEVELS; i++) {
+ if (percpu_counter_init(&s->s_writers.counter[i], 0) < 0)
+ goto fail;
+ lockdep_init_map(&s->s_writers.lock_map[i], sb_writers_name[i],
+ &type->s_writers_key[i], 0);
}
-out:
+ init_waitqueue_head(&s->s_writers.wait);
+ init_waitqueue_head(&s->s_writers.wait_unfrozen);
+ s->s_flags = flags;
+ s->s_bdi = &default_backing_dev_info;
+ INIT_HLIST_NODE(&s->s_instances);
+ INIT_HLIST_BL_HEAD(&s->s_anon);
+ INIT_LIST_HEAD(&s->s_inodes);
+
+ if (list_lru_init(&s->s_dentry_lru))
+ goto fail;
+ if (list_lru_init(&s->s_inode_lru))
+ goto fail;
+
+ INIT_LIST_HEAD(&s->s_mounts);
+ init_rwsem(&s->s_umount);
+ lockdep_set_class(&s->s_umount, &type->s_umount_key);
+ /*
+ * sget() can have s_umount recursion.
+ *
+ * When it cannot find a suitable sb, it allocates a new
+ * one (this one), and tries again to find a suitable old
+ * one.
+ *
+ * In case that succeeds, it will acquire the s_umount
+ * lock of the old one. Since these are clearly distrinct
+ * locks, and this object isn't exposed yet, there's no
+ * risk of deadlocks.
+ *
+ * Annotate this by putting this lock in a different
+ * subclass.
+ */
+ down_write_nested(&s->s_umount, SINGLE_DEPTH_NESTING);
+ s->s_count = 1;
+ atomic_set(&s->s_active, 1);
+ mutex_init(&s->s_vfs_rename_mutex);
+ lockdep_set_class(&s->s_vfs_rename_mutex, &type->s_vfs_rename_key);
+ mutex_init(&s->s_dquot.dqio_mutex);
+ mutex_init(&s->s_dquot.dqonoff_mutex);
+ init_rwsem(&s->s_dquot.dqptr_sem);
+ s->s_maxbytes = MAX_NON_LFS;
+ s->s_op = &default_op;
+ s->s_time_gran = 1000000000;
+ s->cleancache_poolid = -1;
+
+ s->s_shrink.seeks = DEFAULT_SEEKS;
+ s->s_shrink.scan_objects = super_cache_scan;
+ s->s_shrink.count_objects = super_cache_count;
+ s->s_shrink.batch = 1024;
+ s->s_shrink.flags = SHRINKER_NUMA_AWARE;
return s;
-err_out_dentry_lru:
- list_lru_destroy(&s->s_dentry_lru);
-err_out:
- security_sb_free(s);
-#ifdef CONFIG_SMP
- if (s->s_files)
- free_percpu(s->s_files);
-#endif
- destroy_sb_writers(s);
-out_free_sb:
- kfree(s);
- s = NULL;
- goto out;
-}
-
-/**
- * destroy_super - frees a superblock
- * @s: superblock to free
- *
- * Frees a superblock.
- */
-static inline void destroy_super(struct super_block *s)
-{
- list_lru_destroy(&s->s_dentry_lru);
- list_lru_destroy(&s->s_inode_lru);
-#ifdef CONFIG_SMP
- free_percpu(s->s_files);
-#endif
- destroy_sb_writers(s);
- security_sb_free(s);
- WARN_ON(!list_empty(&s->s_mounts));
- kfree(s->s_subtype);
- kfree(s->s_options);
- kfree(s);
+fail:
+ destroy_super(s);
+ return NULL;
}
/* Superblock refcounting */
@@ -756,7 +710,8 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force)
make sure there are no rw files opened */
if (remount_ro) {
if (force) {
- mark_files_ro(sb);
+ sb->s_readonly_remount = 1;
+ smp_wmb();
} else {
retval = sb_prepare_remount_readonly(sb);
if (retval)
generated by cgit v1.2.3-18-g5258 (git 2.32.0) at 2024-12-24 11:33:44 +0000