/*
 * Give the buffer a little push if it is incore and
 * wait on the flush lock.
 */
void
xfs_qm_dqflock_pushbuf_wait(
	xfs_dquot_t	*dqp)
{
	xfs_buf_t	*bp;

	/*
	 * Check to see if the dquot has been flushed delayed
	 * write.  If so, grab its buffer and send it
	 * out immediately.  We'll be able to acquire
	 * the flush lock when the I/O completes.
	 */
	bp = xfs_incore(dqp->q_mount->m_ddev_targp, dqp->q_blkno,
		    XFS_QI_DQCHUNKLEN(dqp->q_mount),
		    XFS_INCORE_TRYLOCK);
	if (bp != NULL) {
		if (XFS_BUF_ISDELAYWRITE(bp)) {
			if (XFS_BUF_ISPINNED(bp)) {
				xfs_log_force(dqp->q_mount,
					      (xfs_lsn_t)0,
					      XFS_LOG_FORCE);
			}
			xfs_bawrite(dqp->q_mount, bp);
		} else {
			xfs_buf_relse(bp);
		}
	}
	xfs_dqflock(dqp);
}
/*
 * Write a modified dquot to disk.
 * The dquot must be locked and the flush lock too taken by caller.
 * The flush lock will not be unlocked until the dquot reaches the disk,
 * but the dquot is free to be unlocked and modified by the caller
 * in the interim. Dquot is still locked on return. This behavior is
 * identical to that of inodes.
 */
int
xfs_qm_dqflush(
	xfs_dquot_t		*dqp,
	uint			flags)
{
	xfs_mount_t		*mp;
	xfs_buf_t		*bp;
	xfs_disk_dquot_t	*ddqp;
	int			error;
	SPLDECL(s);

	ASSERT(XFS_DQ_IS_LOCKED(dqp));
	ASSERT(XFS_DQ_IS_FLUSH_LOCKED(dqp));
	xfs_dqtrace_entry(dqp, "DQFLUSH");

	/*
	 * If not dirty, nada.
	 */
	if (!XFS_DQ_IS_DIRTY(dqp)) {
		xfs_dqfunlock(dqp);
		return (0);
	}

	/*
	 * Cant flush a pinned dquot. Wait for it.
	 */
	xfs_qm_dqunpin_wait(dqp);

	/*
	 * This may have been unpinned because the filesystem is shutting
	 * down forcibly. If that's the case we must not write this dquot
	 * to disk, because the log record didn't make it to disk!
	 */
	if (XFS_FORCED_SHUTDOWN(dqp->q_mount)) {
		dqp->dq_flags &= ~(XFS_DQ_DIRTY);
		xfs_dqfunlock(dqp);
		return XFS_ERROR(EIO);
	}

	/*
	 * Get the buffer containing the on-disk dquot
	 * We don't need a transaction envelope because we know that the
	 * the ondisk-dquot has already been allocated for.
	 */
	if ((error = xfs_qm_dqtobp(NULL, dqp, &ddqp, &bp, XFS_QMOPT_DOWARN))) {
		xfs_dqtrace_entry(dqp, "DQTOBP FAIL");
		ASSERT(error != ENOENT);
		/*
		 * Quotas could have gotten turned off (ESRCH)
		 */
		xfs_dqfunlock(dqp);
		return (error);
	}

	if (xfs_qm_dqcheck(&dqp->q_core, be32_to_cpu(ddqp->d_id),
			   0, XFS_QMOPT_DOWARN, "dqflush (incore copy)")) {
		xfs_force_shutdown(dqp->q_mount, XFS_CORRUPT_INCORE);
		return XFS_ERROR(EIO);
	}

	/* This is the only portion of data that needs to persist */
	memcpy(ddqp, &(dqp->q_core), sizeof(xfs_disk_dquot_t));

	/*
	 * Clear the dirty field and remember the flush lsn for later use.
	 */
	dqp->dq_flags &= ~(XFS_DQ_DIRTY);
	mp = dqp->q_mount;

	/* lsn is 64 bits */
	AIL_LOCK(mp, s);
	dqp->q_logitem.qli_flush_lsn = dqp->q_logitem.qli_item.li_lsn;
	AIL_UNLOCK(mp, s);

	/*
	 * Attach an iodone routine so that we can remove this dquot from the
	 * AIL and release the flush lock once the dquot is synced to disk.
	 */
	xfs_buf_attach_iodone(bp, (void(*)(xfs_buf_t *, xfs_log_item_t *))
			      xfs_qm_dqflush_done, &(dqp->q_logitem.qli_item));
	/*
	 * If the buffer is pinned then push on the log so we won't
	 * get stuck waiting in the write for too long.
	 */
	if (XFS_BUF_ISPINNED(bp)) {
		xfs_dqtrace_entry(dqp, "DQFLUSH LOG FORCE");
		xfs_log_force(mp, (xfs_lsn_t)0, XFS_LOG_FORCE);
	}

	if (flags & XFS_QMOPT_DELWRI) {
		xfs_bdwrite(mp, bp);
	} else if (flags & XFS_QMOPT_ASYNC) {
		xfs_bawrite(mp, bp);
	} else {
		error = xfs_bwrite(mp, bp);
	}
	xfs_dqtrace_entry(dqp, "DQFLUSH END");
	/*
	 * dqp is still locked, but caller is free to unlock it now.
	 */
	return (error);

}
/*
 * This gets called by xfs_trans_push_ail(), when IOP_TRYLOCK
 * failed to get the inode flush lock but did get the inode locked SHARED.
 * Here we're trying to see if the inode buffer is incore, and if so whether it's
 * marked delayed write. If that's the case, we'll initiate a bawrite on that
 * buffer to expedite the process.
 *
 * We aren't holding the AIL lock (or the flush lock) when this gets called,
 * so it is inherently race-y.
 */
STATIC void
xfs_inode_item_pushbuf(
	xfs_inode_log_item_t	*iip)
{
	xfs_inode_t	*ip;
	xfs_mount_t	*mp;
	xfs_buf_t	*bp;
	uint		dopush;

	ip = iip->ili_inode;

	ASSERT(xfs_isilocked(ip, XFS_ILOCK_SHARED));

	/*
	 * The ili_pushbuf_flag keeps others from
	 * trying to duplicate our effort.
	 */
	ASSERT(iip->ili_pushbuf_flag != 0);
	ASSERT(iip->ili_push_owner == current_pid());

	/*
	 * If a flush is not in progress anymore, chances are that the
	 * inode was taken off the AIL. So, just get out.
	 */
	if (completion_done(&ip->i_flush) ||
	    ((iip->ili_item.li_flags & XFS_LI_IN_AIL) == 0)) {
		iip->ili_pushbuf_flag = 0;
		xfs_iunlock(ip, XFS_ILOCK_SHARED);
		return;
	}

	mp = ip->i_mount;
	bp = xfs_incore(mp->m_ddev_targp, iip->ili_format.ilf_blkno,
		    iip->ili_format.ilf_len, XFS_INCORE_TRYLOCK);

	if (bp != NULL) {
		if (XFS_BUF_ISDELAYWRITE(bp)) {
			/*
			 * We were racing with iflush because we don't hold
			 * the AIL lock or the flush lock. However, at this point,
			 * we have the buffer, and we know that it's dirty.
			 * So, it's possible that iflush raced with us, and
			 * this item is already taken off the AIL.
			 * If not, we can flush it async.
			 */
			dopush = ((iip->ili_item.li_flags & XFS_LI_IN_AIL) &&
				  !completion_done(&ip->i_flush));
			iip->ili_pushbuf_flag = 0;
			xfs_iunlock(ip, XFS_ILOCK_SHARED);
			xfs_buftrace("INODE ITEM PUSH", bp);
			if (XFS_BUF_ISPINNED(bp)) {
				xfs_log_force(mp, (xfs_lsn_t)0,
					      XFS_LOG_FORCE);
			}
			if (dopush) {
				int	error;
				error = xfs_bawrite(mp, bp);
				if (error)
					xfs_fs_cmn_err(CE_WARN, mp,
		"xfs_inode_item_pushbuf: pushbuf error %d on iip %p, bp %p",
							error, iip, bp);
			} else {
				xfs_buf_relse(bp);
			}
		} else {
			iip->ili_pushbuf_flag = 0;
			xfs_iunlock(ip, XFS_ILOCK_SHARED);
			xfs_buf_relse(bp);
		}
		return;
	}
	/*
	 * We have to be careful about resetting pushbuf flag too early (above).
	 * Even though in theory we can do it as soon as we have the buflock,
	 * we don't want others to be doing work needlessly. They'll come to
	 * this function thinking that pushing the buffer is their
	 * responsibility only to find that the buffer is still locked by
	 * another doing the same thing
	 */
	iip->ili_pushbuf_flag = 0;
	xfs_iunlock(ip, XFS_ILOCK_SHARED);
	return;
}
Ejemplo n.º 4
0
/*
 * This is called when IOP_TRYLOCK returns XFS_ITEM_PUSHBUF to indicate that
 * the dquot is locked by us, but the flush lock isn't. So, here we are
 * going to see if the relevant dquot buffer is incore, waiting on DELWRI.
 * If so, we want to push it out to help us take this item off the AIL as soon
 * as possible.
 *
 * We must not be holding the AIL lock at this point. Calling incore() to
 * search the buffer cache can be a time consuming thing, and AIL lock is a
 * spinlock.
 */
STATIC void
xfs_qm_dquot_logitem_pushbuf(
	xfs_dq_logitem_t    *qip)
{
	xfs_dquot_t	*dqp;
	xfs_mount_t	*mp;
	xfs_buf_t	*bp;
	uint		dopush;

	dqp = qip->qli_dquot;
	ASSERT(XFS_DQ_IS_LOCKED(dqp));

	/*
	 * The qli_pushbuf_flag keeps others from
	 * trying to duplicate our effort.
	 */
	ASSERT(qip->qli_pushbuf_flag != 0);
	ASSERT(qip->qli_push_owner == current_pid());

	/*
	 * If flushlock isn't locked anymore, chances are that the
	 * inode flush completed and the inode was taken off the AIL.
	 * So, just get out.
	 */
	if (!issemalocked(&(dqp->q_flock))  ||
	    ((qip->qli_item.li_flags & XFS_LI_IN_AIL) == 0)) {
		qip->qli_pushbuf_flag = 0;
		xfs_dqunlock(dqp);
		return;
	}
	mp = dqp->q_mount;
	bp = xfs_incore(mp->m_ddev_targp, qip->qli_format.qlf_blkno,
		    XFS_QI_DQCHUNKLEN(mp),
		    XFS_INCORE_TRYLOCK);
	if (bp != NULL) {
		if (XFS_BUF_ISDELAYWRITE(bp)) {
			dopush = ((qip->qli_item.li_flags & XFS_LI_IN_AIL) &&
				  issemalocked(&(dqp->q_flock)));
			qip->qli_pushbuf_flag = 0;
			xfs_dqunlock(dqp);

			if (XFS_BUF_ISPINNED(bp)) {
				xfs_log_force(mp, (xfs_lsn_t)0,
					      XFS_LOG_FORCE);
			}
			if (dopush) {
				int	error;
#ifdef XFSRACEDEBUG
				delay_for_intr();
				delay(300);
#endif
				error = xfs_bawrite(mp, bp);
				if (error)
					xfs_fs_cmn_err(CE_WARN, mp,
	"xfs_qm_dquot_logitem_pushbuf: pushbuf error %d on qip %p, bp %p",
							error, qip, bp);
			} else {
				xfs_buf_relse(bp);
			}
		} else {
			qip->qli_pushbuf_flag = 0;
			xfs_dqunlock(dqp);
			xfs_buf_relse(bp);
		}
		return;
	}

	qip->qli_pushbuf_flag = 0;
	xfs_dqunlock(dqp);
}
Ejemplo n.º 5
0
/*
 * This gets called by xfs_trans_push_ail(), when IOP_TRYLOCK
 * failed to get the inode flush lock but did get the inode locked SHARED.
 * Here we're trying to see if the inode buffer is incore, and if so whether it's
 * marked delayed write. If that's the case, we'll initiate a bawrite on that
 * buffer to expedite the process.
 *
 * We aren't holding the AIL_LOCK (or the flush lock) when this gets called,
 * so it is inherently race-y.
 */
STATIC void
xfs_inode_item_pushbuf(
	xfs_inode_log_item_t	*iip)
{
	xfs_inode_t	*ip;
	xfs_mount_t 	*mp;
	xfs_buf_t		*bp;
	uint		dopush;

	ip = iip->ili_inode;
	
	ASSERT(ismrlocked(&(ip->i_lock), MR_ACCESS));

	/*
	 * The ili_pushbuf_flag keeps others from
	 * trying to duplicate our effort.
	 */
	ASSERT(iip->ili_pushbuf_flag != 0);
	ASSERT(iip->ili_push_owner == get_thread_id());

	/*
	 * If flushlock isn't locked anymore, chances are that the
	 * inode flush completed and the inode was taken off the AIL.
	 * So, just get out.
	 */
	if ((valusema(&(ip->i_flock)) > 0)  ||
	    ((iip->ili_item.li_flags & XFS_LI_IN_AIL) == 0)) {
		iip->ili_pushbuf_flag = 0;
		xfs_iunlock(ip, XFS_ILOCK_SHARED);
	    	return;
	}
	
	mp = ip->i_mount;
	bp = xfs_incore(mp->m_ddev_targ, iip->ili_format.ilf_blkno,
		    iip->ili_format.ilf_len, XFS_INCORE_TRYLOCK);

	if (bp != NULL) {
		if (XFS_BUF_ISDELAYWRITE(bp)) {
			/*
			 * We were racing with iflush because we don't hold
			 * the AIL_LOCK or the flush lock. However, at this point,
			 * we have the buffer, and we know that it's dirty.
			 * So, it's possible that iflush raced with us, and
			 * this item is already taken off the AIL.
			 * If not, we can flush it async.
			 */
			dopush = ((iip->ili_item.li_flags & XFS_LI_IN_AIL) && 
				  (valusema(&(ip->i_flock)) <= 0));
			iip->ili_pushbuf_flag = 0;
			xfs_iunlock(ip, XFS_ILOCK_SHARED);
			xfs_buftrace("INODE ITEM PUSH", bp);
			if (XFS_BUF_ISPINNED(bp)) {
				xfs_log_force(mp, (xfs_lsn_t)0,
					      XFS_LOG_FORCE);
			}
			if (dopush) {
				xfs_bawrite(mp, bp);
			} else {
				xfs_buf_relse(bp);
			}
		} else {
			iip->ili_pushbuf_flag = 0;
			xfs_iunlock(ip, XFS_ILOCK_SHARED); 
			xfs_buf_relse(bp);
		}
		return;
	}
	/*
	 * We have to be careful about resetting pushbuf flag too early (above).
	 * Eventhough in theory we can do it as soon as we have the buflock,
	 * we don't want others to be doing work needlessly. They'll come to
	 * this function thinking that pushing the buffer is there responsibility
	 * only to find that the buffer is still locked by another doing the
	 * same thing.XXX
	 */
	iip->ili_pushbuf_flag = 0;
	xfs_iunlock(ip, XFS_ILOCK_SHARED); 
	return;
}