xfs: make XBF_MAPPED the default behaviour
Rather than specifying XBF_MAPPED for almost all buffers, introduce
XBF_UNMAPPED for the couple of users that use unmapped buffers.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ben Myers <bpm@sgi.com>
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index b2795ba..172d3cc 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -65,11 +65,11 @@
/*
* 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 @@
* 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 @@
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 @@
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 @@
if (!bp->b_addr)
return -ENOMEM;
bp->b_addr += bp->b_offset;
- bp->b_flags |= XBF_MAPPED;
}
return 0;
@@ -520,7 +520,7 @@
*/
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 @@
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 @@
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 @@
bp->b_io_length = BTOBB(len);
bp->b_length = BTOBB(buflen);
- bp->b_flags |= XBF_MAPPED;
return 0;
}
@@ -790,7 +788,7 @@
}
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 @@
{
struct page *page;
- if (bp->b_flags & XBF_MAPPED)
+ if (bp->b_addr)
return bp->b_addr + offset;
offset += bp->b_offset;