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[XFS] Replace custom AIL linked-list code with struct list_head

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Replace the xfs_ail_entry_t with a struct list_head and clean the
surrounding code up. Also fixes a livelock in xfs_trans_first_push_ail()
by terminating the loop at the head of the list correctly.

SGI-PV: 978682
SGI-Modid: xfs-linux-melb:xfs-kern:30636a

Signed-off-by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
This commit is contained in:
Josef 'Jeff' Sipek 2008-03-27 17:58:27 +11:00 committed by Lachlan McIlroy
parent a45c796867
commit 535f6b3735
3 changed files with 63 additions and 97 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
fs/xfs/xfs_mount.h
View File

@ -220,7 +220,7 @@ extern void xfs_icsb_sync_counters_flags(struct xfs_mount *, int);
#endif
typedef struct xfs_ail {
xfs_ail_entry_t xa_ail;
struct list_head xa_ail;
uint xa_gen;
struct task_struct *xa_task;
xfs_lsn_t xa_target;

7
fs/xfs/xfs_trans.h
View File

@ -113,13 +113,8 @@ struct xfs_mount;
struct xfs_trans;
struct xfs_dquot_acct;
typedef struct xfs_ail_entry {
struct xfs_log_item *ail_forw; /* AIL forw pointer */
struct xfs_log_item *ail_back; /* AIL back pointer */
} xfs_ail_entry_t;
typedef struct xfs_log_item {
xfs_ail_entry_t li_ail; /* AIL pointers */
struct list_head li_ail; /* AIL pointers */
xfs_lsn_t li_lsn; /* last on-disk lsn */
struct xfs_log_item_desc *li_desc; /* ptr to current desc*/
struct xfs_mount *li_mountp; /* ptr to fs mount */

151
fs/xfs/xfs_trans_ail.c
View File

@ -28,13 +28,13 @@
#include "xfs_trans_priv.h"
#include "xfs_error.h"
STATIC void xfs_ail_insert(xfs_ail_entry_t *, xfs_log_item_t *);
STATIC xfs_log_item_t * xfs_ail_delete(xfs_ail_entry_t *, xfs_log_item_t *);
STATIC xfs_log_item_t * xfs_ail_min(xfs_ail_entry_t *);
STATIC xfs_log_item_t * xfs_ail_next(xfs_ail_entry_t *, xfs_log_item_t *);
STATIC void xfs_ail_insert(xfs_ail_t *, xfs_log_item_t *);
STATIC xfs_log_item_t * xfs_ail_delete(xfs_ail_t *, xfs_log_item_t *);
STATIC xfs_log_item_t * xfs_ail_min(xfs_ail_t *);
STATIC xfs_log_item_t * xfs_ail_next(xfs_ail_t *, xfs_log_item_t *);
#ifdef DEBUG
STATIC void xfs_ail_check(xfs_ail_entry_t *, xfs_log_item_t *);
STATIC void xfs_ail_check(xfs_ail_t *, xfs_log_item_t *);
#else
#define xfs_ail_check(a,l)
#endif /* DEBUG */
@ -57,7 +57,7 @@ xfs_trans_tail_ail(
xfs_log_item_t *lip;
spin_lock(&mp->m_ail_lock);
lip = xfs_ail_min(&(mp->m_ail.xa_ail));
lip = xfs_ail_min(&mp->m_ail);
if (lip == NULL) {
lsn = (xfs_lsn_t)0;
} else {
@ -91,7 +91,7 @@ xfs_trans_push_ail(
{
xfs_log_item_t *lip;
lip = xfs_ail_min(&mp->m_ail.xa_ail);
lip = xfs_ail_min(&mp->m_ail);
if (lip && !XFS_FORCED_SHUTDOWN(mp)) {
if (XFS_LSN_CMP(threshold_lsn, mp->m_ail.xa_target) > 0)
xfsaild_wakeup(mp, threshold_lsn);
@ -111,15 +111,17 @@ xfs_trans_first_push_ail(
{
xfs_log_item_t *lip;
lip = xfs_ail_min(&(mp->m_ail.xa_ail));
lip = xfs_ail_min(&mp->m_ail);
*gen = (int)mp->m_ail.xa_gen;
if (lsn == 0)
return lip;
while (lip && (XFS_LSN_CMP(lip->li_lsn, lsn) < 0))
lip = lip->li_ail.ail_forw;
list_for_each_entry(lip, &mp->m_ail.xa_ail, li_ail) {
if (XFS_LSN_CMP(lip->li_lsn, lsn) >= 0)
return lip;
}
return lip;
return NULL;
}
/*
@ -329,7 +331,7 @@ xfs_trans_unlocked_item(
* the call to xfs_log_move_tail() doesn't do anything if there's
* not enough free space to wake people up so we're safe calling it.
*/
min_lip = xfs_ail_min(&mp->m_ail.xa_ail);
min_lip = xfs_ail_min(&mp->m_ail);
if (min_lip == lip)
xfs_log_move_tail(mp, 1);
@ -357,15 +359,13 @@ xfs_trans_update_ail(
xfs_log_item_t *lip,
xfs_lsn_t lsn) __releases(mp->m_ail_lock)
{
xfs_ail_entry_t *ailp;
xfs_log_item_t *dlip=NULL;
xfs_log_item_t *mlip; /* ptr to minimum lip */
ailp = &(mp->m_ail.xa_ail);
mlip = xfs_ail_min(ailp);
mlip = xfs_ail_min(&mp->m_ail);
if (lip->li_flags & XFS_LI_IN_AIL) {
dlip = xfs_ail_delete(ailp, lip);
dlip = xfs_ail_delete(&mp->m_ail, lip);
ASSERT(dlip == lip);
} else {
lip->li_flags |= XFS_LI_IN_AIL;
@ -373,11 +373,11 @@ xfs_trans_update_ail(
lip->li_lsn = lsn;
xfs_ail_insert(ailp, lip);
xfs_ail_insert(&mp->m_ail, lip);
mp->m_ail.xa_gen++;
if (mlip == dlip) {
mlip = xfs_ail_min(&(mp->m_ail.xa_ail));
mlip = xfs_ail_min(&mp->m_ail);
spin_unlock(&mp->m_ail_lock);
xfs_log_move_tail(mp, mlip->li_lsn);
} else {
@ -407,14 +407,12 @@ xfs_trans_delete_ail(
xfs_mount_t *mp,
xfs_log_item_t *lip) __releases(mp->m_ail_lock)
{
xfs_ail_entry_t *ailp;
xfs_log_item_t *dlip;
xfs_log_item_t *mlip;
if (lip->li_flags & XFS_LI_IN_AIL) {
ailp = &(mp->m_ail.xa_ail);
mlip = xfs_ail_min(ailp);
dlip = xfs_ail_delete(ailp, lip);
mlip = xfs_ail_min(&mp->m_ail);
dlip = xfs_ail_delete(&mp->m_ail, lip);
ASSERT(dlip == lip);
@ -423,7 +421,7 @@ xfs_trans_delete_ail(
mp->m_ail.xa_gen++;
if (mlip == dlip) {
mlip = xfs_ail_min(&(mp->m_ail.xa_ail));
mlip = xfs_ail_min(&mp->m_ail);
spin_unlock(&mp->m_ail_lock);
xfs_log_move_tail(mp, (mlip ? mlip->li_lsn : 0));
} else {
@ -461,7 +459,7 @@ xfs_trans_first_ail(
{
xfs_log_item_t *lip;
lip = xfs_ail_min(&(mp->m_ail.xa_ail));
lip = xfs_ail_min(&mp->m_ail);
*gen = (int)mp->m_ail.xa_gen;
return lip;
@ -485,9 +483,9 @@ xfs_trans_next_ail(
ASSERT(mp && lip && gen);
if (mp->m_ail.xa_gen == *gen) {
nlip = xfs_ail_next(&(mp->m_ail.xa_ail), lip);
nlip = xfs_ail_next(&mp->m_ail, lip);
} else {
nlip = xfs_ail_min(&(mp->m_ail).xa_ail);
nlip = xfs_ail_min(&mp->m_ail);
*gen = (int)mp->m_ail.xa_gen;
if (restarts != NULL) {
XFS_STATS_INC(xs_push_ail_restarts);
@ -517,8 +515,7 @@ int
xfs_trans_ail_init(
xfs_mount_t *mp)
{
mp->m_ail.xa_ail.ail_forw = (xfs_log_item_t*)&mp->m_ail.xa_ail;
mp->m_ail.xa_ail.ail_back = (xfs_log_item_t*)&mp->m_ail.xa_ail;
INIT_LIST_HEAD(&mp->m_ail.xa_ail);
return xfsaild_start(mp);
}
@ -537,7 +534,7 @@ xfs_trans_ail_destroy(
*/
STATIC void
xfs_ail_insert(
xfs_ail_entry_t *base,
xfs_ail_t *ailp,
xfs_log_item_t *lip)
/* ARGSUSED */
{
@ -546,27 +543,22 @@ xfs_ail_insert(
/*
* If the list is empty, just insert the item.
*/
if (base->ail_back == (xfs_log_item_t*)base) {
base->ail_forw = lip;
base->ail_back = lip;
lip->li_ail.ail_forw = (xfs_log_item_t*)base;
lip->li_ail.ail_back = (xfs_log_item_t*)base;
if (list_empty(&ailp->xa_ail)) {
list_add(&lip->li_ail, &ailp->xa_ail);
return;
}
next_lip = base->ail_back;
while ((next_lip != (xfs_log_item_t*)base) &&
(XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) > 0)) {
next_lip = next_lip->li_ail.ail_back;
list_for_each_entry_reverse(next_lip, &ailp->xa_ail, li_ail) {
if (XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0)
break;
}
ASSERT((next_lip == (xfs_log_item_t*)base) ||
(XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0));
lip->li_ail.ail_forw = next_lip->li_ail.ail_forw;
lip->li_ail.ail_back = next_lip;
next_lip->li_ail.ail_forw = lip;
lip->li_ail.ail_forw->li_ail.ail_back = lip;
xfs_ail_check(base, lip);
ASSERT((&next_lip->li_ail == &ailp->xa_ail) ||
(XFS_LSN_CMP(next_lip->li_lsn, lip->li_lsn) <= 0));
list_add(&lip->li_ail, &next_lip->li_ail);
xfs_ail_check(ailp, lip);
return;
}
@ -576,15 +568,13 @@ xfs_ail_insert(
/*ARGSUSED*/
STATIC xfs_log_item_t *
xfs_ail_delete(
xfs_ail_entry_t *base,
xfs_ail_t *ailp,
xfs_log_item_t *lip)
/* ARGSUSED */
{
xfs_ail_check(base, lip);
lip->li_ail.ail_forw->li_ail.ail_back = lip->li_ail.ail_back;
lip->li_ail.ail_back->li_ail.ail_forw = lip->li_ail.ail_forw;
lip->li_ail.ail_forw = NULL;
lip->li_ail.ail_back = NULL;
xfs_ail_check(ailp, lip);
list_del(&lip->li_ail);
return lip;
}
@ -595,14 +585,13 @@ xfs_ail_delete(
*/
STATIC xfs_log_item_t *
xfs_ail_min(
xfs_ail_entry_t *base)
xfs_ail_t *ailp)
/* ARGSUSED */
{
register xfs_log_item_t *forw = base->ail_forw;
if (forw == (xfs_log_item_t*)base) {
if (list_empty(&ailp->xa_ail))
return NULL;
}
return forw;
return list_first_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
}
/*
@ -612,15 +601,14 @@ xfs_ail_min(
*/
STATIC xfs_log_item_t *
xfs_ail_next(
xfs_ail_entry_t *base,
xfs_ail_t *ailp,
xfs_log_item_t *lip)
/* ARGSUSED */
{
if (lip->li_ail.ail_forw == (xfs_log_item_t*)base) {
if (lip->li_ail.next == &ailp->xa_ail)
return NULL;
}
return lip->li_ail.ail_forw;
return list_first_entry(&lip->li_ail, xfs_log_item_t, li_ail);
}
#ifdef DEBUG
@ -629,57 +617,40 @@ xfs_ail_next(
*/
STATIC void
xfs_ail_check(
xfs_ail_entry_t *base,
xfs_ail_t *ailp,
xfs_log_item_t *lip)
{
xfs_log_item_t *prev_lip;
prev_lip = base->ail_forw;
if (prev_lip == (xfs_log_item_t*)base) {
/*
* Make sure the pointers are correct when the list
* is empty.
*/
ASSERT(base->ail_back == (xfs_log_item_t*)base);
if (list_empty(&ailp->xa_ail))
return;
}
/*
* Check the next and previous entries are valid.
*/
ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
prev_lip = lip->li_ail.ail_back;
if (prev_lip != (xfs_log_item_t*)base) {
ASSERT(prev_lip->li_ail.ail_forw == lip);
prev_lip = list_entry(lip->li_ail.prev, xfs_log_item_t, li_ail);
if (&prev_lip->li_ail != &ailp->xa_ail)
ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
}
prev_lip = lip->li_ail.ail_forw;
if (prev_lip != (xfs_log_item_t*)base) {
ASSERT(prev_lip->li_ail.ail_back == lip);
prev_lip = list_entry(lip->li_ail.next, xfs_log_item_t, li_ail);
if (&prev_lip->li_ail != &ailp->xa_ail)
ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) >= 0);
}
#ifdef XFS_TRANS_DEBUG
/*
* Walk the list checking forward and backward pointers,
* lsn ordering, and that every entry has the XFS_LI_IN_AIL
* flag set. This is really expensive, so only do it when
* specifically debugging the transaction subsystem.
* Walk the list checking lsn ordering, and that every entry has the
* XFS_LI_IN_AIL flag set. This is really expensive, so only do it
* when specifically debugging the transaction subsystem.
*/
prev_lip = (xfs_log_item_t*)base;
while (lip != (xfs_log_item_t*)base) {
if (prev_lip != (xfs_log_item_t*)base) {
ASSERT(prev_lip->li_ail.ail_forw == lip);
prev_lip = list_entry(&ailp->xa_ail, xfs_log_item_t, li_ail);
list_for_each_entry(lip, &ailp->xa_ail, li_ail) {
if (&prev_lip->li_ail != &ailp->xa_ail)
ASSERT(XFS_LSN_CMP(prev_lip->li_lsn, lip->li_lsn) <= 0);
}
ASSERT(lip->li_ail.ail_back == prev_lip);
ASSERT((lip->li_flags & XFS_LI_IN_AIL) != 0);
prev_lip = lip;
lip = lip->li_ail.ail_forw;
}
ASSERT(lip == (xfs_log_item_t*)base);
ASSERT(base->ail_back == prev_lip);
#endif /* XFS_TRANS_DEBUG */
}
#endif /* DEBUG */