From: Chuck Lever Add case sensitivity reporting to the existing hfsplus_fileattr_get() function via the FS_XFLAG_CASEFOLD flag. HFS+ always preserves case at rest. Case sensitivity depends on how the volume was formatted: HFSX volumes may be either case-sensitive or case-insensitive, indicated by the HFSPLUS_SB_CASEFOLD superblock flag. FS_XFLAG_CASEFOLD is read-only: FS_XFLAG_RDONLY_MASK ensures FS_IOC_FSSETXATTR strips it. The legacy FS_IOC_SETFLAGS path in hfsplus_fileattr_set() also allows FS_CASEFOLD_FL through its allowlist on case-insensitive volumes so that a chattr read-modify-write cycle does not fail with EOPNOTSUPP. Reviewed-by: Viacheslav Dubeyko Reviewed-by: Roland Mainz Signed-off-by: Chuck Lever --- fs/hfsplus/inode.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/fs/hfsplus/inode.c b/fs/hfsplus/inode.c index d05891ec492e..5565c14b4bf6 100644 --- a/fs/hfsplus/inode.c +++ b/fs/hfsplus/inode.c @@ -740,6 +740,7 @@ int hfsplus_fileattr_get(struct dentry *dentry, struct file_kattr *fa) { struct inode *inode = d_inode(dentry); struct hfsplus_inode_info *hip = HFSPLUS_I(inode); + struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb); unsigned int flags = 0; if (inode->i_flags & S_IMMUTABLE) @@ -748,6 +749,8 @@ int hfsplus_fileattr_get(struct dentry *dentry, struct file_kattr *fa) flags |= FS_APPEND_FL; if (hip->userflags & HFSPLUS_FLG_NODUMP) flags |= FS_NODUMP_FL; + if (test_bit(HFSPLUS_SB_CASEFOLD, &sbi->flags)) + flags |= FS_CASEFOLD_FL; fileattr_fill_flags(fa, flags); @@ -759,13 +762,24 @@ int hfsplus_fileattr_set(struct mnt_idmap *idmap, { struct inode *inode = d_inode(dentry); struct hfsplus_inode_info *hip = HFSPLUS_I(inode); + struct hfsplus_sb_info *sbi = HFSPLUS_SB(inode->i_sb); + unsigned int allowed = FS_IMMUTABLE_FL | FS_APPEND_FL | FS_NODUMP_FL; unsigned int new_fl = 0; if (fileattr_has_fsx(fa)) return -EOPNOTSUPP; + /* + * FS_CASEFOLD_FL reflects HFSPLUS_SB_CASEFOLD, a mount-time + * property. Accept it as a no-op so chattr's RMW round-trip + * succeeds; reject any attempt to enable it on a volume that + * was not formatted case-insensitive. + */ + if (test_bit(HFSPLUS_SB_CASEFOLD, &sbi->flags)) + allowed |= FS_CASEFOLD_FL; + /* don't silently ignore unsupported ext2 flags */ - if (fa->flags & ~(FS_IMMUTABLE_FL|FS_APPEND_FL|FS_NODUMP_FL)) + if (fa->flags & ~allowed) return -EOPNOTSUPP; if (fa->flags & FS_IMMUTABLE_FL) -- 2.53.0