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authorDave Chinner <dchinner@redhat.com>2022-03-29 18:22:01 -0700
committerDarrick J. Wong <djwong@kernel.org>2022-03-29 18:22:01 -0700
commit41e6362183589afd2cd51d653e277d256daab11f (patch)
treed5c81c32d5893b00fc1a01802980b9eb329a3745 /fs/xfs
parentb5f17bec1213a3ed2f4d79ad4c566e00cabe2a9b (diff)
xfs: xfs_do_force_shutdown needs to block racing shutdowns
When we call xfs_forced_shutdown(), the caller often expects the filesystem to be completely shut down when it returns. However, if we have racing xfs_forced_shutdown() calls, the first caller sets the mount shutdown flag then goes to shutdown the log. The second caller sees the mount shutdown flag and returns immediately - it does not wait for the log to be shut down. Unfortunately, xfs_forced_shutdown() is used in some places that expect it to completely shut down the filesystem before it returns (e.g. xfs_trans_log_inode()). As such, returning before the log has been shut down leaves us in a place where the transaction failed to complete correctly but we still call xfs_trans_commit(). This situation arises because xfs_trans_log_inode() does not return an error and instead calls xfs_force_shutdown() to ensure that the transaction being committed is aborted. Unfortunately, we have a race condition where xfs_trans_commit() needs to check xlog_is_shutdown() because it can't abort log items before the log is shut down, but it needs to use xfs_is_shutdown() because xfs_forced_shutdown() does not block waiting for the log to shut down. To fix this conundrum, first we make all calls to xfs_forced_shutdown() block until the log is also shut down. This means we can then safely use xfs_forced_shutdown() as a mechanism that ensures the currently running transaction will be aborted by xfs_trans_commit() regardless of the shutdown check it uses. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <djwong@kernel.org> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Diffstat (limited to 'fs/xfs')
-rw-r--r--fs/xfs/xfs_fsops.c6
-rw-r--r--fs/xfs/xfs_log.c1
-rw-r--r--fs/xfs/xfs_log_priv.h11
3 files changed, 17 insertions, 1 deletions
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 196e2c51309c..68f74549fa22 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -17,6 +17,7 @@
#include "xfs_fsops.h"
#include "xfs_trans_space.h"
#include "xfs_log.h"
+#include "xfs_log_priv.h"
#include "xfs_ag.h"
#include "xfs_ag_resv.h"
#include "xfs_trace.h"
@@ -518,8 +519,11 @@ xfs_do_force_shutdown(
int tag;
const char *why;
- if (test_and_set_bit(XFS_OPSTATE_SHUTDOWN, &mp->m_opstate))
+
+ if (test_and_set_bit(XFS_OPSTATE_SHUTDOWN, &mp->m_opstate)) {
+ xlog_shutdown_wait(mp->m_log);
return;
+ }
if (mp->m_sb_bp)
mp->m_sb_bp->b_flags |= XBF_DONE;
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index 4188ed752169..678ca01047e1 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -3923,6 +3923,7 @@ xlog_force_shutdown(
xlog_state_shutdown_callbacks(log);
spin_unlock(&log->l_icloglock);
+ wake_up_var(&log->l_opstate);
return log_error;
}
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index 23103d68423c..cd0508e26fec 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -484,6 +484,17 @@ xlog_is_shutdown(struct xlog *log)
return test_bit(XLOG_IO_ERROR, &log->l_opstate);
}
+/*
+ * Wait until the xlog_force_shutdown() has marked the log as shut down
+ * so xlog_is_shutdown() will always return true.
+ */
+static inline void
+xlog_shutdown_wait(
+ struct xlog *log)
+{
+ wait_var_event(&log->l_opstate, xlog_is_shutdown(log));
+}
+
/* common routines */
extern int
xlog_recover(