[XFS] Avoid replaying inode buffer initialisation log items if on-disk version is newer.
SGI-PV: 969656
SGI-Modid: xfs-linux-melb:xfs-kern:29676a
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
diff --git a/fs/xfs/xfs_buf_item.h b/fs/xfs/xfs_buf_item.h
index d7e1361..fa25b7d 100644
--- a/fs/xfs/xfs_buf_item.h
+++ b/fs/xfs/xfs_buf_item.h
@@ -52,6 +52,11 @@
#define XFS_BLI_UDQUOT_BUF 0x4
#define XFS_BLI_PDQUOT_BUF 0x8
#define XFS_BLI_GDQUOT_BUF 0x10
+/*
+ * This flag indicates that the buffer contains newly allocated
+ * inodes.
+ */
+#define XFS_BLI_INODE_NEW_BUF 0x20
#define XFS_BLI_CHUNK 128
#define XFS_BLI_SHIFT 7
diff --git a/fs/xfs/xfs_log_recover.c b/fs/xfs/xfs_log_recover.c
index 8ae6e8e..dacb197 100644
--- a/fs/xfs/xfs_log_recover.c
+++ b/fs/xfs/xfs_log_recover.c
@@ -1874,6 +1874,7 @@
/*ARGSUSED*/
STATIC void
xlog_recover_do_reg_buffer(
+ xfs_mount_t *mp,
xlog_recover_item_t *item,
xfs_buf_t *bp,
xfs_buf_log_format_t *buf_f)
@@ -1884,6 +1885,50 @@
unsigned int *data_map = NULL;
unsigned int map_size = 0;
int error;
+ int stale_buf = 1;
+
+ /*
+ * Scan through the on-disk inode buffer and attempt to
+ * determine if it has been written to since it was logged.
+ *
+ * - If any of the magic numbers are incorrect then the buffer is stale
+ * - If any of the modes are non-zero then the buffer is not stale
+ * - If all of the modes are zero and at least one of the generation
+ * counts is non-zero then the buffer is stale
+ *
+ * If the end result is a stale buffer then the log buffer is replayed
+ * otherwise it is skipped.
+ *
+ * This heuristic is not perfect. It can be improved by scanning the
+ * entire inode chunk for evidence that any of the inode clusters have
+ * been updated. To fix this problem completely we will need a major
+ * architectural change to the logging system.
+ */
+ if (buf_f->blf_flags & XFS_BLI_INODE_NEW_BUF) {
+ xfs_dinode_t *dip;
+ int inodes_per_buf;
+ int mode_count = 0;
+ int gen_count = 0;
+
+ stale_buf = 0;
+ inodes_per_buf = XFS_BUF_COUNT(bp) >> mp->m_sb.sb_inodelog;
+ for (i = 0; i < inodes_per_buf; i++) {
+ dip = (xfs_dinode_t *)xfs_buf_offset(bp,
+ i * mp->m_sb.sb_inodesize);
+ if (be16_to_cpu(dip->di_core.di_magic) !=
+ XFS_DINODE_MAGIC) {
+ stale_buf = 1;
+ break;
+ }
+ if (be16_to_cpu(dip->di_core.di_mode))
+ mode_count++;
+ if (be16_to_cpu(dip->di_core.di_gen))
+ gen_count++;
+ }
+
+ if (!mode_count && gen_count)
+ stale_buf = 1;
+ }
switch (buf_f->blf_type) {
case XFS_LI_BUF:
@@ -1917,7 +1962,7 @@
-1, 0, XFS_QMOPT_DOWARN,
"dquot_buf_recover");
}
- if (!error)
+ if (!error && stale_buf)
memcpy(xfs_buf_offset(bp,
(uint)bit << XFS_BLI_SHIFT), /* dest */
item->ri_buf[i].i_addr, /* source */
@@ -2089,7 +2134,7 @@
if (log->l_quotaoffs_flag & type)
return;
- xlog_recover_do_reg_buffer(item, bp, buf_f);
+ xlog_recover_do_reg_buffer(mp, item, bp, buf_f);
}
/*
@@ -2190,7 +2235,7 @@
(XFS_BLI_UDQUOT_BUF|XFS_BLI_PDQUOT_BUF|XFS_BLI_GDQUOT_BUF)) {
xlog_recover_do_dquot_buffer(mp, log, item, bp, buf_f);
} else {
- xlog_recover_do_reg_buffer(item, bp, buf_f);
+ xlog_recover_do_reg_buffer(mp, item, bp, buf_f);
}
if (error)
return XFS_ERROR(error);
diff --git a/fs/xfs/xfs_trans_buf.c b/fs/xfs/xfs_trans_buf.c
index 60b6b89..95fff68 100644
--- a/fs/xfs/xfs_trans_buf.c
+++ b/fs/xfs/xfs_trans_buf.c
@@ -966,6 +966,7 @@
ASSERT(atomic_read(&bip->bli_refcount) > 0);
bip->bli_flags |= XFS_BLI_INODE_ALLOC_BUF;
+ bip->bli_format.blf_flags |= XFS_BLI_INODE_NEW_BUF;
}
