[Disco][SRU][PATCH 1/2] btrfs: refactor btrfs_find_device() take fs_devices as argument

Connor Kuehl connor.kuehl at canonical.com
Tue Dec 10 00:48:23 UTC 2019


From: Anand Jain <anand.jain at oracle.com>

CVE-2019-18885

btrfs_find_device() accepts fs_info as an argument and retrieves
fs_devices from fs_info.

Instead use fs_devices, so that this function can be used in non-mount
(during device scanning) context as well.

Signed-off-by: Anand Jain <anand.jain at oracle.com>
Reviewed-by: David Sterba <dsterba at suse.com>
Signed-off-by: David Sterba <dsterba at suse.com>
(cherry picked from commit e4319cd9cacef80a2d289f235b939ab8bd614683)
Signed-off-by: Connor Kuehl <connor.kuehl at canonical.com>
---
 fs/btrfs/dev-replace.c |  6 +++---
 fs/btrfs/ioctl.c       |  5 +++--
 fs/btrfs/scrub.c       |  4 ++--
 fs/btrfs/volumes.c     | 39 ++++++++++++++++++++-------------------
 fs/btrfs/volumes.h     |  4 ++--
 5 files changed, 30 insertions(+), 28 deletions(-)

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index a491447d5d89..3eeeddbdb057 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -111,9 +111,9 @@ int btrfs_init_dev_replace(struct btrfs_fs_info *fs_info)
 		break;
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_STARTED:
 	case BTRFS_IOCTL_DEV_REPLACE_STATE_SUSPENDED:
-		dev_replace->srcdev = btrfs_find_device(fs_info, src_devid,
-							NULL, NULL);
-		dev_replace->tgtdev = btrfs_find_device(fs_info,
+		dev_replace->srcdev = btrfs_find_device(fs_info->fs_devices,
+							src_devid, NULL, NULL);
+		dev_replace->tgtdev = btrfs_find_device(fs_info->fs_devices,
 							BTRFS_DEV_REPLACE_DEVID,
 							NULL, NULL);
 		/*
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 6061d2c3d1cd..3946e5815027 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1650,7 +1650,7 @@ static noinline int btrfs_ioctl_resize(struct file *file,
 		btrfs_info(fs_info, "resizing devid %llu", devid);
 	}
 
-	device = btrfs_find_device(fs_info, devid, NULL, NULL);
+	device = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL);
 	if (!device) {
 		btrfs_info(fs_info, "resizer unable to find device %llu",
 			   devid);
@@ -3186,7 +3186,8 @@ static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
 		s_uuid = di_args->uuid;
 
 	rcu_read_lock();
-	dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
+	dev = btrfs_find_device(fs_info->fs_devices, di_args->devid, s_uuid,
+				NULL);
 
 	if (!dev) {
 		ret = -ENODEV;
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 1aeac70d0531..29bfa1066f17 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -3828,7 +3828,7 @@ int btrfs_scrub_dev(struct btrfs_fs_info *fs_info, u64 devid, u64 start,
 		return PTR_ERR(sctx);
 
 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
-	dev = btrfs_find_device(fs_info, devid, NULL, NULL);
+	dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL);
 	if (!dev || (test_bit(BTRFS_DEV_STATE_MISSING, &dev->dev_state) &&
 		     !is_dev_replace)) {
 		mutex_unlock(&fs_info->fs_devices->device_list_mutex);
@@ -4012,7 +4012,7 @@ int btrfs_scrub_progress(struct btrfs_fs_info *fs_info, u64 devid,
 	struct scrub_ctx *sctx = NULL;
 
 	mutex_lock(&fs_info->fs_devices->device_list_mutex);
-	dev = btrfs_find_device(fs_info, devid, NULL, NULL);
+	dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL);
 	if (dev)
 		sctx = dev->scrub_ctx;
 	if (sctx)
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 1aa34b859219..b6c2973661ea 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2385,11 +2385,11 @@ static struct btrfs_device *btrfs_find_device_by_path(
 	devid = btrfs_stack_device_id(&disk_super->dev_item);
 	dev_uuid = disk_super->dev_item.uuid;
 	if (btrfs_fs_incompat(fs_info, METADATA_UUID))
-		device = btrfs_find_device(fs_info, devid, dev_uuid,
-				disk_super->metadata_uuid);
+		device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
+					   disk_super->metadata_uuid);
 	else
-		device = btrfs_find_device(fs_info, devid,
-				dev_uuid, disk_super->fsid);
+		device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
+					   disk_super->fsid);
 
 	brelse(bh);
 	if (!device)
@@ -2433,7 +2433,8 @@ struct btrfs_device *btrfs_find_device_by_devspec(
 	struct btrfs_device *device;
 
 	if (devid) {
-		device = btrfs_find_device(fs_info, devid, NULL, NULL);
+		device = btrfs_find_device(fs_info->fs_devices, devid, NULL,
+					   NULL);
 		if (!device)
 			return ERR_PTR(-ENOENT);
 	} else {
@@ -2563,7 +2564,8 @@ static int btrfs_finish_sprout(struct btrfs_trans_handle *trans,
 				   BTRFS_UUID_SIZE);
 		read_extent_buffer(leaf, fs_uuid, btrfs_device_fsid(dev_item),
 				   BTRFS_FSID_SIZE);
-		device = btrfs_find_device(fs_info, devid, dev_uuid, fs_uuid);
+		device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
+					   fs_uuid);
 		BUG_ON(!device); /* Logic error */
 
 		if (device->fs_devices->seeding) {
@@ -6621,21 +6623,19 @@ blk_status_t btrfs_map_bio(struct btrfs_fs_info *fs_info, struct bio *bio,
 	return BLK_STS_OK;
 }
 
-struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
-				       u8 *uuid, u8 *fsid)
+struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
+				       u64 devid, u8 *uuid, u8 *fsid)
 {
 	struct btrfs_device *device;
-	struct btrfs_fs_devices *cur_devices;
 
-	cur_devices = fs_info->fs_devices;
-	while (cur_devices) {
+	while (fs_devices) {
 		if (!fsid ||
-		    !memcmp(cur_devices->metadata_uuid, fsid, BTRFS_FSID_SIZE)) {
-			device = find_device(cur_devices, devid, uuid);
+		    !memcmp(fs_devices->metadata_uuid, fsid, BTRFS_FSID_SIZE)) {
+			device = find_device(fs_devices, devid, uuid);
 			if (device)
 				return device;
 		}
-		cur_devices = cur_devices->seed;
+		fs_devices = fs_devices->seed;
 	}
 	return NULL;
 }
@@ -6880,8 +6880,8 @@ static int read_one_chunk(struct btrfs_fs_info *fs_info, struct btrfs_key *key,
 		read_extent_buffer(leaf, uuid, (unsigned long)
 				   btrfs_stripe_dev_uuid_nr(chunk, i),
 				   BTRFS_UUID_SIZE);
-		map->stripes[i].dev = btrfs_find_device(fs_info, devid,
-							uuid, NULL);
+		map->stripes[i].dev = btrfs_find_device(fs_info->fs_devices,
+							devid, uuid, NULL);
 		if (!map->stripes[i].dev &&
 		    !btrfs_test_opt(fs_info, DEGRADED)) {
 			free_extent_map(em);
@@ -7020,7 +7020,8 @@ static int read_one_dev(struct btrfs_fs_info *fs_info,
 			return PTR_ERR(fs_devices);
 	}
 
-	device = btrfs_find_device(fs_info, devid, dev_uuid, fs_uuid);
+	device = btrfs_find_device(fs_info->fs_devices, devid, dev_uuid,
+				   fs_uuid);
 	if (!device) {
 		if (!btrfs_test_opt(fs_info, DEGRADED)) {
 			btrfs_report_missing_device(fs_info, devid,
@@ -7610,7 +7611,7 @@ int btrfs_get_dev_stats(struct btrfs_fs_info *fs_info,
 	int i;
 
 	mutex_lock(&fs_devices->device_list_mutex);
-	dev = btrfs_find_device(fs_info, stats->devid, NULL, NULL);
+	dev = btrfs_find_device(fs_info->fs_devices, stats->devid, NULL, NULL);
 	mutex_unlock(&fs_devices->device_list_mutex);
 
 	if (!dev) {
@@ -7825,7 +7826,7 @@ static int verify_one_dev_extent(struct btrfs_fs_info *fs_info,
 	}
 
 	/* Make sure no dev extent is beyond device bondary */
-	dev = btrfs_find_device(fs_info, devid, NULL, NULL);
+	dev = btrfs_find_device(fs_info->fs_devices, devid, NULL, NULL);
 	if (!dev) {
 		btrfs_err(fs_info, "failed to find devid %llu", devid);
 		ret = -EUCLEAN;
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index c5b00b2e2d38..0a799ab3d916 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -438,8 +438,8 @@ void __exit btrfs_cleanup_fs_uuids(void);
 int btrfs_num_copies(struct btrfs_fs_info *fs_info, u64 logical, u64 len);
 int btrfs_grow_device(struct btrfs_trans_handle *trans,
 		      struct btrfs_device *device, u64 new_size);
-struct btrfs_device *btrfs_find_device(struct btrfs_fs_info *fs_info, u64 devid,
-				       u8 *uuid, u8 *fsid);
+struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices,
+				       u64 devid, u8 *uuid, u8 *fsid);
 int btrfs_shrink_device(struct btrfs_device *device, u64 new_size);
 int btrfs_init_new_device(struct btrfs_fs_info *fs_info, const char *path);
 int btrfs_balance(struct btrfs_fs_info *fs_info,
-- 
2.17.1




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