xfs: make XBF_MAPPED the default behaviour

[firefly-linux-kernel-4.4.55.git] / fs / xfs / xfs_buf.c

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index b2795bab1a01bbb4187f2bab3a45101586f93a33..172d3cc8f8cb8ad6d588fea95819ecfded627167 100644 (file)
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -65,11 +65,11 @@ xfs_buf_is_vmapped(
        /*
         * Return true if the buffer is vmapped.
         *
-        * The XBF_MAPPED flag is set if the buffer should be mapped, but the
-        * code is clever enough to know it doesn't have to map a single page,
-        * so the check has to be both for XBF_MAPPED and bp->b_page_count > 1.
+        * b_addr is null if the buffer is not mapped, but the code is clever
+        * enough to know it doesn't have to map a single page, so the check has
+        * to be both for b_addr and bp->b_page_count > 1.
         */
-       return (bp->b_flags & XBF_MAPPED) && bp->b_page_count > 1;
+       return bp->b_addr && bp->b_page_count > 1;
 }
 
 static inline int
@@ -181,7 +181,7 @@ xfs_buf_alloc(
         * We don't want certain flags to appear in b_flags unless they are
         * specifically set by later operations on the buffer.
         */
-       flags &= ~(XBF_MAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD);
+       flags &= ~(XBF_UNMAPPED | XBF_TRYLOCK | XBF_ASYNC | XBF_READ_AHEAD);
 
        atomic_set(&bp->b_hold, 1);
        atomic_set(&bp->b_lru_ref, 1);
@@ -329,7 +329,7 @@ xfs_buf_allocate_memory(
                bp->b_pages = bp->b_page_array;
                bp->b_pages[0] = virt_to_page(bp->b_addr);
                bp->b_page_count = 1;
-               bp->b_flags |= XBF_MAPPED | _XBF_KMEM;
+               bp->b_flags |= _XBF_KMEM;
                return 0;
        }
 
@@ -399,8 +399,9 @@ _xfs_buf_map_pages(
        if (bp->b_page_count == 1) {
                /* A single page buffer is always mappable */
                bp->b_addr = page_address(bp->b_pages[0]) + bp->b_offset;
-               bp->b_flags |= XBF_MAPPED;
-       } else if (flags & XBF_MAPPED) {
+       } else if (flags & XBF_UNMAPPED) {
+               bp->b_addr = NULL;
+       } else {
                int retried = 0;
 
                do {
@@ -414,7 +415,6 @@ _xfs_buf_map_pages(
                if (!bp->b_addr)
                        return -ENOMEM;
                bp->b_addr += bp->b_offset;
-               bp->b_flags |= XBF_MAPPED;
        }
 
        return 0;
@@ -520,7 +520,7 @@ found:
         */
        if (bp->b_flags & XBF_STALE) {
                ASSERT((bp->b_flags & _XBF_DELWRI_Q) == 0);
-               bp->b_flags &= XBF_MAPPED | _XBF_KMEM | _XBF_PAGES;
+               bp->b_flags &= _XBF_KMEM | _XBF_PAGES;
        }
 
        trace_xfs_buf_find(bp, flags, _RET_IP_);
@@ -575,7 +575,7 @@ xfs_buf_get(
        bp->b_io_length = bp->b_length;
 
 found:
-       if (!(bp->b_flags & XBF_MAPPED)) {
+       if (!bp->b_addr) {
                error = _xfs_buf_map_pages(bp, flags);
                if (unlikely(error)) {
                        xfs_warn(target->bt_mount,
@@ -707,7 +707,6 @@ xfs_buf_set_empty(
        bp->b_length = numblks;
        bp->b_io_length = numblks;
        bp->b_bn = XFS_BUF_DADDR_NULL;
-       bp->b_flags &= ~XBF_MAPPED;
 }
 
 static inline struct page *
@@ -759,7 +758,6 @@ xfs_buf_associate_memory(
 
        bp->b_io_length = BTOBB(len);
        bp->b_length = BTOBB(buflen);
-       bp->b_flags |= XBF_MAPPED;
 
        return 0;
 }
@@ -790,7 +788,7 @@ xfs_buf_get_uncached(
        }
        bp->b_flags |= _XBF_PAGES;
 
-       error = _xfs_buf_map_pages(bp, XBF_MAPPED);
+       error = _xfs_buf_map_pages(bp, 0);
        if (unlikely(error)) {
                xfs_warn(target->bt_mount,
                        "%s: failed to map pages\n", __func__);
@@ -1287,7 +1285,7 @@ xfs_buf_offset(
 {
        struct page             *page;
 
-       if (bp->b_flags & XBF_MAPPED)
+       if (bp->b_addr)
                return bp->b_addr + offset;
 
        offset += bp->b_offset;