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authorBrian Foster <bfoster@redhat.com>2016-01-04 23:41:16 +0300
committerDave Chinner <david@fromorbit.com>2016-01-04 23:41:16 +0300
commit609adfc2ed5ba16700f125da0b656248bd9d4316 (patch)
tree6612e2f6a7d93cfeeb806abe25def385943544d3 /fs/xfs/xfs_log_priv.h
parent7088c4136fa1cba26531fde40bdcfcf3d2ccd533 (diff)
downloadlinux-609adfc2ed5ba16700f125da0b656248bd9d4316.tar.xz
xfs: debug mode log record crc error injection
XFS now uses CRC verification over a limited section of the log to detect torn writes prior to a crash. This is difficult to test directly due to the timing and hardware requirements to cause a short write. Add a mechanism to inject CRC errors into log records to facilitate testing torn write detection during log recovery. This mechanism is dangerous and can result in filesystem corruption. Thus, it is only available in DEBUG mode for testing/development purposes. Set a non-zero value to the following sysfs entry to enable error injection: /sys/fs/xfs/<dev>/log/log_badcrc_factor Once enabled, XFS intentionally writes an invalid CRC to a log record at some random point in the future based on the provided frequency. The filesystem immediately shuts down once the record has been written to the physical log to prevent metadata writeback (e.g., AIL insertion) once the log write completes. This helps reasonably simulate a torn write to the log as the affected record must be safe to discard. The next mount after the intentional shutdown requires log recovery and should detect and recover from the torn write. Note again that this _will_ result in data loss or worse. For testing and development purposes only! Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/xfs_log_priv.h')
-rw-r--r--fs/xfs/xfs_log_priv.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/xfs/xfs_log_priv.h b/fs/xfs/xfs_log_priv.h
index 8daba7491b13..ed8896310c00 100644
--- a/fs/xfs/xfs_log_priv.h
+++ b/fs/xfs/xfs_log_priv.h
@@ -62,6 +62,7 @@ static inline uint xlog_get_client_id(__be32 i)
#define XLOG_STATE_CALLBACK 0x0020 /* Callback functions now */
#define XLOG_STATE_DIRTY 0x0040 /* Dirty IC log, not ready for ACTIVE status*/
#define XLOG_STATE_IOERROR 0x0080 /* IO error happened in sync'ing log */
+#define XLOG_STATE_IOABORT 0x0100 /* force abort on I/O completion (debug) */
#define XLOG_STATE_ALL 0x7FFF /* All possible valid flags */
#define XLOG_STATE_NOTUSED 0x8000 /* This IC log not being used */
@@ -410,6 +411,8 @@ struct xlog {
/* The following field are used for debugging; need to hold icloglock */
#ifdef DEBUG
void *l_iclog_bak[XLOG_MAX_ICLOGS];
+ /* log record crc error injection factor */
+ uint32_t l_badcrc_factor;
#endif
};