From a4af51ce229b1e1eab003966dbfebf9d80093a77 Mon Sep 17 00:00:00 2001 From: Kent Overstreet Date: Tue, 6 Feb 2024 21:56:15 -0500 Subject: [PATCH] fs: super_set_uuid() Some weird old filesytems have UUID-like things that we wish to expose as UUIDs, but are smaller; add a length field so that the new FS_IOC_(GET|SET)UUID ioctls can handle them in generic code. And add a helper super_set_uuid(), for setting nonstandard length uuids. Helper is now required for the new FS_IOC_GETUUID ioctl; if super_set_uuid() hasn't been called, the ioctl won't be supported. Reviewed-by: Dave Chinner Signed-off-by: Kent Overstreet Link: https://lore.kernel.org/r/20240207025624.1019754-2-kent.overstreet@linux.dev Signed-off-by: Christian Brauner --- fs/ext4/super.c | 2 +- fs/f2fs/super.c | 2 +- fs/gfs2/ops_fstype.c | 2 +- fs/kernfs/mount.c | 4 +++- fs/ocfs2/super.c | 4 ++-- fs/ubifs/super.c | 2 +- fs/xfs/xfs_mount.c | 2 +- include/linux/fs.h | 9 +++++++++ mm/shmem.c | 4 +++- 9 files changed, 22 insertions(+), 9 deletions(-) diff --git a/fs/ext4/super.c b/fs/ext4/super.c index dcba0f85dfe2..9e28ebd0869a 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -5346,7 +5346,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb) sb->s_qcop = &ext4_qctl_operations; sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ; #endif - memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid)); + super_set_uuid(sb, es->s_uuid, sizeof(es->s_uuid)); INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */ mutex_init(&sbi->s_orphan_lock); diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index d45ab0992ae5..93bcd4e5864e 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -4496,7 +4496,7 @@ try_onemore: sb->s_time_gran = 1; sb->s_flags = (sb->s_flags & ~SB_POSIXACL) | (test_opt(sbi, POSIX_ACL) ? SB_POSIXACL : 0); - memcpy(&sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid)); + super_set_uuid(sb, (void *) raw_super->uuid, sizeof(raw_super->uuid)); sb->s_iflags |= SB_I_CGROUPWB; /* init f2fs-specific super block info */ diff --git a/fs/gfs2/ops_fstype.c b/fs/gfs2/ops_fstype.c index 1281e60be639..572d58e86296 100644 --- a/fs/gfs2/ops_fstype.c +++ b/fs/gfs2/ops_fstype.c @@ -214,7 +214,7 @@ static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf) memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN); memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN); - memcpy(&s->s_uuid, str->sb_uuid, 16); + super_set_uuid(s, str->sb_uuid, 16); } /** diff --git a/fs/kernfs/mount.c b/fs/kernfs/mount.c index 0c93cad0f0ac..e29f4edf9572 100644 --- a/fs/kernfs/mount.c +++ b/fs/kernfs/mount.c @@ -358,7 +358,9 @@ int kernfs_get_tree(struct fs_context *fc) } sb->s_flags |= SB_ACTIVE; - uuid_gen(&sb->s_uuid); + uuid_t uuid; + uuid_gen(&uuid); + super_set_uuid(sb, uuid.b, sizeof(uuid)); down_write(&root->kernfs_supers_rwsem); list_add(&info->node, &info->root->supers); diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c index 6b906424902b..a70aff17d455 100644 --- a/fs/ocfs2/super.c +++ b/fs/ocfs2/super.c @@ -2027,8 +2027,8 @@ static int ocfs2_initialize_super(struct super_block *sb, cbits = le32_to_cpu(di->id2.i_super.s_clustersize_bits); bbits = le32_to_cpu(di->id2.i_super.s_blocksize_bits); sb->s_maxbytes = ocfs2_max_file_offset(bbits, cbits); - memcpy(&sb->s_uuid, di->id2.i_super.s_uuid, - sizeof(di->id2.i_super.s_uuid)); + super_set_uuid(sb, di->id2.i_super.s_uuid, + sizeof(di->id2.i_super.s_uuid)); osb->osb_dx_mask = (1 << (cbits - bbits)) - 1; diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c index 09e270d6ed02..f780729eec06 100644 --- a/fs/ubifs/super.c +++ b/fs/ubifs/super.c @@ -2245,7 +2245,7 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent) goto out_umount; } - import_uuid(&sb->s_uuid, c->uuid); + super_set_uuid(sb, c->uuid, sizeof(c->uuid)); mutex_unlock(&c->umount_mutex); return 0; diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c index aabb25dc3efa..4a46bc44088f 100644 --- a/fs/xfs/xfs_mount.c +++ b/fs/xfs/xfs_mount.c @@ -62,7 +62,7 @@ xfs_uuid_mount( int hole, i; /* Publish UUID in struct super_block */ - uuid_copy(&mp->m_super->s_uuid, uuid); + super_set_uuid(mp->m_super, uuid->b, sizeof(*uuid)); if (xfs_has_nouuid(mp)) return 0; diff --git a/include/linux/fs.h b/include/linux/fs.h index ed5966a70495..acdc56987cb1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1257,6 +1257,7 @@ struct super_block { char s_id[32]; /* Informational name */ uuid_t s_uuid; /* UUID */ + u8 s_uuid_len; /* Default 16, possibly smaller for weird filesystems */ unsigned int s_max_links; @@ -2532,6 +2533,14 @@ extern __printf(2, 3) int super_setup_bdi_name(struct super_block *sb, char *fmt, ...); extern int super_setup_bdi(struct super_block *sb); +static inline void super_set_uuid(struct super_block *sb, const u8 *uuid, unsigned len) +{ + if (WARN_ON(len > sizeof(sb->s_uuid))) + len = sizeof(sb->s_uuid); + sb->s_uuid_len = len; + memcpy(&sb->s_uuid, uuid, len); +} + extern int current_umask(void); extern void ihold(struct inode * inode); diff --git a/mm/shmem.c b/mm/shmem.c index d7c84ff62186..be41955e52da 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -4355,7 +4355,9 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc) #ifdef CONFIG_TMPFS_POSIX_ACL sb->s_flags |= SB_POSIXACL; #endif - uuid_gen(&sb->s_uuid); + uuid_t uuid; + uuid_gen(&uuid); + super_set_uuid(sb, uuid.b, sizeof(uuid)); #ifdef CONFIG_TMPFS_QUOTA if (ctx->seen & SHMEM_SEEN_QUOTA) {