On Thu, 2022-04-14 at 19:44 +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> When we set a new xattr, we have three exit paths:
>
> 1. nothign 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. nothign 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.
>
>
Looks like it should retain the same code flow. I can follow it, but I
feel like I'm the only one reviewing this? As long as folks are ok
with the new code flow, I'm fine with it.
Reviewed-by: Allison Henderson<allison.henderson@xxxxxxxxxx>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
> ---
> 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 655e4388dfec..4b9c107fe5de 100644
> --- a/fs/xfs/libxfs/xfs_attr.c
> +++ b/fs/xfs/libxfs/xfs_attr.c
> @@ -347,9 +347,11 @@ 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;
> @@ -376,9 +378,11 @@ 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;
> @@ -388,6 +392,40 @@ 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.
> @@ -419,54 +457,26 @@ 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
> @@ -484,10 +494,9 @@ 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++;
> @@ -562,6 +571,8 @@ 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 0ad78f9279ac..1de6c06b7f19 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 8739cc1e0561..cf99efc5ba5a 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -4105,13 +4105,15 @@ 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);
> @@ -4141,6 +4143,7 @@
> 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);
>
> TRACE_EVENT(xfs_force_shutdown,
