3.0 patches

2 files changed, 146 insertions, 0 deletions

diff --git a/queue-3.0/btrfs-detect-wether-a-device-supports-discard.patch b/queue-3.0/btrfs-detect-wether-a-device-supports-discard.patch
new file mode 100644
index 0000000000..95d5ed0fb3
--- /dev/null
+++ b/queue-3.0/btrfs-detect-wether-a-device-supports-discard.patch
@@ -0,0 +1,145 @@
+From d5e2003c2bcda93a8f2e668eb4642d70c9c38301 Mon Sep 17 00:00:00 2001
+From: Josef Bacik <josef@redhat.com>
+Date: Thu, 4 Aug 2011 14:52:27 +0000
+Subject: Btrfs: detect wether a device supports discard
+
+From: Josef Bacik <josef@redhat.com>
+
+commit d5e2003c2bcda93a8f2e668eb4642d70c9c38301 upstream.
+
+We have a problem where if a user specifies discard but doesn't actually support
+it we will return EOPNOTSUPP from btrfs_discard_extent.  This is a problem
+because this gets called (in a fashion) from the tree log recovery code, which
+has a nice little BUG_ON(ret) after it, which causes us to fail the tree log
+replay.  So instead detect wether our devices support discard when we're adding
+them and then don't issue discards if we know that the device doesn't support
+it.  And just for good measure set ret = 0 in btrfs_issue_discard just in case
+we still get EOPNOTSUPP so we don't screw anybody up like this again.  Thanks,
+
+Signed-off-by: Josef Bacik <josef@redhat.com>
+Signed-off-by: Chris Mason <chris.mason@oracle.com>
+Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
+
+---
+ fs/btrfs/extent-tree.c |   12 ++++++++++--
+ fs/btrfs/volumes.c     |   17 +++++++++++++++++
+ fs/btrfs/volumes.h     |    2 ++
+ 3 files changed, 29 insertions(+), 2 deletions(-)
+
+--- a/fs/btrfs/extent-tree.c
++++ b/fs/btrfs/extent-tree.c
+@@ -1784,6 +1784,9 @@ static int btrfs_discard_extent(struct b
+ 
+ 
+ 		for (i = 0; i < multi->num_stripes; i++, stripe++) {
++			if (!stripe->dev->can_discard)
++				continue;
++
+ 			ret = btrfs_issue_discard(stripe->dev->bdev,
+ 						  stripe->physical,
+ 						  stripe->length);
+@@ -1791,11 +1794,16 @@ static int btrfs_discard_extent(struct b
+ 				discarded_bytes += stripe->length;
+ 			else if (ret != -EOPNOTSUPP)
+ 				break;
++
++			/*
++			 * Just in case we get back EOPNOTSUPP for some reason,
++			 * just ignore the return value so we don't screw up
++			 * people calling discard_extent.
++			 */
++			ret = 0;
+ 		}
+ 		kfree(multi);
+ 	}
+-	if (discarded_bytes && ret == -EOPNOTSUPP)
+-		ret = 0;
+ 
+ 	if (actual_bytes)
+ 		*actual_bytes = discarded_bytes;
+--- a/fs/btrfs/volumes.c
++++ b/fs/btrfs/volumes.c
+@@ -500,6 +500,9 @@ static int __btrfs_close_devices(struct
+ 			fs_devices->rw_devices--;
+ 		}
+ 
++		if (device->can_discard)
++			fs_devices->num_can_discard--;
++
+ 		new_device = kmalloc(sizeof(*new_device), GFP_NOFS);
+ 		BUG_ON(!new_device);
+ 		memcpy(new_device, device, sizeof(*new_device));
+@@ -508,6 +511,7 @@ static int __btrfs_close_devices(struct
+ 		new_device->bdev = NULL;
+ 		new_device->writeable = 0;
+ 		new_device->in_fs_metadata = 0;
++		new_device->can_discard = 0;
+ 		list_replace_rcu(&device->dev_list, &new_device->dev_list);
+ 
+ 		call_rcu(&device->rcu, free_device);
+@@ -547,6 +551,7 @@ int btrfs_close_devices(struct btrfs_fs_
+ static int __btrfs_open_devices(struct btrfs_fs_devices *fs_devices,
+ 				fmode_t flags, void *holder)
+ {
++	struct request_queue *q;
+ 	struct block_device *bdev;
+ 	struct list_head *head = &fs_devices->devices;
+ 	struct btrfs_device *device;
+@@ -603,6 +608,12 @@ static int __btrfs_open_devices(struct b
+ 			seeding = 0;
+ 		}
+ 
++		q = bdev_get_queue(bdev);
++		if (blk_queue_discard(q)) {
++			device->can_discard = 1;
++			fs_devices->num_can_discard++;
++		}
++
+ 		device->bdev = bdev;
+ 		device->in_fs_metadata = 0;
+ 		device->mode = flags;
+@@ -1542,6 +1553,7 @@ error:
+ 
+ int btrfs_init_new_device(struct btrfs_root *root, char *device_path)
+ {
++	struct request_queue *q;
+ 	struct btrfs_trans_handle *trans;
+ 	struct btrfs_device *device;
+ 	struct block_device *bdev;
+@@ -1611,6 +1623,9 @@ int btrfs_init_new_device(struct btrfs_r
+ 
+ 	lock_chunks(root);
+ 
++	q = bdev_get_queue(bdev);
++	if (blk_queue_discard(q))
++		device->can_discard = 1;
+ 	device->writeable = 1;
+ 	device->work.func = pending_bios_fn;
+ 	generate_random_uuid(device->uuid);
+@@ -1646,6 +1661,8 @@ int btrfs_init_new_device(struct btrfs_r
+ 	root->fs_info->fs_devices->num_devices++;
+ 	root->fs_info->fs_devices->open_devices++;
+ 	root->fs_info->fs_devices->rw_devices++;
++	if (device->can_discard)
++		root->fs_info->fs_devices->num_can_discard++;
+ 	root->fs_info->fs_devices->total_rw_bytes += device->total_bytes;
+ 
+ 	if (!blk_queue_nonrot(bdev_get_queue(bdev)))
+--- a/fs/btrfs/volumes.h
++++ b/fs/btrfs/volumes.h
+@@ -48,6 +48,7 @@ struct btrfs_device {
+ 	int writeable;
+ 	int in_fs_metadata;
+ 	int missing;
++	int can_discard;
+ 
+ 	spinlock_t io_lock;
+ 
+@@ -104,6 +105,7 @@ struct btrfs_fs_devices {
+ 	u64 rw_devices;
+ 	u64 missing_devices;
+ 	u64 total_rw_bytes;
++	u64 num_can_discard;
+ 	struct block_device *latest_bdev;
+ 
+ 	/* all of the devices in the FS, protected by a mutex
diff --git a/queue-3.0/series b/queue-3.0/series
index 07bb57d881..c473522f40 100644
--- a/queue-3.0/series
+++ b/queue-3.0/series
@@ -10,3 +10,4 @@ pnfs-obj-bug-when-we-are-running-out-of-bio.patch
 nfsv4.1-fix-the-callback-highest_used_slotid-behaviour.patch
 nfsv4.1-return-nfs4err_badsession-to-callbacks-during.patch
 x86-mtrr-lock-stop-machine-during-mtrr-rendezvous-sequence.patch
+btrfs-detect-wether-a-device-supports-discard.patch