isofs: Implement fileattr_get for case sensitivity

Upper layers such as NFSD need a way to query whether a
filesystem handles filenames in a case-sensitive manner so
they can provide correct semantics to remote clients. Without
this information, NFS exports of ISO 9660 filesystems cannot
advertise their filename case behavior.

Implement isofs_fileattr_get() to report ISO 9660 case handling
behavior. The 'check=r' (relaxed) mount option enables
case-insensitive lookups and is reported via FS_XFLAG_CASEFOLD.
By default, Joliet extensions operate in relaxed mode while
plain ISO 9660 uses strict (case-sensitive) mode.

Plain ISO 9660 names on the medium are uppercase. When neither
Rock Ridge nor Joliet is in effect, the default 'map=n' option
(and 'map=a') routes lookup and readdir through
isofs_name_translate(), which forces A-Z to a-z. The names
visible to userspace then differ in case from the on-disc form,
so report FS_XFLAG_CASENONPRESERVING in that configuration. Rock
Ridge and Joliet both deliver names as authored, and 'map=o'
emits the raw on-disc name unchanged, so those configurations
remain case-preserving.

Casefolding is a directory property, and the in-tree consumers
(NFSD, ksmbd) issue the query against a directory: NFSD walks
to the parent for non-directory dentries before calling
vfs_fileattr_get(), and ksmbd reports per-share attributes from
the share root. Wire .fileattr_get only on
isofs_dir_inode_operations. The CASEFOLD flag is set in both
fa->fsx_xflags and fa->flags so FS_IOC_FSGETXATTR and
FS_IOC_GETFLAGS agree.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Roland Mainz <roland.mainz@nrubsig.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Link: https://patch.msgid.link/20260507-case-sensitivity-v14-12-e62cc8200435@oracle.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Chuck Lever 2026-05-07 04:53:05 -04:00 committed by Christian Brauner
parent ef14aa143f
commit 7bbd51b1d7
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2 changed files with 19 additions and 0 deletions

View File

@ -14,6 +14,7 @@
#include <linux/gfp.h>
#include <linux/filelock.h>
#include "isofs.h"
#include <linux/fileattr.h>
int isofs_name_translate(struct iso_directory_record *de, char *new, struct inode *inode)
{
@ -267,6 +268,20 @@ static int isofs_readdir(struct file *file, struct dir_context *ctx)
return result;
}
int isofs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
{
struct isofs_sb_info *sbi = ISOFS_SB(dentry->d_sb);
if (sbi->s_check == 'r') {
fa->fsx_xflags |= FS_XFLAG_CASEFOLD;
fa->flags |= FS_CASEFOLD_FL;
}
if (!sbi->s_joliet_level && !sbi->s_rock &&
(sbi->s_mapping == 'n' || sbi->s_mapping == 'a'))
fa->fsx_xflags |= FS_XFLAG_CASENONPRESERVING;
return 0;
}
const struct file_operations isofs_dir_operations =
{
.llseek = generic_file_llseek,
@ -281,6 +296,7 @@ const struct file_operations isofs_dir_operations =
const struct inode_operations isofs_dir_inode_operations =
{
.lookup = isofs_lookup,
.fileattr_get = isofs_fileattr_get,
};

View File

@ -197,6 +197,9 @@ isofs_normalize_block_and_offset(struct iso_directory_record* de,
}
}
struct file_kattr;
int isofs_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
extern const struct inode_operations isofs_dir_inode_operations;
extern const struct file_operations isofs_dir_operations;
extern const struct address_space_operations isofs_symlink_aops;