1 files changed, 63 insertions, 69 deletions

diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 931e8e23f19..9c3651c9e75 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -41,6 +41,7 @@
 #include "xfs_trans_priv.h"
 #include "xfs_quota.h"
 #include "xfs_utils.h"
+#include "xfs_cksum.h"
 #include "xfs_trace.h"
 #include "xfs_icache.h"
 
@@ -3216,80 +3217,58 @@ xlog_recover_process_iunlinks(
         mp->m_dmevmask = mp_dmevmask;
 }
 
-
-#ifdef DEBUG
-STATIC void
-xlog_pack_data_checksum(
-        struct xlog             *log,
-        struct xlog_in_core     *iclog,
-        int                     size)
-{
-        int             i;
-        __be32          *up;
-        uint            chksum = 0;
-
-        up = (__be32 *)iclog->ic_datap;
-        /* divide length by 4 to get # words */
-        for (i = 0; i < (size >> 2); i++) {
-                chksum ^= be32_to_cpu(*up);
-                up++;
-        }
-        iclog->ic_header.h_chksum = cpu_to_be32(chksum);
-}
-#else
-#define xlog_pack_data_checksum(log, iclog, size)
-#endif
-
 /*
- * Stamp cycle number in every block
+ * Upack the log buffer data and crc check it. If the check fails, issue a
+ * warning if and only if the CRC in the header is non-zero. This makes the
+ * check an advisory warning, and the zero CRC check will prevent failure
+ * warnings from being emitted when upgrading the kernel from one that does not
+ * add CRCs by default.
+ *
+ * When filesystems are CRC enabled, this CRC mismatch becomes a fatal log
+ * corruption failure
  */
-void
-xlog_pack_data(
-        struct xlog             *log,
-        struct xlog_in_core     *iclog,
-        int                     roundoff)
+STATIC int
+xlog_unpack_data_crc(
+        struct xlog_rec_header  *rhead,
+        xfs_caddr_t             dp,
+        struct xlog             *log)
 {
-        int                     i, j, k;
-        int                     size = iclog->ic_offset + roundoff;
-        __be32                  cycle_lsn;
-        xfs_caddr_t             dp;
-
-        xlog_pack_data_checksum(log, iclog, size);
-
-        cycle_lsn = CYCLE_LSN_DISK(iclog->ic_header.h_lsn);
-
-        dp = iclog->ic_datap;
-        for (i = 0; i < BTOBB(size) &&
-                i < (XLOG_HEADER_CYCLE_SIZE / BBSIZE); i++) {
-                iclog->ic_header.h_cycle_data[i] = *(__be32 *)dp;
-                *(__be32 *)dp = cycle_lsn;
-                dp += BBSIZE;
-        }
-
-        if (xfs_sb_version_haslogv2(&log->l_mp->m_sb)) {
-                xlog_in_core_2_t *xhdr = iclog->ic_data;
-
-                for ( ; i < BTOBB(size); i++) {
-                        j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
-                        k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
-                        xhdr[j].hic_xheader.xh_cycle_data[k] = *(__be32 *)dp;
-                        *(__be32 *)dp = cycle_lsn;
-                        dp += BBSIZE;
+        __be32                  crc;
+
+        crc = xlog_cksum(log, rhead, dp, be32_to_cpu(rhead->h_len));
+        if (crc != rhead->h_crc) {
+                if (rhead->h_crc || xfs_sb_version_hascrc(&log->l_mp->m_sb)) {
+                        xfs_alert(log->l_mp,
+                "log record CRC mismatch: found 0x%x, expected 0x%x.\n",
+                                        be32_to_cpu(rhead->h_crc),
+                                        be32_to_cpu(crc));
+                        xfs_hex_dump(dp, 32);
                 }
 
-                for (i = 1; i < log->l_iclog_heads; i++) {
-                        xhdr[i].hic_xheader.xh_cycle = cycle_lsn;
-                }
+                /*
+                 * If we've detected a log record corruption, then we can't
+                 * recover past this point. Abort recovery if we are enforcing
+                 * CRC protection by punting an error back up the stack.
+                 */
+                if (xfs_sb_version_hascrc(&log->l_mp->m_sb))
+                        return EFSCORRUPTED;
         }
+
+        return 0;
 }
 
-STATIC void
+STATIC int
 xlog_unpack_data(
         struct xlog_rec_header  *rhead,
         xfs_caddr_t             dp,
         struct xlog             *log)
 {
         int                     i, j, k;
+        int                     error;
+
+        error = xlog_unpack_data_crc(rhead, dp, log);
+        if (error)
+                return error;
 
         for (i = 0; i < BTOBB(be32_to_cpu(rhead->h_len)) &&
                   i < (XLOG_HEADER_CYCLE_SIZE / BBSIZE); i++) {
@@ -3306,6 +3285,8 @@ xlog_unpack_data(
                         dp += BBSIZE;
                 }
         }
+
+        return 0;
 }
 
 STATIC int
@@ -3437,9 +3418,13 @@ xlog_do_recovery_pass(
                         if (error)
                                 goto bread_err2;
 
-                        xlog_unpack_data(rhead, offset, log);
-                        if ((error = xlog_recover_process_data(log,
-                                                rhash, rhead, offset, pass)))
+                        error = xlog_unpack_data(rhead, offset, log);
+                        if (error)
+                                goto bread_err2;
+
+                        error = xlog_recover_process_data(log,
+                                                rhash, rhead, offset, pass);
+                        if (error)
                                 goto bread_err2;
                         blk_no += bblks + hblks;
                 }
@@ -3549,9 +3534,14 @@ xlog_do_recovery_pass(
                                 if (error)
                                         goto bread_err2;
                         }
-                        xlog_unpack_data(rhead, offset, log);
-                        if ((error = xlog_recover_process_data(log, rhash,
-                                                        rhead, offset, pass)))
+
+                        error = xlog_unpack_data(rhead, offset, log);
+                        if (error)
+                                goto bread_err2;
+
+                        error = xlog_recover_process_data(log, rhash,
+                                                        rhead, offset, pass);
+                        if (error)
                                 goto bread_err2;
                         blk_no += bblks;
                 }
@@ -3576,9 +3566,13 @@ xlog_do_recovery_pass(
                         if (error)
                                 goto bread_err2;
 
-                        xlog_unpack_data(rhead, offset, log);
-                        if ((error = xlog_recover_process_data(log, rhash,
-                                                        rhead, offset, pass)))
+                        error = xlog_unpack_data(rhead, offset, log);
+                        if (error)
+                                goto bread_err2;
+
+                        error = xlog_recover_process_data(log, rhash,
+                                                        rhead, offset, pass);
+                        if (error)
                                 goto bread_err2;
                         blk_no += bblks + hblks;
                 }