[PATCH 5.4 CANDIDATE 0/3] Fixes for patches backported to 5.4.y from v5.7

[PATCH 5.4 CANDIDATE 0/3] Fixes for patches backported to 5.4.y from v5.7

[Chandan Babu R]

Hi Darrick,

Patches backported from v5.7 to 5.4.y had fixes from newer versions of
Linux kernel. I had missed including these patches in my previous
patchset posting.

This patchset has been tested by executing fstests (via kdevops) using
the following XFS configurations,

1. No CRC (with 512 and 4k block size).
2. Reflink/Rmapbt (1k and 4k block size).
3. Reflink without Rmapbt.
4. External log device.

Brian Foster (1):
  xfs: finish dfops on every insert range shift iteration

Darrick J. Wong (2):
  xfs: clear XFS_DQ_FREEING if we can't lock the dquot buffer to flush
  xfs: force the log after remapping a synchronous-writes file

 fs/xfs/xfs_bmap_util.c |  2 +-
 fs/xfs/xfs_file.c      | 17 ++++++++++++++++-
 fs/xfs/xfs_qm.c        |  1 +
 3 files changed, 18 insertions(+), 2 deletions(-)

-- 
2.35.1

[PATCH 5.4 CANDIDATE 1/3] xfs: finish dfops on every insert range shift iteration

[Chandan Babu R]

From: Brian Foster <bfoster@redhat.com>

commit 9c516e0e4554e8f26ab73d46cbc789d7d8db664d upstream.

The recent change to make insert range an atomic operation used the
incorrect transaction rolling mechanism. The explicit transaction
roll does not finish deferred operations. This means that intents
for rmapbt updates caused by extent shifts are not logged until the
final transaction commits. Thus if a crash occurs during an insert
range, log recovery might leave the rmapbt in an inconsistent state.
This was discovered by repeated runs of generic/455.

Update insert range to finish dfops on every shift iteration. This
is similar to collapse range and ensures that intents are logged
with the transactions that make associated changes.

Fixes: dd87f87d87fa ("xfs: rework insert range into an atomic operation")
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
---
 fs/xfs/xfs_bmap_util.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_bmap_util.c b/fs/xfs/xfs_bmap_util.c
index 5b211cb8b579..12c12c2ef241 100644
--- a/fs/xfs/xfs_bmap_util.c
+++ b/fs/xfs/xfs_bmap_util.c
@@ -1340,7 +1340,7 @@ xfs_insert_file_space(
 		goto out_trans_cancel;
 
 	do {
-		error = xfs_trans_roll_inode(&tp, ip);
+		error = xfs_defer_finish(&tp);
 		if (error)
 			goto out_trans_cancel;
 
-- 
2.35.1

[PATCH 5.4 CANDIDATE 2/3] xfs: clear XFS_DQ_FREEING if we can't lock the dquot buffer to flush

[Chandan Babu R]

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

commit c97738a960a86081a147e7d436138e6481757445 upstream.

In commit 8d3d7e2b35ea, we changed xfs_qm_dqpurge to bail out if we
can't lock the dquot buf to flush the dquot.  This prevents the AIL from
blocking on the dquot, but it also forgets to clear the FREEING flag on
its way out.  A subsequent purge attempt will see the FREEING flag is
set and bail out, which leads to dqpurge_all failing to purge all the
dquots.

(copy-pasting from Dave Chinner's identical patch)

This was found by inspection after having xfs/305 hang 1 in ~50
iterations in a quotaoff operation:

[ 8872.301115] xfs_quota       D13888 92262  91813 0x00004002
[ 8872.302538] Call Trace:
[ 8872.303193]  __schedule+0x2d2/0x780
[ 8872.304108]  ? do_raw_spin_unlock+0x57/0xd0
[ 8872.305198]  schedule+0x6e/0xe0
[ 8872.306021]  schedule_timeout+0x14d/0x300
[ 8872.307060]  ? __next_timer_interrupt+0xe0/0xe0
[ 8872.308231]  ? xfs_qm_dqusage_adjust+0x200/0x200
[ 8872.309422]  schedule_timeout_uninterruptible+0x2a/0x30
[ 8872.310759]  xfs_qm_dquot_walk.isra.0+0x15a/0x1b0
[ 8872.311971]  xfs_qm_dqpurge_all+0x7f/0x90
[ 8872.313022]  xfs_qm_scall_quotaoff+0x18d/0x2b0
[ 8872.314163]  xfs_quota_disable+0x3a/0x60
[ 8872.315179]  kernel_quotactl+0x7e2/0x8d0
[ 8872.316196]  ? __do_sys_newstat+0x51/0x80
[ 8872.317238]  __x64_sys_quotactl+0x1e/0x30
[ 8872.318266]  do_syscall_64+0x46/0x90
[ 8872.319193]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 8872.320490] RIP: 0033:0x7f46b5490f2a
[ 8872.321414] Code: Bad RIP value.

Returning -EAGAIN from xfs_qm_dqpurge() without clearing the
XFS_DQ_FREEING flag means the xfs_qm_dqpurge_all() code can never
free the dquot, and we loop forever waiting for the XFS_DQ_FREEING
flag to go away on the dquot that leaked it via -EAGAIN.

Fixes: 8d3d7e2b35ea ("xfs: trylock underlying buffer on dquot flush")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
---
 fs/xfs/xfs_qm.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/xfs/xfs_qm.c b/fs/xfs/xfs_qm.c
index ef2faee96909..6b23ebd3f54f 100644
--- a/fs/xfs/xfs_qm.c
+++ b/fs/xfs/xfs_qm.c
@@ -148,6 +148,7 @@ xfs_qm_dqpurge(
 			error = xfs_bwrite(bp);
 			xfs_buf_relse(bp);
 		} else if (error == -EAGAIN) {
+			dqp->dq_flags &= ~XFS_DQ_FREEING;
 			goto out_unlock;
 		}
 		xfs_dqflock(dqp);
-- 
2.35.1

[PATCH 5.4 CANDIDATE 3/3] xfs: force the log after remapping a synchronous-writes file

[Chandan Babu R]

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

commit 5ffce3cc22a0e89813ed0c7162a68b639aef9ab6 upstream.

Commit 5833112df7e9 tried to make it so that a remap operation would
force the log out to disk if the filesystem is mounted with mandatory
synchronous writes.  Unfortunately, that commit failed to handle the
case where the inode or the file descriptor require mandatory
synchronous writes.

Refactor the check into into a helper that will look for all three
conditions, and now we can treat reflink just like any other synchronous
write.

Fixes: 5833112df7e9 ("xfs: reflink should force the log out if mounted with wsync")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
---
 fs/xfs/xfs_file.c | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index cbca91b4b5b8..c67fab2c37c5 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -990,6 +990,21 @@ xfs_file_fadvise(
 	return ret;
 }
 
+/* Does this file, inode, or mount want synchronous writes? */
+static inline bool xfs_file_sync_writes(struct file *filp)
+{
+	struct xfs_inode	*ip = XFS_I(file_inode(filp));
+
+	if (ip->i_mount->m_flags & XFS_MOUNT_WSYNC)
+		return true;
+	if (filp->f_flags & (__O_SYNC | O_DSYNC))
+		return true;
+	if (IS_SYNC(file_inode(filp)))
+		return true;
+
+	return false;
+}
+
 STATIC loff_t
 xfs_file_remap_range(
 	struct file		*file_in,
@@ -1047,7 +1062,7 @@ xfs_file_remap_range(
 	if (ret)
 		goto out_unlock;
 
-	if (mp->m_flags & XFS_MOUNT_WSYNC)
+	if (xfs_file_sync_writes(file_in) || xfs_file_sync_writes(file_out))
 		xfs_log_force_inode(dest);
 out_unlock:
 	xfs_reflink_remap_unlock(file_in, file_out);
-- 
2.35.1

Re: [PATCH 5.4 CANDIDATE 0/3] Fixes for patches backported to 5.4.y from v5.7

[Darrick J. Wong]

On Sat, Oct 29, 2022 at 07:27:29PM +0530, Chandan Babu R wrote:
> Hi Darrick,
> 
> Patches backported from v5.7 to 5.4.y had fixes from newer versions of
> Linux kernel. I had missed including these patches in my previous
> patchset posting.
> 
> This patchset has been tested by executing fstests (via kdevops) using
> the following XFS configurations,
> 
> 1. No CRC (with 512 and 4k block size).
> 2. Reflink/Rmapbt (1k and 4k block size).
> 3. Reflink without Rmapbt.
> 4. External log device.

Looks good to me!
Acked-by: Darrick J. Wong <djwong@kernel.org>

--D

> 
> Brian Foster (1):
>   xfs: finish dfops on every insert range shift iteration
> 
> Darrick J. Wong (2):
>   xfs: clear XFS_DQ_FREEING if we can't lock the dquot buffer to flush
>   xfs: force the log after remapping a synchronous-writes file
> 
>  fs/xfs/xfs_bmap_util.c |  2 +-
>  fs/xfs/xfs_file.c      | 17 ++++++++++++++++-
>  fs/xfs/xfs_qm.c        |  1 +
>  3 files changed, 18 insertions(+), 2 deletions(-)
> 
> -- 
> 2.35.1
>