[PATCH v22 11/16] xfs: Add xfs_attr_set_deferred and xfs_attr_remove_deferred

Allison Henderson
2021-07-27T06:21:20Z

From: Allison Collins <allison.henderson@oracle.com>

These routines set up and queue a new deferred attribute operations.
These functions are meant to be called by any routine needing to
initiate a deferred attribute operation as opposed to the existing
inline operations. New helper function xfs_attr_item_init also added.

Finally enable delayed attributes in xfs_attr_set and xfs_attr_remove.

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/libxfs/xfs_attr.c | 70 +++++++++++++++++++++++++++++++++++++++++++++---
fs/xfs/libxfs/xfs_attr.h | 2 ++
fs/xfs/xfs_log.c | 41 ++++++++++++++++++++++++++++
fs/xfs/xfs_log.h | 1 +
4 files changed, 111 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index eee219c6..c447c21 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -25,6 +25,8 @@
#include "xfs_trans_space.h"
#include "xfs_trace.h"
#include "xfs_attr_item.h"
+#include "xfs_attr.h"
+#include "xfs_log.h"

/*
* xfs_attr.c
@@ -779,13 +781,19 @@ xfs_attr_set(
rmt_blks = xfs_attr3_rmt_blocks(mp, XFS_XATTR_SIZE_MAX);
}

+ if (xfs_hasdelattr(mp)) {
+ error = xfs_attr_use_log_assist(mp);
+ if (error)
+ return error;
+ }
+
/*
* Root fork attributes can use reserved data blocks for this
* operation if necessary
*/
error = xfs_trans_alloc_inode(dp, &tres, total, 0, rsvd, &args->trans);
if (error)
- return error;
+ goto drop_incompat;

if (args->value || xfs_inode_hasattr(dp)) {
error = xfs_iext_count_may_overflow(dp, XFS_ATTR_FORK,
@@ -803,9 +811,10 @@ xfs_attr_set(
if (error != -ENOATTR && error != -EEXIST)
goto out_trans_cancel;

- error = xfs_attr_set_args(args);
+ error = xfs_attr_set_deferred(args);
if (error)
goto out_trans_cancel;
+
/* shortform attribute has already been committed */
if (!args->trans)
goto out_unlock;
@@ -814,7 +823,7 @@ xfs_attr_set(
if (error != -EEXIST)
goto out_trans_cancel;

- error = xfs_attr_remove_args(args);
+ error = xfs_attr_remove_deferred(args);
if (error)
goto out_trans_cancel;
}
@@ -836,6 +845,9 @@ xfs_attr_set(
error = xfs_trans_commit(args->trans);
out_unlock:
xfs_iunlock(dp, XFS_ILOCK_EXCL);
+drop_incompat:
+ if (xfs_hasdelattr(mp))
+ xlog_drop_incompat_feat(mp->m_log);
return error;

out_trans_cancel:
@@ -844,6 +856,58 @@ xfs_attr_set(
goto out_unlock;
}

+STATIC int
+xfs_attr_item_init(
+ struct xfs_da_args *args,
+ unsigned int op_flags, /* op flag (set or remove) */
+ struct xfs_attr_item **attr) /* new xfs_attr_item */
+{
+
+ struct xfs_attr_item *new;
+
+ new = kmem_zalloc(sizeof(struct xfs_attr_item), KM_NOFS);
+ new->xattri_op_flags = op_flags;
+ new->xattri_dac.da_args = args;
+
+ *attr = new;
+ return 0;
+}
+
+/* Sets an attribute for an inode as a deferred operation */
+int
+xfs_attr_set_deferred(
+ struct xfs_da_args *args)
+{
+ struct xfs_attr_item *new;
+ int error = 0;
+
+ error = xfs_attr_item_init(args, XFS_ATTR_OP_FLAGS_SET, &new);
+ if (error)
+ return error;
+
+ xfs_defer_add(args->trans, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list);
+
+ return 0;
+}
+
+/* Removes an attribute for an inode as a deferred operation */
+int
+xfs_attr_remove_deferred(
+ struct xfs_da_args *args)
+{
+
+ struct xfs_attr_item *new;
+ int error;
+
+ error = xfs_attr_item_init(args, XFS_ATTR_OP_FLAGS_REMOVE, &new);
+ if (error)
+ return error;
+
+ xfs_defer_add(args->trans, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list);
+
+ return 0;
+}
+
/*========================================================================
* External routines when attribute list is inside the inode
*========================================================================*/
diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
index 463b2be..72b0ea5 100644
--- a/fs/xfs/libxfs/xfs_attr.h
+++ b/fs/xfs/libxfs/xfs_attr.h
@@ -527,5 +527,7 @@ bool xfs_attr_namecheck(const void *name, size_t length);
void xfs_delattr_context_init(struct xfs_delattr_context *dac,
struct xfs_da_args *args);
int xfs_attr_calc_size(struct xfs_da_args *args, int *local);
+int xfs_attr_set_deferred(struct xfs_da_args *args);
+int xfs_attr_remove_deferred(struct xfs_da_args *args);

#endif /* __XFS_ATTR_H__ */
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 7c593d9..216de6c 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -3948,3 +3948,44 @@ xlog_drop_incompat_feat(
{
up_read(&log->l_incompat_users);
}
+
+/*
+ * Get permission to use log-assisted atomic exchange of file extents.
+ *
+ * Callers must not be running any transactions or hold any inode locks, and
+ * they must release the permission by calling xlog_drop_incompat_feat
+ * when they're done.
+ */
+int
+xfs_attr_use_log_assist(
+ struct xfs_mount *mp)
+{
+ int error = 0;
+
+ /*
+ * Protect ourselves from an idle log clearing the logged xattrs log
+ * incompat feature bit.
+ */
+ xlog_use_incompat_feat(mp->m_log);
+
+ /*
+ * If log-assisted xattrs are already enabled, the caller can use the
+ * log assisted swap functions with the log-incompat reference we got.
+ */
+ if (xfs_sb_version_hasdelattr(&mp->m_sb))
+ return 0;
+
+ /* Enable log-assisted xattrs. */
+ xfs_warn_once(mp,
+"EXPERIMENTAL logged extended attributes feature added. Use at your own risk!");
+
+ error = xfs_add_incompat_log_feature(mp,
+ XFS_SB_FEAT_INCOMPAT_LOG_DELATTR);
+ if (error)
+ goto drop_incompat;
+
+ return 0;
+drop_incompat:
+ xlog_drop_incompat_feat(mp->m_log);
+ return error;
+}
diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index b274fb9..1e461671 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -144,5 +144,6 @@ xfs_lsn_t xlog_grant_push_threshold(struct xlog *log, int need_bytes);

void xlog_use_incompat_feat(struct xlog *log);
void xlog_drop_incompat_feat(struct xlog *log);
+int xfs_attr_use_log_assist(struct xfs_mount *mp);

#endif /* __XFS_LOG_H__ */
--
2.7.4