xfs: Remote attr validation fixes and optimisations

- optimise the calcuation for the number of blocks in a remote
  xattr.
- check attribute length against MAX_XATTR_SIZE, not MAXPATHLEN
- whitespace fixes

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 5 insertions, 14 deletions

diff --git a/fs/xfs/xfs_attr_remote.c b/fs/xfs/xfs_attr_remote.c
index 53da46b46c2f..dee84466dcc9 100644
--- a/fs/xfs/xfs_attr_remote.c
+++ b/fs/xfs/xfs_attr_remote.c
@@ -52,15 +52,9 @@ xfs_attr3_rmt_blocks(
         struct xfs_mount *mp,
         int             attrlen)
 {
-        int             fsblocks = 0;
-        int             len = attrlen;
-
-        do {
-                fsblocks++;
-                len -= XFS_ATTR3_RMT_BUF_SPACE(mp, mp->m_sb.sb_blocksize);
-        } while (len > 0);
-
-        return fsblocks;
+        int             buflen = XFS_ATTR3_RMT_BUF_SPACE(mp,
+                                                         mp->m_sb.sb_blocksize);
+        return (attrlen + buflen - 1) / buflen;
 }
 
 static bool
@@ -79,7 +73,7 @@ xfs_attr3_rmt_verify(
         if (bp->b_bn != be64_to_cpu(rmt->rm_blkno))
                 return false;
         if (be32_to_cpu(rmt->rm_offset) +
-                                be32_to_cpu(rmt->rm_bytes) >= MAXPATHLEN)
+                                be32_to_cpu(rmt->rm_bytes) >= XATTR_SIZE_MAX)
                 return false;
         if (rmt->rm_owner == 0)
                 return false;
@@ -183,7 +177,6 @@ xfs_attr3_rmt_hdr_ok(
 
         /* ok */
         return true;
-
 }
 
 /*
@@ -367,7 +360,6 @@ xfs_attr_rmtval_set(
                  * spill for another block every 9 headers we require in this
                  * loop.
                  */
-
                 if (crcs && blkcnt == 0) {
                         int total_len;
 
@@ -422,9 +414,8 @@ xfs_attr_rmtval_set(
 
                 byte_cnt = BBTOB(bp->b_length);
                 byte_cnt = XFS_ATTR3_RMT_BUF_SPACE(mp, byte_cnt);
-                if (valuelen < byte_cnt) {
+                if (valuelen < byte_cnt)
                         byte_cnt = valuelen;
-                }
 
                 buf = bp->b_addr;
                 buf += xfs_attr3_rmt_hdr_set(mp, dp->i_ino, offset,