xfs: add EOFBLOCKS inode tagging/untagging
Add the XFS_ICI_EOFBLOCKS_TAG inode tag to identify inodes with
speculatively preallocated blocks beyond EOF. An inode is tagged
when speculative preallocation occurs and untagged either via
truncate down or when post-EOF blocks are freed via release or
reclaim.
The tag management is intentionally not aggressive to prefer
simplicity over the complexity of handling all the corner cases
under which post-EOF blocks could be freed (i.e., forward
truncation, fallocate, write error conditions, etc.). This means
that a tagged inode may or may not have post-EOF blocks after a
period of time. The tag is eventually cleared when the inode is
released or reclaimed.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 4e00cf0..81f5c49 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -38,6 +38,7 @@
#include "xfs_vnodeops.h"
#include "xfs_inode_item.h"
#include "xfs_trace.h"
+#include "xfs_icache.h"
#include <linux/capability.h>
#include <linux/xattr.h>
@@ -854,6 +855,9 @@
* and do not wait the usual (long) time for writeout.
*/
xfs_iflags_set(ip, XFS_ITRUNCATED);
+
+ /* A truncate down always removes post-EOF blocks. */
+ xfs_inode_clear_eofblocks_tag(ip);
}
if (mask & ATTR_CTIME) {