* consistent. We don't do an unmount here; just shutdown the shop, make sure
* that absolutely nothing persistent happens to this filesystem after this
* point.
+ *
+ * The shutdown state change is atomic, resulting in the first and only the
+ * first shutdown call processing the shutdown. This means we only shutdown the
+ * log once as it requires, and we don't spam the logs when multiple concurrent
+ * shutdowns race to set the shutdown flags.
*/
void
xfs_do_force_shutdown(
char *fname,
int lnnum)
{
- bool logerror = flags & SHUTDOWN_LOG_IO_ERROR;
+ int tag;
+ const char *why;
- /*
- * No need to duplicate efforts.
- */
- if (XFS_FORCED_SHUTDOWN(mp) && !logerror)
- return;
-
- /*
- * This flags XFS_MOUNT_FS_SHUTDOWN, makes sure that we don't
- * queue up anybody new on the log reservations, and wakes up
- * everybody who's sleeping on log reservations to tell them
- * the bad news.
- */
- if (xfs_log_force_umount(mp, logerror))
- return;
-
- if (flags & SHUTDOWN_FORCE_UMOUNT) {
- xfs_alert(mp,
-"User initiated shutdown (0x%x) received. Shutting down filesystem",
- flags);
+ spin_lock(&mp->m_sb_lock);
+ if (XFS_FORCED_SHUTDOWN(mp)) {
+ spin_unlock(&mp->m_sb_lock);
return;
}
+ mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
+ if (mp->m_sb_bp)
+ mp->m_sb_bp->b_flags |= XBF_DONE;
+ spin_unlock(&mp->m_sb_lock);
+
+ if (flags & SHUTDOWN_FORCE_UMOUNT)
+ xfs_alert(mp, "User initiated shutdown received.");
- if (flags & SHUTDOWN_CORRUPT_INCORE) {
- xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_CORRUPT,
-"Corruption of in-memory data (0x%x) detected at %pS (%s:%d). Shutting down filesystem",
- flags, __return_address, fname, lnnum);
- if (XFS_ERRLEVEL_HIGH <= xfs_error_level)
- xfs_stack_trace();
- } else if (logerror) {
- xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_LOGERROR,
-"Log I/O error (0x%x) detected at %pS (%s:%d). Shutting down filesystem",
- flags, __return_address, fname, lnnum);
+ if (xlog_force_shutdown(mp->m_log, flags)) {
+ tag = XFS_PTAG_SHUTDOWN_LOGERROR;
+ why = "Log I/O Error";
+ } else if (flags & SHUTDOWN_CORRUPT_INCORE) {
+ tag = XFS_PTAG_SHUTDOWN_CORRUPT;
+ why = "Corruption of in-memory data";
} else {
- xfs_alert_tag(mp, XFS_PTAG_SHUTDOWN_IOERROR,
-"I/O error (0x%x) detected at %pS (%s:%d). Shutting down filesystem",
- flags, __return_address, fname, lnnum);
+ tag = XFS_PTAG_SHUTDOWN_IOERROR;
+ why = "Metadata I/O Error";
}
+ xfs_alert_tag(mp, tag,
+"%s (0x%x) detected at %pS (%s:%d). Shutting down filesystem.",
+ why, flags, __return_address, fname, lnnum);
xfs_alert(mp,
"Please unmount the filesystem and rectify the problem(s)");
+ if (xfs_error_level >= XFS_ERRLEVEL_HIGH)
+ xfs_stack_trace();
}
/*
#endif
/*
- * This is called from xfs_force_shutdown, when we're forcibly
- * shutting down the filesystem, typically because of an IO error.
- * Our main objectives here are to make sure that:
- * a. if !logerror, flush the logs to disk. Anything modified
- * after this is ignored.
- * b. the filesystem gets marked 'SHUTDOWN' for all interested
- * parties to find out, 'atomically'.
- * c. those who're sleeping on log reservations, pinned objects and
- * other resources get woken up, and be told the bad news.
- * d. nothing new gets queued up after (b) and (c) are done.
+ * Perform a forced shutdown on the log. This should be called once and once
+ * only by the high level filesystem shutdown code to shut the log subsystem
+ * down cleanly.
*
- * Note: for the !logerror case we need to flush the regions held in memory out
- * to disk first. This needs to be done before the log is marked as shutdown,
- * otherwise the iclog writes will fail.
+ * Our main objectives here are to make sure that:
+ * a. if the shutdown was not due to a log IO error, flush the logs to
+ * disk. Anything modified after this is ignored.
+ * b. the log gets atomically marked 'XLOG_IO_ERROR' for all interested
+ * parties to find out. Nothing new gets queued after this is done.
+ * c. Tasks sleeping on log reservations, pinned objects and
+ * other resources get woken up.
*
- * Return non-zero if log shutdown transition had already happened.
+ * Return true if the shutdown cause was a log IO error and we actually shut the
+ * log down.
*/
-int
-xfs_log_force_umount(
- struct xfs_mount *mp,
- int logerror)
+bool
+xlog_force_shutdown(
+ struct xlog *log,
+ int shutdown_flags)
{
- struct xlog *log;
- int retval = 0;
-
- log = mp->m_log;
+ bool log_error = (shutdown_flags & SHUTDOWN_LOG_IO_ERROR);
/*
- * If this happens during log recovery, don't worry about
- * locking; the log isn't open for business yet.
+ * If this happens during log recovery then we aren't using the runtime
+ * log mechanisms yet so there's nothing to shut down.
*/
- if (!log || xlog_in_recovery(log)) {
- mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
- if (mp->m_sb_bp)
- mp->m_sb_bp->b_flags |= XBF_DONE;
- return 0;
- }
+ if (!log || xlog_in_recovery(log))
+ return false;
- /*
- * Somebody could've already done the hard work for us.
- * No need to get locks for this.
- */
- if (logerror && xlog_is_shutdown(log))
- return 1;
+ ASSERT(!xlog_is_shutdown(log));
/*
* Flush all the completed transactions to disk before marking the log
- * being shut down. We need to do it in this order to ensure that
- * completed operations are safely on disk before we shut down, and that
- * we don't have to issue any buffer IO after the shutdown flags are set
- * to guarantee this.
+ * being shut down. We need to do this first as shutting down the log
+ * before the force will prevent the log force from flushing the iclogs
+ * to disk.
+ *
+ * Re-entry due to a log IO error shutdown during the log force is
+ * prevented by the atomicity of higher level shutdown code.
*/
- if (!logerror)
- xfs_log_force(mp, XFS_LOG_SYNC);
+ if (!log_error)
+ xfs_log_force(log->l_mp, XFS_LOG_SYNC);
/*
- * mark the filesystem and the as in a shutdown state and wake
- * everybody up to tell them the bad news.
+ * Atomically set the shutdown state. If the shutdown state is already
+ * set, there someone else is performing the shutdown and so we are done
+ * here. This should never happen because we should only ever get called
+ * once by the first shutdown caller.
+ *
+ * Much of the log state machine transitions assume that shutdown state
+ * cannot change once they hold the log->l_icloglock. Hence we need to
+ * hold that lock here, even though we use the atomic test_and_set_bit()
+ * operation to set the shutdown state.
*/
spin_lock(&log->l_icloglock);
- mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
- if (mp->m_sb_bp)
- mp->m_sb_bp->b_flags |= XBF_DONE;
-
- /*
- * Mark the log and the iclogs with IO error flags to prevent any
- * further log IO from being issued or completed.
- */
- if (!test_and_set_bit(XLOG_IO_ERROR, &log->l_opstate))
- retval = 1;
+ if (test_and_set_bit(XLOG_IO_ERROR, &log->l_opstate)) {
+ spin_unlock(&log->l_icloglock);
+ ASSERT(0);
+ return false;
+ }
spin_unlock(&log->l_icloglock);
/*
spin_unlock(&log->l_cilp->xc_push_lock);
xlog_state_do_callback(log);
- return retval;
+ return log_error;
}
STATIC int
projects / users / dwmw2 / linux.git / commitdiff