-Index: linux-2.6/fs/block_dev.c
+This patch is no longer needed for Lustre. It is only included
+for testing and ease of using the same kernel with older Lustre
+versions. This testing functionality was replaced in Linux 3.0
+by the dm-flakey driver.
+
+This functionality is mainly used during testing, in order to
+simulate a server crash for ldiskfs by discarding all of the
+writes to the filesystem. For recovery testing we could simulate
+this by using a special loopback or DM device that also discards
+writes to the device.
+
+This functionality is also used by target "failback" in order
+to speed up service shutdown and takeover by the other node
+during controlled operation. However, it would also be possible
+to do this by simply allowing all of the in-flight requests to
+complete and then waiting for the service to stop. This will
+also be needed by the DMU-OSD, because discarding of writes on
+a DMU-based target is not safe as it could trigger a storage
+failure if the data is ever read from disk again and the
+checksum does not match that expected by the block pointer.
+
+Index: linux-2.6.18.1/block/ll_rw_blk.c
===================================================================
---- linux-2.6.orig/fs/block_dev.c 2006-07-06 23:41:48.000000000 +0800
-+++ linux-2.6/fs/block_dev.c 2006-07-15 16:20:25.000000000 +0800
-@@ -1118,6 +1118,7 @@ static int __blkdev_put(struct block_dev
- }
- unlock_kernel();
- mutex_unlock(&bdev->bd_mutex);
-+ dev_clear_rdonly(bdev);
- bdput(bdev);
- return ret;
- }
-Index: linux-2.6/block/ll_rw_blk.c
-===================================================================
---- linux-2.6.orig/block/ll_rw_blk.c 2006-07-10 22:30:08.000000000 +0800
-+++ linux-2.6/block/ll_rw_blk.c 2006-07-15 16:15:14.000000000 +0800
-@@ -2993,6 +2993,8 @@ static void handle_bad_sector(struct bio
+--- linux-2.6.18.1.orig/block/ll_rw_blk.c
++++ linux-2.6.18.1/block/ll_rw_blk.c
+@@ -3067,6 +3067,8 @@ static void handle_bad_sector(struct bio
set_bit(BIO_EOF, &bio->bi_flags);
}
/**
* generic_make_request: hand a buffer to its device driver for I/O
* @bio: The bio describing the location in memory and on the device.
-@@ -3076,6 +3078,12 @@ end_io:
+@@ -3151,6 +3153,12 @@ end_io:
if (unlikely(test_bit(QUEUE_FLAG_DEAD, &q->queue_flags)))
goto end_io;
-+ /* this is cfs's dev_rdonly check */
-+ if (bio->bi_rw == WRITE &&
-+ dev_check_rdonly(bio->bi_bdev)) {
-+ bio_endio(bio, bio->bi_size, 0);
-+ break;
-+ }
-
+
++ /* this is cfs's dev_rdonly check */
++ if (bio_rw(bio) == WRITE && dev_check_rdonly(bio->bi_bdev)) {
++ bio_endio(bio, bio->bi_size, 0);
++ break;
++ }
++
/*
* If this device has partitions, remap block n
-@@ -3673,6 +3681,91 @@ void swap_io_context(struct io_context *
+@@ -3765,6 +3773,91 @@ void swap_io_context(struct io_context *
*ioc2 = temp;
}
EXPORT_SYMBOL(swap_io_context);
/*
* sysfs parts below
-Index: linux-2.6/include/linux/fs.h
+Index: linux-2.6.18.1/fs/block_dev.c
+===================================================================
+--- linux-2.6.18.1.orig/fs/block_dev.c
++++ linux-2.6.18.1/fs/block_dev.c
+@@ -1059,6 +1059,7 @@ static int __blkdev_put(struct block_dev
+ if (bdev != bdev->bd_contains)
+ victim = bdev->bd_contains;
+ bdev->bd_contains = NULL;
++ dev_clear_rdonly(bdev);
+ }
+ unlock_kernel();
+ mutex_unlock(&bdev->bd_mutex);
+Index: linux-2.6.18.1/include/linux/fs.h
===================================================================
---- linux-2.6.orig/include/linux/fs.h 2006-07-15 16:14:58.000000000 +0800
-+++ linux-2.6/include/linux/fs.h 2006-07-15 16:15:14.000000000 +0800
-@@ -1648,6 +1648,10 @@ extern void file_kill(struct file *f);
+--- linux-2.6.18.1.orig/include/linux/fs.h
++++ linux-2.6.18.1/include/linux/fs.h
+@@ -1685,6 +1685,10 @@ extern void file_kill(struct file *f);
struct bio;
extern void submit_bio(int, struct bio *);
extern int bdev_read_only(struct block_device *);