[PATCH 0/5] xfs: reverse mapping fixes

[PATCH 0/5] xfs: reverse mapping fixes

[Darrick J. Wong]

Hi all,

This is a roll-up of a few fixes[1] for reverse-mapping in 4.8.

The patches have been xfstested with the 'auto' group on x64
and (afaict) don't cause any regressions.

This is an extraordinary way to eat your data.  Enjoy! 
Comments and questions are, as always, welcome.

--D

[1] https://github.com/djwong/linux/tree/for-dave-for-4.8-6

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

[PATCH 1/5] xfs: don't log the entire end of the AGF

[Darrick J. Wong]

When we're logging the last non-spare field in the AGF, we don't
need to log the spare fields, so plumb in a new AGF logging flag
to help us avoid that.

(This patch is already in xfsprogs.)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/libxfs/xfs_alloc.c  |    2 ++
 fs/xfs/libxfs/xfs_format.h |    6 ++++--
 2 files changed, 6 insertions(+), 2 deletions(-)


diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 3dd8f1d..05b5243 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -2278,6 +2278,8 @@ xfs_alloc_log_agf(
 		offsetof(xfs_agf_t, agf_btreeblks),
 		offsetof(xfs_agf_t, agf_uuid),
 		offsetof(xfs_agf_t, agf_rmap_blocks),
+		/* needed so that we don't log the whole rest of the structure: */
+		offsetof(xfs_agf_t, agf_spare64),
 		sizeof(xfs_agf_t)
 	};
 
diff --git a/fs/xfs/libxfs/xfs_format.h b/fs/xfs/libxfs/xfs_format.h
index e6a8bea..270fb5c 100644
--- a/fs/xfs/libxfs/xfs_format.h
+++ b/fs/xfs/libxfs/xfs_format.h
@@ -674,7 +674,8 @@ typedef struct xfs_agf {
 #define	XFS_AGF_BTREEBLKS	0x00000800
 #define	XFS_AGF_UUID		0x00001000
 #define	XFS_AGF_RMAP_BLOCKS	0x00002000
-#define	XFS_AGF_NUM_BITS	14
+#define	XFS_AGF_SPARE64		0x00004000
+#define	XFS_AGF_NUM_BITS	15
 #define	XFS_AGF_ALL_BITS	((1 << XFS_AGF_NUM_BITS) - 1)
 
 #define XFS_AGF_FLAGS \
@@ -691,7 +692,8 @@ typedef struct xfs_agf {
 	{ XFS_AGF_LONGEST,	"LONGEST" }, \
 	{ XFS_AGF_BTREEBLKS,	"BTREEBLKS" }, \
 	{ XFS_AGF_UUID,		"UUID" }, \
-	{ XFS_AGF_RMAP_BLOCKS,	"RMAP_BLOCKS" }
+	{ XFS_AGF_RMAP_BLOCKS,	"RMAP_BLOCKS" }, \
+	{ XFS_AGF_SPARE64,	"SPARE64" }
 
 /* disk block (xfs_daddr_t) in the AG */
 #define XFS_AGF_DADDR(mp)	((xfs_daddr_t)(1 << (mp)->m_sectbb_log))

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

[PATCH 2/5] xfs: don't perform lookups on zero-height btrees

[Darrick J. Wong]

If the caller passes in a cursor to a zero-height btree (which is
impossible), we never set block to anything but NULL, which causes the
later dereference of it to crash.  Instead, just return -EFSCORRUPTED.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/libxfs/xfs_btree.c |    4 ++++
 1 file changed, 4 insertions(+)


diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index b5c213a..33f1406 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -1814,6 +1814,10 @@ xfs_btree_lookup(
 
 	XFS_BTREE_STATS_INC(cur, lookup);
 
+	/* No such thing as a zero-level tree. */
+	if (cur->bc_nlevels == 0)
+		return -EFSCORRUPTED;
+
 	block = NULL;
 	keyno = 0;
 

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

[PATCH 3/5] xfs: fix some key handling problems in _btree_simple_query_range

[Darrick J. Wong]

We only need the record's high key for the first record that we look
at; for all records, we /definitely/ need the regular record key.
Therefore, fix how the simple range query function gets its keys.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/libxfs/xfs_btree.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)


diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 33f1406..b70d9f9 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -4563,10 +4563,10 @@ xfs_btree_simple_query_range(
 		error = xfs_btree_get_rec(cur, &recp, &stat);
 		if (error || !stat)
 			break;
-		cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
 
 		/* Skip if high_key(rec) < low_key. */
 		if (firstrec) {
+			cur->bc_ops->init_high_key_from_rec(&rec_key, recp);
 			firstrec = false;
 			diff = cur->bc_ops->diff_two_keys(cur, low_key,
 					&rec_key);
@@ -4575,6 +4575,7 @@ xfs_btree_simple_query_range(
 		}
 
 		/* Stop if high_key < low_key(rec). */
+		cur->bc_ops->init_key_from_rec(&rec_key, recp);
 		diff = cur->bc_ops->diff_two_keys(cur, &rec_key, high_key);
 		if (diff > 0)
 			break;

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

[PATCH 4/5] xfs: simple btree query range should look right if LE lookup fails

[Darrick J. Wong]

If the initial LOOKUP_LE in the simple query range fails to find
anything, we should attempt to increment the btree cursor to see
if there actually /are/ records for what we're trying to find.
Without this patch, a bnobt range query of (0, $agsize) returns
no results because the leftmost record never has a startblock
of zero.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/libxfs/xfs_btree.c |    7 +++++++
 1 file changed, 7 insertions(+)


diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index b70d9f9..0856979 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -4558,6 +4558,13 @@ xfs_btree_simple_query_range(
 	if (error)
 		goto out;
 
+	/* Nothing?  See if there's anything to the right. */
+	if (!stat) {
+		error = xfs_btree_increment(cur, 0, &stat);
+		if (error)
+			goto out;
+	}
+
 	while (stat) {
 		/* Find the record. */
 		error = xfs_btree_get_rec(cur, &recp, &stat);

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

[PATCH 5/5] xfs: disallow mounting of realtime + rmap filesystems

[Darrick J. Wong]

Since the kernel doesn't currently support the realtime rmapbt,
don't allow such filesystems to be mounted.  Support will appear
in a future release.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/xfs/xfs_super.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)


diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 24ef83e..fd6be45 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1574,9 +1574,16 @@ xfs_fs_fill_super(
 		}
 	}
 
-	if (xfs_sb_version_hasrmapbt(&mp->m_sb))
+	if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
+		if (mp->m_sb.sb_rblocks) {
+			xfs_alert(mp,
+	"EXPERIMENTAL reverse mapping btree not compatible with realtime device!");
+			error = -EINVAL;
+			goto out_filestream_unmount;
+		}
 		xfs_alert(mp,
 	"EXPERIMENTAL reverse mapping btree feature enabled. Use at your own risk!");
+	}
 
 	error = xfs_mountfs(mp);
 	if (error)

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH 1/5] xfs: don't log the entire end of the AGF

[Christoph Hellwig]

On Tue, Aug 23, 2016 at 07:20:35PM -0700, Darrick J. Wong wrote:
> When we're logging the last non-spare field in the AGF, we don't
> need to log the spare fields, so plumb in a new AGF logging flag
> to help us avoid that.
> 
> (This patch is already in xfsprogs.)

Looks fine, and reminds me that I need to send out my patches that
fix the SGF/AGI logging API..

Reviewed-by: Christoph Hellwig <hch@lst.de>

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH 2/5] xfs: don't perform lookups on zero-height btrees

[Christoph Hellwig]

Looks fine, but could probably use an unlikely():

Reviewed-by: Christoph Hellwig <hch@lst.de>

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH 3/5] xfs: fix some key handling problems in _btree_simple_query_range

[Christoph Hellwig]

Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH 4/5] xfs: simple btree query range should look right if LE lookup fails

[Christoph Hellwig]

Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs

Re: [PATCH 5/5] xfs: disallow mounting of realtime + rmap filesystems

[Christoph Hellwig]

Looks fine,

Reviewed-by: Christoph Hellwig <hch@lst.de>

_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs