It shall be [PATCH vz8] - sorry for missing that.
vz7/vz8/vz9?
--
Best regards,
Konstantin Khorenko,
Virtuozzo Linux Kernel Team
On 18.10.2021 19:51, Nikita Yushchenko wrote:
The assumption that bm_fill_super() is not called for the second time
for CT is wrong: umount operation clears sb->s_root, which causes
vfs_get_super() to call fill_super again on the next mount.
Make bm_fill_super() handle multiple-calls corrently:
- initialize bm_data and set ve->binfmt_misc only if it is not done
before,
- delay desctruction of it up to CT destruction.
https://jira.sw.ru/browse/PSBM-133968
Fixes: 8250ff41d190 ("ve/fs/binfmt: clean bm_data reference from ve on err
path")
Signed-off-by: Nikita Yushchenko <nikita.yushche...@virtuozzo.com>
---
fs/binfmt_misc.c | 37 +++++++++++++------------------------
1 file changed, 13 insertions(+), 24 deletions(-)
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index 0946e7e6caa5..5f4e90c1ade2 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -853,38 +853,25 @@ static int bm_fill_super(struct super_block *sb, struct
fs_context *fc)
};
struct ve_struct *ve = get_exec_env();
- struct binfmt_misc *bm_data;
+ struct binfmt_misc *bm_data = ve->binfmt_misc;
- /*
- * bm_get_tree()
- * get_tree_keyed(fc, bm_fill_super, get_ve(ve))
- * fc->s_fs_info = current VE
- * vfs_get_super(fc, vfs_get_keyed_super, bm_fill_super)
- * sb = sget_fc(fc, test, set_anon_super_fc)
- * if (!sb->s_root) {
- * err = bm_fill_super(sb, fc);
- *
- * => we should never get here with initialized ve->binfmt_misc.
- */
- if (WARN_ON_ONCE(ve->binfmt_misc))
- return -EEXIST;
+ if (!bm_data) {
+ bm_data = kzalloc(sizeof(struct binfmt_misc), GFP_KERNEL);
+ if (!bm_data)
+ return -ENOMEM;
- bm_data = kzalloc(sizeof(struct binfmt_misc), GFP_KERNEL);
- if (!bm_data)
- return -ENOMEM;
+ INIT_LIST_HEAD(&bm_data->entries);
+ rwlock_init(&bm_data->entries_lock);
- INIT_LIST_HEAD(&bm_data->entries);
- rwlock_init(&bm_data->entries_lock);
+ ve->binfmt_misc = bm_data;
+ /* this will be cleared by ve_binfmt_fini() */
+ }
err = simple_fill_super(sb, BINFMTFS_MAGIC, bm_files);
- if (err) {
- kfree(bm_data);
+ if (err)
return err;
- }
sb->s_op = &s_ops;
-
- ve->binfmt_misc = bm_data;
bm_data->enabled = 1;
return 0;
@@ -971,6 +958,8 @@ static void ve_binfmt_fini(void *data)
while (!list_empty(&bm_data->entries))
kill_node(bm_data, list_first_entry(
&bm_data->entries, Node, list));
+
+ kfree(bm_data);
}
static struct ve_hook ve_binfmt_hook = {
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