[PATCH v4 11/17] xfs: Add xfs_attr3_leaf helper functions

Allison Collins
2019-11-07T01:28:59Z

And new helper functions xfs_attr3_leaf_flag_is_set and
xfs_attr3_leaf_flagsflipped. These routines check to see
if xfs_attr3_leaf_setflag or xfs_attr3_leaf_flipflags have
already been run. We will need this later for delayed
attributes since routines may be recalled several times
when -EAGAIN is returned.

Signed-off-by: Allison Collins <allison.henderson@oracle.com>
---
fs/xfs/libxfs/xfs_attr_leaf.c | 94 +++++++++++++++++++++++++++++++++++++++++++
fs/xfs/libxfs/xfs_attr_leaf.h | 2 +
2 files changed, 96 insertions(+)

diff --git a/fs/xfs/libxfs/xfs_attr_leaf.c b/fs/xfs/libxfs/xfs_attr_leaf.c
index 42c037e..023c616 100644
--- a/fs/xfs/libxfs/xfs_attr_leaf.c
+++ b/fs/xfs/libxfs/xfs_attr_leaf.c
@@ -2809,6 +2809,40 @@ xfs_attr3_leaf_clearflag(
}

/*
+ * Check if the INCOMPLETE flag on an entry in a leaf block is set. This
+ * function can be used to check if xfs_attr3_leaf_setflag has already been
+ * called. The INCOMPLETE flag is used during attr rename operations to mark
+ * entries that are being renamed. Since renames should be atomic, only one of
+ * them should appear as a completed attribute.
+ *
+ * isset is set to true if the flag is set or false otherwise
+ */
+int
+xfs_attr3_leaf_flag_is_set(
+ struct xfs_da_args *args,
+ bool *isset)
+{
+ struct xfs_attr_leafblock *leaf;
+ struct xfs_attr_leaf_entry *entry;
+ struct xfs_buf *bp;
+ struct xfs_inode *dp = args->dp;
+ int error = 0;
+
+ error = xfs_attr3_leaf_read(args->trans, dp, args->blkno,
+ XFS_DABUF_MAP_NOMAPPING, &bp);
+ if (error)
+ return error;
+
+ leaf = bp->b_addr;
+ entry = &xfs_attr3_leaf_entryp(leaf)[args->index];
+
+ *isset = ((entry->flags & XFS_ATTR_INCOMPLETE) != 0);
+ xfs_trans_brelse(args->trans, bp);
+
+ return 0;
+}
+
+/*
* Set the INCOMPLETE flag on an entry in a leaf block.
*/
int
@@ -2972,3 +3006,63 @@ xfs_attr3_leaf_flipflags(

return error;
}
+
+/*
+ * On a leaf entry, check to see if the INCOMPLETE flag is cleared
+ * in args->blkno/index and set in args->blkno2/index2. Note that they could be
+ * in different blocks, or in the same block. This function can be used to
+ * check if xfs_attr3_leaf_flipflags has already been called. The INCOMPLETE
+ * flag is used during attr rename operations to mark entries that are being
+ * renamed. Since renames should be atomic, only one of them should appear as a
+ * completed attribute.
+ *
+ * isflipped is set to true if flags are flipped or false otherwise
+ */
+int
+xfs_attr3_leaf_flagsflipped(
+ struct xfs_da_args *args,
+ bool *isflipped)
+{
+ struct xfs_attr_leafblock *leaf1;
+ struct xfs_attr_leafblock *leaf2;
+ struct xfs_attr_leaf_entry *entry1;
+ struct xfs_attr_leaf_entry *entry2;
+ struct xfs_buf *bp1;
+ struct xfs_buf *bp2;
+ struct xfs_inode *dp = args->dp;
+ int error = 0;
+
+ /*
+ * Read the block containing the "old" attr
+ */
+ error = xfs_attr3_leaf_read(args->trans, dp, args->blkno,
+ XFS_DABUF_MAP_NOMAPPING, &bp1);
+ if (error)
+ return error;
+
+ /*
+ * Read the block containing the "new" attr, if it is different
+ */
+ if (args->blkno2 != args->blkno) {
+ error = xfs_attr3_leaf_read(args->trans, args->dp, args->blkno2,
+ -1, &bp2);
+ if (error)
+ return error;
+ } else {
+ bp2 = bp1;
+ }
+
+ leaf1 = bp1->b_addr;
+ entry1 = &xfs_attr3_leaf_entryp(leaf1)[args->index];
+
+ leaf2 = bp2->b_addr;
+ entry2 = &xfs_attr3_leaf_entryp(leaf2)[args->index2];
+
+ *isflipped = (((entry1->flags & XFS_ATTR_INCOMPLETE) == 0) &&
+ (entry2->flags & XFS_ATTR_INCOMPLETE));
+
+ xfs_trans_brelse(args->trans, bp1);
+ xfs_trans_brelse(args->trans, bp2);
+
+ return 0;
+}
diff --git a/fs/xfs/libxfs/xfs_attr_leaf.h b/fs/xfs/libxfs/xfs_attr_leaf.h
index e108b37..12283cf 100644
--- a/fs/xfs/libxfs/xfs_attr_leaf.h
+++ b/fs/xfs/libxfs/xfs_attr_leaf.h
@@ -57,7 +57,9 @@ int xfs_attr3_leaf_to_shortform(struct xfs_buf *bp,
struct xfs_da_args *args, int forkoff);
int xfs_attr3_leaf_clearflag(struct xfs_da_args *args);
int xfs_attr3_leaf_setflag(struct xfs_da_args *args);
+int xfs_attr3_leaf_flag_is_set(struct xfs_da_args *args, bool *isset);
int xfs_attr3_leaf_flipflags(struct xfs_da_args *args);
+int xfs_attr3_leaf_flagsflipped(struct xfs_da_args *args, bool *isflipped);

/*
* Routines used for growing the Btree.
--
2.7.4