xfs: add minimum file size filtering to eofblocks scan

Support minimum file size filtering in the eofblocks scan. The
caller must set the XFS_EOF_FLAGS_MINFILESIZE flags bit and minimum
file size value in bytes.
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

fs/xfs/xfs_fs.h

@@ -350,7 +350,8 @@ struct xfs_eofblocks {
 	gid_t		eof_gid;
 	prid_t		eof_prid;
 	__u32		pad32;
-	__u64		pad64[13];
+	__u64		eof_min_file_size;
+	__u64		pad64[12];
 };
 
 /* eof_flags values */
@@ -358,11 +359,13 @@ struct xfs_eofblocks {
 #define XFS_EOF_FLAGS_UID		(1 << 1) /* filter by uid */
 #define XFS_EOF_FLAGS_GID		(1 << 2) /* filter by gid */
 #define XFS_EOF_FLAGS_PRID		(1 << 3) /* filter by project id */
+#define XFS_EOF_FLAGS_MINFILESIZE	(1 << 4) /* filter by min file size */
 #define XFS_EOF_FLAGS_VALID	\
 	(XFS_EOF_FLAGS_SYNC |	\
 	 XFS_EOF_FLAGS_UID |	\
 	 XFS_EOF_FLAGS_GID |	\
-	 XFS_EOF_FLAGS_PRID)
+	 XFS_EOF_FLAGS_PRID |	\
+	 XFS_EOF_FLAGS_MINFILESIZE)
 
 
 /*

fs/xfs/xfs_icache.c

@@ -1215,9 +1215,16 @@ xfs_inode_free_eofblocks(
 	    mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY))
 		return 0;
 
-	if (eofb && !xfs_inode_match_id(ip, eofb))
+	if (eofb) {
+		if (!xfs_inode_match_id(ip, eofb))
 			return 0;
 
+		/* skip the inode if the file size is too small */
+		if (eofb->eof_flags & XFS_EOF_FLAGS_MINFILESIZE &&
+		    XFS_ISIZE(ip) < eofb->eof_min_file_size)
+			return 0;
+	}
+
 	ret = xfs_free_eofblocks(ip->i_mount, ip, true);
 
 	/* don't revisit the inode if we're not waiting */