diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2022-08-08 11:10:02 -0700 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-08-08 11:10:02 -0700 |
commit | 2bd5d41e0e9d8e423a0bd446ee174584c8a495fe (patch) | |
tree | 720682607966689b7579344c5e8890f8bc8a6628 /fs/super.c | |
parent | 65512eb0e9e6308ca08110c88a9619a9e5a19aa9 (diff) | |
parent | 247861c325c2e4f5ad3c2f9a77ab9d85d15cbcfc (diff) | |
download | linux-2bd5d41e0e9d8e423a0bd446ee174584c8a495fe.tar.bz2 |
Merge tag 'fuse-update-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:
- Fix an issue with reusing the bdi in case of block based filesystems
- Allow root (in init namespace) to access fuse filesystems in user
namespaces if expicitly enabled with a module param
- Misc fixes
* tag 'fuse-update-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: retire block-device-based superblock on force unmount
vfs: function to prevent re-use of block-device-based superblocks
virtio_fs: Modify format for virtio_fs_direct_access
virtiofs: delete unused parameter for virtio_fs_cleanup_vqs
fuse: Add module param for CAP_SYS_ADMIN access bypassing allow_other
fuse: Remove the control interface for virtio-fs
fuse: ioctl: translate ENOSYS
fuse: limit nsec
fuse: avoid unnecessary spinlock bump
fuse: fix deadlock between atomic O_TRUNC and page invalidation
fuse: write inode in fuse_release()
Diffstat (limited to 'fs/super.c')
-rw-r--r-- | fs/super.c | 33 |
1 files changed, 31 insertions, 2 deletions
diff --git a/fs/super.c b/fs/super.c index 4fca6657f442..734ed584a946 100644 --- a/fs/super.c +++ b/fs/super.c @@ -423,6 +423,35 @@ bool trylock_super(struct super_block *sb) } /** + * retire_super - prevents superblock from being reused + * @sb: superblock to retire + * + * The function marks superblock to be ignored in superblock test, which + * prevents it from being reused for any new mounts. If the superblock has + * a private bdi, it also unregisters it, but doesn't reduce the refcount + * of the superblock to prevent potential races. The refcount is reduced + * by generic_shutdown_super(). The function can not be called + * concurrently with generic_shutdown_super(). It is safe to call the + * function multiple times, subsequent calls have no effect. + * + * The marker will affect the re-use only for block-device-based + * superblocks. Other superblocks will still get marked if this function + * is used, but that will not affect their reusability. + */ +void retire_super(struct super_block *sb) +{ + WARN_ON(!sb->s_bdev); + down_write(&sb->s_umount); + if (sb->s_iflags & SB_I_PERSB_BDI) { + bdi_unregister(sb->s_bdi); + sb->s_iflags &= ~SB_I_PERSB_BDI; + } + sb->s_iflags |= SB_I_RETIRED; + up_write(&sb->s_umount); +} +EXPORT_SYMBOL(retire_super); + +/** * generic_shutdown_super - common helper for ->kill_sb() * @sb: superblock to kill * @@ -1216,7 +1245,7 @@ static int set_bdev_super_fc(struct super_block *s, struct fs_context *fc) static int test_bdev_super_fc(struct super_block *s, struct fs_context *fc) { - return s->s_bdev == fc->sget_key; + return !(s->s_iflags & SB_I_RETIRED) && s->s_bdev == fc->sget_key; } /** @@ -1309,7 +1338,7 @@ EXPORT_SYMBOL(get_tree_bdev); static int test_bdev_super(struct super_block *s, void *data) { - return (void *)s->s_bdev == data; + return !(s->s_iflags & SB_I_RETIRED) && (void *)s->s_bdev == data; } struct dentry *mount_bdev(struct file_system_type *fs_type, |