Re: [RFC PATCH v3 9/9] xfs: Implement ->corrupted_range() for XFS
From: Ruan Shiyang
Date: Thu Dec 17 2020 - 21:36:01 EST
On 2020/12/16 上午4:40, Darrick J. Wong wrote:
On Tue, Dec 15, 2020 at 08:14:14PM +0800, Shiyang Ruan wrote:
This function is used to handle errors which may cause data lost in
filesystem. Such as memory failure in fsdax mode.
In XFS, it requires "rmapbt" feature in order to query for files or
metadata which associated to the corrupted data. Then we could call fs
recover functions to try to repair the corrupted data.(did not
implemented in this patchset)
After that, the memory failure also 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@xxxxxxxxxxxxxx>
---
fs/xfs/xfs_fsops.c | 10 +++++
fs/xfs/xfs_mount.h | 2 +
fs/xfs/xfs_super.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 105 insertions(+)
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index ef1d5bb88b93..0ec1b44bfe88 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -501,6 +501,16 @@ 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 (flags & SHUTDOWN_CORRUPT_DATA) {
+ xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_CORRUPT,
+"Corruption of on-disk file data 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 dfa429b77ee2..e36c07553486 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -274,6 +274,8 @@ 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 */
+#define SHUTDOWN_CORRUPT_DATA 0x0020 /* corrupt file data on device */
This symbol isn't used anywhere. I don't know why we'd shut down the fs
for data loss, as we don't do that anywhere else in xfs.
I prepared this flag for the later use if possible. But since it seems
unnecessary, I will remove it in the next version.
/*
* Flags for xfs_mountfs
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index e3e229e52512..30202de7e89d 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -35,6 +35,11 @@
#include "xfs_refcount_item.h"
#include "xfs_bmap_item.h"
#include "xfs_reflink.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>
@@ -1103,6 +1108,93 @@ 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;
+ int rc = 0;
Note: we usually use the name "error", not "rc".
OK.
+ int *flags = data;
+
+ if (XFS_RMAP_NON_INODE_OWNER(rec->rm_owner)) {
There are a few more things to check here to detect if metadata has been
lost. The first is that any loss in the extended attribute information
is considered filesystem metadata; and the second is that loss of an
extent btree block is also metadata.
IOWs, this check should be:
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
return -EFSCORRUPTED;
}
Thanks for pointing out.
+ // TODO check and try to fix metadata
+ rc = -EFSCORRUPTED;
+ } else {
+ /*
+ * 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 || !ip)
+ return rc;
+ if (!VFS_I(ip)->i_mapping)
+ goto out;
+
+ if (IS_DAX(VFS_I(ip)))
+ rc = mf_dax_mapping_kill_procs(VFS_I(ip)->i_mapping,
+ rec->rm_offset, *flags);
If the file isn't S_DAX, should we call mapping_set_error here so
that the next fsync() will also return EIO?
Nice idea. I will try.
+
+ // TODO try to fix data
+out:
+ 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 bc = 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 rc = 0;
+
+ if (mp->m_rtdev_targp && mp->m_rtdev_targp->bt_bdev == bdev) {
+ xfs_warn(mp, "storage lost support not available for realtime device!");
+ return 0;
+ }
This ought to kill the fs when an external log device is configured:
if (mp->m_logdev_targp &&
mp->m_logdev_targp != mp->m_ddev_targp &&
mp->m_logdev_targp->bt_bdev == bdev) {
xfs_error(mp, "ondisk log corrupt, shutting down fs!");
xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_META);
return 0;
}
Then, we need to check explicitly for rmap support:
if (!xfs_sb_version_hasrmapbt(&mp->m_sb))
return 0;
so that we screen out filesystems that don't have rmap enabled.
Ah... I was too negligent to think of this. That's very thoughtful of
you. Thanks.
+ rc = xfs_trans_alloc_empty(mp, &tp);
+ if (rc)
+ return rc;
+
+ rc = xfs_alloc_read_agf(mp, tp, agno, 0, &agf_bp);
+ if (rc)
+ return rc;
+
+ 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 = bc;
+
+ rc = xfs_rmap_query_range(cur, &rmap_low, &rmap_high, xfs_corrupt_helper, data);
+ if (rc == -ECANCELED)
+ rc = 0;
I don't think anything returns ECANCELED here...
Yes. Will remove it.
--
Thanks,
Ruan Shiyang.
--D
+ if (rc == -EFSCORRUPTED)
+ xfs_force_shutdown(mp, SHUTDOWN_CORRUPT_META);
+
+ xfs_btree_del_cursor(cur, rc);
+ xfs_trans_brelse(tp, agf_bp);
+ return rc;
+}
+
static const struct super_operations xfs_super_operations = {
.alloc_inode = xfs_fs_alloc_inode,
.destroy_inode = xfs_fs_destroy_inode,
@@ -1116,6 +1208,7 @@ 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
--
2.29.2