udf: Protect default inode credentials by rwlock
Superblock carries credentials (uid, gid, etc.) which are used as default
values in __udf_read_inode() when media does not provide these. These
credentials can change during remount so we protect them by a rwlock so that
each inode gets a consistent set of credentials.
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/udf/super.c b/fs/udf/super.c
index e54960c..f06cc67 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -568,12 +568,14 @@
return -EINVAL;
lock_kernel();
+ write_lock(&sbi->s_cred_lock);
sbi->s_flags = uopt.flags;
sbi->s_uid = uopt.uid;
sbi->s_gid = uopt.gid;
sbi->s_umask = uopt.umask;
sbi->s_fmode = uopt.fmode;
sbi->s_dmode = uopt.dmode;
+ write_unlock(&sbi->s_cred_lock);
if (sbi->s_lvid_bh) {
int write_rev = le16_to_cpu(udf_sb_lvidiu(sbi)->minUDFWriteRev);
@@ -1960,6 +1962,7 @@
sbi->s_fmode = uopt.fmode;
sbi->s_dmode = uopt.dmode;
sbi->s_nls_map = uopt.nls_map;
+ rwlock_init(&sbi->s_cred_lock);
if (uopt.session == 0xFFFFFFFF)
sbi->s_session = udf_get_last_session(sb);