[19/27] xfs: force the log if we encounter pinned buffers in .iop_pushbuf

From: Greg KH
Date: Sun Oct 23 2011 - 02:38:55 EST


3.0-stable review patch. If anyone has any objections, please let us know.

------------------

From: Christoph Hellwig <hch@xxxxxxxxxxxxx>

commit 17b38471c3c07a49f0bbc2ecc2e92050c164e226 upstream

We need to check for pinned buffers even in .iop_pushbuf given that inode
items flush into the same buffers that may be pinned directly due operations
on the unlinked inode list operating directly on buffers. To do this add a
return value to .iop_pushbuf that tells the AIL push about this and use
the existing log force mechanisms to unpin it.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reported-by: Stefan Priebe <s.priebe@xxxxxxxxxxxx>
Tested-by: Stefan Priebe <s.priebe@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

---
fs/xfs/quota/xfs_dquot_item.c | 10 +++++++---
fs/xfs/xfs_buf_item.c | 3 ++-
fs/xfs/xfs_inode_item.c | 10 +++++++---
fs/xfs/xfs_trans.h | 2 +-
fs/xfs/xfs_trans_ail.c | 9 +++++++--
5 files changed, 24 insertions(+), 10 deletions(-)

--- a/fs/xfs/quota/xfs_dquot_item.c
+++ b/fs/xfs/quota/xfs_dquot_item.c
@@ -183,13 +183,14 @@ xfs_qm_dqunpin_wait(
* search the buffer cache can be a time consuming thing, and AIL lock is a
* spinlock.
*/
-STATIC void
+STATIC bool
xfs_qm_dquot_logitem_pushbuf(
struct xfs_log_item *lip)
{
struct xfs_dq_logitem *qlip = DQUOT_ITEM(lip);
struct xfs_dquot *dqp = qlip->qli_dquot;
struct xfs_buf *bp;
+ bool ret = true;

ASSERT(XFS_DQ_IS_LOCKED(dqp));

@@ -201,17 +202,20 @@ xfs_qm_dquot_logitem_pushbuf(
if (completion_done(&dqp->q_flush) ||
!(lip->li_flags & XFS_LI_IN_AIL)) {
xfs_dqunlock(dqp);
- return;
+ return true;
}

bp = xfs_incore(dqp->q_mount->m_ddev_targp, qlip->qli_format.qlf_blkno,
dqp->q_mount->m_quotainfo->qi_dqchunklen, XBF_TRYLOCK);
xfs_dqunlock(dqp);
if (!bp)
- return;
+ return true;
if (XFS_BUF_ISDELAYWRITE(bp))
xfs_buf_delwri_promote(bp);
+ if (XFS_BUF_ISPINNED(bp))
+ ret = false;
xfs_buf_relse(bp);
+ return ret;
}

/*
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -632,7 +632,7 @@ xfs_buf_item_push(
* the xfsbufd to get this buffer written. We have to unlock the buffer
* to allow the xfsbufd to write it, too.
*/
-STATIC void
+STATIC bool
xfs_buf_item_pushbuf(
struct xfs_log_item *lip)
{
@@ -646,6 +646,7 @@ xfs_buf_item_pushbuf(

xfs_buf_delwri_promote(bp);
xfs_buf_relse(bp);
+ return true;
}

STATIC void
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -713,13 +713,14 @@ xfs_inode_item_committed(
* marked delayed write. If that's the case, we'll promote it and that will
* allow the caller to write the buffer by triggering the xfsbufd to run.
*/
-STATIC void
+STATIC bool
xfs_inode_item_pushbuf(
struct xfs_log_item *lip)
{
struct xfs_inode_log_item *iip = INODE_ITEM(lip);
struct xfs_inode *ip = iip->ili_inode;
struct xfs_buf *bp;
+ bool ret = true;

ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED));

@@ -730,7 +731,7 @@ xfs_inode_item_pushbuf(
if (completion_done(&ip->i_flush) ||
!(lip->li_flags & XFS_LI_IN_AIL)) {
xfs_iunlock(ip, XFS_ILOCK_SHARED);
- return;
+ return true;
}

bp = xfs_incore(ip->i_mount->m_ddev_targp, iip->ili_format.ilf_blkno,
@@ -738,10 +739,13 @@ xfs_inode_item_pushbuf(

xfs_iunlock(ip, XFS_ILOCK_SHARED);
if (!bp)
- return;
+ return true;
if (XFS_BUF_ISDELAYWRITE(bp))
xfs_buf_delwri_promote(bp);
+ if (XFS_BUF_ISPINNED(bp))
+ ret = false;
xfs_buf_relse(bp);
+ return ret;
}

/*
--- a/fs/xfs/xfs_trans.h
+++ b/fs/xfs/xfs_trans.h
@@ -350,7 +350,7 @@ typedef struct xfs_item_ops {
void (*iop_unlock)(xfs_log_item_t *);
xfs_lsn_t (*iop_committed)(xfs_log_item_t *, xfs_lsn_t);
void (*iop_push)(xfs_log_item_t *);
- void (*iop_pushbuf)(xfs_log_item_t *);
+ bool (*iop_pushbuf)(xfs_log_item_t *);
void (*iop_committing)(xfs_log_item_t *, xfs_lsn_t);
} xfs_item_ops_t;

--- a/fs/xfs/xfs_trans_ail.c
+++ b/fs/xfs/xfs_trans_ail.c
@@ -478,8 +478,13 @@ xfs_ail_worker(

case XFS_ITEM_PUSHBUF:
XFS_STATS_INC(xs_push_ail_pushbuf);
- IOP_PUSHBUF(lip);
- ailp->xa_last_pushed_lsn = lsn;
+
+ if (!IOP_PUSHBUF(lip)) {
+ stuck++;
+ flush_log = 1;
+ } else {
+ ailp->xa_last_pushed_lsn = lsn;
+ }
push_xfsbufd = 1;
break;



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