Btrfs: Add support for online device removal

[safe/jmp/linux-2.6] / fs / btrfs / struct-funcs.c

diff --git a/fs/btrfs/struct-funcs.c b/fs/btrfs/struct-funcs.c
index cf68fcf..ad03a32 100644 (file)
--- a/fs/btrfs/struct-funcs.c
+++ b/fs/btrfs/struct-funcs.c
@@ -21,16 +21,15 @@
 u##bits btrfs_##name(struct extent_buffer *eb,                         \
                                   type *s)                             \
 {                                                                      \
-       unsigned long offset = (unsigned long)s +                       \
-                               offsetof(type, member);                 \
-       __le##bits *tmp;                                                \
+       unsigned long part_offset = (unsigned long)s;                   \
+       unsigned long offset = part_offset + offsetof(type, member);    \
+       type *p;                                                        \
        /* ugly, but we want the fast path here */                      \
        if (eb->map_token && offset >= eb->map_start &&                 \
            offset + sizeof(((type *)0)->member) <= eb->map_start +     \
            eb->map_len) {                                              \
-               tmp = (__le##bits *)(eb->kaddr + offset -               \
-                                    eb->map_start);                    \
-               return le##bits##_to_cpu(*tmp);                         \
+               p = (type *)(eb->kaddr + part_offset - eb->map_start);  \
+               return le##bits##_to_cpu(p->member);                    \
        }                                                               \
        {                                                               \
                int err;                                                \
@@ -48,8 +47,8 @@ u##bits btrfs_##name(struct extent_buffer *eb,                                \
                        read_eb_member(eb, s, type, member, &res);      \
                        return le##bits##_to_cpu(res);                  \
                }                                                       \
-               tmp = (__le##bits *)(kaddr + offset - map_start);       \
-               res = le##bits##_to_cpu(*tmp);                          \
+               p = (type *)(kaddr + part_offset - map_start);          \
+               res = le##bits##_to_cpu(p->member);                     \
                if (unmap_on_exit)                                      \
                        unmap_extent_buffer(eb, map_token, KM_USER1);   \
                return res;                                             \
@@ -58,16 +57,15 @@ u##bits btrfs_##name(struct extent_buffer *eb,                              \
 void btrfs_set_##name(struct extent_buffer *eb,                                \
                                    type *s, u##bits val)               \
 {                                                                      \
-       unsigned long offset = (unsigned long)s +                       \
-                               offsetof(type, member);                 \
-       __le##bits *tmp;                                                \
+       unsigned long part_offset = (unsigned long)s;                   \
+       unsigned long offset = part_offset + offsetof(type, member);    \
+       type *p;                                                        \
        /* ugly, but we want the fast path here */                      \
        if (eb->map_token && offset >= eb->map_start &&                 \
            offset + sizeof(((type *)0)->member) <= eb->map_start +     \
            eb->map_len) {                                              \
-               tmp = (__le##bits *)(eb->kaddr + offset -               \
-                                    eb->map_start);                    \
-               *tmp = cpu_to_le##bits(val);                            \
+               p = (type *)(eb->kaddr + part_offset - eb->map_start);  \
+               p->member = cpu_to_le##bits(val);                       \
                return;                                                 \
        }                                                               \
        {                                                               \
@@ -86,8 +84,8 @@ void btrfs_set_##name(struct extent_buffer *eb,                               \
                        write_eb_member(eb, s, type, member, &val);     \
                        return;                                         \
                }                                                       \
-               tmp = (__le##bits *)(kaddr + offset - map_start);       \
-               *tmp = cpu_to_le##bits(val);                            \
+               p = (type *)(kaddr + part_offset - map_start);          \
+               p->member = cpu_to_le##bits(val);                       \
                if (unmap_on_exit)                                      \
                        unmap_extent_buffer(eb, map_token, KM_USER1);   \
        }                                                               \
@@ -95,3 +93,19 @@ void btrfs_set_##name(struct extent_buffer *eb,                              \
 
 #include "ctree.h"
 
+void btrfs_node_key(struct extent_buffer *eb,
+                   struct btrfs_disk_key *disk_key, int nr)
+{
+       unsigned long ptr = btrfs_node_key_ptr_offset(nr);
+       if (eb->map_token && ptr >= eb->map_start &&
+           ptr + sizeof(*disk_key) <= eb->map_start + eb->map_len) {
+               memcpy(disk_key, eb->kaddr + ptr - eb->map_start,
+                       sizeof(*disk_key));
+               return;
+       } else if (eb->map_token) {
+               unmap_extent_buffer(eb, eb->map_token, KM_USER1);
+               eb->map_token = NULL;
+       }
+       read_eb_member(eb, (struct btrfs_key_ptr *)ptr,
+                      struct btrfs_key_ptr, key, disk_key);
+}