linux/fs/xfs/xfs_trans.c
Dave Chinner 71e330b593 xfs: Introduce delayed logging core code
The delayed logging code only changes in-memory structures and as
such can be enabled and disabled with a mount option. Add the mount
option and emit a warning that this is an experimental feature that
should not be used in production yet.

We also need infrastructure to track committed items that have not
yet been written to the log. This is what the Committed Item List
(CIL) is for.

The log item also needs to be extended to track the current log
vector, the associated memory buffer and it's location in the Commit
Item List. Extend the log item and log vector structures to enable
this tracking.

To maintain the current log format for transactions with delayed
logging, we need to introduce a checkpoint transaction and a context
for tracking each checkpoint from initiation to transaction
completion.  This includes adding a log ticket for tracking space
log required/used by the context checkpoint.

To track all the changes we need an io vector array per log item,
rather than a single array for the entire transaction. Using the new
log vector structure for this requires two passes - the first to
allocate the log vector structures and chain them together, and the
second to fill them out.  This log vector chain can then be passed
to the CIL for formatting, pinning and insertion into the CIL.

Formatting of the log vector chain is relatively simple - it's just
a loop over the iovecs on each log vector, but it is made slightly
more complex because we re-write the iovec after the copy to point
back at the memory buffer we just copied into.

This code also needs to pin log items. If the log item is not
already tracked in this checkpoint context, then it needs to be
pinned. Otherwise it is already pinned and we don't need to pin it
again.

The only other complexity is calculating the amount of new log space
the formatting has consumed. This needs to be accounted to the
transaction in progress, and the accounting is made more complex
becase we need also to steal space from it for log metadata in the
checkpoint transaction. Calculate all this at insert time and update
all the tickets, counters, etc correctly.

Once we've formatted all the log items in the transaction, attach
the busy extents to the checkpoint context so the busy extents live
until checkpoint completion and can be processed at that point in
time. Transactions can then be freed at this point in time.

Now we need to issue checkpoints - we are tracking the amount of log space
used by the items in the CIL, so we can trigger background checkpoints when the
space usage gets to a certain threshold. Otherwise, checkpoints need ot be
triggered when a log synchronisation point is reached - a log force event.

Because the log write code already handles chained log vectors, writing the
transaction is trivial, too. Construct a transaction header, add it
to the head of the chain and write it into the log, then issue a
commit record write. Then we can release the checkpoint log ticket
and attach the context to the log buffer so it can be called during
Io completion to complete the checkpoint.

We also need to allow for synchronising multiple in-flight
checkpoints. This is needed for two things - the first is to ensure
that checkpoint commit records appear in the log in the correct
sequence order (so they are replayed in the correct order). The
second is so that xfs_log_force_lsn() operates correctly and only
flushes and/or waits for the specific sequence it was provided with.

To do this we need a wait variable and a list tracking the
checkpoint commits in progress. We can walk this list and wait for
the checkpoints to change state or complete easily, an this provides
the necessary synchronisation for correct operation in both cases.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Alex Elder <aelder@sgi.com>
2010-05-24 10:38:03 -05:00

1487 lines
40 KiB
C

/*
* Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
* All Rights Reserved.
*
* 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.
*
* 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_types.h"
#include "xfs_bit.h"
#include "xfs_log.h"
#include "xfs_inum.h"
#include "xfs_trans.h"
#include "xfs_sb.h"
#include "xfs_ag.h"
#include "xfs_dir2.h"
#include "xfs_dmapi.h"
#include "xfs_mount.h"
#include "xfs_error.h"
#include "xfs_da_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_alloc_btree.h"
#include "xfs_ialloc_btree.h"
#include "xfs_dir2_sf.h"
#include "xfs_attr_sf.h"
#include "xfs_dinode.h"
#include "xfs_inode.h"
#include "xfs_btree.h"
#include "xfs_ialloc.h"
#include "xfs_alloc.h"
#include "xfs_bmap.h"
#include "xfs_quota.h"
#include "xfs_trans_priv.h"
#include "xfs_trans_space.h"
#include "xfs_inode_item.h"
#include "xfs_trace.h"
kmem_zone_t *xfs_trans_zone;
/*
* Reservation functions here avoid a huge stack in xfs_trans_init
* due to register overflow from temporaries in the calculations.
*/
STATIC uint
xfs_calc_write_reservation(xfs_mount_t *mp)
{
return XFS_CALC_WRITE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_itruncate_reservation(xfs_mount_t *mp)
{
return XFS_CALC_ITRUNCATE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_rename_reservation(xfs_mount_t *mp)
{
return XFS_CALC_RENAME_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_link_reservation(xfs_mount_t *mp)
{
return XFS_CALC_LINK_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_remove_reservation(xfs_mount_t *mp)
{
return XFS_CALC_REMOVE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_symlink_reservation(xfs_mount_t *mp)
{
return XFS_CALC_SYMLINK_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_create_reservation(xfs_mount_t *mp)
{
return XFS_CALC_CREATE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_mkdir_reservation(xfs_mount_t *mp)
{
return XFS_CALC_MKDIR_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_ifree_reservation(xfs_mount_t *mp)
{
return XFS_CALC_IFREE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_ichange_reservation(xfs_mount_t *mp)
{
return XFS_CALC_ICHANGE_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_growdata_reservation(xfs_mount_t *mp)
{
return XFS_CALC_GROWDATA_LOG_RES(mp);
}
STATIC uint
xfs_calc_growrtalloc_reservation(xfs_mount_t *mp)
{
return XFS_CALC_GROWRTALLOC_LOG_RES(mp);
}
STATIC uint
xfs_calc_growrtzero_reservation(xfs_mount_t *mp)
{
return XFS_CALC_GROWRTZERO_LOG_RES(mp);
}
STATIC uint
xfs_calc_growrtfree_reservation(xfs_mount_t *mp)
{
return XFS_CALC_GROWRTFREE_LOG_RES(mp);
}
STATIC uint
xfs_calc_swrite_reservation(xfs_mount_t *mp)
{
return XFS_CALC_SWRITE_LOG_RES(mp);
}
STATIC uint
xfs_calc_writeid_reservation(xfs_mount_t *mp)
{
return XFS_CALC_WRITEID_LOG_RES(mp);
}
STATIC uint
xfs_calc_addafork_reservation(xfs_mount_t *mp)
{
return XFS_CALC_ADDAFORK_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_attrinval_reservation(xfs_mount_t *mp)
{
return XFS_CALC_ATTRINVAL_LOG_RES(mp);
}
STATIC uint
xfs_calc_attrset_reservation(xfs_mount_t *mp)
{
return XFS_CALC_ATTRSET_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_attrrm_reservation(xfs_mount_t *mp)
{
return XFS_CALC_ATTRRM_LOG_RES(mp) + XFS_DQUOT_LOGRES(mp);
}
STATIC uint
xfs_calc_clear_agi_bucket_reservation(xfs_mount_t *mp)
{
return XFS_CALC_CLEAR_AGI_BUCKET_LOG_RES(mp);
}
/*
* Initialize the precomputed transaction reservation values
* in the mount structure.
*/
void
xfs_trans_init(
xfs_mount_t *mp)
{
xfs_trans_reservations_t *resp;
resp = &(mp->m_reservations);
resp->tr_write = xfs_calc_write_reservation(mp);
resp->tr_itruncate = xfs_calc_itruncate_reservation(mp);
resp->tr_rename = xfs_calc_rename_reservation(mp);
resp->tr_link = xfs_calc_link_reservation(mp);
resp->tr_remove = xfs_calc_remove_reservation(mp);
resp->tr_symlink = xfs_calc_symlink_reservation(mp);
resp->tr_create = xfs_calc_create_reservation(mp);
resp->tr_mkdir = xfs_calc_mkdir_reservation(mp);
resp->tr_ifree = xfs_calc_ifree_reservation(mp);
resp->tr_ichange = xfs_calc_ichange_reservation(mp);
resp->tr_growdata = xfs_calc_growdata_reservation(mp);
resp->tr_swrite = xfs_calc_swrite_reservation(mp);
resp->tr_writeid = xfs_calc_writeid_reservation(mp);
resp->tr_addafork = xfs_calc_addafork_reservation(mp);
resp->tr_attrinval = xfs_calc_attrinval_reservation(mp);
resp->tr_attrset = xfs_calc_attrset_reservation(mp);
resp->tr_attrrm = xfs_calc_attrrm_reservation(mp);
resp->tr_clearagi = xfs_calc_clear_agi_bucket_reservation(mp);
resp->tr_growrtalloc = xfs_calc_growrtalloc_reservation(mp);
resp->tr_growrtzero = xfs_calc_growrtzero_reservation(mp);
resp->tr_growrtfree = xfs_calc_growrtfree_reservation(mp);
}
/*
* This routine is called to allocate a transaction structure.
* The type parameter indicates the type of the transaction. These
* are enumerated in xfs_trans.h.
*
* Dynamically allocate the transaction structure from the transaction
* zone, initialize it, and return it to the caller.
*/
xfs_trans_t *
xfs_trans_alloc(
xfs_mount_t *mp,
uint type)
{
xfs_wait_for_freeze(mp, SB_FREEZE_TRANS);
return _xfs_trans_alloc(mp, type, KM_SLEEP);
}
xfs_trans_t *
_xfs_trans_alloc(
xfs_mount_t *mp,
uint type,
uint memflags)
{
xfs_trans_t *tp;
atomic_inc(&mp->m_active_trans);
tp = kmem_zone_zalloc(xfs_trans_zone, memflags);
tp->t_magic = XFS_TRANS_MAGIC;
tp->t_type = type;
tp->t_mountp = mp;
tp->t_items_free = XFS_LIC_NUM_SLOTS;
xfs_lic_init(&(tp->t_items));
INIT_LIST_HEAD(&tp->t_busy);
return tp;
}
/*
* 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)
{
struct xfs_busy_extent *busyp, *n;
list_for_each_entry_safe(busyp, n, &tp->t_busy, list)
xfs_alloc_busy_clear(tp->t_mountp, busyp);
atomic_dec(&tp->t_mountp->m_active_trans);
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.
*/
xfs_trans_t *
xfs_trans_dup(
xfs_trans_t *tp)
{
xfs_trans_t *ntp;
ntp = kmem_zone_zalloc(xfs_trans_zone, KM_SLEEP);
/*
* Initialize the new transaction structure.
*/
ntp->t_magic = XFS_TRANS_MAGIC;
ntp->t_type = tp->t_type;
ntp->t_mountp = tp->t_mountp;
ntp->t_items_free = XFS_LIC_NUM_SLOTS;
xfs_lic_init(&(ntp->t_items));
INIT_LIST_HEAD(&ntp->t_busy);
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);
ntp->t_ticket = xfs_log_ticket_get(tp->t_ticket);
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;
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.
*/
int
xfs_trans_reserve(
xfs_trans_t *tp,
uint blocks,
uint logspace,
uint rtextents,
uint flags,
uint logcount)
{
int log_flags;
int error = 0;
int rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
/* Mark this thread as being in a transaction */
current_set_flags_nested(&tp->t_pflags, PF_FSTRANS);
/*
* 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_incore_sb(tp->t_mountp, XFS_SBS_FDBLOCKS,
-((int64_t)blocks), rsvd);
if (error != 0) {
current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
return (XFS_ERROR(ENOSPC));
}
tp->t_blk_res += blocks;
}
/*
* Reserve the log space needed for this transaction.
*/
if (logspace > 0) {
ASSERT((tp->t_log_res == 0) || (tp->t_log_res == logspace));
ASSERT((tp->t_log_count == 0) ||
(tp->t_log_count == logcount));
if (flags & XFS_TRANS_PERM_LOG_RES) {
log_flags = XFS_LOG_PERM_RESERV;
tp->t_flags |= XFS_TRANS_PERM_LOG_RES;
} else {
ASSERT(tp->t_ticket == NULL);
ASSERT(!(tp->t_flags & XFS_TRANS_PERM_LOG_RES));
log_flags = 0;
}
error = xfs_log_reserve(tp->t_mountp, logspace, logcount,
&tp->t_ticket,
XFS_TRANSACTION, log_flags, tp->t_type);
if (error) {
goto undo_blocks;
}
tp->t_log_res = logspace;
tp->t_log_count = 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_incore_sb(tp->t_mountp, XFS_SBS_FREXTENTS,
-((int64_t)rtextents), rsvd);
if (error) {
error = XFS_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 (logspace > 0) {
if (flags & XFS_TRANS_PERM_LOG_RES) {
log_flags = XFS_LOG_REL_PERM_RESERV;
} else {
log_flags = 0;
}
xfs_log_done(tp->t_mountp, tp->t_ticket, NULL, log_flags);
tp->t_ticket = NULL;
tp->t_log_res = 0;
tp->t_flags &= ~XFS_TRANS_PERM_LOG_RES;
}
undo_blocks:
if (blocks > 0) {
(void) xfs_mod_incore_sb(tp->t_mountp, XFS_SBS_FDBLOCKS,
(int64_t)blocks, rsvd);
tp->t_blk_res = 0;
}
current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
return error;
}
/*
* 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 (delta < 0) {
tp->t_blk_res_used += (uint)-delta;
ASSERT(tp->t_blk_res_used <= tp->t_blk_res);
}
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.
*/
ASSERT(delta < 0);
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;
}
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);
}
/*
* 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.
*
* This is done efficiently with a single call to xfs_mod_incore_sb_batch().
* However, we have to ensure that we only modify each superblock field only
* once because the application of the delta values may not be atomic. That can
* lead to ENOSPC races occurring if we have two separate modifcations of the
* free space counter to put back the entire reservation and then take away
* what we used.
*
* 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(
xfs_trans_t *tp)
{
xfs_mod_sb_t msb[14]; /* If you add cases, add entries */
xfs_mod_sb_t *msbp;
xfs_mount_t *mp = tp->t_mountp;
/* REFERENCED */
int error;
int rsvd;
int64_t blkdelta = 0;
int64_t rtxdelta = 0;
msbp = msb;
rsvd = (tp->t_flags & XFS_TRANS_RESERVE) != 0;
/* calculate free blocks delta */
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 (blkdelta != 0) {
msbp->msb_field = XFS_SBS_FDBLOCKS;
msbp->msb_delta = blkdelta;
msbp++;
}
/* calculate free realtime extents 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 (rtxdelta != 0) {
msbp->msb_field = XFS_SBS_FREXTENTS;
msbp->msb_delta = rtxdelta;
msbp++;
}
/* apply remaining deltas */
if (xfs_sb_version_haslazysbcount(&mp->m_sb) ||
(tp->t_flags & XFS_TRANS_SB_DIRTY)) {
if (tp->t_icount_delta != 0) {
msbp->msb_field = XFS_SBS_ICOUNT;
msbp->msb_delta = tp->t_icount_delta;
msbp++;
}
if (tp->t_ifree_delta != 0) {
msbp->msb_field = XFS_SBS_IFREE;
msbp->msb_delta = tp->t_ifree_delta;
msbp++;
}
}
if (tp->t_flags & XFS_TRANS_SB_DIRTY) {
if (tp->t_dblocks_delta != 0) {
msbp->msb_field = XFS_SBS_DBLOCKS;
msbp->msb_delta = tp->t_dblocks_delta;
msbp++;
}
if (tp->t_agcount_delta != 0) {
msbp->msb_field = XFS_SBS_AGCOUNT;
msbp->msb_delta = tp->t_agcount_delta;
msbp++;
}
if (tp->t_imaxpct_delta != 0) {
msbp->msb_field = XFS_SBS_IMAX_PCT;
msbp->msb_delta = tp->t_imaxpct_delta;
msbp++;
}
if (tp->t_rextsize_delta != 0) {
msbp->msb_field = XFS_SBS_REXTSIZE;
msbp->msb_delta = tp->t_rextsize_delta;
msbp++;
}
if (tp->t_rbmblocks_delta != 0) {
msbp->msb_field = XFS_SBS_RBMBLOCKS;
msbp->msb_delta = tp->t_rbmblocks_delta;
msbp++;
}
if (tp->t_rblocks_delta != 0) {
msbp->msb_field = XFS_SBS_RBLOCKS;
msbp->msb_delta = tp->t_rblocks_delta;
msbp++;
}
if (tp->t_rextents_delta != 0) {
msbp->msb_field = XFS_SBS_REXTENTS;
msbp->msb_delta = tp->t_rextents_delta;
msbp++;
}
if (tp->t_rextslog_delta != 0) {
msbp->msb_field = XFS_SBS_REXTSLOG;
msbp->msb_delta = tp->t_rextslog_delta;
msbp++;
}
}
/*
* If we need to change anything, do it.
*/
if (msbp > msb) {
error = xfs_mod_incore_sb_batch(tp->t_mountp, msb,
(uint)(msbp - msb), rsvd);
ASSERT(error == 0);
}
}
/*
* Total up the number of log iovecs needed to commit this
* transaction. The transaction itself needs one for the
* transaction header. Ask each dirty item in turn how many
* it needs to get the total.
*/
static uint
xfs_trans_count_vecs(
struct xfs_trans *tp)
{
int nvecs;
xfs_log_item_desc_t *lidp;
nvecs = 1;
lidp = xfs_trans_first_item(tp);
ASSERT(lidp != NULL);
/* In the non-debug case we need to start bailing out if we
* didn't find a log_item here, return zero and let trans_commit
* deal with it.
*/
if (lidp == NULL)
return 0;
while (lidp != NULL) {
/*
* Skip items which aren't dirty in this transaction.
*/
if (!(lidp->lid_flags & XFS_LID_DIRTY)) {
lidp = xfs_trans_next_item(tp, lidp);
continue;
}
lidp->lid_size = IOP_SIZE(lidp->lid_item);
nvecs += lidp->lid_size;
lidp = xfs_trans_next_item(tp, lidp);
}
return nvecs;
}
/*
* Fill in the vector with pointers to data to be logged
* by this transaction. The transaction header takes
* the first vector, and then each dirty item takes the
* number of vectors it indicated it needed in xfs_trans_count_vecs().
*
* As each item fills in the entries it needs, also pin the item
* so that it cannot be flushed out until the log write completes.
*/
static void
xfs_trans_fill_vecs(
struct xfs_trans *tp,
struct xfs_log_iovec *log_vector)
{
xfs_log_item_desc_t *lidp;
struct xfs_log_iovec *vecp;
uint nitems;
/*
* Skip over the entry for the transaction header, we'll
* fill that in at the end.
*/
vecp = log_vector + 1;
nitems = 0;
lidp = xfs_trans_first_item(tp);
ASSERT(lidp);
while (lidp) {
/* Skip items which aren't dirty in this transaction. */
if (!(lidp->lid_flags & XFS_LID_DIRTY)) {
lidp = xfs_trans_next_item(tp, lidp);
continue;
}
/*
* The item may be marked dirty but not log anything. This can
* be used to get called when a transaction is committed.
*/
if (lidp->lid_size)
nitems++;
IOP_FORMAT(lidp->lid_item, vecp);
vecp += lidp->lid_size;
IOP_PIN(lidp->lid_item);
lidp = xfs_trans_next_item(tp, lidp);
}
/*
* Now that we've counted the number of items in this transaction, fill
* in the transaction header. Note that the transaction header does not
* have a log item.
*/
tp->t_header.th_magic = XFS_TRANS_HEADER_MAGIC;
tp->t_header.th_type = tp->t_type;
tp->t_header.th_num_items = nitems;
log_vector->i_addr = (xfs_caddr_t)&tp->t_header;
log_vector->i_len = sizeof(xfs_trans_header_t);
log_vector->i_type = XLOG_REG_TYPE_TRANSHDR;
}
/*
* The committed item processing consists of calling the committed routine of
* each logged item, updating the item's position in the AIL if necessary, and
* unpinning each item. If the committed routine returns -1, then do nothing
* further with the item because it may have been freed.
*
* Since items are unlocked when they are copied to the incore log, it is
* possible for two transactions to be completing and manipulating the same
* item simultaneously. The AIL lock will protect the lsn field of each item.
* The value of this field can never go backwards.
*
* We unpin the items after repositioning them in the AIL, because otherwise
* they could be immediately flushed and we'd have to race with the flusher
* trying to pull the item from the AIL as we add it.
*/
void
xfs_trans_item_committed(
struct xfs_log_item *lip,
xfs_lsn_t commit_lsn,
int aborted)
{
xfs_lsn_t item_lsn;
struct xfs_ail *ailp;
if (aborted)
lip->li_flags |= XFS_LI_ABORTED;
item_lsn = IOP_COMMITTED(lip, commit_lsn);
/* If the committed routine returns -1, item has been freed. */
if (XFS_LSN_CMP(item_lsn, (xfs_lsn_t)-1) == 0)
return;
/*
* If the returned lsn is greater than what it contained before, update
* the location of the item in the AIL. If it is not, then do nothing.
* Items can never move backwards in the AIL.
*
* While the new lsn should usually be greater, it is possible that a
* later transaction completing simultaneously with an earlier one
* using the same item could complete first with a higher lsn. This
* would cause the earlier transaction to fail the test below.
*/
ailp = lip->li_ailp;
spin_lock(&ailp->xa_lock);
if (XFS_LSN_CMP(item_lsn, lip->li_lsn) > 0) {
/*
* This will set the item's lsn to item_lsn and update the
* position of the item in the AIL.
*
* xfs_trans_ail_update() drops the AIL lock.
*/
xfs_trans_ail_update(ailp, lip, item_lsn);
} else {
spin_unlock(&ailp->xa_lock);
}
/*
* Now that we've repositioned the item in the AIL, unpin it so it can
* be flushed. Pass information about buffer stale state down from the
* log item flags, if anyone else stales the buffer we do not want to
* pay any attention to it.
*/
IOP_UNPIN(lip);
}
/*
* This is typically called by the LM when a transaction has been fully
* committed to disk. It needs to unpin the items which have
* been logged by the transaction and update their positions
* in the AIL if necessary.
*
* This also gets called when the transactions didn't get written out
* because of an I/O error. Abortflag & XFS_LI_ABORTED is set then.
*/
STATIC void
xfs_trans_committed(
struct xfs_trans *tp,
int abortflag)
{
xfs_log_item_desc_t *lidp;
xfs_log_item_chunk_t *licp;
xfs_log_item_chunk_t *next_licp;
/* Call the transaction's completion callback if there is one. */
if (tp->t_callback != NULL)
tp->t_callback(tp, tp->t_callarg);
for (lidp = xfs_trans_first_item(tp);
lidp != NULL;
lidp = xfs_trans_next_item(tp, lidp)) {
xfs_trans_item_committed(lidp->lid_item, tp->t_lsn, abortflag);
}
/* free the item chunks, ignoring the embedded chunk */
for (licp = tp->t_items.lic_next; licp != NULL; licp = next_licp) {
next_licp = licp->lic_next;
kmem_free(licp);
}
xfs_trans_free(tp);
}
/*
* Called from the trans_commit code when we notice that
* the filesystem is in the middle of a forced shutdown.
*/
STATIC void
xfs_trans_uncommit(
struct xfs_trans *tp,
uint flags)
{
xfs_log_item_desc_t *lidp;
for (lidp = xfs_trans_first_item(tp);
lidp != NULL;
lidp = xfs_trans_next_item(tp, lidp)) {
/*
* Unpin all but those that aren't dirty.
*/
if (lidp->lid_flags & XFS_LID_DIRTY)
IOP_UNPIN_REMOVE(lidp->lid_item, tp);
}
xfs_trans_unreserve_and_mod_sb(tp);
xfs_trans_unreserve_and_mod_dquots(tp);
xfs_trans_free_items(tp, NULLCOMMITLSN, flags);
xfs_trans_free(tp);
}
/*
* Format the transaction direct to the iclog. This isolates the physical
* transaction commit operation from the logical operation and hence allows
* other methods to be introduced without affecting the existing commit path.
*/
static int
xfs_trans_commit_iclog(
struct xfs_mount *mp,
struct xfs_trans *tp,
xfs_lsn_t *commit_lsn,
int flags)
{
int shutdown;
int error;
int log_flags = 0;
struct xlog_in_core *commit_iclog;
#define XFS_TRANS_LOGVEC_COUNT 16
struct xfs_log_iovec log_vector_fast[XFS_TRANS_LOGVEC_COUNT];
struct xfs_log_iovec *log_vector;
uint nvec;
/*
* Ask each log item how many log_vector entries it will
* need so we can figure out how many to allocate.
* Try to avoid the kmem_alloc() call in the common case
* by using a vector from the stack when it fits.
*/
nvec = xfs_trans_count_vecs(tp);
if (nvec == 0) {
return ENOMEM; /* triggers a shutdown! */
} else if (nvec <= XFS_TRANS_LOGVEC_COUNT) {
log_vector = log_vector_fast;
} else {
log_vector = (xfs_log_iovec_t *)kmem_alloc(nvec *
sizeof(xfs_log_iovec_t),
KM_SLEEP);
}
/*
* Fill in the log_vector and pin the logged items, and
* then write the transaction to the log.
*/
xfs_trans_fill_vecs(tp, log_vector);
if (flags & XFS_TRANS_RELEASE_LOG_RES)
log_flags = XFS_LOG_REL_PERM_RESERV;
error = xfs_log_write(mp, log_vector, nvec, tp->t_ticket, &(tp->t_lsn));
/*
* The transaction is committed incore here, and can go out to disk
* at any time after this call. However, all the items associated
* with the transaction are still locked and pinned in memory.
*/
*commit_lsn = xfs_log_done(mp, tp->t_ticket, &commit_iclog, log_flags);
tp->t_commit_lsn = *commit_lsn;
trace_xfs_trans_commit_lsn(tp);
if (nvec > XFS_TRANS_LOGVEC_COUNT)
kmem_free(log_vector);
/*
* If we got a log write error. Unpin the logitems that we
* had pinned, clean up, free trans structure, and return error.
*/
if (error || *commit_lsn == -1) {
current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
xfs_trans_uncommit(tp, flags|XFS_TRANS_ABORT);
return XFS_ERROR(EIO);
}
/*
* Once the transaction has committed, unused
* reservations need to be released and changes to
* the superblock need to be reflected in the in-core
* version. Do that now.
*/
xfs_trans_unreserve_and_mod_sb(tp);
/*
* Tell the LM to call the transaction completion routine
* when the log write with LSN commit_lsn completes (e.g.
* when the transaction commit really hits the on-disk log).
* After this call we cannot reference tp, because the call
* can happen at any time and the call will free the transaction
* structure pointed to by tp. The only case where we call
* the completion routine (xfs_trans_committed) directly is
* if the log is turned off on a debug kernel or we're
* running in simulation mode (the log is explicitly turned
* off).
*/
tp->t_logcb.cb_func = (void(*)(void*, int))xfs_trans_committed;
tp->t_logcb.cb_arg = tp;
/*
* We need to pass the iclog buffer which was used for the
* transaction commit record into this function, and attach
* the callback to it. The callback must be attached before
* the items are unlocked to avoid racing with other threads
* waiting for an item to unlock.
*/
shutdown = xfs_log_notify(mp, commit_iclog, &(tp->t_logcb));
/*
* Mark this thread as no longer being in a transaction
*/
current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
/*
* Once all the items of the transaction have been copied
* to the in core log and the callback is attached, the
* items can be unlocked.
*
* This will free descriptors pointing to items which were
* not logged since there is nothing more to do with them.
* For items which were logged, we will keep pointers to them
* so they can be unpinned after the transaction commits to disk.
* This will also stamp each modified meta-data item with
* the commit lsn of this transaction for dependency tracking
* purposes.
*/
xfs_trans_unlock_items(tp, *commit_lsn);
/*
* If we detected a log error earlier, finish committing
* the transaction now (unpin log items, etc).
*
* Order is critical here, to avoid using the transaction
* pointer after its been freed (by xfs_trans_committed
* either here now, or as a callback). We cannot do this
* step inside xfs_log_notify as was done earlier because
* of this issue.
*/
if (shutdown)
xfs_trans_committed(tp, XFS_LI_ABORTED);
/*
* Now that the xfs_trans_committed callback has been attached,
* and the items are released we can finally allow the iclog to
* go to disk.
*/
return xfs_log_release_iclog(mp, commit_iclog);
}
/*
* Walk the log items and allocate log vector structures for
* each item large enough to fit all the vectors they require.
* Note that this format differs from the old log vector format in
* that there is no transaction header in these log vectors.
*/
STATIC struct xfs_log_vec *
xfs_trans_alloc_log_vecs(
xfs_trans_t *tp)
{
xfs_log_item_desc_t *lidp;
struct xfs_log_vec *lv = NULL;
struct xfs_log_vec *ret_lv = NULL;
lidp = xfs_trans_first_item(tp);
/* Bail out if we didn't find a log item. */
if (!lidp) {
ASSERT(0);
return NULL;
}
while (lidp != NULL) {
struct xfs_log_vec *new_lv;
/* Skip items which aren't dirty in this transaction. */
if (!(lidp->lid_flags & XFS_LID_DIRTY)) {
lidp = xfs_trans_next_item(tp, lidp);
continue;
}
/* Skip items that do not have any vectors for writing */
lidp->lid_size = IOP_SIZE(lidp->lid_item);
if (!lidp->lid_size) {
lidp = xfs_trans_next_item(tp, lidp);
continue;
}
new_lv = kmem_zalloc(sizeof(*new_lv) +
lidp->lid_size * sizeof(struct xfs_log_iovec),
KM_SLEEP);
/* The allocated iovec region lies beyond the log vector. */
new_lv->lv_iovecp = (struct xfs_log_iovec *)&new_lv[1];
new_lv->lv_niovecs = lidp->lid_size;
new_lv->lv_item = lidp->lid_item;
if (!ret_lv)
ret_lv = new_lv;
else
lv->lv_next = new_lv;
lv = new_lv;
lidp = xfs_trans_next_item(tp, lidp);
}
return ret_lv;
}
static int
xfs_trans_commit_cil(
struct xfs_mount *mp,
struct xfs_trans *tp,
xfs_lsn_t *commit_lsn,
int flags)
{
struct xfs_log_vec *log_vector;
int error;
/*
* Get each log item to allocate a vector structure for
* the log item to to pass to the log write code. The
* CIL commit code will format the vector and save it away.
*/
log_vector = xfs_trans_alloc_log_vecs(tp);
if (!log_vector)
return ENOMEM;
error = xfs_log_commit_cil(mp, tp, log_vector, commit_lsn, flags);
if (error)
return error;
current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
/* xfs_trans_free_items() unlocks them first */
xfs_trans_free_items(tp, *commit_lsn, 0);
xfs_trans_free(tp);
return 0;
}
/*
* xfs_trans_commit
*
* Commit the given transaction to the log a/synchronously.
*
* 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.
*/
int
_xfs_trans_commit(
struct xfs_trans *tp,
uint flags,
int *log_flushed)
{
struct xfs_mount *mp = tp->t_mountp;
xfs_lsn_t commit_lsn = -1;
int error = 0;
int log_flags = 0;
int sync = tp->t_flags & XFS_TRANS_SYNC;
/*
* Determine whether this commit is releasing a permanent
* log reservation or not.
*/
if (flags & XFS_TRANS_RELEASE_LOG_RES) {
ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
log_flags = XFS_LOG_REL_PERM_RESERV;
}
/*
* 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 = XFS_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);
if (mp->m_flags & XFS_MOUNT_DELAYLOG)
error = xfs_trans_commit_cil(mp, tp, &commit_lsn, flags);
else
error = xfs_trans_commit_iclog(mp, tp, &commit_lsn, flags);
if (error == ENOMEM) {
xfs_force_shutdown(mp, SHUTDOWN_LOG_IO_ERROR);
error = XFS_ERROR(EIO);
goto out_unreserve;
}
/*
* If the transaction needs to be synchronous, then force the
* log out now and wait for it.
*/
if (sync) {
if (!error) {
error = _xfs_log_force_lsn(mp, commit_lsn,
XFS_LOG_SYNC, log_flushed);
}
XFS_STATS_INC(xs_trans_sync);
} else {
XFS_STATS_INC(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, log_flags);
if (commit_lsn == -1 && !error)
error = XFS_ERROR(EIO);
}
current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
xfs_trans_free_items(tp, NULLCOMMITLSN, error ? XFS_TRANS_ABORT : 0);
xfs_trans_free(tp);
XFS_STATS_INC(xs_trans_empty);
return error;
}
/*
* 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(
xfs_trans_t *tp,
int flags)
{
int log_flags;
#ifdef DEBUG
xfs_log_item_chunk_t *licp;
xfs_log_item_desc_t *lidp;
xfs_log_item_t *lip;
int i;
#endif
xfs_mount_t *mp = tp->t_mountp;
/*
* See if the caller is being too lazy to figure out if
* the transaction really needs an abort.
*/
if ((flags & XFS_TRANS_ABORT) && !(tp->t_flags & XFS_TRANS_DIRTY))
flags &= ~XFS_TRANS_ABORT;
/*
* 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 ((tp->t_flags & XFS_TRANS_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 (!(flags & XFS_TRANS_ABORT)) {
licp = &(tp->t_items);
while (licp != NULL) {
lidp = licp->lic_descs;
for (i = 0; i < licp->lic_unused; i++, lidp++) {
if (xfs_lic_isfree(licp, i)) {
continue;
}
lip = lidp->lid_item;
if (!XFS_FORCED_SHUTDOWN(mp))
ASSERT(!(lip->li_type == XFS_LI_EFD));
}
licp = licp->lic_next;
}
}
#endif
xfs_trans_unreserve_and_mod_sb(tp);
xfs_trans_unreserve_and_mod_dquots(tp);
if (tp->t_ticket) {
if (flags & XFS_TRANS_RELEASE_LOG_RES) {
ASSERT(tp->t_flags & XFS_TRANS_PERM_LOG_RES);
log_flags = XFS_LOG_REL_PERM_RESERV;
} else {
log_flags = 0;
}
xfs_log_done(mp, tp->t_ticket, NULL, log_flags);
}
/* mark this thread as no longer being in a transaction */
current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
xfs_trans_free_items(tp, NULLCOMMITLSN, flags);
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_RELEASE_LOG_RES, 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_inode *dp)
{
struct xfs_trans *trans;
unsigned int logres, count;
int error;
/*
* Ensure that the inode is always logged.
*/
trans = *tpp;
xfs_trans_log_inode(trans, dp, XFS_ILOG_CORE);
/*
* Copy the critical parameters from one trans to the next.
*/
logres = trans->t_log_res;
count = 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, 0);
if (error)
return (error);
trans = *tpp;
/*
* transaction commit worked ok so we can drop the extra ticket
* reference that we gained in xfs_trans_dup()
*/
xfs_log_ticket_put(trans->t_ticket);
/*
* Reserve space in the log for th 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.
*/
error = xfs_trans_reserve(trans, 0, logres, 0,
XFS_TRANS_PERM_LOG_RES, count);
/*
* Ensure that the inode is in the new transaction and locked.
*/
if (error)
return error;
xfs_trans_ijoin(trans, dp, XFS_ILOCK_EXCL);
xfs_trans_ihold(trans, dp);
return 0;
}