Btrfs: make profile_is_valid() check more strict

"0" is a valid value for an on-disk chunk profile, but it is not a valid
extended profile.  (We have a separate bit for single chunks in extended
case)

Also rename it to alloc_profile_is_valid() for clarity.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

1 files changed, 13 insertions, 8 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index aba7832a2285..f057e92df39f 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -2735,22 +2735,27 @@ static inline void free_fs_info(struct btrfs_fs_info *fs_info)
         kfree(fs_info);
 }
 /**
- * profile_is_valid - tests whether a given profile is valid and reduced
+ * alloc_profile_is_valid - see if a given profile is valid and reduced
  * @flags: profile to validate
  * @extended: if true @flags is treated as an extended profile
  */
-static inline int profile_is_valid(u64 flags, int extended)
+static inline int alloc_profile_is_valid(u64 flags, int extended)
 {
-        u64 mask = ~BTRFS_BLOCK_GROUP_PROFILE_MASK;
+        u64 mask = (extended ? BTRFS_EXTENDED_PROFILE_MASK :
+                               BTRFS_BLOCK_GROUP_PROFILE_MASK);
 
         flags &= ~BTRFS_BLOCK_GROUP_TYPE_MASK;
-        if (extended)
-                mask &= ~BTRFS_AVAIL_ALLOC_BIT_SINGLE;
 
-        if (flags & mask)
+        /* 1) check that all other bits are zeroed */
+        if (flags & ~mask)
                 return 0;
-        /* true if zero or exactly one bit set */
-        return (flags & (~flags + 1)) == flags;
+
+        /* 2) see if profile is reduced */
+        if (flags == 0)
+                return !extended; /* "0" is valid for usual profiles */
+
+        /* true if exactly one bit set */
+        return (flags & (flags - 1)) == 0;
 }
 
 /* root-item.c */