LU-13791 mdt: parameter to tune capabilities

[fs/lustre-release.git] / lustre / mdt / mdt_lproc.c

diff --git a/lustre/mdt/mdt_lproc.c b/lustre/mdt/mdt_lproc.c
index 9b13a3b..c6108eb 100644 (file)
--- a/lustre/mdt/mdt_lproc.c
+++ b/lustre/mdt/mdt_lproc.c
@@ -589,6 +589,55 @@ mdt_nosquash_nids_seq_write(struct file *file, const char __user *buffer,
 }
 LPROC_SEQ_FOPS(mdt_nosquash_nids);
 
+static ssize_t enable_cap_mask_show(struct kobject *kobj,
+                                   struct attribute *attr, char *buf)
+{
+       struct obd_device *obd = container_of(kobj, struct obd_device,
+                                             obd_kset.kobj);
+       struct mdt_device *mdt = mdt_dev(obd->obd_lu_dev);
+       u64 cap;
+
+       BUILD_BUG_ON(_KERNEL_CAP_T_SIZE != sizeof(u64));
+
+#ifdef CAP_FOR_EACH_U32 /* kernels before v6.2-13111-gf122a08b197d */
+       cap = ((u64)mdt->mdt_enable_cap_mask.cap[1] << 32) |
+              mdt->mdt_enable_cap_mask.cap[0];
+#else
+       cap = mdt->mdt_enable_cap_mask.val;
+#endif
+       return scnprintf(buf, PAGE_SIZE, "%#0llx\n", cap);
+}
+
+static ssize_t enable_cap_mask_store(struct kobject *kobj,
+                                    struct attribute *attr,
+                                    const char *buffer, size_t count)
+{
+       struct obd_device *obd = container_of(kobj, struct obd_device,
+                                             obd_kset.kobj);
+       struct mdt_device *mdt = mdt_dev(obd->obd_lu_dev);
+       unsigned long long val;
+       int rc;
+
+       rc = kstrtoull(buffer, 0, &val);
+       if (rc)
+               /* should also accept symbolic names via cfs_str2mask() */
+               return rc;
+
+#ifdef CAP_FOR_EACH_U32
+       mdt->mdt_enable_cap_mask.cap[0] = val &
+               (CAP_FS_MASK_B0 | CAP_TO_MASK(CAP_SYS_RESOURCE) |
+                CAP_TO_MASK(CAP_LINUX_IMMUTABLE));
+       mdt->mdt_enable_cap_mask.cap[1] = (val >> 32) & CAP_FS_MASK_B1;
+#else
+       mdt->mdt_enable_cap_mask.val = val &
+               (CAP_FS_MASK | BIT_ULL(CAP_SYS_RESOURCE) |
+                BIT_ULL(CAP_LINUX_IMMUTABLE));
+#endif
+
+       return count;
+}
+LUSTRE_RW_ATTR(enable_cap_mask);
+
 static ssize_t enable_remote_dir_gid_show(struct kobject *kobj,
                                          struct attribute *attr, char *buf)
 {
@@ -1267,6 +1316,7 @@ static struct attribute *mdt_attrs[] = {
        &lustre_attr_identity_upcall.attr,
        &lustre_attr_identity_flush.attr,
        &lustre_attr_evict_tgt_nids.attr,
+       &lustre_attr_enable_cap_mask.attr,
        &lustre_attr_enable_chprojid_gid.attr,
        &lustre_attr_enable_dir_migration.attr,
        &lustre_attr_enable_dir_restripe.attr,