[PATCH v4 09/10] xfs: Implement ->corrupted_range() for XFS

Shiyang Ruan
2021-06-04T01:19:53Z

This function is used to handle errors which may cause data lost in
filesystem. Such as memory failure in fsdax mode.

If the rmap feature of XFS enabled, we can query it to find files and
metadata which are associated with the corrupt data. For now all we do
is kill processes with that file mapped into their address spaces, but
future patches could actually do something about corrupt metadata.

After that, the memory failure needs to notify the processes who are
using those files.

Only support data device. Realtime device is not supported for now.

Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
---
fs/xfs/xfs_fsops.c | 5 +++
fs/xfs/xfs_mount.h | 1 +
fs/xfs/xfs_super.c | 108 +++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 114 insertions(+)

diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index be9cf88d2ad7..e89ada33d8fc 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -551,6 +551,11 @@ xfs_do_force_shutdown(
"Corruption of in-memory data detected. Shutting down filesystem");
if (XFS_ERRLEVEL_HIGH <= xfs_error_level)
xfs_stack_trace();
+ } else if (flags & SHUTDOWN_CORRUPT_META) {
+ xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_CORRUPT,
+"Corruption of on-disk metadata detected. Shutting down filesystem");
+ if (XFS_ERRLEVEL_HIGH <= xfs_error_level)
+ xfs_stack_trace();
} else if (logerror) {
xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_LOGERROR,
"Log I/O Error Detected. Shutting down filesystem");
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index bb67274ee23f..c62ccf3e07d0 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -276,6 +276,7 @@ void xfs_do_force_shutdown(struct xfs_mount *mp, int flags, char *fname,
#define SHUTDOWN_LOG_IO_ERROR 0x0002 /* write attempt to the log failed */
#define SHUTDOWN_FORCE_UMOUNT 0x0004 /* shutdown from a forced unmount */
#define SHUTDOWN_CORRUPT_INCORE 0x0008 /* corrupt in-memory data structures */
+#define SHUTDOWN_CORRUPT_META 0x0010 /* corrupt metadata on device */

/*
* Flags for xfs_mountfs
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index a2dab05332ac..498edaeb8363 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -36,6 +36,11 @@
#include "xfs_bmap_item.h"
#include "xfs_reflink.h"
#include "xfs_pwork.h"
+#include "xfs_alloc.h"
+#include "xfs_rmap.h"
+#include "xfs_rmap_btree.h"
+#include "xfs_rtalloc.h"
+#include "xfs_bit.h"

#include <linux/magic.h>
#include <linux/fs_context.h>
@@ -392,6 +397,7 @@ xfs_open_devices(
struct block_device *logdev = NULL, *rtdev = NULL;
int error;

+ dax_set_holder(dax_ddev, mp->m_super, &fs_dax_holder_ops);
/*
* Open real time and log devices - order is important.
*/
@@ -400,6 +406,9 @@ xfs_open_devices(
if (error)
goto out;
dax_logdev = fs_dax_get_by_bdev(logdev);
+ if (dax_logdev != dax_ddev)
+ dax_set_holder(dax_logdev, mp->m_super,
+ &fs_dax_holder_ops);
}

if (mp->m_rtname) {
@@ -414,6 +423,7 @@ xfs_open_devices(
goto out_close_rtdev;
}
dax_rtdev = fs_dax_get_by_bdev(rtdev);
+ dax_set_holder(dax_rtdev, mp->m_super, &fs_dax_holder_ops);
}

/*
@@ -1076,6 +1086,103 @@ xfs_fs_free_cached_objects(
return xfs_reclaim_inodes_nr(XFS_M(sb), sc->nr_to_scan);
}

+static int
+xfs_corrupt_helper(
+ struct xfs_btree_cur *cur,
+ struct xfs_rmap_irec *rec,
+ void *data)
+{
+ struct xfs_inode *ip;
+ struct address_space *mapping;
+ int rc = 0;
+ int *flags = data;
+
+ if (XFS_RMAP_NON_INODE_OWNER(rec->rm_owner) ||
+ (rec->rm_flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK))) {
+ // TODO check and try to fix metadata
+ xfs_force_shutdown(cur->bc_mp, SHUTDOWN_CORRUPT_META);
+ return -EFSCORRUPTED;
+ }
+
+ /*
+ * Get files that incore, filter out others that are not in use.
+ */
+ rc = xfs_iget(cur->bc_mp, cur->bc_tp, rec->rm_owner, XFS_IGET_INCORE,
+ 0, &ip);
+ if (rc)
+ return rc;
+
+ mapping = VFS_I(ip)->i_mapping;
+ rc = mf_dax_kill_procs(mapping, rec->rm_offset, *flags);
+
+ // TODO try to fix data
+ xfs_irele(ip);
+
+ return rc;
+}
+
+static int
+xfs_fs_corrupted_range(
+ struct super_block *sb,
+ struct block_device *bdev,
+ loff_t offset,
+ size_t len,
+ void *data)
+{
+ struct xfs_mount *mp = XFS_M(sb);
+ struct xfs_trans *tp = NULL;
+ struct xfs_btree_cur *cur = NULL;
+ struct xfs_rmap_irec rmap_low, rmap_high;
+ struct xfs_buf *agf_bp = NULL;
+ xfs_fsblock_t fsbno = XFS_B_TO_FSB(mp, offset);
+ xfs_filblks_t bcnt = XFS_B_TO_FSB(mp, len);
+ xfs_agnumber_t agno = XFS_FSB_TO_AGNO(mp, fsbno);
+ xfs_agblock_t agbno = XFS_FSB_TO_AGBNO(mp, fsbno);
+ int error = 0;
+
+ if (mp->m_rtdev_targp && mp->m_rtdev_targp->bt_bdev == bdev) {
+ xfs_warn(mp, "corrupted_range support not available for realtime device!");
+ return -EOPNOTSUPP;
+ }
+ if (mp->m_logdev_targp && mp->m_logdev_targp->bt_bdev == bdev &&
+ mp->m_logdev_targp != mp->m_ddev_targp) {
+ xfs_err(mp, "ondisk log corrupt, shutting down fs!");
+ xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_META);
+ return -EFSCORRUPTED;
+ }
+
+ if (!xfs_sb_version_hasrmapbt(&mp->m_sb)) {
+ xfs_warn(mp, "corrupted_range needs rmapbt enabled!");
+ return -EOPNOTSUPP;
+ }
+
+ error = xfs_trans_alloc_empty(mp, &tp);
+ if (error)
+ return error;
+
+ error = xfs_alloc_read_agf(mp, tp, agno, 0, &agf_bp);
+ if (error)
+ goto out_cancel_tp;
+
+ cur = xfs_rmapbt_init_cursor(mp, tp, agf_bp, agno);
+
+ /* Construct a range for rmap query */
+ memset(&rmap_low, 0, sizeof(rmap_low));
+ memset(&rmap_high, 0xFF, sizeof(rmap_high));
+ rmap_low.rm_startblock = rmap_high.rm_startblock = agbno;
+ rmap_low.rm_blockcount = rmap_high.rm_blockcount = bcnt;
+
+ error = xfs_rmap_query_range(cur, &rmap_low, &rmap_high,
+ xfs_corrupt_helper, data);
+
+ xfs_btree_del_cursor(cur, error);
+ xfs_trans_brelse(tp, agf_bp);
+
+out_cancel_tp:
+ xfs_trans_cancel(tp);
+ return error;
+}
+
static const struct super_operations xfs_super_operations = {
.alloc_inode = xfs_fs_alloc_inode,
.destroy_inode = xfs_fs_destroy_inode,
@@ -1089,6 +1196,7 @@ static const struct super_operations xfs_super_operations = {
.show_options = xfs_fs_show_options,
.nr_cached_objects = xfs_fs_nr_cached_objects,
.free_cached_objects = xfs_fs_free_cached_objects,
+ .corrupted_range = xfs_fs_corrupted_range,
};

static int
--
2.31.1