[PATCH] log replay should not overwrite newer ondisk inodes

Lachlan McIlroy
2007-08-30T02:32:00Z

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Log replay of clustered inodes currently ignores the flushiter
field in the inode that is used to determine if the on-disk inode
is more up to date than the copy in the log. As a result during
log replay the newer inode is being overwritten with an older
version and file size updates are being lost.

I haven't handled the case of the flushiter counter overflowing
but that shouldn't be a problem in this case. The log buffer
contains newly created inodes so their flushiter values will be 0
and the on-disk inodes should not be much greater.

Lachlan

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--- fs/xfs/xfs_log_recover.c_1.322 2007-08-27 17:45:45.000000000 +1000
+++ fs/xfs/xfs_log_recover.c 2007-08-30 11:50:44.000000000 +1000
@@ -1866,6 +1866,27 @@ xlog_recover_do_inode_buffer(
}

/*
+ * Check if we need to recover an inode from a buffer
+ */
+int
+xfs_recover_inode(
+ char *dest,
+ char *src)
+{
+ xfs_dinode_t *dip = (xfs_dinode_t *)dest;
+ xfs_dinode_t *dilp = (xfs_dinode_t*)src;
+
+ if ((be16_to_cpu(dip->di_core.di_magic) == XFS_DINODE_MAGIC) &&
+ (be16_to_cpu(dilp->di_core.di_magic) == XFS_DINODE_MAGIC) &&
+ (be16_to_cpu(dilp->di_core.di_flushiter) <
+ be16_to_cpu(dip->di_core.di_flushiter))) {
+ return 1;
+ }
+
+ return 0;
+}
+
+/*
* Perform a 'normal' buffer recovery. Each logged region of the
* buffer should be copied over the corresponding region in the
* given buffer. The bitmap in the buf log format structure indicates
@@ -1917,6 +1938,13 @@ xlog_recover_do_reg_buffer(
-1, 0, XFS_QMOPT_DOWARN,
"dquot_buf_recover");
}
+ /*
+ * Sanity check if this is an inode buffer.
+ */
+ if (!error)
+ error = xfs_recover_inode(xfs_buf_offset(bp,
+ (uint)bit << XFS_BLI_SHIFT),
+ item->ri_buf[i].i_addr);
if (!error)
memcpy(xfs_buf_offset(bp,
(uint)bit << XFS_BLI_SHIFT), /* dest */