linux/fs/xfs/xfs_rmap_item.c
Darrick J. Wong c4cf1acdb1 xfs: better log intent item refcount checking
Use ASSERTs on the log intent item refcounts so that we fail noisily if
anyone tries to double-free the item.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-04-25 09:40:42 -07:00

532 lines
14 KiB
C

/*
* Copyright (C) 2016 Oracle. All Rights Reserved.
*
* Author: Darrick J. Wong <darrick.wong@oracle.com>
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it would be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.
*/
#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_mount.h"
#include "xfs_defer.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_buf_item.h"
#include "xfs_rmap_item.h"
#include "xfs_log.h"
#include "xfs_rmap.h"
kmem_zone_t *xfs_rui_zone;
kmem_zone_t *xfs_rud_zone;
static inline struct xfs_rui_log_item *RUI_ITEM(struct xfs_log_item *lip)
{
return container_of(lip, struct xfs_rui_log_item, rui_item);
}
void
xfs_rui_item_free(
struct xfs_rui_log_item *ruip)
{
if (ruip->rui_format.rui_nextents > XFS_RUI_MAX_FAST_EXTENTS)
kmem_free(ruip);
else
kmem_zone_free(xfs_rui_zone, ruip);
}
STATIC void
xfs_rui_item_size(
struct xfs_log_item *lip,
int *nvecs,
int *nbytes)
{
struct xfs_rui_log_item *ruip = RUI_ITEM(lip);
*nvecs += 1;
*nbytes += xfs_rui_log_format_sizeof(ruip->rui_format.rui_nextents);
}
/*
* This is called to fill in the vector of log iovecs for the
* given rui log item. We use only 1 iovec, and we point that
* at the rui_log_format structure embedded in the rui item.
* It is at this point that we assert that all of the extent
* slots in the rui item have been filled.
*/
STATIC void
xfs_rui_item_format(
struct xfs_log_item *lip,
struct xfs_log_vec *lv)
{
struct xfs_rui_log_item *ruip = RUI_ITEM(lip);
struct xfs_log_iovec *vecp = NULL;
ASSERT(atomic_read(&ruip->rui_next_extent) ==
ruip->rui_format.rui_nextents);
ruip->rui_format.rui_type = XFS_LI_RUI;
ruip->rui_format.rui_size = 1;
xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_RUI_FORMAT, &ruip->rui_format,
xfs_rui_log_format_sizeof(ruip->rui_format.rui_nextents));
}
/*
* Pinning has no meaning for an rui item, so just return.
*/
STATIC void
xfs_rui_item_pin(
struct xfs_log_item *lip)
{
}
/*
* The unpin operation is the last place an RUI 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 RUI transaction has been successfully committed to make it
* this far. Therefore, we expect whoever committed the RUI to either construct
* and commit the RUD or drop the RUD's reference in the event of error. Simply
* drop the log's RUI reference now that the log is done with it.
*/
STATIC void
xfs_rui_item_unpin(
struct xfs_log_item *lip,
int remove)
{
struct xfs_rui_log_item *ruip = RUI_ITEM(lip);
xfs_rui_release(ruip);
}
/*
* RUI items have no locking or pushing. However, since RUIs are pulled from
* the AIL when their corresponding RUDs are committed to disk, their situation
* is very similar to being pinned. Return XFS_ITEM_PINNED so that the caller
* will eventually flush the log. This should help in getting the RUI out of
* the AIL.
*/
STATIC uint
xfs_rui_item_push(
struct xfs_log_item *lip,
struct list_head *buffer_list)
{
return XFS_ITEM_PINNED;
}
/*
* The RUI has been either committed or aborted if the transaction has been
* cancelled. If the transaction was cancelled, an RUD isn't going to be
* constructed and thus we free the RUI here directly.
*/
STATIC void
xfs_rui_item_unlock(
struct xfs_log_item *lip)
{
if (lip->li_flags & XFS_LI_ABORTED)
xfs_rui_item_free(RUI_ITEM(lip));
}
/*
* The RUI is logged only once and cannot be moved in the log, so simply return
* the lsn at which it's been logged.
*/
STATIC xfs_lsn_t
xfs_rui_item_committed(
struct xfs_log_item *lip,
xfs_lsn_t lsn)
{
return lsn;
}
/*
* The RUI dependency tracking op doesn't do squat. It can't because
* it doesn't know where the free extent is coming from. The dependency
* tracking has to be handled by the "enclosing" metadata object. For
* example, for inodes, the inode is locked throughout the extent freeing
* so the dependency should be recorded there.
*/
STATIC void
xfs_rui_item_committing(
struct xfs_log_item *lip,
xfs_lsn_t lsn)
{
}
/*
* This is the ops vector shared by all rui log items.
*/
static const struct xfs_item_ops xfs_rui_item_ops = {
.iop_size = xfs_rui_item_size,
.iop_format = xfs_rui_item_format,
.iop_pin = xfs_rui_item_pin,
.iop_unpin = xfs_rui_item_unpin,
.iop_unlock = xfs_rui_item_unlock,
.iop_committed = xfs_rui_item_committed,
.iop_push = xfs_rui_item_push,
.iop_committing = xfs_rui_item_committing,
};
/*
* Allocate and initialize an rui item with the given number of extents.
*/
struct xfs_rui_log_item *
xfs_rui_init(
struct xfs_mount *mp,
uint nextents)
{
struct xfs_rui_log_item *ruip;
ASSERT(nextents > 0);
if (nextents > XFS_RUI_MAX_FAST_EXTENTS)
ruip = kmem_zalloc(xfs_rui_log_item_sizeof(nextents), KM_SLEEP);
else
ruip = kmem_zone_zalloc(xfs_rui_zone, KM_SLEEP);
xfs_log_item_init(mp, &ruip->rui_item, XFS_LI_RUI, &xfs_rui_item_ops);
ruip->rui_format.rui_nextents = nextents;
ruip->rui_format.rui_id = (uintptr_t)(void *)ruip;
atomic_set(&ruip->rui_next_extent, 0);
atomic_set(&ruip->rui_refcount, 2);
return ruip;
}
/*
* Copy an RUI format buffer from the given buf, and into the destination
* RUI format structure. The RUI/RUD items were designed not to need any
* special alignment handling.
*/
int
xfs_rui_copy_format(
struct xfs_log_iovec *buf,
struct xfs_rui_log_format *dst_rui_fmt)
{
struct xfs_rui_log_format *src_rui_fmt;
uint len;
src_rui_fmt = buf->i_addr;
len = xfs_rui_log_format_sizeof(src_rui_fmt->rui_nextents);
if (buf->i_len != len)
return -EFSCORRUPTED;
memcpy(dst_rui_fmt, src_rui_fmt, len);
return 0;
}
/*
* Freeing the RUI requires that we remove it from the AIL if it has already
* been placed there. However, the RUI may not yet have been placed in the AIL
* when called by xfs_rui_release() from RUD 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 RUI.
*/
void
xfs_rui_release(
struct xfs_rui_log_item *ruip)
{
ASSERT(atomic_read(&ruip->rui_refcount) > 0);
if (atomic_dec_and_test(&ruip->rui_refcount)) {
xfs_trans_ail_remove(&ruip->rui_item, SHUTDOWN_LOG_IO_ERROR);
xfs_rui_item_free(ruip);
}
}
static inline struct xfs_rud_log_item *RUD_ITEM(struct xfs_log_item *lip)
{
return container_of(lip, struct xfs_rud_log_item, rud_item);
}
STATIC void
xfs_rud_item_size(
struct xfs_log_item *lip,
int *nvecs,
int *nbytes)
{
*nvecs += 1;
*nbytes += sizeof(struct xfs_rud_log_format);
}
/*
* This is called to fill in the vector of log iovecs for the
* given rud log item. We use only 1 iovec, and we point that
* at the rud_log_format structure embedded in the rud item.
* It is at this point that we assert that all of the extent
* slots in the rud item have been filled.
*/
STATIC void
xfs_rud_item_format(
struct xfs_log_item *lip,
struct xfs_log_vec *lv)
{
struct xfs_rud_log_item *rudp = RUD_ITEM(lip);
struct xfs_log_iovec *vecp = NULL;
rudp->rud_format.rud_type = XFS_LI_RUD;
rudp->rud_format.rud_size = 1;
xlog_copy_iovec(lv, &vecp, XLOG_REG_TYPE_RUD_FORMAT, &rudp->rud_format,
sizeof(struct xfs_rud_log_format));
}
/*
* Pinning has no meaning for an rud item, so just return.
*/
STATIC void
xfs_rud_item_pin(
struct xfs_log_item *lip)
{
}
/*
* Since pinning has no meaning for an rud item, unpinning does
* not either.
*/
STATIC void
xfs_rud_item_unpin(
struct xfs_log_item *lip,
int remove)
{
}
/*
* There isn't much you can do to push on an rud item. It is simply stuck
* waiting for the log to be flushed to disk.
*/
STATIC uint
xfs_rud_item_push(
struct xfs_log_item *lip,
struct list_head *buffer_list)
{
return XFS_ITEM_PINNED;
}
/*
* The RUD is either committed or aborted if the transaction is cancelled. If
* the transaction is cancelled, drop our reference to the RUI and free the
* RUD.
*/
STATIC void
xfs_rud_item_unlock(
struct xfs_log_item *lip)
{
struct xfs_rud_log_item *rudp = RUD_ITEM(lip);
if (lip->li_flags & XFS_LI_ABORTED) {
xfs_rui_release(rudp->rud_ruip);
kmem_zone_free(xfs_rud_zone, rudp);
}
}
/*
* When the rud item is committed to disk, all we need to do is delete our
* reference to our partner rui item and then free ourselves. Since we're
* freeing ourselves we must return -1 to keep the transaction code from
* further referencing this item.
*/
STATIC xfs_lsn_t
xfs_rud_item_committed(
struct xfs_log_item *lip,
xfs_lsn_t lsn)
{
struct xfs_rud_log_item *rudp = RUD_ITEM(lip);
/*
* Drop the RUI reference regardless of whether the RUD has been
* aborted. Once the RUD transaction is constructed, it is the sole
* responsibility of the RUD to release the RUI (even if the RUI is
* aborted due to log I/O error).
*/
xfs_rui_release(rudp->rud_ruip);
kmem_zone_free(xfs_rud_zone, rudp);
return (xfs_lsn_t)-1;
}
/*
* The RUD dependency tracking op doesn't do squat. It can't because
* it doesn't know where the free extent is coming from. The dependency
* tracking has to be handled by the "enclosing" metadata object. For
* example, for inodes, the inode is locked throughout the extent freeing
* so the dependency should be recorded there.
*/
STATIC void
xfs_rud_item_committing(
struct xfs_log_item *lip,
xfs_lsn_t lsn)
{
}
/*
* This is the ops vector shared by all rud log items.
*/
static const struct xfs_item_ops xfs_rud_item_ops = {
.iop_size = xfs_rud_item_size,
.iop_format = xfs_rud_item_format,
.iop_pin = xfs_rud_item_pin,
.iop_unpin = xfs_rud_item_unpin,
.iop_unlock = xfs_rud_item_unlock,
.iop_committed = xfs_rud_item_committed,
.iop_push = xfs_rud_item_push,
.iop_committing = xfs_rud_item_committing,
};
/*
* Allocate and initialize an rud item with the given number of extents.
*/
struct xfs_rud_log_item *
xfs_rud_init(
struct xfs_mount *mp,
struct xfs_rui_log_item *ruip)
{
struct xfs_rud_log_item *rudp;
rudp = kmem_zone_zalloc(xfs_rud_zone, KM_SLEEP);
xfs_log_item_init(mp, &rudp->rud_item, XFS_LI_RUD, &xfs_rud_item_ops);
rudp->rud_ruip = ruip;
rudp->rud_format.rud_rui_id = ruip->rui_format.rui_id;
return rudp;
}
/*
* Process an rmap update intent item that was recovered from the log.
* We need to update the rmapbt.
*/
int
xfs_rui_recover(
struct xfs_mount *mp,
struct xfs_rui_log_item *ruip)
{
int i;
int error = 0;
struct xfs_map_extent *rmap;
xfs_fsblock_t startblock_fsb;
bool op_ok;
struct xfs_rud_log_item *rudp;
enum xfs_rmap_intent_type type;
int whichfork;
xfs_exntst_t state;
struct xfs_trans *tp;
struct xfs_btree_cur *rcur = NULL;
ASSERT(!test_bit(XFS_RUI_RECOVERED, &ruip->rui_flags));
/*
* First check the validity of the extents described by the
* RUI. If any are bad, then assume that all are bad and
* just toss the RUI.
*/
for (i = 0; i < ruip->rui_format.rui_nextents; i++) {
rmap = &ruip->rui_format.rui_extents[i];
startblock_fsb = XFS_BB_TO_FSB(mp,
XFS_FSB_TO_DADDR(mp, rmap->me_startblock));
switch (rmap->me_flags & XFS_RMAP_EXTENT_TYPE_MASK) {
case XFS_RMAP_EXTENT_MAP:
case XFS_RMAP_EXTENT_MAP_SHARED:
case XFS_RMAP_EXTENT_UNMAP:
case XFS_RMAP_EXTENT_UNMAP_SHARED:
case XFS_RMAP_EXTENT_CONVERT:
case XFS_RMAP_EXTENT_CONVERT_SHARED:
case XFS_RMAP_EXTENT_ALLOC:
case XFS_RMAP_EXTENT_FREE:
op_ok = true;
break;
default:
op_ok = false;
break;
}
if (!op_ok || startblock_fsb == 0 ||
rmap->me_len == 0 ||
startblock_fsb >= mp->m_sb.sb_dblocks ||
rmap->me_len >= mp->m_sb.sb_agblocks ||
(rmap->me_flags & ~XFS_RMAP_EXTENT_FLAGS)) {
/*
* This will pull the RUI from the AIL and
* free the memory associated with it.
*/
set_bit(XFS_RUI_RECOVERED, &ruip->rui_flags);
xfs_rui_release(ruip);
return -EIO;
}
}
error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
if (error)
return error;
rudp = xfs_trans_get_rud(tp, ruip);
for (i = 0; i < ruip->rui_format.rui_nextents; i++) {
rmap = &ruip->rui_format.rui_extents[i];
state = (rmap->me_flags & XFS_RMAP_EXTENT_UNWRITTEN) ?
XFS_EXT_UNWRITTEN : XFS_EXT_NORM;
whichfork = (rmap->me_flags & XFS_RMAP_EXTENT_ATTR_FORK) ?
XFS_ATTR_FORK : XFS_DATA_FORK;
switch (rmap->me_flags & XFS_RMAP_EXTENT_TYPE_MASK) {
case XFS_RMAP_EXTENT_MAP:
type = XFS_RMAP_MAP;
break;
case XFS_RMAP_EXTENT_MAP_SHARED:
type = XFS_RMAP_MAP_SHARED;
break;
case XFS_RMAP_EXTENT_UNMAP:
type = XFS_RMAP_UNMAP;
break;
case XFS_RMAP_EXTENT_UNMAP_SHARED:
type = XFS_RMAP_UNMAP_SHARED;
break;
case XFS_RMAP_EXTENT_CONVERT:
type = XFS_RMAP_CONVERT;
break;
case XFS_RMAP_EXTENT_CONVERT_SHARED:
type = XFS_RMAP_CONVERT_SHARED;
break;
case XFS_RMAP_EXTENT_ALLOC:
type = XFS_RMAP_ALLOC;
break;
case XFS_RMAP_EXTENT_FREE:
type = XFS_RMAP_FREE;
break;
default:
error = -EFSCORRUPTED;
goto abort_error;
}
error = xfs_trans_log_finish_rmap_update(tp, rudp, type,
rmap->me_owner, whichfork,
rmap->me_startoff, rmap->me_startblock,
rmap->me_len, state, &rcur);
if (error)
goto abort_error;
}
xfs_rmap_finish_one_cleanup(tp, rcur, error);
set_bit(XFS_RUI_RECOVERED, &ruip->rui_flags);
error = xfs_trans_commit(tp);
return error;
abort_error:
xfs_rmap_finish_one_cleanup(tp, rcur, error);
xfs_trans_cancel(tp);
return error;
}