When a buffer has been failed during writeback, the inode items into it
are kept flush locked, and are never resubmitted due the flush lock, so,
if any buffer fails to be written, the items in AIL are never written to
disk and never unlocked.
This causes a filesystem to be unmountable due these items flush locked
in AIL, but this also causes the items in AIL to never be written back,
even when the IO device comes back to normal.
I've been testing this patch with a DM-thin device, creating a
filesystem larger than the real device.
When writing enough data to fill the DM-thin device, XFS receives ENOSPC
errors from the device, and keep spinning on xfsaild (when 'retry
forever' configuration is set).
At this point, the filesystem is unmountable because of the flush locked
items in AIL, but worse, the items in AIL are never retried at all
(once xfs_inode_item_push() will skip the items that are flush locked),
even if the underlying DM-thin device is expanded to the proper size.
This patch fixes both cases, retrying any item that has been failed
previously, using the infra-structure provided by the previous patch.
Signed-off-by: Carlos Maiolino <cmaiolino@xxxxxxxxxx>
---
This same problem is also possible in dquot code, but the fix is almost
identical.
I am not submitting a fix for dquot yet to avoid the need to create VX for both
patches, once we agree with the solution, I'll submit a fix to dquot.
fs/xfs/xfs_inode_item.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 53 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_inode_item.c b/fs/xfs/xfs_inode_item.c
index 08cb7d1..583fa9e 100644
--- a/fs/xfs/xfs_inode_item.c
+++ b/fs/xfs/xfs_inode_item.c
@@ -475,6 +475,21 @@ xfs_inode_item_unpin(
wake_up_bit(&ip->i_flags, __XFS_IPINNED_BIT);
}
+STATIC void
+xfs_inode_item_error(
+ struct xfs_log_item *lip,
+ unsigned int bflags)
+{
+
+ /*
+ * The buffer writeback containing this inode has been failed
+ * mark it as failed and unlock the flush lock, so it can be retried
+ * again
+ */
+ if (bflags & XBF_WRITE_FAIL)
+ lip->li_flags |= XFS_LI_FAILED;
+}
+
STATIC uint
xfs_inode_item_push(
struct xfs_log_item *lip,
@@ -517,8 +532,44 @@ xfs_inode_item_push(
* the AIL.
*/
if (!xfs_iflock_nowait(ip)) {
+ if (lip->li_flags & XFS_LI_FAILED) {
+
+ struct xfs_dinode *dip;
+ struct xfs_log_item *next;
+ int error;
+
+ error = xfs_imap_to_bp(ip->i_mount, NULL, &ip->i_imap,
+ &dip, &bp, XBF_TRYLOCK, 0);
+
+ if (error) {
+ rval = XFS_ITEM_FLUSHING;
+ goto out_unlock;
+ }
+
+ if (!(bp->b_flags & XBF_WRITE_FAIL)) {
+ rval = XFS_ITEM_FLUSHING;
+ xfs_buf_relse(bp);
+ goto out_unlock;
+ }
+
+ while (lip != NULL) {
+ next = lip->li_bio_list;
+
+ if (lip->li_flags & XFS_LI_FAILED)
+ lip->li_flags &= XFS_LI_FAILED;
+ lip = next;
+ }
+
+ if (!xfs_buf_delwri_queue(bp, buffer_list))
+ rval = XFS_ITEM_FLUSHING;
+
+ xfs_buf_relse(bp);
+ goto out_unlock;
+ }
+
rval = XFS_ITEM_FLUSHING;
goto out_unlock;
+
}
ASSERT(iip->ili_fields != 0 || XFS_FORCED_SHUTDOWN(ip->i_mount));
@@ -622,7 +673,8 @@ static const struct xfs_item_ops xfs_inode_item_ops = {
.iop_unlock = xfs_inode_item_unlock,
.iop_committed = xfs_inode_item_committed,
.iop_push = xfs_inode_item_push,
- .iop_committing = xfs_inode_item_committing
+ .iop_committing = xfs_inode_item_committing,
+ .iop_error = xfs_inode_item_error
};
--
2.9.3
--
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