/*
 * xfs sync routine for internal use
 *
 * This routine supports all of the flags defined for the generic VFS_SYNC
 * interface as explained above under xfs_sync.  In the interests of not
 * changing interfaces within the 6.5 family, additional internallly-
 * required functions are specified within a separate xflags parameter,
 * only available by calling this routine.
 *
 */
int
xfs_syncsub(
	xfs_mount_t	*mp,
	int		flags,
	int             xflags,
	int             *bypassed)
{
	int		error = 0;
	int		last_error = 0;
	uint		log_flags = XFS_LOG_FORCE;
	xfs_buf_t	*bp;
	xfs_buf_log_item_t	*bip;

	/*
	 * Sync out the log.  This ensures that the log is periodically
	 * flushed even if there is not enough activity to fill it up.
	 */
	if (flags & SYNC_WAIT)
		log_flags |= XFS_LOG_SYNC;

	xfs_log_force(mp, (xfs_lsn_t)0, log_flags);

	if (flags & (SYNC_ATTR|SYNC_DELWRI)) {
		if (flags & SYNC_BDFLUSH)
			xfs_finish_reclaim_all(mp, 1);
		else
			error = xfs_sync_inodes(mp, flags, xflags, bypassed);
	}

	/*
	 * Flushing out dirty data above probably generated more
	 * log activity, so if this isn't vfs_sync() then flush
	 * the log again.
	 */
	if (flags & SYNC_DELWRI) {
		xfs_log_force(mp, (xfs_lsn_t)0, log_flags);
	}

	if (flags & SYNC_FSDATA) {
		/*
		 * If this is vfs_sync() then only sync the superblock
		 * if we can lock it without sleeping and it is not pinned.
		 */
		if (flags & SYNC_BDFLUSH) {
			bp = xfs_getsb(mp, XFS_BUF_TRYLOCK);
			if (bp != NULL) {
				bip = XFS_BUF_FSPRIVATE(bp,xfs_buf_log_item_t*);
				if ((bip != NULL) &&
				    xfs_buf_item_dirty(bip)) {
					if (!(XFS_BUF_ISPINNED(bp))) {
						XFS_BUF_ASYNC(bp);
						error = xfs_bwrite(mp, bp);
					} else {
						xfs_buf_relse(bp);
					}
				} else {
					xfs_buf_relse(bp);
				}
			}
		} else {
STATIC int
xfs_sync_fsdata(
	struct xfs_mount	*mp)
{
	struct xfs_buf		*bp;
	int			error;

	bp = xfs_getsb(mp, 0);
	if (xfs_buf_ispinned(bp))
		xfs_log_force(mp, 0);
	error = xfs_bwrite(bp);
	xfs_buf_relse(bp);
	return error;
}
STATIC int
xfs_sync_fsdata(
	struct xfs_mount	*mp)
{
	struct xfs_buf		*bp;

	/*
	 * If the buffer is pinned then push on the log so we won't get stuck
	 * waiting in the write for someone, maybe ourselves, to flush the log.
	 *
	 * Even though we just pushed the log above, we did not have the
	 * superblock buffer locked at that point so it can become pinned in
	 * between there and here.
	 */
	bp = xfs_getsb(mp, 0);
	if (XFS_BUF_ISPINNED(bp))
		xfs_log_force(mp, 0);

	return xfs_bwrite(mp, bp);
}
Exemple #4
0
/*
 * Purge a dquot from all tracking data structures and free it.
 */
STATIC int
xfs_qm_dqpurge(
	struct xfs_dquot	*dqp,
	void			*data)
{
	struct xfs_mount	*mp = dqp->q_mount;
	struct xfs_quotainfo	*qi = mp->m_quotainfo;
	struct xfs_dquot	*gdqp = NULL;

	xfs_dqlock(dqp);
	if ((dqp->dq_flags & XFS_DQ_FREEING) || dqp->q_nrefs != 0) {
		xfs_dqunlock(dqp);
		return EAGAIN;
	}

	/*
	 * If this quota has a group hint attached, prepare for releasing it
	 * now.
	 */
	gdqp = dqp->q_gdquot;
	if (gdqp) {
		xfs_dqlock(gdqp);
		dqp->q_gdquot = NULL;
	}

	dqp->dq_flags |= XFS_DQ_FREEING;

	xfs_dqflock(dqp);

	/*
	 * If we are turning this type of quotas off, we don't care
	 * about the dirty metadata sitting in this dquot. OTOH, if
	 * we're unmounting, we do care, so we flush it and wait.
	 */
	if (XFS_DQ_IS_DIRTY(dqp)) {
		struct xfs_buf	*bp = NULL;
		int		error;

		/*
		 * We don't care about getting disk errors here. We need
		 * to purge this dquot anyway, so we go ahead regardless.
		 */
		error = xfs_qm_dqflush(dqp, &bp);
		if (error) {
			xfs_warn(mp, "%s: dquot %p flush failed",
				__func__, dqp);
		} else {
			error = xfs_bwrite(bp);
			xfs_buf_relse(bp);
		}
		xfs_dqflock(dqp);
	}

	ASSERT(atomic_read(&dqp->q_pincount) == 0);
	ASSERT(XFS_FORCED_SHUTDOWN(mp) ||
	       !(dqp->q_logitem.qli_item.li_flags & XFS_LI_IN_AIL));

	xfs_dqfunlock(dqp);
	xfs_dqunlock(dqp);

	radix_tree_delete(XFS_DQUOT_TREE(qi, dqp->q_core.d_flags),
			  be32_to_cpu(dqp->q_core.d_id));
	qi->qi_dquots--;

	/*
	 * We move dquots to the freelist as soon as their reference count
	 * hits zero, so it really should be on the freelist here.
	 */
	mutex_lock(&qi->qi_lru_lock);
	ASSERT(!list_empty(&dqp->q_lru));
	list_del_init(&dqp->q_lru);
	qi->qi_lru_count--;
	XFS_STATS_DEC(xs_qm_dquot_unused);
	mutex_unlock(&qi->qi_lru_lock);

	xfs_qm_dqdestroy(dqp);

	if (gdqp)
		xfs_qm_dqput(gdqp);
	return 0;
}
/*
 * 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);

}
Exemple #6
0
/*
 * Inodes in different states need to be treated differently. The following
 * table lists the inode states and the reclaim actions necessary:
 *
 *	inode state	     iflush ret		required action
 *      ---------------      ----------         ---------------
 *	bad			-		reclaim
 *	shutdown		EIO		unpin and reclaim
 *	clean, unpinned		0		reclaim
 *	stale, unpinned		0		reclaim
 *	clean, pinned(*)	0		requeue
 *	stale, pinned		EAGAIN		requeue
 *	dirty, async		-		requeue
 *	dirty, sync		0		reclaim
 *
 * (*) dgc: I don't think the clean, pinned state is possible but it gets
 * handled anyway given the order of checks implemented.
 *
 * Also, because we get the flush lock first, we know that any inode that has
 * been flushed delwri has had the flush completed by the time we check that
 * the inode is clean.
 *
 * Note that because the inode is flushed delayed write by AIL pushing, the
 * flush lock may already be held here and waiting on it can result in very
 * long latencies.  Hence for sync reclaims, where we wait on the flush lock,
 * the caller should push the AIL first before trying to reclaim inodes to
 * minimise the amount of time spent waiting.  For background relaim, we only
 * bother to reclaim clean inodes anyway.
 *
 * Hence the order of actions after gaining the locks should be:
 *	bad		=> reclaim
 *	shutdown	=> unpin and reclaim
 *	pinned, async	=> requeue
 *	pinned, sync	=> unpin
 *	stale		=> reclaim
 *	clean		=> reclaim
 *	dirty, async	=> requeue
 *	dirty, sync	=> flush, wait and reclaim
 */
STATIC int
xfs_reclaim_inode(
	struct xfs_inode	*ip,
	struct xfs_perag	*pag,
	int			sync_mode)
{
	struct xfs_buf		*bp = NULL;
	xfs_ino_t		ino = ip->i_ino; /* for radix_tree_delete */
	int			error;

restart:
	error = 0;
	xfs_ilock(ip, XFS_ILOCK_EXCL);
	if (!xfs_iflock_nowait(ip)) {
		if (!(sync_mode & SYNC_WAIT))
			goto out;
		xfs_iflock(ip);
	}

	if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
		xfs_iunpin_wait(ip);
		/* xfs_iflush_abort() drops the flush lock */
		xfs_iflush_abort(ip, false);
		goto reclaim;
	}
	if (xfs_ipincount(ip)) {
		if (!(sync_mode & SYNC_WAIT))
			goto out_ifunlock;
		xfs_iunpin_wait(ip);
	}
	if (xfs_iflags_test(ip, XFS_ISTALE) || xfs_inode_clean(ip)) {
		xfs_ifunlock(ip);
		goto reclaim;
	}

	/*
	 * Never flush out dirty data during non-blocking reclaim, as it would
	 * just contend with AIL pushing trying to do the same job.
	 */
	if (!(sync_mode & SYNC_WAIT))
		goto out_ifunlock;

	/*
	 * Now we have an inode that needs flushing.
	 *
	 * Note that xfs_iflush will never block on the inode buffer lock, as
	 * xfs_ifree_cluster() can lock the inode buffer before it locks the
	 * ip->i_lock, and we are doing the exact opposite here.  As a result,
	 * doing a blocking xfs_imap_to_bp() to get the cluster buffer would
	 * result in an ABBA deadlock with xfs_ifree_cluster().
	 *
	 * As xfs_ifree_cluser() must gather all inodes that are active in the
	 * cache to mark them stale, if we hit this case we don't actually want
	 * to do IO here - we want the inode marked stale so we can simply
	 * reclaim it.  Hence if we get an EAGAIN error here,  just unlock the
	 * inode, back off and try again.  Hopefully the next pass through will
	 * see the stale flag set on the inode.
	 */
	error = xfs_iflush(ip, &bp);
	if (error == -EAGAIN) {
		xfs_iunlock(ip, XFS_ILOCK_EXCL);
		/* backoff longer than in xfs_ifree_cluster */
		delay(2);
		goto restart;
	}

	if (!error) {
		error = xfs_bwrite(bp);
		xfs_buf_relse(bp);
	}

reclaim:
	ASSERT(!xfs_isiflocked(ip));

	/*
	 * Because we use RCU freeing we need to ensure the inode always appears
	 * to be reclaimed with an invalid inode number when in the free state.
	 * We do this as early as possible under the ILOCK so that
	 * xfs_iflush_cluster() can be guaranteed to detect races with us here.
	 * By doing this, we guarantee that once xfs_iflush_cluster has locked
	 * XFS_ILOCK that it will see either a valid, flushable inode that will
	 * serialise correctly, or it will see a clean (and invalid) inode that
	 * it can skip.
	 */
	spin_lock(&ip->i_flags_lock);
	ip->i_flags = XFS_IRECLAIM;
	ip->i_ino = 0;
	spin_unlock(&ip->i_flags_lock);

	xfs_iunlock(ip, XFS_ILOCK_EXCL);

	XFS_STATS_INC(ip->i_mount, xs_ig_reclaims);
	/*
	 * Remove the inode from the per-AG radix tree.
	 *
	 * Because radix_tree_delete won't complain even if the item was never
	 * added to the tree assert that it's been there before to catch
	 * problems with the inode life time early on.
	 */
	spin_lock(&pag->pag_ici_lock);
	if (!radix_tree_delete(&pag->pag_ici_root,
				XFS_INO_TO_AGINO(ip->i_mount, ino)))
		ASSERT(0);
	xfs_perag_clear_reclaim_tag(pag);
	spin_unlock(&pag->pag_ici_lock);

	/*
	 * Here we do an (almost) spurious inode lock in order to coordinate
	 * with inode cache radix tree lookups.  This is because the lookup
	 * can reference the inodes in the cache without taking references.
	 *
	 * We make that OK here by ensuring that we wait until the inode is
	 * unlocked after the lookup before we go ahead and free it.
	 */
	xfs_ilock(ip, XFS_ILOCK_EXCL);
	xfs_qm_dqdetach(ip);
	xfs_iunlock(ip, XFS_ILOCK_EXCL);

	__xfs_inode_free(ip);
	return error;

out_ifunlock:
	xfs_ifunlock(ip);
out:
	xfs_iflags_clear(ip, XFS_IRECLAIM);
	xfs_iunlock(ip, XFS_ILOCK_EXCL);
	/*
	 * We could return -EAGAIN here to make reclaim rescan the inode tree in
	 * a short while. However, this just burns CPU time scanning the tree
	 * waiting for IO to complete and the reclaim work never goes back to
	 * the idle state. Instead, return 0 to let the next scheduled
	 * background reclaim attempt to reclaim the inode again.
	 */
	return 0;
}
/*
 * 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)
{
	struct xfs_mount	*mp = dqp->q_mount;
	struct xfs_buf		*bp;
	struct xfs_disk_dquot	*ddqp;
	int			error;

	ASSERT(XFS_DQ_IS_LOCKED(dqp));
	ASSERT(!completion_done(&dqp->q_flush));

	trace_xfs_dqflush(dqp);

	/*
	 * If not dirty, or it's pinned and we are not supposed to block, nada.
	 */
	if (!XFS_DQ_IS_DIRTY(dqp) ||
	    ((flags & SYNC_TRYLOCK) && atomic_read(&dqp->q_pincount) > 0)) {
		xfs_dqfunlock(dqp);
		return 0;
	}
	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(mp)) {
		dqp->dq_flags &= ~XFS_DQ_DIRTY;
		xfs_dqfunlock(dqp);
		return XFS_ERROR(EIO);
	}

	/*
	 * Get the buffer containing the on-disk dquot
	 */
	error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, dqp->q_blkno,
				   mp->m_quotainfo->qi_dqchunklen, 0, &bp);
	if (error) {
		ASSERT(error != ENOENT);
		xfs_dqfunlock(dqp);
		return error;
	}

	/*
	 * Calculate the location of the dquot inside the buffer.
	 */
	ddqp = bp->b_addr + dqp->q_bufoffset;

	/*
	 * A simple sanity check in case we got a corrupted dquot..
	 */
	error = xfs_qm_dqcheck(mp, &dqp->q_core, be32_to_cpu(ddqp->d_id), 0,
			   XFS_QMOPT_DOWARN, "dqflush (incore copy)");
	if (error) {
		xfs_buf_relse(bp);
		xfs_dqfunlock(dqp);
		xfs_force_shutdown(mp, SHUTDOWN_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;

	xfs_trans_ail_copy_lsn(mp->m_ail, &dqp->q_logitem.qli_flush_lsn,
					&dqp->q_logitem.qli_item.li_lsn);

	/*
	 * 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, 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)) {
		trace_xfs_dqflush_force(dqp);
		xfs_log_force(mp, 0);
	}

	if (flags & SYNC_WAIT)
		error = xfs_bwrite(bp);
	else
		xfs_buf_delwri_queue(bp);

	xfs_buf_relse(bp);

	trace_xfs_dqflush_done(dqp);

	/*
	 * dqp is still locked, but caller is free to unlock it now.
	 */
	return error;

}
Exemple #8
0
/*
 * Write the value associated with an attribute into the out-of-line buffer
 * that we have defined for it.
 */
int
xfs_attr_rmtval_set(
	struct xfs_da_args	*args)
{
	struct xfs_inode	*dp = args->dp;
	struct xfs_mount	*mp = dp->i_mount;
	struct xfs_bmbt_irec	map;
	xfs_dablk_t		lblkno;
	xfs_fileoff_t		lfileoff = 0;
	__uint8_t		*src = args->value;
	int			blkcnt;
	int			valuelen;
	int			nmap;
	int			error;
	int			offset = 0;

	trace_xfs_attr_rmtval_set(args);

	/*
	 * Find a "hole" in the attribute address space large enough for
	 * us to drop the new attribute's value into. Because CRC enable
	 * attributes have headers, we can't just do a straight byte to FSB
	 * conversion and have to take the header space into account.
	 */
	blkcnt = xfs_attr3_rmt_blocks(mp, args->rmtvaluelen);
	error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
						   XFS_ATTR_FORK);
	if (error)
		return error;

	args->rmtblkno = lblkno = (xfs_dablk_t)lfileoff;
	args->rmtblkcnt = blkcnt;

	/*
	 * Roll through the "value", allocating blocks on disk as required.
	 */
	while (blkcnt > 0) {
		int	committed;

		/*
		 * Allocate a single extent, up to the size of the value.
		 */
		xfs_bmap_init(args->flist, args->firstblock);
		nmap = 1;
		error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno,
				  blkcnt,
				  XFS_BMAPI_ATTRFORK | XFS_BMAPI_METADATA,
				  args->firstblock, args->total, &map, &nmap,
				  args->flist);
		if (!error) {
			error = xfs_bmap_finish(&args->trans, args->flist,
						&committed);
		}
		if (error) {
			ASSERT(committed);
			args->trans = NULL;
			xfs_bmap_cancel(args->flist);
			return error;
		}

		/*
		 * bmap_finish() may have committed the last trans and started
		 * a new one.  We need the inode to be in all transactions.
		 */
		if (committed)
			xfs_trans_ijoin(args->trans, dp, 0);

		ASSERT(nmap == 1);
		ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
		       (map.br_startblock != HOLESTARTBLOCK));
		lblkno += map.br_blockcount;
		blkcnt -= map.br_blockcount;

		/*
		 * Start the next trans in the chain.
		 */
		error = xfs_trans_roll(&args->trans, dp);
		if (error)
			return error;
	}

	/*
	 * Roll through the "value", copying the attribute value to the
	 * already-allocated blocks.  Blocks are written synchronously
	 * so that we can know they are all on disk before we turn off
	 * the INCOMPLETE flag.
	 */
	lblkno = args->rmtblkno;
	blkcnt = args->rmtblkcnt;
	valuelen = args->rmtvaluelen;
	while (valuelen > 0) {
		struct xfs_buf	*bp;
		xfs_daddr_t	dblkno;
		int		dblkcnt;

		ASSERT(blkcnt > 0);

		xfs_bmap_init(args->flist, args->firstblock);
		nmap = 1;
		error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
				       blkcnt, &map, &nmap,
				       XFS_BMAPI_ATTRFORK);
		if (error)
			return error;
		ASSERT(nmap == 1);
		ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
		       (map.br_startblock != HOLESTARTBLOCK));

		dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
		dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);

		bp = xfs_buf_get(mp->m_ddev_targp, dblkno, dblkcnt, 0);
		if (!bp)
			return -ENOMEM;
		bp->b_ops = &xfs_attr3_rmt_buf_ops;

		xfs_attr_rmtval_copyin(mp, bp, args->dp->i_ino, &offset,
				       &valuelen, &src);

		error = xfs_bwrite(bp);	/* GROT: NOTE: synchronous write */
		xfs_buf_relse(bp);
		if (error)
			return error;


		/* roll attribute extent map forwards */
		lblkno += map.br_blockcount;
		blkcnt -= map.br_blockcount;
	}
	ASSERT(valuelen == 0);
	return 0;
}
Exemple #9
0
/*
 * Write the value associated with an attribute into the out-of-line buffer
 * that we have defined for it.
 */
int
xfs_attr_rmtval_set(
	struct xfs_da_args	*args)
{
	struct xfs_inode	*dp = args->dp;
	struct xfs_mount	*mp = dp->i_mount;
	struct xfs_bmbt_irec	map;
	xfs_dablk_t		lblkno;
	xfs_fileoff_t		lfileoff = 0;
	uint8_t			*src = args->value;
	int			blkcnt;
	int			valuelen;
	int			nmap;
	int			error;
	int			offset = 0;

	trace_xfs_attr_rmtval_set(args);

	/*
	 * Find a "hole" in the attribute address space large enough for
	 * us to drop the new attribute's value into. Because CRC enable
	 * attributes have headers, we can't just do a straight byte to FSB
	 * conversion and have to take the header space into account.
	 */
	blkcnt = xfs_attr3_rmt_blocks(mp, args->rmtvaluelen);
	error = xfs_bmap_first_unused(args->trans, args->dp, blkcnt, &lfileoff,
						   XFS_ATTR_FORK);
	if (error)
		return error;

	args->rmtblkno = lblkno = (xfs_dablk_t)lfileoff;
	args->rmtblkcnt = blkcnt;

	/*
	 * Roll through the "value", allocating blocks on disk as required.
	 */
	while (blkcnt > 0) {
		/*
		 * Allocate a single extent, up to the size of the value.
		 *
		 * Note that we have to consider this a data allocation as we
		 * write the remote attribute without logging the contents.
		 * Hence we must ensure that we aren't using blocks that are on
		 * the busy list so that we don't overwrite blocks which have
		 * recently been freed but their transactions are not yet
		 * committed to disk. If we overwrite the contents of a busy
		 * extent and then crash then the block may not contain the
		 * correct metadata after log recovery occurs.
		 */
		xfs_defer_init(args->dfops, args->firstblock);
		nmap = 1;
		error = xfs_bmapi_write(args->trans, dp, (xfs_fileoff_t)lblkno,
				  blkcnt, XFS_BMAPI_ATTRFORK, args->firstblock,
				  args->total, &map, &nmap, args->dfops);
		if (!error)
			error = xfs_defer_finish(&args->trans, args->dfops, dp);
		if (error) {
			args->trans = NULL;
			xfs_defer_cancel(args->dfops);
			return error;
		}

		ASSERT(nmap == 1);
		ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
		       (map.br_startblock != HOLESTARTBLOCK));
		lblkno += map.br_blockcount;
		blkcnt -= map.br_blockcount;

		/*
		 * Start the next trans in the chain.
		 */
		error = xfs_trans_roll(&args->trans, dp);
		if (error)
			return error;
	}

	/*
	 * Roll through the "value", copying the attribute value to the
	 * already-allocated blocks.  Blocks are written synchronously
	 * so that we can know they are all on disk before we turn off
	 * the INCOMPLETE flag.
	 */
	lblkno = args->rmtblkno;
	blkcnt = args->rmtblkcnt;
	valuelen = args->rmtvaluelen;
	while (valuelen > 0) {
		struct xfs_buf	*bp;
		xfs_daddr_t	dblkno;
		int		dblkcnt;

		ASSERT(blkcnt > 0);

		xfs_defer_init(args->dfops, args->firstblock);
		nmap = 1;
		error = xfs_bmapi_read(dp, (xfs_fileoff_t)lblkno,
				       blkcnt, &map, &nmap,
				       XFS_BMAPI_ATTRFORK);
		if (error)
			return error;
		ASSERT(nmap == 1);
		ASSERT((map.br_startblock != DELAYSTARTBLOCK) &&
		       (map.br_startblock != HOLESTARTBLOCK));

		dblkno = XFS_FSB_TO_DADDR(mp, map.br_startblock),
		dblkcnt = XFS_FSB_TO_BB(mp, map.br_blockcount);

		bp = xfs_buf_get(mp->m_ddev_targp, dblkno, dblkcnt, 0);
		if (!bp)
			return -ENOMEM;
		bp->b_ops = &xfs_attr3_rmt_buf_ops;

		xfs_attr_rmtval_copyin(mp, bp, args->dp->i_ino, &offset,
				       &valuelen, &src);

		error = xfs_bwrite(bp);	/* GROT: NOTE: synchronous write */
		xfs_buf_relse(bp);
		if (error)
			return error;


		/* roll attribute extent map forwards */
		lblkno += map.br_blockcount;
		blkcnt -= map.br_blockcount;
	}
	ASSERT(valuelen == 0);
	return 0;
}