Exposing case folding behavior

index 13cdb31a3e94..a73de0e0ecac 100644
@@ -21,6 +21,9 @@
 void fileattr_fill_xflags(struct file_kattr *fa, u32 xflags)
 {
 	memset(fa, 0, sizeof(*fa));
+	/* Default: POSIX semantics (case-sensitive, case-preserving) */
+	fa->case_insensitive = false;
+	fa->case_preserving = true;
 	fa->fsx_valid = true;
 	fa->fsx_xflags = xflags;
 	if (fa->fsx_xflags & FS_XFLAG_IMMUTABLE)

@@ -51,6 +54,9 @@ EXPORT_SYMBOL(fileattr_fill_xflags);
 void fileattr_fill_flags(struct file_kattr *fa, u32 flags)
 {
 	memset(fa, 0, sizeof(*fa));
+	/* Default: POSIX semantics (case-sensitive, case-preserving) */
+	fa->case_insensitive = false;
+	fa->case_preserving = true;
 	fa->flags_valid = true;
 	fa->flags = flags;
 	if (fa->flags & FS_SYNC_FL)

@@ -84,6 +90,10 @@ int vfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
 	struct inode *inode = d_inode(dentry);
 	int error;
 
+	/* Default: POSIX semantics (case-sensitive, case-preserving) */
+	fa->case_insensitive = false;
+	fa->case_preserving = true;
+
 	if (!inode->i_op->fileattr_get)
 		return -ENOIOCTLCMD;
 

index f89dcfad3f8f..cfd4d3973716 100644
@@ -51,6 +51,9 @@ struct file_kattr {
 	/* selectors: */
 	bool	flags_valid:1;
 	bool	fsx_valid:1;
+	/* case sensitivity behavior: */
+	bool	case_insensitive:1;
+	bool	case_preserving:1;
 };
 
 int copy_fsxattr_to_user(const struct file_kattr *fa, struct fsxattr __user *ufa);

index d3e426de5f01..38da08d8fec4 100644
@@ -10,6 +10,8 @@
 #include <linux/fs_context.h>
 #include <linux/fs_parser.h>
 
+struct file_kattr;
+
 /*
  * vfat shortname flags
  */

@@ -407,6 +409,7 @@ extern void fat_truncate_blocks(struct inode *inode, loff_t offset);
 extern int fat_getattr(struct mnt_idmap *idmap,
 		       const struct path *path, struct kstat *stat,
 		       u32 request_mask, unsigned int flags);
+extern int fat_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
 extern int fat_file_fsync(struct file *file, loff_t start, loff_t end,
 			  int datasync);
 

index 4fc49a614fb8..d26dc792611a 100644
@@ -16,6 +16,7 @@
 #include <linux/fsnotify.h>
 #include <linux/security.h>
 #include <linux/falloc.h>
+#include <linux/fileattr.h>
 #include "fat.h"
 
 static long fat_fallocate(struct file *file, int mode,

@@ -395,6 +396,22 @@ void fat_truncate_blocks(struct inode *inode, loff_t offset)
 	fat_flush_inodes(inode->i_sb, inode, NULL);
 }
 
+int fat_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	struct msdos_sb_info *sbi = MSDOS_SB(dentry->d_sb);
+
+	/*
+	 * FAT filesystems do not preserve case: stored names are
+	 * uppercased. They are case-insensitive by default, but
+	 * MSDOS supports a 'nocase' mount option for case-sensitive
+	 * behavior.
+	 */
+	fa->case_insensitive = !sbi->options.nocase;
+	fa->case_preserving = false;
+	return 0;
+}
+EXPORT_SYMBOL_GPL(fat_fileattr_get);
+
 int fat_getattr(struct mnt_idmap *idmap, const struct path *path,
 		struct kstat *stat, u32 request_mask, unsigned int flags)
 {

@@ -574,5 +591,6 @@ EXPORT_SYMBOL_GPL(fat_setattr);
 const struct inode_operations fat_file_inode_operations = {
 	.setattr	= fat_setattr,
 	.getattr	= fat_getattr,
+	.fileattr_get	= fat_fileattr_get,
 	.update_time	= fat_update_time,
 };

index 0b920ee40a7f..380add5c6c66 100644
@@ -640,6 +640,7 @@ static const struct inode_operations msdos_dir_inode_operations = {
 	.rename		= msdos_rename,
 	.setattr	= fat_setattr,
 	.getattr	= fat_getattr,
+	.fileattr_get	= fat_fileattr_get,
 	.update_time	= fat_update_time,
 };
 

index 5dbc4cbb8fce..6cf513f97afa 100644
@@ -1180,6 +1180,7 @@ static const struct inode_operations vfat_dir_inode_operations = {
 	.rename		= vfat_rename2,
 	.setattr	= fat_setattr,
 	.getattr	= fat_getattr,
+	.fileattr_get	= fat_fileattr_get,
 	.update_time	= fat_update_time,
 };
 

index 176fef62574c..11c782a28843 100644
@@ -468,6 +468,8 @@ int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
 		  struct kstat *stat, unsigned int request_mask,
 		  unsigned int query_flags);
+struct file_kattr;
+int exfat_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
 int exfat_file_fsync(struct file *file, loff_t start, loff_t end, int datasync);
 long exfat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg);
 long exfat_compat_ioctl(struct file *filp, unsigned int cmd,

index 536c8078f0c1..0fda71b3e838 100644
@@ -12,6 +12,7 @@
 #include <linux/security.h>
 #include <linux/msdos_fs.h>
 #include <linux/writeback.h>
+#include <linux/fileattr.h>
 
 #include "exfat_raw.h"
 #include "exfat_fs.h"

@@ -281,6 +282,17 @@ int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
 	return 0;
 }
 
+int exfat_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	/*
+	 * exFAT is always case-insensitive (using upcase table) and
+	 * always preserves case at rest.
+	 */
+	fa->case_insensitive = true;
+	fa->case_preserving = true;
+	return 0;
+}
+
 int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
 		  struct iattr *attr)
 {

@@ -775,6 +787,7 @@ const struct file_operations exfat_file_operations = {
 };
 
 const struct inode_operations exfat_file_inode_operations = {
-	.setattr     = exfat_setattr,
-	.getattr     = exfat_getattr,
+	.setattr	= exfat_setattr,
+	.getattr	= exfat_getattr,
+	.fileattr_get	= exfat_fileattr_get,
 };

index dfe957493d49..a3a854ddc83a 100644
@@ -1323,4 +1323,5 @@ const struct inode_operations exfat_dir_inode_operations = {
 	.rename		= exfat_rename,
 	.setattr	= exfat_setattr,
 	.getattr	= exfat_getattr,
+	.fileattr_get	= exfat_fileattr_get,
 };

index 2e7b2e566ebe..cc37a9386d93 100644
@@ -146,6 +146,28 @@ long ntfs_compat_ioctl(struct file *filp, u32 cmd, unsigned long arg)
 }
 #endif
 
+/*
+ * ntfs_fileattr_get - inode_operations::fileattr_get
+ */
+int ntfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	struct inode *inode = d_inode(dentry);
+	struct ntfs_sb_info *sbi = inode->i_sb->s_fs_info;
+
+	/* Avoid any operation if inode is bad. */
+	if (unlikely(is_bad_ni(ntfs_i(inode))))
+		return -EINVAL;
+
+	/*
+	 * NTFS preserves case. Case sensitivity depends on mount options:
+	 * with "nocase" mount option, NTFS is case-insensitive;
+	 * otherwise it is case-sensitive.
+	 */
+	fa->case_insensitive = sbi->options && sbi->options->nocase;
+	fa->case_preserving = true;
+	return 0;
+}
+
 /*
  * ntfs_getattr - inode_operations::getattr
  */

@@ -1460,6 +1482,7 @@ const struct inode_operations ntfs_file_inode_operations = {
 	.get_acl	= ntfs_get_acl,
 	.set_acl	= ntfs_set_acl,
 	.fiemap		= ntfs_fiemap,
+	.fileattr_get	= ntfs_fileattr_get,
 };
 
 const struct file_operations ntfs_file_operations = {

index 0a9ac5efeb67..205083e8a6e0 100644
@@ -2089,6 +2089,7 @@ const struct inode_operations ntfs_link_inode_operations = {
 	.get_link	= ntfs_get_link,
 	.setattr	= ntfs_setattr,
 	.listxattr	= ntfs_listxattr,
+	.fileattr_get	= ntfs_fileattr_get,
 };
 
 const struct address_space_operations ntfs_aops = {

index 3b24ca02de61..d09414711016 100644
@@ -519,6 +519,7 @@ const struct inode_operations ntfs_dir_inode_operations = {
 	.getattr	= ntfs_getattr,
 	.listxattr	= ntfs_listxattr,
 	.fiemap		= ntfs_fiemap,
+	.fileattr_get	= ntfs_fileattr_get,
 };
 
 const struct inode_operations ntfs_special_inode_operations = {

@@ -527,6 +528,7 @@ const struct inode_operations ntfs_special_inode_operations = {
 	.listxattr	= ntfs_listxattr,
 	.get_acl	= ntfs_get_acl,
 	.set_acl	= ntfs_set_acl,
+	.fileattr_get	= ntfs_fileattr_get,
 };
 
 const struct dentry_operations ntfs_dentry_ops = {

index a4559c9f64e6..a578b75f31fc 100644
@@ -504,6 +504,7 @@ extern const struct file_operations ntfs_dir_operations;
 extern const struct file_operations ntfs_legacy_dir_operations;
 
 /* Globals from file.c */
+int ntfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
 int ntfs_getattr(struct mnt_idmap *idmap, const struct path *path,
 		 struct kstat *stat, u32 request_mask, u32 flags);
 int ntfs_setattr(struct mnt_idmap *idmap, struct dentry *dentry,

index 86a6b317b474..552156896105 100644
@@ -321,4 +321,5 @@ const struct inode_operations hfs_dir_inode_operations = {
 	.rmdir		= hfs_remove,
 	.rename		= hfs_rename,
 	.setattr	= hfs_inode_setattr,
+	.fileattr_get	= hfs_fileattr_get,
 };

index e94dbc04a1e4..a25cdda8ab34 100644
@@ -177,6 +177,8 @@ extern int hfs_get_block(struct inode *inode, sector_t block,
 extern const struct address_space_operations hfs_aops;
 extern const struct address_space_operations hfs_btree_aops;
 
+struct file_kattr;
+int hfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
 int hfs_write_begin(const struct kiocb *iocb, struct address_space *mapping,
 		    loff_t pos, unsigned int len, struct folio **foliop,
 		    void **fsdata);

index 524db1389737..06429decc1d8 100644
@@ -18,6 +18,7 @@
 #include <linux/uio.h>
 #include <linux/xattr.h>
 #include <linux/blkdev.h>
+#include <linux/fileattr.h>
 
 #include "hfs_fs.h"
 #include "btree.h"

@@ -698,6 +699,17 @@ static int hfs_file_fsync(struct file *filp, loff_t start, loff_t end,
 	return ret;
 }
 
+int hfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	/*
+	 * HFS is always case-insensitive (using Mac OS Roman case
+	 * folding) and always preserves case at rest.
+	 */
+	fa->case_insensitive = true;
+	fa->case_preserving = true;
+	return 0;
+}
+
 static const struct file_operations hfs_file_operations = {
 	.llseek		= generic_file_llseek,
 	.read_iter	= generic_file_read_iter,

@@ -714,4 +726,5 @@ static const struct inode_operations hfs_file_inode_operations = {
 	.lookup		= hfs_file_lookup,
 	.setattr	= hfs_inode_setattr,
 	.listxattr	= generic_listxattr,
+	.fileattr_get	= hfs_fileattr_get,
 };

index 7ae6745ca7ae..0ce9561c0f18 100644
@@ -694,6 +694,7 @@ 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)

@@ -705,6 +706,14 @@ int hfsplus_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
 
 	fileattr_fill_flags(fa, flags);
 
+	/*
+	 * HFS+ always preserves case. Case sensitivity depends on how
+	 * the filesystem was formatted: HFSX volumes may be either
+	 * case-sensitive or case-insensitive.
+	 */
+	fa->case_insensitive = test_bit(HFSPLUS_SB_CASEFOLD, &sbi->flags);
+	fa->case_preserving = true;
+
 	return 0;
 }
 

index 7ce0fc40aec2..653035017c7f 100644
@@ -996,6 +996,14 @@ int ext4_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
 	if (ext4_has_feature_project(inode->i_sb))
 		fa->fsx_projid = from_kprojid(&init_user_ns, ei->i_projid);
 
+	/*
+	 * ext4 always preserves case. If this inode is a casefolded
+	 * directory, report case-insensitive; otherwise report
+	 * case-sensitive (standard POSIX behavior).
+	 */
+	fa->case_insensitive = IS_CASEFOLDED(inode);
+	fa->case_preserving = true;
+
 	return 0;
 }
 

index 59eaad774371..97314fcb7732 100644
@@ -516,6 +516,13 @@ xfs_fileattr_get(
 	xfs_fill_fsxattr(ip, XFS_DATA_FORK, fa);
 	xfs_iunlock(ip, XFS_ILOCK_SHARED);
 
+	/*
+	 * XFS is case-sensitive by default, but can be formatted with
+	 * ASCII case-insensitive mode enabled.
+	 */
+	fa->case_insensitive = xfs_has_asciici(ip->i_mount);
+	fa->case_preserving = true;
+
 	return 0;
 }
 

index d9664634144d..407afe60ee6c 100644
@@ -30,6 +30,7 @@
 #include <linux/xattr.h>
 #include <linux/mm.h>
 #include <linux/key-type.h>
+#include <linux/fileattr.h>
 #include <uapi/linux/magic.h>
 #include <net/ipv6.h>
 #include "cifsfs.h"

@@ -1193,6 +1194,21 @@ struct file_system_type smb3_fs_type = {
 MODULE_ALIAS_FS("smb3");
 MODULE_ALIAS("smb3");
 
+static int cifs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	struct cifs_sb_info *cifs_sb = CIFS_SB(dentry->d_sb);
+	struct cifs_tcon *tcon = cifs_sb_master_tcon(cifs_sb);
+
+	/*
+	 * CIFS/SMB servers are typically case-insensitive but
+	 * case-preserving. The nocase mount option reflects what
+	 * the client expects from the server.
+	 */
+	fa->case_insensitive = tcon->nocase;
+	fa->case_preserving = true;
+	return 0;
+}
+
 const struct inode_operations cifs_dir_inode_ops = {
 	.create = cifs_create,
 	.atomic_open = cifs_atomic_open,

@@ -1210,6 +1226,7 @@ const struct inode_operations cifs_dir_inode_ops = {
 	.listxattr = cifs_listxattr,
 	.get_acl = cifs_get_acl,
 	.set_acl = cifs_set_acl,
+	.fileattr_get = cifs_fileattr_get,
 };
 
 const struct inode_operations cifs_file_inode_ops = {

@@ -1220,6 +1237,7 @@ const struct inode_operations cifs_file_inode_ops = {
 	.fiemap = cifs_fiemap,
 	.get_acl = cifs_get_acl,
 	.set_acl = cifs_set_acl,
+	.fileattr_get = cifs_fileattr_get,
 };
 
 const char *cifs_get_link(struct dentry *dentry, struct inode *inode,

@@ -1254,6 +1272,7 @@ const struct inode_operations cifs_symlink_inode_ops = {
 	.setattr = cifs_setattr,
 	.permission = cifs_permission,
 	.listxattr = cifs_listxattr,
+	.fileattr_get = cifs_fileattr_get,
 };
 
 /*

index 2aaea9c98c2c..da437d89e14a 100644
@@ -935,13 +935,18 @@ static int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *mntfh, str
 
 	/* Get some general file system info */
 	if (server->namelen == 0) {
-		struct nfs_pathconf pathinfo;
+		struct nfs_pathconf pathinfo = { };
 
 		pathinfo.fattr = fattr;
 		nfs_fattr_init(fattr);
 
-		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0)
+		if (clp->rpc_ops->pathconf(server, mntfh, &pathinfo) >= 0) {
 			server->namelen = pathinfo.max_namelen;
+			if (pathinfo.case_insensitive)
+				server->caps |= NFS_CAP_CASE_INSENSITIVE;
+			if (pathinfo.case_preserving)
+				server->caps |= NFS_CAP_CASE_PRESERVING;
+		}
 	}
 
 	if (clp->rpc_ops->discover_trunking != NULL &&

index 84049f3cd340..268b254bf0c7 100644
@@ -41,6 +41,7 @@
 #include <linux/freezer.h>
 #include <linux/uaccess.h>
 #include <linux/iversion.h>
+#include <linux/fileattr.h>
 
 #include "nfs4_fs.h"
 #include "callback.h"

@@ -1100,6 +1101,23 @@ int nfs_getattr(struct mnt_idmap *idmap, const struct path *path,
 }
 EXPORT_SYMBOL_GPL(nfs_getattr);
 
+/**
+ * nfs_fileattr_get - Retrieve file attributes
+ * @dentry: object to query
+ * @fa: file attributes to fill in
+ *
+ * Return: 0 on success
+ */
+int nfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	struct inode *inode = d_inode(dentry);
+
+	fa->case_insensitive = nfs_server_capable(inode, NFS_CAP_CASE_INSENSITIVE);
+	fa->case_preserving = nfs_server_capable(inode, NFS_CAP_CASE_PRESERVING);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nfs_fileattr_get);
+
 static void nfs_init_lock_context(struct nfs_lock_context *l_ctx)
 {
 	refcount_set(&l_ctx->count, 1);

index 2e596244799f..a843e076aad7 100644
@@ -453,6 +453,9 @@ extern void nfs_set_cache_invalid(struct inode *inode, unsigned long flags);
 extern bool nfs_check_cache_invalid(struct inode *, unsigned long);
 extern int nfs_wait_bit_killable(struct wait_bit_key *key, int mode);
 
+struct file_kattr;
+int nfs_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
+
 #if IS_ENABLED(CONFIG_NFS_LOCALIO)
 /* localio.c */
 struct nfs_local_dio {

index 1181f9cc6dbd..60344a83f400 100644
@@ -1048,6 +1048,7 @@ static const struct inode_operations nfs3_dir_inode_operations = {
 	.permission	= nfs_permission,
 	.getattr	= nfs_getattr,
 	.setattr	= nfs_setattr,
+	.fileattr_get	= nfs_fileattr_get,
 #ifdef CONFIG_NFS_V3_ACL
 	.listxattr	= nfs3_listxattr,
 	.get_inode_acl	= nfs3_get_acl,

@@ -1059,6 +1060,7 @@ static const struct inode_operations nfs3_file_inode_operations = {
 	.permission	= nfs_permission,
 	.getattr	= nfs_getattr,
 	.setattr	= nfs_setattr,
+	.fileattr_get	= nfs_fileattr_get,
 #ifdef CONFIG_NFS_V3_ACL
 	.listxattr	= nfs3_listxattr,
 	.get_inode_acl	= nfs3_get_acl,

index e17d72908412..e745e78faab0 100644
@@ -2276,8 +2276,11 @@ static int decode_pathconf3resok(struct xdr_stream *xdr,
 	if (unlikely(!p))
 		return -EIO;
 	result->max_link = be32_to_cpup(p++);
-	result->max_namelen = be32_to_cpup(p);
-	/* ignore remaining fields */
+	result->max_namelen = be32_to_cpup(p++);
+	p++;	/* ignore no_trunc */
+	p++;	/* ignore chown_restricted */
+	result->case_insensitive = be32_to_cpup(p++) != 0;
+	result->case_preserving = be32_to_cpup(p) != 0;
 	return 0;
 }
 

index ec1ce593dea2..e119c6ff61f0 100644
@@ -11041,6 +11041,7 @@ static const struct inode_operations nfs4_dir_inode_operations = {
 	.getattr	= nfs_getattr,
 	.setattr	= nfs_setattr,
 	.listxattr	= nfs4_listxattr,
+	.fileattr_get	= nfs_fileattr_get,
 };
 
 static const struct inode_operations nfs4_file_inode_operations = {

@@ -11048,6 +11049,7 @@ static const struct inode_operations nfs4_file_inode_operations = {
 	.getattr	= nfs_getattr,
 	.setattr	= nfs_setattr,
 	.listxattr	= nfs4_listxattr,
+	.fileattr_get	= nfs_fileattr_get,
 };
 
 static struct nfs_server *nfs4_clone_server(struct nfs_server *source,

index 39df80e4ae6f..48f02a80b800 100644
@@ -597,6 +597,7 @@ nfs_proc_pathconf(struct nfs_server *server, struct nfs_fh *fhandle,
 {
 	info->max_link = 0;
 	info->max_namelen = NFS2_MAXNAMLEN;
+	info->case_preserving = true;
 	return 0;
 }
 

@@ -718,12 +719,14 @@ static const struct inode_operations nfs_dir_inode_operations = {
 	.permission	= nfs_permission,
 	.getattr	= nfs_getattr,
 	.setattr	= nfs_setattr,
+	.fileattr_get	= nfs_fileattr_get,
 };
 
 static const struct inode_operations nfs_file_inode_operations = {
 	.permission	= nfs_permission,
 	.getattr	= nfs_getattr,
 	.setattr	= nfs_setattr,
+	.fileattr_get	= nfs_fileattr_get,
 };
 
 const struct nfs_rpc_ops nfs_v2_clientops = {

index 58146e935402..74a072896f8d 100644
@@ -22,6 +22,8 @@
 #include <linux/mm.h>
 #include <linux/string.h>
 
+#include "internal.h"
+
 /* Symlink caching in the page cache is even more simplistic
  * and straight-forward than readdir caching.
  */

@@ -74,4 +76,5 @@ const struct inode_operations nfs_symlink_inode_operations = {
 	.get_link	= nfs_get_link,
 	.getattr	= nfs_getattr,
 	.setattr	= nfs_setattr,
+	.fileattr_get	= nfs_fileattr_get,
 };

index 79fe2dfb470f..5f061a9db2c2 100644
@@ -182,6 +182,8 @@ struct nfs_pathconf {
 	struct nfs_fattr	*fattr; /* Post-op attributes */
 	__u32			max_link; /* max # of hard links */
 	__u32			max_namelen; /* max name length */
+	bool			case_insensitive;
+	bool			case_preserving;
 };
 
 struct nfs4_change_info {

index d7047ca6b98d..e73e6d21d36b 100644
@@ -3439,6 +3439,14 @@ int f2fs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
 	if (f2fs_sb_has_project_quota(F2FS_I_SB(inode)))
 		fa->fsx_projid = from_kprojid(&init_user_ns, fi->i_projid);
 
+	/*
+	 * f2fs always preserves case. If this inode is a casefolded
+	 * directory, report case-insensitive; otherwise report
+	 * case-sensitive (standard POSIX behavior).
+	 */
+	fa->case_insensitive = IS_CASEFOLDED(inode);
+	fa->case_preserving = true;
+
 	return 0;
 }
 

index 42bedc4ec7af..c5bd3271aa96 100644
@@ -477,4 +477,5 @@ const struct inode_operations vboxsf_dir_iops = {
 	.symlink = vboxsf_dir_symlink,
 	.getattr = vboxsf_getattr,
 	.setattr = vboxsf_setattr,
+	.fileattr_get = vboxsf_fileattr_get,
 };

index 4bebd947314a..06308e38a70d 100644
@@ -223,7 +223,8 @@ const struct file_operations vboxsf_reg_fops = {
 
 const struct inode_operations vboxsf_reg_iops = {
 	.getattr = vboxsf_getattr,
-	.setattr = vboxsf_setattr
+	.setattr = vboxsf_setattr,
+	.fileattr_get = vboxsf_fileattr_get,
 };
 
 static int vboxsf_read_folio(struct file *file, struct folio *folio)

@@ -390,5 +391,6 @@ static const char *vboxsf_get_link(struct dentry *dentry, struct inode *inode,
 }
 
 const struct inode_operations vboxsf_lnk_iops = {
-	.get_link = vboxsf_get_link
+	.get_link = vboxsf_get_link,
+	.fileattr_get = vboxsf_fileattr_get,
 };

index 241647b060ee..fcabeca2a339 100644
@@ -185,6 +185,10 @@ static int vboxsf_fill_super(struct super_block *sb, struct fs_context *fc)
 	if (err)
 		goto fail_unmap;
 
+	err = vboxsf_query_case_sensitive(sbi);
+	if (err)
+		goto fail_unmap;
+
 	sb->s_magic = VBOXSF_SUPER_MAGIC;
 	sb->s_blocksize = 1024;
 	sb->s_maxbytes = MAX_LFS_FILESIZE;

index 9515bbf0b54c..0908fc071577 100644
@@ -11,6 +11,7 @@
 #include <linux/sizes.h>
 #include <linux/pagemap.h>
 #include <linux/vfs.h>
+#include <linux/fileattr.h>
 #include "vfsmod.h"
 
 struct inode *vboxsf_new_inode(struct super_block *sb)

@@ -567,3 +568,33 @@ int vboxsf_dir_read_all(struct vboxsf_sbi *sbi, struct vboxsf_dir_info *sf_d,
 
 	return err;
 }
+
+int vboxsf_query_case_sensitive(struct vboxsf_sbi *sbi)
+{
+	struct shfl_volinfo volinfo;
+	u32 buf_len;
+	int err;
+
+	buf_len = sizeof(volinfo);
+	err = vboxsf_fsinfo(sbi->root, 0, SHFL_INFO_GET | SHFL_INFO_VOLUME,
+			    &buf_len, &volinfo);
+	if (err)
+		return err;
+
+	sbi->case_insensitive = !volinfo.properties.case_sensitive;
+	return 0;
+}
+
+int vboxsf_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	struct vboxsf_sbi *sbi = VBOXSF_SBI(dentry->d_sb);
+
+	fa->case_insensitive = sbi->case_insensitive;
+	/*
+	 * VirtualBox shared folders always preserve filename case
+	 * exactly as provided by the guest. The host interface does
+	 * not expose a case_preserving property.
+	 */
+	fa->case_preserving = true;
+	return 0;
+}

index 05973eb89d52..b61afd0ce842 100644
@@ -47,6 +47,7 @@ struct vboxsf_sbi {
 	u32 next_generation;
 	u32 root;
 	int bdi_id;
+	bool case_insensitive;
 };
 
 /* per-inode information */

@@ -111,6 +112,11 @@ void vboxsf_dir_info_free(struct vboxsf_dir_info *p);
 int vboxsf_dir_read_all(struct vboxsf_sbi *sbi, struct vboxsf_dir_info *sf_d,
 			u64 handle);
 
+int vboxsf_query_case_sensitive(struct vboxsf_sbi *sbi);
+
+struct file_kattr;
+int vboxsf_fileattr_get(struct dentry *dentry, struct file_kattr *fa);
+
 /* from vboxsf_wrappers.c */
 int vboxsf_connect(void);
 void vboxsf_disconnect(void);

index 09df40b612fb..717cdf726e83 100644
@@ -12,6 +12,7 @@
  *  isofs directory handling functions
  */
 #include <linux/gfp.h>
+#include <linux/fileattr.h>
 #include "isofs.h"
 
 int isofs_name_translate(struct iso_directory_record *de, char *new, struct inode *inode)

@@ -266,6 +267,15 @@ static int isofs_readdir(struct file *file, struct dir_context *ctx)
 	return result;
 }
 
+static int isofs_fileattr_get(struct dentry *dentry, struct file_kattr *fa)
+{
+	struct isofs_sb_info *sbi = ISOFS_SB(dentry->d_sb);
+
+	fa->case_insensitive = sbi->s_check == 'r';
+	fa->case_preserving = true;
+	return 0;
+}
+
 const struct file_operations isofs_dir_operations =
 {
 	.llseek = generic_file_llseek,

@@ -279,6 +289,7 @@ const struct file_operations isofs_dir_operations =
 const struct inode_operations isofs_dir_inode_operations =
 {
 	.lookup = isofs_lookup,
+	.fileattr_get = isofs_fileattr_get,
 };
 
 

index 42adc5461db0..9be0aca01de0 100644
@@ -717,17 +717,19 @@ nfsd3_proc_pathconf(struct svc_rqst *rqstp)
 
 	if (resp->status == nfs_ok) {
 		struct super_block *sb = argp->fh.fh_dentry->d_sb;
+		bool case_insensitive, case_preserving;
 
-		/* Note that we don't care for remote fs's here */
-		switch (sb->s_magic) {
-		case EXT2_SUPER_MAGIC:
+		if (sb->s_magic == EXT2_SUPER_MAGIC) {
 			resp->p_link_max = EXT2_LINK_MAX;
 			resp->p_name_max = EXT2_NAME_LEN;
-			break;
-		case MSDOS_SUPER_MAGIC:
-			resp->p_case_insensitive = 1;
-			resp->p_case_preserving  = 0;
-			break;
+		}
+
+		resp->status = nfsd_get_case_info(&argp->fh,
+						  &case_insensitive,
+						  &case_preserving);
+		if (resp->status == nfs_ok) {
+			resp->p_case_insensitive = case_insensitive;
+			resp->p_case_preserving = case_preserving;
 		}
 	}
 

index 168d3ccc8155..f65985813fbf 100644
@@ -32,6 +32,7 @@
 #include <linux/writeback.h>
 #include <linux/security.h>
 #include <linux/sunrpc/xdr.h>
+#include <linux/fileattr.h>
 
 #include "xdr3.h"
 

@@ -2871,3 +2872,27 @@ nfsd_permission(struct svc_cred *cred, struct svc_export *exp,
 
 	return err? nfserrno(err) : 0;
 }
+
+/**
+ * nfsd_get_case_info - get case sensitivity info for a file handle
+ * @fhp: file handle that has already been verified
+ * @case_insensitive: output, true if the filesystem is case-insensitive
+ * @case_preserving: output, true if the filesystem preserves case
+ *
+ * Returns nfs_ok on success, or an nfserr on failure.
+ */
+__be32
+nfsd_get_case_info(struct svc_fh *fhp, bool *case_insensitive,
+		   bool *case_preserving)
+{
+	struct file_kattr fa = {};
+	int err;
+
+	err = vfs_fileattr_get(fhp->fh_dentry, &fa);
+	if (err && err != -ENOIOCTLCMD)
+		return nfserrno(err);
+
+	*case_insensitive = fa.case_insensitive;
+	*case_preserving = fa.case_preserving;
+	return nfs_ok;
+}

index e192dca4a679..1ff62eecec09 100644
@@ -155,6 +155,8 @@ __be32		nfsd_readdir(struct svc_rqst *, struct svc_fh *,
 			     loff_t *, struct readdir_cd *, nfsd_filldir_t);
 __be32		nfsd_statfs(struct svc_rqst *, struct svc_fh *,
 				struct kstatfs *, int access);
+__be32		nfsd_get_case_info(struct svc_fh *fhp, bool *case_insensitive,
+				   bool *case_preserving);
 
 __be32		nfsd_permission(struct svc_cred *cred, struct svc_export *exp,
 				struct dentry *dentry, int acc);

index 51ef97c25456..167bede81273 100644
@@ -2933,6 +2933,8 @@ struct nfsd4_fattr_args {
 	u32			rdattr_err;
 	bool			contextsupport;
 	bool			ignore_crossmnt;
+	bool			case_insensitive;
+	bool			case_preserving;
 };
 
 typedef __be32(*nfsd4_enc_attr)(struct xdr_stream *xdr,

@@ -3131,6 +3133,18 @@ static __be32 nfsd4_encode_fattr4_acl(struct xdr_stream *xdr,
 	return nfs_ok;
 }
 
+static __be32 nfsd4_encode_fattr4_case_insensitive(struct xdr_stream *xdr,
+					const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_bool(xdr, args->case_insensitive);
+}
+
+static __be32 nfsd4_encode_fattr4_case_preserving(struct xdr_stream *xdr,
+					const struct nfsd4_fattr_args *args)
+{
+	return nfsd4_encode_bool(xdr, args->case_preserving);
+}
+
 static __be32 nfsd4_encode_fattr4_filehandle(struct xdr_stream *xdr,
 					     const struct nfsd4_fattr_args *args)
 {

@@ -3487,8 +3501,8 @@ static const nfsd4_enc_attr nfsd4_enc_fattr4_encode_ops[] = {
 	[FATTR4_ACLSUPPORT]		= nfsd4_encode_fattr4_aclsupport,
 	[FATTR4_ARCHIVE]		= nfsd4_encode_fattr4__noop,
 	[FATTR4_CANSETTIME]		= nfsd4_encode_fattr4__true,
-	[FATTR4_CASE_INSENSITIVE]	= nfsd4_encode_fattr4__false,
-	[FATTR4_CASE_PRESERVING]	= nfsd4_encode_fattr4__true,
+	[FATTR4_CASE_INSENSITIVE]	= nfsd4_encode_fattr4_case_insensitive,
+	[FATTR4_CASE_PRESERVING]	= nfsd4_encode_fattr4_case_preserving,
 	[FATTR4_CHOWN_RESTRICTED]	= nfsd4_encode_fattr4__true,
 	[FATTR4_FILEHANDLE]		= nfsd4_encode_fattr4_filehandle,
 	[FATTR4_FILEID]			= nfsd4_encode_fattr4_fileid,

@@ -3674,8 +3688,9 @@ nfsd4_encode_fattr4(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 		if (err)
 			goto out_nfserr;
 	}
-	if ((attrmask[0] & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) &&
-	    !fhp) {
+	if ((attrmask[0] & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID |
+			    FATTR4_WORD0_CASE_INSENSITIVE |
+			    FATTR4_WORD0_CASE_PRESERVING)) && !fhp) {
 		tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
 		status = nfserr_jukebox;
 		if (!tempfh)

@@ -3687,6 +3702,13 @@ nfsd4_encode_fattr4(struct svc_rqst *rqstp, struct xdr_stream *xdr,
 		args.fhp = tempfh;
 	} else
 		args.fhp = fhp;
+	if (attrmask[0] & (FATTR4_WORD0_CASE_INSENSITIVE |
+			   FATTR4_WORD0_CASE_PRESERVING)) {
+		status = nfsd_get_case_info(args.fhp, &args.case_insensitive,
+					    &args.case_preserving);
+		if (status != nfs_ok)
+			goto out;
+	}
 
 	if (attrmask[0] & FATTR4_WORD0_ACL) {
 		err = nfsd4_get_nfs4_acl(rqstp, dentry, &args.acl);

index 2fcd0d4d1fb0..2db189fef4da 100644
@@ -13,6 +13,7 @@
 #include <linux/falloc.h>
 #include <linux/mount.h>
 #include <linux/filelock.h>
+#include <linux/fileattr.h>
 
 #include "glob.h"
 #include "smbfsctl.h"

@@ -5486,16 +5487,33 @@ static int smb2_get_info_filesystem(struct ksmbd_work *work,
 	case FS_ATTRIBUTE_INFORMATION:
 	{
 		FILE_SYSTEM_ATTRIBUTE_INFO *info;
+		struct file_kattr fa = {};
 		size_t sz;
+		u32 attrs;
+		int err;
 
 		info = (FILE_SYSTEM_ATTRIBUTE_INFO *)rsp->Buffer;
-		info->Attributes = cpu_to_le32(FILE_SUPPORTS_OBJECT_IDS |
-					       FILE_PERSISTENT_ACLS |
-					       FILE_UNICODE_ON_DISK |
-					       FILE_CASE_PRESERVED_NAMES |
-					       FILE_CASE_SENSITIVE_SEARCH |
-					       FILE_SUPPORTS_BLOCK_REFCOUNTING);
+		attrs = FILE_SUPPORTS_OBJECT_IDS |
+			FILE_PERSISTENT_ACLS |
+			FILE_UNICODE_ON_DISK |
+			FILE_SUPPORTS_BLOCK_REFCOUNTING;
 
+		err = vfs_fileattr_get(path.dentry, &fa);
+		if (err && err != -ENOIOCTLCMD) {
+			path_put(&path);
+			return err;
+		}
+		if (err == -ENOIOCTLCMD) {
+			/* Default POSIX: case-sensitive and case-preserving */
+			fa.case_insensitive = false;
+			fa.case_preserving = true;
+		}
+		if (!fa.case_insensitive)
+			attrs |= FILE_CASE_SENSITIVE_SEARCH;
+		if (fa.case_preserving)
+			attrs |= FILE_CASE_PRESERVED_NAMES;
+
+		info->Attributes = cpu_to_le32(attrs);
 		info->Attributes |= cpu_to_le32(server_conf.share_fake_fscaps);
 
 		if (test_share_config_flag(work->tcon->share_conf,