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authorJosef 'Jeff' Sipek <jeffpc@josefsipek.net>2008-03-27 17:58:27 +1100
committerLachlan McIlroy <lachlan@redback.melbourne.sgi.com>2008-04-18 11:41:57 +1000
commit535f6b3735db6ef6026537bfe55ae00c3d9cc1ee (patch)
tree49be6c12a19332a0ce0288143f67b44e4b8538b8
parenta45c796867df8dabc8eed6e72898d7ba1609bd7e (diff)
[XFS] Replace custom AIL linked-list code with struct list_head
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>
-rw-r--r--fs/xfs/xfs_mount.h2
-rw-r--r--fs/xfs/xfs_trans.h7
-rw-r--r--fs/xfs/xfs_trans_ail.c149
3 files changed, 62 insertions, 96 deletions
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 7b37fa00929..77b39f66cea 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -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;
diff --git a/fs/xfs/xfs_trans.h b/fs/xfs/xfs_trans.h
index b5effce0008..0804207c739 100644
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -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 */
diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c
index 76d470d8a1e..13235ae9a58 100644
--- a/fs/xfs/xfs_trans_ail.c
+++ b/fs/xfs/xfs_trans_ail.c
@@ -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) ||
+
+ ASSERT((&next_lip->li_ail == &ailp->xa_ail) ||
(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);
+ 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 */