This relieves us of the requirement to have a struct path and use file
operations, which greatly simplifies the code. The superblock is now
pinned by the blocking notifier (which is why deregistration moves
above kill_litter_super).
Signed-off-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx>
---
fs/efivarfs/super.c | 103 +++-----------------------------------------
1 file changed, 7 insertions(+), 96 deletions(-)
diff --git a/fs/efivarfs/super.c b/fs/efivarfs/super.c
index 81b3c6b7e100..135b0bb9b4b5 100644
--- a/fs/efivarfs/super.c
+++ b/fs/efivarfs/super.c
@@ -393,29 +393,13 @@ static const struct fs_context_operations efivarfs_context_ops = {
.reconfigure = efivarfs_reconfigure,
};
-struct efivarfs_ctx {
- struct dir_context ctx;
- struct super_block *sb;
- struct dentry *dentry;
-};
-
-static bool efivarfs_actor(struct dir_context *ctx, const char *name, int len,
- loff_t offset, u64 ino, unsigned mode)
+static bool efivarfs_iterate_callback(void *data, struct dentry *dentry)
{
unsigned long size;
- struct efivarfs_ctx *ectx = container_of(ctx, struct efivarfs_ctx, ctx);
- struct qstr qstr = { .name = name, .len = len };
- struct dentry *dentry = d_hash_and_lookup(ectx->sb->s_root, &qstr);
- struct inode *inode;
- struct efivar_entry *entry;
+ struct inode *inode = d_inode(dentry);
+ struct efivar_entry *entry = efivar_entry(inode);
int err;
- if (IS_ERR_OR_NULL(dentry))
- return true;
-
- inode = d_inode(dentry);
- entry = efivar_entry(inode);
-
err = efivar_entry_size(entry, &size);
size += sizeof(__u32); /* attributes */
if (err)
@@ -426,12 +410,10 @@ static bool efivarfs_actor(struct dir_context *ctx, const char *name, int len,
inode_unlock(inode);
if (!size) {
- ectx->dentry = dentry;
- return false;
+ pr_info("efivarfs: removing variable %pd\n", dentry);
+ simple_recursive_removal(dentry, NULL);
}
- dput(dentry);
-
return true;
}
@@ -474,33 +456,11 @@ static int efivarfs_check_missing(efi_char16_t *name16, efi_guid_t vendor,
return err;
}
-static void efivarfs_deactivate_super_work(struct work_struct *work)
-{
- struct super_block *s = container_of(work, struct super_block,
- destroy_work);
- /*
- * note: here s->destroy_work is free for reuse (which
- * will happen in deactivate_super)
- */
- deactivate_super(s);
-}
-
-static struct file_system_type efivarfs_type;
-
static int efivarfs_pm_notify(struct notifier_block *nb, unsigned long action,
void *ptr)
{
struct efivarfs_fs_info *sfi = container_of(nb, struct efivarfs_fs_info,
pm_nb);
- struct path path;
- struct efivarfs_ctx ectx = {
- .ctx = {
- .actor = efivarfs_actor,
- },
- .sb = sfi->sb,
- };
- struct file *file;
- struct super_block *s = sfi->sb;
static bool rescan_done = true;
if (action == PM_HIBERNATION_PREPARE) {
@@ -513,64 +473,15 @@ static int efivarfs_pm_notify(struct notifier_block *nb, unsigned long action,
if (rescan_done)
return NOTIFY_DONE;
- /* ensure single superblock is alive and pin it */
- if (!atomic_inc_not_zero(&s->s_active))
- return NOTIFY_DONE;
-
pr_info("efivarfs: resyncing variable state\n");
- path.dentry = sfi->sb->s_root;
-
- /*
- * do not add SB_KERNMOUNT which a single superblock could
- * expose to userspace and which also causes MNT_INTERNAL, see
- * below
- */
- path.mnt = vfs_kern_mount(&efivarfs_type, 0,
- efivarfs_type.name, NULL);
- if (IS_ERR(path.mnt)) {
- pr_err("efivarfs: internal mount failed\n");
- /*
- * We may be the last pinner of the superblock but
- * calling efivarfs_kill_sb from within the notifier
- * here would deadlock trying to unregister it
- */
- INIT_WORK(&s->destroy_work, efivarfs_deactivate_super_work);
- schedule_work(&s->destroy_work);
- return PTR_ERR(path.mnt);
- }
-
- /* path.mnt now has pin on superblock, so this must be above one */
- atomic_dec(&s->s_active);
-
- file = kernel_file_open(&path, O_RDONLY | O_DIRECTORY | O_NOATIME,
- current_cred());
- /*
- * safe even if last put because no MNT_INTERNAL means this
- * will do delayed deactivate_super and not deadlock
- */
- mntput(path.mnt);
- if (IS_ERR(file))
- return NOTIFY_DONE;
-
rescan_done = true;
/*
* First loop over the directory and verify each entry exists,
* removing it if it doesn't
*/
- file->f_pos = 2; /* skip . and .. */
- do {
- ectx.dentry = NULL;
- iterate_dir(file, &ectx.ctx);
- if (ectx.dentry) {
- pr_info("efivarfs: removing variable %pd\n",
- ectx.dentry);
- simple_recursive_removal(ectx.dentry, NULL);
- dput(ectx.dentry);
- }
- } while (ectx.dentry);
- fput(file);
+ simple_iterate_call(sfi->sb->s_root, NULL, efivarfs_iterate_callback);
/*
* then loop over variables, creating them if there's no matching
@@ -609,8 +520,8 @@ static void efivarfs_kill_sb(struct super_block *sb)
struct efivarfs_fs_info *sfi = sb->s_fs_info;
blocking_notifier_chain_unregister(&efivar_ops_nh, &sfi->nb);
- kill_litter_super(sb);
unregister_pm_notifier(&sfi->pm_nb);
+ kill_litter_super(sb);
kfree(sfi);
}
--
2.43.0
