1 files changed, 290 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 000000000000..bb969337efc8
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_dquot_buf.c
@@ -0,0 +1,290 @@
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * Copyright (c) 2013 Red Hat, Inc.
+ * All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+#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_sb.h"
+#include "xfs_ag.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 */
+{
+        unsigned int    ndquots;
+
+        ASSERT(nbblks > 0);
+        ndquots = BBTOB(nbblks);
+        do_div(ndquots, sizeof(xfs_dqblk_t));
+
+        return ndquots;
+}
+
+/*
+ * Do some primitive error checking on ondisk dquot data structures.
+ */
+int
+xfs_dqcheck(
+        struct xfs_mount *mp,
+        xfs_disk_dquot_t *ddq,
+        xfs_dqid_t       id,
+        uint             type,    /* used only when IO_dorepair is true */
+        uint             flags,
+        char             *str)
+{
+        xfs_dqblk_t      *d = (xfs_dqblk_t *)ddq;
+        int             errs = 0;
+
+        /*
+         * 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)) {
+                if (flags & XFS_QMOPT_DOWARN)
+                        xfs_alert(mp,
+                        "%s : XFS dquot ID 0x%x, magic 0x%x != 0x%x",
+                        str, id, be16_to_cpu(ddq->d_magic), XFS_DQUOT_MAGIC);
+                errs++;
+        }
+        if (ddq->d_version != XFS_DQUOT_VERSION) {
+                if (flags & XFS_QMOPT_DOWARN)
+                        xfs_alert(mp,
+                        "%s : XFS dquot ID 0x%x, version 0x%x != 0x%x",
+                        str, id, ddq->d_version, XFS_DQUOT_VERSION);
+                errs++;
+        }
+
+        if (ddq->d_flags != XFS_DQ_USER &&
+            ddq->d_flags != XFS_DQ_PROJ &&
+            ddq->d_flags != XFS_DQ_GROUP) {
+                if (flags & XFS_QMOPT_DOWARN)
+                        xfs_alert(mp,
+                        "%s : XFS dquot ID 0x%x, unknown flags 0x%x",
+                        str, id, ddq->d_flags);
+                errs++;
+        }
+
+        if (id != -1 && id != be32_to_cpu(ddq->d_id)) {
+                if (flags & XFS_QMOPT_DOWARN)
+                        xfs_alert(mp,
+                        "%s : ondisk-dquot 0x%p, ID mismatch: "
+                        "0x%x expected, found id 0x%x",
+                        str, ddq, id, be32_to_cpu(ddq->d_id));
+                errs++;
+        }
+
+        if (!errs && ddq->d_id) {
+                if (ddq->d_blk_softlimit &&
+                    be64_to_cpu(ddq->d_bcount) >
+                                be64_to_cpu(ddq->d_blk_softlimit)) {
+                        if (!ddq->d_btimer) {
+                                if (flags & XFS_QMOPT_DOWARN)
+                                        xfs_alert(mp,
+                        "%s : Dquot ID 0x%x (0x%p) BLK TIMER NOT STARTED",
+                                        str, (int)be32_to_cpu(ddq->d_id), ddq);
+                                errs++;
+                        }
+                }
+                if (ddq->d_ino_softlimit &&
+                    be64_to_cpu(ddq->d_icount) >
+                                be64_to_cpu(ddq->d_ino_softlimit)) {
+                        if (!ddq->d_itimer) {
+                                if (flags & XFS_QMOPT_DOWARN)
+                                        xfs_alert(mp,
+                        "%s : Dquot ID 0x%x (0x%p) INODE TIMER NOT STARTED",
+                                        str, (int)be32_to_cpu(ddq->d_id), ddq);
+                                errs++;
+                        }
+                }
+                if (ddq->d_rtb_softlimit &&
+                    be64_to_cpu(ddq->d_rtbcount) >
+                                be64_to_cpu(ddq->d_rtb_softlimit)) {
+                        if (!ddq->d_rtbtimer) {
+                                if (flags & XFS_QMOPT_DOWARN)
+                                        xfs_alert(mp,
+                        "%s : Dquot ID 0x%x (0x%p) RTBLK TIMER NOT STARTED",
+                                        str, (int)be32_to_cpu(ddq->d_id), ddq);
+                                errs++;
+                        }
+                }
+        }
+
+        if (!errs || !(flags & XFS_QMOPT_DQREPAIR))
+                return errs;
+
+        if (flags & XFS_QMOPT_DOWARN)
+                xfs_notice(mp, "Re-initializing dquot ID 0x%x", id);
+
+        /*
+         * Typically, a repair is only requested by quotacheck.
+         */
+        ASSERT(id != -1);
+        ASSERT(flags & XFS_QMOPT_DQREPAIR);
+        memset(d, 0, sizeof(xfs_dqblk_t));
+
+        d->dd_diskdq.d_magic = cpu_to_be16(XFS_DQUOT_MAGIC);
+        d->dd_diskdq.d_version = XFS_DQUOT_VERSION;
+        d->dd_diskdq.d_flags = type;
+        d->dd_diskdq.d_id = cpu_to_be32(id);
+
+        if (xfs_sb_version_hascrc(&mp->m_sb)) {
+                uuid_copy(&d->dd_uuid, &mp->m_sb.sb_uuid);
+                xfs_update_cksum((char *)d, sizeof(struct xfs_dqblk),
+                                 XFS_DQUOT_CRC_OFF);
+        }
+
+        return errs;
+}
+
+STATIC bool
+xfs_dquot_buf_verify_crc(
+        struct xfs_mount        *mp,
+        struct xfs_buf          *bp)
+{
+        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(
+                                        XFS_BB_TO_FSB(mp, bp->b_length));
+
+        for (i = 0; i < ndquots; i++, d++) {
+                if (!xfs_verify_cksum((char *)d, sizeof(struct xfs_dqblk),
+                                 XFS_DQUOT_CRC_OFF))
+                        return false;
+                if (!uuid_equal(&d->dd_uuid, &mp->m_sb.sb_uuid))
+                        return false;
+        }
+        return true;
+}
+
+STATIC bool
+xfs_dquot_buf_verify(
+        struct xfs_mount        *mp,
+        struct xfs_buf          *bp)
+{
+        struct xfs_dqblk        *d = (struct xfs_dqblk *)bp->b_addr;
+        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;
+                int                     error;
+
+                ddq = &d[i].dd_diskdq;
+
+                if (i == 0)
+                        id = be32_to_cpu(ddq->d_id);
+
+                error = xfs_dqcheck(mp, ddq, id + i, 0, XFS_QMOPT_DOWARN,
+                                       "xfs_dquot_buf_verify");
+                if (error)
+                        return false;
+        }
+        return true;
+}
+
+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))
+                xfs_buf_ioerror(bp, -EFSBADCRC);
+        else if (!xfs_dquot_buf_verify(mp, bp))
+                xfs_buf_ioerror(bp, -EFSCORRUPTED);
+
+        if (bp->b_error)
+                xfs_verifier_error(bp);
+}
+
+/*
+ * 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;
+
+        if (!xfs_dquot_buf_verify(mp, bp)) {
+                xfs_buf_ioerror(bp, -EFSCORRUPTED);
+                xfs_verifier_error(bp);
+                return;
+        }
+}
+
+const struct xfs_buf_ops xfs_dquot_buf_ops = {
+        .verify_read = xfs_dquot_buf_read_verify,
+        .verify_write = xfs_dquot_buf_write_verify,
+};
+