1 files changed, 289 insertions, 0 deletions
diff --git a/fs/xfs/libxfs/xfs_dquot_buf.c b/fs/xfs/libxfs/xfs_dquot_buf.c
new file mode 100644
index 000000000..d293f371d
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_dquot_buf.c
@@ -0,0 +1,289 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * Copyright (c) 2013 Red Hat, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_inode.h"
+#include "xfs_quota.h"
+#include "xfs_trans.h"
+#include "xfs_qm.h"
+#include "xfs_error.h"
+#include "xfs_cksum.h"
+#include "xfs_trace.h"
+
+int
+xfs_calc_dquots_per_chunk(
+	unsigned int		nbblks)	/* basic block units */
+{
+	ASSERT(nbblks > 0);
+	return BBTOB(nbblks) / sizeof(xfs_dqblk_t);
+}
+
+/*
+ * Do some primitive error checking on ondisk dquot data structures.
+ *
+ * The xfs_dqblk structure /contains/ the xfs_disk_dquot structure;
+ * we verify them separately because at some points we have only the
+ * smaller xfs_disk_dquot structure available.
+ */
+
+xfs_failaddr_t
+xfs_dquot_verify(
+	struct xfs_mount *mp,
+	xfs_disk_dquot_t *ddq,
+	xfs_dqid_t	 id,
+	uint		 type)	  /* used only during quotacheck */
+{
+	/*
+	 * We can encounter an uninitialized dquot buffer for 2 reasons:
+	 * 1. If we crash while deleting the quotainode(s), and those blks got
+	 *    used for user data. This is because we take the path of regular
+	 *    file deletion; however, the size field of quotainodes is never
+	 *    updated, so all the tricks that we play in itruncate_finish
+	 *    don't quite matter.
+	 *
+	 * 2. We don't play the quota buffers when there's a quotaoff logitem.
+	 *    But the allocation will be replayed so we'll end up with an
+	 *    uninitialized quota block.
+	 *
+	 * This is all fine; things are still consistent, and we haven't lost
+	 * any quota information. Just don't complain about bad dquot blks.
+	 */
+	if (ddq->d_magic != cpu_to_be16(XFS_DQUOT_MAGIC))
+		return __this_address;
+	if (ddq->d_version != XFS_DQUOT_VERSION)
+		return __this_address;
+
+	if (type && ddq->d_flags != type)
+		return __this_address;
+	if (ddq->d_flags != XFS_DQ_USER &&
+	    ddq->d_flags != XFS_DQ_PROJ &&
+	    ddq->d_flags != XFS_DQ_GROUP)
+		return __this_address;
+
+	if (id != -1 && id != be32_to_cpu(ddq->d_id))
+		return __this_address;
+
+	if (!ddq->d_id)
+		return NULL;
+
+	if (ddq->d_blk_softlimit &&
+	    be64_to_cpu(ddq->d_bcount) > be64_to_cpu(ddq->d_blk_softlimit) &&
+	    !ddq->d_btimer)
+		return __this_address;
+
+	if (ddq->d_ino_softlimit &&
+	    be64_to_cpu(ddq->d_icount) > be64_to_cpu(ddq->d_ino_softlimit) &&
+	    !ddq->d_itimer)
+		return __this_address;
+
+	if (ddq->d_rtb_softlimit &&
+	    be64_to_cpu(ddq->d_rtbcount) > be64_to_cpu(ddq->d_rtb_softlimit) &&
+	    !ddq->d_rtbtimer)
+		return __this_address;
+
+	return NULL;
+}
+
+xfs_failaddr_t
+xfs_dqblk_verify(
+	struct xfs_mount	*mp,
+	struct xfs_dqblk	*dqb,
+	xfs_dqid_t	 	id,
+	uint		 	type)	/* used only during quotacheck */
+{
+	if (xfs_sb_version_hascrc(&mp->m_sb) &&
+	    !uuid_equal(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid))
+		return __this_address;
+
+	return xfs_dquot_verify(mp, &dqb->dd_diskdq, id, type);
+}
+
+/*
+ * Do some primitive error checking on ondisk dquot data structures.
+ */
+int
+xfs_dqblk_repair(
+	struct xfs_mount	*mp,
+	struct xfs_dqblk	*dqb,
+	xfs_dqid_t		id,
+	uint			type)
+{
+	/*
+	 * Typically, a repair is only requested by quotacheck.
+	 */
+	ASSERT(id != -1);
+	memset(dqb, 0, sizeof(xfs_dqblk_t));
+
+	dqb->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
+	dqb->dd_diskdq.d_version = XFS_DQUOT_VERSION;
+	dqb->dd_diskdq.d_flags = type;
+	dqb->dd_diskdq.d_id = cpu_to_be32(id);
+
+	if (xfs_sb_version_hascrc(&mp->m_sb)) {
+		uuid_copy(&dqb->dd_uuid, &mp->m_sb.sb_meta_uuid);
+		xfs_update_cksum((char *)dqb, sizeof(struct xfs_dqblk),
+				 XFS_DQUOT_CRC_OFF);
+	}
+
+	return 0;
+}
+
+STATIC bool
+xfs_dquot_buf_verify_crc(
+	struct xfs_mount	*mp,
+	struct xfs_buf		*bp,
+	bool			readahead)
+{
+	struct xfs_dqblk	*d = (struct xfs_dqblk *)bp->b_addr;
+	int			ndquots;
+	int			i;
+
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return true;
+
+	/*
+	 * if we are in log recovery, the quota subsystem has not been
+	 * initialised so we have no quotainfo structure. In that case, we need
+	 * to manually calculate the number of dquots in the buffer.
+	 */
+	if (mp->m_quotainfo)
+		ndquots = mp->m_quotainfo->qi_dqperchunk;
+	else
+		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
+
+	for (i = 0; i < ndquots; i++, d++) {
+		if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
+				 XFS_DQUOT_CRC_OFF)) {
+			if (!readahead)
+				xfs_buf_verifier_error(bp, -EFSBADCRC, __func__,
+					d, sizeof(*d), __this_address);
+			return false;
+		}
+	}
+	return true;
+}
+
+STATIC xfs_failaddr_t
+xfs_dquot_buf_verify(
+	struct xfs_mount	*mp,
+	struct xfs_buf		*bp,
+	bool			readahead)
+{
+	struct xfs_dqblk	*dqb = bp->b_addr;
+	xfs_failaddr_t		fa;
+	xfs_dqid_t		id = 0;
+	int			ndquots;
+	int			i;
+
+	/*
+	 * if we are in log recovery, the quota subsystem has not been
+	 * initialised so we have no quotainfo structure. In that case, we need
+	 * to manually calculate the number of dquots in the buffer.
+	 */
+	if (mp->m_quotainfo)
+		ndquots = mp->m_quotainfo->qi_dqperchunk;
+	else
+		ndquots = xfs_calc_dquots_per_chunk(bp->b_length);
+
+	/*
+	 * On the first read of the buffer, verify that each dquot is valid.
+	 * We don't know what the id of the dquot is supposed to be, just that
+	 * they should be increasing monotonically within the buffer. If the
+	 * first id is corrupt, then it will fail on the second dquot in the
+	 * buffer so corruptions could point to the wrong dquot in this case.
+	 */
+	for (i = 0; i < ndquots; i++) {
+		struct xfs_disk_dquot	*ddq;
+
+		ddq = &dqb[i].dd_diskdq;
+
+		if (i == 0)
+			id = be32_to_cpu(ddq->d_id);
+
+		fa = xfs_dqblk_verify(mp, &dqb[i], id + i, 0);
+		if (fa) {
+			if (!readahead)
+				xfs_buf_verifier_error(bp, -EFSCORRUPTED,
+					__func__, &dqb[i],
+					sizeof(struct xfs_dqblk), fa);
+			return fa;
+		}
+	}
+
+	return NULL;
+}
+
+static xfs_failaddr_t
+xfs_dquot_buf_verify_struct(
+	struct xfs_buf		*bp)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+
+	return xfs_dquot_buf_verify(mp, bp, false);
+}
+
+static void
+xfs_dquot_buf_read_verify(
+	struct xfs_buf		*bp)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+
+	if (!xfs_dquot_buf_verify_crc(mp, bp, false))
+		return;
+	xfs_dquot_buf_verify(mp, bp, false);
+}
+
+/*
+ * readahead errors are silent and simply leave the buffer as !done so a real
+ * read will then be run with the xfs_dquot_buf_ops verifier. See
+ * xfs_inode_buf_verify() for why we use EIO and ~XBF_DONE here rather than
+ * reporting the failure.
+ */
+static void
+xfs_dquot_buf_readahead_verify(
+	struct xfs_buf	*bp)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+
+	if (!xfs_dquot_buf_verify_crc(mp, bp, true) ||
+	    xfs_dquot_buf_verify(mp, bp, true) != NULL) {
+		xfs_buf_ioerror(bp, -EIO);
+		bp->b_flags &= ~XBF_DONE;
+	}
+}
+
+/*
+ * we don't calculate the CRC here as that is done when the dquot is flushed to
+ * the buffer after the update is done. This ensures that the dquot in the
+ * buffer always has an up-to-date CRC value.
+ */
+static void
+xfs_dquot_buf_write_verify(
+	struct xfs_buf		*bp)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+
+	xfs_dquot_buf_verify(mp, bp, false);
+}
+
+const struct xfs_buf_ops xfs_dquot_buf_ops = {
+	.name = "xfs_dquot",
+	.verify_read = xfs_dquot_buf_read_verify,
+	.verify_write = xfs_dquot_buf_write_verify,
+	.verify_struct = xfs_dquot_buf_verify_struct,
+};
+
+const struct xfs_buf_ops xfs_dquot_buf_ra_ops = {
+	.name = "xfs_dquot_ra",
+	.verify_read = xfs_dquot_buf_readahead_verify,
+	.verify_write = xfs_dquot_buf_write_verify,
+};