On Thu, 2022-04-14 at 19:44 +1000, Dave Chinner wrote:
> From: Dave Chinner <dchinner@xxxxxxxxxx>
>
> We may not have a remote value for the old xattr we have to remove,
> so skip over the remote value removal states and go straight to
> the xattr name removal in the leaf/node block.
>
> Signed-off-by: Dave Chinner <dchinner@xxxxxxxxxx>
Ok, I can follow it. I may try and think of a new way to try and
illustrate it though as it is not nearly as linear as it used to be,
but I don't think that's a bad thing.
Reviewed-by: Allison Henderson<allison.henderson@xxxxxxxxxx>
> ---
> fs/xfs/libxfs/xfs_attr.c | 59 ++++++++++++++++++++----------------
> ----
> fs/xfs/libxfs/xfs_attr.h | 8 +++---
> fs/xfs/xfs_trace.h | 4 +--
> 3 files changed, 36 insertions(+), 35 deletions(-)
>
> diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
> index c72f98794bb3..8762d3a0605a 100644
> --- a/fs/xfs/libxfs/xfs_attr.c
> +++ b/fs/xfs/libxfs/xfs_attr.c
> @@ -510,15 +510,14 @@ xfs_attr_set_iter(
> /*
> * We must "flip" the incomplete flags on the "new" and
> "old"
> * attribute/value pairs so that one disappears and one
> appears
> - * atomically. Then we must remove the "old"
> attribute/value
> - * pair.
> + * atomically.
> */
> error = xfs_attr3_leaf_flipflags(args);
> if (error)
> return error;
> /*
> - * Commit the flag value change and start the next
> trans
> - * in series at REMOVE_OLD.
> + * We must commit the flag value change now to make it
> atomic
> + * and then we can start the next trans in series at
> REMOVE_OLD.
> */
> error = -EAGAIN;
> attr->xattri_dela_state++;
> @@ -527,41 +526,43 @@ xfs_attr_set_iter(
> case XFS_DAS_LEAF_REMOVE_OLD:
> case XFS_DAS_NODE_REMOVE_OLD:
> /*
> - * Dismantle the "old" attribute/value pair by removing
> a
> - * "remote" value (if it exists).
> + * If we have a remote attr, start the process of
> removing it
> + * by invalidating any cached buffers.
> + *
> + * If we don't have a remote attr, we skip the remote
> block
> + * removal state altogether with a second state
> increment.
> */
> xfs_attr_restore_rmt_blk(args);
> - error = xfs_attr_rmtval_invalidate(args);
> - if (error)
> - return error;
> -
> - attr->xattri_dela_state++;
> - fallthrough;
> - case XFS_DAS_RM_LBLK:
> - case XFS_DAS_RM_NBLK:
> if (args->rmtblkno) {
> - error = xfs_attr_rmtval_remove(attr);
> - if (error == -EAGAIN)
> - trace_xfs_attr_set_iter_return(
> - attr->xattri_dela_state, args-
> >dp);
> + error = xfs_attr_rmtval_invalidate(args);
> if (error)
> return error;
> -
> - attr->xattri_dela_state = XFS_DAS_RD_LEAF;
> - trace_xfs_attr_set_iter_return(attr-
> >xattri_dela_state,
> - args->dp);
> - return -EAGAIN;
> + } else {
> + attr->xattri_dela_state++;
> }
>
> + attr->xattri_dela_state++;
> + goto next_state;
> +
> + case XFS_DAS_LEAF_REMOVE_RMT:
> + case XFS_DAS_NODE_REMOVE_RMT:
> + error = xfs_attr_rmtval_remove(attr);
> + if (error == -EAGAIN)
> + break;
> + if (error)
> + return error;
> +
> /*
> - * This is the end of the shared leaf/node sequence. We
> need
> - * to continue at the next state in the sequence, but
> we can't
> - * easily just fall through. So we increment to the
> next state
> - * and then jump back to switch statement to evaluate
> the next
> - * state correctly.
> + * We've finished removing the remote attr blocks, so
> commit the
> + * transaction and move on to removing the attr name
> from the
> + * leaf/node block. Removing the attr might require a
> full
> + * transaction reservation for btree block freeing, so
> we
> + * can't do that in the same transaction where we
> removed the
> + * remote attr blocks.
> */
> + error = -EAGAIN;
> attr->xattri_dela_state++;
> - goto next_state;
> + break;
>
> case XFS_DAS_RD_LEAF:
> /*
> diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
> index a4ff0a2305d6..18e157bf19cb 100644
> --- a/fs/xfs/libxfs/xfs_attr.h
> +++ b/fs/xfs/libxfs/xfs_attr.h
> @@ -456,7 +456,7 @@ enum xfs_delattr_state {
> XFS_DAS_LEAF_ALLOC_RMT, /* We are allocating remote
> blocks */
> XFS_DAS_LEAF_REPLACE, /* Perform replace ops on a
> leaf */
> XFS_DAS_LEAF_REMOVE_OLD, /* Start removing old attr from leaf
> */
> - XFS_DAS_RM_LBLK, /* A rename is removing leaf blocks
> */
> + XFS_DAS_LEAF_REMOVE_RMT, /* A rename is removing remote blocks
> */
> XFS_DAS_RD_LEAF, /* Read in the new leaf */
>
> /* Node state set sequence, must match leaf state above */
> @@ -464,7 +464,7 @@ enum xfs_delattr_state {
> XFS_DAS_NODE_ALLOC_RMT, /* We are allocating remote
> blocks */
> XFS_DAS_NODE_REPLACE, /* Perform replace ops on a
> node */
> XFS_DAS_NODE_REMOVE_OLD, /* Start removing old attr from node
> */
> - XFS_DAS_RM_NBLK, /* A rename is removing node blocks
> */
> + XFS_DAS_NODE_REMOVE_RMT, /* A rename is removing remote blocks
> */
> XFS_DAS_CLR_FLAG, /* Clear incomplete flag */
>
> XFS_DAS_DONE, /* finished operation */
> @@ -482,13 +482,13 @@ enum xfs_delattr_state {
> { XFS_DAS_LEAF_ALLOC_RMT, "XFS_DAS_LEAF_ALLOC_RMT" }, \
> { XFS_DAS_LEAF_REPLACE, "XFS_DAS_LEAF_REPLACE" }, \
> { XFS_DAS_LEAF_REMOVE_OLD, "XFS_DAS_LEAF_REMOVE_OLD" },
> \
> - { XFS_DAS_RM_LBLK, "XFS_DAS_RM_LBLK" }, \
> + { XFS_DAS_LEAF_REMOVE_RMT, "XFS_DAS_LEAF_REMOVE_RMT" },
> \
> { 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_NODE_REMOVE_OLD, "XFS_DAS_NODE_REMOVE_OLD" },
> \
> - { XFS_DAS_RM_NBLK, "XFS_DAS_RM_NBLK" }, \
> + { XFS_DAS_NODE_REMOVE_RMT, "XFS_DAS_NODE_REMOVE_RMT" },
> \
> { XFS_DAS_CLR_FLAG, "XFS_DAS_CLR_FLAG" }, \
> { XFS_DAS_DONE, "XFS_DAS_DONE" }
>
> diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h
> index a4b99c7f8ef0..91852b9721e4 100644
> --- a/fs/xfs/xfs_trace.h
> +++ b/fs/xfs/xfs_trace.h
> @@ -4109,13 +4109,13 @@ TRACE_DEFINE_ENUM(XFS_DAS_LEAF_SET_RMT);
> TRACE_DEFINE_ENUM(XFS_DAS_LEAF_ALLOC_RMT);
> TRACE_DEFINE_ENUM(XFS_DAS_LEAF_REPLACE);
> TRACE_DEFINE_ENUM(XFS_DAS_LEAF_REMOVE_OLD);
> -TRACE_DEFINE_ENUM(XFS_DAS_RM_LBLK);
> +TRACE_DEFINE_ENUM(XFS_DAS_LEAF_REMOVE_RMT);
> 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_NODE_REMOVE_OLD);
> -TRACE_DEFINE_ENUM(XFS_DAS_RM_NBLK);
> +TRACE_DEFINE_ENUM(XFS_DAS_NODE_REMOVE_RMT);
> TRACE_DEFINE_ENUM(XFS_DAS_CLR_FLAG);
>
> DECLARE_EVENT_CLASS(xfs_das_state_class,
