For the matter of completeness we need to check if the device being scanned has features that are known to the kernel. As of now if it doesn't - the mount will fails, then what is the point in having those devices added to the btrfs_fs_devices list at device_list_add().
So block those devices at scan. Which means the original block at open_ctee() won't reach in case of device with unsupported feature. But I am leaving that code as it is. without deleting. Signed-off-by: Anand Jain <[email protected]> --- fs/btrfs/volumes.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index b52197b..fcc9e57 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -976,6 +976,7 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, u64 transid; u64 total_devices; u64 bytenr; + u64 features; /* * we would like to check all the supers, but that would make @@ -996,6 +997,15 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, if (btrfs_read_disk_super(bdev, bytenr, &page, &disk_super)) goto error_bdev_put; + features = btrfs_super_incompat_flags(disk_super) & + ~BTRFS_FEATURE_INCOMPAT_SUPP; + if (features) { + printk(KERN_ERR \ + "BTRFS: couldn't scan, unsupported optional features (%Lx)\n", + features); + ret = -EOPNOTSUPP; + goto error_disk_super; + } devid = btrfs_stack_device_id(&disk_super->dev_item); transid = btrfs_super_generation(disk_super); total_devices = btrfs_super_num_devices(disk_super); @@ -1010,6 +1020,7 @@ int btrfs_scan_one_device(const char *path, fmode_t flags, void *holder, if (!ret && fs_devices_ret) (*fs_devices_ret)->total_devices = total_devices; +error_disk_super: btrfs_release_disk_super(page); error_bdev_put: -- 2.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
