[PATCH 08/17] xfs: split remote attr setting out from replace path

Dave Chinner
2022-05-06T09:46:08Z

When we set a new xattr, we have three exit paths:

1. nothing else to do
2. allocate and set the remote xattr value
3. perform the rest of a replace operation

Currently we push both 2 and 3 into the same state, regardless of
whether we just set a remote attribute or not. Once we've set the
remote xattr, we have two exit states:

1. nothing else to do
2. perform the rest of a replace operation

Hence we can split the remote xattr allocation and setting into
their own states and factor it out of xfs_attr_set_iter() to further
clean up the state machine and the implementation of the state
machine.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson<allison.henderson@oracle.com>
---
fs/xfs/libxfs/xfs_attr.c | 113 +++++++++++++++++++++------------------
fs/xfs/libxfs/xfs_attr.h | 14 +++--
fs/xfs/xfs_trace.h | 9 ++--
3 files changed, 77 insertions(+), 59 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index be580da62f08..d2b29f7e103a 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -334,9 +334,11 @@ xfs_attr_leaf_addname(
* or perform more xattr manipulations. Otherwise there is nothing more
* to do and we can return success.
*/
- if (args->rmtblkno ||
- (args->op_flags & XFS_DA_OP_RENAME)) {
- attr->xattri_dela_state = XFS_DAS_FOUND_LBLK;
+ if (args->rmtblkno) {
+ attr->xattri_dela_state = XFS_DAS_LEAF_SET_RMT;
+ error = -EAGAIN;
+ } else if (args->op_flags & XFS_DA_OP_RENAME) {
+ attr->xattri_dela_state = XFS_DAS_LEAF_REPLACE;
error = -EAGAIN;
} else {
attr->xattri_dela_state = XFS_DAS_DONE;
@@ -363,9 +365,11 @@ xfs_attr_node_addname(
if (error)
return error;

- if (args->rmtblkno ||
- (args->op_flags & XFS_DA_OP_RENAME)) {
- attr->xattri_dela_state = XFS_DAS_FOUND_NBLK;
+ if (args->rmtblkno) {
+ attr->xattri_dela_state = XFS_DAS_NODE_SET_RMT;
+ error = -EAGAIN;
+ } else if (args->op_flags & XFS_DA_OP_RENAME) {
+ attr->xattri_dela_state = XFS_DAS_NODE_REPLACE;
error = -EAGAIN;
} else {
attr->xattri_dela_state = XFS_DAS_DONE;
@@ -375,6 +379,40 @@ xfs_attr_node_addname(
return error;
}

+static int
+xfs_attr_rmtval_alloc(
+ struct xfs_attr_item *attr)
+{
+ struct xfs_da_args *args = attr->xattri_da_args;
+ int error = 0;
+
+ /*
+ * If there was an out-of-line value, allocate the blocks we
+ * identified for its storage and copy the value. This is done
+ * after we create the attribute so that we don't overflow the
+ * maximum size of a transaction and/or hit a deadlock.
+ */
+ if (attr->xattri_blkcnt > 0) {
+ error = xfs_attr_rmtval_set_blk(attr);
+ if (error)
+ return error;
+ error = -EAGAIN;
+ goto out;
+ }
+
+ error = xfs_attr_rmtval_set_value(args);
+ if (error)
+ return error;
+
+ /* If this is not a rename, clear the incomplete flag and we're done. */
+ if (!(args->op_flags & XFS_DA_OP_RENAME)) {
+ error = xfs_attr3_leaf_clearflag(args);
+ attr->xattri_dela_state = XFS_DAS_DONE;
+ }
+out:
+ trace_xfs_attr_rmtval_alloc(attr->xattri_dela_state, args->dp);
+ return error;
+}

/*
* Set the attribute specified in @args.
@@ -406,54 +444,26 @@ xfs_attr_set_iter(
case XFS_DAS_NODE_ADD:
return xfs_attr_node_addname(attr);

- case XFS_DAS_FOUND_LBLK:
- case XFS_DAS_FOUND_NBLK:
- /*
- * Find space for remote blocks and fall into the allocation
- * state.
- */
- if (args->rmtblkno > 0) {
- error = xfs_attr_rmtval_find_space(attr);
- if (error)
- return error;
- }
+ case XFS_DAS_LEAF_SET_RMT:
+ case XFS_DAS_NODE_SET_RMT:
+ error = xfs_attr_rmtval_find_space(attr);
+ if (error)
+ return error;
attr->xattri_dela_state++;
fallthrough;
+
case XFS_DAS_LEAF_ALLOC_RMT:
case XFS_DAS_NODE_ALLOC_RMT:
-
- /*
- * If there was an out-of-line value, allocate the blocks we
- * identified for its storage and copy the value. This is done
- * after we create the attribute so that we don't overflow the
- * maximum size of a transaction and/or hit a deadlock.
- */
- if (args->rmtblkno > 0) {
- if (attr->xattri_blkcnt > 0) {
- error = xfs_attr_rmtval_set_blk(attr);
- if (error)
- return error;
- trace_xfs_attr_set_iter_return(
- attr->xattri_dela_state,
- args->dp);
- return -EAGAIN;
- }
-
- error = xfs_attr_rmtval_set_value(args);
- if (error)
- return error;
- }
-
- /*
- * If this is not a rename, clear the incomplete flag and we're
- * done.
- */
- if (!(args->op_flags & XFS_DA_OP_RENAME)) {
- if (args->rmtblkno > 0)
- error = xfs_attr3_leaf_clearflag(args);
+ error = xfs_attr_rmtval_alloc(attr);
+ if (error)
return error;
- }
+ if (attr->xattri_dela_state == XFS_DAS_DONE)
+ break;
+ attr->xattri_dela_state++;
+ fallthrough;

+ case XFS_DAS_LEAF_REPLACE:
+ case XFS_DAS_NODE_REPLACE:
/*
* If this is an atomic rename operation, we must "flip" the
* incomplete flags on the "new" and "old" attribute/value pairs
@@ -471,10 +481,9 @@ xfs_attr_set_iter(
* Commit the flag value change and start the next trans
* in series at FLIP_FLAG.
*/
+ error = -EAGAIN;
attr->xattri_dela_state++;
- trace_xfs_attr_set_iter_return(attr->xattri_dela_state,
- args->dp);
- return -EAGAIN;
+ break;
}

attr->xattri_dela_state++;
@@ -549,6 +558,8 @@ xfs_attr_set_iter(
ASSERT(0);
break;
}
+
+ trace_xfs_attr_set_iter_return(attr->xattri_dela_state, args->dp);
return error;
}

diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
index 37db61649217..1749fd8f7ddd 100644
--- a/fs/xfs/libxfs/xfs_attr.h
+++ b/fs/xfs/libxfs/xfs_attr.h
@@ -452,15 +452,17 @@ enum xfs_delattr_state {
XFS_DAS_RM_SHRINK, /* We are shrinking the tree */

/* Leaf state set sequence */
- XFS_DAS_FOUND_LBLK, /* We found leaf blk for attr */
+ XFS_DAS_LEAF_SET_RMT, /* set a remote xattr from a leaf */
XFS_DAS_LEAF_ALLOC_RMT, /* We are allocating remote blocks */
+ XFS_DAS_LEAF_REPLACE, /* Perform replace ops on a leaf */
XFS_DAS_FLIP_LFLAG, /* Flipped leaf INCOMPLETE attr flag */
XFS_DAS_RM_LBLK, /* A rename is removing leaf blocks */
XFS_DAS_RD_LEAF, /* Read in the new leaf */

/* Node state set sequence, must match leaf state above */
- XFS_DAS_FOUND_NBLK, /* We found node blk for attr */
+ XFS_DAS_NODE_SET_RMT, /* set a remote xattr from a node */
XFS_DAS_NODE_ALLOC_RMT, /* We are allocating remote blocks */
+ XFS_DAS_NODE_REPLACE, /* Perform replace ops on a node */
XFS_DAS_FLIP_NFLAG, /* Flipped node INCOMPLETE attr flag */
XFS_DAS_RM_NBLK, /* A rename is removing node blocks */
XFS_DAS_CLR_FLAG, /* Clear incomplete flag */
@@ -476,13 +478,15 @@ enum xfs_delattr_state {
{ XFS_DAS_RMTBLK, "XFS_DAS_RMTBLK" }, \
{ XFS_DAS_RM_NAME, "XFS_DAS_RM_NAME" }, \
{ XFS_DAS_RM_SHRINK, "XFS_DAS_RM_SHRINK" }, \
- { XFS_DAS_FOUND_LBLK, "XFS_DAS_FOUND_LBLK" }, \
+ { XFS_DAS_LEAF_SET_RMT, "XFS_DAS_LEAF_SET_RMT" }, \
{ XFS_DAS_LEAF_ALLOC_RMT, "XFS_DAS_LEAF_ALLOC_RMT" }, \
- { XFS_DAS_FOUND_NBLK, "XFS_DAS_FOUND_NBLK" }, \
- { XFS_DAS_NODE_ALLOC_RMT, "XFS_DAS_NODE_ALLOC_RMT" }, \
+ { XFS_DAS_LEAF_REPLACE, "XFS_DAS_LEAF_REPLACE" }, \
{ XFS_DAS_FLIP_LFLAG, "XFS_DAS_FLIP_LFLAG" }, \
{ XFS_DAS_RM_LBLK, "XFS_DAS_RM_LBLK" }, \
{ XFS_DAS_RD_LEAF, "XFS_DAS_RD_LEAF" }, \
+ { XFS_DAS_NODE_SET_RMT, "XFS_DAS_NODE_SET_RMT" }, \
+ { XFS_DAS_NODE_ALLOC_RMT, "XFS_DAS_NODE_ALLOC_RMT" }, \
+ { XFS_DAS_NODE_REPLACE, "XFS_DAS_NODE_REPLACE" }, \
{ XFS_DAS_FLIP_NFLAG, "XFS_DAS_FLIP_NFLAG" }, \
{ XFS_DAS_RM_NBLK, "XFS_DAS_RM_NBLK" }, \
{ XFS_DAS_CLR_FLAG, "XFS_DAS_CLR_FLAG" }, \
diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
index 067ab31d7a20..cb9122327114 100644
--- a/fs/xfs/xfs_trace.h
+++ b/fs/xfs/xfs_trace.h
@@ -4136,13 +4136,15 @@ TRACE_DEFINE_ENUM(XFS_DAS_NODE_ADD);
TRACE_DEFINE_ENUM(XFS_DAS_RMTBLK);
TRACE_DEFINE_ENUM(XFS_DAS_RM_NAME);
TRACE_DEFINE_ENUM(XFS_DAS_RM_SHRINK);
-TRACE_DEFINE_ENUM(XFS_DAS_FOUND_LBLK);
+TRACE_DEFINE_ENUM(XFS_DAS_LEAF_SET_RMT);
TRACE_DEFINE_ENUM(XFS_DAS_LEAF_ALLOC_RMT);
-TRACE_DEFINE_ENUM(XFS_DAS_FOUND_NBLK);
-TRACE_DEFINE_ENUM(XFS_DAS_NODE_ALLOC_RMT);
+TRACE_DEFINE_ENUM(XFS_DAS_LEAF_REPLACE);
TRACE_DEFINE_ENUM(XFS_DAS_FLIP_LFLAG);
TRACE_DEFINE_ENUM(XFS_DAS_RM_LBLK);
TRACE_DEFINE_ENUM(XFS_DAS_RD_LEAF);
+TRACE_DEFINE_ENUM(XFS_DAS_NODE_SET_RMT);
+TRACE_DEFINE_ENUM(XFS_DAS_NODE_ALLOC_RMT);
+TRACE_DEFINE_ENUM(XFS_DAS_NODE_REPLACE);
TRACE_DEFINE_ENUM(XFS_DAS_FLIP_NFLAG);
TRACE_DEFINE_ENUM(XFS_DAS_RM_NBLK);
TRACE_DEFINE_ENUM(XFS_DAS_CLR_FLAG);
@@ -4172,6 +4174,7 @@ DEFINE_DAS_STATE_EVENT(xfs_attr_set_iter_return);
DEFINE_DAS_STATE_EVENT(xfs_attr_leaf_addname_return);
DEFINE_DAS_STATE_EVENT(xfs_attr_node_addname_return);
DEFINE_DAS_STATE_EVENT(xfs_attr_remove_iter_return);
+DEFINE_DAS_STATE_EVENT(xfs_attr_rmtval_alloc);
DEFINE_DAS_STATE_EVENT(xfs_attr_rmtval_remove_return);
DEFINE_DAS_STATE_EVENT(xfs_attr_defer_add);
DEFINE_DAS_STATE_EVENT(xfs_attr_defer_replace);
--
2.35.1