diff options
| author | Dave Chinner <dchinner@redhat.com> | 2022-03-29 18:22:01 -0700 |
|---|---|---|
| committer | Darrick J. Wong <djwong@kernel.org> | 2022-03-29 18:22:01 -0700 |
| commit | 41e6362183589afd2cd51d653e277d256daab11f (patch) | |
| tree | d5c81c32d5893b00fc1a01802980b9eb329a3745 /fs/xfs | |
| parent | b5f17bec1213a3ed2f4d79ad4c566e00cabe2a9b (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.c | 6 | ||||
| -rw-r--r-- | fs/xfs/xfs_log.c | 1 | ||||
| -rw-r--r-- | fs/xfs/xfs_log_priv.h | 11 |
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( |