tmp_suning_uos_patched/fs/xfs/xfs_trans.c
Dave Chinner 8683edb775 xfs: avoid lockdep false positives in xfs_trans_alloc
We've had a few reports of lockdep tripping over memory reclaim
context vs filesystem freeze "deadlocks". They all have looked
to be false positives on analysis, but it seems that they are
being tripped because we take freeze references before we run
a GFP_KERNEL allocation for the struct xfs_trans.

We can avoid this false positive vector just by re-ordering the
operations in xfs_trans_alloc(). That is. we need allocate the
structure before we take the freeze reference and enter the GFP_NOFS
allocation context that follows the xfs_trans around. This prevents
lockdep from seeing the GFP_KERNEL allocation inside the transaction
context, and that prevents it from triggering the freeze level vs
alloc context vs reclaim warnings.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-09-29 13:46:21 +10:00

1114 lines
29 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
* Copyright (C) 2010 Red Hat, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_extent_busy.h"
#include "xfs_quota.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_log.h"
#include "xfs_trace.h"
#include "xfs_error.h"
#include "xfs_defer.h"
kmem_zone_t *xfs_trans_zone;
#if defined(CONFIG_TRACEPOINTS)
static void
xfs_trans_trace_reservations(
struct xfs_mount *mp)
{
struct xfs_trans_res resv;
struct xfs_trans_res *res;
struct xfs_trans_res *end_res;
int i;
res = (struct xfs_trans_res *)M_RES(mp);
end_res = (struct xfs_trans_res *)(M_RES(mp) + 1);
for (i = 0; res < end_res; i++, res++)
trace_xfs_trans_resv_calc(mp, i, res);
xfs_log_get_max_trans_res(mp, &resv);
trace_xfs_trans_resv_calc(mp, -1, &resv);
}
#else
# define xfs_trans_trace_reservations(mp)
#endif
/*
* Initialize the precomputed transaction reservation values
* in the mount structure.
*/
void
xfs_trans_init(
struct xfs_mount *mp)
{
xfs_trans_resv_calc(mp, M_RES(mp));
xfs_trans_trace_reservations(mp);
}
/*
* Free the transaction structure. If there is more clean up
* to do when the structure is freed, add it here.
*/
STATIC void
xfs_trans_free(
struct xfs_trans *tp)
{
xfs_extent_busy_sort(&tp->t_busy);
xfs_extent_busy_clear(tp->t_mountp, &tp->t_busy, false);
trace_xfs_trans_free(tp, _RET_IP_);
atomic_dec(&tp->t_mountp->m_active_trans);
if (!(tp->t_flags & XFS_TRANS_NO_WRITECOUNT))
sb_end_intwrite(tp->t_mountp->m_super);
xfs_trans_free_dqinfo(tp);
kmem_zone_free(xfs_trans_zone, tp);
}
/*
* This is called to create a new transaction which will share the
* permanent log reservation of the given transaction. The remaining
* unused block and rt extent reservations are also inherited. This
* implies that the original transaction is no longer allowed to allocate
* blocks. Locks and log items, however, are no inherited. They must
* be added to the new transaction explicitly.
*/
STATIC struct xfs_trans *
xfs_trans_dup(
struct xfs_trans *tp)
{
struct xfs_trans *ntp;
trace_xfs_trans_dup(tp, _RET_IP_);
ntp = kmem_zone_zalloc(xfs_trans_zone, KM_SLEEP);
/*
* Initialize the new transaction structure.
*/
ntp->t_magic = XFS_TRANS_HEADER_MAGIC;
ntp->t_mountp = tp->t_mountp;
INIT_LIST_HEAD(&ntp->t_items);
INIT_LIST_HEAD(&ntp->t_busy);
INIT_LIST_HEAD(&ntp->t_dfops);
ntp->t_firstblock = NULLFSBLOCK;
ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
ASSERT(tp->t_ticket != NULL);
ntp->t_flags = XFS_TRANS_PERM_LOG_RES |
(tp->t_flags & XFS_TRANS_RESERVE) |
(tp->t_flags & XFS_TRANS_NO_WRITECOUNT);
/* We gave our writer reference to the new transaction */
tp->t_flags |= XFS_TRANS_NO_WRITECOUNT;
ntp->t_ticket = xfs_log_ticket_get(tp->t_ticket);
ASSERT(tp->t_blk_res >= tp->t_blk_res_used);
ntp->t_blk_res = tp->t_blk_res - tp->t_blk_res_used;
tp->t_blk_res = tp->t_blk_res_used;
ntp->t_rtx_res = tp->t_rtx_res - tp->t_rtx_res_used;
tp->t_rtx_res = tp->t_rtx_res_used;
ntp->t_pflags = tp->t_pflags;
/* move deferred ops over to the new tp */
xfs_defer_move(ntp, tp);
xfs_trans_dup_dqinfo(tp, ntp);
atomic_inc(&tp->t_mountp->m_active_trans);
return ntp;
}
/*
* This is called to reserve free disk blocks and log space for the
* given transaction. This must be done before allocating any resources
* within the transaction.
*
* This will return ENOSPC if there are not enough blocks available.
* It will sleep waiting for available log space.
* The only valid value for the flags parameter is XFS_RES_LOG_PERM, which
* is used by long running transactions. If any one of the reservations
* fails then they will all be backed out.
*
* This does not do quota reservations. That typically is done by the
* caller afterwards.
*/
static int
xfs_trans_reserve(
struct xfs_trans *tp,
struct xfs_trans_res *resp,
uint blocks,
uint rtextents)
{
int error = 0;
bool rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
/* Mark this thread as being in a transaction */
current_set_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
/*
* Attempt to reserve the needed disk blocks by decrementing
* the number needed from the number available. This will
* fail if the count would go below zero.
*/
if (blocks > 0) {
error = xfs_mod_fdblocks(tp->t_mountp, -((int64_t)blocks), rsvd);
if (error != 0) {
current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
return -ENOSPC;
}
tp->t_blk_res += blocks;
}
/*
* Reserve the log space needed for this transaction.
*/
if (resp->tr_logres > 0) {
bool permanent = false;
ASSERT(tp->t_log_res == 0 ||
tp->t_log_res == resp->tr_logres);
ASSERT(tp->t_log_count == 0 ||
tp->t_log_count == resp->tr_logcount);
if (resp->tr_logflags & XFS_TRANS_PERM_LOG_RES) {
tp->t_flags |= XFS_TRANS_PERM_LOG_RES;
permanent = true;
} else {
ASSERT(tp->t_ticket == NULL);
ASSERT(!(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
}
if (tp->t_ticket != NULL) {
ASSERT(resp->tr_logflags & XFS_TRANS_PERM_LOG_RES);
error = xfs_log_regrant(tp->t_mountp, tp->t_ticket);
} else {
error = xfs_log_reserve(tp->t_mountp,
resp->tr_logres,
resp->tr_logcount,
&tp->t_ticket, XFS_TRANSACTION,
permanent);
}
if (error)
goto undo_blocks;
tp->t_log_res = resp->tr_logres;
tp->t_log_count = resp->tr_logcount;
}
/*
* Attempt to reserve the needed realtime extents by decrementing
* the number needed from the number available. This will
* fail if the count would go below zero.
*/
if (rtextents > 0) {
error = xfs_mod_frextents(tp->t_mountp, -((int64_t)rtextents));
if (error) {
error = -ENOSPC;
goto undo_log;
}
tp->t_rtx_res += rtextents;
}
return 0;
/*
* Error cases jump to one of these labels to undo any
* reservations which have already been performed.
*/
undo_log:
if (resp->tr_logres > 0) {
xfs_log_done(tp->t_mountp, tp->t_ticket, NULL, false);
tp->t_ticket = NULL;
tp->t_log_res = 0;
tp->t_flags &= ~XFS_TRANS_PERM_LOG_RES;
}
undo_blocks:
if (blocks > 0) {
xfs_mod_fdblocks(tp->t_mountp, (int64_t)blocks, rsvd);
tp->t_blk_res = 0;
}
current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
return error;
}
int
xfs_trans_alloc(
struct xfs_mount *mp,
struct xfs_trans_res *resp,
uint blocks,
uint rtextents,
uint flags,
struct xfs_trans **tpp)
{
struct xfs_trans *tp;
int error;
/*
* Allocate the handle before we do our freeze accounting and setting up
* GFP_NOFS allocation context so that we avoid lockdep false positives
* by doing GFP_KERNEL allocations inside sb_start_intwrite().
*/
tp = kmem_zone_zalloc(xfs_trans_zone,
(flags & XFS_TRANS_NOFS) ? KM_NOFS : KM_SLEEP);
if (!(flags & XFS_TRANS_NO_WRITECOUNT))
sb_start_intwrite(mp->m_super);
/*
* Zero-reservation ("empty") transactions can't modify anything, so
* they're allowed to run while we're frozen.
*/
WARN_ON(resp->tr_logres > 0 &&
mp->m_super->s_writers.frozen == SB_FREEZE_COMPLETE);
atomic_inc(&mp->m_active_trans);
tp->t_magic = XFS_TRANS_HEADER_MAGIC;
tp->t_flags = flags;
tp->t_mountp = mp;
INIT_LIST_HEAD(&tp->t_items);
INIT_LIST_HEAD(&tp->t_busy);
INIT_LIST_HEAD(&tp->t_dfops);
tp->t_firstblock = NULLFSBLOCK;
error = xfs_trans_reserve(tp, resp, blocks, rtextents);
if (error) {
xfs_trans_cancel(tp);
return error;
}
trace_xfs_trans_alloc(tp, _RET_IP_);
*tpp = tp;
return 0;
}
/*
* Create an empty transaction with no reservation. This is a defensive
* mechanism for routines that query metadata without actually modifying
* them -- if the metadata being queried is somehow cross-linked (think a
* btree block pointer that points higher in the tree), we risk deadlock.
* However, blocks grabbed as part of a transaction can be re-grabbed.
* The verifiers will notice the corrupt block and the operation will fail
* back to userspace without deadlocking.
*
* Note the zero-length reservation; this transaction MUST be cancelled
* without any dirty data.
*/
int
xfs_trans_alloc_empty(
struct xfs_mount *mp,
struct xfs_trans **tpp)
{
struct xfs_trans_res resv = {0};
return xfs_trans_alloc(mp, &resv, 0, 0, XFS_TRANS_NO_WRITECOUNT, tpp);
}
/*
* Record the indicated change to the given field for application
* to the file system's superblock when the transaction commits.
* For now, just store the change in the transaction structure.
*
* Mark the transaction structure to indicate that the superblock
* needs to be updated before committing.
*
* Because we may not be keeping track of allocated/free inodes and
* used filesystem blocks in the superblock, we do not mark the
* superblock dirty in this transaction if we modify these fields.
* We still need to update the transaction deltas so that they get
* applied to the incore superblock, but we don't want them to
* cause the superblock to get locked and logged if these are the
* only fields in the superblock that the transaction modifies.
*/
void
xfs_trans_mod_sb(
xfs_trans_t *tp,
uint field,
int64_t delta)
{
uint32_t flags = (XFS_TRANS_DIRTY|XFS_TRANS_SB_DIRTY);
xfs_mount_t *mp = tp->t_mountp;
switch (field) {
case XFS_TRANS_SB_ICOUNT:
tp->t_icount_delta += delta;
if (xfs_sb_version_haslazysbcount(&mp->m_sb))
flags &= ~XFS_TRANS_SB_DIRTY;
break;
case XFS_TRANS_SB_IFREE:
tp->t_ifree_delta += delta;
if (xfs_sb_version_haslazysbcount(&mp->m_sb))
flags &= ~XFS_TRANS_SB_DIRTY;
break;
case XFS_TRANS_SB_FDBLOCKS:
/*
* Track the number of blocks allocated in the transaction.
* Make sure it does not exceed the number reserved. If so,
* shutdown as this can lead to accounting inconsistency.
*/
if (delta < 0) {
tp->t_blk_res_used += (uint)-delta;
if (tp->t_blk_res_used > tp->t_blk_res)
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
}
tp->t_fdblocks_delta += delta;
if (xfs_sb_version_haslazysbcount(&mp->m_sb))
flags &= ~XFS_TRANS_SB_DIRTY;
break;
case XFS_TRANS_SB_RES_FDBLOCKS:
/*
* The allocation has already been applied to the
* in-core superblock's counter. This should only
* be applied to the on-disk superblock.
*/
tp->t_res_fdblocks_delta += delta;
if (xfs_sb_version_haslazysbcount(&mp->m_sb))
flags &= ~XFS_TRANS_SB_DIRTY;
break;
case XFS_TRANS_SB_FREXTENTS:
/*
* Track the number of blocks allocated in the
* transaction. Make sure it does not exceed the
* number reserved.
*/
if (delta < 0) {
tp->t_rtx_res_used += (uint)-delta;
ASSERT(tp->t_rtx_res_used <= tp->t_rtx_res);
}
tp->t_frextents_delta += delta;
break;
case XFS_TRANS_SB_RES_FREXTENTS:
/*
* The allocation has already been applied to the
* in-core superblock's counter. This should only
* be applied to the on-disk superblock.
*/
ASSERT(delta < 0);
tp->t_res_frextents_delta += delta;
break;
case XFS_TRANS_SB_DBLOCKS:
ASSERT(delta > 0);
tp->t_dblocks_delta += delta;
break;
case XFS_TRANS_SB_AGCOUNT:
ASSERT(delta > 0);
tp->t_agcount_delta += delta;
break;
case XFS_TRANS_SB_IMAXPCT:
tp->t_imaxpct_delta += delta;
break;
case XFS_TRANS_SB_REXTSIZE:
tp->t_rextsize_delta += delta;
break;
case XFS_TRANS_SB_RBMBLOCKS:
tp->t_rbmblocks_delta += delta;
break;
case XFS_TRANS_SB_RBLOCKS:
tp->t_rblocks_delta += delta;
break;
case XFS_TRANS_SB_REXTENTS:
tp->t_rextents_delta += delta;
break;
case XFS_TRANS_SB_REXTSLOG:
tp->t_rextslog_delta += delta;
break;
default:
ASSERT(0);
return;
}
tp->t_flags |= flags;
}
/*
* xfs_trans_apply_sb_deltas() is called from the commit code
* to bring the superblock buffer into the current transaction
* and modify it as requested by earlier calls to xfs_trans_mod_sb().
*
* For now we just look at each field allowed to change and change
* it if necessary.
*/
STATIC void
xfs_trans_apply_sb_deltas(
xfs_trans_t *tp)
{
xfs_dsb_t *sbp;
xfs_buf_t *bp;
int whole = 0;
bp = xfs_trans_getsb(tp, tp->t_mountp, 0);
sbp = XFS_BUF_TO_SBP(bp);
/*
* Check that superblock mods match the mods made to AGF counters.
*/
ASSERT((tp->t_fdblocks_delta + tp->t_res_fdblocks_delta) ==
(tp->t_ag_freeblks_delta + tp->t_ag_flist_delta +
tp->t_ag_btree_delta));
/*
* Only update the superblock counters if we are logging them
*/
if (!xfs_sb_version_haslazysbcount(&(tp->t_mountp->m_sb))) {
if (tp->t_icount_delta)
be64_add_cpu(&sbp->sb_icount, tp->t_icount_delta);
if (tp->t_ifree_delta)
be64_add_cpu(&sbp->sb_ifree, tp->t_ifree_delta);
if (tp->t_fdblocks_delta)
be64_add_cpu(&sbp->sb_fdblocks, tp->t_fdblocks_delta);
if (tp->t_res_fdblocks_delta)
be64_add_cpu(&sbp->sb_fdblocks, tp->t_res_fdblocks_delta);
}
if (tp->t_frextents_delta)
be64_add_cpu(&sbp->sb_frextents, tp->t_frextents_delta);
if (tp->t_res_frextents_delta)
be64_add_cpu(&sbp->sb_frextents, tp->t_res_frextents_delta);
if (tp->t_dblocks_delta) {
be64_add_cpu(&sbp->sb_dblocks, tp->t_dblocks_delta);
whole = 1;
}
if (tp->t_agcount_delta) {
be32_add_cpu(&sbp->sb_agcount, tp->t_agcount_delta);
whole = 1;
}
if (tp->t_imaxpct_delta) {
sbp->sb_imax_pct += tp->t_imaxpct_delta;
whole = 1;
}
if (tp->t_rextsize_delta) {
be32_add_cpu(&sbp->sb_rextsize, tp->t_rextsize_delta);
whole = 1;
}
if (tp->t_rbmblocks_delta) {
be32_add_cpu(&sbp->sb_rbmblocks, tp->t_rbmblocks_delta);
whole = 1;
}
if (tp->t_rblocks_delta) {
be64_add_cpu(&sbp->sb_rblocks, tp->t_rblocks_delta);
whole = 1;
}
if (tp->t_rextents_delta) {
be64_add_cpu(&sbp->sb_rextents, tp->t_rextents_delta);
whole = 1;
}
if (tp->t_rextslog_delta) {
sbp->sb_rextslog += tp->t_rextslog_delta;
whole = 1;
}
xfs_trans_buf_set_type(tp, bp, XFS_BLFT_SB_BUF);
if (whole)
/*
* Log the whole thing, the fields are noncontiguous.
*/
xfs_trans_log_buf(tp, bp, 0, sizeof(xfs_dsb_t) - 1);
else
/*
* Since all the modifiable fields are contiguous, we
* can get away with this.
*/
xfs_trans_log_buf(tp, bp, offsetof(xfs_dsb_t, sb_icount),
offsetof(xfs_dsb_t, sb_frextents) +
sizeof(sbp->sb_frextents) - 1);
}
STATIC int
xfs_sb_mod8(
uint8_t *field,
int8_t delta)
{
int8_t counter = *field;
counter += delta;
if (counter < 0) {
ASSERT(0);
return -EINVAL;
}
*field = counter;
return 0;
}
STATIC int
xfs_sb_mod32(
uint32_t *field,
int32_t delta)
{
int32_t counter = *field;
counter += delta;
if (counter < 0) {
ASSERT(0);
return -EINVAL;
}
*field = counter;
return 0;
}
STATIC int
xfs_sb_mod64(
uint64_t *field,
int64_t delta)
{
int64_t counter = *field;
counter += delta;
if (counter < 0) {
ASSERT(0);
return -EINVAL;
}
*field = counter;
return 0;
}
/*
* xfs_trans_unreserve_and_mod_sb() is called to release unused reservations
* and apply superblock counter changes to the in-core superblock. The
* t_res_fdblocks_delta and t_res_frextents_delta fields are explicitly NOT
* applied to the in-core superblock. The idea is that that has already been
* done.
*
* If we are not logging superblock counters, then the inode allocated/free and
* used block counts are not updated in the on disk superblock. In this case,
* XFS_TRANS_SB_DIRTY will not be set when the transaction is updated but we
* still need to update the incore superblock with the changes.
*/
void
xfs_trans_unreserve_and_mod_sb(
struct xfs_trans *tp)
{
struct xfs_mount *mp = tp->t_mountp;
bool rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
int64_t blkdelta = 0;
int64_t rtxdelta = 0;
int64_t idelta = 0;
int64_t ifreedelta = 0;
int error;
/* calculate deltas */
if (tp->t_blk_res > 0)
blkdelta = tp->t_blk_res;
if ((tp->t_fdblocks_delta != 0) &&
(xfs_sb_version_haslazysbcount(&mp->m_sb) ||
(tp->t_flags & XFS_TRANS_SB_DIRTY)))
blkdelta += tp->t_fdblocks_delta;
if (tp->t_rtx_res > 0)
rtxdelta = tp->t_rtx_res;
if ((tp->t_frextents_delta != 0) &&
(tp->t_flags & XFS_TRANS_SB_DIRTY))
rtxdelta += tp->t_frextents_delta;
if (xfs_sb_version_haslazysbcount(&mp->m_sb) ||
(tp->t_flags & XFS_TRANS_SB_DIRTY)) {
idelta = tp->t_icount_delta;
ifreedelta = tp->t_ifree_delta;
}
/* apply the per-cpu counters */
if (blkdelta) {
error = xfs_mod_fdblocks(mp, blkdelta, rsvd);
if (error)
goto out;
}
if (idelta) {
error = xfs_mod_icount(mp, idelta);
if (error)
goto out_undo_fdblocks;
}
if (ifreedelta) {
error = xfs_mod_ifree(mp, ifreedelta);
if (error)
goto out_undo_icount;
}
if (rtxdelta == 0 && !(tp->t_flags & XFS_TRANS_SB_DIRTY))
return;
/* apply remaining deltas */
spin_lock(&mp->m_sb_lock);
if (rtxdelta) {
error = xfs_sb_mod64(&mp->m_sb.sb_frextents, rtxdelta);
if (error)
goto out_undo_ifree;
}
if (tp->t_dblocks_delta != 0) {
error = xfs_sb_mod64(&mp->m_sb.sb_dblocks, tp->t_dblocks_delta);
if (error)
goto out_undo_frextents;
}
if (tp->t_agcount_delta != 0) {
error = xfs_sb_mod32(&mp->m_sb.sb_agcount, tp->t_agcount_delta);
if (error)
goto out_undo_dblocks;
}
if (tp->t_imaxpct_delta != 0) {
error = xfs_sb_mod8(&mp->m_sb.sb_imax_pct, tp->t_imaxpct_delta);
if (error)
goto out_undo_agcount;
}
if (tp->t_rextsize_delta != 0) {
error = xfs_sb_mod32(&mp->m_sb.sb_rextsize,
tp->t_rextsize_delta);
if (error)
goto out_undo_imaxpct;
}
if (tp->t_rbmblocks_delta != 0) {
error = xfs_sb_mod32(&mp->m_sb.sb_rbmblocks,
tp->t_rbmblocks_delta);
if (error)
goto out_undo_rextsize;
}
if (tp->t_rblocks_delta != 0) {
error = xfs_sb_mod64(&mp->m_sb.sb_rblocks, tp->t_rblocks_delta);
if (error)
goto out_undo_rbmblocks;
}
if (tp->t_rextents_delta != 0) {
error = xfs_sb_mod64(&mp->m_sb.sb_rextents,
tp->t_rextents_delta);
if (error)
goto out_undo_rblocks;
}
if (tp->t_rextslog_delta != 0) {
error = xfs_sb_mod8(&mp->m_sb.sb_rextslog,
tp->t_rextslog_delta);
if (error)
goto out_undo_rextents;
}
spin_unlock(&mp->m_sb_lock);
return;
out_undo_rextents:
if (tp->t_rextents_delta)
xfs_sb_mod64(&mp->m_sb.sb_rextents, -tp->t_rextents_delta);
out_undo_rblocks:
if (tp->t_rblocks_delta)
xfs_sb_mod64(&mp->m_sb.sb_rblocks, -tp->t_rblocks_delta);
out_undo_rbmblocks:
if (tp->t_rbmblocks_delta)
xfs_sb_mod32(&mp->m_sb.sb_rbmblocks, -tp->t_rbmblocks_delta);
out_undo_rextsize:
if (tp->t_rextsize_delta)
xfs_sb_mod32(&mp->m_sb.sb_rextsize, -tp->t_rextsize_delta);
out_undo_imaxpct:
if (tp->t_rextsize_delta)
xfs_sb_mod8(&mp->m_sb.sb_imax_pct, -tp->t_imaxpct_delta);
out_undo_agcount:
if (tp->t_agcount_delta)
xfs_sb_mod32(&mp->m_sb.sb_agcount, -tp->t_agcount_delta);
out_undo_dblocks:
if (tp->t_dblocks_delta)
xfs_sb_mod64(&mp->m_sb.sb_dblocks, -tp->t_dblocks_delta);
out_undo_frextents:
if (rtxdelta)
xfs_sb_mod64(&mp->m_sb.sb_frextents, -rtxdelta);
out_undo_ifree:
spin_unlock(&mp->m_sb_lock);
if (ifreedelta)
xfs_mod_ifree(mp, -ifreedelta);
out_undo_icount:
if (idelta)
xfs_mod_icount(mp, -idelta);
out_undo_fdblocks:
if (blkdelta)
xfs_mod_fdblocks(mp, -blkdelta, rsvd);
out:
ASSERT(error == 0);
return;
}
/* Add the given log item to the transaction's list of log items. */
void
xfs_trans_add_item(
struct xfs_trans *tp,
struct xfs_log_item *lip)
{
ASSERT(lip->li_mountp == tp->t_mountp);
ASSERT(lip->li_ailp == tp->t_mountp->m_ail);
ASSERT(list_empty(&lip->li_trans));
ASSERT(!test_bit(XFS_LI_DIRTY, &lip->li_flags));
list_add_tail(&lip->li_trans, &tp->t_items);
trace_xfs_trans_add_item(tp, _RET_IP_);
}
/*
* Unlink the log item from the transaction. the log item is no longer
* considered dirty in this transaction, as the linked transaction has
* finished, either by abort or commit completion.
*/
void
xfs_trans_del_item(
struct xfs_log_item *lip)
{
clear_bit(XFS_LI_DIRTY, &lip->li_flags);
list_del_init(&lip->li_trans);
}
/* Detach and unlock all of the items in a transaction */
void
xfs_trans_free_items(
struct xfs_trans *tp,
xfs_lsn_t commit_lsn,
bool abort)
{
struct xfs_log_item *lip, *next;
trace_xfs_trans_free_items(tp, _RET_IP_);
list_for_each_entry_safe(lip, next, &tp->t_items, li_trans) {
xfs_trans_del_item(lip);
if (commit_lsn != NULLCOMMITLSN)
lip->li_ops->iop_committing(lip, commit_lsn);
if (abort)
set_bit(XFS_LI_ABORTED, &lip->li_flags);
lip->li_ops->iop_unlock(lip);
}
}
static inline void
xfs_log_item_batch_insert(
struct xfs_ail *ailp,
struct xfs_ail_cursor *cur,
struct xfs_log_item **log_items,
int nr_items,
xfs_lsn_t commit_lsn)
{
int i;
spin_lock(&ailp->ail_lock);
/* xfs_trans_ail_update_bulk drops ailp->ail_lock */
xfs_trans_ail_update_bulk(ailp, cur, log_items, nr_items, commit_lsn);
for (i = 0; i < nr_items; i++) {
struct xfs_log_item *lip = log_items[i];
lip->li_ops->iop_unpin(lip, 0);
}
}
/*
* Bulk operation version of xfs_trans_committed that takes a log vector of
* items to insert into the AIL. This uses bulk AIL insertion techniques to
* minimise lock traffic.
*
* If we are called with the aborted flag set, it is because a log write during
* a CIL checkpoint commit has failed. In this case, all the items in the
* checkpoint have already gone through iop_commited and iop_unlock, which
* means that checkpoint commit abort handling is treated exactly the same
* as an iclog write error even though we haven't started any IO yet. Hence in
* this case all we need to do is iop_committed processing, followed by an
* iop_unpin(aborted) call.
*
* The AIL cursor is used to optimise the insert process. If commit_lsn is not
* at the end of the AIL, the insert cursor avoids the need to walk
* the AIL to find the insertion point on every xfs_log_item_batch_insert()
* call. This saves a lot of needless list walking and is a net win, even
* though it slightly increases that amount of AIL lock traffic to set it up
* and tear it down.
*/
void
xfs_trans_committed_bulk(
struct xfs_ail *ailp,
struct xfs_log_vec *log_vector,
xfs_lsn_t commit_lsn,
int aborted)
{
#define LOG_ITEM_BATCH_SIZE 32
struct xfs_log_item *log_items[LOG_ITEM_BATCH_SIZE];
struct xfs_log_vec *lv;
struct xfs_ail_cursor cur;
int i = 0;
spin_lock(&ailp->ail_lock);
xfs_trans_ail_cursor_last(ailp, &cur, commit_lsn);
spin_unlock(&ailp->ail_lock);
/* unpin all the log items */
for (lv = log_vector; lv; lv = lv->lv_next ) {
struct xfs_log_item *lip = lv->lv_item;
xfs_lsn_t item_lsn;
if (aborted)
set_bit(XFS_LI_ABORTED, &lip->li_flags);
item_lsn = lip->li_ops->iop_committed(lip, commit_lsn);
/* item_lsn of -1 means the item needs no further processing */
if (XFS_LSN_CMP(item_lsn, (xfs_lsn_t)-1) == 0)
continue;
/*
* if we are aborting the operation, no point in inserting the
* object into the AIL as we are in a shutdown situation.
*/
if (aborted) {
ASSERT(XFS_FORCED_SHUTDOWN(ailp->ail_mount));
lip->li_ops->iop_unpin(lip, 1);
continue;
}
if (item_lsn != commit_lsn) {
/*
* Not a bulk update option due to unusual item_lsn.
* Push into AIL immediately, rechecking the lsn once
* we have the ail lock. Then unpin the item. This does
* not affect the AIL cursor the bulk insert path is
* using.
*/
spin_lock(&ailp->ail_lock);
if (XFS_LSN_CMP(item_lsn, lip->li_lsn) > 0)
xfs_trans_ail_update(ailp, lip, item_lsn);
else
spin_unlock(&ailp->ail_lock);
lip->li_ops->iop_unpin(lip, 0);
continue;
}
/* Item is a candidate for bulk AIL insert. */
log_items[i++] = lv->lv_item;
if (i >= LOG_ITEM_BATCH_SIZE) {
xfs_log_item_batch_insert(ailp, &cur, log_items,
LOG_ITEM_BATCH_SIZE, commit_lsn);
i = 0;
}
}
/* make sure we insert the remainder! */
if (i)
xfs_log_item_batch_insert(ailp, &cur, log_items, i, commit_lsn);
spin_lock(&ailp->ail_lock);
xfs_trans_ail_cursor_done(&cur);
spin_unlock(&ailp->ail_lock);
}
/*
* Commit the given transaction to the log.
*
* XFS disk error handling mechanism is not based on a typical
* transaction abort mechanism. Logically after the filesystem
* gets marked 'SHUTDOWN', we can't let any new transactions
* be durable - ie. committed to disk - because some metadata might
* be inconsistent. In such cases, this returns an error, and the
* caller may assume that all locked objects joined to the transaction
* have already been unlocked as if the commit had succeeded.
* Do not reference the transaction structure after this call.
*/
static int
__xfs_trans_commit(
struct xfs_trans *tp,
bool regrant)
{
struct xfs_mount *mp = tp->t_mountp;
xfs_lsn_t commit_lsn = -1;
int error = 0;
int sync = tp->t_flags & XFS_TRANS_SYNC;
trace_xfs_trans_commit(tp, _RET_IP_);
/*
* Finish deferred items on final commit. Only permanent transactions
* should ever have deferred ops.
*/
WARN_ON_ONCE(!list_empty(&tp->t_dfops) &&
!(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
if (!regrant && (tp->t_flags & XFS_TRANS_PERM_LOG_RES)) {
error = xfs_defer_finish_noroll(&tp);
if (error)
goto out_unreserve;
}
/*
* If there is nothing to be logged by the transaction,
* then unlock all of the items associated with the
* transaction and free the transaction structure.
* Also make sure to return any reserved blocks to
* the free pool.
*/
if (!(tp->t_flags & XFS_TRANS_DIRTY))
goto out_unreserve;
if (XFS_FORCED_SHUTDOWN(mp)) {
error = -EIO;
goto out_unreserve;
}
ASSERT(tp->t_ticket != NULL);
/*
* If we need to update the superblock, then do it now.
*/
if (tp->t_flags & XFS_TRANS_SB_DIRTY)
xfs_trans_apply_sb_deltas(tp);
xfs_trans_apply_dquot_deltas(tp);
xfs_log_commit_cil(mp, tp, &commit_lsn, regrant);
current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
xfs_trans_free(tp);
/*
* If the transaction needs to be synchronous, then force the
* log out now and wait for it.
*/
if (sync) {
error = xfs_log_force_lsn(mp, commit_lsn, XFS_LOG_SYNC, NULL);
XFS_STATS_INC(mp, xs_trans_sync);
} else {
XFS_STATS_INC(mp, xs_trans_async);
}
return error;
out_unreserve:
xfs_trans_unreserve_and_mod_sb(tp);
/*
* It is indeed possible for the transaction to be not dirty but
* the dqinfo portion to be. All that means is that we have some
* (non-persistent) quota reservations that need to be unreserved.
*/
xfs_trans_unreserve_and_mod_dquots(tp);
if (tp->t_ticket) {
commit_lsn = xfs_log_done(mp, tp->t_ticket, NULL, regrant);
if (commit_lsn == -1 && !error)
error = -EIO;
tp->t_ticket = NULL;
}
current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
xfs_trans_free_items(tp, NULLCOMMITLSN, !!error);
xfs_trans_free(tp);
XFS_STATS_INC(mp, xs_trans_empty);
return error;
}
int
xfs_trans_commit(
struct xfs_trans *tp)
{
return __xfs_trans_commit(tp, false);
}
/*
* Unlock all of the transaction's items and free the transaction.
* The transaction must not have modified any of its items, because
* there is no way to restore them to their previous state.
*
* If the transaction has made a log reservation, make sure to release
* it as well.
*/
void
xfs_trans_cancel(
struct xfs_trans *tp)
{
struct xfs_mount *mp = tp->t_mountp;
bool dirty = (tp->t_flags & XFS_TRANS_DIRTY);
trace_xfs_trans_cancel(tp, _RET_IP_);
if (tp->t_flags & XFS_TRANS_PERM_LOG_RES)
xfs_defer_cancel(tp);
/*
* See if the caller is relying on us to shut down the
* filesystem. This happens in paths where we detect
* corruption and decide to give up.
*/
if (dirty && !XFS_FORCED_SHUTDOWN(mp)) {
XFS_ERROR_REPORT("xfs_trans_cancel", XFS_ERRLEVEL_LOW, mp);
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_INCORE);
}
#ifdef DEBUG
if (!dirty && !XFS_FORCED_SHUTDOWN(mp)) {
struct xfs_log_item *lip;
list_for_each_entry(lip, &tp->t_items, li_trans)
ASSERT(!(lip->li_type == XFS_LI_EFD));
}
#endif
xfs_trans_unreserve_and_mod_sb(tp);
xfs_trans_unreserve_and_mod_dquots(tp);
if (tp->t_ticket) {
xfs_log_done(mp, tp->t_ticket, NULL, false);
tp->t_ticket = NULL;
}
/* mark this thread as no longer being in a transaction */
current_restore_flags_nested(&tp->t_pflags, PF_MEMALLOC_NOFS);
xfs_trans_free_items(tp, NULLCOMMITLSN, dirty);
xfs_trans_free(tp);
}
/*
* Roll from one trans in the sequence of PERMANENT transactions to
* the next: permanent transactions are only flushed out when
* committed with xfs_trans_commit(), but we still want as soon
* as possible to let chunks of it go to the log. So we commit the
* chunk we've been working on and get a new transaction to continue.
*/
int
xfs_trans_roll(
struct xfs_trans **tpp)
{
struct xfs_trans *trans = *tpp;
struct xfs_trans_res tres;
int error;
trace_xfs_trans_roll(trans, _RET_IP_);
/*
* Copy the critical parameters from one trans to the next.
*/
tres.tr_logres = trans->t_log_res;
tres.tr_logcount = trans->t_log_count;
*tpp = xfs_trans_dup(trans);
/*
* Commit the current transaction.
* If this commit failed, then it'd just unlock those items that
* are not marked ihold. That also means that a filesystem shutdown
* is in progress. The caller takes the responsibility to cancel
* the duplicate transaction that gets returned.
*/
error = __xfs_trans_commit(trans, true);
if (error)
return error;
/*
* Reserve space in the log for the next transaction.
* This also pushes items in the "AIL", the list of logged items,
* out to disk if they are taking up space at the tail of the log
* that we want to use. This requires that either nothing be locked
* across this call, or that anything that is locked be logged in
* the prior and the next transactions.
*/
tres.tr_logflags = XFS_TRANS_PERM_LOG_RES;
return xfs_trans_reserve(*tpp, &tres, 0, 0);
}