Re: [PATCH v22 09/16] xfs: Implement attr logging and replay

Allison Henderson
2021-07-28T09:05:14Z

On 7/27/21 5:39 PM, Darrick J. Wong wrote:
> On Mon, Jul 26, 2021 at 11:20:46PM -0700, Allison Henderson wrote:
>> This patch adds the needed routines to create, log and recover logged
>> extended attribute intents.
>>
>> Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
>> ---
>> fs/xfs/libxfs/xfs_defer.c | 1 +
>> fs/xfs/libxfs/xfs_defer.h | 1 +
>> fs/xfs/libxfs/xfs_format.h | 10 +-
>> fs/xfs/xfs_attr_item.c | 377 +++++++++++++++++++++++++++++++++++++++++++++
>> 4 files changed, 388 insertions(+), 1 deletion(-)
>>
>> diff --git a/fs/xfs/libxfs/xfs_defer.c b/fs/xfs/libxfs/xfs_defer.c
>> index eff4a12..e9caff7 100644
>> --- a/fs/xfs/libxfs/xfs_defer.c
>> +++ b/fs/xfs/libxfs/xfs_defer.c
>> @@ -178,6 +178,7 @@ static const struct xfs_defer_op_type *defer_op_types[] = {
>> [XFS_DEFER_OPS_TYPE_RMAP] = &xfs_rmap_update_defer_type,
>> [XFS_DEFER_OPS_TYPE_FREE] = &xfs_extent_free_defer_type,
>> [XFS_DEFER_OPS_TYPE_AGFL_FREE] = &xfs_agfl_free_defer_type,
>> + [XFS_DEFER_OPS_TYPE_ATTR] = &xfs_attr_defer_type,
>> };
>>
>> static void
>> diff --git a/fs/xfs/libxfs/xfs_defer.h b/fs/xfs/libxfs/xfs_defer.h
>> index 0ed9dfa..72a5789 100644
>> --- a/fs/xfs/libxfs/xfs_defer.h
>> +++ b/fs/xfs/libxfs/xfs_defer.h
>> @@ -19,6 +19,7 @@ enum xfs_defer_ops_type {
>> XFS_DEFER_OPS_TYPE_RMAP,
>> XFS_DEFER_OPS_TYPE_FREE,
>> XFS_DEFER_OPS_TYPE_AGFL_FREE,
>> + XFS_DEFER_OPS_TYPE_ATTR,
>> XFS_DEFER_OPS_TYPE_MAX,
>> };
>>
>> diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
>> index 3a4da111..93c1263 100644
>> --- a/fs/xfs/libxfs/xfs_format.h
>> +++ b/fs/xfs/libxfs/xfs_format.h
>> @@ -485,7 +485,9 @@ xfs_sb_has_incompat_feature(
>> return (sbp->sb_features_incompat & feature) != 0;
>> }
>>
>> -#define XFS_SB_FEAT_INCOMPAT_LOG_ALL 0
>> +#define XFS_SB_FEAT_INCOMPAT_LOG_DELATTR (1 << 0) /* Delayed Attributes */
>
> Echoing the conversation going on in IRC, can we change the name of this
> feature bit/flag/function? What we're really describing here is using
> log-intent-based extended attribute updates.
>
> IOWS, how about XFS_SB_FEAT_INCOMPAT_LOG_XATTRS?
Sure, that's fine.

>
>> +#define XFS_SB_FEAT_INCOMPAT_LOG_ALL \
>> + (XFS_SB_FEAT_INCOMPAT_LOG_DELATTR)
>> #define XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN ~XFS_SB_FEAT_INCOMPAT_LOG_ALL
>> static inline bool
>> xfs_sb_has_incompat_log_feature(
>> @@ -590,6 +592,12 @@ static inline bool xfs_sb_version_hasbigtime(struct xfs_sb *sbp)
>> (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_BIGTIME);
>> }
>>
>> +static inline bool xfs_sb_version_hasdelattr(struct xfs_sb *sbp)
>
> sb_version_haslogxattrs?
Ok, will update

>
>> +{
>> + return XFS_SB_VERSION_NUM(sbp) == XFS_SB_VERSION_5 &&
>> + (sbp->sb_features_incompat & XFS_SB_FEAT_INCOMPAT_LOG_DELATTR);
>
> sb_features_log_incompat, as Chandan pointed out.
Yep, will fix

>
>> +}
>> +
>> /*
>> * Inode btree block counter. We record the number of inobt and finobt blocks
>> * in the AGI header so that we can skip the finobt walk at mount time when
>> diff --git a/fs/xfs/xfs_attr_item.c b/fs/xfs/xfs_attr_item.c
>> index a810c2a..44c44d9 100644
>> --- a/fs/xfs/xfs_attr_item.c
>> +++ b/fs/xfs/xfs_attr_item.c
>> @@ -275,6 +275,182 @@ xfs_attrd_item_release(
>> xfs_attrd_item_free(attrdp);
>> }
>>
>> +/*
>> + * Performs one step of an attribute update intent and marks the attrd item
>> + * dirty.. An attr operation may be a set or a remove. Note that the
>> + * transaction is marked dirty regardless of whether the operation succeeds or
>> + * fails to support the ATTRI/ATTRD lifecycle rules.
>> + */
>> +STATIC int
>> +xfs_trans_attr_finish_update(
>> + struct xfs_delattr_context *dac,
>> + struct xfs_attrd_log_item *attrdp,
>> + struct xfs_buf **leaf_bp,
>> + uint32_t op_flags)
>> +{
>> + struct xfs_da_args *args = dac->da_args;
>> + unsigned int op = op_flags &
>> + XFS_ATTR_OP_FLAGS_TYPE_MASK;
>> + int error;
>> +
>> + error = xfs_qm_dqattach_locked(args->dp, 0);
>> + if (error)
>> + return error;
>
> We already attached dquots in xlog_recover_iget, so you can remove this
> entirely.
I see, ok then, will clean out

>
>> +
>> + switch (op) {
>> + case XFS_ATTR_OP_FLAGS_SET:
>> + args->op_flags |= XFS_DA_OP_ADDNAME;
>> + error = xfs_attr_set_iter(dac, leaf_bp);
>> + break;
>> + case XFS_ATTR_OP_FLAGS_REMOVE:
>> + ASSERT(XFS_IFORK_Q(args->dp));
>> + error = xfs_attr_remove_iter(dac);
>> + break;
>> + default:
>> + error = -EFSCORRUPTED;
>> + break;
>> + }
>> +
>> + /*
>> + * Mark the transaction dirty, even on error. This ensures the
>> + * transaction is aborted, which:
>> + *
>> + * 1.) releases the ATTRI and frees the ATTRD
>> + * 2.) shuts down the filesystem
>> + */
>> + args->trans->t_flags |= XFS_TRANS_DIRTY;
>> +
>> + /*
>> + * attr intent/done items are null when delayed attributes are disabled
>> + */
>> + if (attrdp)
>> + set_bit(XFS_LI_DIRTY, &attrdp->attrd_item.li_flags);
>> +
>> + return error;
>> +}
>> +
>> +/* Log an attr to the intent item. */
>> +STATIC void
>> +xfs_attr_log_item(
>> + struct xfs_trans *tp,
>> + struct xfs_attri_log_item *attrip,
>> + struct xfs_attr_item *attr)
>> +{
>> + struct xfs_attri_log_format *attrp;
>> +
>> + tp->t_flags |= XFS_TRANS_DIRTY;
>> + set_bit(XFS_LI_DIRTY, &attrip->attri_item.li_flags);
>> +
>> + /*
>> + * At this point the xfs_attr_item has been constructed, and we've
>> + * created the log intent. Fill in the attri log item and log format
>> + * structure with fields from this xfs_attr_item
>> + */
>> + attrp = &attrip->attri_format;
>> + attrp->alfi_ino = attr->xattri_dac.da_args->dp->i_ino;
>> + attrp->alfi_op_flags = attr->xattri_op_flags;
>> + attrp->alfi_value_len = attr->xattri_dac.da_args->valuelen;
>> + attrp->alfi_name_len = attr->xattri_dac.da_args->namelen;
>> + attrp->alfi_attr_flags = attr->xattri_dac.da_args->attr_filter;
>> +
>> + attrip->attri_name = (void *)attr->xattri_dac.da_args->name;
>> + attrip->attri_value = attr->xattri_dac.da_args->value;
>> + attrip->attri_name_len = attr->xattri_dac.da_args->namelen;
>> + attrip->attri_value_len = attr->xattri_dac.da_args->valuelen;
>> +}
>> +
>> +/* Get an ATTRI. */
>> +static struct xfs_log_item *
>> +xfs_attr_create_intent(
>> + struct xfs_trans *tp,
>> + struct list_head *items,
>> + unsigned int count,
>> + bool sort)
>> +{
>> + struct xfs_mount *mp = tp->t_mountp;
>> + struct xfs_attri_log_item *attrip;
>> + struct xfs_attr_item *attr;
>> +
>> + ASSERT(count == 1);
>> +
>> + if (!xfs_hasdelattr(mp))
>
> At this point we should already have turned on the log incompat feature
> bit if the sysadmin used the secret mount option, correct? In that
> case, I think this check should be
>
> if (!xfs_sb_version_haslogxattrs(&mp->m_sb))
> return NULL;
Sure, that should be fine

>
>> + return NULL;
>> +
>> + attrip = xfs_attri_init(mp, 0);
>> + if (attrip == NULL)
>> + return NULL;
>> +
>> + xfs_trans_add_item(tp, &attrip->attri_item);
>> + list_for_each_entry(attr, items, xattri_list)
>> + xfs_attr_log_item(tp, attrip, attr);
>> + return &attrip->attri_item;
>> +}
>> +
>> +/* Process an attr. */
>> +STATIC int
>> +xfs_attr_finish_item(
>> + struct xfs_trans *tp,
>> + struct xfs_log_item *done,
>> + struct list_head *item,
>> + struct xfs_btree_cur **state)
>> +{
>> + struct xfs_attr_item *attr;
>> + struct xfs_attrd_log_item *done_item = NULL;
>> + int error;
>> + struct xfs_delattr_context *dac;
>> +
>> + attr = container_of(item, struct xfs_attr_item, xattri_list);
>> + dac = &attr->xattri_dac;
>> + if (done)
>> + done_item = ATTRD_ITEM(done);
>> +
>> + /*
>> + * Corner case that can happen during a recovery. Because the first
>> + * iteration of a multi part delay op happens in xfs_attri_item_recover
>> + * to maintain the order of the log replay items. But the new
>> + * transactions do not automatically rejoin during a recovery as they do
>> + * in a standard delay op, so we need to catch this here and rejoin the
>> + * leaf to the new transaction
>> + */
>> + if (attr->xattri_dac.leaf_bp &&
>> + attr->xattri_dac.leaf_bp->b_transp != tp) {
>> + xfs_trans_bjoin(tp, attr->xattri_dac.leaf_bp);
>> + xfs_trans_bhold(tp, attr->xattri_dac.leaf_bp);
>> + }
>
> This is subtle. The attri recovery function makes a direct call to
> xfs_trans_attr_finish_update before doing the capture-and-commit dance.
> When the captured items get replayed (separately) the defer ops
> mechanism calls this function, and that's the point at which we end up
> here needing to join and hold the leaf_bp to the transaction.
>
> Do we have a reference to leaf_bp at this point? When we return from
> xfs_trans_attr_finish_update in xfs_attri_item_recover, the leaf_bp (if
> any) is joined and held to the transaction that is committed in the
> "commit and capture". Following the transaction commit I /think/ it's
> the case that we still have a reference to the leaf_bp?
>
> So we have a reference to the leaf_bp and eventually we need to join it
> to the transaction that's used to continue the recovery. What if the
> capture and commit function detected buffers that are bheld to the
> transaction and recorded them in the capture structure so that
> xlog_finish_defer_ops could do this part for you?
I see, I think what you are describeing should work, I will poke around
in the capture commit routines and see if I can get that to work.

>
>> +
>> + /*
>> + * Always reset trans after EAGAIN cycle
>> + * since the transaction is new
>> + */
>> + dac->da_args->trans = tp;
>> +
>> + error = xfs_trans_attr_finish_update(dac, done_item, &dac->leaf_bp,
>> + attr->xattri_op_flags);
>> + if (error != -EAGAIN)
>> + kmem_free(attr);
>> +
>> + return error;
>> +}
>> +
>> +/* Abort all pending ATTRs. */
>> +STATIC void
>> +xfs_attr_abort_intent(
>> + struct xfs_log_item *intent)
>> +{
>> + xfs_attri_release(ATTRI_ITEM(intent));
>> +}
>> +
>> +/* Cancel an attr */
>> +STATIC void
>> +xfs_attr_cancel_item(
>> + struct list_head *item)
>> +{
>> + struct xfs_attr_item *attr;
>> +
>> + attr = container_of(item, struct xfs_attr_item, xattri_list);
>> + kmem_free(attr);
>> +}
>> +
>> STATIC xfs_lsn_t
>> xfs_attri_item_committed(
>> struct xfs_log_item *lip,
>> @@ -306,6 +482,30 @@ xfs_attri_item_match(
>> return ATTRI_ITEM(lip)->attri_format.alfi_id == intent_id;
>> }
>>
>> +/*
>> + * This routine is called to allocate an "attr free done" log item.
>> + */
>> +static struct xfs_attrd_log_item *
>> +xfs_trans_get_attrd(struct xfs_trans *tp,
>> + struct xfs_attri_log_item *attrip)
>> +{
>> + struct xfs_attrd_log_item *attrdp;
>> + uint size;
>> +
>> + ASSERT(tp != NULL);
>> +
>> + size = sizeof(struct xfs_attrd_log_item);
>> + attrdp = kmem_zalloc(size, 0);
>> +
>> + xfs_log_item_init(tp->t_mountp, &attrdp->attrd_item, XFS_LI_ATTRD,
>> + &xfs_attrd_item_ops);
>> + attrdp->attrd_attrip = attrip;
>> + attrdp->attrd_format.alfd_alf_id = attrip->attri_format.alfi_id;
>> +
>> + xfs_trans_add_item(tp, &attrdp->attrd_item);
>> + return attrdp;
>> +}
>> +
>> static const struct xfs_item_ops xfs_attrd_item_ops = {
>> .flags = XFS_ITEM_RELEASE_WHEN_COMMITTED,
>> .iop_size = xfs_attrd_item_size,
>> @@ -313,6 +513,29 @@ static const struct xfs_item_ops xfs_attrd_item_ops = {
>> .iop_release = xfs_attrd_item_release,
>> };
>>
>> +
>> +/* Get an ATTRD so we can process all the attrs. */
>> +static struct xfs_log_item *
>> +xfs_attr_create_done(
>> + struct xfs_trans *tp,
>> + struct xfs_log_item *intent,
>> + unsigned int count)
>> +{
>> + if (!intent)
>> + return NULL;
>> +
>> + return &xfs_trans_get_attrd(tp, ATTRI_ITEM(intent))->attrd_item;
>> +}
>> +
>> +const struct xfs_defer_op_type xfs_attr_defer_type = {
>> + .max_items = 1,
>> + .create_intent = xfs_attr_create_intent,
>> + .abort_intent = xfs_attr_abort_intent,
>> + .create_done = xfs_attr_create_done,
>> + .finish_item = xfs_attr_finish_item,
>> + .cancel_item = xfs_attr_cancel_item,
>> +};
>> +
>> /* Is this recovered ATTRI ok? */
>> static inline bool
>> xfs_attri_validate(
>> @@ -340,13 +563,167 @@ xfs_attri_validate(
>> return xfs_hasdelattr(mp);
>> }
>>
>> +/*
>> + * Process an attr intent item that was recovered from the log. We need to
>> + * delete the attr that it describes.
>> + */
>> +STATIC int
>> +xfs_attri_item_recover(
>> + struct xfs_log_item *lip,
>> + struct list_head *capture_list)
>> +{
>> + struct xfs_attri_log_item *attrip = ATTRI_ITEM(lip);
>> + struct xfs_attr_item *attr;
>> + struct xfs_mount *mp = lip->li_mountp;
>> + struct xfs_inode *ip;
>> + struct xfs_da_args *args;
>> + struct xfs_trans *tp;
>> + struct xfs_trans_res tres;
>> + struct xfs_attri_log_format *attrp;
>> + int error, ret = 0;
>> + int total;
>> + int local;
>> + struct xfs_attrd_log_item *done_item = NULL;
>> +
>> + /*
>> + * First check the validity of the attr described by the ATTRI. If any
>> + * are bad, then assume that all are bad and just toss the ATTRI.
>> + */
>> + attrp = &attrip->attri_format;
>> + if (!xfs_attri_validate(mp, attrip))
>> + return -EFSCORRUPTED;
>> +
>> + error = xlog_recover_iget(mp, attrp->alfi_ino, &ip);
>> + if (error)
>> + return error;
>> +
>> + attr = kmem_zalloc(sizeof(struct xfs_attr_item) +
>> + sizeof(struct xfs_da_args), KM_NOFS);
>> + args = (struct xfs_da_args *)((char *)attr +
>> + sizeof(struct xfs_attr_item));
>
> args = (struct xfs_da_args *)(attr + 1); ?
Sure, should be fine. Thanks for the reviews!
Allison

>
> --D
>
>> +
>> + attr->xattri_dac.da_args = args;
>> + attr->xattri_op_flags = attrp->alfi_op_flags;
>> +
>> + args->dp = ip;
>> + args->geo = mp->m_attr_geo;
>> + args->op_flags = attrp->alfi_op_flags;
>> + args->whichfork = XFS_ATTR_FORK;
>> + args->name = attrip->attri_name;
>> + args->namelen = attrp->alfi_name_len;
>> + args->hashval = xfs_da_hashname(args->name, args->namelen);
>> + args->attr_filter = attrp->alfi_attr_flags;
>> +
>> + if (attrp->alfi_op_flags == XFS_ATTR_OP_FLAGS_SET) {
>> + args->value = attrip->attri_value;
>> + args->valuelen = attrp->alfi_value_len;
>> + args->total = xfs_attr_calc_size(args, &local);
>> +
>> + tres.tr_logres = M_RES(mp)->tr_attrsetm.tr_logres +
>> + M_RES(mp)->tr_attrsetrt.tr_logres *
>> + args->total;
>> + tres.tr_logcount = XFS_ATTRSET_LOG_COUNT;
>> + tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
>> + total = args->total;
>> + } else {
>> + tres = M_RES(mp)->tr_attrrm;
>> + total = XFS_ATTRRM_SPACE_RES(mp);
>> + }
>> + error = xfs_trans_alloc(mp, &tres, total, 0, XFS_TRANS_RESERVE, &tp);
>> + if (error)
>> + goto out;
>> +
>> + args->trans = tp;
>> + done_item = xfs_trans_get_attrd(tp, attrip);
>> +
>> + xfs_ilock(ip, XFS_ILOCK_EXCL);
>> + xfs_trans_ijoin(tp, ip, 0);
>> +
>> + ret = xfs_trans_attr_finish_update(&attr->xattri_dac, done_item,
>> + &attr->xattri_dac.leaf_bp,
>> + attrp->alfi_op_flags);
>> + if (ret == -EAGAIN) {
>> + /* There's more work to do, so add it to this transaction */
>> + xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_ATTR, &attr->xattri_list);
>> + } else
>> + error = ret;
>> +
>> + if (error) {
>> + xfs_trans_cancel(tp);
>> + goto out_unlock;
>> + }
>> +
>> + error = xfs_defer_ops_capture_and_commit(tp, ip, capture_list);
>> +
>> +out_unlock:
>> + xfs_iunlock(ip, XFS_ILOCK_EXCL);
>> + xfs_irele(ip);
>> +out:
>> + if (ret != -EAGAIN)
>> + kmem_free(attr);
>> + return error;
>> +}
>> +
>> +/* Re-log an intent item to push the log tail forward. */
>> +static struct xfs_log_item *
>> +xfs_attri_item_relog(
>> + struct xfs_log_item *intent,
>> + struct xfs_trans *tp)
>> +{
>> + struct xfs_attrd_log_item *attrdp;
>> + struct xfs_attri_log_item *old_attrip;
>> + struct xfs_attri_log_item *new_attrip;
>> + struct xfs_attri_log_format *new_attrp;
>> + struct xfs_attri_log_format *old_attrp;
>> + int buffer_size;
>> +
>> + old_attrip = ATTRI_ITEM(intent);
>> + old_attrp = &old_attrip->attri_format;
>> + buffer_size = old_attrp->alfi_value_len + old_attrp->alfi_name_len;
>> +
>> + tp->t_flags |= XFS_TRANS_DIRTY;
>> + attrdp = xfs_trans_get_attrd(tp, old_attrip);
>> + set_bit(XFS_LI_DIRTY, &attrdp->attrd_item.li_flags);
>> +
>> + new_attrip = xfs_attri_init(tp->t_mountp, buffer_size);
>> + new_attrp = &new_attrip->attri_format;
>> +
>> + new_attrp->alfi_ino = old_attrp->alfi_ino;
>> + new_attrp->alfi_op_flags = old_attrp->alfi_op_flags;
>> + new_attrp->alfi_value_len = old_attrp->alfi_value_len;
>> + new_attrp->alfi_name_len = old_attrp->alfi_name_len;
>> + new_attrp->alfi_attr_flags = old_attrp->alfi_attr_flags;
>> +
>> + new_attrip->attri_name_len = old_attrip->attri_name_len;
>> + new_attrip->attri_name = ((char *)new_attrip) +
>> + sizeof(struct xfs_attri_log_item);
>> + memcpy(new_attrip->attri_name, old_attrip->attri_name,
>> + new_attrip->attri_name_len);
>> +
>> + new_attrip->attri_value_len = old_attrip->attri_value_len;
>> + if (new_attrip->attri_value_len > 0) {
>> + new_attrip->attri_value = new_attrip->attri_name +
>> + new_attrip->attri_name_len;
>> +
>> + memcpy(new_attrip->attri_value, old_attrip->attri_value,
>> + new_attrip->attri_value_len);
>> + }
>> +
>> + xfs_trans_add_item(tp, &new_attrip->attri_item);
>> + set_bit(XFS_LI_DIRTY, &new_attrip->attri_item.li_flags);
>> +
>> + return &new_attrip->attri_item;
>> +}
>> +
>> static const struct xfs_item_ops xfs_attri_item_ops = {
>> .iop_size = xfs_attri_item_size,
>> .iop_format = xfs_attri_item_format,
>> .iop_unpin = xfs_attri_item_unpin,
>> .iop_committed = xfs_attri_item_committed,
>> .iop_release = xfs_attri_item_release,
>> + .iop_recover = xfs_attri_item_recover,
>> .iop_match = xfs_attri_item_match,
>> + .iop_relog = xfs_attri_item_relog,
>> };
>>
>>
>> --
>> 2.7.4
>>