[PATCH 10/25] xfs: introduce a swap-extent log intent item

Darrick J. Wong
2023-12-31T20:26:51Z

Introduce a new intent log item to handle swapping extents.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/Makefile | 1
fs/xfs/libxfs/xfs_log_format.h | 51 ++++++++
fs/xfs/libxfs/xfs_log_recover.h | 2
fs/xfs/xfs_log_recover.c | 2
fs/xfs/xfs_super.c | 19 +++
fs/xfs/xfs_swapext_item.c | 236 +++++++++++++++++++++++++++++++++++++++
fs/xfs/xfs_swapext_item.h | 56 +++++++++
7 files changed, 364 insertions(+), 3 deletions(-)
create mode 100644 fs/xfs/xfs_swapext_item.c
create mode 100644 fs/xfs/xfs_swapext_item.h

diff --git a/fs/xfs/Makefile b/fs/xfs/Makefile
index d0b538c11faaf..95f9b32d947c4 100644
--- a/fs/xfs/Makefile
+++ b/fs/xfs/Makefile
@@ -111,6 +111,7 @@ xfs-y += xfs_log.o \
xfs_iunlink_item.o \
xfs_refcount_item.o \
xfs_rmap_item.o \
+ xfs_swapext_item.o \
xfs_log_recover.o \
xfs_trans_ail.o \
xfs_trans_buf.o
diff --git a/fs/xfs/libxfs/xfs_log_format.h b/fs/xfs/libxfs/xfs_log_format.h
index 16872972e1e97..24c3d5dc36182 100644
--- a/fs/xfs/libxfs/xfs_log_format.h
+++ b/fs/xfs/libxfs/xfs_log_format.h
@@ -117,8 +117,9 @@ struct xfs_unmount_log_format {
#define XLOG_REG_TYPE_ATTRD_FORMAT 28
#define XLOG_REG_TYPE_ATTR_NAME 29
#define XLOG_REG_TYPE_ATTR_VALUE 30
-#define XLOG_REG_TYPE_MAX 30
-
+#define XLOG_REG_TYPE_SXI_FORMAT 31
+#define XLOG_REG_TYPE_SXD_FORMAT 32
+#define XLOG_REG_TYPE_MAX 32

/*
* Flags to log operation header
@@ -243,6 +244,8 @@ typedef struct xfs_trans_header {
#define XFS_LI_BUD 0x1245
#define XFS_LI_ATTRI 0x1246 /* attr set/remove intent*/
#define XFS_LI_ATTRD 0x1247 /* attr set/remove done */
+#define XFS_LI_SXI 0x1248 /* extent swap intent */
+#define XFS_LI_SXD 0x1249 /* extent swap done */

#define XFS_LI_TYPE_DESC \
{ XFS_LI_EFI, "XFS_LI_EFI" }, \
@@ -260,7 +263,9 @@ typedef struct xfs_trans_header {
{ XFS_LI_BUI, "XFS_LI_BUI" }, \
{ XFS_LI_BUD, "XFS_LI_BUD" }, \
{ XFS_LI_ATTRI, "XFS_LI_ATTRI" }, \
- { XFS_LI_ATTRD, "XFS_LI_ATTRD" }
+ { XFS_LI_ATTRD, "XFS_LI_ATTRD" }, \
+ { XFS_LI_SXI, "XFS_LI_SXI" }, \
+ { XFS_LI_SXD, "XFS_LI_SXD" }

/*
* Inode Log Item Format definitions.
@@ -878,6 +883,46 @@ struct xfs_bud_log_format {
uint64_t bud_bui_id; /* id of corresponding bui */
};

+/*
+ * SXI/SXD (extent swapping) log format definitions
+ */
+
+struct xfs_swap_extent {
+ uint64_t sx_inode1;
+ uint64_t sx_inode2;
+ uint64_t sx_startoff1;
+ uint64_t sx_startoff2;
+ uint64_t sx_blockcount;
+ uint64_t sx_flags;
+ int64_t sx_isize1;
+ int64_t sx_isize2;
+};
+
+#define XFS_SWAP_EXT_FLAGS (0)
+
+#define XFS_SWAP_EXT_STRINGS
+
+/* This is the structure used to lay out an sxi log item in the log. */
+struct xfs_sxi_log_format {
+ uint16_t sxi_type; /* sxi log item type */
+ uint16_t sxi_size; /* size of this item */
+ uint32_t __pad; /* must be zero */
+ uint64_t sxi_id; /* sxi identifier */
+ struct xfs_swap_extent sxi_extent; /* extent to swap */
+};
+
+/*
+ * This is the structure used to lay out an sxd log item in the
+ * log. The sxd_extents array is a variable size array whose
+ * size is given by sxd_nextents;
+ */
+struct xfs_sxd_log_format {
+ uint16_t sxd_type; /* sxd log item type */
+ uint16_t sxd_size; /* size of this item */
+ uint32_t __pad;
+ uint64_t sxd_sxi_id; /* id of corresponding bui */
+};
+
/*
* Dquot Log format definitions.
*
diff --git a/fs/xfs/libxfs/xfs_log_recover.h b/fs/xfs/libxfs/xfs_log_recover.h
index 9fe7a9564bca9..891221b0b83aa 100644
--- a/fs/xfs/libxfs/xfs_log_recover.h
+++ b/fs/xfs/libxfs/xfs_log_recover.h
@@ -75,6 +75,8 @@ extern const struct xlog_recover_item_ops xlog_cui_item_ops;
extern const struct xlog_recover_item_ops xlog_cud_item_ops;
extern const struct xlog_recover_item_ops xlog_attri_item_ops;
extern const struct xlog_recover_item_ops xlog_attrd_item_ops;
+extern const struct xlog_recover_item_ops xlog_sxi_item_ops;
+extern const struct xlog_recover_item_ops xlog_sxd_item_ops;

/*
* Macros, structures, prototypes for internal log manager use.
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 6048f1b08acc0..628d7915120b0 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -1790,6 +1790,8 @@ static const struct xlog_recover_item_ops *xlog_recover_item_ops[] = {
&xlog_bud_item_ops,
&xlog_attri_item_ops,
&xlog_attrd_item_ops,
+ &xlog_sxi_item_ops,
+ &xlog_sxd_item_ops,
};

static const struct xlog_recover_item_ops *
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index d535445129752..e6e8e8fb17a19 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -43,6 +43,7 @@
#include "xfs_iunlink_item.h"
#include "xfs_dahash_test.h"
#include "xfs_rtbitmap.h"
+#include "xfs_swapext_item.h"
#include "scrub/stats.h"
#include "scrub/rcbag_btree.h"

@@ -2196,8 +2197,24 @@ xfs_init_caches(void)
if (!xfs_iunlink_cache)
goto out_destroy_attri_cache;

+ xfs_sxd_cache = kmem_cache_create("xfs_sxd_item",
+ sizeof(struct xfs_sxd_log_item),
+ 0, 0, NULL);
+ if (!xfs_sxd_cache)
+ goto out_destroy_iul_cache;
+
+ xfs_sxi_cache = kmem_cache_create("xfs_sxi_item",
+ sizeof(struct xfs_sxi_log_item),
+ 0, 0, NULL);
+ if (!xfs_sxi_cache)
+ goto out_destroy_sxd_cache;
+
return 0;

+ out_destroy_sxd_cache:
+ kmem_cache_destroy(xfs_sxd_cache);
+ out_destroy_iul_cache:
+ kmem_cache_destroy(xfs_iunlink_cache);
out_destroy_attri_cache:
kmem_cache_destroy(xfs_attri_cache);
out_destroy_attrd_cache:
@@ -2254,6 +2271,8 @@ xfs_destroy_caches(void)
* destroy caches.
*/
rcu_barrier();
+ kmem_cache_destroy(xfs_sxd_cache);
+ kmem_cache_destroy(xfs_sxi_cache);
kmem_cache_destroy(xfs_iunlink_cache);
kmem_cache_destroy(xfs_attri_cache);
kmem_cache_destroy(xfs_attrd_cache);
diff --git a/fs/xfs/xfs_swapext_item.c b/fs/xfs/xfs_swapext_item.c
new file mode 100644
index 0000000000000..0117735913cf1
--- /dev/null
+++ b/fs/xfs/xfs_swapext_item.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2020-2024 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_shared.h"
+#include "xfs_mount.h"
+#include "xfs_defer.h"
+#include "xfs_inode.h"
+#include "xfs_trans.h"
+#include "xfs_trans_priv.h"
+#include "xfs_swapext_item.h"
+#include "xfs_log.h"
+#include "xfs_bmap.h"
+#include "xfs_icache.h"
+#include "xfs_trans_space.h"
+#include "xfs_error.h"
+#include "xfs_log_priv.h"
+#include "xfs_log_recover.h"
+
+struct kmem_cache *xfs_sxi_cache;
+struct kmem_cache *xfs_sxd_cache;
+
+static const struct xfs_item_ops xfs_sxi_item_ops;
+
+static inline struct xfs_sxi_log_item *SXI_ITEM(struct xfs_log_item *lip)
+{
+ return container_of(lip, struct xfs_sxi_log_item, sxi_item);
+}
+
+STATIC void
+xfs_sxi_item_free(
+ struct xfs_sxi_log_item *sxi_lip)
+{
+ kmem_free(sxi_lip->sxi_item.li_lv_shadow);
+ kmem_cache_free(xfs_sxi_cache, sxi_lip);
+}
+
+/*
+ * Freeing the SXI requires that we remove it from the AIL if it has already
+ * been placed there. However, the SXI may not yet have been placed in the AIL
+ * when called by xfs_sxi_release() from SXD processing due to the ordering of
+ * committed vs unpin operations in bulk insert operations. Hence the reference
+ * count to ensure only the last caller frees the SXI.
+ */
+STATIC void
+xfs_sxi_release(
+ struct xfs_sxi_log_item *sxi_lip)
+{
+ ASSERT(atomic_read(&sxi_lip->sxi_refcount) > 0);
+ if (atomic_dec_and_test(&sxi_lip->sxi_refcount)) {
+ xfs_trans_ail_delete(&sxi_lip->sxi_item, 0);
+ xfs_sxi_item_free(sxi_lip);
+ }
+}
+
+
+STATIC void
+xfs_sxi_item_size(
+ struct xfs_log_item *lip,
+ int *nvecs,
+ int *nbytes)
+{
+ *nvecs += 1;
+ *nbytes += sizeof(struct xfs_sxi_log_format);
+}
+
+/*
+ * This is called to fill in the vector of log iovecs for the given sxi log
+ * item. We use only 1 iovec, and we point that at the sxi_log_format structure
+ * embedded in the sxi item.
+ */
+STATIC void
+xfs_sxi_item_format(
+ struct xfs_log_item *lip,
+ struct xfs_log_vec *lv)
+{
+ struct xfs_sxi_log_item *sxi_lip = SXI_ITEM(lip);
+ struct xfs_log_iovec *vecp = NULL;
+
+ sxi_lip->sxi_format.sxi_type = XFS_LI_SXI;
+ sxi_lip->sxi_format.sxi_size = 1;
+
+ xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_SXI_FORMAT,
+ &sxi_lip->sxi_format,
+ sizeof(struct xfs_sxi_log_format));
+}
+
+/*
+ * The unpin operation is the last place an SXI is manipulated in the log. It
+ * is either inserted in the AIL or aborted in the event of a log I/O error. In
+ * either case, the SXI transaction has been successfully committed to make it
+ * this far. Therefore, we expect whoever committed the SXI to either construct
+ * and commit the SXD or drop the SXD's reference in the event of error. Simply
+ * drop the log's SXI reference now that the log is done with it.
+ */
+STATIC void
+xfs_sxi_item_unpin(
+ struct xfs_log_item *lip,
+ int remove)
+{
+ struct xfs_sxi_log_item *sxi_lip = SXI_ITEM(lip);
+
+ xfs_sxi_release(sxi_lip);
+}
+
+/*
+ * The SXI has been either committed or aborted if the transaction has been
+ * cancelled. If the transaction was cancelled, an SXD isn't going to be
+ * constructed and thus we free the SXI here directly.
+ */
+STATIC void
+xfs_sxi_item_release(
+ struct xfs_log_item *lip)
+{
+ xfs_sxi_release(SXI_ITEM(lip));
+}
+
+/* Allocate and initialize an sxi item with the given number of extents. */
+STATIC struct xfs_sxi_log_item *
+xfs_sxi_init(
+ struct xfs_mount *mp)
+
+{
+ struct xfs_sxi_log_item *sxi_lip;
+
+ sxi_lip = kmem_cache_zalloc(xfs_sxi_cache, GFP_KERNEL | __GFP_NOFAIL);
+
+ xfs_log_item_init(mp, &sxi_lip->sxi_item, XFS_LI_SXI, &xfs_sxi_item_ops);
+ sxi_lip->sxi_format.sxi_id = (uintptr_t)(void *)sxi_lip;
+ atomic_set(&sxi_lip->sxi_refcount, 2);
+
+ return sxi_lip;
+}
+
+static inline struct xfs_sxd_log_item *SXD_ITEM(struct xfs_log_item *lip)
+{
+ return container_of(lip, struct xfs_sxd_log_item, sxd_item);
+}
+
+STATIC bool
+xfs_sxi_item_match(
+ struct xfs_log_item *lip,
+ uint64_t intent_id)
+{
+ return SXI_ITEM(lip)->sxi_format.sxi_id == intent_id;
+}
+
+static const struct xfs_item_ops xfs_sxi_item_ops = {
+ .flags = XFS_ITEM_INTENT,
+ .iop_size = xfs_sxi_item_size,
+ .iop_format = xfs_sxi_item_format,
+ .iop_unpin = xfs_sxi_item_unpin,
+ .iop_release = xfs_sxi_item_release,
+ .iop_match = xfs_sxi_item_match,
+};
+
+/*
+ * This routine is called to create an in-core extent swapext update item from
+ * the sxi format structure which was logged on disk. It allocates an in-core
+ * sxi, copies the extents from the format structure into it, and adds the sxi
+ * to the AIL with the given LSN.
+ */
+STATIC int
+xlog_recover_sxi_commit_pass2(
+ struct xlog *log,
+ struct list_head *buffer_list,
+ struct xlog_recover_item *item,
+ xfs_lsn_t lsn)
+{
+ struct xfs_mount *mp = log->l_mp;
+ struct xfs_sxi_log_item *sxi_lip;
+ struct xfs_sxi_log_format *sxi_formatp;
+ size_t len;
+
+ sxi_formatp = item->ri_buf[0].i_addr;
+
+ if (sxi_formatp->__pad != 0) {
+ XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
+ return -EFSCORRUPTED;
+ }
+
+ len = sizeof(struct xfs_sxi_log_format);
+ if (item->ri_buf[0].i_len != len) {
+ XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
+ return -EFSCORRUPTED;
+ }
+
+ sxi_lip = xfs_sxi_init(mp);
+ memcpy(&sxi_lip->sxi_format, sxi_formatp, len);
+
+ /* not implemented yet */
+ return -EIO;
+}
+
+const struct xlog_recover_item_ops xlog_sxi_item_ops = {
+ .item_type = XFS_LI_SXI,
+ .commit_pass2 = xlog_recover_sxi_commit_pass2,
+};
+
+/*
+ * This routine is called when an SXD format structure is found in a committed
+ * transaction in the log. Its purpose is to cancel the corresponding SXI if it
+ * was still in the log. To do this it searches the AIL for the SXI with an id
+ * equal to that in the SXD format structure. If we find it we drop the SXD
+ * reference, which removes the SXI from the AIL and frees it.
+ */
+STATIC int
+xlog_recover_sxd_commit_pass2(
+ struct xlog *log,
+ struct list_head *buffer_list,
+ struct xlog_recover_item *item,
+ xfs_lsn_t lsn)
+{
+ struct xfs_sxd_log_format *sxd_formatp;
+
+ sxd_formatp = item->ri_buf[0].i_addr;
+ if (item->ri_buf[0].i_len != sizeof(struct xfs_sxd_log_format)) {
+ XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
+ return -EFSCORRUPTED;
+ }
+
+ xlog_recover_release_intent(log, XFS_LI_SXI, sxd_formatp->sxd_sxi_id);
+ return 0;
+}
+
+const struct xlog_recover_item_ops xlog_sxd_item_ops = {
+ .item_type = XFS_LI_SXD,
+ .commit_pass2 = xlog_recover_sxd_commit_pass2,
+};
diff --git a/fs/xfs/xfs_swapext_item.h b/fs/xfs/xfs_swapext_item.h
new file mode 100644
index 0000000000000..d816ab842a603
--- /dev/null
+++ b/fs/xfs/xfs_swapext_item.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (c) 2020-2024 Oracle. All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#ifndef __XFS_SWAPEXT_ITEM_H__
+#define __XFS_SWAPEXT_ITEM_H__
+
+/*
+ * The extent swapping intent item help us perform atomic extent swaps between
+ * two inode forks. It does this by tracking the range of logical offsets that
+ * still need to be swapped, and relogs as progress happens.
+ *
+ * *I items should be recorded in the *first* of a series of rolled
+ * transactions, and the *D items should be recorded in the same transaction
+ * that records the associated bmbt updates.
+ *
+ * Should the system crash after the commit of the first transaction but
+ * before the commit of the final transaction in a series, log recovery will
+ * use the redo information recorded by the intent items to replay the
+ * rest of the extent swaps.
+ */
+
+/* kernel only SXI/SXD definitions */
+
+struct xfs_mount;
+struct kmem_cache;
+
+/*
+ * This is the "swapext update intent" log item. It is used to log the fact
+ * that we are swapping extents between two files. It is used in conjunction
+ * with the "swapext update done" log item described below.
+ *
+ * These log items follow the same rules as struct xfs_efi_log_item; see the
+ * comments about that structure (in xfs_extfree_item.h) for more details.
+ */
+struct xfs_sxi_log_item {
+ struct xfs_log_item sxi_item;
+ atomic_t sxi_refcount;
+ struct xfs_sxi_log_format sxi_format;
+};
+
+/*
+ * This is the "swapext update done" log item. It is used to log the fact that
+ * some extent swapping mentioned in an earlier sxi item have been performed.
+ */
+struct xfs_sxd_log_item {
+ struct xfs_log_item sxd_item;
+ struct xfs_sxi_log_item *sxd_intent_log_item;
+ struct xfs_sxd_log_format sxd_format;
+};
+
+extern struct kmem_cache *xfs_sxi_cache;
+extern struct kmem_cache *xfs_sxd_cache;
+
+#endif /* __XFS_SWAPEXT_ITEM_H__ */