[PATCH v11 15/25] xfs: Add helpers xfs_attr_is_shortform and xfs_attr_set_shortform

Allison Collins
2020-07-21T00:18:19Z

In this patch, we hoist code from xfs_attr_set_args into two new helpers
xfs_attr_is_shortform and xfs_attr_set_shortform. These two will help
to simplify xfs_attr_set_args when we get into delayed attrs later.

Signed-off-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_attr.c | 107 +++++++++++++++++++++++++++++++----------------
1 file changed, 72 insertions(+), 35 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index f1becca..b828f3b 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -204,6 +204,66 @@ xfs_attr_try_sf_addname(
}

/*
+ * Check to see if the attr should be upgraded from non-existent or shortform to
+ * single-leaf-block attribute list.
+ */
+static inline bool
+xfs_attr_is_shortform(
+ struct xfs_inode *ip)
+{
+ return ip->i_afp->if_format == XFS_DINODE_FMT_LOCAL ||
+ (ip->i_afp->if_format == XFS_DINODE_FMT_EXTENTS &&
+ ip->i_afp->if_nextents == 0);
+}
+
+/*
+ * Attempts to set an attr in shortform, or converts short form to leaf form if
+ * there is not enough room. If the attr is set, the transaction is committed
+ * and set to NULL.
+ */
+STATIC int
+xfs_attr_set_shortform(
+ struct xfs_da_args *args,
+ struct xfs_buf **leaf_bp)
+{
+ struct xfs_inode *dp = args->dp;
+ int error, error2 = 0;
+
+ /*
+ * Try to add the attr to the attribute list in the inode.
+ */
+ error = xfs_attr_try_sf_addname(dp, args);
+ if (error != -ENOSPC) {
+ error2 = xfs_trans_commit(args->trans);
+ args->trans = NULL;
+ return error ? error : error2;
+ }
+ /*
+ * It won't fit in the shortform, transform to a leaf block. GROT:
+ * another possible req'mt for a double-split btree op.
+ */
+ error = xfs_attr_shortform_to_leaf(args, leaf_bp);
+ if (error)
+ return error;
+
+ /*
+ * Prevent the leaf buffer from being unlocked so that a concurrent AIL
+ * push cannot grab the half-baked leaf buffer and run into problems
+ * with the write verifier. Once we're done rolling the transaction we
+ * can release the hold and add the attr to the leaf.
+ */
+ xfs_trans_bhold(args->trans, *leaf_bp);
+ error = xfs_defer_finish(&args->trans);
+ xfs_trans_bhold_release(args->trans, *leaf_bp);
+ if (error) {
+ xfs_trans_brelse(args->trans, *leaf_bp);
+ return error;
+ }
+
+ return 0;
+}
+
+/*
* Set the attribute specified in @args.
*/
int
@@ -212,48 +272,25 @@ xfs_attr_set_args(
{
struct xfs_inode *dp = args->dp;
struct xfs_buf *leaf_bp = NULL;
- int error, error2 = 0;
+ int error = 0;

/*
- * If the attribute list is non-existent or a shortform list,
- * upgrade it to a single-leaf-block attribute list.
+ * If the attribute list is already in leaf format, jump straight to
+ * leaf handling. Otherwise, try to add the attribute to the shortform
+ * list; if there's no room then convert the list to leaf format and try
+ * again.
*/
- if (dp->i_afp->if_format == XFS_DINODE_FMT_LOCAL ||
- (dp->i_afp->if_format == XFS_DINODE_FMT_EXTENTS &&
- dp->i_afp->if_nextents == 0)) {
+ if (xfs_attr_is_shortform(dp)) {

/*
- * Try to add the attr to the attribute list in the inode.
+ * If the attr was successfully set in shortform, the
+ * transaction is committed and set to NULL. Otherwise, is it
+ * converted from shortform to leaf, and the transaction is
+ * retained.
*/
- error = xfs_attr_try_sf_addname(dp, args);
- if (error != -ENOSPC) {
- error2 = xfs_trans_commit(args->trans);
- args->trans = NULL;
- return error ? error : error2;
- }
-
- /*
- * It won't fit in the shortform, transform to a leaf block.
- * GROT: another possible req'mt for a double-split btree op.
- */
- error = xfs_attr_shortform_to_leaf(args, &leaf_bp);
- if (error)
- return error;
-
- /*
- * Prevent the leaf buffer from being unlocked so that a
- * concurrent AIL push cannot grab the half-baked leaf
- * buffer and run into problems with the write verifier.
- * Once we're done rolling the transaction we can release
- * the hold and add the attr to the leaf.
- */
- xfs_trans_bhold(args->trans, leaf_bp);
- error = xfs_defer_finish(&args->trans);
- xfs_trans_bhold_release(args->trans, leaf_bp);
- if (error) {
- xfs_trans_brelse(args->trans, leaf_bp);
+ error = xfs_attr_set_shortform(args, &leaf_bp);
+ if (error || !args->trans)
return error;
- }
}

if (xfs_bmap_one_block(dp, XFS_ATTR_FORK)) {
--
2.7.4