[PATCH 03/19] fs: release anon dev_t in deactivate_locked_super

From: Christoph Hellwig
Date: Wed Sep 13 2023 - 07:11:18 EST

Releasing an anon dev_t is a very common thing when freeing a
super_block, as that's done for basically any not block based file
system (modulo the odd mtd special case). So instead of requiring
a special ->kill_sb helper and a lot of boilerplate in more complicated
file systems, just release the anon dev_t in deactivate_locked_super if
the super_block was using one.

As the freeing is done after the main call to kill_super_notify, this
removes the need for having two slightly different call sites for it.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
block/bdev.c | 1 -
drivers/dax/super.c | 1 -
drivers/dma-buf/dma-buf.c | 1 -
drivers/gpu/drm/drm_drv.c | 1 -
drivers/misc/cxl/api.c | 1 -
drivers/scsi/cxlflash/ocxl_hw.c | 1 -
fs/9p/vfs_super.c | 2 +-
fs/afs/super.c | 2 +-
fs/aio.c | 1 -
fs/anon_inodes.c | 1 -
fs/autofs/inode.c | 4 ++--
fs/btrfs/super.c | 3 ++-
fs/btrfs/tests/btrfs-tests.c | 1 -
fs/ceph/super.c | 2 +-
fs/coda/inode.c | 1 -
fs/ecryptfs/main.c | 3 ++-
fs/erofs/super.c | 4 ++--
fs/fuse/inode.c | 2 +-
fs/fuse/virtio_fs.c | 2 +-
fs/hostfs/hostfs_kern.c | 2 +-
fs/kernfs/mount.c | 2 +-
fs/nfs/super.c | 2 +-
fs/nsfs.c | 1 -
fs/openpromfs/inode.c | 1 -
fs/orangefs/super.c | 2 +-
fs/overlayfs/super.c | 1 -
fs/pipe.c | 1 -
fs/proc/root.c | 4 ++--
fs/smb/client/cifsfs.c | 2 +-
fs/super.c | 22 ++++++++--------------
fs/ubifs/super.c | 3 ++-
fs/vboxsf/super.c | 1 -
include/linux/fs.h | 1 -
kernel/resource.c | 1 -
mm/secretmem.c | 1 -
net/socket.c | 1 -
security/apparmor/apparmorfs.c | 1 -
37 files changed, 30 insertions(+), 53 deletions(-)

diff --git a/block/bdev.c b/block/bdev.c
index f3b13aa1b7d428..9db691401497bb 100644
--- a/block/bdev.c
+++ b/block/bdev.c
@@ -358,7 +358,6 @@ static int bd_init_fs_context(struct fs_context *fc)
static struct file_system_type bd_type = {
.name = "bdev",
.init_fs_context = bd_init_fs_context,
- .kill_sb = kill_anon_super,
};

struct super_block *blockdev_superblock __read_mostly;
diff --git a/drivers/dax/super.c b/drivers/dax/super.c
index 0da9232ea1754b..a9315b7396e68a 100644
--- a/drivers/dax/super.c
+++ b/drivers/dax/super.c
@@ -397,7 +397,6 @@ static int dax_init_fs_context(struct fs_context *fc)
static struct file_system_type dax_fs_type = {
.name = "dax",
.init_fs_context = dax_init_fs_context,
- .kill_sb = kill_anon_super,
};

static int dax_test(struct inode *inode, void *data)
diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index 21916bba77d58b..7313e99f6e8ea5 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -125,7 +125,6 @@ static int dma_buf_fs_init_context(struct fs_context *fc)
static struct file_system_type dma_buf_fs_type = {
.name = "dmabuf",
.init_fs_context = dma_buf_fs_init_context,
- .kill_sb = kill_anon_super,
};

static int dma_buf_mmap_internal(struct file *file, struct vm_area_struct *vma)
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 3eda026ffac6a9..83676229cbe233 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -530,7 +530,6 @@ static struct file_system_type drm_fs_type = {
.name = "drm",
.owner = THIS_MODULE,
.init_fs_context = drm_fs_init_fs_context,
- .kill_sb = kill_anon_super,
};

static struct inode *drm_fs_inode_new(void)
diff --git a/drivers/misc/cxl/api.c b/drivers/misc/cxl/api.c
index d85c5653086357..05b40076a0b481 100644
--- a/drivers/misc/cxl/api.c
+++ b/drivers/misc/cxl/api.c
@@ -44,7 +44,6 @@ static struct file_system_type cxl_fs_type = {
.name = "cxl",
.owner = THIS_MODULE,
.init_fs_context = cxl_fs_init_fs_context,
- .kill_sb = kill_anon_super,
};


diff --git a/drivers/scsi/cxlflash/ocxl_hw.c b/drivers/scsi/cxlflash/ocxl_hw.c
index 6542818e595a64..20f22610b104df 100644
--- a/drivers/scsi/cxlflash/ocxl_hw.c
+++ b/drivers/scsi/cxlflash/ocxl_hw.c
@@ -43,7 +43,6 @@ static struct file_system_type ocxlflash_fs_type = {
.name = "ocxlflash",
.owner = THIS_MODULE,
.init_fs_context = ocxlflash_fs_init_fs_context,
- .kill_sb = kill_anon_super,
};

/*
diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c
index 73db55c050bf10..9e60eddf5179ed 100644
--- a/fs/9p/vfs_super.c
+++ b/fs/9p/vfs_super.c
@@ -217,7 +217,7 @@ static void v9fs_kill_super(struct super_block *s)

p9_debug(P9_DEBUG_VFS, " %p\n", s);

- kill_anon_super(s);
+ generic_shutdown_super(s);

v9fs_session_cancel(v9ses);
v9fs_session_close(v9ses);
diff --git a/fs/afs/super.c b/fs/afs/super.c
index 95d713074dc813..754b9828233497 100644
--- a/fs/afs/super.c
+++ b/fs/afs/super.c
@@ -544,7 +544,7 @@ static void afs_kill_super(struct super_block *sb)
*/
if (as->volume)
rcu_assign_pointer(as->volume->sb, NULL);
- kill_anon_super(sb);
+ generic_shutdown_super(sb);
if (as->volume)
afs_deactivate_volume(as->volume);
afs_destroy_sbi(as);
diff --git a/fs/aio.c b/fs/aio.c
index a4c2a6bac72ce9..de56e4a880debe 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -293,7 +293,6 @@ static int __init aio_setup(void)
static struct file_system_type aio_fs = {
.name = "aio",
.init_fs_context = aio_init_fs_context,
- .kill_sb = kill_anon_super,
};
aio_mnt = kern_mount(&aio_fs);
if (IS_ERR(aio_mnt))
diff --git a/fs/anon_inodes.c b/fs/anon_inodes.c
index 24192a7667edf7..9c670bbe0f62ce 100644
--- a/fs/anon_inodes.c
+++ b/fs/anon_inodes.c
@@ -52,7 +52,6 @@ static int anon_inodefs_init_fs_context(struct fs_context *fc)
static struct file_system_type anon_inode_fs_type = {
.name = "anon_inodefs",
.init_fs_context = anon_inodefs_init_fs_context,
- .kill_sb = kill_anon_super,
};

static struct inode *anon_inode_make_secure_inode(
diff --git a/fs/autofs/inode.c b/fs/autofs/inode.c
index 2b49662ed237de..c3b64799155840 100644
--- a/fs/autofs/inode.c
+++ b/fs/autofs/inode.c
@@ -44,7 +44,7 @@ void autofs_kill_sb(struct super_block *sb)
/*
* In the event of a failure in get_sb_nodev the superblock
* info is not present so nothing else has been setup, so
- * just call kill_anon_super when we are called from
+ * just call generic_shutdown_super when we are called from
* deactivate_super.
*/
if (sbi) {
@@ -54,7 +54,7 @@ void autofs_kill_sb(struct super_block *sb)
}

pr_debug("shutting down\n");
- kill_litter_super(sb);
+ generic_shutdown_super(sb);
if (sbi)
kfree_rcu(sbi, rcu);
}
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 09bfe68d2ea3fc..01b86bd4eae8dc 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -2141,7 +2141,8 @@ static int btrfs_statfs(struct dentry *dentry, struct kstatfs *buf)
static void btrfs_kill_super(struct super_block *sb)
{
struct btrfs_fs_info *fs_info = btrfs_sb(sb);
- kill_anon_super(sb);
+
+ generic_shutdown_super(sb);
btrfs_free_fs_info(fs_info);
}

diff --git a/fs/btrfs/tests/btrfs-tests.c b/fs/btrfs/tests/btrfs-tests.c
index ca09cf9afce800..c30280376fc32e 100644
--- a/fs/btrfs/tests/btrfs-tests.c
+++ b/fs/btrfs/tests/btrfs-tests.c
@@ -48,7 +48,6 @@ static int btrfs_test_init_fs_context(struct fs_context *fc)
static struct file_system_type test_type = {
.name = "btrfs_test_fs",
.init_fs_context = btrfs_test_init_fs_context,
- .kill_sb = kill_anon_super,
};

struct inode *btrfs_new_test_inode(void)
diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index 2d7f5a8d4a9260..7feef0b35b97b5 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -1557,7 +1557,7 @@ static void ceph_kill_sb(struct super_block *s)
}

mdsc->stopping = CEPH_MDSC_STOPPING_FLUSHED;
- kill_anon_super(s);
+ generic_shutdown_super(s);

fsc->client->extra_mon_dispatch = NULL;
ceph_fs_debugfs_cleanup(fsc);
diff --git a/fs/coda/inode.c b/fs/coda/inode.c
index 0c7c2528791ebc..2d4ee3c7e8654b 100644
--- a/fs/coda/inode.c
+++ b/fs/coda/inode.c
@@ -325,7 +325,6 @@ struct file_system_type coda_fs_type = {
.owner = THIS_MODULE,
.name = "coda",
.mount = coda_mount,
- .kill_sb = kill_anon_super,
.fs_flags = FS_BINARY_MOUNTDATA,
};
MODULE_ALIAS_FS("coda");
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index 2dc927ba067fec..d99b2311759166 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -625,7 +625,8 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
static void ecryptfs_kill_block_super(struct super_block *sb)
{
struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb);
- kill_anon_super(sb);
+
+ generic_shutdown_super(sb);
if (!sb_info)
return;
ecryptfs_destroy_mount_crypt_stat(&sb_info->mount_crypt_stat);
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 44a24d573f1fd3..07c36ccf454e53 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -878,12 +878,12 @@ static void erofs_kill_sb(struct super_block *sb)

/* pseudo mount for anon inodes */
if (sb->s_flags & SB_KERNMOUNT) {
- kill_anon_super(sb);
+ generic_shutdown_super(sb);
return;
}

if (erofs_is_fscache_mode(sb))
- kill_anon_super(sb);
+ generic_shutdown_super(sb);
else
kill_block_super(sb);

diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 2e4eb7cf26fb33..42523edb32fd53 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -1840,7 +1840,7 @@ EXPORT_SYMBOL(fuse_mount_destroy);
static void fuse_kill_sb_anon(struct super_block *sb)
{
fuse_sb_destroy(sb);
- kill_anon_super(sb);
+ generic_shutdown_super(sb);
fuse_mount_destroy(get_fuse_mount_super(sb));
}

diff --git a/fs/fuse/virtio_fs.c b/fs/fuse/virtio_fs.c
index 5f1be1da92ce94..0a0d593e5a9c79 100644
--- a/fs/fuse/virtio_fs.c
+++ b/fs/fuse/virtio_fs.c
@@ -1398,7 +1398,7 @@ static void virtio_kill_sb(struct super_block *sb)
if (last)
virtio_fs_conn_destroy(fm);
}
- kill_anon_super(sb);
+ generic_shutdown_super(sb);
fuse_mount_destroy(fm);
}

diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index dc5a5cea5fae41..97f3c9709418c9 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -981,7 +981,7 @@ static struct dentry *hostfs_read_sb(struct file_system_type *type,

static void hostfs_kill_sb(struct super_block *s)
{
- kill_anon_super(s);
+ generic_shutdown_super(s);
kfree(s->s_fs_info);
}

diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c
index c4bf26142eec9b..772d059d4054ec 100644
--- a/fs/kernfs/mount.c
+++ b/fs/kernfs/mount.c
@@ -399,7 +399,7 @@ void kernfs_kill_sb(struct super_block *sb)
* Remove the superblock from fs_supers/s_instances
* so we can't find it, before freeing kernfs_super_info.
*/
- kill_anon_super(sb);
+ generic_shutdown_super(sb);
kfree(info);
}

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 0d6473cb00cb3e..29d6a55b9d400d 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -1341,7 +1341,7 @@ void nfs_kill_super(struct super_block *s)
struct nfs_server *server = NFS_SB(s);

nfs_sysfs_move_sb_to_server(server);
- kill_anon_super(s);
+ generic_shutdown_super(s);

nfs_fscache_release_super_cookie(s);

diff --git a/fs/nsfs.c b/fs/nsfs.c
index 647a22433bd8a9..d5fb7c00fe21f1 100644
--- a/fs/nsfs.c
+++ b/fs/nsfs.c
@@ -277,7 +277,6 @@ static int nsfs_init_fs_context(struct fs_context *fc)
static struct file_system_type nsfs = {
.name = "nsfs",
.init_fs_context = nsfs_init_fs_context,
- .kill_sb = kill_anon_super,
};

void __init nsfs_init(void)
diff --git a/fs/openpromfs/inode.c b/fs/openpromfs/inode.c
index b2457cb97fa008..3b51dd926d11c8 100644
--- a/fs/openpromfs/inode.c
+++ b/fs/openpromfs/inode.c
@@ -427,7 +427,6 @@ static struct file_system_type openprom_fs_type = {
.owner = THIS_MODULE,
.name = "openpromfs",
.init_fs_context = openpromfs_init_fs_context,
- .kill_sb = kill_anon_super,
};
MODULE_ALIAS_FS("openpromfs");

diff --git a/fs/orangefs/super.c b/fs/orangefs/super.c
index 5254256a224d7a..42cb3e9b1effee 100644
--- a/fs/orangefs/super.c
+++ b/fs/orangefs/super.c
@@ -602,7 +602,7 @@ void orangefs_kill_sb(struct super_block *sb)
gossip_debug(GOSSIP_SUPER_DEBUG, "orangefs_kill_sb: called\n");

/* provided sb cleanup */
- kill_anon_super(sb);
+ generic_shutdown_super(sb);

if (!ORANGEFS_SB(sb)) {
mutex_lock(&orangefs_request_mutex);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index def266b5e2a33b..194cf18787496d 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -1507,7 +1507,6 @@ struct file_system_type ovl_fs_type = {
.init_fs_context = ovl_init_fs_context,
.parameters = ovl_parameter_spec,
.fs_flags = FS_USERNS_MOUNT,
- .kill_sb = kill_anon_super,
};
MODULE_ALIAS_FS("overlay");

diff --git a/fs/pipe.c b/fs/pipe.c
index 6c1a9b1db9076c..858e8b19d78527 100644
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -1439,7 +1439,6 @@ static int pipefs_init_fs_context(struct fs_context *fc)
static struct file_system_type pipe_fs_type = {
.name = "pipefs",
.init_fs_context = pipefs_init_fs_context,
- .kill_sb = kill_anon_super,
};

#ifdef CONFIG_SYSCTL
diff --git a/fs/proc/root.c b/fs/proc/root.c
index 9191248f2dacb4..2282366449ac0b 100644
--- a/fs/proc/root.c
+++ b/fs/proc/root.c
@@ -262,14 +262,14 @@ static void proc_kill_sb(struct super_block *sb)
struct proc_fs_info *fs_info = proc_sb_info(sb);

if (!fs_info) {
- kill_anon_super(sb);
+ generic_shutdown_super(sb);
return;
}

dput(fs_info->proc_self);
dput(fs_info->proc_thread_self);

- kill_anon_super(sb);
+ generic_shutdown_super(sb);
put_pid_ns(fs_info->pid_ns);
kfree(fs_info);
}
diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index 22869cda13565e..fb792acffeca37 100644
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -302,7 +302,7 @@ static void cifs_kill_sb(struct super_block *sb)
cifs_sb->root = NULL;
}

- kill_anon_super(sb);
+ generic_shutdown_super(sb);
cifs_umount(cifs_sb);
}

diff --git a/fs/super.c b/fs/super.c
index ab234e6af48605..bbe55f0651cca4 100644
--- a/fs/super.c
+++ b/fs/super.c
@@ -438,10 +438,6 @@ static void kill_super_notify(struct super_block *sb)
{
lockdep_assert_not_held(&sb->s_umount);

- /* already notified earlier */
- if (sb->s_flags & SB_DEAD)
- return;
-
/*
* Remove it from @fs_supers so it isn't found by new
* sget{_fc}() walkers anymore. Any concurrent mounter still
@@ -491,6 +487,13 @@ void deactivate_locked_super(struct super_block *s)

kill_super_notify(s);

+ /*
+ * If the super_block was using an anon dev_t, release it now that we've
+ * notified everyone that the super_block is going away.
+ */
+ if (s->s_dev && MAJOR(s->s_dev) == 0)
+ free_anon_bdev(s->s_dev);
+
/*
* Since list_lru_destroy() may sleep, we cannot call it from
* put_super(), where we hold the sb_lock. Therefore we destroy
@@ -1291,20 +1294,11 @@ int set_anon_super(struct super_block *s, void *data)
}
EXPORT_SYMBOL(set_anon_super);

-void kill_anon_super(struct super_block *sb)
-{
- dev_t dev = sb->s_dev;
- generic_shutdown_super(sb);
- kill_super_notify(sb);
- free_anon_bdev(dev);
-}
-EXPORT_SYMBOL(kill_anon_super);
-
void kill_litter_super(struct super_block *sb)
{
if (sb->s_root)
d_genocide(sb->s_root);
- kill_anon_super(sb);
+ generic_shutdown_super(sb);
}
EXPORT_SYMBOL(kill_litter_super);

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index b08fb28d16b55b..6527175591a729 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -2350,7 +2350,8 @@ static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
static void kill_ubifs_super(struct super_block *s)
{
struct ubifs_info *c = s->s_fs_info;
- kill_anon_super(s);
+
+ generic_shutdown_super(s);
kfree(c);
}

diff --git a/fs/vboxsf/super.c b/fs/vboxsf/super.c
index 1fb8f4df60cbb3..aa7e627bf9bd4b 100644
--- a/fs/vboxsf/super.c
+++ b/fs/vboxsf/super.c
@@ -450,7 +450,6 @@ static struct file_system_type vboxsf_fs_type = {
.owner = THIS_MODULE,
.name = "vboxsf",
.init_fs_context = vboxsf_init_fs_context,
- .kill_sb = kill_anon_super
};

/* Module initialization/finalization handlers */
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 4aeb3fa1192771..129b8c0c83960b 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2382,7 +2382,6 @@ extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path);
void retire_super(struct super_block *sb);
void generic_shutdown_super(struct super_block *sb);
void kill_block_super(struct super_block *sb);
-void kill_anon_super(struct super_block *sb);
void kill_litter_super(struct super_block *sb);
void deactivate_super(struct super_block *sb);
void deactivate_locked_super(struct super_block *sb);
diff --git a/kernel/resource.c b/kernel/resource.c
index b1763b2fd7ef3e..fde412517ef0cc 100644
--- a/kernel/resource.c
+++ b/kernel/resource.c
@@ -1979,7 +1979,6 @@ static struct file_system_type iomem_fs_type = {
.name = "iomem",
.owner = THIS_MODULE,
.init_fs_context = iomem_fs_init_fs_context,
- .kill_sb = kill_anon_super,
};

static int __init iomem_init_inode(void)
diff --git a/mm/secretmem.c b/mm/secretmem.c
index 3afb5ad701e14a..74e1cdb1317cd7 100644
--- a/mm/secretmem.c
+++ b/mm/secretmem.c
@@ -275,7 +275,6 @@ static int secretmem_init_fs_context(struct fs_context *fc)
static struct file_system_type secretmem_fs = {
.name = "secretmem",
.init_fs_context = secretmem_init_fs_context,
- .kill_sb = kill_anon_super,
};

static int __init secretmem_init(void)
diff --git a/net/socket.c b/net/socket.c
index c8b08b32f097ec..a137b08a7d94d1 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -425,7 +425,6 @@ static struct vfsmount *sock_mnt __read_mostly;
static struct file_system_type sock_fs_type = {
.name = "sockfs",
.init_fs_context = sockfs_init_fs_context,
- .kill_sb = kill_anon_super,
};

/*
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index bd6a910f65282a..eceb5443842cdf 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -198,7 +198,6 @@ static struct file_system_type aafs_ops = {
.owner = THIS_MODULE,
.name = AAFS_NAME,
.init_fs_context = apparmorfs_init_fs_context,
- .kill_sb = kill_anon_super,
};

/**
--
2.39.2