udf: Unify common handling of descriptors

When scanning Volume Descriptor Sequence, several descriptors have
exactly the same handling. Unify it.

Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 7712fa4..3e9925a 100644 (file)
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1593,6 +1593,21 @@ static void udf_load_logicalvolint(struct super_block *sb, struct kernel_extent_
        sbi->s_lvid_bh = NULL;
 }
 
+static struct udf_vds_record *get_volume_descriptor_record(
+               struct udf_vds_record *vds, uint16_t ident)
+{
+       switch (ident) {
+       case TAG_IDENT_PVD: /* ISO 13346 3/10.1 */
+               return &vds[VDS_POS_PRIMARY_VOL_DESC];
+       case TAG_IDENT_IUVD: /* ISO 13346 3/10.4 */
+               return &vds[VDS_POS_IMP_USE_VOL_DESC];
+       case TAG_IDENT_LVD: /* ISO 13346 3/10.6 */
+               return &vds[VDS_POS_LOGICAL_VOL_DESC];
+       case TAG_IDENT_USD: /* ISO 13346 3/10.8 */
+               return &vds[VDS_POS_UNALLOC_SPACE_DESC];
+       }
+       return NULL;
+}
 
 /*
  * Process a main/reserve volume descriptor sequence.
@@ -1635,13 +1650,6 @@ static noinline int udf_process_sequence(
                gd = (struct generic_desc *)bh->b_data;
                vdsn = le32_to_cpu(gd->volDescSeqNum);
                switch (ident) {
-               case TAG_IDENT_PVD: /* ISO 13346 3/10.1 */
-                       curr = &vds[VDS_POS_PRIMARY_VOL_DESC];
-                       if (vdsn >= curr->volDescSeqNum) {
-                               curr->volDescSeqNum = vdsn;
-                               curr->block = block;
-                       }
-                       break;
                case TAG_IDENT_VDP: /* ISO 13346 3/10.3 */
                        if (++indirections > UDF_MAX_TD_NESTING) {
                                udf_err(sb, "too many Volume Descriptor "
@@ -1660,8 +1668,11 @@ static noinline int udf_process_sequence(
                        /* For loop is going to increment 'block' again */
                        block--;
                        break;
+               case TAG_IDENT_PVD: /* ISO 13346 3/10.1 */
                case TAG_IDENT_IUVD: /* ISO 13346 3/10.4 */
-                       curr = &vds[VDS_POS_IMP_USE_VOL_DESC];
+               case TAG_IDENT_LVD: /* ISO 13346 3/10.6 */
+               case TAG_IDENT_USD: /* ISO 13346 3/10.8 */
+                       curr = get_volume_descriptor_record(vds, ident);
                        if (vdsn >= curr->volDescSeqNum) {
                                curr->volDescSeqNum = vdsn;
                                curr->block = block;
@@ -1672,20 +1683,6 @@ static noinline int udf_process_sequence(
                        if (!curr->block)
                                curr->block = block;
                        break;
-               case TAG_IDENT_LVD: /* ISO 13346 3/10.6 */
-                       curr = &vds[VDS_POS_LOGICAL_VOL_DESC];
-                       if (vdsn >= curr->volDescSeqNum) {
-                               curr->volDescSeqNum = vdsn;
-                               curr->block = block;
-                       }
-                       break;
-               case TAG_IDENT_USD: /* ISO 13346 3/10.8 */
-                       curr = &vds[VDS_POS_UNALLOC_SPACE_DESC];
-                       if (vdsn >= curr->volDescSeqNum) {
-                               curr->volDescSeqNum = vdsn;
-                               curr->block = block;
-                       }
-                       break;
                case TAG_IDENT_TD: /* ISO 13346 3/10.9 */
                        vds[VDS_POS_TERMINATING_DESC].block = block;
                        done = true;