Make "extent size" only mandatory for persistent snapshots.

diff --git a/kernel/common/dm-snapshot.c b/kernel/common/dm-snapshot.c
index 8675f2084dd69b9864bf20d03699329f093d956f..6019986fb096393014b0fafa40744a0a9fb830e5 100644 (file)
--- a/kernel/common/dm-snapshot.c
+++ b/kernel/common/dm-snapshot.c
@@ -771,7 +771,7 @@ static int snapshot_ctr(struct dm_table *t, offset_t b, offset_t l,
 {
        struct snapshot_c *lc;
        unsigned long chunk_size;
-       unsigned long extent_size;
+       unsigned long extent_size = 0L;
        int r = -EINVAL;
        char *persistent;
        char *origin_path;
@@ -779,7 +779,7 @@ static int snapshot_ctr(struct dm_table *t, offset_t b, offset_t l,
        char *value;
        int blocksize;
 
-       if (argc < 5) {
+       if (argc < 4) {
                *context = "dm-snapshot: Not enough arguments";
                return -EINVAL;
        }
@@ -799,10 +799,17 @@ static int snapshot_ctr(struct dm_table *t, offset_t b, offset_t l,
                goto bad;
        }
 
-       extent_size = simple_strtoul(argv[4], &value, 10);
-       if (extent_size == 0 || value == NULL) {
-               *context = "Invalid extent size";
-               goto bad;
+       /* Get the extent size for persistent snapshots */
+       if ((*persistent & 0x5f) == 'P') {
+               *context = "No extent size specified";
+               if (argc < 5)
+                       goto bad;
+
+               extent_size = simple_strtoul(argv[4], &value, 10);
+               if (extent_size == 0 || value == NULL) {
+                       *context = "Invalid extent size";
+                       goto bad;
+               }
        }
 
        *context = "Cannot allocate snapshot context private structure";
@@ -878,16 +885,14 @@ static int snapshot_ctr(struct dm_table *t, offset_t b, offset_t l,
           to check the LV header */
        if ((*persistent & 0x5f) == 'P') {
                lc->persistent = 1;
-       }
-       else {
-               lc->persistent = 0;
-       }
 
-       /* For a persistent snapshot allocate the COW iobuf and set associated variables */
-       if (lc->persistent) {
+               /* Allocate the COW iobuf and set associated variables */
                if (setup_persistent_snapshot(lc, blocksize, context))
                        goto bad_free1;
        }
+       else {
+               lc->persistent = 0;
+       }
 
        /* Flush IO to the origin device */
        /* TODO: VFS lock sync too */