xfs: introduce XFS_MAX_FILEOFF

commit 20bd9977b25ef48c52279b59b3597b05e78ab5bf upstream.

Introduce a new #define for the maximum supported file block offset.
We'll use this in the next patch to make it more obvious that we're
doing some operation for all possible inode fork mappings after a given
offset.  We can't use ULLONG_MAX here because bunmapi uses that to
detect when it's done.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index c968b60cee15bf14d8d6d590db9e8e83802ce117..28203b626f6a27245a584b45cebed00a39ae2ab9 100644 (file)
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -1540,6 +1540,13 @@ typedef struct xfs_bmdr_block {
 #define BMBT_BLOCKCOUNT_BITLEN 21
 
 #define BMBT_STARTOFF_MASK     ((1ULL << BMBT_STARTOFF_BITLEN) - 1)
+#define BMBT_BLOCKCOUNT_MASK   ((1ULL << BMBT_BLOCKCOUNT_BITLEN) - 1)
+
+/*
+ * bmbt records have a file offset (block) field that is 54 bits wide, so this
+ * is the largest xfs_fileoff_t that we ever expect to see.
+ */
+#define XFS_MAX_FILEOFF                (BMBT_STARTOFF_MASK + BMBT_BLOCKCOUNT_MASK)
 
 typedef struct xfs_bmbt_rec {
        __be64                  l0, l1;

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 904d8285c226962ae7beff6a60b31b70a48a5603..dfbf3f8f1ec86018580838fe3ee3f1c77790aaa1 100644 (file)
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1544,7 +1544,8 @@ xfs_reflink_clear_inode_flag(
         * We didn't find any shared blocks so turn off the reflink flag.
         * First, get rid of any leftover CoW mappings.
         */
-       error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, NULLFILEOFF, true);
+       error = xfs_reflink_cancel_cow_blocks(ip, tpp, 0, XFS_MAX_FILEOFF,
+                       true);
        if (error)
                return error;