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authorDave Chinner <dchinner@redhat.com>2010-08-24 11:42:52 +1000
committerDave Chinner <david@fromorbit.com>2010-08-24 11:42:52 +1000
commitd17c701ce6a548a92f7f8a3cec20299465f36ee3 (patch)
tree26a4e52b998edf3762baea43c0d9755118240c8d
parent76be97c1fc945db08aae1f1b746012662d643e97 (diff)
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xfs: unlock items before allowing the CIL to commit
When we commit a transaction using delayed logging, we need to unlock the items in the transaciton before we unlock the CIL context and allow it to be checkpointed. If we unlock them after we release the CIl context lock, the CIL can checkpoint and complete before we free the log items. This breaks stale buffer item unlock and unpin processing as there is an implicit assumption that the unlock will occur before the unpin. Also, some log items need to store the LSN of the transaction commit in the item (inodes and EFIs) and so can race with other transaction completions if we don't prevent the CIL from checkpointing before the unlock occurs. Cc: <stable@kernel.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
-rw-r--r--fs/xfs/xfs_log_cil.c14
-rw-r--r--fs/xfs/xfs_trans.c5
-rw-r--r--fs/xfs/xfs_trans_priv.h3
3 files changed, 17 insertions, 5 deletions
diff --git a/fs/xfs/xfs_log_cil.c b/fs/xfs/xfs_log_cil.c
index 31e4ea2d19ac..ef8e7d9f445d 100644
--- a/fs/xfs/xfs_log_cil.c
+++ b/fs/xfs/xfs_log_cil.c
@@ -377,9 +377,23 @@ xfs_log_commit_cil(
xfs_log_done(mp, tp->t_ticket, NULL, log_flags);
xfs_trans_unreserve_and_mod_sb(tp);
+ /*
+ * Once all the items of the transaction have been copied to the CIL,
+ * the items can be unlocked and freed.
+ *
+ * This needs to be done before we drop the CIL context lock because we
+ * have to update state in the log items and unlock them before they go
+ * to disk. If we don't, then the CIL checkpoint can race with us and
+ * we can run checkpoint completion before we've updated and unlocked
+ * the log items. This affects (at least) processing of stale buffers,
+ * inodes and EFIs.
+ */
+ xfs_trans_free_items(tp, *commit_lsn, 0);
+
/* check for background commit before unlock */
if (log->l_cilp->xc_ctx->space_used > XLOG_CIL_SPACE_LIMIT(log))
push = 1;
+
up_read(&log->l_cilp->xc_ctx_lock);
/*
diff --git a/fs/xfs/xfs_trans.c b/fs/xfs/xfs_trans.c
index fdca7416c754..1c47edaea0d2 100644
--- a/fs/xfs/xfs_trans.c
+++ b/fs/xfs/xfs_trans.c
@@ -1167,7 +1167,7 @@ xfs_trans_del_item(
* Unlock all of the items of a transaction and free all the descriptors
* of that transaction.
*/
-STATIC void
+void
xfs_trans_free_items(
struct xfs_trans *tp,
xfs_lsn_t commit_lsn,
@@ -1653,9 +1653,6 @@ xfs_trans_commit_cil(
return error;
current_restore_flags_nested(&tp->t_pflags, PF_FSTRANS);
-
- /* xfs_trans_free_items() unlocks them first */
- xfs_trans_free_items(tp, *commit_lsn, 0);
xfs_trans_free(tp);
return 0;
}
diff --git a/fs/xfs/xfs_trans_priv.h b/fs/xfs/xfs_trans_priv.h
index e2d93d8ead7b..62da86c90de5 100644
--- a/fs/xfs/xfs_trans_priv.h
+++ b/fs/xfs/xfs_trans_priv.h
@@ -25,7 +25,8 @@ struct xfs_trans;
void xfs_trans_add_item(struct xfs_trans *, struct xfs_log_item *);
void xfs_trans_del_item(struct xfs_log_item *);
-
+void xfs_trans_free_items(struct xfs_trans *tp, xfs_lsn_t commit_lsn,
+ int flags);
void xfs_trans_item_committed(struct xfs_log_item *lip,
xfs_lsn_t commit_lsn, int aborted);
void xfs_trans_unreserve_and_mod_sb(struct xfs_trans *tp);