staging/lustre/llite: move root_squash from sysfs to debugfs

commit 4c13990e35b9f053857d4ad83bf0f58e612ec414 upstream.

root_squash control got accidentally moved to sysfs instead of
debugfs, and the write side of it was also broken expecting a
userspace buffer.
It contains both uid and gid values in a single file, so debugfs
is a clear place for it.

Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Fixes: c948390f10ccc "fix inconsistencies of root squash feature"
Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 15 insertions, 12 deletions

diff --git a/drivers/staging/lustre/lustre/llite/lproc_llite.c b/drivers/staging/lustre/lustre/llite/lproc_llite.c
index 23fda9d98bff..13ec24d44b04 100644
--- a/drivers/staging/lustre/lustre/llite/lproc_llite.c
+++ b/drivers/staging/lustre/lustre/llite/lproc_llite.c
@@ -924,27 +924,29 @@ static ssize_t ll_unstable_stats_seq_write(struct file *file,
 }
 LPROC_SEQ_FOPS(ll_unstable_stats);
 
-static ssize_t root_squash_show(struct kobject *kobj, struct attribute *attr,
-                                char *buf)
+static int ll_root_squash_seq_show(struct seq_file *m, void *v)
 {
-        struct ll_sb_info *sbi = container_of(kobj, struct ll_sb_info,
-                                              ll_kobj);
+        struct super_block *sb = m->private;
+        struct ll_sb_info *sbi = ll_s2sbi(sb);
         struct root_squash_info *squash = &sbi->ll_squash;
 
-        return sprintf(buf, "%u:%u\n", squash->rsi_uid, squash->rsi_gid);
+        seq_printf(m, "%u:%u\n", squash->rsi_uid, squash->rsi_gid);
+        return 0;
 }
 
-static ssize_t root_squash_store(struct kobject *kobj, struct attribute *attr,
-                                 const char *buffer, size_t count)
+static ssize_t ll_root_squash_seq_write(struct file *file,
+                                        const char __user *buffer,
+                                        size_t count, loff_t *off)
 {
-        struct ll_sb_info *sbi = container_of(kobj, struct ll_sb_info,
-                                              ll_kobj);
+        struct seq_file *m = file->private_data;
+        struct super_block *sb = m->private;
+        struct ll_sb_info *sbi = ll_s2sbi(sb);
         struct root_squash_info *squash = &sbi->ll_squash;
 
         return lprocfs_wr_root_squash(buffer, count, squash,
-                                      ll_get_fsname(sbi->ll_sb, NULL, 0));
+                                      ll_get_fsname(sb, NULL, 0));
 }
-LUSTRE_RW_ATTR(root_squash);
+LPROC_SEQ_FOPS(ll_root_squash);
 
 static int ll_nosquash_nids_seq_show(struct seq_file *m, void *v)
 {
@@ -997,6 +999,8 @@ static struct lprocfs_vars lprocfs_llite_obd_vars[] = {
         { "statahead_stats",  &ll_statahead_stats_fops, NULL, 0 },
         { "unstable_stats",   &ll_unstable_stats_fops, NULL },
         { "sbi_flags",        &ll_sbi_flags_fops, NULL, 0 },
+        { .name =       "root_squash",
+          .fops =       &ll_root_squash_fops                    },
         { .name =               "nosquash_nids",
           .fops =               &ll_nosquash_nids_fops          },
         { NULL }
@@ -1027,7 +1031,6 @@ static struct attribute *llite_attrs[] = {
         &lustre_attr_max_easize.attr,
         &lustre_attr_default_easize.attr,
         &lustre_attr_xattr_cache.attr,
-        &lustre_attr_root_squash.attr,
         NULL,
 };