linux/fs/xfs/xfs_refcount_item.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2016 Oracle. All Rights Reserved.
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*/
#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_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_refcount_item.h"
#include "xfs_log.h"
#include "xfs_refcount.h"
#include "xfs_error.h"
#include "xfs_log_priv.h"
#include "xfs_log_recover.h"
struct kmem_cache *xfs_cui_cache;
struct kmem_cache *xfs_cud_cache;
static const struct xfs_item_ops xfs_cui_item_ops;
static inline struct xfs_cui_log_item *CUI_ITEM(struct xfs_log_item *lip)
{
return container_of(lip, struct xfs_cui_log_item, cui_item);
}
STATIC void
xfs_cui_item_free(
struct xfs_cui_log_item *cuip)
{
kmem_free(cuip->cui_item.li_lv_shadow);
if (cuip->cui_format.cui_nextents > XFS_CUI_MAX_FAST_EXTENTS)
kmem_free(cuip);
else
kmem_cache_free(xfs_cui_cache, cuip);
}
/*
* Freeing the CUI requires that we remove it from the AIL if it has already
* been placed there. However, the CUI may not yet have been placed in the AIL
* when called by xfs_cui_release() from CUD 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 CUI.
*/
STATIC void
xfs_cui_release(
struct xfs_cui_log_item *cuip)
{
ASSERT(atomic_read(&cuip->cui_refcount) > 0);
if (!atomic_dec_and_test(&cuip->cui_refcount))
return;
xfs_trans_ail_delete(&cuip->cui_item, 0);
xfs_cui_item_free(cuip);
}
STATIC void
xfs_cui_item_size(
struct xfs_log_item *lip,
int *nvecs,
int *nbytes)
{
struct xfs_cui_log_item *cuip = CUI_ITEM(lip);
*nvecs += 1;
*nbytes += xfs_cui_log_format_sizeof(cuip->cui_format.cui_nextents);
}
/*
* This is called to fill in the vector of log iovecs for the
* given cui log item. We use only 1 iovec, and we point that
* at the cui_log_format structure embedded in the cui item.
* It is at this point that we assert that all of the extent
* slots in the cui item have been filled.
*/
STATIC void
xfs_cui_item_format(
struct xfs_log_item *lip,
struct xfs_log_vec *lv)
{
struct xfs_cui_log_item *cuip = CUI_ITEM(lip);
struct xfs_log_iovec *vecp = NULL;
ASSERT(atomic_read(&cuip->cui_next_extent) ==
cuip->cui_format.cui_nextents);
cuip->cui_format.cui_type = XFS_LI_CUI;
cuip->cui_format.cui_size = 1;
xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_CUI_FORMAT, &cuip->cui_format,
xfs_cui_log_format_sizeof(cuip->cui_format.cui_nextents));
}
/*
* The unpin operation is the last place an CUI 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 CUI transaction has been successfully committed to make it
* this far. Therefore, we expect whoever committed the CUI to either construct
* and commit the CUD or drop the CUD's reference in the event of error. Simply
* drop the log's CUI reference now that the log is done with it.
*/
STATIC void
xfs_cui_item_unpin(
struct xfs_log_item *lip,
int remove)
{
struct xfs_cui_log_item *cuip = CUI_ITEM(lip);
xfs_cui_release(cuip);
}
/*
* The CUI has been either committed or aborted if the transaction has been
* cancelled. If the transaction was cancelled, an CUD isn't going to be
* constructed and thus we free the CUI here directly.
*/
STATIC void
xfs: split iop_unlock The iop_unlock method is called when comitting or cancelling a transaction. In the latter case, the transaction may or may not be aborted. While there is no known problem with the current code in practice, this implementation is limited in that any log item implementation that might want to differentiate between a commit and a cancellation must rely on the aborted state. The aborted bit is only set when the cancelled transaction is dirty, however. This means that there is no way to distinguish between a commit and a clean transaction cancellation. For example, intent log items currently rely on this distinction. The log item is either transferred to the CIL on commit or released on transaction cancel. There is currently no possibility for a clean intent log item in a transaction, but if that state is ever introduced a cancel of such a transaction will immediately result in memory leaks of the associated log item(s). This is an interface deficiency and landmine. To clean this up, replace the iop_unlock method with an iop_release method that is specific to transaction cancel. The existing iop_committing method occurs at the same time as iop_unlock in the commit path and there is no need for two separate callbacks here. Overload the iop_committing method with the current commit time iop_unlock implementations to eliminate the need for the latter and further simplify the interface. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-29 10:27:32 +08:00
xfs_cui_item_release(
struct xfs_log_item *lip)
{
xfs: split iop_unlock The iop_unlock method is called when comitting or cancelling a transaction. In the latter case, the transaction may or may not be aborted. While there is no known problem with the current code in practice, this implementation is limited in that any log item implementation that might want to differentiate between a commit and a cancellation must rely on the aborted state. The aborted bit is only set when the cancelled transaction is dirty, however. This means that there is no way to distinguish between a commit and a clean transaction cancellation. For example, intent log items currently rely on this distinction. The log item is either transferred to the CIL on commit or released on transaction cancel. There is currently no possibility for a clean intent log item in a transaction, but if that state is ever introduced a cancel of such a transaction will immediately result in memory leaks of the associated log item(s). This is an interface deficiency and landmine. To clean this up, replace the iop_unlock method with an iop_release method that is specific to transaction cancel. The existing iop_committing method occurs at the same time as iop_unlock in the commit path and there is no need for two separate callbacks here. Overload the iop_committing method with the current commit time iop_unlock implementations to eliminate the need for the latter and further simplify the interface. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-29 10:27:32 +08:00
xfs_cui_release(CUI_ITEM(lip));
}
/*
* Allocate and initialize an cui item with the given number of extents.
*/
STATIC struct xfs_cui_log_item *
xfs_cui_init(
struct xfs_mount *mp,
uint nextents)
{
struct xfs_cui_log_item *cuip;
ASSERT(nextents > 0);
if (nextents > XFS_CUI_MAX_FAST_EXTENTS)
cuip = kmem_zalloc(xfs_cui_log_item_sizeof(nextents),
0);
else
cuip = kmem_cache_zalloc(xfs_cui_cache,
GFP_KERNEL | __GFP_NOFAIL);
xfs_log_item_init(mp, &cuip->cui_item, XFS_LI_CUI, &xfs_cui_item_ops);
cuip->cui_format.cui_nextents = nextents;
cuip->cui_format.cui_id = (uintptr_t)(void *)cuip;
atomic_set(&cuip->cui_next_extent, 0);
atomic_set(&cuip->cui_refcount, 2);
return cuip;
}
static inline struct xfs_cud_log_item *CUD_ITEM(struct xfs_log_item *lip)
{
return container_of(lip, struct xfs_cud_log_item, cud_item);
}
STATIC void
xfs_cud_item_size(
struct xfs_log_item *lip,
int *nvecs,
int *nbytes)
{
*nvecs += 1;
*nbytes += sizeof(struct xfs_cud_log_format);
}
/*
* This is called to fill in the vector of log iovecs for the
* given cud log item. We use only 1 iovec, and we point that
* at the cud_log_format structure embedded in the cud item.
* It is at this point that we assert that all of the extent
* slots in the cud item have been filled.
*/
STATIC void
xfs_cud_item_format(
struct xfs_log_item *lip,
struct xfs_log_vec *lv)
{
struct xfs_cud_log_item *cudp = CUD_ITEM(lip);
struct xfs_log_iovec *vecp = NULL;
cudp->cud_format.cud_type = XFS_LI_CUD;
cudp->cud_format.cud_size = 1;
xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_CUD_FORMAT, &cudp->cud_format,
sizeof(struct xfs_cud_log_format));
}
/*
* The CUD is either committed or aborted if the transaction is cancelled. If
* the transaction is cancelled, drop our reference to the CUI and free the
* CUD.
*/
STATIC void
xfs: split iop_unlock The iop_unlock method is called when comitting or cancelling a transaction. In the latter case, the transaction may or may not be aborted. While there is no known problem with the current code in practice, this implementation is limited in that any log item implementation that might want to differentiate between a commit and a cancellation must rely on the aborted state. The aborted bit is only set when the cancelled transaction is dirty, however. This means that there is no way to distinguish between a commit and a clean transaction cancellation. For example, intent log items currently rely on this distinction. The log item is either transferred to the CIL on commit or released on transaction cancel. There is currently no possibility for a clean intent log item in a transaction, but if that state is ever introduced a cancel of such a transaction will immediately result in memory leaks of the associated log item(s). This is an interface deficiency and landmine. To clean this up, replace the iop_unlock method with an iop_release method that is specific to transaction cancel. The existing iop_committing method occurs at the same time as iop_unlock in the commit path and there is no need for two separate callbacks here. Overload the iop_committing method with the current commit time iop_unlock implementations to eliminate the need for the latter and further simplify the interface. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-29 10:27:32 +08:00
xfs_cud_item_release(
struct xfs_log_item *lip)
{
struct xfs_cud_log_item *cudp = CUD_ITEM(lip);
xfs: split iop_unlock The iop_unlock method is called when comitting or cancelling a transaction. In the latter case, the transaction may or may not be aborted. While there is no known problem with the current code in practice, this implementation is limited in that any log item implementation that might want to differentiate between a commit and a cancellation must rely on the aborted state. The aborted bit is only set when the cancelled transaction is dirty, however. This means that there is no way to distinguish between a commit and a clean transaction cancellation. For example, intent log items currently rely on this distinction. The log item is either transferred to the CIL on commit or released on transaction cancel. There is currently no possibility for a clean intent log item in a transaction, but if that state is ever introduced a cancel of such a transaction will immediately result in memory leaks of the associated log item(s). This is an interface deficiency and landmine. To clean this up, replace the iop_unlock method with an iop_release method that is specific to transaction cancel. The existing iop_committing method occurs at the same time as iop_unlock in the commit path and there is no need for two separate callbacks here. Overload the iop_committing method with the current commit time iop_unlock implementations to eliminate the need for the latter and further simplify the interface. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-29 10:27:32 +08:00
xfs_cui_release(cudp->cud_cuip);
kmem_free(cudp->cud_item.li_lv_shadow);
kmem_cache_free(xfs_cud_cache, cudp);
}
static struct xfs_log_item *
xfs_cud_item_intent(
struct xfs_log_item *lip)
{
return &CUD_ITEM(lip)->cud_cuip->cui_item;
}
static const struct xfs_item_ops xfs_cud_item_ops = {
.flags = XFS_ITEM_RELEASE_WHEN_COMMITTED |
XFS_ITEM_INTENT_DONE,
.iop_size = xfs_cud_item_size,
.iop_format = xfs_cud_item_format,
xfs: split iop_unlock The iop_unlock method is called when comitting or cancelling a transaction. In the latter case, the transaction may or may not be aborted. While there is no known problem with the current code in practice, this implementation is limited in that any log item implementation that might want to differentiate between a commit and a cancellation must rely on the aborted state. The aborted bit is only set when the cancelled transaction is dirty, however. This means that there is no way to distinguish between a commit and a clean transaction cancellation. For example, intent log items currently rely on this distinction. The log item is either transferred to the CIL on commit or released on transaction cancel. There is currently no possibility for a clean intent log item in a transaction, but if that state is ever introduced a cancel of such a transaction will immediately result in memory leaks of the associated log item(s). This is an interface deficiency and landmine. To clean this up, replace the iop_unlock method with an iop_release method that is specific to transaction cancel. The existing iop_committing method occurs at the same time as iop_unlock in the commit path and there is no need for two separate callbacks here. Overload the iop_committing method with the current commit time iop_unlock implementations to eliminate the need for the latter and further simplify the interface. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-29 10:27:32 +08:00
.iop_release = xfs_cud_item_release,
.iop_intent = xfs_cud_item_intent,
};
static struct xfs_cud_log_item *
xfs_trans_get_cud(
struct xfs_trans *tp,
struct xfs_cui_log_item *cuip)
{
struct xfs_cud_log_item *cudp;
cudp = kmem_cache_zalloc(xfs_cud_cache, GFP_KERNEL | __GFP_NOFAIL);
xfs_log_item_init(tp->t_mountp, &cudp->cud_item, XFS_LI_CUD,
&xfs_cud_item_ops);
cudp->cud_cuip = cuip;
cudp->cud_format.cud_cui_id = cuip->cui_format.cui_id;
xfs_trans_add_item(tp, &cudp->cud_item);
return cudp;
}
/*
* Finish an refcount update and log it to the CUD. Note that the
* transaction is marked dirty regardless of whether the refcount
* update succeeds or fails to support the CUI/CUD lifecycle rules.
*/
static int
xfs_trans_log_finish_refcount_update(
struct xfs_trans *tp,
struct xfs_cud_log_item *cudp,
enum xfs_refcount_intent_type type,
xfs_fsblock_t startblock,
xfs_extlen_t blockcount,
xfs_fsblock_t *new_fsb,
xfs_extlen_t *new_len,
struct xfs_btree_cur **pcur)
{
int error;
error = xfs_refcount_finish_one(tp, type, startblock,
blockcount, new_fsb, new_len, pcur);
/*
* Mark the transaction dirty, even on error. This ensures the
* transaction is aborted, which:
*
* 1.) releases the CUI and frees the CUD
* 2.) shuts down the filesystem
*/
tp->t_flags |= XFS_TRANS_DIRTY | XFS_TRANS_HAS_INTENT_DONE;
set_bit(XFS_LI_DIRTY, &cudp->cud_item.li_flags);
return error;
}
/* Sort refcount intents by AG. */
static int
xfs_refcount_update_diff_items(
void *priv,
const struct list_head *a,
const struct list_head *b)
{
struct xfs_mount *mp = priv;
struct xfs_refcount_intent *ra;
struct xfs_refcount_intent *rb;
ra = container_of(a, struct xfs_refcount_intent, ri_list);
rb = container_of(b, struct xfs_refcount_intent, ri_list);
return XFS_FSB_TO_AGNO(mp, ra->ri_startblock) -
XFS_FSB_TO_AGNO(mp, rb->ri_startblock);
}
/* Set the phys extent flags for this reverse mapping. */
static void
xfs_trans_set_refcount_flags(
struct xfs_phys_extent *refc,
enum xfs_refcount_intent_type type)
{
refc->pe_flags = 0;
switch (type) {
case XFS_REFCOUNT_INCREASE:
case XFS_REFCOUNT_DECREASE:
case XFS_REFCOUNT_ALLOC_COW:
case XFS_REFCOUNT_FREE_COW:
refc->pe_flags |= type;
break;
default:
ASSERT(0);
}
}
/* Log refcount updates in the intent item. */
STATIC void
xfs_refcount_update_log_item(
struct xfs_trans *tp,
struct xfs_cui_log_item *cuip,
struct xfs_refcount_intent *refc)
{
uint next_extent;
struct xfs_phys_extent *ext;
tp->t_flags |= XFS_TRANS_DIRTY;
set_bit(XFS_LI_DIRTY, &cuip->cui_item.li_flags);
/*
* atomic_inc_return gives us the value after the increment;
* we want to use it as an array index so we need to subtract 1 from
* it.
*/
next_extent = atomic_inc_return(&cuip->cui_next_extent) - 1;
ASSERT(next_extent < cuip->cui_format.cui_nextents);
ext = &cuip->cui_format.cui_extents[next_extent];
ext->pe_startblock = refc->ri_startblock;
ext->pe_len = refc->ri_blockcount;
xfs_trans_set_refcount_flags(ext, refc->ri_type);
}
static struct xfs_log_item *
xfs_refcount_update_create_intent(
struct xfs_trans *tp,
struct list_head *items,
unsigned int count,
bool sort)
{
struct xfs_mount *mp = tp->t_mountp;
struct xfs_cui_log_item *cuip = xfs_cui_init(mp, count);
struct xfs_refcount_intent *refc;
ASSERT(count > 0);
xfs_trans_add_item(tp, &cuip->cui_item);
if (sort)
list_sort(mp, items, xfs_refcount_update_diff_items);
list_for_each_entry(refc, items, ri_list)
xfs_refcount_update_log_item(tp, cuip, refc);
return &cuip->cui_item;
}
/* Get an CUD so we can process all the deferred refcount updates. */
static struct xfs_log_item *
xfs_refcount_update_create_done(
struct xfs_trans *tp,
struct xfs_log_item *intent,
unsigned int count)
{
return &xfs_trans_get_cud(tp, CUI_ITEM(intent))->cud_item;
}
/* Process a deferred refcount update. */
STATIC int
xfs_refcount_update_finish_item(
struct xfs_trans *tp,
struct xfs_log_item *done,
struct list_head *item,
struct xfs_btree_cur **state)
{
struct xfs_refcount_intent *refc;
xfs_fsblock_t new_fsb;
xfs_extlen_t new_aglen;
int error;
refc = container_of(item, struct xfs_refcount_intent, ri_list);
error = xfs_trans_log_finish_refcount_update(tp, CUD_ITEM(done),
refc->ri_type, refc->ri_startblock, refc->ri_blockcount,
&new_fsb, &new_aglen, state);
/* Did we run out of reservation? Requeue what we didn't finish. */
if (!error && new_aglen > 0) {
ASSERT(refc->ri_type == XFS_REFCOUNT_INCREASE ||
refc->ri_type == XFS_REFCOUNT_DECREASE);
refc->ri_startblock = new_fsb;
refc->ri_blockcount = new_aglen;
return -EAGAIN;
}
kmem_cache_free(xfs_refcount_intent_cache, refc);
return error;
}
/* Abort all pending CUIs. */
STATIC void
xfs_refcount_update_abort_intent(
struct xfs_log_item *intent)
{
xfs_cui_release(CUI_ITEM(intent));
}
/* Cancel a deferred refcount update. */
STATIC void
xfs_refcount_update_cancel_item(
struct list_head *item)
{
struct xfs_refcount_intent *refc;
refc = container_of(item, struct xfs_refcount_intent, ri_list);
kmem_cache_free(xfs_refcount_intent_cache, refc);
}
const struct xfs_defer_op_type xfs_refcount_update_defer_type = {
.max_items = XFS_CUI_MAX_FAST_EXTENTS,
.create_intent = xfs_refcount_update_create_intent,
.abort_intent = xfs_refcount_update_abort_intent,
.create_done = xfs_refcount_update_create_done,
.finish_item = xfs_refcount_update_finish_item,
.finish_cleanup = xfs_refcount_finish_one_cleanup,
.cancel_item = xfs_refcount_update_cancel_item,
};
/* Is this recovered CUI ok? */
static inline bool
xfs_cui_validate_phys(
struct xfs_mount *mp,
struct xfs_phys_extent *refc)
{
if (!xfs_has_reflink(mp))
return false;
if (refc->pe_flags & ~XFS_REFCOUNT_EXTENT_FLAGS)
return false;
switch (refc->pe_flags & XFS_REFCOUNT_EXTENT_TYPE_MASK) {
case XFS_REFCOUNT_INCREASE:
case XFS_REFCOUNT_DECREASE:
case XFS_REFCOUNT_ALLOC_COW:
case XFS_REFCOUNT_FREE_COW:
break;
default:
return false;
}
return xfs_verify_fsbext(mp, refc->pe_startblock, refc->pe_len);
}
/*
* Process a refcount update intent item that was recovered from the log.
* We need to update the refcountbt.
*/
STATIC int
xfs_cui_item_recover(
struct xfs_log_item *lip,
xfs: proper replay of deferred ops queued during log recovery When we replay unfinished intent items that have been recovered from the log, it's possible that the replay will cause the creation of more deferred work items. As outlined in commit 509955823cc9c ("xfs: log recovery should replay deferred ops in order"), later work items have an implicit ordering dependency on earlier work items. Therefore, recovery must replay the items (both recovered and created) in the same order that they would have been during normal operation. For log recovery, we enforce this ordering by using an empty transaction to collect deferred ops that get created in the process of recovering a log intent item to prevent them from being committed before the rest of the recovered intent items. After we finish committing all the recovered log items, we allocate a transaction with an enormous block reservation, splice our huge list of created deferred ops into that transaction, and commit it, thereby finishing all those ops. This is /really/ hokey -- it's the one place in XFS where we allow nested transactions; the splicing of the defer ops list is is inelegant and has to be done twice per recovery function; and the broken way we handle inode pointers and block reservations cause subtle use-after-free and allocator problems that will be fixed by this patch and the two patches after it. Therefore, replace the hokey empty transaction with a structure designed to capture each chain of deferred ops that are created as part of recovering a single unfinished log intent. Finally, refactor the loop that replays those chains to do so using one transaction per chain. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-09-26 08:39:37 +08:00
struct list_head *capture_list)
{
struct xfs_bmbt_irec irec;
struct xfs_cui_log_item *cuip = CUI_ITEM(lip);
struct xfs_phys_extent *refc;
struct xfs_cud_log_item *cudp;
struct xfs_trans *tp;
struct xfs_btree_cur *rcur = NULL;
struct xfs_mount *mp = lip->li_log->l_mp;
xfs_fsblock_t new_fsb;
xfs_extlen_t new_len;
unsigned int refc_type;
bool requeue_only = false;
enum xfs_refcount_intent_type type;
int i;
int error = 0;
/*
* First check the validity of the extents described by the
* CUI. If any are bad, then assume that all are bad and
* just toss the CUI.
*/
for (i = 0; i < cuip->cui_format.cui_nextents; i++) {
if (!xfs_cui_validate_phys(mp,
&cuip->cui_format.cui_extents[i])) {
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
&cuip->cui_format,
sizeof(cuip->cui_format));
return -EFSCORRUPTED;
}
}
/*
* Under normal operation, refcount updates are deferred, so we
* wouldn't be adding them directly to a transaction. All
* refcount updates manage reservation usage internally and
* dynamically by deferring work that won't fit in the
* transaction. Normally, any work that needs to be deferred
* gets attached to the same defer_ops that scheduled the
* refcount update. However, we're in log recovery here, so we
* use the passed in defer_ops and to finish up any work that
* doesn't fit. We need to reserve enough blocks to handle a
* full btree split on either end of the refcount range.
*/
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate,
mp->m_refc_maxlevels * 2, 0, XFS_TRANS_RESERVE, &tp);
if (error)
return error;
xfs: proper replay of deferred ops queued during log recovery When we replay unfinished intent items that have been recovered from the log, it's possible that the replay will cause the creation of more deferred work items. As outlined in commit 509955823cc9c ("xfs: log recovery should replay deferred ops in order"), later work items have an implicit ordering dependency on earlier work items. Therefore, recovery must replay the items (both recovered and created) in the same order that they would have been during normal operation. For log recovery, we enforce this ordering by using an empty transaction to collect deferred ops that get created in the process of recovering a log intent item to prevent them from being committed before the rest of the recovered intent items. After we finish committing all the recovered log items, we allocate a transaction with an enormous block reservation, splice our huge list of created deferred ops into that transaction, and commit it, thereby finishing all those ops. This is /really/ hokey -- it's the one place in XFS where we allow nested transactions; the splicing of the defer ops list is is inelegant and has to be done twice per recovery function; and the broken way we handle inode pointers and block reservations cause subtle use-after-free and allocator problems that will be fixed by this patch and the two patches after it. Therefore, replace the hokey empty transaction with a structure designed to capture each chain of deferred ops that are created as part of recovering a single unfinished log intent. Finally, refactor the loop that replays those chains to do so using one transaction per chain. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-09-26 08:39:37 +08:00
cudp = xfs_trans_get_cud(tp, cuip);
for (i = 0; i < cuip->cui_format.cui_nextents; i++) {
refc = &cuip->cui_format.cui_extents[i];
refc_type = refc->pe_flags & XFS_REFCOUNT_EXTENT_TYPE_MASK;
switch (refc_type) {
case XFS_REFCOUNT_INCREASE:
case XFS_REFCOUNT_DECREASE:
case XFS_REFCOUNT_ALLOC_COW:
case XFS_REFCOUNT_FREE_COW:
type = refc_type;
break;
default:
XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
error = -EFSCORRUPTED;
goto abort_error;
}
if (requeue_only) {
new_fsb = refc->pe_startblock;
new_len = refc->pe_len;
} else
error = xfs_trans_log_finish_refcount_update(tp, cudp,
type, refc->pe_startblock, refc->pe_len,
&new_fsb, &new_len, &rcur);
if (error == -EFSCORRUPTED)
XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp,
refc, sizeof(*refc));
if (error)
goto abort_error;
/* Requeue what we didn't finish. */
if (new_len > 0) {
irec.br_startblock = new_fsb;
irec.br_blockcount = new_len;
switch (type) {
case XFS_REFCOUNT_INCREASE:
xfs_refcount_increase_extent(tp, &irec);
break;
case XFS_REFCOUNT_DECREASE:
xfs_refcount_decrease_extent(tp, &irec);
break;
case XFS_REFCOUNT_ALLOC_COW:
xfs_refcount_alloc_cow_extent(tp,
irec.br_startblock,
irec.br_blockcount);
break;
case XFS_REFCOUNT_FREE_COW:
xfs_refcount_free_cow_extent(tp,
irec.br_startblock,
irec.br_blockcount);
break;
default:
ASSERT(0);
}
requeue_only = true;
}
}
xfs_refcount_finish_one_cleanup(tp, rcur, error);
return xfs_defer_ops_capture_and_commit(tp, capture_list);
abort_error:
xfs_refcount_finish_one_cleanup(tp, rcur, error);
xfs_trans_cancel(tp);
return error;
}
STATIC bool
xfs_cui_item_match(
struct xfs_log_item *lip,
uint64_t intent_id)
{
return CUI_ITEM(lip)->cui_format.cui_id == intent_id;
}
xfs: periodically relog deferred intent items There's a subtle design flaw in the deferred log item code that can lead to pinning the log tail. Taking up the defer ops chain examples from the previous commit, we can get trapped in sequences like this: Caller hands us a transaction t0 with D0-D3 attached. The defer ops chain will look like the following if the transaction rolls succeed: t1: D0(t0), D1(t0), D2(t0), D3(t0) t2: d4(t1), d5(t1), D1(t0), D2(t0), D3(t0) t3: d5(t1), D1(t0), D2(t0), D3(t0) ... t9: d9(t7), D3(t0) t10: D3(t0) t11: d10(t10), d11(t10) t12: d11(t10) In transaction 9, we finish d9 and try to roll to t10 while holding onto an intent item for D3 that we logged in t0. The previous commit changed the order in which we place new defer ops in the defer ops processing chain to reduce the maximum chain length. Now make xfs_defer_finish_noroll capable of relogging the entire chain periodically so that we can always move the log tail forward. Most chains will never get relogged, except for operations that generate very long chains (large extents containing many blocks with different sharing levels) or are on filesystems with small logs and a lot of ongoing metadata updates. Callers are now required to ensure that the transaction reservation is large enough to handle logging done items and new intent items for the maximum possible chain length. Most callers are careful to keep the chain lengths low, so the overhead should be minimal. The decision to relog an intent item is made based on whether the intent was logged in a previous checkpoint, since there's no point in relogging an intent into the same checkpoint. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2020-09-28 07:18:13 +08:00
/* Relog an intent item to push the log tail forward. */
static struct xfs_log_item *
xfs_cui_item_relog(
struct xfs_log_item *intent,
struct xfs_trans *tp)
{
struct xfs_cud_log_item *cudp;
struct xfs_cui_log_item *cuip;
struct xfs_phys_extent *extp;
unsigned int count;
count = CUI_ITEM(intent)->cui_format.cui_nextents;
extp = CUI_ITEM(intent)->cui_format.cui_extents;
tp->t_flags |= XFS_TRANS_DIRTY;
cudp = xfs_trans_get_cud(tp, CUI_ITEM(intent));
set_bit(XFS_LI_DIRTY, &cudp->cud_item.li_flags);
cuip = xfs_cui_init(tp->t_mountp, count);
memcpy(cuip->cui_format.cui_extents, extp, count * sizeof(*extp));
atomic_set(&cuip->cui_next_extent, count);
xfs_trans_add_item(tp, &cuip->cui_item);
set_bit(XFS_LI_DIRTY, &cuip->cui_item.li_flags);
return &cuip->cui_item;
}
static const struct xfs_item_ops xfs_cui_item_ops = {
.flags = XFS_ITEM_INTENT,
.iop_size = xfs_cui_item_size,
.iop_format = xfs_cui_item_format,
.iop_unpin = xfs_cui_item_unpin,
.iop_release = xfs_cui_item_release,
.iop_recover = xfs_cui_item_recover,
.iop_match = xfs_cui_item_match,
xfs: periodically relog deferred intent items There's a subtle design flaw in the deferred log item code that can lead to pinning the log tail. Taking up the defer ops chain examples from the previous commit, we can get trapped in sequences like this: Caller hands us a transaction t0 with D0-D3 attached. The defer ops chain will look like the following if the transaction rolls succeed: t1: D0(t0), D1(t0), D2(t0), D3(t0) t2: d4(t1), d5(t1), D1(t0), D2(t0), D3(t0) t3: d5(t1), D1(t0), D2(t0), D3(t0) ... t9: d9(t7), D3(t0) t10: D3(t0) t11: d10(t10), d11(t10) t12: d11(t10) In transaction 9, we finish d9 and try to roll to t10 while holding onto an intent item for D3 that we logged in t0. The previous commit changed the order in which we place new defer ops in the defer ops processing chain to reduce the maximum chain length. Now make xfs_defer_finish_noroll capable of relogging the entire chain periodically so that we can always move the log tail forward. Most chains will never get relogged, except for operations that generate very long chains (large extents containing many blocks with different sharing levels) or are on filesystems with small logs and a lot of ongoing metadata updates. Callers are now required to ensure that the transaction reservation is large enough to handle logging done items and new intent items for the maximum possible chain length. Most callers are careful to keep the chain lengths low, so the overhead should be minimal. The decision to relog an intent item is made based on whether the intent was logged in a previous checkpoint, since there's no point in relogging an intent into the same checkpoint. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2020-09-28 07:18:13 +08:00
.iop_relog = xfs_cui_item_relog,
};
/*
* Copy an CUI format buffer from the given buf, and into the destination
* CUI format structure. The CUI/CUD items were designed not to need any
* special alignment handling.
*/
static int
xfs_cui_copy_format(
struct xfs_log_iovec *buf,
struct xfs_cui_log_format *dst_cui_fmt)
{
struct xfs_cui_log_format *src_cui_fmt;
uint len;
src_cui_fmt = buf->i_addr;
len = xfs_cui_log_format_sizeof(src_cui_fmt->cui_nextents);
if (buf->i_len == len) {
memcpy(dst_cui_fmt, src_cui_fmt, len);
return 0;
}
XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, NULL);
return -EFSCORRUPTED;
}
/*
* This routine is called to create an in-core extent refcount update
* item from the cui format structure which was logged on disk.
* It allocates an in-core cui, copies the extents from the format
* structure into it, and adds the cui to the AIL with the given
* LSN.
*/
STATIC int
xlog_recover_cui_commit_pass2(
struct xlog *log,
struct list_head *buffer_list,
struct xlog_recover_item *item,
xfs_lsn_t lsn)
{
int error;
struct xfs_mount *mp = log->l_mp;
struct xfs_cui_log_item *cuip;
struct xfs_cui_log_format *cui_formatp;
cui_formatp = item->ri_buf[0].i_addr;
cuip = xfs_cui_init(mp, cui_formatp->cui_nextents);
error = xfs_cui_copy_format(&item->ri_buf[0], &cuip->cui_format);
if (error) {
xfs_cui_item_free(cuip);
return error;
}
atomic_set(&cuip->cui_next_extent, cui_formatp->cui_nextents);
/*
* Insert the intent into the AIL directly and drop one reference so
* that finishing or canceling the work will drop the other.
*/
xfs_trans_ail_insert(log->l_ailp, &cuip->cui_item, lsn);
xfs_cui_release(cuip);
return 0;
}
const struct xlog_recover_item_ops xlog_cui_item_ops = {
.item_type = XFS_LI_CUI,
.commit_pass2 = xlog_recover_cui_commit_pass2,
};
/*
* This routine is called when an CUD format structure is found in a committed
* transaction in the log. Its purpose is to cancel the corresponding CUI if it
* was still in the log. To do this it searches the AIL for the CUI with an id
* equal to that in the CUD format structure. If we find it we drop the CUD
* reference, which removes the CUI from the AIL and frees it.
*/
STATIC int
xlog_recover_cud_commit_pass2(
struct xlog *log,
struct list_head *buffer_list,
struct xlog_recover_item *item,
xfs_lsn_t lsn)
{
struct xfs_cud_log_format *cud_formatp;
cud_formatp = item->ri_buf[0].i_addr;
if (item->ri_buf[0].i_len != sizeof(struct xfs_cud_log_format)) {
XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
return -EFSCORRUPTED;
}
xlog_recover_release_intent(log, XFS_LI_CUI, cud_formatp->cud_cui_id);
return 0;
}
const struct xlog_recover_item_ops xlog_cud_item_ops = {
.item_type = XFS_LI_CUD,
.commit_pass2 = xlog_recover_cud_commit_pass2,
};