Btrfs: introduce common define for max number of mirrors

Readahead already has a define for the max number of mirrors. Scrub
needs such a define now, the rest of the code will need something
like this soon. Therefore the define was added to ctree.h and removed
from the readahead code.

Signed-off-by: Stefan Behrens <sbehrens@giantdisaster.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index c2e17cd..f7da8a8 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -48,6 +48,8 @@ struct btrfs_ordered_sum;
 
 #define BTRFS_MAGIC "_BHRfS_M"
 
+#define BTRFS_MAX_MIRRORS 2
+
 #define BTRFS_MAX_LEVEL 8
 
 #define BTRFS_COMPAT_EXTENT_TREE_V0

diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index 22db045..dc5d331 100644 (file)
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -54,7 +54,6 @@
  * than the 2 started one after another.
  */
 
-#define MAX_MIRRORS 2
 #define MAX_IN_FLIGHT 6
 
 struct reada_extctl {
@@ -71,7 +70,7 @@ struct reada_extent {
        struct list_head        extctl;
        struct kref             refcnt;
        spinlock_t              lock;
-       struct reada_zone       *zones[MAX_MIRRORS];
+       struct reada_zone       *zones[BTRFS_MAX_MIRRORS];
        int                     nzones;
        struct btrfs_device     *scheduled_for;
 };
@@ -84,7 +83,8 @@ struct reada_zone {
        spinlock_t              lock;
        int                     locked;
        struct btrfs_device     *device;
-       struct btrfs_device     *devs[MAX_MIRRORS]; /* full list, incl self */
+       struct btrfs_device     *devs[BTRFS_MAX_MIRRORS]; /* full list, incl
+                                                          * self */
        int                     ndevs;
        struct kref             refcnt;
 };
@@ -365,9 +365,9 @@ again:
        if (ret || !bbio || length < blocksize)
                goto error;
 
-       if (bbio->num_stripes > MAX_MIRRORS) {
+       if (bbio->num_stripes > BTRFS_MAX_MIRRORS) {
                printk(KERN_ERR "btrfs readahead: more than %d copies not "
-                               "supported", MAX_MIRRORS);
+                               "supported", BTRFS_MAX_MIRRORS);
                goto error;
        }