[kernel] Revert check for read-only block device added in .38 (#672265)

[Chuck Ebbert]

commit b161e65d967a62e8c598485b7a601842cf292225
Author: Chuck Ebbert <cebbert at redhat.com>
Date:   Wed Feb 16 17:04:06 2011 -0500

    Revert check for read-only block device added in .38 (#672265)

 kernel.spec                            |    7 ++++++
 revert-block-check-bdev-readonly.patch |   33 ++++++++++++++++++++++++++++++++
 2 files changed, 40 insertions(+), 0 deletions(-)
---
diff --git a/kernel.spec b/kernel.spec
index b9f3202..0c6a80c 100644
--- a/kernel.spec
+++ b/kernel.spec
@@ -738,6 +738,9 @@ Patch12440: bridge-fix-mglist-corruption-that-leads-to-memory-corruption.patch
 # rhbz#676860
 Patch12441: usb-sierra-add-airprime-direct-ip.patch
 
+# rhbz#672265
+Patch12442: revert-block-check-bdev-readonly.patch
+
 %endif
 
 BuildRoot: %{_tmppath}/kernel-%{KVERREL}-root
@@ -1358,6 +1361,9 @@ ApplyPatch bridge-fix-mglist-corruption-that-leads-to-memory-corruption.patch
 # rhbz#676860
 ApplyPatch usb-sierra-add-airprime-direct-ip.patch
 
+# rhbz#672265
+ApplyPatch revert-block-check-bdev-readonly.patch
+
 # END OF PATCH APPLICATIONS
 
 %endif
@@ -1964,6 +1970,7 @@ fi
 * Wed Feb 16 2011 Chuck Ebbert <cebbert at redhat.com>
 - Add support for Airprime/Sierra USB IP modem (#676860)
 - Make virtio_console built-in on x86_64 (#677713)
+- Revert check for read-only block device added in .38 (#672265)
 
 * Tue Feb 15 2011 Kyle McMartin <kmcmartin at redhat.com> 2.6.38-0.rc5.git0.1
 - Linux 2.6.38-rc5 (81 minutes later...)
diff --git a/revert-block-check-bdev-readonly.patch b/revert-block-check-bdev-readonly.patch
new file mode 100644
index 0000000..6227f04
--- /dev/null
+++ b/revert-block-check-bdev-readonly.patch
@@ -0,0 +1,33 @@
+This reverts commit 75f1dc0d076d1c1168f2115f1941ea627d38bd5a. The revert
+could not be done automatically because changes after that commit
+altered the code too much.
+
+Signed-off-by: Chuck Ebbert <cebbert at redhat.com>
+
+--- a/fs/block_dev.c
++++ b/fs/block_dev.c
+@@ -1215,12 +1215,6 @@ int blkdev_get(struct block_device *bdev
+ 
+ 	res = __blkdev_get(bdev, mode, 0);
+ 
+-	/* __blkdev_get() may alter read only status, check it afterwards */
+-	if (!res && (mode & FMODE_WRITE) && bdev_read_only(bdev)) {
+-		__blkdev_put(bdev, mode, 0);
+-		res = -EACCES;
+-	}
+-
+ 	if (whole) {
+ 		/* finish claiming */
+ 		mutex_lock(&bdev->bd_mutex);
+@@ -1298,6 +1292,11 @@ struct block_device *blkdev_get_by_path(
+ 	if (err)
+ 		return ERR_PTR(err);
+ 
++	if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) {
++		blkdev_put(bdev, mode);
++		return ERR_PTR(-EACCES);
++	}
++
+ 	return bdev;
+ }
+ EXPORT_SYMBOL(blkdev_get_by_path);