[PATCH 0/9] xfs: stable fixes for v4.19.y - circa ~ v4.19.58

[PATCH 0/9] xfs: stable fixes for v4.19.y - circa ~ v4.19.58

[Luis Chamberlain]

"Oyez Oyez..." its time for a stable update of fixes for XFS. 4 out of the
9 fixes here were recommended by Amir, and tested by both Amir and Sasha.
I've found a few other fixes, and have tested all these changes with
fstests against the following configurations in fstests sections as per
oscheck [0] and found no regressions in comparsin to v4.19.58 and by
running the full set of tests 3 times completely:

  * xfs
  * xfs_nocrc
  * xfs_nocrc_512
  * xfs_reflink
  * xfs_reflink_1024
  * xfs_logdev
  * xfs_realtimedev

Known issues are listed on the expunges files, but its no different than
the current baseline.

Worth noting is a now known generic/388 crash on xfs_nocrc, xfs_reflink,
and what may be a new section we should consider to track:
"xfs_reflink_normapbt" with the following resulting filesystem:

# xfs_info /dev/loop5
meta-data=/dev/loop5             isize=512    agcount=4, agsize=1310720 blks
         =                       sectsz=512   attr=2, projid32bit=1
         =                       crc=1        finobt=1, sparse=1, rmapbt=0
         =                       reflink=1
data     =                       bsize=4096   blocks=5242880, imaxpct=25
         =                       sunit=0      swidth=0 blks
naming   =version 2              bsize=4096   ascii-ci=0, ftype=1
log      =internal log           bsize=4096   blocks=2560, version=2
         =                       sectsz=512   sunit=0 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Do we want to create a baseline and track this configuration for stable
as well?

There is a stable bug tracking this, kz#204223 [1], and a respective bug
also present on upstream via kz#204049 [2] which Zorro reported. But,
again, nothing changes from the baseline.

I'd appreciate further reviews from the patches.

I have some other fixes in mind as well, but I'd rather not delay this
set and think this is a first good batch.

This also goes out as the first set of stable fixes using oscheck's
new devops infrastructure built on ansible / vagrant / terraform [3].
For this release I've used vagrant with KVM, perhaps the next one
I'll try terraform on whatever cloud solution someone is willing
to let me use.

You can also find these changes on my 20190718-linux-xfs-4.19.y-v1
branch on kernel.org [4].

Lemme know if you see any issues or have any questions.

[0] https://gitlab.com/mcgrof/oscheck/blob/master/fstests-configs/xfs.config
[1] https://bugzilla.kernel.org/show_bug.cgi?id=204223
[2] https://bugzilla.kernel.org/show_bug.cgi?id=204049
[3] https://gitlab.com/mcgrof/kdevops
[4] https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux-stable.git/log/?h=20190718-linux-xfs-4.19.y-v1

Brian Foster (1):
  xfs: serialize unaligned dio writes against all other dio writes

Darrick J. Wong (6):
  xfs: fix pagecache truncation prior to reflink
  xfs: don't overflow xattr listent buffer
  xfs: rename m_inotbt_nores to m_finobt_nores
  xfs: don't ever put nlink > 0 inodes on the unlinked list
  xfs: reserve blocks for ifree transaction during log recovery
  xfs: abort unaligned nowait directio early

Dave Chinner (1):
  xfs: flush removing page cache in xfs_reflink_remap_prep

Luis R. Rodriguez (1):
  xfs: fix reporting supported extra file attributes for statx()

 fs/xfs/libxfs/xfs_ag_resv.c      |  2 +-
 fs/xfs/libxfs/xfs_ialloc_btree.c |  4 ++--
 fs/xfs/xfs_attr_list.c           |  1 +
 fs/xfs/xfs_bmap_util.c           |  2 +-
 fs/xfs/xfs_bmap_util.h           |  2 ++
 fs/xfs/xfs_file.c                | 27 +++++++++++++++++----------
 fs/xfs/xfs_fsops.c               |  1 +
 fs/xfs/xfs_inode.c               | 18 +++++++-----------
 fs/xfs/xfs_iops.c                | 21 +++++++++++++++++++--
 fs/xfs/xfs_mount.h               |  2 +-
 fs/xfs/xfs_reflink.c             | 16 +++++++++++++---
 fs/xfs/xfs_super.c               |  7 +++++++
 fs/xfs/xfs_xattr.c               |  3 +++
 13 files changed, 75 insertions(+), 31 deletions(-)

-- 
2.20.1

[PATCH 1/9] xfs: fix pagecache truncation prior to reflink

[Luis Chamberlain]

From: "Darrick J. Wong" <darrick.wong@oracle.com>

commit 4918ef4ea008cd2ff47eb852894e3f9b9047f4f3 upstream.

Prior to remapping blocks, it is necessary to remove pages from the
destination file's page cache.  Unfortunately, the truncation is not
aggressive enough -- if page size > block size, we'll end up zeroing
subpage blocks instead of removing them.  So, round the start offset
down and the end offset up to page boundaries.  We already wrote all
the dirty data so the larger range shouldn't be a problem.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 fs/xfs/xfs_reflink.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 7088f44c0c59..38ea08a3dd1d 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1369,8 +1369,9 @@ xfs_reflink_remap_prep(
 		goto out_unlock;
 
 	/* Zap any page cache for the destination file's range. */
-	truncate_inode_pages_range(&inode_out->i_data, pos_out,
-				   PAGE_ALIGN(pos_out + *len) - 1);
+	truncate_inode_pages_range(&inode_out->i_data,
+			round_down(pos_out, PAGE_SIZE),
+			round_up(pos_out + *len, PAGE_SIZE) - 1);
 
 	/* If we're altering the file contents... */
 	if (!is_dedupe) {
-- 
2.20.1

[PATCH 2/9] xfs: flush removing page cache in xfs_reflink_remap_prep

[Luis Chamberlain]

From: Dave Chinner <dchinner@redhat.com>

commit 2c307174ab77e34645e75e12827646e044d273c3 upstream.

On a sub-page block size filesystem, fsx is failing with a data
corruption after a series of operations involving copying a file
with the destination offset beyond EOF of the destination of the file:

8093(157 mod 256): TRUNCATE DOWN        from 0x7a120 to 0x50000 ******WWWW
8094(158 mod 256): INSERT 0x25000 thru 0x25fff  (0x1000 bytes)
8095(159 mod 256): COPY 0x18000 thru 0x1afff    (0x3000 bytes) to 0x2f400
8096(160 mod 256): WRITE    0x5da00 thru 0x651ff        (0x7800 bytes) HOLE
8097(161 mod 256): COPY 0x2000 thru 0x5fff      (0x4000 bytes) to 0x6fc00

The second copy here is beyond EOF, and it is to sub-page (4k) but
block aligned (1k) offset. The clone runs the EOF zeroing, landing
in a pre-existing post-eof delalloc extent. This zeroes the post-eof
extents in the page cache just fine, dirtying the pages correctly.

The problem is that xfs_reflink_remap_prep() now truncates the page
cache over the range that it is copying it to, and rounds that down
to cover the entire start page. This removes the dirty page over the
delalloc extent from the page cache without having written it back.
Hence later, when the page cache is flushed, the page at offset
0x6f000 has not been written back and hence exposes stale data,
which fsx trips over less than 10 operations later.

Fix this by changing xfs_reflink_remap_prep() to use
xfs_flush_unmap_range().

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 fs/xfs/xfs_bmap_util.c |  2 +-
 fs/xfs/xfs_bmap_util.h |  2 ++
 fs/xfs/xfs_reflink.c   | 17 +++++++++++++----
 3 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 211b06e4702e..41ad9eaab6ce 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1080,7 +1080,7 @@ xfs_adjust_extent_unmap_boundaries(
 	return 0;
 }
 
-static int
+int
 xfs_flush_unmap_range(
 	struct xfs_inode	*ip,
 	xfs_off_t		offset,
diff --git a/fs/xfs/xfs_bmap_util.h b/fs/xfs/xfs_bmap_util.h
index 87363d136bb6..9c73d012f56a 100644
--- a/fs/xfs/xfs_bmap_util.h
+++ b/fs/xfs/xfs_bmap_util.h
@@ -76,6 +76,8 @@ int	xfs_swap_extents(struct xfs_inode *ip, struct xfs_inode *tip,
 xfs_daddr_t xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb);
 
 xfs_extnum_t xfs_bmap_count_leaves(struct xfs_ifork *ifp, xfs_filblks_t *count);
+int   xfs_flush_unmap_range(struct xfs_inode *ip, xfs_off_t offset,
+			    xfs_off_t len);
 int xfs_bmap_count_blocks(struct xfs_trans *tp, struct xfs_inode *ip,
 			  int whichfork, xfs_extnum_t *nextents,
 			  xfs_filblks_t *count);
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c
index 38ea08a3dd1d..f3c393f309e1 100644
--- a/fs/xfs/xfs_reflink.c
+++ b/fs/xfs/xfs_reflink.c
@@ -1368,10 +1368,19 @@ xfs_reflink_remap_prep(
 	if (ret)
 		goto out_unlock;
 
-	/* Zap any page cache for the destination file's range. */
-	truncate_inode_pages_range(&inode_out->i_data,
-			round_down(pos_out, PAGE_SIZE),
-			round_up(pos_out + *len, PAGE_SIZE) - 1);
+	/*
+	 * If pos_out > EOF, we may have dirtied blocks between EOF and
+	 * pos_out. In that case, we need to extend the flush and unmap to cover
+	 * from EOF to the end of the copy length.
+	 */
+	if (pos_out > XFS_ISIZE(dest)) {
+		loff_t	flen = *len + (pos_out - XFS_ISIZE(dest));
+		ret = xfs_flush_unmap_range(dest, XFS_ISIZE(dest), flen);
+	} else {
+		ret = xfs_flush_unmap_range(dest, pos_out, *len);
+	}
+	if (ret)
+		goto out_unlock;
 
 	/* If we're altering the file contents... */
 	if (!is_dedupe) {
-- 
2.20.1

[PATCH 3/9] xfs: don't overflow xattr listent buffer

[Luis Chamberlain]

From: "Darrick J. Wong" <darrick.wong@oracle.com>

commit 3b50086f0c0d78c144d9483fa292c1509c931b70 upstream.

For VFS listxattr calls, xfs_xattr_put_listent calls
__xfs_xattr_put_listent twice if it sees an attribute
"trusted.SGI_ACL_FILE": once for that name, and again for
"system.posix_acl_access".  Unfortunately, if we happen to run out of
buffer space while emitting the first name, we set count to -1 (so that
we can feed ERANGE to the caller).  The second invocation doesn't check that
the context parameters make sense and overwrites the byte before the
buffer, triggering a KASAN report:

==================================================================
BUG: KASAN: slab-out-of-bounds in strncpy+0xb3/0xd0
Write of size 1 at addr ffff88807fbd317f by task syz/1113

CPU: 3 PID: 1113 Comm: syz Not tainted 5.0.0-rc6-xfsx #rc6
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 dump_stack+0xcc/0x180
 print_address_description+0x6c/0x23c
 kasan_report.cold.3+0x1c/0x35
 strncpy+0xb3/0xd0
 __xfs_xattr_put_listent+0x1a9/0x2c0 [xfs]
 xfs_attr_list_int_ilocked+0x11af/0x1800 [xfs]
 xfs_attr_list_int+0x20c/0x2e0 [xfs]
 xfs_vn_listxattr+0x225/0x320 [xfs]
 listxattr+0x11f/0x1b0
 path_listxattr+0xbd/0x130
 do_syscall_64+0x139/0x560

While we're at it we add an assert to the other put_listent to avoid
this sort of thing ever happening to the attrlist_by_handle code.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 fs/xfs/xfs_attr_list.c | 1 +
 fs/xfs/xfs_xattr.c     | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/fs/xfs/xfs_attr_list.c b/fs/xfs/xfs_attr_list.c
index a58034049995..3d213a7394c5 100644
--- a/fs/xfs/xfs_attr_list.c
+++ b/fs/xfs/xfs_attr_list.c
@@ -555,6 +555,7 @@ xfs_attr_put_listent(
 	attrlist_ent_t *aep;
 	int arraytop;
 
+	ASSERT(!context->seen_enough);
 	ASSERT(!(context->flags & ATTR_KERNOVAL));
 	ASSERT(context->count >= 0);
 	ASSERT(context->count < (ATTR_MAX_VALUELEN/8));
diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
index 63ee1d5bf1d7..9a63016009a1 100644
--- a/fs/xfs/xfs_xattr.c
+++ b/fs/xfs/xfs_xattr.c
@@ -129,6 +129,9 @@ __xfs_xattr_put_listent(
 	char *offset;
 	int arraytop;
 
+	if (context->count < 0 || context->seen_enough)
+		return;
+
 	if (!context->alist)
 		goto compute_size;
 
-- 
2.20.1

[PATCH 4/9] xfs: rename m_inotbt_nores to m_finobt_nores

[Luis Chamberlain]

From: "Darrick J. Wong" <darrick.wong@oracle.com>

commit e1f6ca11381588e3ef138c10de60eeb34cb8466a upstream.

Rename this flag variable to imply more strongly that it's related to
the free inode btree (finobt) operation.  No functional changes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 fs/xfs/libxfs/xfs_ag_resv.c      | 2 +-
 fs/xfs/libxfs/xfs_ialloc_btree.c | 4 ++--
 fs/xfs/xfs_inode.c               | 2 +-
 fs/xfs/xfs_mount.h               | 2 +-
 4 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/fs/xfs/libxfs/xfs_ag_resv.c b/fs/xfs/libxfs/xfs_ag_resv.c
index e701ebc36c06..e2ba2a3b63b2 100644
--- a/fs/xfs/libxfs/xfs_ag_resv.c
+++ b/fs/xfs/libxfs/xfs_ag_resv.c
@@ -281,7 +281,7 @@ xfs_ag_resv_init(
 			 */
 			ask = used = 0;
 
-			mp->m_inotbt_nores = true;
+			mp->m_finobt_nores = true;
 
 			error = xfs_refcountbt_calc_reserves(mp, tp, agno, &ask,
 					&used);
diff --git a/fs/xfs/libxfs/xfs_ialloc_btree.c b/fs/xfs/libxfs/xfs_ialloc_btree.c
index 86c50208a143..adb2f6df5a11 100644
--- a/fs/xfs/libxfs/xfs_ialloc_btree.c
+++ b/fs/xfs/libxfs/xfs_ialloc_btree.c
@@ -124,7 +124,7 @@ xfs_finobt_alloc_block(
 	union xfs_btree_ptr	*new,
 	int			*stat)
 {
-	if (cur->bc_mp->m_inotbt_nores)
+	if (cur->bc_mp->m_finobt_nores)
 		return xfs_inobt_alloc_block(cur, start, new, stat);
 	return __xfs_inobt_alloc_block(cur, start, new, stat,
 			XFS_AG_RESV_METADATA);
@@ -157,7 +157,7 @@ xfs_finobt_free_block(
 	struct xfs_btree_cur	*cur,
 	struct xfs_buf		*bp)
 {
-	if (cur->bc_mp->m_inotbt_nores)
+	if (cur->bc_mp->m_finobt_nores)
 		return xfs_inobt_free_block(cur, bp);
 	return __xfs_inobt_free_block(cur, bp, XFS_AG_RESV_METADATA);
 }
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 05db9540e459..ae07baa7bdbf 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1754,7 +1754,7 @@ xfs_inactive_ifree(
 	 * now remains allocated and sits on the unlinked list until the fs is
 	 * repaired.
 	 */
-	if (unlikely(mp->m_inotbt_nores)) {
+	if (unlikely(mp->m_finobt_nores)) {
 		error = xfs_trans_alloc(mp, &M_RES(mp)->tr_ifree,
 				XFS_IFREE_SPACE_RES(mp), 0, XFS_TRANS_RESERVE,
 				&tp);
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index 7964513c3128..7e0bf952e087 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -127,7 +127,7 @@ typedef struct xfs_mount {
 	struct mutex		m_growlock;	/* growfs mutex */
 	int			m_fixedfsid[2];	/* unchanged for life of FS */
 	uint64_t		m_flags;	/* global mount flags */
-	bool			m_inotbt_nores; /* no per-AG finobt resv. */
+	bool			m_finobt_nores; /* no per-AG finobt resv. */
 	int			m_ialloc_inos;	/* inodes in inode allocation */
 	int			m_ialloc_blks;	/* blocks in inode allocation */
 	int			m_ialloc_min_blks;/* min blocks in sparse inode
-- 
2.20.1

[PATCH 5/9] xfs: don't ever put nlink > 0 inodes on the unlinked list

[Luis Chamberlain]

From: "Darrick J. Wong" <darrick.wong@oracle.com>

commit c4a6bf7f6cc7eb4cce120fb7eb1e1fb8b2d65e09 upstream.

When XFS creates an O_TMPFILE file, the inode is created with nlink = 1,
put on the unlinked list, and then the VFS sets nlink = 0 in d_tmpfile.
If we crash before anything logs the inode (it's dirty incore but the
vfs doesn't tell us it's dirty so we never log that change), the iunlink
processing part of recovery will then explode with a pile of:

XFS: Assertion failed: VFS_I(ip)->i_nlink == 0, file:
fs/xfs/xfs_log_recover.c, line: 5072

Worse yet, since nlink is nonzero, the inodes also don't get cleaned up
and they just leak until the next xfs_repair run.

Therefore, change xfs_iunlink to require that inodes being put on the
unlinked list have nlink == 0, change the tmpfile callers to instantiate
nodes that way, and set the nlink to 1 just prior to calling d_tmpfile.
Fix the comment for xfs_iunlink while we're at it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 fs/xfs/xfs_inode.c | 16 ++++++----------
 fs/xfs/xfs_iops.c  | 13 +++++++++++--
 2 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index ae07baa7bdbf..5ed84d6c7059 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1332,7 +1332,7 @@ xfs_create_tmpfile(
 	if (error)
 		goto out_trans_cancel;
 
-	error = xfs_dir_ialloc(&tp, dp, mode, 1, 0, prid, &ip);
+	error = xfs_dir_ialloc(&tp, dp, mode, 0, 0, prid, &ip);
 	if (error)
 		goto out_trans_cancel;
 
@@ -1907,11 +1907,8 @@ xfs_inactive(
 }
 
 /*
- * This is called when the inode's link count goes to 0 or we are creating a
- * tmpfile via O_TMPFILE. In the case of a tmpfile, @ignore_linkcount will be
- * set to true as the link count is dropped to zero by the VFS after we've
- * created the file successfully, so we have to add it to the unlinked list
- * while the link count is non-zero.
+ * This is called when the inode's link count has gone to 0 or we are creating
+ * a tmpfile via O_TMPFILE.  The inode @ip must have nlink == 0.
  *
  * We place the on-disk inode on a list in the AGI.  It will be pulled from this
  * list when the inode is freed.
@@ -1931,6 +1928,7 @@ xfs_iunlink(
 	int		offset;
 	int		error;
 
+	ASSERT(VFS_I(ip)->i_nlink == 0);
 	ASSERT(VFS_I(ip)->i_mode != 0);
 
 	/*
@@ -2837,11 +2835,9 @@ xfs_rename_alloc_whiteout(
 
 	/*
 	 * Prepare the tmpfile inode as if it were created through the VFS.
-	 * Otherwise, the link increment paths will complain about nlink 0->1.
-	 * Drop the link count as done by d_tmpfile(), complete the inode setup
-	 * and flag it as linkable.
+	 * Complete the inode setup and flag it as linkable.  nlink is already
+	 * zero, so we can skip the drop_nlink.
 	 */
-	drop_nlink(VFS_I(tmpfile));
 	xfs_setup_iops(tmpfile);
 	xfs_finish_inode_setup(tmpfile);
 	VFS_I(tmpfile)->i_state |= I_LINKABLE;
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index f48ffd7a8d3e..1efef69a7f1c 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -191,9 +191,18 @@ xfs_generic_create(
 
 	xfs_setup_iops(ip);
 
-	if (tmpfile)
+	if (tmpfile) {
+		/*
+		 * The VFS requires that any inode fed to d_tmpfile must have
+		 * nlink == 1 so that it can decrement the nlink in d_tmpfile.
+		 * However, we created the temp file with nlink == 0 because
+		 * we're not allowed to put an inode with nlink > 0 on the
+		 * unlinked list.  Therefore we have to set nlink to 1 so that
+		 * d_tmpfile can immediately set it back to zero.
+		 */
+		set_nlink(inode, 1);
 		d_tmpfile(dentry, inode);
-	else
+	} else
 		d_instantiate(dentry, inode);
 
 	xfs_finish_inode_setup(ip);
-- 
2.20.1

[PATCH 6/9] xfs: reserve blocks for ifree transaction during log recovery

[Luis Chamberlain]

From: "Darrick J. Wong" <darrick.wong@oracle.com>

commit 15a268d9f263ed3a0601a1296568241a5a3da7aa upstream.

Log recovery frees all the inodes stored in the unlinked list, which can
cause expansion of the free inode btree.  The ifree code skips block
reservations if it thinks there's a per-AG space reservation, but we
don't set up the reservation until after log recovery, which means that
a finobt expansion blows up in xfs_trans_mod_sb when we exceed the
transaction's block reservation.

To fix this, we set the "no finobt reservation" flag to true when we
create the xfs_mount and only set it to false if we confirm that every
AG had enough free space to put aside for the finobt.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 fs/xfs/xfs_fsops.c | 1 +
 fs/xfs/xfs_super.c | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 7c00b8bedfe3..09fd602507ef 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -534,6 +534,7 @@ xfs_fs_reserve_ag_blocks(
 	int			error = 0;
 	int			err2;
 
+	mp->m_finobt_nores = false;
 	for (agno = 0; agno < mp->m_sb.sb_agcount; agno++) {
 		pag = xfs_perag_get(mp, agno);
 		err2 = xfs_ag_resv_init(pag, NULL);
diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 207ee302b1bb..dce8114e3198 100644
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -1561,6 +1561,13 @@ xfs_mount_alloc(
 	INIT_DELAYED_WORK(&mp->m_eofblocks_work, xfs_eofblocks_worker);
 	INIT_DELAYED_WORK(&mp->m_cowblocks_work, xfs_cowblocks_worker);
 	mp->m_kobj.kobject.kset = xfs_kset;
+	/*
+	 * We don't create the finobt per-ag space reservation until after log
+	 * recovery, so we must set this to true so that an ifree transaction
+	 * started during log recovery will not depend on space reservations
+	 * for finobt expansion.
+	 */
+	mp->m_finobt_nores = true;
 	return mp;
 }
 
-- 
2.20.1

[PATCH 7/9] xfs: fix reporting supported extra file attributes for statx()

[Luis Chamberlain]

From: "Luis R. Rodriguez" <mcgrof@kernel.org>

commit 1b9598c8fb9965fff901c4caa21fed9644c34df3 upstream.

statx(2) notes that any attribute that is not indicated as supported by
stx_attributes_mask has no usable value. Commit 5f955f26f3d42d ("xfs: report
crtime and attribute flags to statx") added support for informing userspace
of extra file attributes but forgot to list these flags as supported
making reporting them rather useless for the pedantic userspace author.

$ git describe --contains 5f955f26f3d42d04aba65590a32eb70eedb7f37d
v4.11-rc6~5^2^2~2

Fixes: 5f955f26f3d42d ("xfs: report crtime and attribute flags to statx")
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
[darrick: add a comment reminding people to keep attributes_mask up to date]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 fs/xfs/xfs_iops.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 1efef69a7f1c..74047bd0c1ae 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -531,6 +531,10 @@ xfs_vn_getattr(
 		}
 	}
 
+	/*
+	 * Note: If you add another clause to set an attribute flag, please
+	 * update attributes_mask below.
+	 */
 	if (ip->i_d.di_flags & XFS_DIFLAG_IMMUTABLE)
 		stat->attributes |= STATX_ATTR_IMMUTABLE;
 	if (ip->i_d.di_flags & XFS_DIFLAG_APPEND)
@@ -538,6 +542,10 @@ xfs_vn_getattr(
 	if (ip->i_d.di_flags & XFS_DIFLAG_NODUMP)
 		stat->attributes |= STATX_ATTR_NODUMP;
 
+	stat->attributes_mask |= (STATX_ATTR_IMMUTABLE |
+				  STATX_ATTR_APPEND |
+				  STATX_ATTR_NODUMP);
+
 	switch (inode->i_mode & S_IFMT) {
 	case S_IFBLK:
 	case S_IFCHR:
-- 
2.20.1

[PATCH 8/9] xfs: serialize unaligned dio writes against all other dio writes

[Luis Chamberlain]

From: Brian Foster <bfoster@redhat.com>

commit 2032a8a27b5cc0f578d37fa16fa2494b80a0d00a upstream.

XFS applies more strict serialization constraints to unaligned
direct writes to accommodate things like direct I/O layer zeroing,
unwritten extent conversion, etc. Unaligned submissions acquire the
exclusive iolock and wait for in-flight dio to complete to ensure
multiple submissions do not race on the same block and cause data
corruption.

This generally works in the case of an aligned dio followed by an
unaligned dio, but the serialization is lost if I/Os occur in the
opposite order. If an unaligned write is submitted first and
immediately followed by an overlapping, aligned write, the latter
submits without the typical unaligned serialization barriers because
there is no indication of an unaligned dio still in-flight. This can
lead to unpredictable results.

To provide proper unaligned dio serialization, require that such
direct writes are always the only dio allowed in-flight at one time
for a particular inode. We already acquire the exclusive iolock and
drain pending dio before submitting the unaligned dio. Wait once
more after the dio submission to hold the iolock across the I/O and
prevent further submissions until the unaligned I/O completes. This
is heavy handed, but consistent with the current pre-submission
serialization for unaligned direct writes.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 fs/xfs/xfs_file.c | 27 +++++++++++++++++----------
 1 file changed, 17 insertions(+), 10 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 61a5ad2600e8..10f75965243c 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -529,18 +529,17 @@ xfs_file_dio_aio_write(
 	count = iov_iter_count(from);
 
 	/*
-	 * If we are doing unaligned IO, wait for all other IO to drain,
-	 * otherwise demote the lock if we had to take the exclusive lock
-	 * for other reasons in xfs_file_aio_write_checks.
+	 * If we are doing unaligned IO, we can't allow any other overlapping IO
+	 * in-flight at the same time or we risk data corruption. Wait for all
+	 * other IO to drain before we submit. If the IO is aligned, demote the
+	 * iolock if we had to take the exclusive lock in
+	 * xfs_file_aio_write_checks() for other reasons.
 	 */
 	if (unaligned_io) {
-		/* If we are going to wait for other DIO to finish, bail */
-		if (iocb->ki_flags & IOCB_NOWAIT) {
-			if (atomic_read(&inode->i_dio_count))
-				return -EAGAIN;
-		} else {
-			inode_dio_wait(inode);
-		}
+		/* unaligned dio always waits, bail */
+		if (iocb->ki_flags & IOCB_NOWAIT)
+			return -EAGAIN;
+		inode_dio_wait(inode);
 	} else if (iolock == XFS_IOLOCK_EXCL) {
 		xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
 		iolock = XFS_IOLOCK_SHARED;
@@ -548,6 +547,14 @@ xfs_file_dio_aio_write(
 
 	trace_xfs_file_direct_write(ip, count, iocb->ki_pos);
 	ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, xfs_dio_write_end_io);
+
+	/*
+	 * If unaligned, this is the only IO in-flight. If it has not yet
+	 * completed, wait on it before we release the iolock to prevent
+	 * subsequent overlapping IO.
+	 */
+	if (ret == -EIOCBQUEUED && unaligned_io)
+		inode_dio_wait(inode);
 out:
 	xfs_iunlock(ip, iolock);
 
-- 
2.20.1

[PATCH 9/9] xfs: abort unaligned nowait directio early

[Luis Chamberlain]

From: "Darrick J. Wong" <darrick.wong@oracle.com>

commit 1fdeaea4d92c69fb9f871a787af6ad00f32eeea7 upstream.

Dave Chinner noticed that xfs_file_dio_aio_write returns EAGAIN without
dropping the IOLOCK when its deciding not to wait, which means that we
leak the IOLOCK there.  Since we now make unaligned directio always
wait, we have the opportunity to bail out before trying to take the
lock, which should reduce the overhead of this never-gonna-work case
considerably while also solving the dropped lock problem.

Reported-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
---
 fs/xfs/xfs_file.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 10f75965243c..259549698ba7 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -517,6 +517,9 @@ xfs_file_dio_aio_write(
 	}
 
 	if (iocb->ki_flags & IOCB_NOWAIT) {
+		/* unaligned dio always waits, bail */
+		if (unaligned_io)
+			return -EAGAIN;
 		if (!xfs_ilock_nowait(ip, iolock))
 			return -EAGAIN;
 	} else {
@@ -536,9 +539,6 @@ xfs_file_dio_aio_write(
 	 * xfs_file_aio_write_checks() for other reasons.
 	 */
 	if (unaligned_io) {
-		/* unaligned dio always waits, bail */
-		if (iocb->ki_flags & IOCB_NOWAIT)
-			return -EAGAIN;
 		inode_dio_wait(inode);
 	} else if (iolock == XFS_IOLOCK_EXCL) {
 		xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
-- 
2.20.1

Re: [PATCH 0/9] xfs: stable fixes for v4.19.y - circa ~ v4.19.58

[Luis Chamberlain]

On Thu, Jul 18, 2019 at 11:06:08PM +0000, Luis Chamberlain wrote:
> There is a stable bug tracking this, kz#204223 [1], and a respective bug
> also present on upstream via kz#204049 [2] which Zorro reported. But,
> again, nothing changes from the baseline.

The crash is fixed by Brian's commit 6958d11f77d ("xfs: don't trip over
uninitialized buffer on extent read of corrupted inode") merged on v5.1.

As such I'll extend this series to include one more patch.

  Luis

Re: [PATCH 0/9] xfs: stable fixes for v4.19.y - circa ~ v4.19.58

[Sasha Levin]

On Fri, Jul 19, 2019 at 07:23:11PM +0000, Luis Chamberlain wrote:
>On Thu, Jul 18, 2019 at 11:06:08PM +0000, Luis Chamberlain wrote:
>> There is a stable bug tracking this, kz#204223 [1], and a respective bug
>> also present on upstream via kz#204049 [2] which Zorro reported. But,
>> again, nothing changes from the baseline.
>
>The crash is fixed by Brian's commit 6958d11f77d ("xfs: don't trip over
>uninitialized buffer on extent read of corrupted inode") merged on v5.1.
>
>As such I'll extend this series to include one more patch.

I've queued this series up, thanks!

--
Thanks,
Sasha