From: Chuck Lever Upper layers such as NFSD need a way to query whether a filesystem handles filenames in a case-sensitive manner. The file_kattr structure now provides case_insensitive and case_preserving fields for this purpose, but CIFS does not yet report its case sensitivity behavior through this interface. Implement cifs_fileattr_get() to report CIFS/SMB case handling behavior. CIFS servers (typically Windows or Samba) are usually case-insensitive but case-preserving, meaning they ignore case during lookups but store filenames exactly as provided. The implementation reports case sensitivity based on the nocase mount option, which reflects whether the client expects the server to perform case-insensitive comparisons. When nocase is set, the mount is reported as case-insensitive. The case_preserving field is always set to true since SMB servers preserve filename case at rest. The callback is registered in all three inode_operations structures (directory, file, and symlink) to ensure consistent reporting across all inode types. Signed-off-by: Chuck Lever --- fs/smb/client/cifsfs.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c index d9664634144d..563eece79b13 100644 --- a/fs/smb/client/cifsfs.c +++ b/fs/smb/client/cifsfs.c @@ -30,6 +30,7 @@ #include #include #include +#include #include #include #include "cifsfs.h" @@ -1193,6 +1194,20 @@ 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 and + * case-preserving (the default). The nocase mount option + * reflects what the client expects from the server. + */ + fa->case_insensitive = tcon->nocase; + return 0; +} + const struct inode_operations cifs_dir_inode_ops = { .create = cifs_create, .atomic_open = cifs_atomic_open, @@ -1210,6 +1225,7 @@ 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 +1236,7 @@ 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 +1271,7 @@ const struct inode_operations cifs_symlink_inode_ops = { .setattr = cifs_setattr, .permission = cifs_permission, .listxattr = cifs_listxattr, + .fileattr_get = cifs_fileattr_get, }; /* -- 2.52.0