[PATCH 04/30] xfs: split dquot buffer operations out

Dave Chinner
2013-10-30T04:31:36Z

From: Dave Chinner <dchinner@redhat.com>

Parts of userspace want to be able to read and modify dquot buffers
(e.g. xfs_db) so we need to split out the reading and writing of
these buffers so it is easy to shared code with libxfs in userspace.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
---
include/libxfs.h | 9 ++
libxfs/Makefile | 1 +
libxfs/xfs_dquot_buf.c | 273 +++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 283 insertions(+)
create mode 100644 libxfs/xfs_dquot_buf.c

diff --git a/include/libxfs.h b/include/libxfs.h
index 835ba37..f10ab59 100644
--- a/include/libxfs.h
+++ b/include/libxfs.h
@@ -216,6 +216,15 @@ typedef struct xfs_mount {
xfs_dablk_t m_dirdatablk; /* blockno of dir data v2 */
xfs_dablk_t m_dirleafblk; /* blockno of dir non-data v2 */
xfs_dablk_t m_dirfreeblk; /* blockno of dirfreeindex v2 */
+
+ /*
+ * anonymous struct to allow xfs_dquot_buf.c to compile.
+ * Pointer is always null in userspace, so code does not use it at all
+ */
+ struct {
+ int qi_dqperchunk;
+ } *m_quotainfo;
+
} xfs_mount_t;

/*
diff --git a/libxfs/Makefile b/libxfs/Makefile
index f0cbae3..4522218 100644
--- a/libxfs/Makefile
+++ b/libxfs/Makefile
@@ -29,6 +29,7 @@ CFILES = cache.c \
xfs_dir2_leaf.c \
xfs_dir2_node.c \
xfs_dir2_sf.c \
+ xfs_dquot_buf.c \
xfs_ialloc.c \
xfs_inode_buf.c \
xfs_inode_fork.c \
diff --git a/libxfs/xfs_dquot_buf.c b/libxfs/xfs_dquot_buf.c
new file mode 100644
index 0000000..620d9d3
--- /dev/null
+++ b/libxfs/xfs_dquot_buf.c
@@ -0,0 +1,273 @@
+/*
+ * 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"
+
+int
+xfs_calc_dquots_per_chunk(
+ struct xfs_mount *mp,
+ 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(mp,
+ 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(mp, 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_dquot_buf_verify(mp, bp)) {
+ XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+ xfs_buf_ioerror(bp, EFSCORRUPTED);
+ }
+}
+
+/*
+ * 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.
+ */
+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_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+ xfs_buf_ioerror(bp, EFSCORRUPTED);
+ return;
+ }
+}
+
+const struct xfs_buf_ops xfs_dquot_buf_ops = {
+ .verify_read = xfs_dquot_buf_read_verify,
+ .verify_write = xfs_dquot_buf_write_verify,
+};
+
--
1.8.4.rc3