5 files changed, 91 insertions, 27 deletions

diff --git a/fs/xfs/xfs_ag.h b/fs/xfs/xfs_ag.h
index f2aeedb6a579..9f4815e0c96f 100644
--- a/fs/xfs/xfs_ag.h
+++ b/fs/xfs/xfs_ag.h
@@ -63,12 +63,29 @@ typedef struct xfs_agf {
         __be32          agf_spare0;     /* spare field */
         __be32          agf_levels[XFS_BTNUM_AGF];      /* btree levels */
         __be32          agf_spare1;     /* spare field */
+
         __be32          agf_flfirst;    /* first freelist block's index */
         __be32          agf_fllast;     /* last freelist block's index */
         __be32          agf_flcount;    /* count of blocks in freelist */
         __be32          agf_freeblks;   /* total free blocks */
+
         __be32          agf_longest;    /* longest free space */
         __be32          agf_btreeblks;  /* # of blocks held in AGF btrees */
+        uuid_t          agf_uuid;       /* uuid of filesystem */
+
+        /*
+         * reserve some contiguous space for future logged fields before we add
+         * the unlogged fields. This makes the range logging via flags and
+         * structure offsets much simpler.
+         */
+        __be64          agf_spare64[16];
+
+        /* unlogged fields, written during buffer writeback. */
+        __be64          agf_lsn;        /* last write sequence */
+        __be32          agf_crc;        /* crc of agf sector */
+        __be32          agf_spare2;
+
+        /* structure must be padded to 64 bit alignment */
 } xfs_agf_t;
 
 #define XFS_AGF_MAGICNUM        0x00000001
@@ -83,7 +100,8 @@ typedef struct xfs_agf {
 #define XFS_AGF_FREEBLKS        0x00000200
 #define XFS_AGF_LONGEST         0x00000400
 #define XFS_AGF_BTREEBLKS       0x00000800
-#define XFS_AGF_NUM_BITS        12
+#define XFS_AGF_UUID            0x00001000
+#define XFS_AGF_NUM_BITS        13
 #define XFS_AGF_ALL_BITS        ((1 << XFS_AGF_NUM_BITS) - 1)
 
 #define XFS_AGF_FLAGS \
@@ -98,7 +116,8 @@ typedef struct xfs_agf {
         { XFS_AGF_FLCOUNT,      "FLCOUNT" }, \
         { XFS_AGF_FREEBLKS,     "FREEBLKS" }, \
         { XFS_AGF_LONGEST,      "LONGEST" }, \
-        { XFS_AGF_BTREEBLKS,    "BTREEBLKS" }
+        { XFS_AGF_BTREEBLKS,    "BTREEBLKS" }, \
+        { XFS_AGF_UUID,         "UUID" }
 
 /* disk block (xfs_daddr_t) in the AG */
 #define XFS_AGF_DADDR(mp)       ((xfs_daddr_t)(1 << (mp)->m_sectbb_log))
diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index a8beb5c7dd60..c34f799aa92e 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -33,7 +33,9 @@
 #include "xfs_alloc.h"
 #include "xfs_extent_busy.h"
 #include "xfs_error.h"
+#include "xfs_cksum.h"
 #include "xfs_trace.h"
+#include "xfs_buf_item.h"
 
 struct workqueue_struct *xfs_alloc_wq;
 
@@ -2058,11 +2060,14 @@ xfs_alloc_log_agf(
                 offsetof(xfs_agf_t, agf_freeblks),
                 offsetof(xfs_agf_t, agf_longest),
                 offsetof(xfs_agf_t, agf_btreeblks),
+                offsetof(xfs_agf_t, agf_uuid),
                 sizeof(xfs_agf_t)
         };
 
         trace_xfs_agf(tp->t_mountp, XFS_BUF_TO_AGF(bp), fields, _RET_IP_);
 
+        xfs_trans_buf_set_type(tp, bp, XFS_BLF_AGF_BUF);
+
         xfs_btree_offsets(fields, offsets, XFS_AGF_NUM_BITS, &first, &last);
         xfs_trans_log_buf(tp, bp, (uint)first, (uint)last);
 }
@@ -2143,22 +2148,24 @@ xfs_alloc_put_freelist(
         return 0;
 }
 
-static void
+static bool
 xfs_agf_verify(
+        struct xfs_mount *mp,
         struct xfs_buf  *bp)
  {
-        struct xfs_mount *mp = bp->b_target->bt_mount;
-        struct xfs_agf  *agf;
-        int             agf_ok;
+        struct xfs_agf  *agf = XFS_BUF_TO_AGF(bp);
 
-        agf = XFS_BUF_TO_AGF(bp);
+        if (xfs_sb_version_hascrc(&mp->m_sb) &&
+            !uuid_equal(&agf->agf_uuid, &mp->m_sb.sb_uuid))
+                        return false;
 
-        agf_ok = agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
-                XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
-                be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
-                be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
-                be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
-                be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp);
+        if (!(agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
+              XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
+              be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
+              be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
+              be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
+              be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp)))
+                return false;
 
         /*
          * during growfs operations, the perag is not fully initialised,
@@ -2166,33 +2173,58 @@ xfs_agf_verify(
          * use it by using uncached buffers that don't have the perag attached
          * so we can detect and avoid this problem.
          */
-        if (bp->b_pag)
-                agf_ok = agf_ok && be32_to_cpu(agf->agf_seqno) ==
-                                                bp->b_pag->pag_agno;
+        if (bp->b_pag && be32_to_cpu(agf->agf_seqno) != bp->b_pag->pag_agno)
+                return false;
 
-        if (xfs_sb_version_haslazysbcount(&mp->m_sb))
-                agf_ok = agf_ok && be32_to_cpu(agf->agf_btreeblks) <=
-                                                be32_to_cpu(agf->agf_length);
+        if (xfs_sb_version_haslazysbcount(&mp->m_sb) &&
+            be32_to_cpu(agf->agf_btreeblks) > be32_to_cpu(agf->agf_length))
+                return false;
+
+        return true;;
 
-        if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
-                        XFS_RANDOM_ALLOC_READ_AGF))) {
-                XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, agf);
-                xfs_buf_ioerror(bp, EFSCORRUPTED);
-        }
 }
 
 static void
 xfs_agf_read_verify(
         struct xfs_buf  *bp)
 {
-        xfs_agf_verify(bp);
+        struct xfs_mount *mp = bp->b_target->bt_mount;
+        int             agf_ok = 1;
+
+        if (xfs_sb_version_hascrc(&mp->m_sb))
+                agf_ok = xfs_verify_cksum(bp->b_addr, BBTOB(bp->b_length),
+                                          offsetof(struct xfs_agf, agf_crc));
+
+        agf_ok = agf_ok && xfs_agf_verify(mp, bp);
+
+        if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
+                        XFS_RANDOM_ALLOC_READ_AGF))) {
+                XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+                xfs_buf_ioerror(bp, EFSCORRUPTED);
+        }
 }
 
 static void
 xfs_agf_write_verify(
         struct xfs_buf  *bp)
 {
-        xfs_agf_verify(bp);
+        struct xfs_mount *mp = bp->b_target->bt_mount;
+        struct xfs_buf_log_item *bip = bp->b_fspriv;
+
+        if (!xfs_agf_verify(mp, bp)) {
+                XFS_CORRUPTION_ERROR(__func__, XFS_ERRLEVEL_LOW, mp, bp->b_addr);
+                xfs_buf_ioerror(bp, EFSCORRUPTED);
+                return;
+        }
+
+        if (!xfs_sb_version_hascrc(&mp->m_sb))
+                return;
+
+        if (bip)
+                XFS_BUF_TO_AGF(bp)->agf_lsn = cpu_to_be64(bip->bli_item.li_lsn);
+
+        xfs_update_cksum(bp->b_addr, BBTOB(bp->b_length),
+                         offsetof(struct xfs_agf, agf_crc));
 }
 
 const struct xfs_buf_ops xfs_agf_buf_ops = {
diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h
index 101ef8377f1b..76bd7a167a70 100644
--- a/fs/xfs/xfs_buf_item.h
+++ b/fs/xfs/xfs_buf_item.h
@@ -45,12 +45,14 @@ extern kmem_zone_t	*xfs_buf_item_zone;
  * once the changes have been replayed into the buffer.
  */
 #define XFS_BLF_BTREE_BUF       (1<<5)
+#define XFS_BLF_AGF_BUF         (1<<6)
 
 #define XFS_BLF_TYPE_MASK       \
                 (XFS_BLF_UDQUOT_BUF | \
                  XFS_BLF_PDQUOT_BUF | \
                  XFS_BLF_GDQUOT_BUF | \
-                 XFS_BLF_BTREE_BUF)
+                 XFS_BLF_BTREE_BUF | \
+                 XFS_BLF_AGF_BUF)
 
 #define XFS_BLF_CHUNK           128
 #define XFS_BLF_SHIFT           7
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c
index 6fe286a8e29b..b6cca27e9132 100644
--- a/fs/xfs/xfs_fsops.c
+++ b/fs/xfs/xfs_fsops.c
@@ -247,6 +247,9 @@ xfs_growfs_data_private(
                 tmpsize = agsize - XFS_PREALLOC_BLOCKS(mp);
                 agf->agf_freeblks = cpu_to_be32(tmpsize);
                 agf->agf_longest = cpu_to_be32(tmpsize);
+                if (xfs_sb_version_hascrc(&mp->m_sb))
+                        uuid_copy(&agf->agf_uuid, &mp->m_sb.sb_uuid);
+
                 error = xfs_bwrite(bp);
                 xfs_buf_relse(bp);
                 if (error)
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 3762ce2e99fc..dadf24566d16 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -1953,6 +1953,14 @@ xlog_recover_do_reg_buffer(
                         break;
                 }
                 break;
+        case XFS_BLF_AGF_BUF:
+                if (*(__be32 *)bp->b_addr != cpu_to_be32(XFS_AGF_MAGIC)) {
+                        xfs_warn(mp, "Bad AGF block magic!");
+                        ASSERT(0);
+                        break;
+                }
+                bp->b_ops = &xfs_agf_buf_ops;
+                break;
         default:
                 break;
         }